Materials and method for enhancing muscle contraction and mitochondrial function

Abstract

Reduced muscle contractility and mitochondrial bioenergetics are the hallmarks of systolic heart failure. There is currently no therapy targeting both. The present invention shows that gene delivery of Perml via adeno-associated virus (AAV) simultaneously enhances cardiac contractility and mitochondrial biogenesis. Moreover, PERM1 interacts with Troponin C (TnC), a key contractile protein in striated muscle, and that AAV -Perml led to upregulation of TnC. Thus, gene delivery of Perml can be a novel therapeutic approach to treat or prevent systolic heart failure by simultaneously restoring cardiac contractility and mitochondrial bioenergetics.

Description

[0001]MATERIALS AND METHOD FOR ENHANCING MUSCLE CONTRACTION AND MITOCHONDRIAL FUNCTION CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application Serial No. 63 / 695,185, filed September 16, 2024, and U.S. Provisional Application Serial No. 63 / 695,673, filed September 17, 2024, the disclosures of which are hereby incorporated by reference in its entirety, including all figures, tables, and drawings. SEQUENCE LISTING The Sequence Listing for this application is labeled “VTI-104CP-SeqList-17Sep24.xml,” which was created on September 17, 2024, and is 66,569 bytes. The Sequence Listing is incorporated herein by reference in its entirety. GOVERNMENT SUPPORT The subject invention was made with government support under grant number R01HL156667 awarded by the National Institutes of Health. The government has certain rights in the invention. BACKGROUND OF THE INVENTION Heart failure (HF) affects 6 million Americans and about 64.3 million people worldwide (Virani et al., American Heart Association Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Committee. Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association. Circulation 141(9) (2020) e139-e596.). Approximately half of these patients have heart failure with reduced left ventricular (LV) ejection fraction (HFrEF). Despite improvements in heart failure management, survival rates remain very low, as 50% of heart failure patients die with 5 years after the first hospitalization. HFrEF (systolic heart failure) is characterized by a decreased ability of the heart to pump blood through the body due to the weakened cardiac muscle. There is currently no medication that enhances heart contractility. Over the last few decades, numerous attempts have been made to develop strategies using positive cardiac inotropes to improve systolic function; however, definitive clinical trials have failed to improve survival, and no positive inotrope is currently approved for the treatment of systolic heart failure. The current standard of care for HF includes, for example, the simultaneous administration of one or more of the following classes of drugs, e.g., angiotensin-converting enzyme (ACE) inhibitors, angiotensin II-receptor blockers (ARBs), beta-blockers, mineralocorticoid receptor agents like mineralocorticoid-receptor antagonists (MRAs), angiotensin receptor-neprilysin inhibitors (ARNIs), digoxin, diuretics, heart pump medication, selective sinus node inhibitors, blood vessel dilators, and calcium channel blockers. Morbidity and mortality for patients with HF remain high, and patient outcomes need improvement. Efforts to enhance cardiac contractility for HFrEF therapy have long focused on the sarcomere, the fundamental contractile unit of muscle fibers, known as myofibrils, composed of thin actin and thick myosin filaments. Muscle contraction occurs when Ca2+ions, released from the sarcoplasmic reticulum (SR), bind to troponin C (TnC) on the actin filaments, promoting steric movement of tropomyosin on actin that reveals binding sites for myosin heads, allowing the formation of cross-bridges. These cross-bridges then utilize ATP to cycle and generate force. Two classes of agents, inotropes and myotropes, aim to enhance cardiac contractility by either increasing the force of contraction or improving the efficiency of contractions, respectively. An issue with both inotropes and myotropes is that as they drive higher sarcomere contractility, it increases ATP utilization, which is often compromised in HFrEF, thereby coming with an increased risk of worsening patient outcomes. Thus, despite on-going efforts to improve systolic function and energy metabolism, there are still no FDA-approved drugs that efficiently enhance cardiac contractility while preserving energy coupling in HFrEF. Additional methods of treating patients with HF, and especially HFrEF, are needed to reduce cardiovascular mortality, reduce heart failure events and the worsening of HF symptoms, and improve patient outcomes by slowing disease progression. Thus, there is a need to develop novel methods for treating diseases or disorders with reduced heart contractility including cardiovascular diseases such as heart failure. BRIEF SUMMARY OF THE INVENTION The subject invention provides products, compositions, and methods for preventing or treating diseases or disorders associated with impaired muscle contraction and mitochondrial function. In preferred embodiments, the disease or disorder is a cardiovascular disease or aging- related disease. In a specific embodiment, the cardiovascular disease is diabetic cardiomyopathy or heart failure, in particular, heart failure with reduced ejection fraction (HFrEF). The subject invention also provides methods for delivering therapeutic molecules to cells, tissues, and organs in a subject with impaired muscle contraction and mitochondrial function. Preferably, the products, and compositions of the subject invention can be used as a gene therapy for delivering the therapeutic agents to cells, tissue or organs as a treatment for diseases or disorders associated with impaired muscle contraction and mitochondrial function such as cardiovascular diseases. In accordance with the subject invention, peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1) - and estrogen-related receptor (ERR)-induced regulator in muscle 1 (PERM1) regulates cardiac contractility, which involves binding of PERM1 to troponin C (TnC), an essential regulator of contractile force, and an increase in TnC protein expression. In one embodiment of the subject invention, adeno-associated virus (AAV)-mediated gene delivery of Perm1 simultaneously promotes cardiac contractility and mitochondrial biogenesis. Advantageously, gene delivery of Perm1 serves as a new therapeutic approach to treat conditions where muscle contraction and mitochondrial function are compromised, such as heart failure (in particular, HFrEF), cardiomyopathy (e.g., diabetic cardiomyopathy), and aging. In one embodiment, the subject invention provides an AAV gene therapy vector comprising a polynucleotide encoding a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein. In one embodiment, the AAV gene therapy vector further comprises a promoter, a terminator, and optionally, ITR sequences at 3’ and 5’ ends, wherein the promotor is selected from chicken β-actin (CBA), chicken β-actin hybrid (CBh), cytomegalovirus (CMV), short CMV early enhancer / chicken β-actin / short β-globulin intron (sCAG), mouse phosphoglycerate kinase (PGK), and human synapsin (SYN); and wherein the terminator is selected from bovine growth hormone polyadenylation signal (BGH polyA), human growth hormone polyadenylation signal (hGH polyA), simian virus 40 (SV40) polyA, and synthetic polyA. In specific embodiments, the AAV gene therapy vector is serotype 1, 2, 4, 5, 6, 8 or 9. In a specific embodiment, the AAV gene therapy vector is AAV9. In one embodiment, the subject invention provides a composition comprising the AAV gene therapy vector comprising a polynucleotide encoding a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein. In one embodiment, the subject invention provides a cell transduced with the AAV gene therapy vector comprising a polynucleotide encoding a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with PERM1 protein. In one embodiment, the subject invention provides a method for treating a disease associated with impaired muscle contraction and mitochondrial function, the method comprising administering, to a subject in need thereof: (1) a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein; (2) a polynucleotide sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a nucleic acid sequence encoding a PERM1 protein; (3) a PERM1 protein or a variant or fragment thereof; (4) an AAV gene therapy vector comprising a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein; or (5) an AAV gene therapy vector comprising a polynucleotide sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a nucleic acid sequence encoding a PERM1 protein. In specific embodiments, the disease is a cardiovascular disease (e.g., heart failure or diabetic cardiomyopathy) or an aging-related disease. In a specific embodiment, the cardiovascular disease is heart failure with reduced ejection fraction (HFrEF). The administration can be, for example, oral, subcutaneous, intradermal, intravenous, intravascular, intramuscular, intraperitoneal, or intrasternal administration. In specific embodiments, the subject invention provides a method for enhancing cardiac contractility of a subject with heart failure, the method comprising administering to the subject one of the following: (1) a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with the PERM1 protein; (2) a polynucleotide sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a nucleic acid sequence encoding a PERM1 protein; (3) PERM1 protein or a variant or fragment thereof; and (4) an AAV gene therapy vector comprising the polynucleotide of (1) or (2). In a specific embodiment, the subject with heart failure has HFrEF. In certain embodiments, the method further comprises assessing / measuring / determining systolic and diastolic left ventricular (LV) function, assessing / measuring / determining diastolic and systolic LV diameters, assessing / measuring / determining LV systolic wall thickness and / or assessing / measuring / determining VO2max. In certain embodiments, the PERM1 nucleic acid and / or protein can be delivered via exosomes, naturally occurring lipid membrane-enclosed vesicles. These vesicles carry various types of cellular cargo, including lipids, nucleic acids, and proteins, and can facilitate the targeted delivery of therapeutic molecules. Advantages of using exosomes for Perm1 delivery include their low immunogenicity, reducing the risk of an immune response, and their potential for cell-specific targeting, which can enhance delivery efficiency to the desired tissues or cells. BRIEF DESCRIPTION OF THE DRAWINGS Figures 1A-1O. AAV-Perm1 enhances cardiac contractility in WT mice. (A-B) Latency in PERM1 expression lasts up to 4 weeks after AAV-Perm1 injection. Red stars indicate the time points echocardiography was performed. (C-H) Western blotting analysis of PERM1 expression in different organs 4 weeks after AAV-GFP (control) and AAV-Perm1 injection (n=7 / group). (C-D) PERM1 expression in the heart (p<0.0001 by unpaired two-sided t-test). (E-F) PERM1 expression in the skeletal muscle (NS by unpaired two-sided t-test). (G-H) PERM1 expression in the adipose tissue (NS by unpaired two-sided t-test). (I-J) Representative M-mode echocardiographic images before and after injection of AAV-GFP or AAV-Perm1. (K-M) Fold-change of ejection fraction (K), LV diameter in systole (L), and LV diameter in diastole (M) due to AAV injection (n=13 AAV-GFP and n=17 AAV-Perm1, analysis by Mann-Whitney test). (N-O) correlation plots of the change in ejection faction (Delta EF) due to AAV injection as the function of ejection fraction (EF) before AAV injection. The plots are obtained from AAV-GFP (N) and AAV-Perm1 (O) groups. In AAV-Perm1 group, Delta EF is inversely correlated with EF before injection, whereas there is no correlation in AAV-GFP group. **: p<0.01, ***: p<0.001, ****p<0.0001 Figures 2A-2M. AAV-Perm1 does not induce anatomical hypertrophy or fibrosis, but does induce subtle changes in cardiomyocyte length and volume. (A) Heart weight (HW) to body weight (BW) (n=7 / group). (B) Heart weight (HW) to tibial length (TL) (n=7 / group). (C) Lung weight (LW) to tibial length (TL) (n=7 / group). (D-E) Confocal images of heart sections stained with fluorophore-conjugated WGA (n=7 / group). (F-G) 3D segmentation of cardiomyocytes obtained from WGA-stained heart preparations. (H-I) Cumulative frequency distribution of cell length (H) and volume (I). p-values are by Kolmogorov-Smirnov test. (J-K) Representative images of Trichrome stained heart sections (n=3 / group). (L) Area percentage occupied by collagen. (M) Gene expression of Perm1, Nppb, Col3a1, Col5a2, CaMKIIa, CaMKIIb,CaMKIId, and CaMKIIg measured using heart samples that were harvested 4 weeks after injection of either AAV-GFP or AAV-Perm1 (n=7 / group). *: p<0.05 by unpaired two-sided t-test. Figures 3A-3E. AAV-Perm1 promotes mitochondrial biogenesis and enhances binding of PERM1 to TnC. (A) Co-IP of cardiac tissue from AAV-Perm1 mice showing the interaction of PERM1 with TnC. (B-D) Western blotting analysis showing upregulation of PGC-1α and TnC in the heart from AAV-Perm1 mice (n=7 / group). (E) AAV-Perm1 increased mitochondrial copy number in the heart (n=4 / group). *p<0.05; **p<0.01 by unpaired two-sided t-test. Figures 4A-4J show AAV-Perm1 prevents the major symptoms of heart failure during pressure overload in mice. A, Experimental design of the preventative study using AAV-Perm1 in mice. Blue triangles indicate time points at which echocardiography was performed. B-C, Western blot analysis of cardiac tissue showing that TAC-induced downregulation of PERM1 was normalized by AAV-Perm1. D-E, Left ventricular ejection fraction (LVEF) in Sham and TAC mice at 8 weeks post-TAC, along with representative M-mode echocardiographic images for each group. The decline in LVEF observed in TAC mice was fully prevented by AAV-Perm1. F, Heart weight-to-body weight (HW / BW) ratio was increased by TAC, while no significant difference was observed between AAVGFP Sham and AAV-Perm1 TAC groups, indicating that AAV-Perm1 prevented pathological cardiac hypertrophy. G-H, Masson’s trichrome staining of cardiac tissue revealed increased fibrosis in TAC hearts, which was suppressed by AAV-Perm1. I-J, qPCR analysis of cardiac tissue showed that expression of Nppb (BNP), a marker of cardiac stress, was increased by TAC but was suppressed by AAV-Perm1 (I), whereas expression of Col3a1, a gene involved in collagen formation, was increased in a subset of AAV-GFP mice subjected to TAC, was not significantly affected overall (J). *: p<0.05, **:p<0.01,***:p<0.001, ****p<0.0001, ns: not significant, by two-way ANOVA. Figures 5A-5P show preserved mitochondrial respiration capacity by AAV-Perm1 during pressure overload. Mitochondria were isolated from heart tissue of AAV-GFP and AAV-Perm1 treated mice post-TAC (8 weeks). Pyruvate / malate (Pyr / M, left panels) and octanoylcarnitine / malate (Oct / M, right panels) were used as mitochondrial substrates. (A-D) Flux of O2and the Max JO2as a function of ATP free energy (deltaGATP). (E-H) Conductance, a linear range of JO2and the changes in mitochondrial JO2. (I-L) Flox of H2O2(JH2O2), showing H2O2emission from heart mitochondrial energized with Pyr / M (I-J) and Oct / M (K-L) under increasing ATP free energies. (M-P) Percentage electron leak (%=JH2O2 / JO2*100) was increased by TAC in AAV-GFP groups with Pyr / M, which was limited at diminished rates of bioenergetic demand. Percentage electron leak was not changed with Oct / M. Figures 6A-6T show AAV-PERM1 preserves mitochondrial biogenesis and key regulators of mitochondrial bioenergetics during pressure overload. A–P, Western blot analysis of transcription factors, cofactors involved in mitochondrial bioenergetics, selected components of electron transport chain, selected key enzymes of fatty acid oxidation (FAO), and glucose transporters. (n=5 AAV-GFP-Sham, n=3 AAV-GFP-TAC, n=4 AAV-Perm1-Sham, n=6 AAV- Perm1-TAC). Q, Quantification of mitochondrial DNA copy number showing a reduction in GFP TAC hearts, but full preservation by AAV-Perm1 treatment. (n=5 AAV-GFP-Sham, n=3 AAV- GFP-TAC, n=7 AAV-Perm1-Sham, n=4 AAV-Perm1-TAC). R–T, Western blot analysis of proteins involved in mitophagy. Statistical comparisons presented are results of post-hoc pairwise Sidak test applied after two-way ANOVA. ****: p<0.0001, ***: p<0.001, *: p<0.05, mean ± SEM, ns: not significant. Figures 7A-7H show metabolomic profiling of AAV-GFP and AAV-Perm1 hearts subjected to Sham or TAC. A–C, Metabolomic profiles of AAV-GFP Sham and AAV-GFP TAC hearts. The principal component analysis (PCA) plot shows a distinct separation between TAC and Sham groups, indicating altered metabolomic profiles in response to TAC (A, p<0.05). Pathway analysis (B) and enrichment analysis (C) highlight specific metabolic pathways affected by TAC. D–E, Comparison of AAV-Perm1 Sham and AAV-Perm1 TAC hearts. The PCA plot shows no significant separation between the two groups (D, p>0.05), suggesting that AAV-Perm1 preserves a metabolomic profile in TAC hearts comparable to Sham. F–H, Comparison of AAV-GFP TAC and AAV-Perm1 TAC hearts. A distinct separation in metabolomic profiles is observed (F). TAC- induced accumulation of TCA cycle intermediates (malate, fumarate, succinate) and spermidine is attenuated in AAV-Perm1 hearts (G–H). Figures 8A-8D show AAV-Perm1 prevents TAC-induced elevation of O-GlcNAcylation. Western blot analysis (A) shows a significant increase in total O-GlcNAcylated proteins at both high molecular weight (HMW, Panel B) and low molecular weight (LMW, Panel C) ranges, as well as increased OGT expression in GFP-TAC hearts compared to GFP-Sham hearts (D), with no significant change in OGA levels (E). In contrast, AAV-Perm1 reduced total O-GlcNAcylated proteins of both HMW and LMW (B-C) and OGT expression (D), and these suppressed levels were maintained during pressure overload. O-GlcNAcylated proteins were quantified separately for HMW (≥75 kDa) and LMW (<75 kDa) fractions (see Methods for details). Statistical comparisons presented are results of post-hoc pairwise Sidak test applied after two-way ANOVA . ****: p<0.0001, ***: p<0.001, *: p<0.05, mean ± SEM. Figures 9A-9G show PERM1 interacts with creatine kinase (CK) and promotes co- localization of CK with Troponin C (TnC). A-B, Co-immunoprecipitation (Co-IP) assays showing that PERM1 interacts with CK in WT hearts (A), and that TnC forms complexes with both CK and PERM1 in WT and AAV-Perm1-treated hearts (B). C-D, Super-resolution stochastic optical reconstruction microscopy (STORM) analysis of mouse cardiac tissue. STORM point-cloud localizations showing the spatial distribution of PERM1 and TnC in heart sections from AAV- Perm1-treated mice (C), with corresponding cross-pair correlation functions indicating significant colocalization (D, n=4). E–G, STORM localizations of TnC and CK in AAV-Perm1 (E) and Perm1-KO (F) hearts. Cross-pair correlation analysis (G) reveals enhanced colocalization of TnC and CK in PERM1-overexpressing hearts compared to Perm1-KO hearts (n=4 per group). Figure 10 shows AAV-PERM1 vector modified by attachment of FLAG sequence to its C-terminus (left) has a stronger inotropic effect than AAV-Perm1 without FLAG (right). LVEF, Left Ventricular Ejection Fraction. Pre, before AAV injection. Post, 4 weeks after AAV injection. *, p <0.05; ns, not significant by RMANOVA with Sidak post-hoc multiple comparisons test. BRIEF DESCRIPTION OF SEQUENCES SEQ ID NO: 1 is an amino acid sequence of FLAG octapeptide contemplated for use according to the subject invention. SEQ ID NO: 2 is a nucleic acid sequence of PERM1 gene contemplated for use according to the subject invention. SEQ ID NO: 3 is an amino acid sequence of PERM1 protein contemplated for use according to the subject invention. SEQ ID NO: 4 is a nucleic acid sequence of PERM1 gene contemplated for use according to the subject invention. SEQ ID NOs: 5-7 are amino acid sequences of PERM1 protein contemplated for use according to the subject invention. SEQ ID NOs: 8 and 9 are nucleic acid sequences of gene therapy vectors contemplated for use according to the subject invention. SEQ ID NOs: 10 and 11 are nucleic acid sequences of AAV vectors contemplated for use according to the subject invention. SEQ ID NO: 12 is a nucleic acid sequence of PERM1 gene contemplated for use according to the subject invention. DETAILED DESCRIPTION OF THE INVENTION The subject invention provides products, compositions, and methods for treating or preventing, for example, cardiovascular diseases, such as heart failure, in particular, heart failure with reduced ejection fraction (HFrEF) in a subject. The subject invention also provides methods for delivering therapeutic molecules to cardiovascular cells, tissues, and organs in a subject. Preferably, the products, and compositions of the subject invention can be used as a gene therapy for delivering the therapeutic agents to cells, tissue or organs as a treatment for cardiovascular diseases. In one embodiment, the subject invention provides the use of PERM1 nucleic acids and / or protein as a therapeutic agent to treat or prevent diseases or disorders associated with impaired muscle contraction and mitochondrial function, such as cardiovascular diseases or disorders. In certain embodiments, polynucleotides encoding a PERM1 protein or a variant or fragment thereof of the present invention can be provided in an expression construct. Expression constructs of the invention generally include regulatory elements that are functional in the intended host cell in which the expression construct is to be expressed. Thus, a person of ordinary skill in the art can select regulatory elements for use in bacterial host cells, yeast host cells, plant host cells, insect host cells, mammalian host cells, and human host cells. Regulatory elements include promoters, transcription termination sequences, translation termination sequences, enhancers, and polyadenylation elements. As used herein, the term “expression construct” refers to a combination of nucleic acid sequences that provides for transcription of an operably linked nucleic acid sequence. As used herein, the term “operably linked” refers to a juxtaposition of the components described wherein the components are in a relationship that permits them to function in their intended manner. In general, operably linked components are in contiguous relation. In certain embodiments, an expression construct of the invention can comprise a promoter sequence operably linked to a polynucleotide sequence of the invention, for example a sequence encoding a PERM1 protein or a variant or fragment thereof of the invention. Promoters can be incorporated into a polynucleotide using standard techniques known in the art. Multiple copies of promoters or multiple promoters can be used in an expression construct of the invention. In a preferred embodiment, a promoter can be positioned about the same distance from the transcription start site in the expression construct as it is from the transcription start site in its natural genetic environment. Some variation in this distance is permitted without substantial decrease in promoter activity. A transcription start site is typically included in the expression construct. In certain embodiments, expression constructs of the invention may optionally contain a transcription termination sequence, a translation termination sequence, a sequence encoding a signal peptide, and / or enhancer elements. Transcription termination regions can typically be obtained from the 3' untranslated region of a eukaryotic or viral gene sequence. Transcription termination sequences can be positioned downstream of a coding sequence to provide for efficient termination. A signal peptide sequence is a short amino acid sequence typically present at the amino terminus of a protein that is responsible for the relocation of an operably linked mature polypeptide to a wide range of post-translational cellular destinations, ranging from a specific organelle compartment to sites of protein action and the extracellular environment. In certain embodiments, classical enhancers are cis-acting elements that increase gene transcription and can also be included in the expression construct. Classical enhancer elements are known in the art, and include, but are not limited to, the CaMV 35S enhancer element, cytomegalovirus (CMV) early promoter enhancer element, and the SV40 enhancer element. Intron-mediated enhancer elements that enhance gene expression are also known in the art. These elements must be present within the transcribed region and are orientation dependent. In certain embodiments, polynucleotides of the present invention can be composed of either RNA or DNA. Preferably, the polynucleotides are composed of DNA. The subject invention also encompasses those polynucleotides that are complementary in sequence to the polynucleotides disclosed herein. Polynucleotides and polypeptides of the invention can be provided in purified or isolated form. In specific embodiments, exemplary PERM1 genes can be found in NIH GenBank with Gene ID 84808 or 74183. Exemplary PERM1 proteins can be found with protein accession Nos. NP_001381642.1, NP_001278296.2, NP_001356827.1, NP_001278295.1, NP_001356826.1, NP_766005.2, and XP_006539275.1. In specific embodiments, the polynucleotide encoding a PERM1 protein comprises SEQ ID NO: 2, 4, 12, or a nucleic acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with SEQ ID NO: 2, 4 or 12. In specific embodiments, the PERM1 protein of the subject invention is encoded by a polynucleotide comprising SEQ ID NO: 2, 4, 12, or a nucleic acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with SEQ ID NO: 2, 4 or 12. In specific embodiments, the PERM1 protein of the subject invention comprises the amino acid sequence of SEQ ID NO: 3, 5, 6, 7 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with SEQ ID NO: 3, 5, 6, or 7. In specific embodiments, the polynucleotide of the subject invention also includes a polynucleotide that encodes the amino acid sequence of SEQ ID NO: 3, 5, 6, 7 or an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with SEQ ID NO: 3, 5, 6, or 7. In certain embodiments, PERM1 variants or fragments may comprise one or more substitution of amino acids including natural or non-natural amino acids. For example, natural or non-natural amino acids can be substituted for the amino acids of a polypeptide, so long as the polypeptide having the substituted amino acids retains substantially the same biological or functional activity as the polypeptide in which amino acids have not been substituted. Examples of non-natural amino acids include, but are not limited to, ornithine, citrulline, hydroxyproline, homoserine, phenylglycine, taurine, iodotyrosine, 2,4-diaminobutyric acid, α- amino isobutyric acid, 4-aminobutyric acid, 2-amino butyric acid, γ-amino butyric acid, ε-amino hexanoic acid, 6-amino hexanoic acid, 2-amino isobutyric acid, 3-amino propionic acid, norleucine, norvaline, sarcosine, homocitrulline, cysteic acid, τ-butylglycine, τ-butylalanine, phenylglycine, cyclohexylalanine, β-alanine, fluoro-amino acids, designer amino acids such as β- methyl amino acids, C-methyl amino acids, N-methyl amino acids, and amino acid analogues in general. Non-natural amino acids also include amino acids having derivatized side groups. Furthermore, any of the amino acids in the protein can be of the D (dextrorotary) form or L (levorotary) form. Allelic variants of a protein sequence of a wild-type polypeptide are also encompassed within the scope of the invention. The subject invention also concerns variants of the polynucleotides of the present invention that encode functional polypeptides of the invention. Variant sequences include those sequences wherein one or more nucleotides of the sequence have been substituted, deleted, and / or inserted. The nucleotides that can be substituted for natural nucleotides of DNA have a base moiety that can include, but is not limited to, inosine, 5-fluorouracil, 5-bromouracil, hypoxanthine, 1-methylguanine, 5-methylcytosine, and tritylated bases. The sugar moiety of the nucleotide in a sequence can also be modified and includes, but is not limited to, arabinose, xylulose, and hexose. In addition, the adenine, cytosine, guanine, thymine, and uracil bases of the nucleotides can be modified with acetyl, methyl, and / or thio groups. Sequences containing nucleotide substitutions, deletions, and / or insertions can be prepared and tested using standard techniques known in the art. Fragments and variants of a polypeptide or PERM1 of the present invention can be generated and tested for the presence of biological function using standard techniques known in the art. Thus, an ordinarily skilled artisan can readily prepare and test fragments and variants of a polypeptide of the invention and determine whether the fragment or variant retains functional or biological activity relative to full-length or a non-variant polypeptide. In specific embodiments, the PERM1 protein synthesized from the expression construct in cells is tagged with a FLAG octapeptide (DYKDDDDK, SEQ ID NO: 1) at the C-terminal. This modified PERM1 protein is preferentially retained in the cytosol and interacts with contractile proteins, such as Troponin C, which enhances PERM1’s ability to improve muscle contractility in the heart. Polynucleotides and polypeptides contemplated within the scope of the subject invention can also be defined in terms of more particular identity and / or similarity ranges with those sequences of the invention specifically exemplified herein. The sequence identity will typically be greater than 60%, preferably greater than 75%, more preferably greater than 80%, even more preferably greater than 90%, and can be greater than 95%. The identity and / or similarity of a sequence can be 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99% as compared to a sequence exemplified herein. As used herein, the terms “nucleic acid” and “polynucleotide” refer to a deoxyribonucleotide, ribonucleotide, or a mixed deoxyribonucleotide and ribonucleotide polymer in either single- or double-stranded form, and unless otherwise limited, would encompass known analogs of natural nucleotides that can function in a similar manner as naturally-occurring nucleotides. The polynucleotide sequences include the DNA strand sequence that is transcribed into RNA and the strand sequence that is complementary to the DNA strand that is transcribed. The polynucleotide sequences also include both full-length sequences as well as shorter sequences derived from the full-length sequences. Allelic variations of the exemplified sequences also fall within the scope of the subject invention. The polynucleotide sequence includes both the sense and antisense strands either as individual strands or in the duplex. In one embodiment, the subject invention provides the use of gene therapy for production of a therapeutic protein to treat cardiovascular diseases or disorders. In preferred embodiments, the therapeutic strategy is based on transducing or transfecting cells of, for example, hearts, skeletal muscles, and subcutaneous adipose tissue with a gene therapy (e.g., adeno-associated virus (AAV) gene therapy) vector comprising a transgene of interest to promote expression of the transgene of interest. In a specific embodiment, the gene therapy is an AAV-based gene therapy. Advantageously, the method of the subject invention does not rely on a specific AAV serotype, which has a clinical and commercial advantage that facilitates the use of an array of AAV serotypes to overcome the effects of immunoresistance, allowing for increasing patient eligibility and reapplication of the therapy. Recombinant AAVs (rAAVs) are well suited for treating disorders because they stably transfect cells to support the continuous production of the encoded protein. As used herein, “gene therapy” is the insertion of a nucleic acid sequence (e.g., a transgene) into an individual’s cells and / or tissues to treat a disease. For example, the transgene can be a functional mutant allele that replaces or supplements a defective one. Gene therapies also include insertion of a transgene that increases, or decreases expression, activity or function of an endogenous gene or protein. Such transgenes may be exogenous. An exogenous molecule or sequence is understood to be molecule or sequence not normally occurring in the cell, tissue and / or individual to be treated. An AAV gene therapy vector thus refers to an AAV vector for use in gene therapy. The term “transgene” is used to refer to a non-native nucleic acid with respect to the AAV nucleic acid sequence. It is used to refer to a polynucleotide that can be introduced into a cell or organism. Transgenes include any polynucleotide, such as a gene that encodes a polypeptide or protein, or a polynucleotide that is not transcribed (e.g., lacks an expression control element, such as a promoter that drives transcription). A transgene is preferably inserted between inverted terminal repeat (ITR) sequences. In accordance with the subject invention, PERM1 regulates cardiac contractility, which involves binding of PERM1 to Troponin C (TnC), an essential regulator of contractile force, and an increase in TnC protein expression. Importantly, adeno-associated virus (AAV)-mediated gene delivery of Perm1 simultaneously promotes cardiac contractility and mitochondrial biogenesis. Advantageously, gene delivery of Perm1 can serve as a new therapeutic approach to treat heart failure patients, in particular, HFrEF patients and reduce the mortality rate of heart failure. In one embodiment, the subject invention provides an AAV gene therapy vector comprising a transgene of interest. The transgene may be naturally occurring, e.g., wild-type, or it may be recombinant. The transgene may also be modified compared to the wild-type. The transgene is typically included in the gene therapy vector as a cDNA sequence. As used herein, an “AAV vector,” or “AAV gene therapy vector” refers to a recombinant AAV vector (or “rAAV vector”) that is derived from the wild type AAV by using molecular methods. An AAV vector is distinguished from a wild type (wt) AAV vector because at least a part of the viral genome has been replaced with a transgene, which is a non-native nucleic acid with respect to the wild-type AAV nucleic acid sequence. Preferably, a gene product of interest is flanked by AAV ITRs on either side. Any AAV ITR may be used in the constructs of the invention, including ITRs from AAV1, AAV2, AAV4, AAV5, AAV6, AAV8, and / or AAV9. The term “adeno-associated virus” (AAV) in the context of the present invention includes without limitation AAV type 1, AAV type 2, AAV type 3 (including types 3A and 3B), AAV type 4, AAV type 5, AAV type 6, AAV type 7, AAV type 8, AAV type 9, AAV type 10, AAV type 11, avian AAV, bovine AAV, canine AAV, equine AAV, and ovine AAV and any other AAV now known or later discovered. A number of additional AAV serotypes and clades have been identified (see, e.g., Gao et al., (2004) J. Virol. 