| Objective: The low homing rate of exogenous MSCs to target tissues is a key obstacle to the therapeutic effect of MSCs.This study aims to investigate the mechanisms of regulating the migration and homing of MB-e MSCs,and to provide a theoretical basis for further exploring effective methods to promote the migration and homing of MB-e MSCs to damaged ovaries,thereby enhancing the therapeutic effect of MB-e MSCs on POF.Methods: The expression of CXCR4 receptor on the surface of MB-e MSCs was detected through western blotting.The expression of CXCR4 of MB-e MSCs was knocked down using RNA interference(RNAi)technology.Western blotting was used to detect the knockdown efficiency of CXCR4.The effects of SDF-1concentration and CXCR4 receptor expression on MB-e MSCs migration in vitro were examined by Transwell cell migration assay.C57BL/6 mice were intraperitoneally injected with 0,5,10,or 15 mg/kg epirubicin for 7 consecutive days respectively.The general condition was observed and recorded everyday.Estrous cycles were observed through vaginal exfoliation cytology.The morphology of ovarian tissue was observed through HE staining and the number of follicles was counted.Serum AMH and FSH levels were detected through ELISA.All the indicators of mice mentioned above were to identify the success of the POF model establishment.The effect of epirubicin treatment on the local SDF-1 concentration in mouse ovaries was displayed through Western blotting.MB-e MSCs were transplanted via the tail vein into epirubicin-induced POF mice.The effects of local ovarian SDF-1 concentration and CXCR4 receptor expression on MB-e MSCs homing to damaged ovaries were studied by detecting changes of CXCR4 protein expression in ovaries of POF mice.Results: CXCR4 receptor was expressed on the surface of MB-e MSCs.The relative expression of CXCR4 protein in sh1/sh2-MB-e MSCs was significantly reduced after RNAi,respectively 0.69±0.64 times(P=0.001)and 0.46±0.02 times of MB-e MSCs(P=0.000),which suggested that CXCR4 expression on MB-e MSCs was significantly inhibited by sh RNA interference.The results of Transwell cell migration experimentassay suggested that the migration number of MB-e MSCs increased in accordance with the increased level of SDF-1 concentration under the chemotaxis of 0-200ng/m L SDF-1(P<0.05),and reached the maximum at 100ng/m L.After blocking the CXCR4 receptor,the migration number of MB-e MSCs was significantly reduced(P=0.000).After receiving continuous i.p.injection of epirubicin,mice in E-10 group displayed tarnished hair,a decrease in food intake,body weight,activity,and showed slow response to external stimuli.Estrous cycles disappeared and were arrested in proestrum or diestrum.The serum AMH level was decreased while the serum FSH level was increased.Uterine and ovarian tissue were atrophied.Types and numbers of antral and developing follicles were decreased,and the number of oocytes collapsed was increased,which suggested that the POF model was successfully established.The expression of SDF-1 protein in ovaries of mice accepted epirubicin treatment was upregulated in accordance with the increase of epirubicin concentration.Then POF mice were injected with MB-e MSCs through the tail vein.The relative expression of CXCR4 protein in ovaries of POF mice was significantly increased 2 weeks after transplantation(P<0.0001).When CXCR4 receptor on MB-e MSCs was blocked,the expression of CXCR4 protein in ovaries of POF mice was significantly decreased(P<0.001).All the differences were statistically significant.Conclusions: Epirubicin treatment can induce POF in C57BL/6 mice,increase the concentration of SDF-1 in damaged ovaries.The expression of ovarian CXCR4 protein increases in epirubicin-induced POF mice after MB-e MSCs transplantation.SDF-1 can bind to the CXCR4 receptor on the surface of MB-e MSCs,which induces the migration and homing of MB-e MSCs in POF mice through the SDF-1/CXCR4 axis. |
PDF Full Text Request