title: Angiotensin II induced proteolytic cleavage of myocardial ACE2 is mediated by TACE/ADAM-17: a positive feedback mechanism in the RAS.
abstract: Angiotensin converting enzyme (ACE) 2 is a key negative regulator of the renin-angiotensin system where it metabolizes angiotensin (Ang) II into Ang 1-7. We hypothesize that Ang II suppresses ACE2 by increasing TNF-α converting enzyme (TACE) activity and ACE2 cleavage. Ang II infusion (1.5 mg/kg/day) in wild-type mice for 2 weeks resulted in substantial decrease in myocardial ACE2 protein levels and activity with corresponding increase in plasma ACE2 activity, prevented by AT1R blockade. Ang II resulted in AT1R-mediated increase in myocardial TACE expression and activity, and membrane translocation of TACE. Ang II treatment in Huh7 cells exhibited AT1R-dependent metalloproteinase mediated shedding of ACE2 while transfection with siTACE prevented shedding of ACE2; cardiomyocyte-specific deletion of TACE also prevented shedding of ACE2. Reactive oxygen species played a key role since p47(phox)KO mice were resistant to Ang II-induced TACE phosphorylation and activation with preservation of myocardial ACE2 which dampened Ang II-induced cardiac dysfunction and hypertrophy. In conclusion, Ang II induces ACE2 shedding by promoting TACE activity as a positive feedback mechanism whereby Ang II facilitates the loss of its negative regulator, ACE2. In HF, elevated plasma ACE2 activity likely represents loss of the protective effects of ACE2 in the heart.
authors: Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
authors: Vaibhav B
authors: VB
authors: Patel
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
authors: Nicola
authors: N
authors: Clarke
authors: Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
authors: Zuocheng
authors: Z
authors: Wang
authors: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Department of Physiology, University of Alberta, Edmonton, Canada.
authors: Dong
authors: D
authors: Fan
authors: Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
authors: Nirmal
authors: N
authors: Parajuli
authors: Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
authors: Ratnadeep
authors: R
authors: Basu
authors: Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
authors: Brendan
authors: B
authors: Putko
authors: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada; Department of Physiology, University of Alberta, Edmonton, Canada.
authors: Zamaneh
authors: Z
authors: Kassiri
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
authors: Anthony J
authors: AJ
authors: Turner
authors: Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada. Electronic address: gavin.oudit@ualberta.ca.
authors: Gavin Y
authors: GY
authors: Oudit
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000072198:ADAM17 Protein; D000804:Angiotensin II / Q000494:pharmacology*; D000085962:Angiotensin-Converting Enzyme 2; D000818:Animals; D002460:Cell Line; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D059748:Proteolysis; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics / Q000378:metabolism*; D012084:Renin-Angiotensin System / Q000502:physiology; D015398:Signal Transduction
chemical_list: D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D007703:Peptidyl-Dipeptidase A; C000705307:ACE2 protein, human; C000705328:Ace2 protein, mouse; D000085962:Angiotensin-Converting Enzyme 2; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; C000606463:Adam17 protein, mouse
keywords: ACE; AT1R; Ang; Angiotensin II; Angiotensin converting enzyme 2; HF; KO; RAS; ROS; Renin–angiotensin system; TACE; TNF-α converting enzyme; angiotensin; angiotensin II type 1 receptor; angiotensin converting enzyme; heart failure; knockout; p38 MAPK; p38 mitogen activated protein kinase; reactive oxygen species; renin–angiotensin system; tumor necrosis factor-α converting enzyme