78:6381-6388), which are also encompassed by the term “AAV.” In specific embodiments, the AAV vector is selected from AAV serotypes 1, 2, 3B, 4, 5, 6, 8, and 9. In preferred embodiments, the AAV vector is AAV serotype 8 or 9. The genomic sequences of various AAV and autonomous parvoviruses, as well as the sequences of the ITRs, Rep proteins, and capsid subunits are known in the art. Such sequences may be found in the literature or in public databases such as the GenBank® database. See, e.g., GenBank® Accession Numbers NC 002077, NC 001401, NC 001729, NC 001863, NC 001829, NC 001862, NC 000883, NC 001701, NC 001510, AF063497, U89790, AF043303, AF028705, AF028704, J02275, J01901, J02275, X01457, AF288061, AH009962, AY028226, AY028223, NC 001358, NC 001540, AF513851, AF513852, AY530579, AY631965, and AY631966. In certain embodiments, the AAV gene therapy vector further comprises one or more of signal peptide sequences, promoters, enhancers, and terminators. In specific embodiments, the promoter may be selected from, for example, constitutive promoters, and cell / tissue / organ-specific promoters. For example, the constitutive promoter can be CMV, CAG, or Ua1, and the cell / tissue / organ-specific promoter can be a tissue-specific promoter such as a heart -specific promoter. In a specific embodiment, the promoter is a CMV promoter, and the terminator is bovine growth hormone polyadenylation signal (BGH polyA) or human growth hormone polyadenylation signal (hGH polyA). In specific embodiments, the transgene of interest comprises a polynucleotide that encodes a PERM1 protein as described in the subject invention or a peptide having an amino acid sequence sharing at least 75%, 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99%, or 99.9% identity with a PERM1 protein. In specific embodiments, the transgene of interest comprises a polynucleotide having at least 75%, 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99%, or 99.9% identity with a nucleic acid sequence that encodes a PERM1 protein as described in the subject invention or a peptide having an amino acid sequence sharing at least 75%, 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99%, or 99.9% identity with a PERM1 protein. In certain embodiments, the gene therapy vector comprises: (1) a polynucleotide comprising SEQ ID NO: 2, 4, or 12; (2) a nucleic acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with SEQ ID NO: 2, 4 or 12; (3) a polynucleotide that encodes the amino acid sequence of SEQ ID NO: 3, 5, 6, or 7; or (4) a polynucleotide that encodes an amino acid sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with SEQ ID NO: 3, 5, 6, or 7. In certain embodiments, the AAV gene therapy vector comprises: i) a promoter such as CMV or CBh; ii) a polynucleotide sequence encoding a PERM1 protein, a polynucleotide sequence having at least 75%, 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99%, or 99.9% identity with the polynucleotide sequence encoding a PERM1 protein, or a polynucleotide sequence encoding a peptide having an amino acid sequence sharing at least 75%, 80%, 85%, 90%, 92%, 95%, 97%, 98%, 99%, or 99.9% identity with a PERM1 protein; iii) a terminator such as BGH polyA or hGH polyA; and iv) optionally, ITR sequences at the 3’ and 5’ ends. In a specific embodiment, the AAV gene therapy vector comprises SEQ ID NOs: 8 and / or 9. In certain embodiments, the AAV gene therapy vector comprises a promoter such as CMV or CBh; a polynucleotide sequence comprising SEQ ID NO: 12; a terminator such as BGH polyA or hGH polyA; and optionally, ITR sequences at the 3’ and 5’ ends. In specific embodiments, the subject invention provides the use of a AAV gene therapy for in situ production of a PERM1 protein to treat diseases or disorders. It is understood that the AAV vectors, or AAV gene therapy vectors, according to the subject invention, encompass a vector genome having a gene of interest. Thus, the AAV vectors according to the subject invention are delivery vehicles that are to deliver their payload, a vector genome having a transgene, e.g., a transgene that is to be of benefit to the subject (e.g., human), to their target cells. AAV vectors can be used in a medical treatment of a subject, e.g., a human patient suffering from a disease, which may be ameliorated due to the delivery of the transgene. In one embodiment, the subject invention provides a composition comprising a polynucleotide, gene therapy vector and / or PERM1 protein of the subject invention. In vivo administration of the subject polynucleotides, gene therapy vector, proteins and compositions containing them, can be accomplished by any suitable method and technique presently or prospectively known to those skilled in the art. The subject polynucleotides, gene therapy vector, and / or proteins can be formulated in a physiologically or pharmaceutically acceptable form and administered by any suitable route known in the art including, for example, oral, nasal, transdermal, and parenteral routes of administration. As used herein, the term parenteral includes subcutaneous, intradermal, intravenous, intravascular, intramuscular, intraperitoneal, and intrasternal administration, such as by injection. Administration of the subject polynucleotides, gene therapy vector, proteins or composition comprising the polynucleotides, gene therapy vector, or proteins of the invention can be a single administration, or at continuous or distinct intervals as can be readily determined by a person skilled in the art. The polynucleotide, gene therapy vector and / or protein of the subject invention, and compositions comprising them, can also be administered utilizing liposome and nanotechnology, exosomes, slow-release capsules, implantable pumps, and biodegradable containers, and orally or intestinally administered intact cells expressing the therapeutic product. These delivery methods can, advantageously, provide a uniform dosage over an extended period of time. The polynucleotide, gene therapy vector and / or protein of the subject invention can be formulated according to known methods for preparing physiologically acceptable compositions. In general, the compositions of the subject invention will be formulated such that an effective amount of the compound is combined with a suitable carrier in order to facilitate effective administration of the composition. The compositions used in the present methods can also be in a variety of forms. These include, for example, solid, semi-solid, and liquid dosage forms, such as tablets, pills, powders, liquid solutions or suspension, suppositories, injectable and infusible solutions, and sprays. The preferred form depends on the intended mode of administration and therapeutic application. The compositions also preferably include conventional physiologically acceptable carriers and diluents which are known to those skilled in the art. Examples of carriers or diluents for use with the subject compounds include ethanol, dimethyl sulfoxide, glycerol, alumina, starch, saline, and equivalent carriers and diluents. To provide for the administration of such dosages for the desired therapeutic treatment, compositions of the invention will advantageously comprise between about 0.1% and 99%, and especially, 1 and 15% by weight of the total of one or more of the subject compounds based on the weight of the total composition including carrier or diluent. The tablets, troches, pills, capsules, and the like may also contain the following: binders such as gum tragacanth, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, fructose, lactose or aspartame or a flavoring agent such as peppermint, oil of wintergreen, or cherry flavoring may be added. When the unit dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be present as coatings or to otherwise modify the physical form of the solid unit dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac, or sugar and the like. A syrup or elixir may contain the active compound, sucrose or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring such as cherry or orange flavor. Of course, any material used in preparing any unit dosage form should be pharmaceutically acceptable and substantially non-toxic in the amounts employed. In addition, the active compound may be incorporated into sustained-release preparations and devices. The polynucleotide, gene therapy vector, protein and compositions of the invention, including pharmaceutically acceptable salts or analogs thereof, can be administered intravenously, intravascularly, intramuscularly, or intraperitoneally by infusion or injection. Solutions of the active agent or its salts can be prepared in water, optionally mixed with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, triacetin, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations can contain a preservative to prevent the growth of microorganisms. The pharmaceutical dosage forms suitable for injection or infusion can include sterile aqueous solutions or dispersions or sterile powders comprising the active ingredient which are adapted for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions, optionally encapsulated in liposomes. The ultimate dosage form should be sterile, fluid and stable under the conditions of manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid dispersion medium comprising, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the formation of liposomes, by the maintenance of the required particle size in the case of dispersions or by the use of surfactants. Optionally, the prevention of the action of microorganisms can be brought about by various other antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, buffers or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the inclusion of agents that delay absorption, for example, aluminum monostearate and gelatin. Sterile injectable solutions may be prepared by incorporating a compound and / or agent of the invention in the required amount in the appropriate solvent with various other ingredients enumerated above, as required, followed by filter sterilization. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying techniques, which yield a powder of the active ingredient plus any additional desired ingredient present in the previously sterile-filtered solutions. The present invention also provides pharmaceutical compositions comprising a polynucleotide, gene therapy vector and / or protein of the invention in combination with a pharmaceutically acceptable carrier. Pharmaceutical compositions adapted for oral, topical or parenteral administration, comprising an amount of a compound constitute a preferred embodiment of the invention. The dose administered to a patient, particularly a human, in the context of the present invention should be sufficient to achieve a therapeutic response in the patient over a reasonable time frame, without lethal toxicity, and preferably causing no more than an acceptable level of side effects or morbidity. One skilled in the art will recognize that dosage will depend upon a variety of factors including the condition (health) of the subject, the body weight of the subject, kind of concurrent treatment, if any, frequency of treatment, therapeutic ratio, as well as the severity and stage of the pathological condition. To provide for the administration of such dosages for the desired therapeutic treatment, in some embodiments, pharmaceutical compositions of the invention can comprise between about 0.1% and 45%, and especially, 1 and 15%, by weight of the total of one or more of the compounds based on the weight of the total composition including carrier or diluents. Illustratively, dosage levels of the administered active ingredients can be: intravenous, 0.01 to about 20 mg / kg; intravascular, 0.01 to about 20 mg / kg; intraperitoneal, 0.01 to about 100 mg / kg; subcutaneous, 0.01 to about 100 mg / kg; intramuscular, 0.01 to about 100 mg / kg; orally 0.01 to about 200 mg / kg, and preferably about 1 to 100 mg / kg; intranasal instillation, 0.01 to about 20 mg / kg; and aerosol, 0.01 to about 20 mg / kg of animal (body) weight. Mammalian species that benefit from the disclosed methods include, but are not limited to, primates, such as apes, chimpanzees, orangutans, humans, monkeys; domesticated animals (e.g., pets) such as dogs, cats, guinea pigs, hamsters, Vietnamese pot-bellied pigs, rabbits, and ferrets; domesticated farm animals such as cows, buffalo, bison, horses, donkey, swine, sheep, and goats; exotic animals typically found in zoos, such as bear, lions, tigers, panthers, elephants, hippopotamus, rhinoceros, giraffes, antelopes, sloth, gazelles, zebras, wildebeests, prairie dogs, koala bears, kangaroo, opossums, raccoons, pandas, hyena, seals, sea lions, elephant seals, otters, porpoises, dolphins, and whales. As used herein, the terms “patient” and “subject” are used interchangeably and are intended to include such human and non-human species. Likewise, in vitro methods of the present invention can be carried out on cultured cells or tissues of such human and non-human species. In one embodiment, the subject invention provides a method for treating or preventing a disease associated with impaired muscle contraction and mitochondrial function, the method comprising administering, to the subject in need thereof, an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition of the subject invention comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof. In one embodiment, the subject invention provides a method for treating or preventing a disease associated with impaired muscle contraction and mitochondrial function, the method comprising administering, to a subject in need thereof: (1) a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein; (2) a PERM1 protein or a variant or fragment thereof; or (3) an AAV gene therapy vector comprising a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein. In specific embodiments, the disease associated with impaired muscle contraction and mitochondrial function is a cardiovascular disease or aging-related disease. In a specific embodiment, the cardiovascular disease is heart failure (e.g., HFrEF) or cardiomyopathy (e.g., diabetic cardiomyopathy). In one embodiment, the subject invention provides a method for treating or preventing a cardiovascular disease or condition in a subject, the method comprising administering, to the subject in need thereof, an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition of the subject invention comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof. In one embodiment, the subject invention provides a method for treating or preventing heart failure in a subject, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the gene therapy vector, polynucleotide, PERM1 protein or a variant or fragment thereof and compositions of the subject invention can be delivered to a subject via any acceptable route including but not limited to, intravascular, intravenous, intraperitoneal, oral, mucosal, intramuscular, intradermal, subcutaneous, intraosseous, transdermal, inhalation, etc. In one embodiment, the subject invention provides a method for treating or preventing heart failure with reduced ejection fraction (HFrEF) in a subject, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the subject invention provides a method for reducing the risk of cardiovascular death and worsening heart failure in a subject with HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the subject invention provides a method for enhancing cardiac contractility in a subject, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In a specific embodiment, the subject has HFrEF. In one embodiment, the subject invention provides a method for enhancing cardiac contractility of a subject with heart failure, the method comprising administering to the subject one of the following: (1) a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a PERM1 protein; (2) a polynucleotide sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 99.9% identity with a nucleic acid sequence encoding a PERM1 protein; (3) PERM1 protein or a variant or fragment thereof; and (4) an AAV gene therapy vector comprising the polynucleotide of (1) or (2). In one embodiment, the subject invention provides a method for regulating cardiomyocyte length and volume in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In specific embodiments, the administration shortens the cardiomyocyte length and increases the cardiomyocyte volume. In certain embodiments, the method of the subject invention further comprises obtaining a heart tissue sample of the subject and determining cardiomyocyte length and volume. In certain embodiments, the subject invention provides a method for improving / enhancing / increasing the strength of cardiac muscle in a subject, preferably, a subject with HF (e.g., HFrEF), the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In certain embodiments, the subject invention provides a method for preventing a decline in the strength of cardiac muscle in a subject, preferably, a subject with HF (e.g., HFrEF), the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In one embodiment, the subject invention provides a method for increasing or enhancing EF in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In certain embodiments, the method of the subject invention further comprises assessing / measuring / determining systolic and diastolic left ventricular (LV) function, assessing / measuring / determining diastolic and systolic LV diameters, assessing / measuring / determining LV systolic wall thickness, assessing / measuring / determining LV ejection fraction (LVEF) and / or assessing / measuring / determining VO2max, an established indicator of cardiovascular fitness and aerobic endurance. In one embodiment, the subject invention provides a method for increasing the expression of TnC and / or PGC-1α in the heart of a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the subject invention provides a method for increasing / enhancing the binding of PERM1 to TnC in the heart of a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the subject invention provides a method for promoting mitochondrial biogenesis in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the subject invention provides a method for preventing a decline in mitochondrial biogenesis in a subject, preferably, a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In certain embodiments, the method comprises assessing mitochondrial bioenergetics, and / or determining the ability of the heart to withstand pathological stress by assessing mitochondrial DNA copy number before and / or after the administration step. In certain embodiments, the subject invention provides a method for improving / enhancing / increasing mitochondrial respiration in a subject, preferably, a subject with HF (e.g., HFrEF), the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In preferred embodiments, the method improves / enhances / increases mitochondrial respiration in the heart of a subject. In certain embodiments, the subject invention provides a method for improving / enhancing / increasing mitochondrial respiration in a cell, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the cell; or contacting the cell with an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention. In certain embodiments, the subject invention provides a method for preventing or reducing a decline in mitochondrial respiration in a subject, preferably, a subject with HF (e.g., HFrEF), the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In certain embodiments, the subject invention provides a method for preventing or reducing respiratory impairment in a subject, preferably, a subject with