LAUSR

OBJECTIVE This study aims to investigate the correlation between the expression of miR-210 in peripheral blood and the number of peripheral endothelial progenitor cells (EPCs) in patients with type 2 diabetes mellitus (T2DM). We also determined the effect of miR-210 on EPC proliferation, adhesion, migration, tube formation, and apoptosis. METHODS A total of 32 patients with newly diagnosed T2DM (T2DM group) and 32 control subjects with normal glucose tolerance (NC group) were included. Peripheral blood samples were collected from each subject. The miR-210 level was determined by quantitative real-time polymerase chain reaction (qRT-PCR), and the number of positive EPCs indicated by CD34, CD133, and KDR expressions was detected by flow cytometry. After isolation, culture, and identification by fluorescent staining, EPCs were divided into four groups: NC group, untransfected type 2 diabetic group, miR-210 inhibitor NC group, and miR-210 inhibitor group. The expression of miR-120 in each group was detected by qRT-PCR, and the changes in the proliferation, adhesion, migration, tube formation, and apoptosis of EPCs after transfection with a miR-210 inhibitor were observed. RESULTS The expression level of miR-210 in the T2DM group (5.83 ± 1.26) was significantly higher than that in the NC group (5.83 ± 1.26) (t = 17.26, P < 0.001). The number of EPCs was significantly lower in the T2DM group (39.3 ± 12.6)/106 cells than that in the NC group (76.2 ± 10.7)/106 cells (t = 10.49, P < 0.001). Spearman's correlation analysis showed that the expression of miR-210 in the peripheral blood of patients with T2DM was negatively correlated with the number of EPCs (r = -0.558, P = 0.001). Multiple linear stepwise regression analysis showed that the peripheral blood level of miR-210 was an independent correlation factor that affected the number of EPCs (P < 0.001). After transfection with the miR-210 inhibitor, the proliferation, adhesion, tube formation, and migration levels of EPCs in miR-210 inhibitor group were higher than those in untransfected type 2 diabetic group and miR-210 inhibitor NC group, whereas the apoptosis rate was lower than that in these groups, and these results were statistically significant (P < 0.05). CONCLUSION The increased expression of miR-210 in patients with T2DM may be related to the decreased number and function of EPCs in peripheral blood.