Endothelial MicroRNA-214 Confers Angiotensin II Hypertension by Targeting eNOS in Mice.

Introduction: MicroRNAs have been increasingly recognized for their roles in cardiovascular diseases. Among these microRNAs, miR-214 was reported to be involved in hypertension. However, the role of endothelial miR-214 in hypertension is still unknown. The aim of this study was to determine the role of cell-specific miR-214 on regulating blood pressure, as well as the potential mechanisms.

Methods: We detected the levels of miR-214 in hypertensive mice and cultured mouse aortic endothelial cells (MAECs). In addition, mouse miR-214 inhibitor, miR-214 mimics, vascular endothelial cell-specific miR-214-deficient mice, smooth muscle cell-specific miR-214-deficient mice, renal proximal tubule cell-deficient mice, and various cellular and molecular techniques were employed to define the role of miR-214 in Ang II-induced hypertension.

Results: In mice and MAECs, Ang II significantly enhanced miR-214 levels, and anti-miR-214 markedly attenuated Ang II hypertension in line with enhanced eNOS/p-eNOS in aorta. Then, we generated vascular endothelial cell-specific miR-214 knockout mice and found an antihypertensive phenotype in endothelial miR-214 conditional knockout mice after Ang II treatment. In normotensive animals and MAECs, exogenous miR-214 administration reduced eNOS expression at protein and mRNA levels; in contrast, anti-miR-214 played an opposite role in regulating eNOS. By luciferase assay, our results confirmed that eNOS was a direct target gene for miR-214 in endothelial cells. However, smooth muscle cell-specific or renal tubular cell-specific deletion of miR-214 did not alter Ang II-induced hypertension.

Conclusion: Our findings suggested that endothelial miR-214 promoted Ang II hypertension by targeting eNOS in mice, which increased the understanding on the pathogenic mechanism of hypertension.