VEGF gene modified allogenic bone marrow-derived mesenchymal stem cells therapy in diabetic hindlimb ischemia rats

Diabetes mellitus (DM), a worldwide difficult problem, is still lack of effective treatment so far. Bone marrow-derived mesenchymal stem cells (BMMSCs), with a low immunogenicity, is a promising source which can be used for revascularization and repair of hindlimb ischemia of DM. Vascular endothelial growth factor (VEGF), a strongest cytokine to promote the growth of blood vessel, could do function on revascularization or not is unknown yet. In this study, rat type 2 diabetes mellitus (T2DM) hindlimb ischemia model was established by intraperitoneal injection of streptozotocin (STZ) and thereafter ligating of the bilateral femoral arteries and their branches around. BrdU-labelled passage 3 BMMSCs were randomly divided into three groups including BMMSCs group, empty vector of green fluorescent protein labelled adenovirus (Ad-GFP) transfected BMMSCs (Ad-GFP-BMMSCs) group and VEGF gene-expressing Ad-GFP modified BMMSCs (Ad-VEGF-GFP-BMMSCs) group. Then those cells in each group were respectively injected into the left rectus femoris and gastrocnemius of the corresponding T2DM models. Digital subtraction angiography (DSA) of hindlimbs arteries were performed after transplantation and H&E staining and it showed there were more abundant blood vessels in the Ad-VEGF-GFP-BMMSCs group than the other two groups. The capillary density of bilateral rectus femoris and gastrocnemius in Ad-VEGF-BMMSCs group was superior significantly to that in the other two groups at the corresponding time point. Combining the result of immunofluorescence staining, we could confirm VEGF gene modified BMMSCs could survive in situ and contribute to neovascularization in T2DM hindlimb ischemia rats.