Downregulated microRNA-133a induces HUVECs injury: Potential role of the (pro) renin receptor in angiotensin II-dependent hypertension

Abstract

The renin-angiotensin system (RA S) serves an essential role in hypertension. MicroRNA s (miRs) have been reported to be important regulators in angiotensin (Ang) II- dependent hypertension. We aimed to explore the roles of Ang II and miR- 133a in the mechanism underlying hypertension. Human umbilical vein endothelial cells (HUVEC s) were identified by immunofluorescence staining. Cell viability and miR- 133a expression under the inhibition of Ang II of various concentrations were determined by an MTT assay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively. The effects of HUVEC s transfected with miR- 133a mimic or inhibitor on Ang II- induced apoptosis were measured using flow cytometry. The potential targeting of miR- 133a to the 3' untranslated region of (pro) renin receptor (PRR) was assessed using TargetScan and a dual-luciferase assay. The effects of PRR interference using small interfering (si)RNA on PRR expression and the rate of apoptosis were determined by RT-qPCR, western blotting and flow cytometry, respectively. Ang II at a concentration of 10-5 M significantly inhibited the cell viability (P<0.05) and miR-133a expression (P<0.01); Downregulation of miR-133a suppressed cell viability. HUVEC s transfected with miR- 133a mimic reduced the rate of Ang II- induced apoptosis from 21.99 to 12.38%, but miR- 133a inhibitor promoted Ang II-induced apoptosis (apoptosis rate, 28.9%). PRR was predicted to be a target gene of miR- 133a. Transfection with siPRR decreased the apoptotic rate in Ang II + negative control and Ang II + miR- 133a inhibitor group to 11.39 and 12.94%, respectively. Our findings also suggested that Ang II promoted PRR expression to enhance the apoptotic rate of HUVEC s via the suppression of miR-133a. Furthermore, siPRR efficiently decreased the Ang II- induced apoptosis.