AMP-Activated Protein Kinase and Sirtuin 1 Coregulation of Cortactin Contributes to Endothelial Function

Tzu Pin Shentu, Ming He, Xiaoli Sun, Jianlin Zhang, Fan Zhang, Brendan Gongol, Traci L. Marin, Jiao Zhang, Liang Wen, Yinsheng Wang, Gregory G. Geary, Yi Zhu, David A. Johnson, John Y.J. Shyy

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

Objective - Cortactin translocates to the cell periphery in vascular endothelial cells (ECs) on cortical-actin assembly in response to pulsatile shear stress. Because cortactin has putative sites for AMP-activated protein kinase (AMPK) phosphorylation and sirtuin 1 (SIRT1) deacetylation, we examined the hypothesis that AMPK and SIRT1 coregulate cortactin dynamics in response to shear stress. Approach and Results - Analysis of the ability of AMPK to phosphorylate recombinant cortactin and oligopeptides whose sequences matched AMPK consensus sequences in cortactin pointed to Thr-401 as the site of AMPK phosphorylation. Mass spectrometry confirmed Thr-401 as the site of AMPK phosphorylation. Immunoblot analysis with AMPK siRNA and SIRT1 siRNA in human umbilical vein ECs and EC-specific AMPKα2 knockout mice showed that AMPK phosphorylation of cortactin primes SIRT1 deacetylation in response to shear stress. Immunoblot analyses with cortactin siRNA in human umbilical vein ECs, phospho-deficient T401A and phospho-mimetic T401D mutant, or aceto-deficient (9K/R) and aceto-mimetic (9K/Q) showed that cortactin regulates endothelial nitric oxide synthase activity. Confocal imaging and sucrose-density gradient analyses revealed that the phosphorylated/deacetylated cortactin translocates to the EC periphery facilitating endothelial nitric oxide synthase translocation from lipid to nonlipid raft domains. Knockdown of cortactin in vitro or genetic reduction of cortactin expression in vivo in mice substantially decreased the endothelial nitric oxide synthase-derived NO bioavailability. In vivo, atherosclerotic lesions increase in ApoE-/-/cortactin+/- mice, when compared with ApoE-/-/cortactin+/+ littermates. Conclusions - AMPK phosphorylation of cortactin followed by SIRT1 deacetylation modulates the interaction of cortactin and cortical-actin in response to shear stress. Functionally, this AMPK/SIRT1 coregulated cortactin-F-actin dynamics is required for endothelial nitric oxide synthase subcellular translocation/activation and is atheroprotective.

Original languageEnglish (US)
Pages (from-to)2358-2368
Number of pages11
JournalArteriosclerosis, Thrombosis, and Vascular Biology
Volume36
Issue number12
DOIs
StatePublished - Dec 1 2016
Externally publishedYes

Keywords

  • AMP-activated protein kinases
  • atherosclerosis
  • caveolin-1
  • cortactin
  • nitric oxide synthase type III

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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