HF (e.g., HFrEF), the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In certain embodiments, the subject invention provides a method for preventing or reducing a decline in mitochondrial respiration in a cell, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the cell; or contacting the cell with an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention. Mitochondria are power plants of a living cell, which produce universal energy currency (ATP) by breaking down fats, sugars, and proteins. This process is mediated through an oxidative phosphorylation process that consumes oxygen. The purpose of respiration is to deliver oxygen to mitochondria, hence, the consumption of oxygen by mitochondria is termed “mitochondrial respiration.” In a specific embodiment, the cell is a cardiomyocyte. In a specific embodiment, the cell is obtained from a healthy subject or a subject with a disease or condition associated with respiratory impairment. In a specific embodiment, the cell is obtained from a subject with HF (e.g., HFrEF). In a specific embodiment, the cell is a cardiomyocyte from a subject with HF (e.g., HFrEF). In certain embodiments, the subject invention provides a method for treating or preventing pathological hypertrophy and / or fibrosis in a subject, preferably, a subject with HF (e.g., HFrEF), the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In certain embodiments, the method comprises assessing or evaluating symptoms of HFrEF, for example, an increased mass of heart muscle (hypertrophy) and increased deposition of collagen fibers in the extracellular matrix (fibrosis), before and / or after the administration step. In one embodiment, the subject invention provides a method for reducing the risk of hospitalization for heart failure and cardiovascular death in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof to the subject in need thereof. In one embodiment, the subject invention provides a method for treating or preventing heart failure with reduced ejection fraction (HFrEF) in a subject, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for reducing the risk of cardiovascular death and worsening heart failure in a subject with HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for enhancing cardiac contractility in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for regulating cardiomyocyte length and volume in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for increasing ejection fraction (EF) in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for increasing the expression of TnC and PGC-1α in the heart of a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for enhancing the binding of PERM1 to TnC in the heart of a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for promoting mitochondrial biogenesis in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In one embodiment, the subject invention provides a method for reducing the risk of hospitalization for heart failure and cardiovascular death in a subject with HF, specifically, HFrEF, the method comprising administering an effective amount of the AAV gene therapy vector of the subject invention or a composition comprising the AAV gene therapy vector to the subject in need thereof. In some embodiments, the method of the subject invention further comprises a step of detecting or measuring the expression of PERM1 and / or TnC in a heart sample from the subject. In certain embodiments, the method further comprises assessing / measuring / determining systolic and diastolic left ventricular (LV) function, assessing / measuring / determining diastolic and systolic LV diameters, assessing / measuring / determining LV systolic wall thickness and / or assessing / measuring / determining VO2max. In certain embodiments, the subject invention provides a method for treating or preventing excessive protein modification by the process of O-GlcNAcylation in a subject, preferably, a subject with HF, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the subject in need thereof. In certain embodiments, the subject invention provides a method for treating or preventing excessive protein modification by the process of O-GlcNAcylation in a cell, the method comprising administering an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention to the cell; or contacting the cell with an effective amount of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention. In specific embodiments, the method further comprises assessing / measuring / determining O-GlcNAcylation in a cell or tissue obtained from a subject. O-GlcNAcylation is a post- translational modification of proteins via attachment of a sugar N-acetylglucosamine (GlcNAc) to serine or threonine residues of a large number of proteins in living cells. This process acts as a nutrient sensor, linking cellular nutrient status to various cellular processes. As with many other regulatory mechanisms in cells, O-GlcNAcylation is necessary for normal cell function, but under various pathophysiological conditions including HFrEF, it becomes excessive and harmful. In certain embodiments, the PERM1 nucleic acid and / or protein can be delivered via exosomes, naturally occurring lipid membrane-enclosed vesicles. These vesicles carry various types of cellular cargo, including lipids, nucleic acids, and proteins, and can facilitate the targeted delivery of therapeutic molecules. Advantages of using exosomes for Perm1 delivery include their low immunogenicity, reducing the risk of an immune response, and their potential for cell-specific targeting, which can enhance delivery efficiency to the desired tissues or cells. In certain embodiments, the AAV gene therapy vector as described above is administered at a dosage corresponding with at least 1011capsids / kg of body weight. The AAV gene therapy vector is administered to a subject in a treatment in an amount effective to obtain, for example, a meaningful level of transgene expression and secretion into the blood. In certain embodiments, the AAV gene therapy vector is administered at a dosage corresponding with at least 2 x 1011capsids / kg of body weight, 5 x 1011capsids / kg of body weight, 1012capsids / kg of body weight, 2 x 1012capsids / kg of body weight, 5 x 1012capsids / kg of body weight, 1013capsids / kg of body weight, 2 x 1013capsids / kg of body weight, 5 x 1013capsids / kg of body weight, 1014capsids / kg of body weight, 2 x 1014capsids / kg of body weight, 5 x 1014capsids / kg of body weight, 1015capsids / kg of body weight, 2 x 1015capsids / kg of body weight, 5 x 1015capsids / kg of body weight, 1016capsids / kg of body weight, 2 x 1016capsids / kg of body weight, or 5 x 1016capsids / kg of body weight. In some embodiments, the AAV gene therapy vector is administered at a dosage from about 1010capsids / kg of body weight to about 1017capsids / kg of body weight, from about 1011capsids / kg of body weight to about 2 x 1016capsids / kg of body weight, from about 1012capsids / kg of body weight to about 1016capsids / kg of body weight, from about 1012capsids / kg of body weight to about 5 x 1015capsids / kg of body weight, from about 1012capsids / kg of body weight to about 1015capsids / kg of body weight, from about 1012capsids / kg of body weight to about 5 x 1014capsids / kg of body weight, from about 1012capsids / kg of body weight to about 1014capsids / kg of body weight, or from about 1012capsids / kg of body weight to about 5 x 1013capsids / kg of body weight. The dosage selected may also be based on genomic copies. Genomic copies mean the amount of vector genomes contained in the AAV preparation. The gc titer of an AAV vector preparation can easily be determined by using a qPCR that quantifies a vector genomic sequence. Specifically, the AAV gene therapy vector is used at a dosage corresponding with at least 1011gc / kg of body weight, at least 2×1011gc / kg of body weight, at least 5×1011gc / kg of body weight, at least 1012gc / kg of body weight, at least 2×1012gc / kg of body weight, at least 5×1012gc / kg of body weight, at least 1013gc / kg of body weight, at least 2×1013gc / kg of body weight, at least 5×1013gc / kg of body weight, at least 1014gc / kg of body weight, at least 2×1014gc / kg of body weight, at least 5×1014gc / kg of body weight, at least 1015gc / kg of body weight, at least 2×1015gc / kg of body weight, at least 5×1015gc / kg of body weight, or at least 1016gc / kg of body weight. In a preferred embodiment, the AAV gene therapy vector is used at a dosage from about 1011gc / kg of body weight to about 1017gc / kg of body weight, from about 2×1011gc / kg of body weight to about 1016gc / kg of body weight, from about 5×1011gc / kg of body weight to about 1015gc / kg of body weight, from about 1012gc / kg of body weight to about 5×1014gc / kg of body weight, from about 1012gc / kg of body weight to about 2×1014gc / kg of body weight, from about 1012gc / kg of body weight to about 1014gc / kg of body weight, from about 1012gc / kg of body weight to about 5×1013gc / kg of body weight, or from about 1012gc / kg of body weight to about 1013gc / kg of body weight. In a specific embodiment, the gene therapy vector or composition of the subject invention is administered to the subject for the transgene of interest to specifically express in the heart as a medical treatment. In certain embodiments, the subject has a left ventricular ejection fraction (LVEF) of at least less than or equal to 40%, 35%, 30%, 25%, or 20% of that of a normal healthy subject. LVEF may be determined, for instance, by the use of an echocardiogram, radionuclide ventriculogram, contrast angiography, or cardiac MRI. In specific embodiments, the subject has a symptom of, or has been diagnosed with, acute myocardial infarction and / or has a risk of developing HF. Advantageously, the treatment of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention treats or prevents HF in the subject. In a specific embodiment, the treatment is an AAV-Perm1 treatment of the subject invention. In a specific embodiment, the subject is undergoing implantation of a Left Ventricular Assist Device (LVAD). Advantageously, the treatment of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention increases the probability of cardiac recovery. In a specific embodiment, the treatment to the subject undergoing implantation of Left Ventricular Assist Device (LVAD) is an AAV-Perm1 treatment of the subject invention. In certain embodiments, the subject has been diagnosed with a cancer or tumor, and / or is undergoing an anticancer treatment (e.g., doxorubicin). Advantageously, the treatment of a gene therapy vector, a polynucleotide, a PERM1 protein or a variant or fragment thereof of the subject invention or a composition comprising the gene therapy vector, polynucleotide, or PERM1 protein or a variant or fragment thereof of the subject invention prevents HF as a side effect of cancer treatment in the subject. In a specific embodiment, the treatment to the subject undergoing an anticancer treatment is an AAV-Perm1 treatment of the subject invention. In a specific embodiment, the gene therapy vector used in the subject invention is AAV- Perm1 and AAV-Perm1-FLAG. In a specific embodiment, the polynucleotide used in the subject invention encodes a PERM1 protein or a modified PERM1 protein such as PERM1-FLAG. In a specific embodiment, the PERM1 protein or a variant or a fragment thereof is selected from PERM1 and PERM1-FLAG. In some embodiments, the methods of the subject invention result in at least one of the following outcomes: (1) extends the length of time to a first heart failure event, and / or a fatal cardiovascular event; (2) reduces worsening of heart failure symptoms; (3) decreases the number of heart failure events and / or reduces the incidence of a fatal cardiovascular event; (4) reduces the risk of hospitalization for heart failure and cardiovascular death; (5) reduces the risk of all-cause mortality; and (6) increases physical exercise endurance in heart failure patients. As used herein, the term “heart failure with reduced ejection fraction,” “HFrEF,” or “patient with HFrEF” refers to the chronic medical condition whereby a patient's left ventricular ejection fraction (LVEF) is ≤40% and the patient's heart failure symptoms fall within Stages II-IV of the New York Heart Association (NYHA) heart failure classification system. See, Dolgin M, “Criteria Committee of the New York Heart Association; Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels,” 9th ed., Boston, Mass.: Little Brown & Co (1994). In some embodiments, “patients with HFrEF” fall within Stage II of the NYHA HF classification. In some embodiments, “patients with HFrEF” fall within Stages III or IV of the NYHA HF classification. The NYHA HF classification system categorizes classes I through IV according to subjective patient symptom assessment and classifies heart failure based on a patient's ability to function in daily life: Class I: No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea; Class II. Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, and dyspnea; Class III. Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspnea. Class IV. Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases. As used herein, a “heart failure event” refers to a hospitalization for HF and / or an urgent HF medical visit. As used herein, a “hospitalization for HF” or an “HF hospitalization” refers to an admission to a hospital for at least 24 hours with a primary diagnosis of HF. In some embodiments, the hospitalized patient exhibits new or worsening symptoms due to HF on presentation. In some embodiments, the hospitalized patient has objective evidence of new or worsening HF. In some embodiments, the hospitalized patient receives initiation or intensification of treatment specifically for HF. In some embodiments, the hospitalized patient has all of the foregoing criterion. As used herein, “symptoms due to HF” include at least one symptom of dyspnea, decreased exercise tolerance, fatigue, or other symptoms of end-organ perfusion or volume overload. In some embodiments, the symptoms due to HF are new or worsened from a prior period of time, medical or hospital visit. As used herein, “cardiovascular (CV) death” refers to death of the patient undergoing treatment for HF, specifically, HFrEF, as described herein, due to, for example, acute myocardial infarction (MI), sudden cardiac death, heart failure or cardiogenic shock, stroke (cerebrovascular event), cardiovascular procedures, cardiovascular hemorrhage, or other cardiovascular causes. In one embodiment, the method of the subject invention improves heart failure symptoms. Specifically, the method of the subject invention improves the left ventricular ejection fraction (LVEF) of the subject up to at least less than 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% of that of a normal healthy subject. As used herein a “reduction” means a negative alteration, and an “increase” means a positive alteration, wherein the negative or positive alteration is at least 0.001%, 0.01%, 0.1%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%. The term “regulate” is meant to alter (increase or decrease). Such alterations are detected by standard methods known in the art such as those described herein. As used herein, the term “subject” refers to an animal, needing or desiring delivery of the benefits provided by a therapeutic agent. The animal may be for example, humans, pigs, horses, goats, cats, mice, rats, dogs, apes, fish, chimpanzees, orangutans, guinea pigs, hamsters, cows, sheep, birds, chickens, as well as any other vertebrate or invertebrate. These benefits can include, but are not limited to, the treatment of a health condition, disease, or disorder; prevention of a health condition, disease or disorder; immune health; enhancement of the function of an organ, tissue, or system in the body. The preferred subject in the context of this invention is a human. The subject can be of any age or stage of development, including infant, toddler, adolescent, teenager, adult, or senior. As used herein, the terms “therapeutically-effective amount,” “therapeutically-effective dose,” “effective amount,” and “effective dose” are used to refer to an amount or dose of a therapeutic agent or composition that, when administered to a subject, is capable of treating or improving a condition, disease, or disorder in a subject or that is capable of providing enhancement in health or function to an organ, tissue, or body system. In other words, when administered to a subject, the amount is “therapeutically effective.” The actual amount will vary depending on a number of factors including, but not limited to, the particular condition, disease, or disorder being treated or improved; the severity of the condition; the particular organ, tissue, or body system of which enhancement in health or function is desired; the weight, height, age, and health of the patient; and the route of administration. As used herein, “treatment” or “treating” (and grammatical variants of these terms), refers to an approach for obtaining beneficial or desired results including but not limited to therapeutic benefit. A therapeutic benefit is achieved with the eradication or amelioration of one or more of the physiological symptoms associated with the underlying condition such that an improvement is observed in the subject, notwithstanding that the subject may still be afflicted with the underlying condition. Also, the term “treatment” refers to eradicating, reducing, ameliorating, or reversing a sign or symptom of a health condition, disease, or disorder to any extent, and includes, but does not require, a complete cure of the condition, disease, or disorder. Treating can be curing, improving, or partially ameliorating a disorder. “Treatment” can also include improving or enhancing a condition or characteristic, for example, bringing the function of a particular system in the body to a heightened state of health or homeostasis. The term “prevention” or any grammatical variation thereof (e.g., prevent, preventing, etc.), as used herein, includes but is not limited to, at least the reduction of likelihood of the risk of (or susceptibility to) acquiring a disease or disorder (i.e., causing at least one of the clinical symptoms of the disease not to develop in a patient that may be exposed to or predisposed to the disease but does not yet experience or display symptoms of the disease). The term “prevention” may refer to avoiding, delaying, forestalling, or minimizing one or more unwanted features associated with a disease or disorder, and / or completely or almost completely preventing the development of a disease or disorder and its symptoms altogether. Prevention can further include, but does not require, absolute or complete prevention, meaning the disease or disorder may still develop at a later time and / or with a lesser severity than it would without preventative measures. “Pharmaceutically acceptable carrier” or “pharmaceutically acceptable excipient” includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic, and absorption delaying agents, and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in the therapeutic compositions of the invention is contemplated. Supplementary active ingredients can also be incorporated into the compositions. