Effect of different transplantations with bone-marrow derived mesenchymal stem cells on diabetic foot ulcers in rats / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To assess the therapeutic effect of treating diabetic foot ulcers (DFUs) in rats by subcutaneously transplanting around the wounds and intramuscularly into the leg with bone marrow derived mesenchymal stem cells (BM-MSCs).@*METHODS@#BM-MSCs from male Wistar rats were cultured by the whole bone marrow adherence method until the third generation. The BM-MSCs were labeled by 4,6-diamino-2-phenylindole (DAPI) in vitro. Forty-eight male Wistar rats were randomly divided into 4 groups group A (n=12), rats with DFUs receiving BM-MSCs subcutaneous transplantation; group B (n=12), rats with DFUs receiving BM-MSCs intramuscular transplantation; group C (n=12), nondiabetic rats with foot ulcers; and group D (n=12), rats with DFUs receiving no BM-MSCs. A diabetic rat model was induced by intraperitoneally injecting streptozotocin (STZ). Then DFU model was established by removing a 3 mm × 7 mm rectangular full-thickness skin on the 2 back dorsum pedis surfaces. On day 2, 5, 8 and 11 after the transplantation, the rate of wound closure was raised; trace of DAPI labeled-BM-MSCs in the wound tissues was observed on frozen sections and the thickness of granulation tissues was detected by HE stain. Immunohistochemistry was performed to detect the expression of CD31 and Ki-67. The expression of vascular endothelial growth factor (VEGF) in the wound tissues was detected by ELISA and RT-PCR.@*RESULTS@#The wound closure in group C was faster than in other groups (P<0.05). The rate of wound healing in group B was higher than group A on day 11 (P<0.05). The intensity and area of the fluorescence in group B were higher than group A on day 2 and 5 on the frozen sections. HE stain showed that the granulation tissue formation in group B was thicker than group A on day 5. Immunohistochemistry of CD31 demonstrated that the mean number of small blood vessels in group B was more than in group A on day 5 and 8 (P<0.05). Immunohistochemistry of Ki-67 showed it had no difference between group A and group B. ELISA and RT-PCR revealed that the expression level of VEGF in the wound tissues in group B was higher than in group A on day 8 and 11 (P<0.05, P<0.001, respectively).@*CONCLUSION@#Both transplantations promote the wound healing of DFUs in rats. The intramuscular transplantation into the leg shows a better persistence and a higher expression level of VEGF in the wound tissues at later stages.