Proteo-lipid vehicles formulated with fusion-associated small transmembrane (FAST) proteins for administration of leptin

Abstract

Provided here are compositions for delivery of leptin to a cell. The compositions can comprise a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof. Also provided are methods for using the compositions.

Description

PROTEO-LIPID VEHICLES FORMULATED WITH FUSION-ASSOCIATED SMALL TRANSMEMBRANE (FAST) PROTEINS FOR ADMINISTRATION OF LEPTINCROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 677,235, filed July 30, 2024, which application is incorporated herein by reference.SEQUENCE LISTING

[0002] The present application is being filed along with a Sequence Listing in electronic format. The Sequence Listing is provided as a file entitled 062548- 505001 WO_seqs. xml, created July 22, 2025, which is 19,572 bytes in size. The information in the electronic format of the Sequence Listing is incorporated by reference in its entirety.FIELD

[0003] The present disclosure relates to generally relates to compositions for molecular cargo delivery, and methods of use. The present disclosure provides compositions and methods for the administration of leptin.BACKGROUND

[0004] Leptin is a hormone related to the regulation of energy homeostasis. It is primarily produced by the adipose tissue and exerts its biological activities through binding to leptin receptors in the brain and peripheral organs.

[0005] One function of leptin can be to signal starvation. Deficiency in leptin can result in hyperphagia, which in turn can lead to obesity, and other metabolic disturbances. Leptin replacement therapy (e.g. metreleptin, a recombinant human leptin analog) may provide some benefits, but has a short half life of less than 5 hours and may require daily injection. There remains a need for improved compositions and methods to deliver leptin.SUMMARY

[0006] Disclosed herein are compositions and methods for delivering leptin or functional fragment thereof.

[0007] In one aspect, provided herein is a composition comprising a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof. In some embodiments, the FAST polypeptide comprises a p10 FAST protein, a p13 FAST protein, a p14 FAST protein, a p15 FAST protein, a p16 FAST protein, or a p22 FAST protein, or a fragment thereof. In some embodiments, the FAST polypeptide comprises a fusion proteincomprising a p14 ectodomain and a p15 endodomain. In some embodiments, the FAST polypeptide comprises a p14 transmembrane domain or a p15 transmembrane domain, or a fragment thereof.

[0008] In some embodiments, the nucleic acid comprises DNA. In some embodiments, the nucleic acid comprises a plasmid. In some embodiments, the nucleic acid comprises a mRNA. In some embodiments the leptin is human leptin. In some embodiments, the leptin includes an amino acid sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 16 or 17.

[0009] In one aspect, provided herein is a method of delivering a nucleic acid encoding leptin or a functional fragment thereof to a cell, comprising contacting the cell with a proteo- lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and said nucleic acid.

[0010] In another aspect, provided herein is a method of increasing expression of leptin in a cell, comprising contacting the cell with a proteo-lipid vehicle (PLV) comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin.

[0011] In another aspect, provided herein is a method of treating a metabolic disease, or inducing or maintaining weight loss in a subject in need thereof, comprising administering a proteo-lipid vehicle (PLV) comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject.

[0012] In some embodiments, the metabolic disease relates to leptin deficiency. In some embodiments, the metabolic disease is lipodystrophy or obesity.

[0013] In another aspect, provided herein is a method of treating leptin deficiency in a subject in need thereof, comprising administering a proteo-lipid vehicle (PLV) comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject.

[0014] In another aspect, provided herein is a method of increasing blood leptin levels in a subject in need thereof, comprising administering a proteo-lipid vehicle (PLV) comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin to the subject.

[0015] In another aspect, provided herein is a method of treating lipodystrophy in a subject in need thereof, comprising administering a proteo-lipid vehicle (PLV) comprising arecombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject.

[0016] In some embodiments, administering the proteo-lipid vehicle results in delivery of the nucleic acid to a cell of the subject. In some embodiments, delivery of the nucleic acid to the cell results in an increase in leptin expression in the cell. In some embodiments, delivery of the nucleic acid to the cell results in expression of leptin or a functional fragment thereof in the cell. In some embodiments, the expressed leptin or functional fragment thereof is secreted by the cell.

[0017] In some embodiments, the cell is an adipocyte. In some embodiments, the cell is a white adipocyte.

[0018] In some embodiments, delivering leptin or a functional fragment thereof to the cell comprises in vivo delivery. In some embodiments, delivering the nucleic acid comprises intravenous delivery or an injection.

[0019] In some embodiments, administering the proteo-lipid vehicle results in improved insulin sensitivity in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in lower fasting insulin levels in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in lower HbA1c levels in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in lower hepatic triglyceride levels in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in lower blood triglyceride levels in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in reduced food consumption in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in reduced weight gain in the subject relative to a baseline measurement or control. In some embodiments, administering the proteo-lipid vehicle results in at least 1% weight loss in the subject. In some embodiments, administering the composition results in stabilized blood glucose levels in the subject relative to a baseline measurement or control.

[0020] Other features and advantages of the present disclosure will become apparent from the following detailed description. The detailed description and the specific examples while indicating embodiments of the disclosure are given by way of illustration only. These detailed description and specific examples are provided for the purposes of explanation, and not limitation, of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Fig. 1 is a schematic of an example cargo delivery by a proteo-lipid vehicle (PLV) comprising FAST protein to a cell (e.g. a cell of a subject administered the PLV, or administered a composition comprising the PLV).

[0022] Fig. 2 is a graph showing durable expression with PLV-leptin in blood samples of subjects for 58 days following administration.

[0023] Fig. 3 is a graph showing 30% less weight gain with PLV-leptin, compared to subjects administered a PLV-control.

[0024] Fig. 4 is a graph showing 35% less food consumption of PLV-leptin, compared to PLV-control.

[0025] Fig. 5 is a graph of blood glucose measurements showing PLV-leptin restores glucose homeostasis.

[0026] Fig. 6 is an image showing leptin gene therapy reverses ob / ob (leptin KO) mouse morphology.

[0027] Fig. 7 is a plot showing body weights of mice treated with a PLV encoding leptin or a control, over a 172 day period.

[0028] Fig. 8 is a plot showing circulating leptin measurements of mice treated with a PLV encoding leptin or a control, over a 172 day period.

[0029] Fig. 9A includes images of histology where liver oil red was used.

[0030] Fig. 9B is a plot showing lipid droplet quantification from oil red histology images.

[0031] Fig. 10 is a plot showing liver weights of mice treated with a PLV encoding leptin or a control, at study day 172 following treatment.

[0032] Fig. 11 is a plot showing triglyceride measurements in liver tissue from mice treated with a PLV encoding leptin or a control, at study day 172.

[0033] Fig. 12 is a plot showing body weights of mice treated with a PLV encoding leptin or a control, for over 100 days after treatment.

[0034] Fig. 13 is a plot showing blood glucose measurements of mice treated with a PLV encoding leptin or a control, for over 100 days after treatment.

[0035] Fig. 14 includes images of ob / ob mice after treatment with a PLV encoding leptin or a control.

[0036] Fig. 15 is a plot of leptin measurements in blood samples of mice treated with a PLV encoding leptin or a control.

[0037] Fig. 16 is a plot of ob / ob mouse body weights after treatment with a PLV encoding leptin or a control, showing weight loss in mice that received the leptin DNA.

[0038] Fig. 17 is a plot of blood glucose measurements in ob / ob mice after treatment with a PLV encoding leptin or a control.

[0039] Fig. 18 includes images of a mouse treated with a control PLV on the left side of the figure, and an ob / ob mouse that lost weight upon treatment with a PLV encoding leptin on the right side of the figure.DETAILED DESCRIPTION

[0040] Disclosed herein are compositions and methods that include a fusion- associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin.

[0041] The following is a detailed description provided to aid those skilled in the art in practicing the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the disclosure. All publications, patent applications, patents, figures and other references mentioned herein are expressly incorporated by reference in their entirety.

[0042] All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.

[0043] For example, in the following passages, different aspects of the disclosure are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary.I. Compositions

[0044] Disclosed herein, in some embodiments, are compositions that include proteo- lipid vehicles (PLVs). The composition may include a lipid. The composition may include lipids. The composition may include a fusion-associated small transmembrane (FAST) polypeptide. A PLV may include a lipid or lipids, as well as a FAST protein. The composition may include a nucleic acid encoding leptin. The composition may include a nucleic acid encoding leptin or a functional fragment thereof. A PLV may include a nucleic acid encoding leptin, a lipid or lipids, and a FAST protein. The composition may be a pharmaceutical composition. The composition may be useful in a method herein.

[0045] Provided herein are compositions and methods for delivering leptin or functional fragment thereof. The composition may include lipids. The lipids may include acationic lipid, a helper lipid, an ionizable lipid, polyethylene glycol (PEG) or a PEGylated lipid, cholesterol, or a combination thereof. The composition may include a recombinant fusion- associated small transmembrane (FAST) polypeptide. The composition may include a nucleic acid encoding leptin or functional fragment thereof. Some embodiments relate to or include a PLV shown in Fig. 1.

[0046] In one aspect, provided herein is a composition comprising a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof. In one aspect, provided herein is a composition. The composition may comprise a proteo-lipid vehicle. The proteo-lipid vehicle may comprise a recombinant fusion-associated small transmembrane (FAST) polypeptide. The composition may comprise a nucleic acid. The nucleic acid may encode a leptin or a functional fragment thereof.

[0047] In some embodiments, the composition includes an N:P ratio. An N:P ratio may describe a stoichiometry between protonatable nitrogen (N) in a transfection or delivery reagent and anionic phosphate groups (P) in a nucleic acid. In some embodiments, the composition comprises a nucleic acid cargo and lipids at an N:P ratio of about 1 :1 to about 15:1. The N:P ratio may be about 1 :1 , about 2:1 , about 2.5:1 , about 3:1 , about 3.5:1 , about 4:1 , about 4.5:1 , about 5:1 , about 6:1 , about 7:1 , about 8:1 , about 9:1 , about 10:1 , about 11 :1 , about 12:1 , about 13:1 , about 14:1 , or about 15:1 , or a range defined by any 2 of the aforementioned ratios. The N:P ratio may be at least 1 :1 , at least 2:1 , at least 2.5:1 , at least 3:1 , at least 3.5:1 , at least 4:1 , at least 4.5:1 , at least 5:1 , at least 6:1 , at least 7:1 , at least 8:1 , at least 9:1 , at least 10:1 , at least 11 :1 , at least 12:1 , at least 13:1 , at least 14:1 , or at least 15:1. The N:P ratio may be less than 1 :1 , less than 2:1 , less than 2.5:1 , less than 3:1 , less than 3.5:1 , less than 4:1 , less than 4.5:1 , less than 5:1 , less than 6:1 , less than 7:1 , less than 8:1 , less than 9:1 , less than 10:1 , less than 11 :1 , less than 12:1 , less than 13:1 , less than 14:1 , or less than 15:1.

