Abstract:Background and Aims Stromal cell-derived factor-1α (SDF-1α) is a chemotactic factor that directs cell migration. Studies have shown that mesenchymal stem cells (MSCs) can migrate along the SDF-1 gradient to the site of tissue injury and participate in tissue repair. However, there is currently a lack of in vivo studies on the tissue repair of diabetic ischemic lower limbs using SDF-1α-induced adipose-derived stem cells (ASCs). Therefore, this study was conducted to investigate the effect of SDF-1α on the migration of rat adipose-derived stem cells (rASCs) to the muscle tissue of diabetic ischemic rat lower limbs and its impact on tissue repair.Methods The rASCs were isolated and cultured from the adipose tissue of SD rats. Cell morphology was observed, and the differentiation capacity towards adipocytes, chondrocytes, and neurons was evaluated. Then, the rASCs were transfected and labeled with green fluorescent protein (GFP) using adenovirus. Diabetes was induced in rats using the streptozotocin (STZ) method, and the right femoral artery of the rats was ligated to induce lower limb ischemia. The rats were randomly divided into two groups and injected with rASCs via the tail vein. The SDF-1α protein was injected into the midsection of the affected limb muscle in one group (SDF-1α+rASCs group), while the other group was injected with an equal amount of phosphate-buffered saline (rASCs group). Blood flow measurements of the rat lower limbs were conducted at weeks 1 and 2 after treatment, and the ischemic limb-to-contralateral limb blood flow ratio was calculated and compared. At week 4, the rats were euthanized, and muscle tissue from the ischemic region was subjected to HE staining to observe the arrangement of muscle tissue in different treatment groups. Immunofluorescent staining using factor Ⅷ (FⅧ) as a marker for microvessels was performed to observe the distribution of FⅧ and GFP in the tissues under a fluorescence microscope.Results The cultured cells exhibited spindle or multiangular growth and had the ability to differentiate into adipocytes, chondrocytes, and neurons, confirming their identity as rASCs. The blood flow measurements of the diabetic ischemic rat lower limbs showed that the ischemic limb-to-contralateral limb blood flow ratio was significantly higher in the SDF-1α+rASCs group than in the rASCs group at week 1 (0.33±0.03 vs. 0.26±0.02, P=0.016), and this difference further increased at week 2 (0.60±0.02 vs. 0.47±0.01, P=0.050). HE staining revealed a more orderly arrangement of muscle tissue in the SDF-1α+rASCs group at week 4. Immunofluorescent staining showed that the number of rASCs in the skeletal muscle tissue of the SDF-1α+rASCs group was significantly higher than that in the rASCs group at week 4 (P<0.05), and overlapping red fluorescence (FⅧ) and green fluorescence (rASCs) were observed.Conclusion Increasing the concentration of SDF-1α at the site of ischemia can effectively increase the number of rASCs migrating to the affected area, resulting in optimized blood flow perfusion and significant improvement in muscle tissue repair. In addition, the differentiation of rASCs into endothelial cells may be one of the key mechanisms.