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and / or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” The transitional terms / phrases (and any grammatical variations thereof) “comprising,” “comprises,” and “comprise” can be used interchangeably; “consisting essentially of,” and “consists essentially of” can be used interchangeably; and “consisting,” and “consists” can be used interchangeably. When ranges are used herein, such as for dose ranges, combinations and subcombinations of ranges (e.g., subranges within the disclosed range), specific embodiments therein are intended to be explicitly included. The transitional term “comprising,” “comprises,” or “comprise” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. By contrast, the transitional phrase “consisting of” excludes any element, step, or ingredient not specified in the claim. The phrases “consisting” or “consists essentially of” indicate that the claim encompasses embodiments containing the specified materials or steps and those that do not materially affect the basic and novel characteristic(s) of the claim. Use of the term “comprising” contemplates other embodiments that “consist” or “consisting essentially of” the recited component(s). The term “about” or “approximately” means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, “about” can mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, “about” can mean a range of up to 0-20%, 0 to 10%, 0 to 5%, or up to 1% of a given value. Alternatively, particularly with respect to biological systems or processes, the term can mean within an order of magnitude, preferably within 5-fold, and more preferably within 2-fold, of a value. Where particular values are described in the application and claims, unless otherwise stated the term “about” meaning within an acceptable error range for the particular value should be assumed. In the context of compositions containing amounts of concentrations of ingredients where the term “about” is used, these values include a variation (error range) of 0-10% around the value (X±10%). In the present disclosure, ranges are stated in shorthand to avoid having to set out at length and describe each and every value within the range. Any appropriate value within the range can be selected, where appropriate, as the upper value, lower value, or the terminus of the range. For example, a range of 0.1-1.0 represents the terminal values of 0.1 and 1.0, as well as the intermediate values of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and all intermediate ranges encompassed within 0.1-1.0, such as 0.2-0.5, 0.2-0.8, 0.7-1.0, etc. Values having at least two significant digits within a range are envisioned, for example, a range of 5-10 indicates all the values between 5.0 and 10.0 as well as between 5.00 and 10.00 including the terminal values. When ranges are used herein, combinations and subcombinations of ranges (e.g., subranges within the disclosed range) and specific embodiments therein are explicitly included. Unless otherwise defined, all terms of art, notations and other scientific terms or terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and / or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and / or as otherwise defined herein. EXAMPLES Methods Animals and tissue harvest All animal experiments were approved by the Institutional Animal Care and Use Committee (protocol #21-127) at Fralin Biomedical Research Institute (FBRI) at Virginia Tech. Animal pain and distress were always minimized with appropriate anesthetics. Wildtype mice of both sexes on C57BL / 6N background were injected with AAV vectors at the age of 8-12 weeks. Hearts, skeletal muscles, and subcutaneous adipose tissue were harvested from these animals 4 weeks after AAV injection and were immediately frozen in liquid nitrogen and stored at −80 °C until they were used for analysis. Additionally, animals were subjected to TAC surgery 4 weeks after AAV injection. Hearts were harvested from these animals 8 weeks post-TAC surgery and were immediately frozen in liquid nitrogen and stored at −80 °C until they were used for analysis. AAV generation and administration in mice The AAV9 vectors bearing the CMV promoter driving the expression of mouse PERM1 (AAV9.CMV.mPerm1-FLAG.hGH; SEQ ID NOs: 8 and 9) and eGFP (AAV9.CMV.PI.EGFP.WPRE.Bgh; SEQ ID NOs: 10 and 11) were generated at the Penn Vector Core at University of Pennsylvania (RRID: SCR_022432). AAV-Perm1 and AAV-GFP vectors were injected retro-orbitally at a dose of 1012genome copies per mouse. Transverse Aortic Constriction (TAC) Surgery Transverse aortic constriction was performed on mice after 4 weeks of AAV-injection. Briefly, mice were anesthetized with isoflurane (2% in O2) and surgery was performed. A single dose of Ethiqa (buprenorphine sustained release) (0.15 mg / kg) was administered subcutaneously before surgery. Mice were placed in a supine position and an incision of about 0.5cm length was made along the neck to expose aortic arch overlaying the trachea. The aortic arch was visualized under a low-powered microscope and a titanium micro clip (Horizon) was placed at the aortic arch between the innominate artery and the left common carotid artery using a ligation clip applicator that was calibrated to the diameter of 32-gauge size needle. Mice were sacrificed 8 weeks after TAC surgery to collect heart tissue. Control mice were subjected to sham procedure, in which all she steps of the standard surgical procedure were performed except application of the micro clip. Trichrome staining The mouse hearts were embedded in the optimal cutting temperature (OCT) and cut into 10 μm sections. The sections were stained with Masson's trichrome stain to evaluate cardiac fibrosis and imaged in the transmitted light at 10X magnification. The blue-green area occupied by collagen fibers in the interstitial space were measured using Image J software and presented as a percent of the total area. Western blotting analysis Samples for Western blotting analysis was prepared and analyzed as previously described (Oka et al., Front Cardiovasc Med 9 (2022) 1033457). Briefly, tissue samples were lysed in lysis buffer containing 50 mM Tris (pH 7.4), 10 mM EDTA, 1% sodium dodecyl sulphate (SDS), and protease inhibitors that include sodium butyrate (NaB), phenylmethyl sulphonyl fluoride (PMSF), sodium vanadate (Na3VO4), sodium fluoride (NaF) and EDTA-free protease inhibitor cocktail tablet. The lysate was centrifuged at 13,000 g for 10 min at 4°C and the supernatant was subjected to SDS electrophoresis followed by western blotting using 0.2 µm nitrocellulose membrane (Bio- Rad#1620112). The protein levels of PERM1, PGC-1α, TFAM, PGC-1β, ERRα, PPARα, NRF1, NRF2, Cytc, ATPsynthaseβ, CPT1b, CPT2, MCAD, GLUT4, OGT, OGA, OPA1, MFT1 and Troponin C were detected using rabbit antibodies (Sigma #HPA031711, Abcam #ab191838, Abcam #ab307302, Abcam #ab176328, Abcam #ab76228, Cayman product code #101710, Cell Signaling #D9K6P, Cell Signaling #D129C, Abcam #ab110325, Abcam #ab14730, Cell Signaling #E6M5M, Cell Signaling #E7D4W, Abcam #ab92461, Abcam #ab33780, Cell Signaling #24083, Abcam #ab124807, Abcam #ab56889-100, Novus Biologicals #NBP2-34206, and Abcam #ab137130) with 1:1000 dilution followed by goat anti-rabbit secondary antibody (Jackson ImmunoResearch Laboratories, Inc. #711- 035-152) with 1:5000 dilution. The values of band intensities were normalized using ^-tubulin (Abcam, #ab6046). The protein levels of total O- GlcNAcylated proteins and GLUT1 were detected using mouse antibodies (RL2, Abcam #ab2739 and Santa Cruz Biotechnology #sc377228) with 1:1000 dilution followed by anti-mouse secondary antibody from Abcam #ab6728 with 1:5000 dilution. The protein expression levels of ^-tubulin were consistent in all groups that were used in this study. For the quantification of O-GlcNAc blots, the blots were divided into two portions: bands ≥75 kDa (High molecular weight referred as "HMW") and bands <75 kDa (Low molecular weight referred to as "LMW"). In the HMW portion, non-specific bands around 75 kDa, which resulted from IgG band staining, were excluded by reimmunoblotting the same samples using anti-O-GlcNAc antibody pre-incubated overnight with 50 mM of an O-GlcNAc specific sugar, N-acetylglucosamine. Both HMW and LMW bands were quantified separately. Echocardiography Mice were subjected to echocardiography before AAV injection, 4 weeks after AAV injection, and 4 and 8 weeks after TAC. Echocardiographic analysis was performed using Vevo 2100 (Visual Sonics). Mice were induced at 4% isoflurane in 100% O2(at 2 L / min) and were maintained at 1.5 - 2.5% isoflurane (at 0.8 L / min). Throughout the imaging, heart rate was maintained between 450 and 550 bpm or 450±50 beats per minute, core body temperature between 36 and 38oC, and respiration rate between 30 and 100 per minute. In all mice PSAX M-mode and 4-chamber Power Doppler mode were used to assess systolic and diastolic left ventricular (LV) function, respectively. The full set of documented parameters is presented in Table 1. Table 1. Summary of all computed echocardiographic parameters. • p-value by Holm-Sidak's post-hoc multiple comparisons test performed after Repeated Measures ANOVA using Prism Ver. 10.2.3 (GraphPad Software LLC, Boston, MA}. EF: ejection fraction, FS: fractional shortening, LV: left ventricle, LVAW: left ventricular anterior wall; LVPW: left ventricular posterior wall; E / A ratio: the ratio of peak velocity of the blood flow caused by LV relaxation in early diastole (the E wave} to peak velocity flow caused by atrial contraction in late diastole (the A wave); NS: not significant. Exercise capacity test The exercise capacity test was conducted in mice injected with either AAV-GFP or AAV- Perm1 8 weeks after the AAV injection using method previously described (Guan et al., J Appl Physiol (1985). 2024 Jun 20. doi: 10.1152 / japplphysiol.00742.2023.). Briefly, mice were acclimatized to treadmill running on the Oxymax Metabolic Treadmill System (Columbus Instrument, OH, USA) in the morning for 10 min at a speed of 10 m / min at 0% grade for 3 consecutive days. On the day of the test, mice ran on the treadmill for 15 min at 5 m / min, 5% grade to acclimatize. Starting at minute 15, the treadmill speed increases for 3 m / min every 5 min at a 5% grade until exhaustion. An electric shock grid at the back of the treadmill set at 0.5 Amp, 1 Hz was used to stimulate running. The full set of documented parameters is presented in Table 2. Table 2. Summary of Exercise Capacity Test parameters. *p-value by non-parametric Mann-Whitney test using Prism Ver.10.2.3 (GraphPad Software LLC, Boston, MA). VO2max: the maximum rate of oxygen consumption; VCO2: the rate of CO2production; RER: Respiratory exchange ratio; AT: anaerobic threshold; Crossover: fatty acid to carbohydrate metabolism crossover time. Data is presented as mean ^ standard deviation. Histology 10 µm-thick sections of mid-LV were stained with Mason Trichrome stain to assess the percent of total area occupied by connective tissue using ImageJ software. In ImageJ, the following procedure was followed: 1) Use Image -> Adjust -> Color Threshold. Color filter settings: Red: 0-142; Green: 0-255; Blue:101-255. 2) Use Image -> Type -> 8-bit 3) Use Process -> Binary. Apply dilation 3 times; apply erosion 2 times 4) Use Analyze -> Analyze Particles. Configuration: size (in pixel^2): 25-infinity; circularity: 0-0.5 Cardiomyocyte volume analysis The entire protocol was based principally on using WGA- conjugated fluorophore to stain cell membranes and using Watershed algorithm for 3D segmentation of cardiomyocytes. To determine cardiomyocyte volume and shape, about 1-mm thick slabs of heart tissue were harvested from mid-section of the heart, incubated in 30% sucrose solution for 2 hours, embedded in the optimal cutting temperature (OCT) compound and stored at -80oC for subsequent processing. 100 µm-thick sections of mid-LV were cut perpendicular to the long axis of the heart using cryotome at -21oC. The cryosections were rinsed 3 times in PBS and fixed in 4% paraformaldehyde (PFA) in cold room for at least 2 hours. After that, the sections were incubated with Wheat Germ Agglutinin (WGA), Alexa Fluor 647 Conjugate (Life Technologies Corporation # W32466), at a concentration of 40 µg / mL in PBS for at least 6 hours in room temperature and mounted in Fluoromount-G (Electron Microscopy Science, Hatfield, PA, USA, #17984-25) for imaging. The slides were imaged using upright Nikon A1R scanning confocal microscope and 40x glycerol-immersion lens (numerical aperture 1.3). First, a tiled 2D image of the entire cross-section of the ventricles was obtained. From this image we selected a region of the anterior LV wall with the predominant fiber direction parallel to the plane of the section. From this region, 3D stacks were obtained at the size of 1024*1024*300 voxels and a voxel size of 0.2*0.2*0.2 µm. To reduce depth-dependent attenuation of the fluorescent signal, a linear increase in laser power along the Z- axis (intensity correction) was used. Excluding some optical sections at the top and the bottom surface, the final tissue volume used in analysis was 204*204*100 µm. Image processing, 3D segmentation and quantification was performed using ImageJ. The following procedure was followed: 1) Install MorpholibJ plug-in. 2) Use Adjust -> Bleach Correction. Choose Histrogram Matching option. 3) Use Plugins -> MorpholibJ -> Segmentation -> Morphological Segmentation. Set Tolerance to 120. 4) Use Plugins -> MorpholibJ -> Filter -> Kill Borders 5) Use Plugins -> MorpholibJ -> Analysis 6) Save the analysis table listing all morphological parameters for each segmented cell as a CSV file, apply cutoff criteria for cell volume (3,000 – 125,000 µm3) and the cell largest dimension (length)(60-175 µm). 7) Use Prism (GraphPad Software) to compute cumulative frequency distribution histograms for cell volume and length. Apply Kolmogorov–Smirnov test to determine if the frequency distributions are significantly different between AAV-GFP and AAV-Perm1 mice. Co-immunoprecipitation (Co-IP) Freshly harvested heart tissue samples from AAV-GFP and AAV-Perm1 mice were lysed in lysis buffer containing 0.5% Triton, 150 mM NaCl, 50 mM Tris-HCl, 1 mM NaF, 0.1 mM Na3VO4, 1 mM dithiothreitol (DTT), 1 mM EDTA, 1 mM ethylene glycol tetraacetic acid (EGTA), and EDTA-free protease inhibitor cocktail tablet. Lysate (750 µg - 1 mg) was incubated with 2 µg of either anti-FLAG antibody (RL2, Abcam #ab2739) or anti-IgG antibody (control, R&D systems #MAB002) overnight in a rotator for immunoprecipitation. It was followed by incubation with protein-G Sepharose beads for 1 hr 30 min in a rotator and centrifugation at 10,000 rpm for 2 min. The supernatant was aspirated, and the pellet was washed 4 times with lysis buffer. Sample buffer (Bio-Rad #1610737 with 2-mercaptoethanol [Bio-Rad#1610710],10 µl) was added to the washed pellet and spun down. The supernatant that was used for immunoblotting. Anti-PERM1 (Sigma #HPA031711) and Troponin C (Abcam #ab137130) were used as a primary antibody for immunoblotting. Gene expression analysis Real-time quantitative PCR (qPCR) was performed using Taqman primers as previously described (Oka et al., Front Cardiovasc Med 9 (2022) 1033457). Briefly, RNA was extracted using TRizol (Life Technologies), followed by ethanol extraction. Reverse transcription was performed from 1µg of RNA using QuantiTect Reverse Transcription Kit according to the manufacturer’s instruction (Qiagen #205313). Taqman primers were purchased from ThermoFisher as follows: Nppa: Mm01255747_g1, Col3a1: Mm00802300_m1, Col5a2: Mm00483675_m1). The Cq values from the genes were normalized using Rpl32 (Mm07306626_gH). Mitochondrial Isolation Cardiac muscle (~50-75mg) was separated for collection of a mitochondria-enriched fraction and placed immediately in 1mL of chilled mitochondria isolation buffer (MIB) [BSA (2mg / mL), Sucrose (70mM), Mannitol (210mM), HEPES (5mM), EGTA (1mM), pH 7.1]. At 4oC, muscle was processed with a saw-tooth homogenizer for ~45 seconds. Homogenate underwent two centrifugations for 10 minutes at 4oC at 800xg, then 9000xg. Following the second spin the cytosolic fraction was collected from the supernatant and immediately frozen at -80oC. The final pellet was cleared of MIB by vacuum and resuspended in MIB free from BSA to be quantified by the Bradford method for normalization of protein loading for mitochondrial assays. Mitochondrial Respiratory Flux (JO2): Conceptual: Mitochondrial respiration was assessed using the creatine kinase clamp method for two separate substrate conditions: (1) malate / pyruvate (M / P) and (2) malate / octanoylcarnitine (M / Oct). This method employs creatine kinase (CK) to maintain the stoichiometric ratio of ATP:ADP in a range that reflects in vivo conditions, increasing the physiological relevance of the findings above traditional experiments that utilize a supraphysiological bolus of ADP to assess maximal respiration. Further, this method allows for calculation of conductance by titration of phosphocreatine (PCr), which reflects a tractable bioenergetic stress test mimicking the transition from lower demand (ΔGATP) to higher demand. Calculations of ΔGATPwere performed using a freely available github calculator provided here (dmpio.github.io / bioenergetic-calculators / ck_clamp / ) with conditions of 37oC, 170 mM ionic strength, 5 mM creatine, 10 mM phosphate, and pH 7.1 based on parameters referenced here (github.com / dmpio / bioenergetic-calculators / blob / master / jupyter_notebook / creatine- kinaseclamp.ipynb). Ranges of conductance included ΔGATP-12.94 kCal / mol for maximal respiration, -13.38, -13.71, -14.12, and -14.45 kCal / mol. Conductance of protons through the electron transport chain (reciprocal of resistance (1 / R) is calculated as the slope over the linear range of JO2vs. -13.38, -13.71, -14.12, and -14.45 based on Ohms law (I=V / R). Procedural: Oroboros O2k (Innsbruck, Austria) was maintained at 37oC and 500 rpm in 0.5 ml small volume chambers for each experiment. Chambers were calibrated with buffer D (BxD) [KMES (105 mM), KCl (30 mM), EGTA (1 mM), KH2PO4(10 mM), MgCl2-6H2O (5 mM), 0.05% BSA, pH7.1, solubility factor 0.966] to assess R1 (air saturation, ~200 μM O2) and R0 (zero oxygen) with sodium hydrosulfide (Sigma S1256). Respiratory assessments of oxygen flux (JO2(pmol / sec / mg)) were made with BxD supplemented with 5 mM creatine monohydrate and 30 μg of mitochondrial protein. Following addition of mitochondria substrate-mediated respiration (non-phosphorylating) was performed for two separate substrate conditions: (1) malate (2.5 mM) and pyruvate (5 mM) and (2) malate (2.5 mM) and octanoyl carnitine (0.2 mM). Phosphorylating (maximal) respiration (ΔGATP-12.94) was assessed following the addition of ATP (5 mM), creatine kinase (20 mM), and PCr (1 mM). Cytochrome c (0.005 mM) was utilized to assess integrity with an a priori threshold of 15% increase in respiration, which did not require exclusion of any samples. Consecutive PCr titrations were then added at 1 mM (ΔGATP-13.38 kCal / mol), 2 mM (ΔGATP-13.71 kCal / mol), 4 mM (ΔGATP-14.12 kCal / mol), and 6 mM (ΔGATP- 14.45 kCal / mol). Mitochondrial JH2O2Emission: Conceptual: Evaluation of oxidative stress and reactive oxygen species production was assessed via the Amplex Ultra Red (AUR) / horseradish peroxidase (HRP) Assay under the identical creatine kinase conditions described above with some modifications. The AUR reaction is measures the production of H2O2as it reacts with HRP to produce resorufin that is detected fluorometrically. Addition of superoxide dismutase (SOD) aids in the innermitochondrial conversion of superoxide radicals to H2O2, which is then emitted outside of the mitochondria to be detected by AUR. Further, a portion of superoxide could be buffered by endogenous antioxidants and limit clear interpretation of ROS production within muscle mitochondria. To this end, auranofin, a thioredoxin reductase inhibitor, was included, as this is a primary buffering system within cardiac and skeletal muscle. Auranofin has been further demonstrated to not impact respiration or conductance. A standard curve was performed to convert resorufin fluorescence to H2O2picomoles and JH2O2(pmol / min / mg). Electron leak provides for an estimation of oxygen consumed by ROS that does not contribute to JO2expressed as a percentage (JH2O2 / JO2*100) after converting JO2to pmol / min / mg at corresponding experimental conditions. Procedural: Fluorescence was assessed via a fluorolog-QM (Horiba Scientific, Edison, NJ) outfitted with a 4-rotor turret system, temperature control, and stir bar capacity (Quantum Northwest, Liberty Lake, WA). Reactions occurred in a 600 μl total volume with adapter cuvette at 37oC, 500 rpm, 565:600 ex / em conditions over 4 minutes for each reaction to reach a steady state for each JH2O2calculation. Buffer D described from JO2experiments was supplemented further with SOD (20 U / mL), HRP (1 U / mL), auranofin (0.001 mM), and AUR (0.02 mM) and collected for a background rate. 600 μg of mitochondria was added followed by substrates separately assessed under the M / P and M / Oct conditions for non-phosphorylating respiration (State 4 (S4). Phosphorylating respiration was assessed following addition of ATP (5 mM), creatine kinase (20 mM), and PCr (1 mM). Conductance JH2O2was assessed at ΔGATP-13.71 and -14.45 kCal / mol with 3 mM and 10 mM PCr additions, respectively. Mitochondria Isolation Buffer (pH 7.1) Reagent Source Product # CAS# Sucrose Fischer BP220 57-50-1 Mannitol Sigma M4125 69-65-8 EGTA Sigma E4378 67-42-5 HEPES Gibco 15630-080 7365-45-9 BSA Sigma A6003 9048-46-8 Buffer D (pH 7.1) Reagent Source Product # CAS# KMES Sigma M0895 39946-25-3 KCI Sigma P4504 7447-40-7 EGTA Sigma E4378 67-42-5 KH2PO4Sigma P0662 7778-77-0 MgCl2-6H2O Sigma M2670 7791-18-6 BSA Sigma A6003 9048-46-8 JO2Mitochondrial Respiration Flux Reagent Source Product # CAS#Sodium Hydrosulfide SigmaS1256 7775-14-6Potassium PyruvateCombi-Blocks QA-1116 4151-33-1Malate SigmaM7397 97-67-6Octanoyl Carnitine Sigma50892 25243-95-2 Creatine Kinase fromSigma10736988001Rabbit musclePhosphocreatine SigmaP1937 108321-17-1ATP SigmaA2383 102047-34-7Cytochrome C SigmaC2506 9007-43-6Creatine Monohydrate SigmaC3630 6020-87-7JH2O2Amplex Ultra Red Assay Reagent Source Product # CAS# Amplex Ultra Red ThermoFischer 36006AuranofinSigmaA6733HorseradishSigmaP8375 9003-99-0Peroxidase Superoxide Dismutase Sigma S9697 9054-89-1 Mitochondrial DNA copy number measurements DNA was extracted from heart tissues using the DNeasy Blood and Tissue kit (QIAGEN #69506) according to the manufacturer’s instructions. Mitochondrial copy number was measured as described by Quiros et al. (Curr Protoc Mouse Biol. 7(1) (2017) 47-54). Briefly, 50 ng DNA was used to measure the relative copy number of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA; for normalization) by qPCR using Taqman primers for mitochondrial gene ND1 and nuclear gene rpl32, respectively. Taqman primers used were as follows: for ND1: mt- ND1_CDU63R2, Rpl32: Mm07306626_gH. Gene expression analysis Real-time PCR was performed using Taqman primers. Briefly, RNA was extracted using TRizol (Life Technologies), followed by ethanol extraction. Reverse transcription was performed from 1μg of RNA using QuantiTect Reverse Transcription Kit according to the manufacturer’s instruction (Qiagen). Taqman primers were purchased from ThermoFisher as follows: Nppb: Mm01255770_g1, Col3a2: Mm00802300_m1. The Cq values from the genes were normalized using Rpl32 (Mm07306626_gH). Metabolomic Analysis. Untargeted metabolomic screening was performed using the Shimadzu GCMS-TQ8050 NX EI / CI / NCI mass spectrometry system. Briefly, freeze-clamped ventricle tissue samples (~12 mg) were homogenized in an extraction solution consisting of 90% methanol / water and containing d4-succinate and d4-myristic acid as internal standards. For plasma metabolomics, blood was collected using heparin at the time of terminal study and centrifuged at 1,500 x g for 10 minutes at 4°C. Ten microliters of plasma were mixed with 400 μL of the same extraction solution. All samples were dried and derivatized sequentially with O-methoxylamine hydrochloride in pyridine, followed by N-Trimethylsilyl-N-methyl trifluoroacetamide prior to GC-MS analysis. Bioinformatic analysis was conducted using MetaboAnalyst 6.0, which included the generation of heat maps and pathway impact analysis. Pathway analysis integrated p-values from pathway enrichment and visualized results where node color indicated statistical significance and node size reflected pathway impact values. Differences in metabolite abundance were evaluated using two- way ANOVA, with a p-value < 0.05 considered statistically significant. Data are presented as mean ± SEM. Super-resolution Stochastic Optical Reconstruction Microscopy (STORM) Imaging. 20 μm-thick cardiac sections were fixed with 4% PFA, permeabilized, and blocked to prevent non-specific binding. Primary antibody labeling was performed using anti-PERM1, anti- CKB, anti-TnC. Following primary labeling, tissue sections was incubated with goat anti-rabbit secondary antibodies conjugated to STORM compatible fluorophores. The secondary antibodies used was CF568, Alexa Fluor 647, and CF750. STORM imaging was conducted with a Vutara 350 microscope (Bruker, Billerica, MA, USA). For each fluorophore, 5000 frames were acquired, and 3D localizations was reconstructed and comparative protein-protein complexing quantified through pair correlation analysis using Vutara SRX software. Fluorophores were switched between targets to confirm data and account for differing blinking efficiencies. Statistics Specific statistical tests are indicated in legends to figures and tables. All the data were analyzed using Prism Ver. 10.2.3 (GraphPad Software LLC, Boston, MA). A value of p<0.05 was considered statistically significant. EXAMPLE 1- AAV-Perm1 remodels cardiac contractility. Following a longitudinal study which determined that PERM1 expression reached ~3-fold increase at 4 weeks after AAV-Perm1 injection (Figures 1A-B), analysis of PERM1 protein expression and echocardiography was performed in total of 13 AAV-GFP and 17 AAV-Perm1 mice. These experiments confirmed on average a 3-fold increase of PERM1 expression due to AAV-Perm1 as compared to AAV-GFP, although there was a considerable inter-animal variability (Figures 1C-D). Of note, AAV9-Perm1 vector did not change PERM1 expression in skeletal muscle (Figures 1E-F) and adipose tissue (Figures 1G-H), the other two organs / tissues in which PERM1 is endogenously expressed. As expected, PERM1 expression in adipose tissue is rather low. Echocardiography revealed that AAV9-Perm1 significantly remodeled cardiac contractility (Figures 1I-P, Table 1). The representative M-mode images (Figures 1I-J) demonstrate that the LV end-diastolic and end-systolic diameters were both reduced in AAV-Perm1 mouse, concomitant with a strong increase in the ejection fraction (EF) and end-systolic LV wall thickness. These effects were absent in the AAV-GFP mouse. Gene delivery of Perm1 produced a median increase of 21% in EF, whereas virtually no change was observed following gene delivery of GFP (Figure 1K). Furthermore, AAV-Perm1 significantly decreased diastolic and systolic LV diameters (Figures 1L-M), and significantly increased LV systolic wall thickness (Table 1). Of note, stroke volume, cardiac output, and diastolic LV function (assessed by mitral E / A ratio) were not changed by either of the AAV vectors (Table 1). Interestingly, the increase in EF (delta EF) due to AAV-Perm1 was strongly inversely correlated to the pre-AAV level of EF, whereas no correlation was noted in AAV-GFP group (Figures 1N-O). Essentially, hearts with lower baseline systolic function exhibited a comparatively greater improvement in contractile strength following AAV-Perm1 administration compared to those with initially higher function. In order to address potential sex differences in EF, 2-way ANOVA analysis of fold-change of EF increase was performed. The effect of AAV vector type (GFP vs Perm1), the effect of gender (males vs. females), and interaction of AAV type with gender were tested. This analysis showed only a significant effect of AAV vector type (p=0.0008). The effect of gender, as well as the interaction of AAV type with gender were not significant (p=0.4023 and p=0.6007, respectively). An interesting and important consequence of the heart remodeling is a significant increase in VO2max, an established indicator of cardiovascular fitness and aerobic endurance (Table 2). AAV-Perm1 did not alter the ratios of heart weight to body weight, heart weight to tibial length, and lung weight to tibial length (Figures 2A-C), suggesting the absence of anatomical hypertrophy. However, analysis of cardiomyocyte length and volume using 3D confocal microscopy of LV samples stained with Alexa-conjugated WGA revealed subtle but significant cellular-level remodeling (Figures 2D-I). The overall distribution of cell length shifted towards shorter lengths, while the overall distribution of cell volume shifted towards larger volumes (Figures 2H and 2I, respectively). There was no indication that AAV-Perm1 increased cardiac fibrosis (Figures 2J-L). Consistently, the upregulation of key collagen synthesis enzymes (Col3a1 and Col5a2), as well as cardiac pathological stress markers such as Nppb and CaMKII (Figure 2M) have not been observed. EXAMPLE 2- PERM1 interacts with TnC and increases its expression in the heart. The role of PERM1 in the cytosol has never been investigated. Thus, whether PERM1 interacts with contractile proteins, as part of the mechanisms that enhance systolic function was investigated. By pulling down FLAG-tagged Perm1 and probing with anti-TnC using cardiac tissue from AAV-Perm1 mice, it was found that that PERM1 binds to TnC, the protein translating calcium signaling into the force of cardiac contraction (Figure 3A). Moreover, AAV-Perm1 significantly increased protein expression of TnC (Figures 3B-C). EXAMPLE 3- AAV-Perm1 increases mitochondrial biogenesis AAV-Perm1 significantly increased the protein expression levels of PGC-1^, a key regulator of mitochondrial biogenesis (Figures 3B and 3D), and the mitochondrial DNA copy number (Figure 3E), confirming the role of PERM1 as an enhancer of energy metabolism. The subject invention establishes a novel role of PERM1 as a positive cardiac inotrope. At least in part, this effect can be explained by a direct interaction of PERM1 with TnC, a key regulator of contractile force. The observed increase in the protein expression of TnC in AAV- Perm1 mice might be a consequence of PERM1 stabilizing the association of TnC with the thin filament, thus, slowing its degradation. A considerable variability was found in the degree of functional changes due to AAV-Perm1 as assessed by echocardiography. This may be a combination of natural fluctuations in cardiac function, variable efficacy of the gene delivery, and yet unknown compensatory mechanisms which prevent excessive increase of EF in the context of PERM1 overexpression. There in an apparent contradiction between evidence of cellular remodeling (including the increase in overall cell volume) and the lack of macroscopic signs of cardiac hypertrophy. It was speculated that PERM1 overexpression induces a complex remodeling that probably combines changes in some parameters while maintaining invariance of other parameters. Perhaps there are mechanisms that compensate for increase in cellular volume by decrease in extracellular volume in the heart, in order to prevent the macroscopic hypertrophy. Assuming that extracellular space occupies ~25% of the total myocardial volume (Schwab et al., IEEE Trans Med Imaging. 2013 May;32(5):862-72. doi: 10.1109 / TMI.2013.2240693), there is a potential “room” to accommodate slightly larger cardiomyocytes without changing the total heart muscle volume or mass. Further studies of detailed myocardial composition will be necessary to fully resolve this issue. The observed pattern of remodeling - combining increased EF and reduced LV volume – can be beneficial in HFrEF and in a spectrum of conditions leading to dilated cardiomyopathy (DCM). Adding to this, the ability of PERM1 to enhance mitochondrial bioenergetics and cardiovascular fitness makes gene delivery of Perm1 a strong candidate for therapeutical management of HFrEF and DCM. EXAMPLE 4- AAV-Perm1 prevents systolic dysfunction during pressure overload AAV9-Perm1 injection in healthy intact C57BL / 6 mice achieved a three-fold increase in cardiac PERM1 expression which was associated with enhanced cardiac contractility measured 4 weeks post-injection. To investigate whether gene delivery of PERM1 via AAV9-Perm1 can prevent the decline of systolic function caused by pressure overload, transverse aortic constriction (TAC) surgery was performed in C57BL / 6 mice four weeks after retro-orbital administration of either AAV9-GFP (control) or AAV9-PERM1 (Fig. 4A). Hearts were harvested 8 weeks after TAC / Sham (12 weeks after AAV treatment) (Fig. 4A). Western blotting analysis confirmed (1) that PERM1 expression was significantly downregulated by TAC (61% of sham AAV-GFP, p<0.05) and (2) that AAV9-Perm1 in healthy mice induces a strong increase in PERM1 expression (Figs.4B-C). These two effects canceled each other, resulting in the maintenance of PERM1 at the normal level up to 8 weeks after TAC in mice treated with AAV-Perm1 prior to TAC. In other words, AAV-Perm1 prevented downregulation of PERM1 after TAC (Figs.4B-C). Echocardiography was conducted at four timepoints: (1) prior to AAV injection, (2) prior to TAC or sham surgery, (3) four weeks post-TAC, and (4) eight weeks post-TAC, just before terminal study (indicated by blue triangles in Fig. 4A). Left ventricular ejection fraction (LVEF) was significantly reduced in AAV9-GFP mice after TAC (32% vs. 68% in GFP TAC vs. GFP Sham, p<0.001, Figs. 4D-E). Strikingly, AAV-Perm1 fully preserved LVEF at basal levels during pressure overload, with no significant difference observed between PERM1 Sham and PERM1 TAC groups up to 8 weeks post-TAC (64% vs.66%, p<0.05, Figs.4D-E). TAC for 8 weeks significantly increased the heart weight to body weight (HW / BW) ratio in mice treated with AAV9-GFP (8.3 vs. 4.7 in GFP TAC vs. GFP Sham, p<0.05, Fig. 4F), indicating the development of cardiac hypertrophy. AAV-Perm1 administration abrogated TAC- induced pathological hypertrophy (5.1 vs. 4.6 in PERM1 TAC vs. PERM1 Sham, p>0.05, Fig. 4F). Masson’s trichrome staining of cardiac tissue revealed a significant increase in fibrosis following TAC in in mice treated with AAV9-GFP (25% vs. 16.5% in GFP TAC vs. GFP Sham, p<0.05, Figs. 4G-H), whereas AAV-Perm1 treatment prior to TAC prevented this increase (Figs. 4G-H). Furthermore, qPCR analysis of cardiac tissue showed a significant increase in the mRNA levels of BNP (Nppb), a marker of cardiac stress, in GFP TAC hearts (10-fold increase in GFP TAC compared with GFP Sham, p<0.05), whereas BNP expression remained at basal levels in both PERM1 Sham and PERM1 TAC hearts (p>0.05 vs. GFP Sham, Fig. 4I). On average, the expression of Col3a1, a gene involved in collagen synthesis and fibrosis, was increased in GFP- TAC hearts (2.3-fold change vs. GFP Sham). The excessively high levels of Col3a1 observed in a subgroup of GFPTAC hearts was not present in the PERM1 TAC group (Fig.4J). In summary, these results suggest that gene delivery of PERM1 prevents the three major pathological symptoms of heart failure: decline in the systolic