[0048] In some embodiments, the composition includes a nucleic acid cargo and a FAST protein at a FAST mucleic acid ratio. For example, 1 mg of DNA may be combined with about 25 pg of FAST protein. Such a combination may equate to a FAST :DNA ratio of about 1 :20 to 1 :50 (w / w). The FASTmucleic acid ratio may be about 1 :10 (w / w), about 1 :15 (w / w), about 1 :20 (w / w), about 1 :25 (w / w), about 1 :30 (w / w), about 1 :35 (w / w), about 1 :40 (w / w), about 1 :45 (w / w), about 1 :50 (w / w), about 1 :60 (w / w), about 1 :70 (w / w), about 1 :80 (w / w), about 1 :90 (w / w), or about 1 OO (w / w), or a range of any 2 of the aforementioned ratios. In some embodiments, the FASTmucleic acid ratio is at least 1 :10 (w / w), at least 1 :15 (w / w), at least 1 :20 (w / w), at least 1 :25 (w / w), at least 1 :30 (w / w), at least 1 :35 (w / w), at least 1 :40 (w / w), at least 1 :45 (w / w), at least 1 :50 (w / w), at least 1 :60 (w / w), at least 1 :70 (w / w), at least 1 :80(w / w), at least 1 :90 (w / w), or at least 1 :100 (w / w). In some embodiments, the FASTmucleic acid ratio is less than 1 :10 (w / w), less than 1 :15 (w / w), less than 1 :20 (w / w), less than 1 :25 (w / w), less than 1 :30 (w / w), less than 1 :35 (w / w), less than 1 :40 (w / w), less than 1 :45 (w / w), less than 1 :50 (w / w), less than 1 :60 (w / w), less than 1 :70 (w / w), less than 1 :80 (w / w), less than 1 :90 (w / w), or less than 1 OO (w / w). The FASTmucleic acid ratio may include a FAST:DNA ratio. The FASTmucleic acid ratio may include a FAST:RNA ratio.Lipids

[0049] Disclosed herein, in some embodiments, are compositions that include a lipid or lipids. The lipid or lipids may be used to deliver a nucleic acid encoding leptin to a cell. A composition herein, such as a vesicle, vehicle or proteo-lipid vehicle (PLV), may include a lipid. The composition may include lipids. The lipid or lipids may be purified. The lipid or lipids may be pharmaceutically acceptable.

[0050] Some embodiments include lipids at a lipid ratio (e.g. a molar lipid ratio), including a ratio or mole percentage of an ionizable lipid. The lipid ratio may include a number of moles of the ionizable lipid in relation to the other lipids. In some embodiments, the lipid ratio includes about 40-60 moles of the ionizable lipid. In some embodiments, the lipid ratio includes 40-60 moles of the ionizable lipid. In some embodiments, the lipid ratio includes about 45-55 moles of the ionizable lipid. In some embodiments, the lipid ratio includes 45-55 moles of the ionizable lipid. In some embodiments, the lipid ratio includes about 50 moles of the ionizable lipid. In some embodiments, the lipid ratio includes 50 moles of the ionizable lipid. In some embodiments, the lipid ratio includes 40, 41 , 42, 43, 44, 45, 46, 47, 48, 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, or 86 moles of the ionizable lipid, or a range of moles defined by any two of the aforementioned integers. In some embodiments, the lipids comprise or consist of 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 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%, or 86% ionizable lipid, or a range defined by any two of the aforementioned percentages of the ionizable lipid. The percentage or ratio of lipids that are ionizable lipid may be or include 1 ionizable lipid, or may be or include a combination (e.g. 2 or more) ionizable lipids. In some embodiments, the lipids comprise about 45-55% of the ionizable lipid. In some embodiments, the lipids comprise about 45% of the ionizable lipid. In some embodiments, the lipids comprise about 46% of the ionizable lipid. In some embodiments, the lipids comprise about 47% of the ionizable lipid. In some embodiments, the lipids comprise about 45% of the ionizable lipid. In some embodiments, the lipids comprise about 48% of the ionizable lipid. In some embodiments, the lipids comprise about 49% of the ionizable lipid. In some embodiments, thelipids comprise about 50% of the ionizable lipid. In some embodiments, the lipids comprise about 51% of the ionizable lipid. In some embodiments, the lipids comprise about 52% of the ionizable lipid. In some embodiments, the lipids comprise about 53% of the ionizable lipid. In some embodiments, the lipids comprise about 54% of the ionizable lipid. In some embodiments, the lipids comprise about 55% of the ionizable lipid. In some embodiments, the lipids comprise about 66% of the ionizable lipid. In some embodiments, the lipids comprise about 66% of the ionizable lipid. The lipid ratio or the lipid molar ratio may include at least one of the aforementioned percentages or amounts of ionizable lipid. The lipid ratio or the lipid molar ratio may include less than one of the aforementioned percentages or amounts of ionizable lipid.

[0051] Ionizable lipids may include lipids that can carry a charge depending on the pH. Examples of ionizable lipids include but are not limited to: 1 ,2-dioleoyl-3-dimethylammonium- propane (DODAP or DAP), 1 ,2-dioleyloxy-3-dimethylaminopropane (DODMA), or Dlin-MC3- DMA. In some embodiments, the ionizable lipid comprises 1 ,2-dioleoyl-3-dimethylammonium- propane (DODAP or DAP), 1 ,2-dioleyloxy-3-dimethylaminopropane (DODMA), or Dlin-MC3- DMA. In some embodiments, the ionizable lipid comprises DODAP. In some embodiments, the lipids comprise about 50% of DODAP. In some embodiments, the ionizable lipid comprises DODMA. In some embodiments, the ionizable lipid comprises Dlin-MC3-DMA.

[0052] Some embodiments include lipids at a lipid ratio (e.g. a molar lipid ratio), including a ratio or mole percentage of an helper lipid. The lipid ratio may include a number of moles of the helper lipid in relation to the other lipids. In some embodiments, the lipid ratio includes about 5-40 moles of the helper lipid. In some embodiments, the lipid ratio includes 5- 40 moles of the helper lipid. In some embodiments, the lipid ratio includes about 10-30 moles of the helper lipid. In some embodiments, the lipid ratio includes 10-30 moles of the helper lipid. In some embodiments, the lipid ratio includes about 15-28 moles of the helper lipid. In some embodiments, the lipid ratio includes 15-28 moles of the helper lipid. In some embodiments, the lipid ratio includes about 15 moles of the helper lipid. In some embodiments, the lipid ratio includes 15 moles of the helper lipid. In some embodiments, the lipid ratio includes about 20 moles of the helper lipid. In some embodiments, the lipid ratio includes 28 moles of the helper lipid. In some embodiments, the lipid ratio includes 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, or 40 moles of the helper lipid, or a range of moles defined by any two of the aforementioned integers. In some embodiments, the lipids comprise or consist of 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40% helper lipid, or a range defined by any two of the aforementioned percentages of the helper lipid. The percentage or ratio of lipids that are helper lipid may be or include 1 helperlipid, or may be or include a combination (e.g. 2 or more) helper lipids. In some embodiments, the lipids comprise about 5-40% of the helper lipid. In some embodiments, the lipids comprise about 5% of the helper lipid. In some embodiments, the lipids comprise about 10% of the helper lipid. In some embodiments, the lipids comprise about 11 % of the helper lipid. In some embodiments, the lipids comprise about 12% of the helper lipid. In some embodiments, the lipids comprise about 13% of the helper lipid. In some embodiments, the lipids comprise about 14% of the helper lipid. In some embodiments, the lipids comprise about 15% of the helper lipid. In some embodiments, the lipids comprise about 16% of the helper lipid. In some embodiments, the lipids comprise about 17% of the helper lipid. In some embodiments, the lipids comprise about 18% of the helper lipid. In some embodiments, the lipids comprise about 19% of the helper lipid. In some embodiments, the lipids comprise about 20% of the helper lipid. In some embodiments, the lipids comprise about 21% of the helper lipid. In some embodiments, the lipids comprise about 22% of the helper lipid. In some embodiments, the lipids comprise about 23% of the helper lipid. In some embodiments, the lipids comprise about 24% of the helper lipid. In some embodiments, the lipids comprise about 25% of the helper lipid. In some embodiments, the lipids comprise about 26% of the helper lipid. In some embodiments, the lipids comprise about 27% of the helper lipid. In some embodiments, the lipids comprise about 28% of the helper lipid. In some embodiments, the lipids comprise about 29% of the helper lipid. In some embodiments, the lipids comprise about 30% of the helper lipid. In some embodiments, the lipids comprise about 31% of the helper lipid. In some embodiments, the lipids comprise about 32% of the helper lipid. In some embodiments, the lipids comprise about 33% of the helper lipid. In some embodiments, the lipids comprise about 34% of the helper lipid. In some embodiments, the lipids comprise about 35% of the helper lipid. The lipid ratio or the lipid molar ratio may include at least one of the aforementioned percentages or amounts of the helper lipid. The lipid ratio or the lipid molar ratio may include less than one of the aforementioned percentages or amounts of the helper lipid.

[0053] In some embodiments, the helper lipid comprises 2-dioleoyl-sn-glycero-3- phosphoethanolamine (DOPE) or 1 ,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). In some embodiments, the helper lipid comprises DOPE. In some embodiments, the helper lipid comprises DSPC. In some embodiments, the lipids comprise about 28% of DOPE. In some embodiments, the lipids comprise about 20% of DOPE. In some embodiments, the lipids comprise about 15% of DSPC.

