| Objective:To investigate the effect of umbilical cord mesenchymal stem cells(UCMSCs)transplantation on regulating chemokine(C-C motif)ligand 2(CCL2)of systemic lupus erythematosus.Methods:Levels of CCL2,Matrix metallo proteinases(MMPs)and interleukin(IL)-17 in serum,urine or the supernatant of bone marrow mesenchymal stem cells(BMMSCs)from SLE patients and healthy controls were detected by enzyme linked immune sorbent assay(ELISA)and Luminex methods.The percentages of CD4+CCR2+IL-17+cells were measured by flow cytometry.Female MRL/lpr mice were randomly divided into three groups,including the UCMSCs transplantation combined with CCL2 MAb treatment group,UCMSCs transplantation combined with IgG2B isotype control treatment group and non-treated MRL/lpr mice group.Female C57BL/6 mice were used as negative controls.The histopathology of the kidneys was observed by H&E staining.Urine proteins were measured by the Bradford method.ELISA and Luminex methods were used to measure the levels of the IgG,ANA,CCL2,MMPs and IL-17 in the serum or the supernatant of BMMSCs.The percentages of CD4+IL-17+cells and CD4+CCR2+cells were detected by flow cytometry.Naive T cells of spleen cells of mice were purified by magnetic activated cell sorting(MACS)and were activated to differentiate into Th17 cells.Th17 cells were co-cultured with UCMSCs in a transwell system.Recombination human CCL2 MAb,IgG2B isotype control,recombination human CCL2,MMP cleaved CCL2(mpCCL2),recombination human MMPs were added to treat Th17 cells,respectively.The percentages of CD4+CCR2+IL-17+cells were determined by flow cytometry.Results:Serum[(839.0 ± 160.5)pg/ml],urine[(881.8± 162.7)pg/ml]and the supernatant of BMMSCs[(22935±2304)pg/ml]levels of CCL2 in SLE patients were all significantly higher than those of healthy controls[(433.0 ± 31.0)pg/ml,(222.7±52.8)pg/ml,(8394 ±5125)pg/ml].MMP2(52633±1394pg/ml vs 35047±3666pg/ml,P<0.001),MMP3(251.8±271.3pg/ml vs 165.3±10.17pg/ml,P<0.01),MMP8(351.7±61.3pg/ml vs 144.7±23.7pg/ml,P<0.01)in serum were highly expressed in SLE patients compared with healthy controls.The percentages of CD4+CCR2+IL-17+cells in SLE patients were significantly increased(0.482±0.188%vs 0.0800±0.054,P<0.01).Kidneys of lupus mice were inflammation.Urine protein[(0.5799 ±0.0176)μg/μl],IgG[(245.7 ± 13.9)ng/ml],ANA[(839.0± 160.5)U/ml],CCL2[(69.77 ±39.30)pg/ml]and IL-17[(18.07±8.22)pg/ml]levels were most decreased in UCMSCs transplantation combined with CCL2 MAb treatment group.The percentages of IL-17 and CCR2 in CD4+cells were also decreased significantly in UCMSCs transplantation combined CCL2 MAb treatment group compared with non-treated MRL/lpr mice group(P<0.05,P<0.001).The expressions of MMP2(321045±35443pg/ml vs 615291±71486pg/ml,P<0.05)in the serum of treated mice group was decreased significantly.However,MMP2(20042 ± 1170pg/ml vs 611.3±182.0pg/ml,P<0.0001),MMP8(12096± 492.6pg/ml vs 11742±3221pg/ml,P<0.01),MMP9(42091± 1749pg/ml vs 34199±16794pg/ml,P<0.01)in the supernatant of BMMSCs of the treated mice groups were all increased significantly.Results of the in vitro studies demonstrated that the percentages of CD4+CCR2+IL-17+cells of lupus mice were down-regulated in the mpCCL2 treatment group and UCMSCs co-cultured group compared with blank control groups.Conclusion:The benefit effects of UCMSCs transplantation on SLE may via secreting MMPs,which can modify CCL2 by converting it from an agonist to an antagonist of Th17 activation and suppress Th 17 finally. |
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