miR-125b-5p修饰脐带间充质干细胞对系统性红斑狼疮的免疫调控机制

Immunomodulatory mechanism of umbilical cord mesenchymal stem cells modified by miR-125b-5p in systemic lupus erythematosus

目的:研究miR-125b-5p修饰脐带间充质干细胞(umbilical cord mesenchymal stem cells, UC-MSCs)对系统性红斑狼疮(systemic lupus erythematosus, SLE)的免疫调控作用机制。方法:实时荧光定量PCR检测miR-125b-5p在UC-MSCs和SLE患者、健康体检者外周血单个核细胞中的表达水平;Annexin V-FITC/PI凋亡检测试剂盒检测miR-125b-5p对UC-MSCs的凋亡影响;每周对MRL/lpr小鼠进行尾静脉注射UC-MSCs, 5周后流式细胞术检测各组小鼠脾细胞T淋巴细胞亚群分化情况;ELISA法检测各组MRL/lpr小鼠血清中白细胞介素(interleukin, IL)-4和IL-17A表达水平;苏木精-伊红染色法观察MRL/lpr小鼠肺和肾组织病理变化。结果:与健康对照组相比,SLE患者外周血单个核细胞中miR-125b-5p的表达水平显著下调(P<0.01);与UC-MSCs相比,miR-125b-5p转染UC-MSCs组miR-125b-5p的表达水平显著上调(P<0.01)。miR-125b-5p转染UC-MSCs 48 h可显著提高细胞存活率(P<0.01);与未处理的MRL/lpr小鼠组相比,miR-125b-5p修饰UC-MSCs对MRL/lpr小鼠脾脏Th17细胞分化具有明显的下调作用(P<0.05),且在小鼠血清中IL-4表达水平明显升高(P<0.05),IL-17A表达水平明显减低(P<0.05)。经miR-125b-5p修饰的UC-MSCs治疗后,MRL/lpr小鼠肺和肾组织内炎性细胞浸润和微血栓减少。结论:miR-125b-5p修饰UC-MSCs对SLE具有免疫调控作用。

Objective:To investigate the mechanism of immunomodulatory effects of umbilical cord mesenchymal stem cells(UC-MSCs)modified by miR-125b-5p on systemic lupus erythematosus(SLE).Methods:The expression level of miR-125b-5p was detected by real-time fluorescence quantitative PCR in UC-MSCs and peripheral blood mononuclear cells(PBMCs)from SLE patients and health checkers.Annexin V-FITC/PI apoptosis detection kit was used to detect the effect of miR-125b-5p on apoptosis of UC-MSCs.MRL/lpr mice in each group were injected with UC-MSCs via tail vein,and T-lymphocyte subsets in the spleen of the MRL/lpr mice were detected by flow cytometry after 5 weeks.The expression levels of interleukin(IL)-4 and IL-17A in serum of MRL/lpr mice were detected by ELISA.Hematoxylin-eosin staining was used to observe the pathological manifestations of the lungs and kidneys of the MRL/lpr mice.Results:miR-125b-5p was significantly down-regulated in PBMCs of SLE patients compared with healthy controls(P<0.01).Compared with the UC-MSCs group,the expression of miR-125b-5p in UC-MSCs modified by miR-125b-5p group was increased(P<0.01).The survival rate of UC-MSCs was significantly increased by miR-125b-5p(P<0.01).Compared with the untreated group of MRL/lpr mice,the expression level of IL-4 in serum was increased(P<0.05);the expression level of IL-17A was decreased(P<0.05);the proportion of Th17 cells in the spleen of MRL/lpr mice was decreased(P<0.05);the inflammatory cells infiltration and micro-thrombosis of lungs and kidneys of MRL/lpr mice were significantly reduced in the UC-MSCs modified by miR-125b-5p treatment group.Conclusion:UC-MSCs modified by miR-125b-5p have immunomodulatory effects on systemic lupus erythematosus.