[0054] Some embodiments include lipids at a lipid ratio (e.g. a molar lipid ratio), including a ratio or mole percentage of cholesterol. The lipid ratio may include a number of moles of cholesterol in relation to the other lipids. In some embodiments, the lipid ratio includes about 0-30 moles of the cholesterol. In some embodiments, the lipid ratio includes 0-30 moles of the cholesterol. In some embodiments, the lipid ratio includes about 0-20 moles of thecholesterol. In some embodiments, the lipid ratio includes 0-20 moles of the cholesterol. In some embodiments, the lipid ratio includes about 0-15 moles of the cholesterol. In some embodiments, the lipid ratio includes 0-15 moles of the cholesterol. In some embodiments, the lipid ratio includes about 10-15 moles of the cholesterol. In some embodiments, the lipid ratio includes 10-15 moles of the cholesterol. In some embodiments, the lipid ratio includes about 0 moles of the cholesterol. In some embodiments, the lipid ratio includes 0 moles of the cholesterol. In some embodiments, the lipid ratio includes about 10 moles of the cholesterol. In some embodiments, the lipid ratio includes 10 moles of the cholesterol. In some embodiments, the lipid ratio includes about 15 moles of the cholesterol. In some embodiments, the lipid ratio includes 15 moles of the cholesterol. In some embodiments, the lipid ratio includes 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, or 30 moles of the cholesterol, or a range of moles defined by any two of the aforementioned integers. In some embodiments, the lipids comprise or consist of 0%, 1 %, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30% cholesterol, or a range defined by any two of the aforementioned percentages of the cholesterol. The percentage or ratio of lipids that are cholesterol may be or include 1 cholesterol, or may be or include a combination (e.g. 2 or more) cholesterols. In some embodiments, the lipids comprise about 0-30% of cholesterol. In some embodiments, the lipids comprise about 0-20% of cholesterol. In some embodiments, the lipids comprise about 0% of cholesterol. In some embodiments, the lipids comprise about 5% of cholesterol. In some embodiments, the lipids comprise about 6% of cholesterol. In some embodiments, the lipids comprise about 7% of cholesterol. In some embodiments, the lipids comprise about 8% of cholesterol. In some embodiments, the lipids comprise about 9% of cholesterol. In some embodiments, the lipids comprise about 10% of cholesterol. In some embodiments, the lipids comprise about 11% of cholesterol. In some embodiments, the lipids comprise about 12% of cholesterol. In some embodiments, the lipids comprise about 0% of cholesterol. In some embodiments, the lipids comprise about 13% of cholesterol. In some embodiments, the lipids comprise about 14% of cholesterol. In some embodiments, the lipids comprise about 15% of cholesterol. In some embodiments, the lipids comprise about 0% of cholesterol. In some embodiments, the lipids comprise about 16% of cholesterol. In some embodiments, the lipids comprise about 17% of cholesterol. In some embodiments, the lipids comprise about 18% of cholesterol. In some embodiments, the lipids comprise about 19% of cholesterol. In some embodiments, the lipids comprise about 20% of cholesterol. In some embodiments, the lipids comprise about 0% cholesterol. In some embodiments, the lipids comprise about 10% cholesterol. In some embodiments, the lipids comprise about 15% cholesterol. The lipid ratio or the lipid molar ratio may include at least one of the aforementioned percentages or amounts of the cholesterol. The lipid ratio or the lipid molarratio may include less than one of the aforementioned percentages or amounts of the cholesterol.

[0055] Some embodiments include lipids at a lipid ratio (e.g. a molar lipid ratio), including a ratio or mole percentage of an cationic lipid. The lipid ratio may include a number of moles of the cationic lipid in relation to the other lipids. In some embodiments, the lipid ratio includes about 10-60 moles of the cationic lipid. In some embodiments, the lipid ratio includes 10-60 moles of the cationic lipid. In some embodiments, the lipid ratio includes about 15-25 moles of the cationic lipid. In some embodiments, the lipid ratio includes 15-25 moles of the cationic lipid. In some embodiments, the lipid ratio includes about 18-20 moles of the cationic lipid. In some embodiments, the lipid ratio includes 18-20 moles of the cationic lipid. In some embodiments, the lipid ratio includes about 18 moles of the cationic lipid. In some embodiments, the lipid ratio includes 18 moles of the cationic lipid. In some embodiments, the lipid ratio includes about 20 moles of the cationic lipid. In some embodiments, the lipid ratio includes 20 moles of the cationic lipid. In some embodiments, the lipid ratio includes 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 , 52, 53, 54, 55, 56, 57, 58, 59, or 60 moles of the cationic lipid, or a range of moles defined by any two of the aforementioned integers. In some embodiments, the lipids comprise or consist of 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60% cationic lipid, or a range defined by any two of the aforementioned percentages of the cationic lipid. The percentage or ratio of lipids that are cationic lipid may be or include 1 cationic lipid, or may be or include a combination (e.g. 2 or more) cationic lipids. In some embodiments, the lipids comprise about 10-60% of the cationic lipid. In some embodiments, the lipids comprise about 15-25% of the cationic lipid. In some embodiments, the lipids comprise about 15% of the cationic lipid. In some embodiments, the lipids comprise about 16% of the cationic lipid. In some embodiments, the lipids comprise about 17% of the cationic lipid. In some embodiments, the lipids comprise about 18% of the cationic lipid. In some embodiments, the lipids comprise about 19% of the cationic lipid. In some embodiments, the lipids comprise about 20% of the cationic lipid. In some embodiments, the lipids comprise about 21% of the cationic lipid. In some embodiments, the lipids comprise about 22% of the cationic lipid. In some embodiments, the lipids comprise about 23% of the cationic lipid. In some embodiments, the lipids comprise about 24% of the cationic lipid. In some embodiments, the lipids comprise about 25% of the cationic lipid. The lipid ratio or the lipid molar ratio may include at least one of the aforementioned percentages or amounts of the cationic lipid. The lipid ratio or the lipid molarratio may include less than one of the aforementioned percentages or amounts of the cationic lipid.

[0056] Examples of cationic lipids include but are not limited to 1 ,2-dioleoyl-3- trimethylammonium-propane (DOTAP or TAP) and 1 ,2-di-O-octadecenyl-3- trimethylammonium propane (DOTMA). In some embodiments, the cationic lipid comprises 1 ,2-dioleoyl-3-trimethylammonium-propane (DOTAP or TAP) or 1 ,2-di-O-octadecenyl-3- trimethylammonium propane (DOTMA). In some embodiments, the cationic lipid comprises DOTAP. In some embodiments, the cationic lipid comprises DOTMA. In some embodiments, the lipids comprise DOTAP. In some embodiments, the lipids comprise about 20% DOTAP. In some embodiments, the lipids comprise about 18% DOTAP.

[0057] Some embodiments include a PEGylated lipid. For example, a lipid may include PEG. For example, the lipids may be PEGylated, or may include a combination of PEGylated lipids and at least one other type of lipid. A PEGylated lipid may include a PEG length or PEG size. For example, the PEGylated lipid may include 0.5-2 kDa PEG. In some embodiments, the PEG of a PEGylated lipid has a molecular mass of about 0.1 kDa, about 0.2 kDa, about 0.3 kDa, about 0.4 kDa, about 0.5 kDa, about 0.6 kDa, about 0.7 kDa, about 0.8 kDa, about 0.9 kDa, about 0.10 kDa, about 0.11 kDa, about 0.12 kDa, about 0.13 kDa, about 0.14 kDa, about 0.15 kDa, about 0.16 kDa, about 0.17 kDa, about 0.18 kDa, about 0.19 kDa, about 0.20 kDa, about 0.21 kDa, about 0.22 kDa, about 0.23 kDa, about 0.24 kDa, or about 0.25 kDa, or a range of masses defined by any 2 of the aforementioned masses. In some embodiments, the PEG of a PEGylated lipid has a molecular mass of at least 0.1 kDa, at least 0.2 kDa, at least 0.3 kDa, at least 0.4 kDa, at least 0.5 kDa, at least 0.6 kDa, at least 0.7 kDa, at least 0.8 kDa, at least 0.9 kDa, at least 0.10 kDa, at least 0.11 kDa, at least 0.12 kDa, at least 0.13 kDa, at least 0.14 kDa, at least 0.15 kDa, at least 0.16 kDa, at least 0.17 kDa, at least 0.18 kDa, at least 0.19 kDa, at least 0.20 kDa, at least 0.21 kDa, at least 0.22 kDa, at least 0.23 kDa, at least 0.24 kDa, or at least 0.25 kDa. In some embodiments, the PEG of a PEGylated lipid has a molecular mass of less than 0.1 kDa, less than 0.2 kDa, less than 0.3 kDa, less than 0.4 kDa, less than 0.5 kDa, less than 0.6 kDa, less than 0.7 kDa, less than 0.8 kDa, less than 0.9 kDa, less than 0.10 kDa, less than 0.11 kDa, less than 0.12 kDa, less than 0.13 kDa, less than 0.14 kDa, less than 0.15 kDa, less than 0.16 kDa, less than 0.17 kDa, less than 0.18 kDa, less than 0.19 kDa, less than 0.20 kDa, less than 0.21 kDa, less than 0.22 kDa, less than 0.23 kDa, less than 0.24 kDa, or less than 0.25 kDa.

[0058] Some embodiments include lipids at a lipid ratio (e.g. a molar lipid ratio), including a ratio or mole percentage of PEG (e.g. associated with a lipid) or a PEGylated lipid. The lipid ratio may include a number of moles of the PEGylated lipid in relation to the other lipids. In some embodiments, the lipid ratio includes about 1 -15 moles of the PEGylated lipid.In some embodiments, the lipid ratio includes 1 -15 moles of the PEGylated lipid. In some embodiments, the lipid ratio includes about 1 -4 moles of the PEGylated lipid. In some embodiments, the lipid ratio includes 1 -4 moles of the PEGylated lipid. In some embodiments, the lipid ratio includes about 2 moles of the PEGylated lipid. In some embodiments, the lipid ratio includes 2 moles of the PEGylated lipid. In some embodiments, the lipid ratio includes 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, or 15 moles of the PEGylated lipid, or a range of moles defined by any two of the aforementioned integers. In some embodiments, the lipids comprise or consist of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% PEGylated lipid, or a range defined by any two of the aforementioned percentages of the PEGylated lipid. The percentage or ratio of lipids that are PEGylated lipid may be or include 1 PEGylated lipid, or may be or include a combination (e.g. 2 or more) PEGylated lipids. In some embodiments, the lipids comprise about 1 -15% of the PEG. In some embodiments, the lipids comprise about 1 -8% of the PEG. In some embodiments, the lipids comprise about 1 -4% of the PEG. In some embodiments, the lipids comprise about 1% of the PEG. In some embodiments, the lipids comprise about 2% of the PEG. In some embodiments, the lipids comprise about 3% of the PEG. In some embodiments, the lipids comprise about 4% of the PEG. The lipid ratio or the lipid molar ratio may include at least one of the aforementioned percentages or amounts of the PEGylated lipid. The lipid ratio or the lipid molar ratio may include less than one of the aforementioned percentages or amounts of the PEGylated lipid.

[0059] In some embodiments, the PEG comprises an attached lipid. In some embodiments, the PEG is a PEGylated lipid. In some embodiments, the PEGylated lipid comprises 1 ,2-dimyristoyl-sn-glycero-3-methoxypolyethylene glycol-2000 (DMG-PEG). In some embodiments, the lipids comprise about 2% of DMG-PEG.

