title: Nanoparticle based delivery of hypoxia-regulated VEGF transgene system combined with myoblast engraftment for myocardial repair.
abstract: A regulated promoter system to control gene expression is desirable for safe and efficacious over-expression of therapeutic transgene. Combined with skeletal myoblast (SkMs), we report the efficacy of hypoxia-regulated VEGF gene delivery for myocardial repair during acute myocardial infarction (AMI). A hypoxia-regulated VEGF plasmid (pHRE-VEGF) was developed. After optimization, ∼30% SkMs were transfected using polyethyleneimine (PEI) nanoparticles. The peak VEGF expression was higher in pHRE-VEGF transfected SkMs ((VEGF)SkMs) under hypoxia (151.34 ± 8.59 ng/ml) than that with normoxia (16.92 ± 2.74 ng/ml). The efficacy of hypoxia-regulated gene expression system was assessed in a rabbit model of AMI. The animals were grouped to receive basal M199 without cells (group-1) or containing non-transfected SkMs (group-2) or (VEGF)SkMs (group-3). In group-4, (VEGF)SkMs were injected into normal heart to serve as normoxia control. Improved SkM survival was observed in group-3 and -4 (p < 0.05 vs group-2) at day-3 and 7 after transplantation. Blood vessel density was 20.1 ± 1.3 in group-3 which was significantly higher than any other groups (p < 0.05) at 2 weeks after treatment. Improved blood flow (ml/min/g) in the left ventricle (LV) anterior wall was observed in group-3 (1.28 ± 0.09, p < 0.05) as compared with group-1 (0.76 ± 0.05) and group-2 (0.96 ± 0.06), and similar to group-4 (1.26 ± 0.05). LV ejection fraction was best preserved in group-3 (58.4 ± 1.75%) which was insignificantly different from group-4 (61.1 ± 1.8%), and group-2 (52.8 ± 1.4%), but significantly improved compared with group-1 (44.7 ± 2.2%, p < 0.05). The study demonstrates that nanoparticle based delivery of hypoxia-regulated VEGF transgene combined with SkMs during AMI effectively preserves LV regional blood flow and contractile function of the heart.
authors.affiliation: Cardiovascular Research Institute, National University Medical Institutes, National University of Singapore, Singapore 117597, Singapore.
authors.forename: Lei
authors.initials: L
authors.lastname: Ye
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Su
authors.forename: Husnain K
authors.initials: HK
authors.lastname: Haider
authors.forename: Kian-Keong
authors.initials: KK
authors.lastname: Poh
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Galupo
authors.forename: Geronica
authors.initials: G
authors.lastname: Songco
authors.forename: Ruo-Wen
authors.initials: RW
authors.lastname: Ge
authors.forename: Huay-Cheem
authors.initials: HC
authors.lastname: Tan
authors.forename: Eugene K W
authors.initials: EK
authors.lastname: Sim
mesh_terms: D000818:Animals; D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006334:Heart Function Tests; D006801:Humans; D032446:Myoblasts / Q000166:cytology / Q000187:drug effects / Q000637:transplantation*; D009206:Myocardium / Q000473:pathology*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D018919:Neovascularization, Physiologic / Q000187:drug effects; D011094:Polyethyleneimine / Q000494:pharmacology; D011817:Rabbits; D012039:Regional Blood Flow / Q000187:drug effects; D020218:Response Elements / Q000235:genetics; D014162:Transfection; D019076:Transgenes / Q000235:genetics*; D042442:Vascular Endothelial Growth Factors / Q000235:genetics*; D014945:Wound Healing / Q000187:drug effects
chemical_list: D042442:Vascular Endothelial Growth Factors; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D011094:Polyethyleneimine