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

The renin-angiotensin system (RAS) serves an essential role in hypertension. MicroRNAs (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 (HUVECs) 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 HUVECs 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. HUVECs 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 HUVECs via the suppression of miR-133a. Furthermore, siPRR efficiently decreased the Ang II-induced apoptosis.