[0060] In some embodiments, the lipid ratio comprises about 66:30:4 moles of the ionizable lipid : helper lipid : PEG. In some embodiments, the lipid ratio comprises 66:30:4 moles of the ionizable lipid : helper lipid : PEG. In some embodiments, the lipid percentages are about 66:30:4 moles of the ionizable lipid : helper lipid : PEG. In some embodiments, the lipid percentages are 66:30:4 moles of the ionizable lipid : helper lipid : PEG.

[0061] A lipid may include a neutral lipid. The lipids may include neutral lipids. The lipid or lipids may be ionizable. The lipid or lipids may be ionized. A lipid may include a charged lipid. The lipids may include charged lipids. A charged lipid or lipid may be negatively charged. A charged lipid or lipid may be positively charged.

[0062] A composition herein may include a vehicle. A composition herein may include a proteo-lipid vehicle. A composition herein may include a vesicle. A vehicle may be or include a vesicle. A proteo-lipid vehicle may be or include a proteo-lipid vesicle.FAST proteins

[0063] Disclosed herein, in some embodiments, are compositions that include a fusion-associated small transmembrane (FAST) polypeptide. A FAST polypeptide may also be referred to as a FAST protein. A FAST protein may be combined with a lipid or lipids, e.g. as part of a composition. A FAST protein may be used to deliver a nucleic acid encoding leptin to a cell. A composition herein, such as a vesicle, vehicle or proteo-lipid vehicle (PLV), may include a FAST protein. The FAST protein may be purified. The FAST protein may be pharmaceutically acceptable.

[0064] In some embodiments, the composition further comprises a FAST polypeptide. In some embodiments, the composition comprises a recombinant FAST polypeptide. FAST proteins can share three common domains: A single transmembrane (TM) domain; an ectodomain; and an endodomain. The recombinant FAST polypeptide can be synthesized to combine the domains from different FAST proteins. The recombinant FAST polypeptide can comprise fragments of domains from the FAST proteins. The recombinant FAST polypeptide may include 1 , 2, or 3 of the domains. The recombinant FAST protein may include multiple domains from the same FAST protein, or may include multiple domains from different FAST proteins.

[0065] In some embodiments, the recombinant FAST polypeptide comprises a p10 FAST protein, a p13 FAST protein, a p14 FAST protein, a p15 FAST protein, a p16 FAST protein, or a p22 FAST protein, or a fragment thereof. In some embodiments, the FAST polypeptide comprises a p14 FAST protein, or a fragment thereof. In some embodiments, the FAST polypeptide comprises a p15 FAST protein, or a fragment thereof.

[0066] In some embodiments, the FAST polypeptide comprises a p14 ectodomain. In some embodiments, the FAST polypeptide comprises a p15 ectodomain. In some embodiments, the FAST polypeptide comprises a p14 TM domain. In some embodiments, the FAST polypeptide comprises a p15 TM domain. In some embodiments, the FAST polypeptide comprises a p14 endodomain. In some embodiments, the FAST polypeptide comprises a p15 endodomain. In some embodiments, the FAST polypeptide comprises a fusion protein comprising a p14 ectodomain and a p15 endodomain. In some embodiments, the FAST polypeptide comprises a p14 transmembrane domain or a p15 transmembrane domain, or a fragment thereof.

[0067] The recombinant FAST polypeptide can comprise functional variants of the domains. For example, substitutions within the p14 ectodomain such as V9I, P13A, GI4A and E15A may maintain fusion activity. As such, variation in the wild-type p14 ectodomain sequence can occur while maintaining functionality of the recombinant polypeptide.

[0068] The precise boundaries of the domains can vary. For example, the last two residues of a p14 ectodomain (e.g. amino acid chain WE) may be part of the transmembrane domain. The recombinant FAST polypeptide can comprise conservative amino acid substitutions.

[0069] In some embodiments, the recombinant FAST polypeptide comprises a sequence in Table 1. The sequence of the recombinant FAST polypeptide may be at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence in Table 1. In some embodiments, the sequence of the recombinant FAST polypeptide is less than 75%, less than 80%, less than 85%, less than 86%, less than 87%, less than 88%, less than 89%, less than 90%, less than 91%, less than 92%, less than 93%, less than 94%, less than 95%, less than 96%, less than 97%, less than 98%, less than 99%, or less than 100% identical to a sequence in Table 1. The recombinant FAST polypeptide may include a combination of sequences from Table 1 or variants herein.Table 1. Example FAST protein sequences

[0070] The FAST protein may be or include the amino acid sequence of SEQ ID NO: 1 . In some embodiments, the FAST protein includes or consists of a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 1 . The FAST protein may be or include the amino acid sequence of SEQ ID NO: 2. In some embodiments, the FAST protein includes or consists of a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 2. The FAST protein may be or include the amino acid sequence of SEQ ID NO: 3. In some embodiments, the FAST protein includes or consists of a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 3. The FAST protein may be or include the amino acid sequence of SEQ ID NO: 4. In some embodiments, the FAST protein includes or consists of a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 4. The FAST protein may be or include the amino acid sequence of SEQ ID NO: 5. In some embodiments, the FAST protein includes or consists of a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 5.

[0071] The different domains can be linked by one or more linkers. A linker can, for example, provide a structural function. The linker can comprise a peptide linker. An example of a linker includes glycine.

[0072] In some embodiments, the recombinant FAST polypeptide comprises an ectodomain. In some embodiments, the recombinant FAST polypeptide comprises a p14 ectodomain. In some embodiments, the recombinant FAST polypeptide comprises a p14 ectodomain or a fragment thereof. In some embodiments, the p14 ectodomain comprises an amino acid sequence of at least 80% sequence identity to SEQ ID NO: 6. some embodiments, the p14 ectodomain comprises an amino acid sequence of at least 85% sequence identity to SEQ ID NO: 6. In some embodiments, the p14 ectodomain comprises an amino acid sequence of at least 90% sequence identity to SEQ I D NO: 6. In some embodiments, the p14 ectodomain comprises an amino acid sequence of at least 95% sequence identity to SEQ ID NO: 6. Insome embodiments, the p14 ectodomain comprises an amino acid sequence of at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 6. In some embodiments, the p14 ectodomain comprises an amino acid sequence of SEQ ID NO: 6.

[0073] In some embodiments, the recombinant FAST polypeptide comprises a transmembrane domain (TMD). In some embodiments, the recombinant FAST polypeptide comprises a p14 transmembrane domain. In some embodiments, the recombinant FAST polypeptide comprises a p14 transmembrane domain or fragment thereof. In some embodiments, the recombinant FAST polypeptide comprises a p15 transmembrane domain. In some embodiments, the recombinant FAST polypeptide comprises a p15 transmembrane domain or fragment thereof. In some embodiments, the TMD comprises the amino acid sequence of SEQ ID NO: 7. In some embodiments, the TMD comprises an amino acid sequence at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, identical to SEQ ID NO: 7. In some embodiments, the TMD comprises the amino acid sequence of SEQ ID NO: 8. In some embodiments, the TMD comprises an amino acid sequence at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, identical to SEQ ID NO: 8.

[0074] In some embodiments, the recombinant FAST polypeptide comprises a p15 endodomain or a fragment thereof. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 80% sequence identity to SEQ ID NO: 9. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 85% sequence identity to SEQ ID NO: 9. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 90% sequence identity to SEQ ID NO: 9. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 95% sequence identity to SEQ ID NO: 9. In some embodiments, the p15 endodomain comprises an amino acid sequence of SEQ ID NO: 9. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 9.

[0075] In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 80% sequence identity to SEQ ID NO: 10. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 85% sequence identity to SEQ ID NO: 10. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 90% sequence identity to SEQ ID NO: 10. In some embodiments, the p15endodomain comprises an amino acid sequence of at least 95% sequence identity to SEQ ID NO: 10. In some embodiments, the p15 endodomain comprises an amino acid sequence of SEQ ID NO: 10. In some embodiments, the p15 endodomain comprises an amino acid sequence of at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 10.

[0076] The recombinant FAST polypeptide can comprise a tag such as an affinity tag. For example, the tag may include a HIS tag, a cMyc tag, or a FLAG tag. The tag may be useful for purification.

[0077] The recombinant FAST polypeptide may be prepared using in vivo or in vitro recombinant protein expression systems. In vivo expression systems comprise a host cell and a vector for expression in the host cell. The host is not particularly limited as long as the cell can express the recombinant FAST polypeptide. Prokaryotic and eukaryotic expression systems are available commercially. The selection of suitable system for expression of the recombinant FAST polypeptide is within the skill of one of ordinary skill in the art. The recombinant FAST polypeptide can, for example, be produced using an insect derived cell line (e.g. Sf9) and the Baculovirus expression system. After expression, the recombinant FAST polypeptide can be extracted and purified by methods known to one of ordinary skill in the art, such as affinity chromatography, size-exclusion chromatography, hydrophobic interaction chromatography, ion-exchange chromatography.

[0078] The recombinant FAST polypeptide may also be produced using a cell-free expression system. Such a system can comprise a nucleic acid (mRNA or DNA) that encodes the recombinant FAST polypeptide and a cell extract comprising molecules of the transcriptional and translational molecular machineries, such as RNA polymerases, ribosomes, tRNAs and amino acids, enzymatic cofactors etc. Cell-free protein expression systems are available commercially and can be used.Nucleic acids encoding leptin

[0079] Some embodiments relate to an nucleic acid. In some embodiments, the proteo-lipid vehicle comprises a nucleic acid. The nucleic acid may encode leptin or a functional fragment thereof. The nucleic acid may encode leptin or a functional fragment thereof. The nucleic acid may encode leptin. The nucleic acid may encode another nucleic acid. For example, the nucleic acid may include a deoxyribonucleic acid (DNA), and encode a ribonucleic acid (RNA). The nucleic acid can be a DNA, a ribonucleic acid (RNA), or a combination thereof. The nucleic acid may be included as part of a composition herein, for example, in combination with lipids and a fusion-associated small transmembrane (FAST) polypeptide. The leptin may be a recombinant peptide, or a nucleic acid encoding the leptinmay be recombinant. The nucleic acid may be purified. The nucleic acid may be pharmaceutically acceptable.

[0080] In some embodiments, the nucleic acid comprises a deoxyribonucleic acid (DNA). In some embodiments, the DNA comprises plasmid DNA (pDNA). In some embodiments, the DNA is or includes pDNA.

[0081] In some embodiments, the nucleic acid comprises a ribonucleic acid (RNA). In some embodiments, the RNA comprises a messenger RNA (mRNA). In some embodiments, the RNA is or includes mRNA. In some embodiments, the RNA comprises a modification.

[0082] Disclosed herein, in some embodiments, are nucleic acids. The nucleic acid may include an expression construct. An expression construct may include a promoter operably connected to a coding sequence. The expression construct may include a promoter. The expression construct may include a coding sequence. The expression construct may include further regulatory elements. The expression construct may include a polyA signal.

