Application of methionine adenosine transferase 2A and related substances thereof in preparation of wound repair products

Abstract

The invention relates to the technical field of biological medicines, and discloses application of methionine adenosine transferase 2A and related substances thereof in preparation of wound repair products. According to the application disclosed by the invention, a metabolic regulation network in a diabetic wound surface is researched, so that MAT2A expression down-regulated in pericytes is found to be remarkably and negatively correlated with M1 type macrophage infiltration, and the situation that the wound healing is delayed, the wound surface blood perfusion is reduced and the inflammation macrophage infiltration is increased due to MAT2A specific deletion of the pericytes in the wound is observed; and after saMAT2A-loaded pericellular membrane coated lipid nanoparticles (PMCNPs) are further adopted for treatment, the regeneration process of the wound surface can be remarkably enhanced, continuous inflammatory macrophage infiltration in the diabetic wound surface is relieved, microcirculation recovery is promoted, the safety is high, and good application prospects are achieved in the aspect of promoting wound surface repair.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine technology, and in particular to the application of methionine adenosyltransferase 2A and related substances in the preparation of wound repair products. Background Art

[0002] Wound repair and tissue regeneration after trauma are major challenges in contemporary medicine. In metazoans, tissue regeneration relies on the coordinated and sequential advancement of various components within the wound microenvironment. Complex intercellular communication involves not only classic protein ligand-receptor binding but also the diffusion of messengers within the microenvironment. Furthermore, the gene expression patterns and even metabolic states of neighboring cells can produce a domino effect to regulate tissue regeneration and repair.

[0003] Related studies have shown that inflammation and the conversion of alternatively activated macrophages are crucial in the wound healing process. With the development of high-depth omics technologies, researchers have improved their understanding of the tissue repair process. However, in some complex cases, such as wound healing in diabetic patients, it remains a huge challenge. Diabetic wounds are a serious global medical problem with a 5-year survival rate lower than that of common cancers and are the main cause of non-traumatic lower limb amputations. In the study of diabetic wounds, abnormal phenotypic conversion of macrophages has attracted the attention of researchers. Macrophages are crucial in mediating chronic inflammation associated with difficult-to-heal wounds. Previous studies have described the role of abnormal metabolites in promoting the persistent infiltration of inflammatory macrophages in diabetic wounds. However, the impact of cell-cell interactions on infiltrating macrophages in diabetic wounds remains unclear.

[0004] Based on this, there is an urgent need to further explore the wound repair mechanism and seek a wound repair drug that can treat wounds including diabetic wounds. Summary of the Invention

[0005] The purpose of the first aspect of the present invention is to provide the use of a substance related to methionine adenosyltransferase 2A (MAT2A) in the preparation of a wound repair product.

[0006] The second aspect of the present invention aims to provide a use of the MAT2A gene as a marker in preparing candidate compounds for wound repair screening.

[0007] The third aspect of the present invention aims to provide a lipid nanoparticle.

[0008] The fourth aspect of the present invention aims to provide a wound repair medicine.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is: The first aspect of the present invention provides the use of at least one of A1) to A4) in preparing a wound repair product; A1) MAT2A protein; A2) Substances that increase the activity of MAT2A protein; A3) substances that specifically express MAT2A protein; A4) Substances that promote MAT2A gene expression.

[0010] In some embodiments of the present invention, the ID number of the MAT2A protein is Gene ID: 4144.

[0011] Specifically, the amino acid sequence of the MAT2A protein is as follows: MNGQLNGFHEAFIEEGTFLFTSESVGEGHPDKICDQISDAVLDAHLQQDPDAKVACETVAKTGMILLAGEITSRAAIDYQKVVREAIKHIGYDDSSKGF DYKTCNVLVALEQQSPDIAQGVHLDRNEEDIGAGDQGLMFGYATDETEECMPLTIVLAHKLNAKLAELRRNGTLPWLRPDSKTQVTVQYMQDRGAVLPIR VHTIVISVQHDEEVCLDEMRDALKEKVIKAVVPAKYLDEDTIYHLQPSGRFVIGGPQGDAGLTGRKIIVDTYGGWGAHGGGAFSGKDYTKVDRSAAYAAR WVAKSLVKGGLCRRVLVQVSYAIGVSHPLSISIFHYGTSQKSERELLEIVKKNFDLRPGVIVRDLDLKKPIYQRTAAYGHFGRDSFPWEVPKKLKY (SEQ ID NO.1).

[0012] In some embodiments of the present invention, the substance that increases the activity of the MAT2A protein includes at least one of a small molecule compound, an antibody, a polypeptide, a carbohydrate, or a virus.

[0013] In some embodiments of the present invention, the substance that specifically expresses MAT2A includes at least one of the following: B1) a nucleic acid molecule encoding the MAT2A protein; B2) An expression cassette, vector or transgenic cell line comprising the nucleic acid molecule described in B1).

[0014] In some embodiments of the present invention, the substance that specifically promotes MAT2A gene expression includes at least one of a nucleic acid drug containing a promoter or enhancer of MAT2A expression, a small molecule agonist or a polypeptide agonist that promotes the expression of a gene encoding MAT2A protein.

[0015] In some embodiments of the invention, the nucleic acid molecule comprises at least one of DNA, mRNA, circRNA, or saRNA.

[0016] In some embodiments of the present invention, the nucleic acid molecule encoding the MAT2A protein comprises the sequence shown in SED ID NO.2.

[0017] In some embodiments of the present invention, the wound repair includes diabetic wound repair and non-diabetic wound repair.

[0018] In some embodiments of the present invention, the functions of the wound repair product include any one of C1) to C4): C1) Promote wound healing; C2) Increase blood perfusion at the skin surface; C3) increasing the proportion of Ki-67 positive cells and / or increasing the expression level of α-SMA; C4) Reduce the content of pro-inflammatory factors and / or increase the number of anti-inflammatory macrophages.

[0019] The second aspect of the present invention provides the use of the MAT2A gene as a marker in preparing and screening candidate compounds for wound repair.

[0020] In some embodiments of the present invention, the step of screening candidate compounds for wound repair comprises: In the test group, a test compound is added to the cell culture system, and the expression level and / or activity of MAT2A in the cells of the test group is observed; in the control group, no test compound is added to the same cell culture system, and the expression level and / or activity of MAT2A in the cells of the control group is observed; Among them, if the expression level and / or activity of MAT2A in the cells of the test group is higher than that of the control group, it indicates that the test compound has a promoting effect on the expression and / or activity of MAT2A and is a candidate compound that can be used for wound repair.

