MicroRNA‑138‑5p drives the progression of heart failure via inhibiting sirtuin 1 signaling

Abstract

The present study aimed to investigate the regulatory effects of microRNA‑138‑5p (miR‑138‑5p) and sirtuin 1 (SIRT1) on the progression of heart failure (HF). The binding association between miR‑138‑5p and SIRT1 was assessed by the dual‑luciferase reporter assay. By conducting reverse transcription‑quantitative polymerase chain reaction and Western blotting, relative levels of SIRT1 and p53 regulated by miR‑138‑5p were detected. In vitro HF models were generated by hydrogen peroxide (H₂O₂) induction in AC‑16 and human cardiomyocyte (HCM) cells, followed by detection of the regulatory effects of SIRT1 on cell apoptosis and p53 expression. MiR‑138‑5p was negatively correlated with the SIRT1 level in cardiomyocytes. By recognizing and specifically targeting SIRT1 3'‑untranslated region (3'‑UTR), miR‑138‑5p decreased the translational level of SIRT1 and inhibited its enzyme activity, thereby decreasing the deacetylation level of p53. Through downregulating SIRT1 and activating p53 signaling, miR‑138‑5p induced apoptosis in H₂O₂‑induced AC‑16 and HCM cells. By contrast, knockdown of miR‑138‑5p in the in vitro HF models significantly protected the cardiomyocytes. SIRT1 contributed toward alleviate HF by inhibiting cardiomyocyte apoptosis via enhancing the deacetylation level of p53. MiR‑138‑5p decreases the enzyme activity of SIRT1 by specifically targeting its 3'‑UTR and activates p53 signaling, followed by triggering cardiomyocyte apoptosis during the process of HF. It is considered that miR‑138‑5p and SIRT1 may be potential diagnostic biomarkers and therapeutic targets for HF.

Keywords: microRNA‑138‑5p; sirtuin 1; p53; acetylation; heart failure.

Figure 1.

A negative correlation between SIRT1 and miR-138-5p in cardiomyocytes. (A) The relative mRNA level of SIRT1 and miR-138-5p. (B) Negative correlation between SIRT1 and miR-138-5p. (C) The relative level of SIRT1. SIRT1, sirtuin 1; miR, microRNA. *P<0.05 vs. AC-16.

Figure 2.

miR-138-5p targets SIRT1. (A) The binding sites in the 3′-UTR of miR-138-5p and SIRT1 were predicted using TargetScan. (B) The direct binding between miR-138-5p and SIRT1 was analyzed by the dual-luciferase reporter assay. ***P<0.001. miR, microRNA; UTR, untranslated region; SIRT1, sirtuin 1; NS, not significant.

Figure 3.

miR-138-5p inhibits the expression level and enzyme activity of SIRT1. (A) The efficacy of miR-138-5p mimic and inhibitor. (B) The relative mRNA expression of SIRT1. (C) The protein expression of SIRT1. (D) The enzyme activity of SIRT1 in AC-16 and HCM cells transfected with the miR-138-5p mimic, mimic NC, miR-138-5p inhibitor, or inhibitor NC, respectively. *P<0.05, ***P<0.001. miR, microRNA; SIRT1, sirtuin 1; NC, negative control; NS, not significant.

Figure 4.

miR-138-5p regulates the heart failure process via SIRT1-regulated p53 signaling. AC-16 and HCM were induced with H₂O₂ for 6 h. (A) Upregulated NPPB level. (B) Mean fluorescence intensity of reactive oxygen species. (C) Apoptosis proportion. (D) Relative mRNA levels of SIRT1, p53 and NPPB. (E) Protein levels of SIRT1, p53 and acetyl-p53. *P<0.05, **P<0.01, ***P<0.001. miR, microRNA; NC, negative control; SIRT1, sirtuin 1; H₂O₂, hydrogen peroxide; NPPB, natriuretic peptide precursor B; NS, not significant.

Figure 5.

Protective effect of SIRT1 in heart failure. (A) Relative SIRT1 mRNA expression of AC-16 and HCM cells overexpressing SIRT1. (B) Apoptosis in H₂O₂-induced AC-16 and HCM cells overexpressing SIRT1. (C) The relative mRNA expression of NPPB, SIRT1 and p53. (D) The protein expression of SIRT1, p53 and acetyl-p53 in H₂O₂-induced AC-16 and HCM cells overexpressing SIRT1. *P<0.05, **P<0.01, ***P<0.001. SIRT1, sirtuin 1; H₂O₂, hydrogen peroxide; NS, not significant.