[0083] Disclosed herein, in some embodiments, are nucleic acids including a promoter. A nucleic acid encoding leptin may include a promoter. A nucleic acid encoding leptin may include a promoter. The promoter may be a mammalian promoter such as a human promoter or a mouse promoter. The promoter may include a leptin promoter. For example, the promoter may be a human leptin promoter. The promoter may be recombinant or transgenic. In some embodiments, the promoter is heterologous to a leptin coding sequence. In some embodiments, the promoter is heterologous to a naturally occurring leptin gene. The promoter may drive leptin expression.

[0084] In some embodiments, the promoter is a DNA promoter. In some embodiments, the promoter is an RNA promoter such as an mRNA promoter.

[0085] The promoter may be active in a eukaryotic cell. The promoter may be active in a mammalian cell. The promoter may be active in a human cell. The promoter may be active in a bacterial cell.

[0086] The promoter may be constitutive. A constitutive promoter may be active in adipose tissue. A constitutive promoter may be active in an adipose cell. A constitutive promoter may be active in an adipocyte. A constitutive promoter may be active in a white adipose tissue or white adipose cell.

[0087] The promoter may be tissue specific. For example, a tissue specific promoter may be adipose specific. In some embodiments, a tissue specific promoter is active in adipose tissue. A tissue specific promoter may be active in an adipose cell. A tissue specific promoter may be active in an adipocyte. A tissue specific promoter may be active in a white adipose tissue or white adipose cell.

[0088] A nucleic acid encoding leptin may include a coding sequence (CDS) encoding leptin (also referred to as a “leptin CDS”). Some embodiments include a leptin CDS. The leptin CDS may be driven or activated by a promoter herein.

[0089] In some embodiments, a promoter is operably connected to the leptin CDS. The promoter may be chemically or physically linked to a leptin-encoding gene. The promoter may be linked to a leptin CDS. For example, the promoter may be 5’ of a leptin CDS. In some embodiments, a promoter is 3’ of a leptin CDS. Some embodiments include another regulatory element, or a polyA signal 3’ of a leptin CDS.

[0090] Some embodiments relate to or include leptin or a functional fragment thereof. In some embodiments, the leptin or functional fragment thereof is leptin. Leptin may be or include human leptin. Leptin may be or include humanized leptin. In some embodiments, the leptin or functional fragment thereof is human leptin.

[0091] The nucleic acid may comprise a nucleic acid sequence of Table 2. The nucleic acid may encode a leptin with an amino acid sequence of Table 3. The nucleic acid may comprise a nucleic acid sequence of Table 2, and the nucleic acid may encode a leptin with an amino acid sequence of Table 3.Table 2. Example nucleic acids encoding leptinTable 3. Example leptin protein sequence

[0092] In some embodiments, the leptin CDS includes a nucleic acid sequence in Table 2. The leptin CDS sequence may be at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence in Table 2. In some embodiments, the leptin CDS sequence is less than 75%, less than 80%, less than 85%, less than 86%, less than 87%, less than 88%, less than 89%, less than 90%, less than 91%, less than 92%, less than 93%, less than 94%, less than 95%, less than 96%, less than 97%, less than 98%, less than 99%, or less than 100% identical to a sequence in Table 2. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0093] The nucleic acid encoding leptin may include the nucleic acid sequence of any one of SEQ ID NOs: 11 -15. In some embodiments, the nucleic acid encoding leptin includes a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to any one of SEQ ID NOs: 11-15. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0094] The nucleic acid encoding leptin may include the nucleic acid sequence of SEQ ID NO: 11. In some embodiments, the nucleic acid encoding leptin includes a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 11. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0095] The nucleic acid encoding leptin may include the nucleic acid sequence of SEQ ID NO: 12. In some embodiments, the nucleic acid encoding leptin includes a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 12. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0096] The nucleic acid encoding leptin may include the nucleic acid sequence of SEQ ID NO: 13. In some embodiments, the nucleic acid encoding leptin includes a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 13. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0097] The nucleic acid encoding leptin may include the nucleic acid sequence of SEQ ID NO: 14. In some embodiments, the nucleic acid encoding leptin includes a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 14. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0098] The nucleic acid encoding leptin may include the nucleic acid sequence of SEQ ID NO: 15. In some embodiments, the nucleic acid encoding leptin includes a sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 15. The nucleic acid may include DNA or RNA (e.g. plasmid DNA or mRNA).

[0099] In some embodiments, the leptin includes an amino acid sequence in Table 3. The leptin amino acid sequence may be at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence in Table 3. In some embodiments, the leptin amino acid sequence is less than 75%, less than 80%, less than 85%, less than 86%, less than 87%,less than 88%, less than 89%, less than 90%, less than 91%, less than 92%, less than 93%, less than 94%, less than 95%, less than 96%, less than 97%, less than 98%, less than 99%, or less than 100% identical to a sequence in Table 3.

[0100] The leptin may include the amino acid sequence of SEQ ID NO: 16 or 17. In some embodiments, the leptin includes an amino acid sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 16 or 17.

[0101] The leptin may include the amino acid sequence of SEQ ID NO: 16. In some embodiments, the leptin includes an amino acid sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 16.

[0102] The leptin may include the amino acid sequence of SEQ ID NO: 17. In some embodiments, the leptin includes an amino acid sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 17.Pharmaceutical compositions

[0103] A composition herein may include a pharmaceutical composition. A composition herein may be a pharmaceutical composition. Some embodiments relate to a pharmaceutical composition that includes a composition herein. In some embodiments, the pharmaceutical composition includes a lipid or lipids. In some embodiments, the pharmaceutical composition includes a FAST protein. In some embodiments, the pharmaceutical composition includes a nucleic acid encoding leptin. In some embodiments, the pharmaceutical composition includes lipids, a FAST protein, and a nucleic acid encoding leptin.

[0104] The composition may include a carrier. The pharmaceutical composition may include a carrier. The pharmaceutical composition may include a pharmaceutically acceptable carrier. The carrier may include water. The composition or pharmaceutical composition may include a solution. The carrier may include a solvent. The composition or pharmaceutical composition may include a salt, or may include salts. The carrier may include a buffer. The buffer may include phosphate buffered saline.

[0105] The pharmaceutical composition may include a pharmaceutically acceptable excipient. An example of an excipient includes sucrose. The excipient may be about 1 -10% ofthe overall pharmaceutical composition. The excipient may be 1 -10% of the overall pharmaceutical composition. The excipient may be about 5% of the overall pharmaceutical composition.Kits

[0106] A composition herein may be included in a kit. Some embodiments relate to a kit that includes the composition. In some embodiments, the kit includes a lipid or lipids. In some embodiments, the kit includes a FAST protein. In some embodiments, the kit includes a nucleic acid encoding leptin. In some embodiments, the kit includes lipids, a FAST protein, and a nucleic acid encoding leptin. In some embodiments, the kit includes instructions for use in a method, such as instructions for use in a method herein. Some embodiments include reagents for producing any aspect or combination of aspects used or included in a composition or method herein.II. Methods

[0107] Disclosed herein, in some embodiments, are methods that include using a composition herein. The method may include using a proteo-lipid vehicles (PLV), for example delivery of a PLV or administration of a composition that includes a PLV. The PLV may include lipids, a fusion-associated small transmembrane (FAST) polypeptide, and a nucleic acid encoding leptin. Some embodiments include delivering a composition herein to a cell or subject. Some embodiments include administering a composition herein to a subject. The composition may include a pharmaceutical composition. The administration may treat the subject. The administration may treat a disease.

[0108] Provided herein, in some embodiments, is a method of delivering a nucleic acid encoding leptin or a functional fragment thereof to a cell, comprising: contacting the cell with a proteo-lipid vehicle comprising a FAST polypeptide and said nucleic acid. In one aspect, provided herein is a method. The method may be used to deliver a nucleic acid encoding leptin of a functional fragment thereof to a cell. The method may comprise contacting the cell with a PLV. The PLV may comprise a recombinant FAST polypeptide. The PLV may comprise the nucleic acid. Some methods include use or administration of a PLV shown in Fig. 1 , or a composition that includes such a PLV.

[0109] In another aspect, provided herein is a method of increasing expression of leptin in a cell, comprising: contacting the cell with a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin. In one aspect, provided herein is a method. The method may be used to increase expression of leptin in a cell. The method may comprise contacting the cell with aproteo-lipid vehicle (PLV). The PLV may comprise a recombinant fusion-associated small transmembrane (FAST) polypeptide. The PLV may comprise a nucleic acid encoding leptin or a functional fragment thereof.[001 10] Increasing expression of leptin as used herein may include a result where levels of leptin after contacting the cell with a PLV comprising a FAST polypeptide and a nucleic acid encoding leptin are higher as compared to the levels of leptin in a baseline or control. The control can be any suitable control, as may be determined by those skilled in the art. For example, the control can be a cell not being contacted with any PLV, or a cell contacted with a control PLV. A control PLV can for example, be a PLV comprising a FAST polypeptide without the nucleic acid encoding leptin, or a PLV comprising a FAST polypeptide and a control nucleic acid. The control nucleic acid can for example, be a nucleic acid encoding luciferase. [001 1 1 ] The leptin or functional fragment thereof expressed from the nucleic acid delivered to the cell can be secreted by the cell.[001 12] In another aspect, provided herein is a method of treating a metabolic disease, or inducing or maintaining weight loss in a subject in need thereof, comprising: administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject. In one aspect, provided herein is a method. The method may be used to treat a metabolic disease, or induce or maintain weight loss in a subject in need thereof. The method may comprise administering a proteo-lipid vehicle (PLV) to the subject. The PLV may comprise a recombinant fusion-associated small transmembrane (FAST) polypeptide. The PLV may comprise a nucleic acid encoding leptin or a functional fragment thereof.[001 13] In another aspect, provided herein is a method of treating leptin deficiency in a subject in need thereof, comprising: administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject. In one aspect, provided herein is a method. The method may be used to treat leptin deficiency in a subject in need thereof. The method may comprise administering a proteo-lipid vehicle (PLV) to the subject. The PLV may comprise a recombinant fusion-associated small transmembrane (FAST) polypeptide. The PLV may comprise a nucleic acid encoding leptin or a functional fragment thereof.[001 14] In another aspect, provided herein is a method of increasing blood leptin levels in a subject in need thereof, comprising: administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject. In one aspect, provided herein is a method. The method may be used to increase blood leptin levels in a subject in need thereof. The method may comprise administering a proteo-lipid vehicle (PLV) to the subject.The PLV may comprise a recombinant fusion-associated small transmembrane (FAST) polypeptide. The PLV may comprise a nucleic acid encoding leptin or a functional fragment thereof.[001 15] In yet another aspect, provided herein is a method of treating lipodystrophy in a subject in need thereof, comprising: administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject. In one aspect, provided herein is a method. The method may be used to treat lipodystrophy in a subject in need thereof. The method may comprise administering a proteo-lipid vehicle (PLV) to the subject. The PLV may comprise a recombinant fusion-associated small transmembrane (FAST) polypeptide. The PLV may comprise a nucleic acid encoding leptin or a functional fragment thereof.[001 16] Contacting a cell with a PLV of the present disclosure may be accomplished by a variety of methods that bring together the cell and the PLV. Contacting a cell with a PLV of the present disclosure encompasses exposure of the cell to the PLV in vitro and / or in vivo. In vivo exposure can comprise, for example, administering the PLV to a subject and contacting occurs by a physiological process, such as through blood circulation. Contacting encompasses where the molecule or compound is produced in the body. Exposing the cell to the PLV in vitro can for example comprise incubating the cell with the PLV in a cell culture environment.[001 17] “Increasing expression of leptin” as used herein, means the levels of leptin after contacting the cell with a PLV comprising a FAST polypeptide and a nucleic acid encoding leptin are higher as compared to the levels of leptin in a control. The control can be any suitable control, as may be determined by those skilled in the art. For example, the control can be a cell not being contacted with any PLV, or a cell contacted with a control PLV. A control PLV can for example, be a PLV comprising a FAST polypeptide without the nucleic acid encoding leptin, or a PLV comprising a FAST polypeptide and a control nucleic acid. The control nucleic acid can for example, be a nucleic acid encoding luciferase.Subjects[001 18] Some embodiments include administering a composition herein to a subject. In some embodiments, the subject is a vertebrate. In some embodiments, the subject is an animal. In some embodiments, the subject is a mammal. In some embodiments, the subject is a primate. In some embodiments, the subject is human. In some embodiments, the subject is male. In some embodiments, the subject is female. In some embodiments, the subject is an adult (e.g. at least 18 years old).[001 19] The subject may be in need of treatment. The subject may be in need of treatment with a composition herein. The subject may be identified as in need of treatment.

