Novel Gene-Modified Mesenchymal Stem Cell Therapy Reverses Impaired Wound Healing in Ischemic Limbs

Here, we report a new method to increase the therapeutic potential of mesenchymal stem/stromal cells (MSCs) for ischemic wound healing. We tested biological effects of MSCs modified with E-selectin, a cell adhesion molecule capable of inducing postnatal neovascularization, on a translational murine model. BACKGROUND: Tissue loss significantly worsens the risk of extremity amputation for patients with chronic limb-threatening ischemia. MSC-based therapeutics hold major promise for wound healing and therapeutic angiogenesis, but unmodified MSCs demonstrate only modest benefits. METHODS: Bone marrow cells harvested from FVB/ROSA26Sor(mTmG) donor mice were transduced with E-selectin-green fluorescent protein (GFP)/AAV-DJ or GFP/AAV-DJ (control). Ischemic wounds were created via a 4 mm punch biopsy in the ipsilateral limb after femoral artery ligation in recipient FVB mice and subsequently injected with phosphate-buffered saline or 1×10(6) donor MSC(GFP) or MSC(E-selectin-GFP). Wound closure was monitored daily for 7 postoperative days, and tissues were harvested for molecular and histologic analysis and immunofluorescence. Whole-body DiI perfusion and confocal microscopy were utilized to evaluate wound angiogenesis. RESULTS: Unmodified MSCs do not express E-selectin, and MSC(E-selectin-GFP) gain stronger MSC phenotype yet maintain trilineage differentiation and colony-forming capability. MSC(E-selectin-GFP) therapy accelerates wound healing compared with MSC(GFP) and phosphate-buffered saline treatment. Engrafted MSC(E-selectin-GFP) manifest stronger survival and viability in wounds at postoperative day 7. Ischemic wounds treated with MSC(E-selectin-GFP) exhibit more abundant collagen deposition and enhanced angiogenic response. CONCLUSIONS: We establish a novel method to potentiate regenerative and proangiogenic capability of MSCs by modification with E-selectin/adeno-associated virus. This innovative therapy carries the potential as a platform worthy of future clinical studies.