[0021] In some embodiments of the present invention, the steps further include: conducting further cell experiments and / or animal experiments on the obtained candidate compounds to further select and determine substances useful for wound repair from the candidate compounds.

[0022] In some embodiments of the present invention, the system for screening candidate compounds for wound repair is not limited to a cell system, a subcellular system, a solution system, a tissue system, an organ system or an animal system, etc. The system is not limited to the above forms, as long as the system can detect whether the test compound can increase the expression and / or activity of MAT2A.

[0023] In some embodiments of the present invention, the candidate compounds include but are not limited to nucleic acid promoters, binding molecules (such as antibodies or ligands), small molecule compounds, etc. designed for the MAT2A gene or the protein it encodes or its upstream or downstream genes or proteins.

[0024] The third aspect of the present invention provides a lipid nanoparticle, wherein the raw materials for preparing the lipid nanoparticle include lipids and at least one of A1) to A4); A1) MAT2A protein; A2) Substances that increase the activity of MAT2A protein; A3) substances that specifically express MAT2A protein; A4) Substances that promote MAT2A gene expression.

[0025] In some embodiments of the invention, the lipid comprises at least one of an ionizable cationic lipid, a helper lipid, cholesterol, and a PEGylated lipid.

[0026] Ionizable cationic lipids, a key component of lipid nanoparticles (LNPs), can bind to negatively charged nucleic acids (such as mRNA or siRNA) through electrostatic interactions to form stable complexes. Furthermore, ionizable cationic lipids can be protonated in the acidic environment of endosomes, carrying a positive charge, thereby facilitating the escape of LNPs from endosomes and releasing nucleic acids into the cytoplasm.

[0027] Helper lipids are neutral plasmids that are often used as structural lipids in lipid nanoparticle formulations because they can spontaneously organize into lipid bilayers and their higher phase transition temperature can enhance the membrane stability of lipid nanoparticles.

[0028] In some embodiments of the present invention, the auxiliary lipid includes at least one of DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), DSPC (1,2-distearoyl-sn-glycero-3-phosphatidylcholine), and DOPC (1,2-dioleoyl-sn-glycero-3-phosphatidylcholine).

[0029] In some embodiments of the present invention, the raw materials for preparing the lipid nanoparticles include a substance that specifically expresses the MAT2A protein, an ionizable cationic lipid, an auxiliary lipid, cholesterol, and a pegylated lipid.

[0030] In some embodiments of the present invention, the substance that specifically expresses MAT2A protein is MAT2A saRNA.

[0031] Compared to traditional mRNA technology, saRNA-based technology is considered a more advanced form of RNA therapy due to its lower dosage requirements, relatively fewer side effects, and longer-lasting therapeutic effects. It is widely used in the development of vaccines for cancer and infectious diseases. The efficacy of RNA therapy in targeting specific sites and maintaining stable function is heavily dependent on the delivery vehicle used. Among them, lipid nanoparticles represent the fastest-growing class of drug delivery systems, characterized by excellent biocompatibility, considerable loading capacity, and high bioavailability. Loading MAT2A saRNA into lipid nanoparticles for treatment can help improve the durability of therapeutic effects while reducing side effects.

[0032] In some embodiments of the present invention, the molar ratio of the ionizable cationic lipid, the helper lipid, the cholesterol and the PEGylated lipid is 40-60:5-15:35-40:1-2.

[0033] In some embodiments of the present invention, the lipid nanoparticles are coated with a cell membrane.

[0034] In some embodiments of the invention, the cell membrane comprises a pericyte membrane.

[0035] Pericytes are multipotent cells wrapped around the walls of capillaries. They play a key role in the repair of various tissues by mediating processes such as cell migration, regeneration and signal transduction. They can initiate the chemotactic migration of interstitial neutrophils and macrophages to the site of tissue damage, which is a "highway" for the rapid migration of extravasated cells of the innate immune system along blood vessels, thereby regulating local inflammation after tissue damage. In addition, pericytes are an important component of angiogenesis. The present invention found through in vivo experiments that the blood perfusion of the wound surface of the MAT2A-deficient group was reduced, indicating that the downregulation of pericyte MAT2A expression is potentially pathogenic to the microcirculatory disorder of diabetic wounds. The use of pericyte membranes for coating can help improve biocompatibility and targeting effects.

[0036] Modification of synthetic nanoparticles with natural cell membrane materials has demonstrated enhanced cell-targeting capabilities and reduced susceptibility to clearance by the immune surveillance system. In this study, pericyte membrane-coated lipid nanoparticles (PMCNPs) loaded with saMAT2A (i.e., MAT2A saRNA) exhibited strong targeting to diabetic pericytes, facilitating stable expression of MAT2A. Furthermore, in a diabetic mouse wound model, PMCNPs significantly enhanced wound regeneration, reduced persistent inflammatory macrophage infiltration in diabetic wounds, and promoted microcirculatory recovery.

[0037] A fourth aspect of the present invention provides a wound repair drug comprising at least one of A1) to A4) or any one of the lipid nanoparticles described in the third aspect; A1) MAT2A protein; A2) Substances that increase the activity of MAT2A protein; A3) substances that specifically express MAT2A protein; A4) Substances that promote MAT2A gene expression.

[0038] In some embodiments of the present invention, the drug further comprises a pharmaceutically acceptable excipient.

[0039] In some embodiments of the present invention, the pharmaceutically acceptable excipients include at least one of a diluent, a binder, a wetting agent, a lubricant, a disintegrant, a solvent, an emulsifier, a solubility aid, a preservative, a pH regulator, an osmotic pressure regulator, a surfactant, a coating material, an antioxidant or a buffer.

[0040] In some embodiments of the present invention, the dosage form of the pharmaceutical composition includes at least one of a suspension, granules, capsules, powders, tablets, emulsions, solutions, pills, injections, oral preparations, suppositories, enemas, aerosols, patches or drops.

[0041] In some embodiments of the present invention, the administration route of the pharmaceutical composition includes at least one of intravenous injection, intraperitoneal injection, intramuscular injection, subcutaneous injection, oral administration, sublingual administration, nasal administration, aerosol administration or transdermal administration.

