Restoring the Angiogenic Capacity of the Human Diabetic Adipose Derived Stem Cells Primed with Deferoxamine as a Hypoxia Mimetic Agent: Role of HIF-1α

Abstract

Pupose: Insufficient angiogenesis is associated with serious diabetic complications. Recently, adipose-derived mesenchymal stem cells (ADSCs) are known to be a promising tool causing therapeutic neovascularization. However, the overall therapeutic efficacy of these cells is impaired by diabetes. This study aims to investigate whether in vitro pharmacological priming with deferoxamine, a hypoxia mimetic agent, could restore the angiogenic potential of diabetic human ADSCs. Methods: Diabetic human ADSCs were treated with Deferoxamine and compared to normal and nontreated diabetic ADSCs for the expression of HIF-1α, VEGF, FGF-2 and SDF-1α, at mRNA and protein levels, using qRT-PCR, western blotting and ELISA assay. Activities of matrix metalloproteinases -2 (MMP-2) and -9 (MMP-9) were measured using a gelatin zymography assay. Angiogenic potentials of conditioned media derived from normal, Deferoxamine treated, and non-treated ADSCs were determined by in vitro scratch assay and also three-dimensional tube formation assay. Results: It is demonstrated that deferoxamine (150 and 300 μM) stabilized hypoxia inducible factor 1-alpha (HIF-1α) in primed diabetic ADSCs. At the concentrations used, deferoxamine did not show any cytotoxic effects. In deferoxamine treated ADSCs, expression of VEGF, SDF-1α, FGF-2 and the activity of MMP-2 and MMP-9 were significantly increased compared to nontreated ADSCs. Moreover, deferoxamine increased the paracrine effects of diabetic ADSCs in promoting endothelial cell migration and tube formation. Conclusion: Deferoxamine might be an effective drug for pharmacological priming of diabetic ADSCs to enhance the expression of proangiogenic factors noted via HIF-1α accumulation. In addition, impaired angiogenic potential of conditioned medium derived from diabetic ADSCs was restored by deferoxamine.