Cell based gene therapy using mesenchymal stem cells and vascular endothelial growth factor in ischemic heart disease rat model

Abstract

In primary cultured cells including bone marrow-derived MSCs, most transfection techniques achieve very low efficiencies, generally no more than a few percent. Thus, preparing effective transfection methodologies is crucial to the success of MSC-based gene therapy. Facial amphiphiles having hydrophilic and hydrophobic groups located on two opposite faces have known to destabilize plasma membrane and enhance their cellular permeability. To develop efficient transfection methodologies for MSCs, herein different types of bile acids having facial amphiphilicity were conjugated to low molecular weight polyethyleneimine (PEI1.8,1.8kDa) (BA-PEI1.8). The purpose of the present study is to enhance in vitro gene transfection efficiencies in rat MSCs with various bile acid-modified cationic gene carriers. Herein, hypoxia inducible VEGF plasmid modified MSCs was used as an effective cell-based gene therapy strategy for salvaging myocardial ischemia and infarction.First, we synthesized different types of bile acid-conjugated PEIs (DA-PEI, CA-PEI, LA-PEI) to use as gene carriers for primary cultured MSCs. Gene transfection efficiency and cell toxicity in mesenchymal stem cells (MSCs) was examined with different BA-PEI1.8 conjugates. Compared with conventional transfection reagents, DA-PEI1.8 exhibited more than 10-fold higher transfection efficiency in rat MSCs. In particular, DA-PEI1.8 conjugate could increase VEGF gene expression in MSCs up to 50-fold higher than commercialized transfection reagent (Lipofectamine). The transplantation of MSCs genetically modified to overexpress VEGF by BA-PEI1.8 enhanced the capillary formation in the infarction region and eventually attenuated left ventricular remodeling after myocardial infarction in rats. This study demonstrates the applicability of the BA-PEI1.8 conjugates for the efficient transfection of therapeutic genes into MSCs and the feasibility of using the genetically engineered MSCs in regenerative medicine for myocardial infarction.