[0042] The present invention has at least the following beneficial effects: (1) By studying the metabolic regulatory network in diabetic wounds, the present invention found that downregulated MAT2A expression in pericytes was significantly negatively correlated with M1 macrophage infiltration, and observed that pericyte-specific loss of MAT2A in wounds led to delayed wound healing, accompanied by increased infiltration of inflammatory macrophages. In addition, the present invention found through in vivo experiments that blood perfusion in the wounds of the MAT2A-deficient group was reduced, further indicating a potential pathogenic relationship between downregulated pericyte MAT2A expression and microcirculatory disturbances in diabetic wounds.

[0043] (2) The present invention constructs pericyte membrane-coated lipid nanoparticles (PMCNPs) loaded with saMAT2A, which have strong targeting properties for diabetic pericytes and stably express MAT2A. In a diabetic mouse wound model, it was found that treatment with PMCNPs can significantly enhance wound regeneration, reduce persistent inflammatory macrophage infiltration in diabetic wounds, and promote the recovery of microcirculation. This shows that substances expressing the MAT2A gene have great application prospects in promoting wound repair.

[0044] Other features and advantages of the present invention will be set forth in the description that follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 The experimental results are related to the identification of candidate metabolic enzymes closely related to inflammatory macrophage infiltration in DWs, including: (A) Flowchart of multi-omics analysis used to study inflammatory macrophage infiltration in DWs; (B) is the score diagram of the separation of metabolic gene patterns between the DW group and the NDW group analyzed by PCA; (C) Volcano plot showing the differential expression of metabolic genes between DWs and NDWs; (D) KEGG analysis of typical differential metabolic pathways between DWs and NDWs; (E) t-SNE plot of characteristic cell clusters identified by scRNA-seq of human wound samples (GSE165816); (F) Venn diagram showing the co-changed metabolic differential genes and their origins; (G) Correlation analysis between the expression levels of candidate differential metabolic genes and inflammatory macrophage infiltration scores; (H) Cell communication analysis to reveal potential interactions between pericytes with low MAT2A expression and other cell types; (I) Schematic diagram of methionine cycle and statistical results of methionine levels in the DW and NDW groups; (J) is the expression level of methionine cycle-related metabolic enzymes in the two groups, data are expressed as mean±SD, ** p <0.01; (K) Immunofluorescence staining showing the expression level of MAT2A in CD31-NG2+PDGFRβ+ pericytes in human wounds; (L) GSEA analysis results of MAT2A high expression samples and MAT2A low expression samples (GSE165816).

[0046] Figure 2The experimental results related to the construction of DWs metabolic network and the identification of scRNA-seq data are as follows: (A) Metabolic network describing the association of different essential metabolic pathways in diabetic wounds (GEO: GSE154556); (B) DisGeNET analysis results showing the association between metabolic disorders and disease characteristics; (C) Immune infiltration analysis results of GSE154556 DWs and NDWs; (D) tSNE plot of all characteristic cell clusters identified by scRNA-seq of human wound samples (GSE165816); (E) is a dot matrix showing the expression levels of typical marker genes in all major cell types; (F) Statistical results of the proportion of characteristic cell clusters in DWs and NDWs; (G) Statistical results of differentially expressed genes in characteristic cell clusters in the comparison between DWs and NDWs.

[0047] Figure 3 These are experimental results showing that pericyte MAT2A deficiency alters macrophage phenotype and impairs wound regeneration: (A) ScRNA-seq analysis process; (B) Western blot analysis of MAT2A expression in mouse skin pericytes; (C) Representative images of mouse skin wounds on days 0, 4, 8, 12, and 16 after surgical excision wound model preparation; (D) Representative blood perfusion images and statistical analysis of the wound surface on days 4 and 8 after surgery; (E) HE staining, Masson trichrome staining, and Ki-67, α-SMA, and IL6 immunohistochemical staining results of skin wound sections. Scale bar, 100 μm. (F) UMAP image showing identified mouse skin cell clusters; (G) Box plots representing the differences in abundance of the indicated cell types between the two groups; (H) Volcano plot showing differentially expressed genes in two groups of pericytes; (I) Histogram showing functional enrichment pathways associated with significantly up-regulated or down-regulated genes (MAT2A LOF vs. control) in pericyte clusters; (J) Cell communication analysis to reveal potential interactions between pericytes and other cell types; (K) Violin box plots representing the expression of pro-inflammatory or anti-inflammatory signature genes in macrophage clusters; (L) UMAP images and quantitative analysis results showing characteristic cell clusters of infiltrating macrophages and their proportions in the indicated groups; (M) Cell trajectory analysis of characteristic cell clusters of infiltrating macrophages; (N) Representative immunofluorescence images and statistical analysis of macrophage infiltration in skin wounds on day 8. Scale bar, 20 μm. Data are expressed as mean ± SD. **p < 0.01.

[0048] Figure 4 Results of pericyte isolation and immunohistochemical staining of mouse skin wounds, including: (A) is a diagram showing the process of isolating pericytes; (B) Flow cytometric analysis results of isolated pericytes; (C) Statistical analysis of epidermal thickness, Ki-67, α-SMA, and IL-6 staining in skin wounds (n=3).

[0049] Figure 5 Statistical results of mouse skin wound scRNA-seq data, including: (A) Violin plots showing the number of RNA features, number of counts, and percentage of mitochondria before (upper panel) and after (lower panel) quality control. (B) UMAP graph showing the combined results of the MAT2A LOF group and the control group; (C) Distribution diagram of 12 annotated cell clusters in the MAT2A LOF group and the control group; (D) is a dot matrix showing the expression levels of typical marker genes in all major cell types, where the color level indicates the expression level of the marker gene, and the size of the dot indicates the percentage of cells expressing the marker gene; (E) Identification and characterization results of macrophage subsets; (F) Statistical results of the ratio of pro-inflammatory and anti-inflammatory macrophages in each group; Figure 6 The results of the study are to target pericytes with MAT2A self-amplifying RNA and its effect on wound repair, including: (A) is the flow chart of the preparation of PMCNPs; (B) is the average diameter of PMCNPs; (C) is the measurement result of zeta potential of PMCNPs; (D) Transmission electron microscopy image of purified PMCNPs; (E) is the stability test result of PMCNPs; (F) Dose screening and statistical results of the maximum stable expression of PMCNPs within 24 hours; (G) Schematic diagram of the administration of PMCNPs in a mouse wound model; (H) Representative images of mouse skin wounds on days 0, 4, 8, 12, and 16 after surgical excision wound model; (I) Representative wound blood perfusion images and statistical analysis on postoperative day 4 and day 8 (n=3); (J) H&E staining, Masson's trichrome staining, and immunohistochemical staining of skin wound sections for Ki-67, α-SMA, and IL-6. Scale bar: 100 μm. (K) Flow cytometric analysis of macrophage infiltration in skin wounds on days 4 and 8. Representative histograms depict the levels of F4 / 80+CD86+ cells in skin wounds of each group. (L) Immunofluorescence images and analysis results showing macrophage infiltration in skin wounds on day 8, N = 3 per group, scale bar 20 μm; data are expressed as mean ± SD. * p <0.05,** p <0.01; ns, not significant.

