Local delivery of cardiac stem cells overexpressing HIF-1α promotes angiogenesis and muscular tissue repair in a hind limb ischemia model

Critical limb ischemia (CLI) is the most advanced stage of peripheral artery disease, associated with significant risk of limb loss, morbidity and mortality; however, there remains unmet therapeutic needs for arterial revascularization and ischemic tissue repair. Stem cell therapies have emerged as compelling candidates due to beneficial proangiogenic and immunosuppressive function. Nevertheless, in vivo efficacy was insufficient in proliferation, differentiation and survival/engraftment rate. Cardiac stem cells (CSCs) was firstly attempted for CLI as a novel therapeutic modality to provide superior angiogenic potency to bone marrow-derived stem cells (BMSCs). It was noted that CSCs demonstrated 3.2-fold in HGF, 2.9-fold in VEGF and 8.7-fold in PDGF-B higher gene expressions compared to BMSCs. To enhance the hypoxia-induced proangiogenic effect, CSCs were transfected with hypoxia-inducible factor-1 alpha (HIF-1α) by using electroporation method, specifically optimized for CSCs yielding 45.77% of transfection efficiency and 89.75% of viability. HIF-1α overexpression significantly increased CSC survival in hypoxia, proangiogenic factors production and endothelial differentiation. In mouse hind limb ischemia model, local intramuscular delivery of CSC overexpressing HIF-1α (HIF-CSC) significantly improved the blood flow recovery. Histological analysis revealed that muscle degeneration and fibrosis in the ischemic limb were attenuated. Local delivery of HIF-CSC might be a promising option for ischemic tissue restoration.