Sirtuin 1 represses PKC-? activity through regulating interplay of acetylation and phosphorylation in cardiac hypertrophy.
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ABSTRACT: BACKGROUND AND PURPOSE:Activation of PKC-? is closely linked to the pathogenesis of cardiac hypertrophy. PKC-? can be activated by certain lipid metabolites such as phosphatidylinositol (3,4,5)-trisphosphate and ceramide. However, its endogenous negative regulators are not well defined. Here, the role of the sirtuin1-PKC-? signalling axis and the underlying molecular mechanisms were investigated in cardiac hypertrophy. EXPERIMENTAL APPROACH:Cellular hypertrophy in cultures of cardiac myocytes, from neonatal Sprague-Dawley rats, was monitored by measuring cell surface area and the mRNA levels of hypertrophic biomarkers. Interaction between sirtuin1 and PKC-? was investigated by co-immunoprecipitation and confocal immunofluorescence microscopy. Sirtuin1 activation was enhanced by resveratrol treatment or Ad-sirtuin1 transfection. A model of cardiac hypertrophy in Sprague-Dawley rats was established by abdominal aortic constriction surgery or induced by isoprenaline in vivo. KEY RESULTS:Overexpression of PKC-? led to cardiac hypertrophy and increased activity of NF-?B, ERK1/2 and ERK5, which was ameliorated by sirtuin1 overexpression. Enhancement of sirtuin1 activity suppressed acetylation of PKC-?, hindered its binding to phosphoinositide-dependent kinase 1 and inhibited PKC-? phosphorylation in cardiac hypertrophy. Consequently, the downstream pathways of PKC-?' were suppressed in cardiac hypertrophy. This regulation loop suggests a new role for sirtuin1 in mediation of cardiac hypertrophy. CONCLUSIONS AND IMPLICATIONS:Sirtuin1 is an endogenous negative regulator for PKC-? and mediates its activity via regulating the acetylation and phosphorylation in the pathogenesis of cardiac hypertrophy. Targeting the sirtuin1-PKC-? signalling axis may suggest a novel therapeutic approach against cardiac hypertrophy.
SUBMITTER: Li J
PROVIDER: S-EPMC6329629 | biostudies-literature | 2019 Feb
REPOSITORIES: biostudies-literature
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