Endothelial SIRT1 prevents adverse arterial remodeling by facilitating HERC2-mediated degradation of acetylated LKB1.
Aims-SIRT1 exerts potent activity against cellular senescence and vascular ageing. By decreasing LKB1 protein levels, it promotes the survival and regeneration of endothelial cells. The present study aims to investigate the molecular mechanisms underlying SIRT1-mediated LKB1 degradation for the prevention of vascular ageing.Methods and Results-Co-immunoprecipitation assay demonstrated that SIRT1, via its amino-terminus, binds to the DOC domain of HERC2 [HECT and RLD domain containing E3 ubiquitin protein ligase 2], which then ubiquitinates LKB1 in the nuclear compartment of endothelial cells. Site-directed mutagenesis revealed that acetylation at lysine (K) 64 of LKB1 triggers the formation of SIRT1/HERC2/LKB1 protein complex and subsequent proteasomal degradation. In vitro cellular studies suggested that accumulation of acetylated LKB1 in the nucleus leads to endothelial activation, in turn stimulating the proliferation of vascular smooth muscle cells and the production of extracellular matrix proteins. Chromatin immunoprecipitation quantitative PCR confirmed that acetylated LKB1 interacts with and activates TGFβ1 promoter, which is inhibited by SIRT1. Knocking down either SIRT1 or HERC2 results in an increased association of LKB1 with the positive regulatory elements of TGFβ1 promoter. In mice without endothelial nitric oxide synthase, selective overexpression of human SIRT1 in endothelium prevents hypertension and age-related adverse arterial remodeling. Lentiviral-mediated knockdown of HERC2 abolishes the beneficial effects of endothelial SIRT1 on both arterial remodeling and arterial blood pressure control.Conclusion-By downregulating acetylated LKB1 protein via HERC2, SIRT1 fine-tunes the crosstalk between endothelial and vascular smooth muscle cells to prevent adverse arterial remodeling and maintain vascular homeostasis.
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.|Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore.
Bo
B
Bai
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
Andy W C
AW
Man
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
Kangmin
K
Yang
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
Yumeng
Y
Guo
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
Cheng
C
Xu
Department of Medicine, The University of Hong Kong, Hong Kong, China.
Hung-Fat
HF
Tse
Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore.
Weiping
W
Han
Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
Maria
M
Bloksgaard
Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
Jo G R
JG
De Mey
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
Paul M
PM
Vanhoutte
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.|Department of Medicine, The University of Hong Kong, Hong Kong, China.
Aimin
A
Xu
State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
Yu
Y
Wang
D041721:3T3-L1 Cells; D000091162:AMP-Activated Protein Kinase Kinases; D000107:Acetylation; D000818:Animals; D001158:Arteries / Q000378:metabolism*; D002339:Carotid Arteries / Q000473:pathology; D045744:Cell Line, Tumor; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006706:Homeostasis; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D052250:Nitric Oxide Synthase Type III / Q000235:genetics; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D056564:Sirtuin 1 / Q000378:metabolism*; D025801:Ubiquitin / Q000737:chemistry; D044767:Ubiquitin-Protein Ligases; D066253:Vascular Remodeling
D020662:Guanine Nucleotide Exchange Factors; D025801:Ubiquitin; D052250:Nitric Oxide Synthase Type III; C118566:HERC2 protein, human; D044767:Ubiquitin-Protein Ligases; D017346:Protein Serine-Threonine Kinases; C109790:STK11 protein, human; D000091162:AMP-Activated Protein Kinase Kinases; C447939:SIRT1 protein, human; D056564:Sirtuin 1
Gerotarget; LKB1; SIRT1; blood vessel remodeling; endothelial senescence; hypertension