[0120] In some embodiments, the subject has a disease. The subject may be identified as having a disease. The subject may be identified as likely to have a disease, or at risk of having a disease.

[0121] In some embodiments, the disease is a metabolic disease. The metabolic disease may include obesity. The metabolic disease may include lipodystrophy. The metabolic disease may include leptin deficiency. The leptin deficiency may be caused by a genetic disorder, such as a mutation in a leptin gene or in a gene affecting leptin production.

[0122] In some embodiments, the subject is overweight. An overweight subject may have a body mass index (BMI) above 25, above 26, above 27, above 28, or above 29. In some embodiments, the subject is obese. An obese subject may have a BMI above 30, above 31 , above 32, above 33, above 34, above 35, above 36, above 37, above 38, above 39, or above 40. In some embodiments, the subject has high blood glucose levels. In some embodiments, the subject is diabetic.Delivery

[0123] Some embodiments include delivering a composition herein to a subject. Delivery to a subject may include administering to a subject. Some embodiments include administering a composition herein to a subject. Some embodiments include delivering a composition herein to a cell. Delivery of a composition to a cell may include contacting the cell with the composition, or may include administering the composition to the cell. Some embodiments include contacting a cell with a composition herein. The cell may be a cell of a subject. The cell may be a fat cell or an adipocyte.

[0124] Contacting a cell with a PLV of the present disclosure may be accomplished by a variety of methods that bring together the cell and the PLV. Contacting a cell with a PLV of the present disclosure encompasses exposure of the cell to the PLV in vitro and / or in vivo. In vivo exposure can comprise, for example, administering the PLV to a subject and contacting occurs by a physiological process, such as through blood circulation. Contacting encompasses where the molecule or compound is produced in the body. Exposing the cell to the PLV in vitro can for example comprise incubating the cell with the PLV in a cell culture environment.

[0125] Delivery of a nucleic acid encoding leptin or a functional fragment thereof can result in expression of leptin or the functional fragment thereof in the cell. In cells where there is an endogenous expression of leptin, delivery of PLV comprising a nucleic acid encoding leptin can result in an increased expression of leptin in those cells.

[0126] The PLV can be used to deliver a nucleic acid encoding leptin or a functional fragment thereof in any cell. In some embodiments, the cell is an adipocyte. In some embodiments, the cell is a white adipocyte.

[0127] The delivery can be in vivo, ex vivo, or in vitro delivery.

[0128] Any suitable routes of administration can be used, such as intravenous injection. In some embodiments, administration includes intravenous administration. In some embodiments, administration includes an injection. In some embodiments, delivering the nucleic acid encoding the leptin or functional fragment thereof comprises intravenous delivery. In some embodiments, delivering the nucleic acid encoding the leptin or functional fragment thereof comprises an injection.

[0129] In some embodiments, administration includes intrathecal administration. In some embodiments, administration includes an intrathecal injection.

[0130] The administration may include a dose of a proteolipid vehicle. The dose may include about 1 -10 mg / kg. The dose may be about 1 -10 mg / kg. The dose may be 1 -10 mg / kg. The dose may be about 1 mg / kg, about 2 mg / kg, about 3 mg / kg, about 4 mg / kg, about 5 mg / kg, about 6 mg / kg, about 7 mg / kg, about 8 mg / kg, about 9 mg / kg, or about 10 mg / kg, or a range defined by any 2 of the aforesaid doses.

[0131] Administering a proteo-lipid vehicle comprising a recombinant fusion- associated small transmembrane (FAST) polypeptide and a nucleic acid to a subject can result in delivery of the nucleic acid to a cell of the subject. The nucleic acid can encode leptin or a functional fragment thereof.Effects

[0132] In some embodiments, treatment or administration of a composition herein to a subject results in an effect. Some such effects may include an increase in circulating leptin, fat loss, weight loss, decreased weight gain, decreased adiposity, or decreased appetite.

[0133] Some embodiments include an effect such as an improved effect. The effect may be improved or changed relative to a baseline. For example, some embodiments include a reduction in body weight relative to a baseline weight before treatment. An effect may be measured or identified. An effect may be determined or measured using a sample. An effect may be determined or measured in a sample of the subject, such as a biofluid sample or tissue sample. A measurement may be made directly in or on a subject, or through observation of a subject. A measurement may be obtained after a baseline measurement. A measurement may be obtained after treatment.

[0134] Administration of a composition may improve a parameter or aspect related to a disease. Administration of a composition may improve a body weight parameter. Theparameter may be improved (e.g. increased or decreased, depending on the parameter) by at least 1%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%. In some embodiments, the parameter is improved by no more than 1%, no more than 5%, no more than 10%, no more than 15%, no more than 20%, no more than 25%, no more than 30%, no more than 35%, no more than 40%, no more than 45%, no more than 50%, no more than 55%, no more than 60%, no more than 65%, no more than 70%, no more than 75%, no more than 80%, no more than 85%, no more than 90%, no more than 95%, or less than 100%.

[0135] Administration of a composition herein may treat a metabolic disease. In some embodiments, a metabolic disease relates to leptin deficiency. Examples of metabolic diseases that relate to leptin deficiency include but are not limited to lipodystrophy and obesity. In some embodiments, the metabolic disease is lipodystrophy. The lipodystrophy may include congenital lipodystrophy. In some embodiments, the metabolic disease is obesity.

[0136] Administering the proteo-lipid vehicle comprising the nucleic acid to a subject can restore glucose homeostasis in the subject.

[0137] In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in improved insulin sensitivity in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in improved insulin sensitivity in the subject relative to a baseline measurement or control.

[0138] In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower fasting insulin levels in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower fasting insulin levels in the subject relative to a baseline measurement or control.

[0139] In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower HbA1 c levels in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower HbA1c levels in the subject relative to a baseline measurement or control.

[0140] In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower hepatic triglyceride levels in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower hepatic triglyceride levels in the subject relative to a baseline measurement or control.

[0141] In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower blood triglyceride levels in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in lower blood triglyceride levels in the subject relative to a baseline measurement or control. The blood triglyceride levels may include serum triglyceride levels. The blood triglyceride levels may include plasma triglyceride levels. The blood triglyceride levels may include whole blood triglyceride levels.

[0142] In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in reduced food consumption in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in reduced food consumption in the subject relative to a baseline measurement or control. The reduction in food consumption can be, for example, a 1-30% reduction. In some embodiments, the food consumption is reduced by at least 1%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%. In some embodiments, the food consumption is reduced by no more than 1%, no more than 5%, no more than 10%, no more than 15%, no more than 20%, no more than 25%, no more than 30%, no more than 35%, or no more than 40%. The food consumption reduction may be over time. The food consumption reduction may be over a time period.

[0143] In some embodiments, the treatment or administration results in reduced weight gain. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in reduced weight gain in the subject compared to a control subject. In some embodiments, administrating the proteo-lipid vehicle comprising the nucleic acid results in reduced weight gain in the subject relative to a baseline measurement or control. The reduction in weight gain can be, for example, a 1 -25% reduction. In some embodiments, the treatment or administration results in at least 1%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, or at least 80% reduced weight gain s. In some embodiments, the treatment or administration results in no more than 1%, no more than 5%, no more than 10%, no more than 15%, no more than 20%, no more than 25%, no more than 30%, no more than 35%, no more than 40%, no more than 45%, no more than 50%, no more than 55%, no more than 60%, no more than 65%, no more than 70%, no more than 75%, or no more than 80% reduced weight gain. The reduction in weight gain may be over time. The reduction in weight gain may be over a time period.

[0144] In some embodiments, administrating the proteo-lipid vehicle results in weight loss. In some embodiments, the treatment or administration results in weight loss. In some embodiments, administrating the proteo-lipid vehicle results in at least 1% weight loss in thesubject. In some embodiments, the treatment or administration results in at least 1%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, or at least 80% weight loss. In some embodiments, the treatment or administration results in no more than 1 %, no more than 5%, no more than 10%, no more than 15%, no more than 20%, no more than 25%, no more than 30%, no more than 35%, no more than 40%, no more than 45%, no more than 50%, no more than 55%, no more than 60%, no more than 65%, no more than 70%, no more than 75%, or no more than 80% weight loss. The weight loss may be over time. The weight loss may be over a time period.