contractile function, pathological hypertrophy, and fibrosis. EXAMPLE 5- PERM1 overexpression protects mitochondrial respiration and oxidative stress against TAC in a substrate-dependent manner. Adenovirus-mediated PERM1 overexpression enhances both glucose and fatty acid oxidative capacity in cardiomyocytes. Mitochondrial respiratory capacity is known to be reduced in the failing heart, partly due to impaired fatty acid oxidation. To investigate whether AAV- mediated gene delivery of PERM1 can preserve mitochondrial energetics under pressure overload, a comprehensive analysis of mitochondrial respiration was performed in isolated heart mitochondria from mice treated with either GFP or AAV-Perm1 and subjected either to Sham or TAC surgery (8 weeks). Mitochondrial respiration was assessed using the Oroboros O2k system. Complex I-mediated respiration was evaluated through the TCA cycle using pyruvate and malate (Pyr / M), and fatty acid-dependent respiration using medium-chain fatty acid octanoyl-carnitine and malate (Oct / M). The creatine kinase clamp was employed to assess mitochondrial respiratory flux (JO2) under a range of physiological energetic demands by titrating phosphocreatine. Under Pyr / M-supported conditions, non-phosphorylating respiration (state 2) was significantly reduced in TAC hearts compared to Sham in the GFP group (991 vs. 457 pmol / s / mg, p<0.05). AAV-Perm1 administration significantly increased basal non-phosphorylating respiration compared to GFP Sham controls (1727 vs. 991 pmol / s / mg, p<0.05; Fig. 5A). Remarkably, AAV- Perm1 preserved mitochondrial respiration under pressure overload, with PERM1-TAC values remaining comparable to Sham levels (1727 vs. 1441 pmol / s / mg, Fig. 5A). A similar protective effect was observed in maximally stimulated respiration at ΔGATP−12.94. The protective role of PERM1 was further confirmed by an increased respiratory conductance (slope of JO2vs. ΔGATP) and improved respiration across all levels of energetic demand (Fig.5B). Consistent with these findings, the PERM1-Sham group exhibited significantly elevated non-phosphorylating respiration in the Oct / M condition compared to GFP-Sham (p<0.05), indicating enhanced fatty acid oxidation (FAO) capacity. Importantly, AAV-Perm1 treatment preserved basal JO2 under pressure overload, maintaining values comparable to GFP-Sham (Fig. 5C). However, unlike the Pyr / M condition, the protective effect of PERM1 on non- phosphorylating respiration under Oct / M was diminished from the elevated baseline observed in the Sham group (2022 vs. 1250 pmol / s / mg, PERM1-Sham vs. PERM1-TAC, p<0.05, Fig. 5C). Maximal respiration at ΔGATP−12.94 was enhanced by AAV-Perm1 and remained preserved under TAC stress (Fig. 5D). Interestingly, conductance in the Oct / M condition was more strongly enhanced by PERM1 overexpression than in Pyr / M, yet TAC still imposed a significant negative effect (Figs. 5E–H). Pathological stress in heart failure is accompanied by elevated oxidative stress and excessive mitochondrial reactive oxygen species (ROS) production. To determine whether preserved mitochondrial respiration by AAV-Perm1 also suppresses ROS, H2O2flux (JH2O2) was measured in the same heart mitochondria used for JO2analysis. Two key parameters were assessed: (1) the absolute H2O2flux, and (2) the electron leak—defined as JH2O2 / JO2x 100— representing the fraction of electron flow diverted to ROS production rather than ATP generation. The creatine kinase clamp allowed parallel assessment under identical respiratory states. In the Pyr / M condition, JH2O2flux was not significantly altered by either PERM1 or TAC under any respiratory state (Figs. 5I–J). In the Oct / M condition, JH2O2was largely unchanged, except at ΔGATP−14.45, where a main effect of PERM1 was observed (p<0.05, Figs. 5K-L). Electron leak, considered a more physiologically relevant indicator of mitochondrial redox imbalance, was significantly increased at resting (non-phosphorylating) conditions following TAC, but was reduced by PERM1 treatment in the Pyr / M condition (Figs. 5M-N). Specifically, TAC elevated leak at low energetic demand, while PERM1 restored leak to control levels, suggesting preserved redox homeostasis. In the Oct / M condition, JH2O2was not elevated, but electron leak was modestly increased at maximal respiration under TAC (p= 0.061 and 0.053 at ΔGATP−13.71; Figs.5O-P), indicating substrate-dependent vulnerability to redox stress. In summary, these results show that AAV-Perm1 enhances both pyruvate- and fatty acid- mediated mitochondrial respiration in the heart, and that it prevents TAC-induced respiratory impairment. The protection appears substrate-dependent: PERM1 fully preserved respiration in the pyruvate condition, whereas protection in the fatty acid condition was partial. While AAV-Perm1 did not significantly suppress H2O2production, it effectively reduced electron leak in a substrate and state-dependent manner, highlighting its protective role in maintaining mitochondrial efficiency during pressure overload. EXAMPLE 6- AAV-Perm1 preserves mitochondrial biogenesis and the expression of nuclear receptors during pressure overload. Genes and proteins involved in mitochondrial oxidative phosphorylation (OXPHOS) are primarily regulated by nuclear receptors and transcriptional coactivators such as estrogen-related receptors (ERRs), PGC-1 coactivators, peroxisome proliferator-activated receptors (PPARs), and nuclear respiratory factors (NRFs), which orchestrate the expression of OXPHOS genes in response to increased energy demands. In contrast, mitochondrial dysfunction in the failing heart is often associated with downregulation of these transcription factors and cofactors. PERM1 regulates the expression of ERRs and PPARα, along with their downstream targets involved in the mitochondrial electron transport chain (ETC) and fatty acid oxidation (FAO). To determine whether the preserved mitochondrial energetics observed in AAV-Perm1-treated hearts (Fig. 5) is associated with the expression of these transcriptional regulators, Western blot analyses were performed using cardiac tissue from Sham and TAC mice (8 weeks) treated with AAV-GFP or AAV-Perm1. TAC led to significant downregulation of ERRα, PPARα, NRF1, and TFAM in AAV-GFP hearts. However, all of these mitochondrial regulators were maintained at a normal (or above normal) levels in AAV-Perm1 mice (p<0.05, GFP-TAC vs. PERM1-TAC, Figs. 6A-H). Interestingly, while TAC did not affect PGC-1α or NRF2 protein expression in GFP-treated hearts (p>0.05), AAV-Perm1 significantly increased PGC-1α levels in both Sham and TAC conditions (133% and 132% of GFP Sham, respectively, p<0.05 for both). Consistent with the downregulation of ERRα and NRF1, their mitochondrial targets— cytochrome c (CytC) and ATP synthase b (Complex V)—were also reduced in GFP-TAC hearts (p<0.05 vs. GFP Sham), whereas in PERM1-TAC hearts the expression of these genes was maintained at least at the normal levels (p>0.05 vs. GFP Sham, Figs.6I-J). In contrast, neither TAC nor AAV-Perm1 affected the expression of CPT1b and CPT2 (the enzymes which mediate long-chain fatty acid uptake) and MCAD (enzyme responsible for metabolizing medium-chain fatty acids) (Figs. 6K-M). Lastly, myocardial the gene expression of glucose transporter GLUT1 was not affected with either TAC or overexpression of PERM1, whereas the gene expression of GLUT4 was significantly decreased with AAV-Perm1 in both Sham and TAC hearts (43% and 47% of GFP Sham, respectively, p<0.05, Figs.6O-P). Mitochondrial biogenesis is impaired in the failing human heart due to reduced mitochondrial DNA (mtDNA) replication and mtDNA deletion. AAV-Perm1 enhances mitochondrial biogenesis in healthy C57BL / 6 mouse hearts, as evidenced by increased mtDNA copy number and upregulation of PGC-1α. To investigate whether AAV-Perm1 preserves mitochondrial biogenesis under pressure overload, mtDNA copy number was quantified in Sham and TAC hearts from AAV-GFP and AAV-Perm1-treated mice. TAC led to a ~50% reduction in mtDNA (normalized to nuclear DNA) in GFP hearts (p<0.05, Fig. 6Q). AAV-Perm1 significantly increased mtDNA copy number compared to GFP Sham (1.0 vs. 1.5, p<0.05) and maintained it during TAC (1.5 in Sham vs. 1.3 in TAC, p>0.05). This was consistent with Western blot data showing that TFAM, a key transcription factor for mtDNA replication, was downregulated by TAC in GFP hearts but upregulated by AAV-Perm1 in both Sham and TAC conditions (136% and 174% of GFP Sham, respectively, p<0.05, Figs.6A-B). To assess whether AAV-Perm1 influences mitophagy as a mechanism for preserving mitochondrial content, protein levels of OPA1 and mitofusin 1—key regulators of mitochondrial fusion and fission were examined. TAC did not alter the expression of these proteins in GFP- treated hearts (p>0.05), but AAV-Perm1 significantly increased OPA1 expression in both Sham and TAC groups. In summary, these results, together with data presented in Fig. 5, demonstrate that AAV- Perm1 preserves both mitochondrial biogenesis and bioenergetics in the pressure-overloaded heart. This protective effect is associated with the maintenance or upregulation of key transcriptional regulators and structural components of mitochondrial oxidative phosphorylation. EXAMPLE 7- Metabolomics analysis reveals a distinct profile in AAV-Perm1 hearts during pressure overload. To determine whether preserved mitochondrial bioenergetics by AAV-Perm1 under pressure overload altered the cardiac metabolome, untargeted metabolomics were performed on cardiac tissue from AAV-GFP and AAV-Perm1 mice subjected to Sham or TAC surgery (8 weeks post-surgery). Principal component analysis (PCA) revealed a subtle but statistically significant difference between GFP Sham and GFP TAC hearts (p<0.05, Fig. 7A), indicating that TAC induces global changes in the cardiac metabolomic profile. Integrated pathway enrichment and topology analysis using MetaboAnalyst 6.0 identified several metabolic pathways significantly affected by TAC, including ketone body metabolism, the tricarboxylic acid (TCA) cycle, carnitine synthesis, and fatty acid and pyruvate metabolism (Figs. 7B-C). In contrast, the PCA plot comparing PERM1 Sham and PERM1 TAC hearts showed no significant separation (p<0.05, Fig. 7D), although modest changes were observed in linoleic acid metabolism and amino acid metabolism (Figs. 7D-E). Furthermore, the 3D PCA plot comparing GFP TAC and PERM1 TAC hearts revealed distinct metabolic profiles (Fig. 7F). Specifically, TAC-induced accumulation of spermidine and TCA cycle intermediates, including succinate, fumarate, and malate, was normalized by AAV-Perm1 (Figs. 7G-H). Collectively, these metabolomic analyses demonstrate that TAC disrupts multiple metabolic pathways converging on oxidative phosphorylation (OXPHOS), and that AAV-Perm1 partially restores metabolic homeostasis under pressure overload conditions. EXAMPLE 8- AAV-Perm1 prevents excessive O-GlcNAcylation in the heart during pressure overload. OGlcNAcylation is a post-translational modification of proteins that is regulated by two enzymes: OGlcNAc transferase (OGT) that adds O-GlcNAc to proteins; O-GlcNAcase (OGA) that removes OGlcNAc from proteins. Excessive or prolonged activation of O-GlcNAcylation is associated with heart failure and hypertrophy. PERM1 negatively regulates O-GlcNAcylation by repressing Ogt expression through transcriptional regulation. To determine whether the cardioprotective effect of AAV-Perm1 involves suppression of excessive O-GlcNAcylation, western blot analysis was performed to assess total O-GlcNAcylated proteins and the expression levels of OGT and OGA. In agreement with previous studies in human failing hearts and TAC mouse models, 8 weeks of TAC induced a significant increase in both high molecular weight (HMW) and low molecular weight (LMW) fractions of total O-GlcNAcylated proteins (Figs. 8A- C) and upregulation of OGT (Fig. 8D). AAV-Perm1 treatment prior to TAC prevented the increase in both O-GlcNAcylation and OGT expression, maintaining levels comparable to baseline (Fig. 8). There was a trend towards increased OGA expression in AAV-PERM1 Sham mice, which did not reach statistical significance due to a large dispersion in outcomes, but otherwise the OGA expression was minimally affected by either TAC or AAV-PERM1 (Fig.8E). EXAMPLE 9- PERM1 co-localizes with creatine kinase and facilitates its interaction with Troponin C. AAV-mediated overexpression of PERM1 enhances cardiac contractility in healthy hearts that are not limited by ATP availability, suggesting that PERM1 may function beyond simply promoting ATP production. Creatine kinase (CK) plays a key role in shuttling ATP produced in mitochondria to sites of ATP utilization. In the heart, approximately 90% of mitochondrial ATP is consumed to support contractility. To test whether PERM1 interacts with CK in the heart, co-immunoprecipitation (Co-IP) assays were performed using WT heart tissue. Pulldown with anti-CK antibodies revealed that CK interacts with PERM1 (Fig. 9A). Furthermore, pulldown assays using both anti-CK and anti- PERM1 antibodies demonstrated that troponin C (TnC), a key component of the contractile apparatus in the sarcomere, forms complexes with both CK and PERM1 in WT and AAV- PERM1-treated hearts (Fig.9B). To further assess these interactions in situ, super-resolution Stochastic Optical Reconstruction Microscopy (STORM) was employed to visualize cardiac tissue from AAV- Perm1-treated (gain-of-function) and PERM1-knockout (loss-of-function) mice. AAV-Perm1 treatment enhances cardiac contractility, while PERM1 deletion results in significantly reduced left ventricular ejection fraction (LVEF). STORM imaging, which enables nanoscale resolution of molecular localization, showed that PERM1 co-localizes with TnC in AAV-Perm1 hearts (Figs. 9C-D), consistent with the Co-IP results (Figs. 9B) and prior findings. Additionally, TnC co- localizes with CK in AAV-Perm1 hearts, whereas this co-localization was markedly reduced in PERM1-null hearts (Figs.9E-G). These results suggest that PERM1 promotes the spatial coupling of CK with TnC, potentially enhancing the efficiency of ATP delivery to the sarcomere and thereby supporting contractile function. In the present invention, AAV-Perm1 prevents the onset of heart failure in response to pressure overload by cardiac contractility, mitochondrial biogenesis, and mitochondrial respiratory capacity. The cardioprotective effects of AAV-Perm1 were also associated with suppression of cardiac hypertrophy and fibrosis. PERM1 interacts with creatine kinase (CK), potentially facilitating the coupling between ATP production and contractile function. In the present invention, AAV-Perm1 expression remained stable during pressure overload which fully prevented the development of HFrEF. These effects were consistent with—but exceeded—those observed in transgenic mice with constitutive PERM1 overexpression, confirming the therapeutic effect of PERM1 and establishing AAV-Perm1 as a practical and translationally relevant gene therapy strategy. The results demonstrate that AAV-Perm1 enhances mitochondrial respiration supported both pyruvate / malate and octanoylcarnitine / malate substrates. Notably, enhanced pyruvate-driven respiration was preserved even under TAC, whereas fatty acid–driven respiration returned to baseline. These findings suggest that PERM1 exerts substrate-specific effects, preferentially supporting TCA cycle metabolism under stress. Enhanced mitochondrial conductance under both conditions further supports a role for PERM1 in maintaining mitochondrial quality. AAV-Perm1 attenuates TAC-induced cardiac fibrosis and hypertrophy. The RNA-seq data show that PERM1 knockdown upregulates pro-fibrotic genes such as Col3a1 and Col5a2—both induced by TAC and suppressed by AAV-Perm1. Regarding hypertrophy, PERM1 overexpression downregulates GLUT4, with limited enhancement of glucose-driven respiration compared to pyruvate. Given that the pentose phosphate pathway (PPP)—an accessory glucose pathway—is often upregulated in hypertrophy and supports nucleotide synthesis, it is plausible that AAV- Perm1 limits hypertrophy by restricting glucose uptake and PPP activation. In conclusion, the present invention provides PERM1 as a therapeutic target for HFrEF. AAV-Perm1 gene therapy preserves mitochondrial biogenesis, enhances mitochondrial function, improves contractility, and reduces fibrosis—without inducing adverse remodeling. Accordingly, PERM1-based gene therapies can be used to restore energetic and mechanical homeostasis in the failing heart. EXAMPLE 10- Injection of AAV-Perm1-FLAG vector has a larger inotropic effect than injection of AAV-Perm1 (no FLAG). FLAG tag, having the sequence DYKDDDDK (where D=aspartic acid, Y=tyrosine, and K=lysine), is a peptide / protein tag, which is an artificial antigen to which specific, high affinity monoclonal antibodies can bind. PERM1 was modified to have a FLAG tag using recombinant DNA technology, arriving at PERM1-FLAG that provides an opportunity to track PERM1 expression more precisely. The AAV-Perm1 vector was modified to have FLAG tag attached to its C-terminus. FLAG tag can be recognized by specific anti-FLAG antibodies, providing precise information regarding the transgene as the FLAG sequence is not present in cells natively. To investigate whether the presence of FLAG affect the transgene function, two AAV- PERM1 vectors (SignaGen Laboratories), one of which carries a native mouse PERM1 sequence (no FLAG) and the other carries mouse PERM1 sequence with FLAG attached to its C-terminus, were used. The result shows that addition of FLAG enhances the effect of AAV-Perm1 with respect to the strength of heart muscle contraction. Fig. 10 shows that AAV-Perm1 vector that carries PERM1 with FLAG sequence attached to the C-terminus has a stronger physiological effect (stronger increase in the left ventricular ejection fraction (LVEF) after AAV injection) than the PERM1 protein without FLAG. Moreover, in the presence of FLAG, there is a significant increase in LVEF post-injection, whereas in the absence of FLAG, there is no significant increase in LVEF post-injection (Fig.10). All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification. It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.

