Effect and Mechanism of Bone Marrow-derived Mesenchymal Stem Cell-conditioned Medium on Diabetic Foot Ulcers in Rats
Objective To explore the effect and mechanism of bone marrow-derived mesenchymal stem cell-conditioned medium(MSC-CM)on diabetic foot ulcer(DFU)in rats.Methods The model of diabetes mellitus type 2(T2DM)were induced by high fat diet and intraperitoneal injection of STZ in SD rats.DFU models were made by operation on hind limbs in diabetic rats.The rats were di-vided into four groups:normal control(NC)group,diabetes mellitus control(DM-C)group,MSC-CM group and mesenchymal stem cell(MSC)group,6 rats in each gruop.The MSC-CM group was injected with bone marrow-derived MSC-CM around ulcers.MSC group was injected with bone marrow-derived MSC.The other two groups were treated with injection of PBS.After the treatment,wound clousure,re-epithelialization(thickness of the stratum granulosums of the skin was detected by HE staining),cell proliferation(ki-67 was detected by immunohistochemistry),angiogenesis(CD31 was detected by immunofluorescence),autophagy(LC3B was detected by immunofluorescence and Western blot,autolysosome was observed by electron microscopy)and pyroptosis(IL-1 β,NLRP3,caspase-1,GSDMD and GSDMD-N were detected by Western blot)in ulers were evaluated.Results After the treatment,the wound area,IL-1β,caspase-1,GSDMD and GSDMD-N in MSC-CM group were lower than those in DM-C group.Thickness of the stratum gran-ulosums of the skin,ki-67,CD31 and LC3B in MSC-CM group were higher than those in DM-C group.The injection of MSC-CM to rats with DFU enhanced the wound healing process by accelerating wound closure,promoting cell proliferation and angiogenesis,enhan-cing cell autophagy and reducing cell pyroptosis in ulcers.Conclusion MSC-CM could be a novel cell-free therapeutic approach to treat rats with DFU accelerating the wound healing process.