[0145] The weight loss or reduction in weight gain may be over a time period. The weight loss or reduction in weight gain may last for a time period. The time period may be about 1 day, about 5 days, about 10 days, about 15 days, about 20 days, about 25 days, about 30 days, about 35 days, about 40 days, about 45 days, about 50 days, about 55 days, about 60 days, about 65 days, about 70 days, about 75 days, about 80 days, about 85 days, about 90 days, about 95 days, about 100 days, about 105 days, about 110 days, about 115 days, about 120 days, about 125 days, about 130 days, about 135 days, about 140 days, about 145 days, or about 150 days, or a range of time defined by any 2 of the aforementioned numbers of days. The time period may be at least 1 day, at least 5 days, at least 10 days, at least 15 days, at least 20 days, at least 25 days, at least 30 days, at least 35 days, at least 40 days, at least 45 days, at least 50 days, at least 55 days, at least 60 days, at least 65 days, at least 70 days, at least 75 days, at least 80 days, at least 85 days, at least 90 days, at least 95 days, at least 100 days, at least 105 days, at least 110 days, at least 115 days, at least 120 days, at least 125 days, at least 130 days, at least 135 days, at least 140 days, at least 145 days, or at least 150 days. The time period may be less than days, less than 5 days, less than 10 days, less than 15 days, less than 20 days, less than 25 days, less than 30 days, less than 35 days, less than 40 days, less than 45 days, less than 50 days, less than 55 days, less than 60 days, less than 65 days, less than 70 days, less than 75 days, less than 80 days, less than 85 days, less than 90 days, less than 95 days, less than 100 days, less than 105 days, less than 110 days, less than 115 days, less than 120 days, less than 125 days, less than 130 days, less than 135 days, less than 140 days, less than 145 days, or less than 150 days.

[0146] An effect (e.g. a treatment effect, or affect of administration of a composition herein) may be measured. An effect may be measured in a sample. A sample may include a biofluid sample. A biofluid sample may include blood, serum, or plasma. An effect may be measured in a blood sample. A blood sample may be or include whole blood. An effect may be measured in a serum sample. An effect may be measured in a plasma sample.

[0147] An effect may be measured in a tissue sample. An example of a tissue sample includes a liver sample. An example of a tissue sample includes a fat sample. Fat may include white fat. A sample may be obtained via biopsy. A measurement may be made through observation, histology, an immunoassay, an enzymatic assay, or the like. A measurement may be obtained through microscopy. A measurement may be obtained visually.

[0148] Some embodiments include an effect that is different relative to a baseline such as a baseline measurement. For example, some embodiments include a reduction in body weight relative to a baseline measurement. A baseline measurement may be made in a sample. The baseline measurement may be made in a sample of the subject, such as a biofluid sample or tissue sample. A baseline measurement may be made directly in or on a subject, or through observation of a subject. A baseline measurement may be made prior to a treatment. A baseline measurement may be made prior to a later measurement.

[0149] Some embodiments include an effect that is different relative to a control. A control may include a control subject. A control subject can be any suitable control subject. For example, the control subject can be a subject administered a PLV comprising a control nucleic acid. A control may include a standard. An example of a standard may be a level of amount that is considered deleterious. Some embodiments include an improvement of a metabolic parameter relative to a standard, or an improvement past or below what the standard represents.III. Definitions

[0150] Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by those of ordinary skill in the art to which the disclosure pertains.

[0151] As used herein, the singular forms “a”, “an” and “the” include the plural forms unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise. These terms can convey that any combination is specifically contemplated. Solely for illustrative purposes, the expression “A, B, and / or C” can mean A individually; B individually; C individually; A and B; B and C; A and C; and A, B, and C.

[0152] In understanding the scope of the present disclosure, the term "comprising" and its derivatives, and words having similar meanings such as "including", "having", “containing” and their derivatives, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and / or steps, and do not exclude the presence of additional or unrecited features, elements, components, groups, integers and / or steps.

[0153] The term “consisting” and its derivatives, as used herein, are intended to be closed ended terms that specify the presence of stated features, elements, components, groups, integers, and / or steps, and also exclude the presence of other unrecited features, elements, components, groups, integers and / or steps.

[0154] Further, terms of degree such as "substantially", "about" and "approximately" as used herein mean within an acceptable error range for the particular value, or a reasonable amount of deviation of the modified term, as determined by one of ordinary skill in the art. These terms of degree should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.

[0155] More specifically, the term “about” means plus or minus 0.1 to 20%, 5-20%, or 10-20%, 10%-15%, preferably 5-10%, most preferably about 5% of the number to which reference is being made. The recitation of numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range (e.g. 1 to 5 includes 1 , 1 .5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term "about."

[0156] The terms “determining,” “measuring,” “evaluating,” “assessing,” “assaying,” and “analyzing” may be used interchangeably herein to refer to forms of measurement. The terms include determining if an element is present or not (for example, detection). These terms can include quantitative, qualitative or quantitative and qualitative determinations. Assessing can be relative or absolute. “Detecting the presence of” can include determining the amount of something present in addition to determining whether it is present or absent depending on the context.

[0157] A “nucleic acid” may include single stranded or double stranded polymers of nucleotide monomers, including DNA, RNA, or DNA / RNA hybrid molecules, or may encompass modifications or analogues.

[0158] The terms “polypeptide” and “protein” are used interchangeably and refer to a polymer of at least two amino acids. The amino acids may be natural amino acids, or analogues or derivatives thereof. The term encompasses modifications.

[0159] The term “functional fragment” in the context of a protein or polypeptide means a fragment that is capable of having one or more activities of a reference protein or polypeptide. For example, a functional fragment of leptin can refer to a fragment of leptin that is capable of activating a leptin receptor to the same extent or at least a substantially same extent as leptin.

[0160] A sequence herein may encode or include a conservative amino acid substitution. As used herein, the term “conservative amino acid substitution” refers to a substitution of an amino acid residue with another amino acid residue without abolishing theprotein's desired properties. The substitution can be with an amino acid of the same class. These classes include, for example, amino acids having uncharged polar side chains, such as asparagine, glutamine, serine, threonine, and tyrosine; amino acids having basic side chains, such as lysine, arginine, and histidine; amino acids having acidic side chains, such as aspartic acid and glutamic acid; and amino acids having nonpolar side chains, such as glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan and cysteine. A conservative amino acid substitution also include substitution with a chemically derivatized residue or non-natural amino acid so long as the substitution does not abolish the protein's desired properties.

[0161] The term "sequence identity" as used herein refers to the percentage of sequence identity between two amino acid sequences or two nucleic acid sequences. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences. The sequences can be of the same length or of different lengths. Gaps may be artificially introduced into the sequence to attain proper alignment. Once the optimal alignment has been set up, the degree of identity is established by recording all of the positions in which the amino acids of both sequences are identical, relative to the total number of positions. As would be understood by a person skilled in the art, the determination of percent identity between two sequences can also be accomplished using a mathematical algorithm. Various sequence analysis software and online programs can be used to determine sequence identity, such as BLAST.

[0162] In determining a sequence identity, thymine (T) and uracil (U) may be interchangeable. T and U may be interchangeable when describing an oligonucleotide. In some embodiments, T s and Us are interchangeable depending on whether the oligonucleotide is an RNA or DNA, where RNA includes U and DNA includes T. Where a T is provided as a part of DNA, a U may be envisaged as part of an RNA, and vice versa.

[0163] Any discrepancies between the written description and a sequence listing submitted herewith may typically be resolved in favor of the written description.

[0164] The term “treat”, “treating” or similar terms may include achieving a beneficial or desired result, which can comprise (1) diminishing the extent of or reversing a disease or condition; (2) slowing, delaying, or arresting the progression of a disease or condition; (3) ameliorating or alleviating one or more symptoms of a disease or condition.

[0165] The term “prevent”, “preventing” or the like, in the context of a disease or condition, may include avoiding the development of a disease or condition and / or the onset of one or more symptoms.

[0166] The term “effective amount” may include an amount that is sufficient to elicit a desired effect or response, such as to reduce weight gain or to maintain weight loss.

[0167] The term “pharmaceutically effective amount” may include an amount sufficient to treat or prevent a disease or condition. Such an amount can depend on factors such as a subject’s size and state of health, the extent of the disease or condition being treated.

[0168] As used herein, the term “administering”, “administer”, or the like may include introducing the PLV of the present disclosure and / or a molecule, as the case may be, to a subject by a variety of methods. The term can encompass external and internal administration. Internal administration can refer to, for example, where a molecule is generated inside the subject’s body. For example, administering a polypeptide may encompass administering a nucleic acid encoding the polypeptide, and the polypeptide is expressed from the nucleic acid inside a cell of the subject. The term can encompass sequential administration, e.g. introducing the compound at a regular interval.

[0169] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0170] The definitions and embodiments described in particular sections are intended to be applicable to other embodiments herein described for which they are suitable as would be understood by a person skilled in the art.

[0171] Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, examples of methods and materials are now described.

[0172] Various features and embodiments of the present invention will now be described by way of non-limiting examples.EXAMPLES

[0173] It is demonstrated herein that a single injection of a proteo-lipid vehicle (PLV) comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin into leptin deficient subjects can result in durable expression of leptin, and reduction in weight gain or even weight loss, relative to similar subjects not treated with the PLV encoding leptin. It is here demonstrated herein that injection of a PLV comprising leptin-encoding DNA to obese mice results in durable expression of leptin, reduced food consumption, reduced weight gain, and restored glucose homeostasis in the mice.Example 1. Intravenous delivery of a plasmid DNA encoding human leptin using PLV technology

[0174] A PLV comprising a nucleic acid encoding leptin (PLV-Leptin) was tested to determine metabolic effects in mammals. The PLV included the FAST protein of SEQ ID NO: 1 , lipids, and a DNA plasmid that included the sequence of SEQ ID NO: 12, encoding a human leptin protein having the amino acid sequence of SEQ ID NO: 16. The PLV was administeredat a dose of 4 mg / kg via a single intravenous (IV) injection via tail vein. The PLV-Leptin in this study was formulated with PBS and 5% sucrose. The amount of FAST proteins relative to lipids was about 1-2% in this study and in Examples 2-4.

[0175] PLV-Leptin was injected into leptin deficient (ob / ob) mice (n=10) via a single intravenous injection at Day 0. The leptin deficiency resulted from a leptin knockout, and is a model of lipodystrophy and obesity. As a control, a similar PLV with DNA encoding luciferase instead of leptin (PLV-Control) was used. PLV-Control was also injected into ob / ob mice (n=10) via a single intravenous injection at Day 0. Mice in this study were about 34 days old at injection. All mice in this example, and Examples 2-4 were female.

