MicroRNA-17-3p protects against excessive posthypoxic autophagy in H9C2 cardiomyocytes via PTEN-Akt-mTOR signaling pathway.

Autor: He Y; Department of Anesthesiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China., Zhang D; Department of Anesthesiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China., Zhang Q; Guangdong Provincial People's Hospital Ganzhou Hospital, Ganzhou Municipal Hospital, Ganzhou, China., Cai Y; Department of Anesthesiology, The University of Hong Kong, Hong Kong SAR, China., Huang C; Guangdong Provincial People's Hospital Ganzhou Hospital, Ganzhou Municipal Hospital, Ganzhou, China., Xia Z; Department of Anesthesiology, The University of Hong Kong, Hong Kong SAR, China.; Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Guangdong, China., Wang S; Department of Anesthesiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
Jazyk: angličtina
Zdroj: Cell biology international [Cell Biol Int] 2023 May; Vol. 47 (5), pp. 943-953. Date of Electronic Publication: 2023 Mar 19.
DOI: 10.1002/cbin.11999
Abstrakt: The activity of phosphatase and tensin homolog (PTEN) can be inhibited by miR-17-3p, which results in attenuating myocardial ischemia/reperfusion injury (IRI), however, the mechanism behind this phenomenon is still elusive. Suppression of PTEN leads to augmented protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling strength and constrained autophagy activation, which might be the one mechanism for the ameliorated myocardial IRI. Thus, we tested the hypothesis that miR-17-3p attenuated hypoxia/reoxygenation (H/R)-mediated damage in cardiomyocytes by downregulating excessive autophagy via the PTEN-Akt-mTOR axis. The expression of miR-17-3p was remarkably increased after H/R treatment (6-h hypoxia followed by 6-h reoxygenation; H6/R6), which was concomitant with the increase of the release of lactic acid dehydrogenase (cell injury marker) and the enhancement LC3II/I ratio (autophagy markers) in H9C2 cardiomyocytes. Ectoexpression of miR-17-3p agomir led to remarkable augmentation of miR-17-3p expression and evidently attenuated H/R-mediated cell damage and excessive autophagy. Furthermore, an increase in miR-17-3p expression elicited constrained phosphorylation of PTEN (Ser 380 ) while enhanced the phosphorylation of Akt (Thr 308 , Ser 473 ) and mTOR (Ser 536 ) after H/R stimulation. In addition, pretreatment with LY-294002 (an Akt selective inhibitor) and rapamycin (an mTOR selective inhibitor) significantly abrogated the protective function of miR-17-3p on H/R-mediated cell damage and autophagy in H9C2 cardiomyocytes. Taken together, these observations indicated that the enhancement of the PTEN/Akt/mTOR axis and the consequent suppression of autophagy overactivation might represent an underlying mechanism by which miR-17-3p attenuated H/R-mediated damage in H9C2 cells.
(© 2023 International Federation for Cell Biology.)
Databáze: MEDLINE
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