Effect Of Exosomes Loaded MiR-126 On Early Steroid-induced Avascular Necrosis Of Femoral Head In Rat

ObjectiveTo investigate the relative the effects of the exosomes derived from mesenchymal sthem cells overexpressed miR-126(miR-126-MSC-Exo)on early steroid-induced avascular necrosis of femoral head(SANFH).MethodsIsolate exosomes derived from mesenchymal sthem cells(MSC-Exo)and miR-126-MSC-Exo by ultracentrifugation.The relative expression of miR-126 in miR-126-MSC-Exo and MSC-Exo is quantified by Quantitative Real-time PCR(qRT-PCR).The well-growing HUVECs were treated with miR-126-MSC-Exo,MSC-Exo and equal amount of PBS,respectively.The proliferation,migration and capillary network formation of HUVECs were detected by MTT,scratch test and tube formation assay,respectively.Western blotting was used to detect the expression of vascular endothelial growth factor A(VEGFA)in HUVECs.early steroid-induced avascular necrosis of femoral head(ANFH)models of sprague dawley(SD)rat were injected with miR-126-MSC-Exo,MSC-Exo and PBS,respectively.After 6 weeks,CD31 immunofluorescence staining and Micro-CT scanning were performed on the region of the femoral head to evaluate the therapeutic effect of miR-126-MSC-Exo.ResultsIn vitro,the expression level of VEGFA was also significantly higher than MSC-Exo group,and compared with MSC-Exo group,miR-126-MSC-Exo group significantly promoted the proliferation,migration and tube formation of HUVECs,the difference was statistically significant(P < 0.05).In vivo,the number of CD31 immuno-fluorescence labeled vessels in the femoral head in group miR-126-MSC-Exo was significantly higher than that in the MSC-Exo group and the model group(P < 0.05).Besides,the Micro-CT scan of the femoral head necrosis region showed that the Tb.Th,Tb.Sp,Tb.N and BV/TV value of the miR-126-MSC-Exo group was significantly higher than that of the MSC-Exo group and the model group(P < 0.05).ConclusionmiR-126-MSC-Exo can promote the function of endothelial cells,improve the blood supply in the femoral head area and enhance the deposition of bone,and have significant therapeutic effect on the SANFH in rats.