MiR‐199a‐5p promotes ferroptosis‐induced cardiomyocyte death responding to oxygen–glucose deprivation/reperfusion injury via inhibiting Akt/eNOSsignaling pathway

Abstract

Myocardial ischemia/reperfusion (I/R) injury is associated with the poor outcome and higher mortality after myocardial infarction. Recent studies have revealed that miR‐199a‐5p participates in the process of myocardial I/R injury, but the precise roles and molecular mechanisms of miR‐199a‐5p in myocardial I/R injury remain not well‐studied. Ferroptosis has been proposed to promote cardiomyocyte death, closely associated with myocardial I/R injury. Herein, the present study aimed to explore the function and mechanisms by which miR‐199a‐5p regulates whether miR‐199a‐5p contributes to ferroptosis‐induced cardiomyocyte death responding to oxygen–glucose deprivation/reoxygenation (OGD/R) injury, an in vitro model of myocardial I/R injury focusing on Akt/eNOS signaling pathway. The results found that ferroptosis‐induced cardiomyocyte death occurs and is accompanied by an increase in miR‐199a‐5p level in OGD/R‐treated H9c2 cells. MiR‐199a‐5p inhibitor ameliorated ferroptosis‐induced cardiomyocyte death as evidenced by the increased cell viability, the reduced reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) and Fe2+ contents, and the up‐regulated glutathione (GSH)/glutathione disulphide (GSSG) ratio as well as glutathione peroxidase 4 (Gpx4) protein expression in H9c2 cells‐exposed to OGD/R, while miR‐199a‐5p mimic had the opposite effects. In addition, OGD/R led to the inhibition of Akt/eNOS signaling pathway, which was also blocked by miR‐199a‐5p inhibitor and aggravated by miR‐199a‐5p mimic. Furthermore, LY294002, an inhibitor of Akt/eNOS signaling pathway, abrogated miR‐199a‐5p inhibitor‐induced the reduction of ferroptosis‐induced cardiomyocyte death. In summary, our findings demonstrated that miR‐199a‐5p plays a central role in stimulating ferroptosis‐induced cardiomyocyte death during ischemic/hypoxic injury via inhibiting Akt/eNOS signaling pathway.

Ferroptosis, a Regulated Form of Cell Death, as a Target for the Development of Novel Drugs Preventing Ischemia/Reperfusion of Cardiac Injury, Cardiomyopathy and Stress-Induced Cardiac Injury

“…NOS. We have already reported above that the miR-199a-5p inhibitor suppressed ferroptosis and increased H9c2 cell survival in H/R through the activation of Akt [49]. It Akt.…”

“…The miR-199a-5p inhibitor increased cell viability, suppressed ferroptosis, and increased the p-Akt/Akt ratio [49]. The Akt inhibitor LY294002 abolished the cytoprotective effect of the miR-199a-5p inhibitor and reduced the p-Akt/Akt ratio [49]. Consequently, the activation of Akt promotes the inhibition of ferroptosis and an increase in cell viability in H/R.…”

“…H9c2 cells were transfected with a microRNA miR-199a-5p inhibitor to down-regulate miR-199a-5p and an miR-199a-5p mimic to up-regulate miR-199a-5p prior to H/R. The miR-199a-5p inhibitor increased cell viability, suppressed ferroptosis, and increased the p-Akt/Akt ratio [49]. The Akt inhibitor LY294002 abolished the cytoprotective effect of the miR-199a-5p inhibitor and reduced the p-Akt/Akt ratio [49].…”

Targeting epigenetic and posttranslational modifications regulating ferroptosis for the treatment of diseases

“… 399 MIRI ncRNA GPX4 MiR-199a-5p promotes cardiomyocyte death in OGD/R-treated H9c2 cells through inducing ferroptosis via downregulation of GPX4 by inhibiting Akt/eNOS signaling pathway. 400 MIRI ncRNA ME2 Upregulated miR-214-3p promotes MIRI through inducing ferroptosis via suppressing ME2. 401 MIRI ncRNA GPX4 Egr-1-mediated upregulation of miR-15a-5p promotes MIRI through inducing ferroptosis via suppressing GPX4.…”

AEBP1 exacerbates myocardial ischemia-reperfusion injury via inhibition of IκBα

“…RT-qPCR was performed as described before [17]. In brief, total RNA was extracted from H9c2 cells using the TRIzol reagent (Thermo Fisher), and subsequently transcribed into cDNA using the Transcriptor First Strand cDNA Synthesis Kit (Thermo Fisher).…”