[0050] Figure 7 Fluorescence images and statistical results of stable expression of PMCNPs at different time points.

[0051] Figure 8 Fluorescence images and statistical results for detecting the cellular uptake specificity of PMCNPs (500 ng / ml).

[0052] Figure 9 Figure 2 shows the statistical analysis results of α-SMA and IL-6 staining on skin wounds in each group (n=3), where: (A) is the α-SMA detection result; (B) is the IL-6 detection result.

[0053] Figure 10 The statistical results of peripheral blood glucose levels, food intake, and body weight of diabetic mice treated with or without PMCNPs are shown below: (A) is the peripheral blood glucose level test result; (B) is the food intake test result; (C) is the weight test result; Figure 11 Representative images of H&E staining of various organs from diabetic mice treated with the indicated treatments. The scale bar is 100 μm. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0055] The terms "preferably," "more preferably," and the like, used herein refer to embodiments of the present invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the present invention.

[0056] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are understood to include any and all subranges subsumed therein.

[0057] In the description of the present invention, the reference term "and / or" includes all and any combinations of one or more of the associated listed items.

[0058] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0059] Experimental Animals Experiments involving animals were approved by the Animal Research Committee and performed in accordance with established guidelines for the use and care of laboratory animals. C57BL / 6J, BKS / db, Mat2aem1Cflox / Gpt, and Cspg4em1Cin(CreERT2-P2A) / Gpt mice were purchased from GemPharmatech (Nanjing, China). All animals were housed in a specific pathogen-free environment with a 12-h light / dark cycle and provided with food and water ad libitum. All mice were randomized into groups before wound initiation. Skin samples were stored at −80°C if not used immediately.

[0060] Statistical Analysis The present invention uses SPSS 25.0 or GraphPad Prism 8.0 software for statistical analysis and drawing. Each experiment was repeated at least 3 times. All data are expressed as mean ± standard deviation. The sample size of different groups was determined based on previous literature in the same study area to ensure sufficient power to detect the preset effect. The t-test was used for single-factor comparison between two groups, and the single-factor analysis of variance and Tukey's multiple comparison test were used for comparison between multiple groups. For experimental designs involving a second variable, two-way analysis of variance with Tukey's multiple comparison was used. Correlation was analyzed by linear regression. p The difference was statistically significant when the value was <0.05.

[0061] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0062] Example 1: Identification of candidate metabolic enzymes associated with macrophage infiltration in diabetic wound inflammation In order to explore the correlation between metabolic disorders and infiltrating macrophages in the wound microenvironment, this example combines multi-omics analysis methods (such as Figure 1 (As shown in Figure A), candidate metabolic enzymes associated with macrophage infiltration in diabetic wound inflammation were identified. Specifically, the following are included.

[0063] 1. Metabolic network analysis To explore the changes in metabolic processes between diabetic wounds (DW) and non-diabetic wounds (NDW), this study identified metabolic enzymes, small molecule transporters, and metabolism-related transcription factors from the expression matrix (GEO: GSE154556) and performed principal component analysis (PCA).

[0064] The results are as follows Figure 1 As shown in Figure B, it can effectively distinguish the metabolic heterogeneity between the two groups. The KEGG analysis results of the typical differential metabolic pathways between DWs and NDWs showed that ( Figure 1 Compared with the NDW group, more than 500 differential metabolic genes were identified after manual screening, most of which were downregulated in the DW group. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and metabolic gene network analysis results are shown in Figure 3. Figure 1 D and Figure 2 As shown in Figure A, it reveals complex metabolic changes during the healing process. Figure 2 As shown in Figure B, these metabolic changes are characteristic of diabetes. In addition, the results of immune infiltration analysis of the expressed matrix are shown in Figure 4. Figure 2 As shown in Figure 3C, the proportion of inflammatory macrophages in diabetic wounds increases, which is consistent with mainstream research.

[0065] 2. Single-cell transcriptome analysis To reveal the primary cellular sources of these metabolic alterations, this study analyzed a single-cell transcriptome dataset of diabetic wounds using the following methods: First, scRNA-seq data of non-healing diabetic foot ulcers (DFUs) and healthy controls without diabetes were retrieved from the Gene Expression Omnibus (GEO) database (GSE165816). Low-quality cells were screened out according to the following criteria: (1) <200 expressed genes, (2) >30% of UMIs were derived from the mitochondrial genome. After integration, data preprocessing was performed in the same manner as above. Then, bulk RNA-seq data of skin lesions of diabetic patients and healthy subjects were obtained from the GEO database (GSE154556). Differentially expressed genes between skin lesions of diabetic patients and healthy controls were screened using the limma R package with an adjusted p-value <0.05 as the threshold and |log2FoldChange|>1 as the threshold. The expression profile-based immune cell levels were evaluated using the CIBERSORT algorithm.

[0066] After strict quality control screening, the cells were divided into 9 major cell types according to the expression of classic markers (such as Figure 1 E and Figure 2 The results showed that compared with the NDW group, the proportions of major cell types (such as fibroblasts, keratinocytes, and pericytes) in the skin tissue of the DW group were relatively reduced, while the proportion of infiltrating immune cells (especially monocytes and macrophages) increased (as shown in Figure 2). Figure 2 (as shown in F in the figure).

[0067] Furthermore, in order to determine the cellular origins of the above metabolic differential genes in the wound, this study conducted a cross-analysis of omics data and explored candidate genes with the same trends at the tissue and cell levels (e.g. Figure 1 F and Figure 2 The direction of change of the 23 candidate genes in tissues and their main differential cell sources are shown in Figure 2. Figure 1 As shown in G, the expression of some metabolic genes is significantly correlated with the tissue inflammatory macrophage infiltration score. Among them, methionine adenosyltransferase 2A (MAT2A) is mainly downregulated in pericytes, and its expression is most significantly negatively correlated with inflammatory macrophage infiltration. In addition, cell communication analysis results show that in the diabetic wound microenvironment, pericytes with low expression of MAT2A interact most closely with macrophages (e.g. Figure 1 H in the figure).

