Transplantation of Mesenchymal Cells Improves Peripheral Limb Ischemia in Diabetic Rats

Adipose tissue-derived mesenchymal stromal cells (ADSCs) are a prominent cellular source for regenerative medicine. We tested whether transplantation of ADSCs into the ischemic muscular tissue of diabetic animals would attenuate impaired cell metabolism and microcirculatory function. We induced unilateral hind limb ischemia in male streptozotocin-treated rats and nondiabetic controls. One day after femoral artery ligation, six rats per group were intramuscularly injected allogeneic ADSCs (10⁶–10⁷–10⁸ cells/mL); or conditioned media from ADSC cultures (CM); or saline; or allogeneic fibroblasts (10⁷ cells/mL); or nonconditioned medium. Rats underwent magnetic resonance angiography; short time inversion recovery (STIR) edema-weighed imaging; proton MR spectroscopy (¹H-MRS); immunoblotting and immunofluorescence on both hind limbs for 4 weeks. T₁-weighted and STIR images showed tissue swelling and signal hyperintensity, respectively, in the ischemic tissue. The mean total ratio of creatine/water for the occluded limbs was significantly lower than for the nonoccluded limbs in both nondiabetic and diabetic rats. ADSC and CM groups had greater recovery of tCr/water in ischemic limbs in both diabetic and nondiabetic rats, with increased expression of α-sarcomeric actinin, vascular endothelial growth factor and hepatocyte growth factor, as well as increased vessel density. ADSCs improve ischemic muscle metabolism and increase neovasculogenesis in diabetic rats.