Exposure to diabetes in utero has been shown to program offspring toward cardiometabolic disease and diabetes (DM). Alteration of fetal microRNA expression is a potential mechanism that mediates the effects of maternal conditions on the fetus. In previous work, we have shown that miRNA-126 expression is increased in umbilical vein endothelial cells (HUVEC) and in cord blood from infants born to mothers with DM. In this study we evaluated the capacity of miRNA-126 to target IRS1 mRNA by binding to a complementary sequence in the 3’UTR. A commercially available plasmid (SwitchGear Genomics) containing the 3’UTR of IRS1 with a luciferase reporter was co-transfected along with miRNA-126 into HEK-293A cells. Luciferase expression was reduced by 1.5-fold with the addition of miR-126 as compared to the controls (Figure 1). As confirmation, the sequence predicted to target miR-126 was cloned from HUVEC into the pmirGLO vector (Promega) also containing luciferase reporter. With the addition of miR-126, luciferase expression was reduced by 2.2-fold. The data suggest that IRS1 is a target for miR-126. As miR-126 is increased in HUVEC of infants born to mothers with DM, we postulate that IRS1 protein will be decreased, potentially impacting downstream signaling within the cell, as well as endothelial function. Future studies are planned to evaluate the impact of miR-126 on endothelial function.
J.B. Tryggestad: None. A.M. Teague: None. S. Chernausek: Advisory Panel; Self; Novo Nordisk Inc..