Claims

CLAIMS We Claim:

1. A method for treating a disease associated with impaired muscle contraction and mitochondrial function, the method comprising administering, to a subject in need thereof, (1) a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 90% identity with a PERM1 protein; (2) a PERM1 protein or a variant or fragment thereof; or (3) an AAV gene therapy vector comprising a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 90% identity with a PERM1 protein.

2. The method of claim 1, wherein the disease is a cardiovascular disease or aging-related disease.

3. The method of claim 2, wherein the cardiovascular disease is heart failure or diabetic cardiomyopathy.

4. The method of claim 2, wherein the cardiovascular disease is heart failure with reduced ejection fraction (HFrEF).

5. The method of claim 1, wherein the administration is oral, subcutaneous, intradermal, intravenous, intravascular, intramuscular, intraperitoneal, or intrasternal administration.

6. The method of claim 1, wherein the AAV gene therapy vector further comprises a promoter, a terminator, and optionally, ITR sequences at 3’ and 5’ ends.

7. The method of claim 1, wherein the AAV gene therapy vector is serotype 1, 2, 4, 5, 6, 8 or 9.

8. The method of claim 6, wherein the promotor is selected from CBh and CMV.

9. The method of claim 6, wherein the terminator is BGH polyA or hGH polyA.

10. The method of claim 1, further comprising assessing / measuring / determining systolic and diastolic left ventricular (LV) function, assessing / measuring / determining diastolic and systolic LV diameters, assessing / measuring / determining LV systolic wall thickness and / or assessing / measuring / determining VO2max.

11. A method for enhancing cardiac contractility of a subject with heart failure, the method comprising administering to the subject one of the following: (1) a polynucleotide that encodes a PERM1 protein or a peptide having an amino acid sequence sharing at least 90% identity with a PERM1 protein; (2) a PERM1 protein or a variant or fragment thereof; and (3) an AAV gene therapy vector comprising the polynucleotide of (1).

12. The method of claim 11, wherein the subject with heart failure has impaired muscle contraction and mitochondrial function.

13. The method of claim 11, wherein the subject with heart failure has HFrEF.

14. The method of claim 11, wherein the administration is oral, subcutaneous, intradermal, intravenous, intravascular, intramuscular, intraperitoneal, or intrasternal administration.

15. The method of claim 11, further comprising assessing / measuring / determining systolic and diastolic left ventricular (LV) function, assessing / measuring / determining diastolic and systolic LV diameters, assessing / measuring / determining LV systolic wall thickness and / or assessing / measuring / determining VO2max.

16. The method of claim 11, wherein the AAV gene therapy further comprises a promoter, a terminator, and optionally, ITR sequences at 3’ and 5’ ends.

17. The method of claim 11, wherein the AAV gene therapy vector is serotype 1, 2, 4, 5, 6, 8 or 9.

18. The method of claim 16, wherein the promotor is selected from CBh, and CMV.

19. The method of claim 16, the terminator being BGH polyA or hGH polyA.