[0068] 3. Methionine cycle analysis Schematic diagram of the methionine cycle Figure 1 As shown in Figure 1, MAT2A is the rate-limiting enzyme in the methionine cycle and is involved in the synthesis of S-adenosylmethionine (SAM). Its substrate methionine accumulates in diabetic wounds, and among the metabolic enzymes involved in the methionine cycle, only the downregulation of MAT2A is statistically significant (e.g. Figure 1 (shown in J).

[0069] 4. Immunofluorescence staining analysis In order to detect the expression of CD31-NG2+PDGFRβ+ pericyte-related proteins in diabetic wounds, this study also performed immunofluorescence staining analysis. The specific methods are as follows: Cells were cultured in 35 mm confocal culture dishes and treated accordingly. After washing with PBS, cells were fixed in 4% paraformaldehyde for 15 minutes and then permeabilized in 0.3% Triton X-100 for 10 minutes at room temperature. After washing, cells were blocked with 6% fetal goat serum for 1 hour and then incubated with the indicated primary antibodies and fluorescently conjugated secondary antibodies. Confocal images were acquired using a confocal microscope (Zeiss LSM880 and Airyscan), and image analysis was performed using Zen version 2.6 or ImageJ software.

[0070] The results are as follows Figure 1 As shown in Figure 3K, the expression level of MAT2A is decreased in CD31-NG2+PDGFRβ+ pericytes in human wounds. In addition, pericytes with low MAT2A expression are less enriched during wound healing and regeneration (e.g. Figure 1 L in the figure).

[0071] The above data results indicate that there is a potential pathogenic association between the downregulation of pericyte MAT2A and the persistent inflammatory macrophage infiltration in refractory wounds.

[0072] Example 2: Effects of knocking out the pericyte MAT2A gene on macrophage phenotype and wound regeneration To gain a deeper understanding of the role of pericytes and downregulated MAT2A in wound regeneration, this example specifically knocked out the pericyte MAT2A gene to explore the effects of MAT2A on macrophage phenotype and wound regeneration.

[0073] 1. Construction of pericyte-specific MAT2A knockout mice NG2-CreERT2 mice were mated with MAT2Aflox / flox mice to generate pericyte-specific MAT2A knockout mice on a C57 background. Before wound modeling, all mice were given tamoxifen. The specific flow chart is shown in the figure. Figure 3 As shown in Figure A, the dosage of Tamoxifen is 100 mg / kg mouse body weight, and the drug is administered for 7 consecutive days, once a day, at the same time point. After the administration is completed, the mice are recommended to be kept for 7-14 days to allow Cre to have sufficient time to act and fully produce the cutting effect.

[0074] After the construction was completed, peripheral skin pericytes were isolated by immunomagnetic cell sorting and flow cytometry. The mouse pericyte isolation and cell culture methods were as follows: Pericytes were isolated from mouse skin. Briefly, skin tissue was thoroughly washed in PBS and manually minced into small pieces. The tissue suspension was then incubated with collagenase IV (2 mg / ml), DNase I (0.5 mg / ml), and hyaluronidase (0.002 mg / ml) on a shaker at 37°C for 2 hours. The cell mixture was filtered sequentially through 70 µm and 40 µm filters to obtain a single-cell suspension. Endothelial cells were removed using microspheres coated with anti-CD31 antibodies (Miltenyi Biotech) according to the manufacturer's protocol. Remaining cells were further purified using microspheres coated with anti-NG2 antibodies. Isolated pericytes were cultured in pericyte medium supplemented with 1% pericyte growth supplement, 2% fetal bovine serum (FBS), and 1% penicillin-streptomycin and passaged to new culture dishes when adherent colonies reached approximately 70–80% confluence. Isolated pericytes were identified by flow cytometry before use. Pericytes used in all experiments were at passages 2–5. The remaining cell types used in this study were cultured according to established protocols outlined in previous studies. All cells were authenticated as free of mycoplasma contamination.

[0075] Identification results such as Figure 3 B and Figure 4As shown in A and B, MAT2A is specifically deleted in pericytes, indicating that MAT2A knockout is successful.

[0076] 2. Impact on wound healing speed This study further established a surgical excisional wound model. The specific method was as follows: mice were anesthetized, the dorsal hair was removed, the area was irrigated with sterile water, and a full-thickness dorsal wound was created using a 10 mm punch biopsy.

[0077] After construction, representative images of the mouse skin wounds were collected on days 0, 4, 8, 12, and 16. ImageJ software was used to quantitatively analyze the wound size ratio, and the ratio of wound closure rate to wound size on day 0 was calculated. There were 12 cases in each group. Representative blood perfusion images of the wounds were also collected on days 4 and 8 after surgery for statistical analysis.

[0078] The results are as follows Figure 3 As shown in Figures C and D, MAT2A loss of function (LOF) leads to slower wound healing and decreased blood perfusion at the skin surface.

[0079] 3. Histological staining analysis Skin wound sections were stained with HE, Masson's trichrome, and immunohistochemically for Ki-67, α-SMA, and IL6, as described in detail in the art.

[0080] Specimens were collected on day 8 after wound model preparation. N = 3 mice were used for sampling at the indicated time points. Scale bar, 100 μm. Histological staining results are shown in Figure 3 E and Figure 4 As shown in Figure 3C, the epidermis of the pericyte-MAT2A deficiency group was thinner, with a lower proportion of Ki-67-positive cells, less α-SMA aggregation, and higher IL6 expression levels.

[0081] 4. Single-cell transcriptome analysis To comprehensively determine the potential impact of MAT2A on the wound microenvironment, this study performed single-cell transcriptome analysis on wound edge tissues from the MAT2A LOF group (n = 3) and the control group (n = 3). The specific methods are as follows: Wound margin tissue from Mat2a- / - and wild-type mice (n = 3) was digested and analyzed. The cell suspension was loaded onto the GemCode single-cell instrument, which generates single-cell gel beads (Gel Bead-In-EMlusion, GEMs). scRNA-seq libraries were constructed using the 10X Genomics Chromium Next GEM Single Cell 3' Kit. Barcoded full-length cDNA was reverse-transcribed from polyadenylated mRNA. Residual biochemicals and primers were removed from the post-GEM reaction mixture using silane magnetic beads. The full-length barcoded cDNA was then PCR-amplified to obtain sufficient material for library construction. Final libraries were quantified prior to Illumina bridge amplification, and all libraries were sequenced at 150 bp paired-end on an Illumina sequencer.

