Human Mesenchymal Stem Cells Modified by Hepatocyte Growth Factor Gene Promote Angiogenesis of Local Limb Ischemia in Rats

Objective To evaluate the angiogenesis-promoting activities of human mesenchymal stem cells(hMSCs) modified by hepatocyte growth factor(HGF) in vivo and further investigate the underlying mechanisms.Methods Wistar rat limb ischemia model was developed by ligation of the right femoral artery.hMSC were infected by an adenoviral vector carrying human HGF cDNA.Aliquots of hMSC/Ad-HGF,hMSC or PBS were injected intramuscularly into the ischemic area of a rat limb ischemia model and 21 days later,laser Doppler perfusion imaging was performed to detect the blood flow of the limbs.Microvessel density(MVD) was evaluated by HE staining and immunohistochemistry on skeletal muscle sections.Evaluation of proliferation,migration and forming tube-like structures on ECV304 cells impacted by hMSC/Ad-HGF was determined by MTT,Transwell migration and tubercular structure formation assays.Results In contrast to PBS,injection of hMSC/Ad-HGF and hMSC significantly improved the blood flow perfusion of the ischemic limbs.The relative means of the blood perfusion in hMSC/Ad-HGF-treated rats were comparable to those of the left legs and greater than those of hMSCtransplanted legs(P0.05).The amounts of micro-vessels per high-fold field were highest in the hMSC/Ad-HGF-treated muscles,followed by those of PBS and hMSC,and all of them were greatly higher than those of normal controls(P0.01).The supernatants of hMSC/Ad-HGF were shown to promote the proliferation of ECV304 cells and the stimulation activity was greater than that from recombinant human epithelial growth factor at a concentration of 20 ng/mL(P0.001).In agreement,the conditioned medium of hMSC/Ad-HGF exhibited a greater activity than epithelial growth factor to enhance the transmembrane migration and tubercular structure formation of ECV304 cells.Conclusion HGF gene-modified human mesenchymal stem cells promote the proliferation,migration and vascular formation of endothelial cells,thus activating the angiogenesis process.