The downregulation of microRNA-4281 inhibits FOXP3 expression and induces Treg/Th17 immune imbalance in immune thrombocytopenic purpura
The purpose of this study was to investigate the role of miR-4281 in immune thrombocytopenic purpura(ITP)and its underlying mechanism.Differentially expressed miRNAs in ITP were searched by using GEO database.Newly diagnosed ITP patients,treatment-effective ITP patients and healthy subjects were collected.Venous blood was obtained and peripheral blood mononuclear cells(PBMCs)and CD4+T cells were separated.Real-time quantitative PCR was used to detect the expression of miR-4281 and other factors in cells.Flow cytometry was conducted to analyze the rate of CD4+CD25+FOXP3+Tregs and Th17 cells.Pearson correlation coefficient method was used to test the relationship between miR-4281 expression level and various factors.Bioinformatics analysis revealed an abnormal expression of miR-4281 in ITP.Compared with healthy subjects and treatment-effective ITP patients,the expression level of miR-4281 in newly diagnosed ITP was decreased.The expression level of miR-4281 in PBMCs of ITP patients was positively correlated with Tregs content and Treg/Th17,while negatively correlated with Th17 cell content.miR-4281 can promote the differentiation of Tregs cells and inhibit the differentiation of Th17.Furthermore,the expression level of miR-4281 is positively correlated with the expression level of FOXP3.Taken together,the expression level of miR-4281 is reduced in ITP.This decrease can inhibit the expression of FOXP3,cause Treg/Th17 immune imbalance,and promote the progression of ITP.