[0082] scRNA-seq raw reads in FASTQ format were processed using CellRanger v8.0.0 (10X Genomics) and aligned to the mm10 reference genome using default parameters to generate filtered gene expression matrices and .bam files. Quality control and scRNA data analysis were performed using the Seurat R package (version 4.4.0). Cells expressing more than 200 genes and genes expressed in more than three cells were obtained for further study. Low-quality cells were excluded according to the following criteria: (1) <200 expressed genes, (2) >7500 expressed genes, and (3) >15% of UMIs were derived from mitochondrial DNA.

[0083] scRNA-seq count data were log-normalized and scaled to 10,000 reads per cell using the NormalizeData function. 2,000 highly variable genes (HVGs) were identified in cells using the FindVariableFeatures function, and gene expression levels were scaled and centered using the ScaleData function. Principal component analysis (PCA) dimensionality reduction was performed on the HVGs using the RunPCA function. Batch effects were subsequently removed, and the merged Seurat objects were integrated using Harmony (version 1.2.0). Cells were clustered and visualized in two-dimensional space using the FindNeighbors and FindClusters functions at a cluster resolution of 0.7, resulting in the identification and visualization of 37 clusters. The FindAllMarkers function with default parameters was used to identify specific marker genes for each cluster. Finally, the cell clusters were annotated using cluster-specific marker genes and classical cell markers from the CellMarker database (http: / / 117.50.127.228 / CellMarker / ). The main cell types were extracted from the integrated dataset for analysis, and data preprocessing was performed as described above. Differentially expressed genes (DEGs) between the two groups were identified using the FindMarkers function and the Wilcoxon rank sum test, with an average log2-fold change of 0.25, an adjusted p-value of 0.05, and a minimum pct of 0.1.

[0084] After quality control of the raw data (e.g. Figure 5 As shown in A in the figure, 67,945 cells were screened in this experiment, of which 27,106 expressed genes were used for further analysis in Seurat. Based on the expression of classic markers, the cells were divided into 12 major cell types using uniform manifold approximation and projection (UMAP), including pericytes, keratinocytes, lymphocytes, lymphatic endothelial cells (Lyen), muscle cells, capillary cells, Schwann cells, endothelial cells, macrophages, neutrophils, and fibroblasts (as shown in Figure 2). Figure 3 F and Figure 5 In the MAT2A LOF group (i.e., MAT2A knockout group), the abundance of major tissue cells, including fibroblasts, pericytes, and endothelial cells, was reduced. In contrast, the infiltration of immune cells such as neutrophils, lymphocytes, and macrophages increased (e.g., Figure 3 MAT2A deficiency in pericytes leads to markedly altered gene expression patterns characterized by enhanced immune cell chemotaxis and reduced intrinsic angiogenic capacity (e.g., Figure 3 Furthermore, pericytes showed strong interactions with macrophages in the complex wound environment (e.g. Figure 3 After MAT2A ablation in pericytes, several pro-inflammatory genes (Ccl3, Il1b, and Nlrp3) were upregulated in macrophage clusters, whereas other anti-inflammatory genes (C1qa, C1qb, and Selenop) were downregulated in macrophage clusters, suggesting that MAT2A plays a key role in the potential crosstalk between pericytes and macrophages (e.g., Figure 3 K in the figure).

[0085] 5. Kinetic Analysis of Macrophages Macrophage phenotype plays an important role in the chronic inflammatory outcome of refractory wounds. This study investigated the intrinsic dynamics of macrophages, such as their trajectory and cell-cell communication. The specific methods are as follows: The Monocle 2 R package (version 2.32.0) was used to elucidate cell trajectories. A CellDataSet object was created using normalized counts and metadata, followed by dimensionality reduction using the DDRTree method. To visualize trajectories, the 'plot_cell_trajectory' function was executed.

[0086] To explore potential interactions between pericytes and other cell types, CellChat (version 1.6.1) was performed using the mouse database (CellChatDB.mouse) with default parameters and processes. The interaction strengths of pericytes with other cell types were visualized by netVisual_circle, and significant interactions of ligand-receptor pairs between pericytes and macrophage clusters were visualized by netVisual_bubble.

[0087] Macrophages were reclassified into 7 different subclusters (e.g. Figure 3 L and Figure 5 The results show that subclusters 1, 3, and 5 exhibited higher pro-inflammatory M1 macrophage characteristics, while subclusters 0, 2, and 4 exhibited anti-inflammatory M2 macrophage characteristics. It is worth noting that the ratio between these two categories is significantly unbalanced (as shown in Figure 5E). Figure 5 F in the figure).

[0088] Furthermore, trajectory analysis and quantitative evaluation results showed that in the MAT2A LOF group, Il1a hi Il1b hi The number of pro-inflammatory macrophages was mainly increased, while Cmss1 hi Camk1d hi and Lyve1 hi Selenophi Decreased numbers of anti-inflammatory macrophages (e.g. Figure 3 The imbalance between M1 and M2 macrophages was further verified by immunofluorescence staining (as shown in Figure 5A). Figure 3 N in the figure).

[0089] These data indicate that the loss of MAT2A in pericytes reduces wound blood perfusion, exacerbating the local inflammatory microenvironment and hindering wound regeneration. Furthermore, the researchers confirmed that the loss of MAT2A in pericytes upregulates pro-inflammatory genes (Ccl3, Il1b, and Nlrp3) in macrophage clusters, while downregulating other anti-inflammatory genes (C1qa, C1qb, and Selenop) in macrophage clusters, leading to an imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophages.

[0090] Example 3: Preparation and characterization of PMCNPs This example provides pericyte membrane-coated saMAT2A-loaded lipid nanoparticles (PMCNPs), which can target pericytes and promote wound regeneration. Specifically, the following is provided.

[0091] 1. Preparation of PMCNPs The preparation process and structural diagram of PMCNPs in this embodiment are as follows Figure 6 As shown in Figure A, saRNA is used to mediate the sustained expression of MAT2A, and the pericyte membrane is coated on lipid nanoparticles loaded with saMAT2A for targeted delivery. The specific preparation process of PMCNPs is as follows.

