MicroRNA-378 protects human umbilical vein endothelial cells from injuries by soluble CD226 through down-regulating the expression of soluble CD226 in natural killer cells

This study aimed to determine the expression of microRNA (miRNA or miR)-378 in peripheral blood from patients with pregnancy-induced hypertension (PIH), and to try to understand its effect on vascular endothelial injuries induced by PIH. The study included 33 PIH patients. Quantitative real-time polymerase chain reaction was used to determine the expression of miR-378 in peripheral blood and NK cells. NK cells were transfected with miR-378 mimics and its negative control. Bioinformatics was used to predict the potential target gene of miR-378. Flow cytometry and Western blotting were performed to identify changes in the expression of CD226 protein. By co-culturing HUVECs with NK cells, the effects of miR-378 and CD226 on the proliferation, migration and apoptosis of HUVECs were evaluated. The results showed that the expression of miR-378 in peripheral blood was down-regulated with the progression of PIH. The expression of miR-378 was reduced in innate immune NK cells from peripheral blood of PIH patients. miR-378 negatively regulated the expression of CD226 in NK cells, and CD226 is a target gene of miR-378. miR-378 inhibited the expression and secretion of soluble CD226 by NK cells. miR-378 regulated the proliferation, migration and apoptosis of HUVECs by affecting the levels of soluble CD226 expressed by NK cells. The present study demonstrates that miR-378 is down-regulated in peripheral blood and NK cells from patients with PIH, and negatively correlated with the development of PIH. miR-378 protects HUVECs from injuries by soluble CD226 through down-regulating the expression of soluble CD226 in NK cells.