Background
Shh gene transfer improves myocardial recovery by up-regulating angiogenic genes and enhancing the incorporation of bone marrow-derived progenitor cells (BMPCs) in infarcted myocardium. Here, we investigated whether the effectiveness of Shh gene therapy could be improved with AMD3100-induced progenitor-cell mobilization.
Conclusions
Combination therapy consisting of intramyocardial Shh gene transfer and AMD3100-induced progenitor-cell mobilization improves cardiac functional recovery after MI and is superior to either individual treatment for promoting therapeutic neovascularization.
Methods
Gene expression and cell function were evaluated in cells cultured with medium collected from fibroblasts transfected with plasmids encoding human Shh (phShh). MI was induced in wild-type mice, in matrix metalloproteinase (MMP)-9 knockout mice, and in mice transplanted with bone marrow that expressed green-fluorescent protein. Mice were treated with 100 μg of phShh (administered intramyocardially), 5 mg/kg of AMD3100 (administered subcutaneously), or both; cardiac function was evaluated echocardiographically, and fibrosis, capillary density, and BMPC incorporation were evaluated immunohistochemically.
Results
phShh increased vascular endothelial growth factor and stromal cell-derived factor 1 expression in fibroblasts; the medium from phShh-transfected fibroblasts increased endothelial-cell migration and the migration, proliferation, and tube formation of BMPCs. Combination therapy enhanced cardiac functional recovery (i.e., left ventricular ejection fraction) in wild-type mice, but not in MMP-9 knockout mice, and was associated with less fibrosis, greater capillary density and smooth muscle-containing vessel density, and enhanced BMPC incorporation. Conclusions: Combination therapy consisting of intramyocardial Shh gene transfer and AMD3100-induced progenitor-cell mobilization improves cardiac functional recovery after MI and is superior to either individual treatment for promoting therapeutic neovascularization.