[0092] (1) Self-amplifying RNA synthesis: VectorBuilder software was used to synthesize self-amplified RNA of the MAT2A gene. Specifically, the coding sequence of interest was first inserted into the pmRVac vector using the Gibson Assembly method to generate a DNA template for in vitro transcription. The pmRVac vector contains a T7 promoter sequence, a 5' UTR, a 3' UTR, a 110 nt segmented poly A and a SapI The restriction endonuclease site is inserted between the UTRs. The recombinant vector is transformed into E. coli. After positive screening, the plasmid is extracted and purified, and then used SapI The restriction endonuclease is used to linearize the DNA to obtain a linear DNA template.

[0093] The linear DNA template was mixed with T7 RNA polymerase, nucleoside triphosphates (NTPs), and a magnesium-containing buffer to establish an in vitro transcription reaction. The reaction mixture was incubated at 37°C for 2 hours to generate Mat2a mRNA via T7 in vitro transcription. The resulting mRNA (i.e., saRNA) was then enzymatically capped and methylated. The isolated mRNA was eluted with an acidic buffer and stored at -80°C. mRNA concentration and purity were determined by UV-visible spectrophotometry, and its integrity was verified by denaturing agarose gel analysis.

[0094] The sequence information of Mat2a mRNA is as follows:

[0095] (2) Synthesis of lipid nanoparticles: The ionizable cationic lipid SM-102, the auxiliary lipid DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine), cholesterol, and the PEG2000-DMG PEG-containing lipid were dissolved in ethanol at a molar ratio of 50:10:38.5:1.5 to prepare a lipid solution. Simultaneously, the mRNA was diluted to 1 mg / mL in sodium citrate acidified buffer to prepare an mRNA solution. The lipid solution and mRNA solution were mixed at a 1:1 ratio using a microfluidic mixer. The mixture was then dialyzed against 87 mg / mL sucrose in Tris-HCl buffer using a dialysis bag and passed through a 0.22 μm filter to obtain lipid nanoparticles (labeled as LNP-MAT2A-saRNA).

[0096] (3) Cell membrane encapsulation: The encapsulation of the cell membrane is achieved by the extrusion method, which specifically includes the following steps: S1. Prepare pericyte membrane fragments at a concentration of 1 mg / mL according to known methods.

[0097] S2. The prepared pericyte membrane fragments were evenly mixed with the above-mentioned lipid nanoparticles in deionized water, where the cell membrane concentration was 1 mg / mL; the mixture was then continuously passaged through an Avanti liposome extruder equipped with different pore sizes (0.8 μm, 0.45 μm, 0.45 μm, 0.2 μm) to obtain cell membrane-coated nanomaterials, namely pericyte membrane-coated saMAT2A-loaded lipid nanoparticles (labeled as PMCNPs).

[0098] 2. Average particle size and zeta potential determination The potential and particle size of the prepared PMCNPs and pericyte membrane vesicles (PM) were measured using a nano-laser particle size analyzer, and the morphology of the obtained lipid nanoparticle materials was examined using a transmission electron microscope (TEM).

[0099] The results of the determination of the average diameter and zeta potential of PMCNPs are shown in Figure 2. Figure 6 As shown in Figures B and C, the hydrodynamic diameter of pericyte membrane-coated nanoparticles (PMCNPs) increased by approximately 18 nm compared to pericyte membrane vesicles, and the zeta potential increased, indicating that the LNP-saRNA complex was successfully encapsulated within the pericyte membrane. Furthermore, transmission electron microscopy imaging confirmed that PMCNPs exhibited a uniform "core-shell" morphology (e.g., Figure 6 (as shown in D in the figure).

[0100] 3. Stability testing The storage stability of the PMCNPs and pericyte membrane vesicles (PMs) prepared above was tested. They were stored at room temperature for 5, 10, 15, 20 and 25 h, respectively, and the changes in the hydrodynamic diameter were observed and statistically analyzed.

[0101] The results are as follows Figure 6 As shown in FIG. 8E , the PMCNPs prepared in the present invention exhibit excellent stability after long-term storage at room temperature.

[0102] Example 4: In vitro cell experiment This example explores the interaction between PMCNPs and pericytes by delivering the PMCNPs prepared in Example 3 above to pericytes. The specific contents are as follows: 1. Optimal dose screening The dose-effect relationship between PMCNPs and pericytes was studied using the following methods: Different concentrations of saMAT2A were added to the culture medium to observe the optimal concentration that could achieve stable and maximized expression for 24 hours.

[0103] The results are as follows Figure 6 F and Figure 7 As shown, administration of saMAT2A at a concentration of 500 ng / ml effectively maximized MAT2A expression in pericytes within 24 hours, and this dose maintained stable expression for at least 1 week after treatment.

[0104] 2. Targeted delivery efficiency of cells from different wound sources PMCNPs were administered to wound-derived cells (such as pericytes, fibroblasts, and endothelial cells).

[0105] The results are as follows Figure 8 As shown, PMCNPs exhibited excellent efficiency in specific delivery to pericytes, while only weak signals of MAT2A expression were observed in fibroblasts and endothelial cells, indicating that PMCNPs had good targeted delivery efficiency to pericytes.

[0106] Example 5: In vivo experiments This example demonstrates the feasibility and safety of targeted wound treatment with the prepared PMCNPs. Specifically, this example administered PMCNPs to non-diabetic and diabetic wound model mice, and statistically analyzed the wound repair results, including the following:

[0107] 1. Construction of non-diabetic and diabetic wound mouse models Diabetic or non-diabetic mice were anesthetized, their dorsal hair removed, and the area irrigated with sterile water. A full-thickness dorsal wound was created using a 10 mm punch biopsy to establish a wound model in mice.

[0108] 2. Medication treatment PMCNPs were administered at a concentration of 500 ng / mL on days 1 and 7 after wound establishment ( Figure 6 G in ).

[0109] 3. Observation of skin wound closure Representative images of mouse skin wounds were collected on days 0, 4, 8, 12, and 16 after surgical wound excision. Wound size ratios were quantified using ImageJ software and calculated as the percentage of wound closure compared to wound size on day 0. N = 12 per group. Representative blood perfusion images and statistical analysis were performed on days 4 and 8 after surgery (n = 3).

[0110] The results are as follows Figure 6 As shown in Figures H and I, diabetic wounds treated with PMCNPs had significantly accelerated healing compared to non-diabetic wounds, and also showed enhanced blood perfusion in the affected area.

