A Preliminary Study On The Pathogenesis Of Immune Thrombocytopenic Purpura (ITP) By MiR-30a Mediating Th17 Cell Differentiation

Background and Objectives:Immune thrombocytopenic purpura(ITP)is one of the common hemorrhagic diseases in children.It is generally believed that autoantibodies destroying platelets,megakaryocyte maturation disorders and cellular immune imbalance all contribute to the pathogenesis of ITP.The specific mechanism of abnormal distribution of T cell subsets is not clear.In recent years,miRNAs have been found to play important roles in many autoimmune diseases.The miR-30a,which is abnormally expressed in T cells of ITP patients,was detected in a chronic ITP mouse model.Meantime,we detected the expression of RORyt and analyzed the correlation betweenmiR-30 and RORyt to prove that miR-30a is involved in the pathogenesis of ITP by affecting differentiation of Th17 cells.Finally we researched on the way how miR-30a effects immune imbalance by validating predicted target gene SOCS3.Methods:Firstly,we established a chronic ITP mouse model..The expression of miR-30a,ROR?t in the spleen mononuclear cells and correlation between them were detected.Secondly,the plasmid containing 3'UTR of the target gene and miRNA encoding plasmid were constructed.Luciferase fluorescence detection,Real-time fluorescent quantitative PCR(qPCR)and Western blot were used to verify whether SOCS3 was the target gene of miR-30a.Results:?The platelets of mice in experimental group decreased to below 20%of normal ones after 24 hours of injection of anti-mouse platelet serum(APS)and maintained for 14 days at least;?The expression of miR-30a and RORyt in the spleen mononuclear cells of experimental group were higher than those in the control group,and there was a positive correlation between them;?The activity of luciferase in PMDH-GFP-miR-30a and pMIR-report-UTR was significantly lower than that in pMDH-PGK-GFP empty plasmid and pMIR-report-UTR;?The expression of SOCS3 at mRNA and protein level was not different from that in the control group.Conclusions:?Chronic ITP mouse model was constructed successfully;?MiR-30a in spleen mononuclear cells of ITP mouse increased and was positive correlated with expression of ROR?t.contributing to the pathogenesis of ITP by affecting differentiation of'Th17 cells;?SOCS3 was able to bind to the target site of miRNA-30a,but might not play a biological function.