The Expression And Relationship Of MicroRNA-155 And Regulatory T Cells In Type 2 Diabetic Patients With Retinopathy

ObjectiveTo detect the expression levels of microRNA-155 (miR-155), regulatory T cells (Tregs) and plasma TGF-? in peripheral blood mononuclear cells (PBMC), and to investigate whether miR-155 involves in the pathogenesis of type 2 diabetic retinopathy (DR) by regulating Tregs.MethodsWe selected 58 DR patients[20 cases with background diabetic retinopathy(BDR),18 cases with proliferative diabetic retinopathy(PDR),20 cases with non-diabetic retinopathy(NDR)] and 20 healthy controls(NC). Flow cytometry was performed to detect the percentages of Tregs. Real-time RT-PCR was employed to analyze the expressions of miR-155. Plasma concentrations of TGF-? was measured by ELISA.,Results1.The percentages of Treg cells decreased obviously in BDR, PDR and NDR patients(all P<0.05)compared with NC, Kruskal-Wallis test in BDR, PDR, NDR subsets revealed that the differences were significant(all P<0.05).2.MiR-155 increased obviously in BDR, PDR and NDR patients(all P<0.05)compared with NC; meanwhile, one-way ANOVA test in BDR, PDR, NDR subsets revealed that the differences were significant(all P<0.05); additionally, multiple comparison in BDR, PDR,NDR and NC subsets revealed that the differences were significant(all P<0.05).3.Plasma TGF-? levels decreased markedly in BDR, PDR and NDR patients(all P<0.05). The same text to above revealed that the differences were also significant(all P<0.05).4.MiR-155 expression levels were negatively correlated with Treg cells and TGF-? levels(r value are -0.516,-0.486 respectively; both P<0.01).Conclusion1.The percentages of Tregs of patients with type 2 diabetic retinopathy were significantly lower than the healthy control group. And with the development of the disease showed dynamic changes. The percentages of Tregs in the patients with proliferative diabetic retinopathy is decrease more obvious. Above suggest that autoimmune factors changes caused by abnormalities of Tregs may participate in the development of diabetic retinopathy.2.The expression of miR-155 in PBMC of patients with type 2 diabetic retinopathy were significantly increased than the healthy control group. And miR-155 expression levels were negatively correlated with Tregs and TGF-? levels. All of above indicate that increased expression of miR-155 may regulate the expression of regulatory T cells by inhibited the expression of TGF-?, and probably play an important role on the pathogenesis of type 2 diabetic retinopathy.