[0111] 4. Histological Analysis Skin wound sections were stained with H&E and Masson's trichrome, and immunohistochemical staining was performed for Ki-67, α-SMA, and IL-6. Samples were collected on day 8 after wound model creation. N = 3 mice were sampled at the indicated time points. Scale bar, 100 μm.

[0112] The results of histological analysis were as follows Figure 6 J and Figure 9 As shown, the epidermis was thicker, the collagen volume fraction was increased, the proportion of Ki-67 positive cells was higher, the expression level of α-SMA was enhanced, and the accumulation of the proinflammatory factor IL6 in the tissue of the treatment group was less than that of the control group.

[0113] 5. Flow cytometry analysis Flow cytometry analysis of skin wound macrophages on days 4 and 8 was performed. The specific method is as follows: Before surface staining with antibodies, the samples were incubated with anti-mouse CD16 / 32 antibodies (Biolegend) for 10 minutes to block Fc-γ receptors. Subsequently, cells were stained with fluorescent antibodies specific for the corresponding surface proteins for 20 minutes on ice. After washing, cells were analyzed using a FACS Canto II cell analyzer (BD Biosciences). Data were processed using FlowJo 10 software.

[0114] Flow cytometry analysis results Figure 6As shown in Figure ​K, it shows that the intensity of CD86 labeling (indicating pro-inflammatory macrophage activity) was reduced in diabetic wounds treated with PMCNPs compared with the untreated diabetic group.

[0115] 6. Immunofluorescence staining Immunofluorescence staining was performed to observe macrophage infiltration in skin wounds on day 8. N = 3 animals per group. Scale bar, 20 μm.

[0116] Immunofluorescence staining results Figure 6 As shown in L, on day 8, the number of pro-inflammatory macrophages decreased and the number of anti-inflammatory macrophages increased.

[0117] 7. Physiological index detection Peripheral blood glucose levels, food intake, and body weight were measured in diabetic mice treated with and without PMCNPs. H&E staining was performed on the lungs, heart, kidneys, liver, muscles, and spleen of diabetic mice treated with PMCNPs.

[0118] Peripheral blood glucose level, food intake and body weight test results Figure 10 As shown in the results, no significant changes in blood glucose levels, food intake, or body weight that could be directly attributed to PMCNPs intervention were detected. In addition, no significant histological changes were observed in the lung, heart, kidney, liver, muscle, and spleen (e.g. Figure 11 shown).

[0119] The above results show that the MAT2A-targeted treatment strategy can significantly accelerate the healing rate, reduce the number of pro-inflammatory macrophages, and reduce the accumulation of pro-inflammatory factors without affecting the functions of other organs and is highly safe.

[0120] In summary, the present invention provides the use of methionine adenosyltransferase 2A and related substances in the preparation of wound repair products. First, by studying the metabolic regulatory network in diabetic wounds, the present invention found that the downregulated MAT2A expression in pericytes was significantly negatively correlated with the infiltration of M1 macrophages, and observed that the pericyte-specific deletion of MAT2A in wounds would lead to delayed wound healing, accompanied by an increase in inflammatory macrophage infiltration. Pericytes are an important component of angiogenesis. In vivo experiments showed that the blood perfusion of the wound in the MAT2A-deficient group was reduced, suggesting that the downregulated expression of MAT2A in pericytes may have a potential pathogenic relationship with the microcirculation disorder in diabetic wounds.

[0121] Furthermore, the present invention provides saMAT2A-loaded pericyte membrane-coated lipid nanoparticles (PMCNPs), which have strong targeting properties for diabetic pericytes and stably express MAT2A. In a diabetic mouse wound model, treatment with PMCNPs significantly enhanced wound regeneration, reduced persistent inflammatory macrophage infiltration in diabetic wounds, and promoted microcirculatory recovery. This suggests that substances expressing the MAT2A gene have promising application prospects in promoting wound repair.

[0122] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. Use of at least one of A1) to A4) in the preparation of a wound repair product; A1) MAT2A protein; A2) Substances that increase the activity of MAT2A protein; A3) substances that specifically express MAT2A protein; A4) Substances that promote MAT2A gene expression.

2. The use according to claim 1, characterized in that The substance that increases the activity of the MAT2A protein includes at least one of a small molecule compound, an antibody, a peptide, a carbohydrate or a virus; And / or, the substance that specifically expresses MAT2A includes at least one of the following: B1) a nucleic acid molecule encoding the MAT2A protein; B2) an expression cassette, vector or transgenic cell line comprising the nucleic acid molecule described in B1); And / or, the substance that specifically promotes MAT2A gene expression includes at least one of a nucleic acid drug containing a promoter or enhancer of MAT2A expression, a small molecule agonist or a polypeptide agonist that promotes the expression of a gene encoding MAT2A protein.

3. The use according to claim 2, characterized in that The nucleic acid molecule comprises at least one of DNA, mRNA, circRNA or saRNA.

4. The use according to claim 1, characterized in that The wound repair includes diabetic wound repair and non-diabetic wound repair.

5. The use according to any one of claims 1 to 4, characterized in that The functions of the wound repair product include any one of C1) to C4): C1) Promote wound healing; C2) Increase blood perfusion at the skin surface; C3) increasing the proportion of Ki-67 positive cells and / or increasing the expression level of α-SMA; C4) Reduce the content of pro-inflammatory factors and / or increase the number of anti-inflammatory macrophages.

6. Application of MAT2A gene as a marker in the preparation and screening of candidate compounds for wound repair.

7. A lipid nanoparticle, characterized in that The preparation raw material comprises lipids and at least one of A1) to A4); A1) MAT2A protein; A2) Substances that increase the activity of MAT2A protein; A3) substances that specifically express MAT2A protein; A4) Substances that promote MAT2A gene expression.

8. The lipid nanoparticle according to claim 7, characterized in that The lipid comprises at least one of an ionizable cationic lipid, an auxiliary lipid, cholesterol, and a PEGylated lipid; Preferably, the lipid nanoparticles are coated with a cell membrane.

9. A wound repair drug, characterized in that: Comprising at least one of A1) to A4) or any one of the lipid nanoparticles according to any one of claims 7 to 8; A1) MAT2A protein; A2) Substances that increase the activity of MAT2A protein; A3) substances that specifically express MAT2A protein; A4) Substances that promote MAT2A gene expression.

10. The wound repair medicine according to claim 9, characterized in that: The drug further comprises pharmaceutically acceptable excipients.

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