Abstract 5755: The Role of Adhesion and Migration of Stimulated Multipotent Stromal Cell With EGF in Vasculogenesis in Type 2 Diabetes
Background: Chronic tissue ischemia due to defective vascular perfusion is a marker of peripheral artery disease for which minimal therapeutic options exist. Thus, type 2 diabetes is characterized with altered stem cells and vasculogenesis. Because of the capability of stem cells to differentiate into vascular cells and the importance of epidermal growth factor (EGF) in angiogenesis, their critical role in the treatment of type 2 diabetic patients with ischemia peripheral artery disease may be as prophylactic agents preventing tissue damage by stimulating vasculogenesis. Therefore we determined if multipotent stromal cells (MSC) tagged with enhanced green fluorescent protein (EGFP) stimulated with or without exogenous EGF would improve vasculogenesis in ischemia hind limb of type 2 diabetic (db−/db−) mice.
Methods and Results: Isolated bone marrow from db−/db− mice showed an increase in oxidative stress and reduction in Akt compared to control. Ischemia was induced in the hind limb of db−/db− mice and control for 28 days. EGFP-MSC stimulated with or without exogenous EGF (10 ng/ml) for 24 hr were locally injected in the mice hind limb once a week for 4 weeks. After 4 weeks, blood flow measured with MoorLDI-Laser and angiogenesis assessed with X-ray were completely recovered in control mice compared to db−/db− mice. Interestingly db−/db− mice display a significant improvement of blood flow (60% and 96%) and vasculogenesis (61% and 98%) when treated with MSC or MSC pre-stimulated with exogenous EGF, respectively. Western blot analysis on hind limb muscles revealed an increase in phosphorylated Akt and VEGF receptor in db−/db− mice injected with MSC or MSC+EGF compared to non-treated db−/db− mice. Fluorescent microscopy images indicate that EGFP-MSCs differentiate into new microvessels. In vitro studies showed that adhesion and migration of MSC on cultured microvascular endothelial cells were elevated when MSC were pre-stimulated with EGF compared to non-stimulated MSC.
Conclusion: Our novel data provide evidence that in type 2 diabetes, MSC stimulated with EGF are able to significantly improve, better than MSC alone, the formation of microvessels in response to ischemia.