{"title":"通过 CDK1 介导的有丝分裂调节,消融 Akt2 可挽救慢性热量限制诱发的心肌重塑和功能障碍","authors":"","doi":"10.1016/j.lfs.2024.123021","DOIUrl":null,"url":null,"abstract":"<div><p>Chronic caloric restriction triggers unfavorable alterations in cardiac function albeit responsible scenarios remain unclear. This work evaluated the possible involvement of Akt2 in caloric restriction-evoked cardiac geometric and functional changes and responsible processes focusing on autophagy and mitophagy. Akt2 knockout and WT mice were subjected to caloric restriction for 30 weeks prior to assessment of myocardial homeostasis. Caloric restriction compromised echocardiographic parameters (decreased LV wall thickness, LVEDD, stroke volume, cardiac output, ejection fraction, fractional shortening, and LV mass), cardiomyocyte contractile and intracellular Ca<sup>2+</sup> capacity, myocardial atrophy, interstitial fibrosis and mitochondrial injury associated with elevated blood glucocorticoids, autophagy (LC3B, p62, Atg7, Beclin-1), and mitophagy (Pink1, Parkin, TOM20), dampened cardiac ATP levels, mitochondrial protein PGC1α and UCP2, anti-apoptotic protein Bcl2, intracellular Ca<sup>2+</sup> governing components Na<sup>+</sup>-Ca<sup>2+</sup> exchanger, phosphorylation of SERCA2a, mTOR (Ser<sup>2481</sup>) and ULK1 (Ser<sup>757</sup>), and upregulated Bax, phospholamban, phosphorylation of Akt2, AMPK, and ULK1 (Ser<sup>555</sup>), the responses except autophagy markers (Beclin-1, Atg7), phosphorylation of AMPK, mTOR and ULK1 were negated by Akt2 ablation. Levels of CDK1 and DRP1 phosphorylation were overtly upregulated with caloric restriction, the response was reversed by Akt2 knockout. Caloric restriction-evoked changes in cardiac remodeling and cardiomyocyte function were alleviated by glucocorticoid receptor antagonism, Parkin ablation and Mdivi-1. <em>In vitro</em> experiment indicated that serum deprivation or glucocorticoids evoked GFP-LC3B accumulation and cardiomyocyte dysfunction, which was negated by inhibition of Akt2, CDK1 or DRP1, whereas mitophagy induction reversed Akt2 ablation-evoked cardioprotection. These observations favor a protective role of Akt2 ablation in sustained caloric restriction-evoked cardiac pathological changes <em>via</em> correction of glucocorticoid-induced mitophagy defect in a CDK1-DRP1-dependent manner.</p></div>","PeriodicalId":18122,"journal":{"name":"Life sciences","volume":null,"pages":null},"PeriodicalIF":5.2000,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Ablation of Akt2 rescues chronic caloric restriction-provoked myocardial remodeling and dysfunction through a CDK1-mediated regulation of mitophagy\",\"authors\":\"\",\"doi\":\"10.1016/j.lfs.2024.123021\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Chronic caloric restriction triggers unfavorable alterations in cardiac function albeit responsible scenarios remain unclear. This work evaluated the possible involvement of Akt2 in caloric restriction-evoked cardiac geometric and functional changes and responsible processes focusing on autophagy and mitophagy. Akt2 knockout and WT mice were subjected to caloric restriction for 30 weeks prior to assessment of myocardial homeostasis. Caloric restriction compromised echocardiographic parameters (decreased LV wall thickness, LVEDD, stroke volume, cardiac output, ejection fraction, fractional shortening, and LV mass), cardiomyocyte contractile and intracellular Ca<sup>2+</sup> capacity, myocardial atrophy, interstitial fibrosis and mitochondrial injury associated with elevated blood glucocorticoids, autophagy (LC3B, p62, Atg7, Beclin-1), and mitophagy (Pink1, Parkin, TOM20), dampened cardiac ATP levels, mitochondrial protein PGC1α and UCP2, anti-apoptotic protein Bcl2, intracellular Ca<sup>2+</sup> governing components Na<sup>+</sup>-Ca<sup>2+</sup> exchanger, phosphorylation of SERCA2a, mTOR (Ser<sup>2481</sup>) and ULK1 (Ser<sup>757</sup>), and upregulated Bax, phospholamban, phosphorylation of Akt2, AMPK, and ULK1 (Ser<sup>555</sup>), the responses except autophagy markers (Beclin-1, Atg7), phosphorylation of AMPK, mTOR and ULK1 were negated by Akt2 ablation. Levels of CDK1 and DRP1 phosphorylation were overtly upregulated with caloric restriction, the response was reversed by Akt2 knockout. Caloric restriction-evoked changes in cardiac remodeling and cardiomyocyte function were alleviated by glucocorticoid receptor antagonism, Parkin ablation and Mdivi-1. <em>In vitro</em> experiment indicated that serum deprivation or glucocorticoids evoked GFP-LC3B accumulation and cardiomyocyte dysfunction, which was negated by inhibition of Akt2, CDK1 or DRP1, whereas mitophagy induction reversed Akt2 ablation-evoked cardioprotection. These observations favor a protective role of Akt2 ablation in sustained caloric restriction-evoked cardiac pathological changes <em>via</em> correction of glucocorticoid-induced mitophagy defect in a CDK1-DRP1-dependent manner.</p></div>\",\"PeriodicalId\":18122,\"journal\":{\"name\":\"Life sciences\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.2000,\"publicationDate\":\"2024-08-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Life sciences\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0024320524006118\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MEDICINE, RESEARCH & EXPERIMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Life sciences","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0024320524006118","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
Ablation of Akt2 rescues chronic caloric restriction-provoked myocardial remodeling and dysfunction through a CDK1-mediated regulation of mitophagy
Chronic caloric restriction triggers unfavorable alterations in cardiac function albeit responsible scenarios remain unclear. This work evaluated the possible involvement of Akt2 in caloric restriction-evoked cardiac geometric and functional changes and responsible processes focusing on autophagy and mitophagy. Akt2 knockout and WT mice were subjected to caloric restriction for 30 weeks prior to assessment of myocardial homeostasis. Caloric restriction compromised echocardiographic parameters (decreased LV wall thickness, LVEDD, stroke volume, cardiac output, ejection fraction, fractional shortening, and LV mass), cardiomyocyte contractile and intracellular Ca2+ capacity, myocardial atrophy, interstitial fibrosis and mitochondrial injury associated with elevated blood glucocorticoids, autophagy (LC3B, p62, Atg7, Beclin-1), and mitophagy (Pink1, Parkin, TOM20), dampened cardiac ATP levels, mitochondrial protein PGC1α and UCP2, anti-apoptotic protein Bcl2, intracellular Ca2+ governing components Na+-Ca2+ exchanger, phosphorylation of SERCA2a, mTOR (Ser2481) and ULK1 (Ser757), and upregulated Bax, phospholamban, phosphorylation of Akt2, AMPK, and ULK1 (Ser555), the responses except autophagy markers (Beclin-1, Atg7), phosphorylation of AMPK, mTOR and ULK1 were negated by Akt2 ablation. Levels of CDK1 and DRP1 phosphorylation were overtly upregulated with caloric restriction, the response was reversed by Akt2 knockout. Caloric restriction-evoked changes in cardiac remodeling and cardiomyocyte function were alleviated by glucocorticoid receptor antagonism, Parkin ablation and Mdivi-1. In vitro experiment indicated that serum deprivation or glucocorticoids evoked GFP-LC3B accumulation and cardiomyocyte dysfunction, which was negated by inhibition of Akt2, CDK1 or DRP1, whereas mitophagy induction reversed Akt2 ablation-evoked cardioprotection. These observations favor a protective role of Akt2 ablation in sustained caloric restriction-evoked cardiac pathological changes via correction of glucocorticoid-induced mitophagy defect in a CDK1-DRP1-dependent manner.
期刊介绍:
Life Sciences is an international journal publishing articles that emphasize the molecular, cellular, and functional basis of therapy. The journal emphasizes the understanding of mechanism that is relevant to all aspects of human disease and translation to patients. All articles are rigorously reviewed.
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