[0176] Leptin levels were measured in PLV-Leptin ob / ob mice and PLV-Control ob / ob mice up to Day 58. Fig. 2 shows that durable expression of leptin was achieved in PLV-Leptin ob / ob mice. 30% less weight gain in PLV-Leptin ob / ob mice was observed at Day 58 as compared to PLV-Control ob / ob mice (Fig. 3). By Day 58, PLV-Leptin ob / ob mice consumed about 35% less food than PLV-Control ob / ob mice (Fig. 4). Furthermore, change in blood glucose in PLV-Leptin ob / ob mice was not significantly different from uninjected C57BL / 6 mice, while in PLV-Control ob / ob mice, glucose homeostasis was impaired (Fig. 5). Thus, PLV-leptin restored metabolic homeostasis. Fig. 6 shows that the morphology of ob / ob mice was reversed after injection of PLV-Leptin.

[0177] As demonstrated, the PLV-leptin can be used to deliver leptin to a cell. Unexpectedly, a single dose of PLV-leptin resulted in 30% less weight gain after about 30 days, and complete glucose control. The PLV-leptin can be useful in treating metabolic diseases.Example 2. Durable disease modifying effects with PLV leptin delivery

[0178] A study similar to Example 1 was performed, but treatment effects were observed for a longer time period. A single 120 pg dose of a proteolipid vehicle that included the FAST protein of SEQ ID NO: 1 , lipids, and a DNA plasmid that included the sequence of SEQ ID NO: 12 (PLV-Leptin) was delivered intravenously via tail vein to ob / ob mice, and compared to a single dose of a control (n=10 / group). The PLV-Leptin in this study was formulated with PBS and 5% sucrose. The study period in this example was for about 180 days. Mice in this study were about 31 days old at injection.

[0179] Results indicated that human leptin expression reverses the ob / ob phenotype for 172 days with single dose. Fig. 7 shows a durable a durable 30% reduction in weight gain by 172 days after treatment was administered in the PLV-Leptin group. Fig. 8 shows restoration of therapeutic leptin levels in Ob / Ob mice for 172 days, all from a single PLV dose.

[0180] Additional data showed complete normalization of liver homeostasis with PLV- Leptin. Fig. 9A shows liver oil red staining where untreated wild-type C57 mice and PLV- Leptin-treated ob / ob mice show little or no oil red staining, where on the other hand, the ob / ob PLV-Control-treated mice show abundant oil red staining. Oil red droplet quantification is shown in Fig. 9B. Fig. 10 shows a reduction in liver weight by PLV-leptin, and Fig. 11 shows a reduction in liver triglycerides. The data indicate that PLV-leptin treatment was surprisingly effective and long-lasting.Example 3. PLV-Leptin prevents weight gain and diabetes

[0181] A study similar to Example 2 was performed, using a PLV-Leptin composition delivered intrathecally (IT). A single 25 pg or 12.5 pg dose of a proteolipid vehicle that included the FAST protein of SEQ ID NO: 1 , lipids, and a DNA plasmid that included the sequence of SEQ ID NO: 12 (PLV-Leptin) was delivered IT to ob / ob mice, and compared to a single dose of a control (n=8 / group). The dose in this experiment was about 1 / 5 or less compared to the amount of the IV dose in Example 2. The PLV-Leptin in this study was formulated in PBS without sucrose. The study period was for over 100 days. Mice in this study were about 31 days old at injection.

[0182] This study Leveraged the primary signaling pathway of leptin in the brain and hypothalamus, since leptin can exert effects by binding to leptin receptors (LepRs) located primarily in the brain and hypothalamus. Results indicated that a single IT dose of PLV-Leptin was sufficient to prevent onset of the ob / ob metabolic phenotype. As seen in Fig. 12, the PLV- Leptin composition resulted in sustained weight loss in ob / ob mice. It was surprising that the mice lost weight and maintained the weight loss, beyond mere weight gain prevention. As shown in Fig. 13, the PLV-Leptin composition resulted in complete diabetes control within 7 days of the PLV-Leptin composition administration. Fig. 14 shows mice toward the end of the study, and Fig. 15 shows human leptin measurements in the mice.

[0183] Despite similar circulating leptin levels at 1 / 5 the IV dose, substantially improved potency was observed in this study, and the ob / ob mice lost weight and maintained their weight loss over 90 days. While animals were diabetic (here, over 200 mg / dL blood glucose levels) at the study’s start, every animal that received the PLV-Leptin composition had normal glucose blood levels after only 7 days, and this was maintained over 90 days.Example 4. PLV-Leptin reverses weight gain in older ob / ob mice

[0184] A study similar to Example 3 was performed, using older mice that were already obese at the study’s start. A single 25 pg dose of PLV-Leptin composition that included the FAST protein of SEQ ID NO: 1 , lipids, and a DNA plasmid that included the sequence of SEQID NO: 12 (PLV-Leptin) was delivered IT to obese, aged ob / ob mice, and compared to a single dose of a control (n=7 / group). The PLV-Leptin in this study was formulated in PBS without sucrose. Mice in this study were about 85 days old at injection.

[0185] Results indicated that a single dose of the PLV-Leptin was sufficient to reverse ob / ob phenotypes. As shown in Fig. 16, the PLV-Leptin composition resulted in sustained weight loss in ob / ob mice. As seen in Fig. 17, the PLV-Leptin composition resulted in complete diabetes control within 7 days. Fig. 18 shows mice toward the end of the study.

[0186] These results surprisingly demonstrated treatment activity at advanced disease stages. Despite similar circulating leptin levels at 1 / 5 dose compared to IV treatment, substantially improved potency was observed in this study, and the obese Ob / Ob mice returned to normal weight in 21 days and maintained normal weight for over 75 days. Surprisingly, every animal that received the PLV-Leptin composition had normal glucose after only 7 days. The sustained weight loss of over 70% and complete glucose control indicate that the treatment was surprisingly effective.

[0187] While the present application has been described with reference to what are presently considered to be the preferred examples, it is to be understood that the application is not limited to the disclosed examples. To the contrary, the application is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0188] All publications, patents and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety. Specifically, the sequences associated with each accession numbers provided herein including for example accession numbers and / or biomarker sequences (e.g. protein and / or nucleic acid) provided in the Tables or elsewhere, are incorporated by reference in its entirely.

[0189] The scope of the claims should not be limited by the embodiments and examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

CLAIMS1 . A composition comprising a proteo-lipid vehicle comprising a recombinant fusion- associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof.

2. The composition of claim 1 , wherein the FAST polypeptide comprises a p10 FAST protein, a p13 FAST protein, a p14 FAST protein, a p15 FAST protein, a p16 FAST protein, or a p22 FAST protein, or a fragment thereof.

3. The composition of claim 1 , wherein the FAST polypeptide comprises a fusion protein comprising a p14 ectodomain and a p15 endodomain.

4. The composition of claim 1 , wherein the FAST polypeptide comprises a p14 transmembrane domain or a p15 transmembrane domain, or a fragment thereof.

5. The composition of claim 1 , wherein the nucleic acid comprises DNA.

6. The composition of claim 1 , wherein the nucleic acid comprises a DNA plasmid.

7. The composition of claim 1 , wherein the nucleic acid comprises mRNA.

8. The composition of claim 1 , wherein the leptin includes an amino acid sequence at least 70%, at least 75%, at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to SEQ ID NO: 16 or 17.

9. A method, comprising administering the composition of any one of claims 1-8 to a subject.

10. A method of delivering a nucleic acid encoding leptin or a functional fragment thereof to a cell, comprising contacting the cell with a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and said nucleic acid.

11. A method of increasing expression of leptin in a cell, comprising contacting the cell with a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin.

12. A method of treating a metabolic disease, or inducing or maintaining weight loss in a subject in need thereof, comprising administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject.

13. The method of claim 12, wherein the metabolic disease comprises leptin deficiency.

14. The method of claim 12, wherein the metabolic disease comprises lipodystrophy or obesity.

15. A method of treating leptin deficiency in a subject in need thereof, comprising administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject.

16. A method of increasing blood leptin levels in a subject in need thereof, comprising administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin to the subject.

17. A method of treating lipodystrophy in a subject in need thereof, comprising administering a proteo-lipid vehicle comprising a recombinant fusion-associated small transmembrane (FAST) polypeptide and a nucleic acid encoding leptin or a functional fragment thereof to the subject.

18. The method of any one of claims 10-17, wherein the FAST polypeptide comprises a p10 FAST protein, a p13 FAST protein, a p14 FAST protein, a p15 FAST protein, a p16 FAST protein, or a p22 FAST protein, or a fragment thereof.

19. The method of any one of claims 10-17, wherein the FAST polypeptide comprises a fusion protein comprising a p14 ectodomain and a p15 endodomain.

20. The method of any one of claims 10-17, wherein the FAST polypeptide comprises a p14 transmembrane domain or a p15 transmembrane domain, or a fragment thereof.21 . The method of any one of claims 10-17, wherein the nucleic acid comprises DNA.

22. The method of any one of claims 10-17, wherein the nucleic acid comprises a DNA plasmid.

23. The method of any one of claims 10-17, wherein the nucleic acid comprises a mRNA.

24. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in delivery of the nucleic acid to a cell of the subject.

25. The method of claim 24, wherein delivery of the nucleic acid to the cell results in an increase in leptin expression in the cell.

26. The method of claim 25, wherein the expressed leptin or functional fragment thereof is secreted by the cell.

27. The method of claim 25, wherein the cell is an adipocyte.

28. The method of claim 25, wherein the cell is a white adipocyte.

29. The method of any one of claims 12-17, wherein administering the nucleic acid comprises intravenous delivery or an injection.

30. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in improved insulin sensitivity in the subject relative to a baseline measurement or control.

31. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in lower fasting insulin levels in the subject relative to a baseline measurement or control.

32. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in lower HbA1c levels in the subject relative to a baseline measurement or control.

33. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in lower hepatic triglyceride levels in the subject relative to a baseline measurement or control.

34. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in lower blood triglyceride levels in the subject relative to a baseline measurement or control.

35. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in reduced food consumption in the subject relative to a baseline measurement or control.

36. The method of claim 35, wherein the reduction in food proteo-lipid vehicle comprises a 1 -30% reduction.

37. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in reduced weight gain in the subject relative to a baseline measurement or control.

38. The method of claim 37, wherein the reduction in weight gain comprises a 1 -25% reduction.

39. The method of any one of claims 12-17, wherein administering the proteo-lipid vehicle results in weight loss in the subject relative to a baseline measurement.

40. The method of claim 39, wherein the weight loss is 1 -30% weight loss.

41. The method of any one of claims 12-17, wherein administering the composition results in stabilized blood glucose levels in the subject relative to a baseline measurement or control.

42. The method of claim 12, wherein the metabolic disease comprises lipodystrophy.

43. The method of claim 12, wherein the metabolic disease comprises obesity.

44. The method of any one of claims 10-17, wherein the leptin is human leptin.

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