Transplantation of erythropoietin gene-transfected umbilical cord mesenchymal stem cells as a treatment for limb ischemia in rats.

The aim of this study was to investigate the mechanisms of erythropoietin (EPO)-transfected umbilical cord mesenchymal stem cells (UC-MSCs) in the treatment of rats with ischemic limb and provide a theoretical basis for optimization of UC-MSC transplantation. Sixty SD rats were randomly divided into four groups: ischemia control group, EPO treatment group, UC-MSCs treatment group, EPO gene transfected UC-MSC treatment groups (15 rats in each group). The left femoral hind artery and its branches were ligated to develop hind limb ischemia in male SD rats. Five points were injected in the adductor and gastrocnemius muscles with medium, cDNA3-EPO gene DNA-liposome complex solution or UC-MSCs in control groups and EPO-transfected-UC-MSCs in the experimental group. Western blot confirmed in vitro EPO expression in EPO gene-transfected human UC-MSCs. Arterial angiography at 4 weeks post-transplantation showed no development of blood vessels in the control group and moderate angiogenesis in the EPO- and UC-MSC-treated groups. However, a large number of freshmen angiogenesis and abundant collateral circulation was observed in the EPO-transfected-UC-MSC-treated experimental group. Rat capillary density measurement results confirmed the angiographs quantitatively and showed no statistically significant difference between EPO- and UC-MSC-treated groups (P > 0.05). CM-Dil-positive cell numbers were (0 ± 0.00), (0 ± 0.00), (32.46 ± 6.68), (59.64 ± 10.38)/HP (P < 0.05). RT-PCR detected that the in vivo mRNA expression of the EPO gene was relatively higher in the EPO-transfected-UC-MSC-treated group than the EPO-treated group (0.79 ± 0.06 vs 0.19 ± 0.04, P < 0.05). Thus, this study revealed that using UC-MSCs as vector in gene therapy for limb ischemia facilitates stable and effective expression of EPO compared to direct gene injection.