Study On The Profiling Of MicroRNA Expression In CD4+T Cells From Patients With Systemic Lupus Erythematosus

Objective:To investigate the role of microRNA (miRNA) in the pathogenesis of Systemic lupus erythematosus (SLE) through detecting the miRNA expression profiling in CD4+T cells from SLE patients.Methods:(1)Peripheral blood mononuclear cells (PBMCs) were isolated from the peripheral venous blood of SLE patients and healthy donors by density gradient centrifugation. CD4+T cells were isolated using microbeads and protocols provided by the manufacturer.(2) Total RNA and protein were isolated with RNA/protein isolation kits.(3)miRNA expression profiling were detected by microarray.(4)Altered microRNA were confirmed by Stem-loop quantitative real-time polymerase chain reaction (stem-loop RT-PCR).(5)DNMT1 protein level was detected by western blot.Results:(1)According to the microarray, miR-126, miR-1246,miR-1308, miR-574-5p, miR-638,miR-7 were significantly up-regulated in CD4+T cells from SLE patients (P<0.01),miR-142-3p, miR-142-5p, miR-197, miR-186, miR-31 were significantly down-regulated (P<0.01)compared to healthy controls.(2) Stem-loop RT PCR confirmed that miR-126 was significantly up-regulated (P<0.001)and miR-142-3p was significantly downregulated (p=0.001) in CD4+T cells from SLE patients.But there was no difference for miR-142-5p and miR-638 between SLE patients and healthy controls(p=0.86,p=0.58)(3) The DNMT1 protein expression was significantly lower in SLE patients CD4+T cells than that in controls (P<0.05)and was negtively correlated with miR-126 expression level in SLE CD4+T cells(r=-0.628, P=0.012)Conclusion:These data suggests that aberrant miRNA expression occurs in CD4+T cells of patients with SLE, miR-126 may involve in pathogenesis of SLE by regulating DNMT1.