Paula Reventun1, Matilde Alique1, Irene Cuadrado1, Susana Márquez1, Rocío Toro1, Carlos Zaragoza1, Marta Saura2. 1. From the Biology Systems Department, Physiology, School of Medicine and Health Sciences, Universidad Alcalá (IRYCIS), Madrid, Spain (P.R., M.A., S.M., M.S.); Cardiology Department, University Francisco de Vitoria/Hospital Ramón y Cajal Research Unit (IRYCIS), Madrid, Spain (C.Z.); and Cardiology Department, School of Medicine, Cádiz University, Spain (R.T.). 2. From the Biology Systems Department, Physiology, School of Medicine and Health Sciences, Universidad Alcalá (IRYCIS), Madrid, Spain (P.R., M.A., S.M., M.S.); Cardiology Department, University Francisco de Vitoria/Hospital Ramón y Cajal Research Unit (IRYCIS), Madrid, Spain (C.Z.); and Cardiology Department, School of Medicine, Cádiz University, Spain (R.T.). marta.saura@uah.es.
Abstract
OBJECTIVE: ILK (integrin-linked kinase) plays a key role in controlling vasomotor tone and is decreased in atherosclerosis. The objective of this study is to test whether nitric oxide (NO) regulates ILK in vascular remodeling. APPROACH AND RESULTS: We found a striking correlation between increased levels of inducible nitric oxide and decreased ILK levels in human atherosclerosis and in a mouse model of vascular remodeling (carotid artery ligation) comparing with iNOS (inducible NO synthase) knockout mice. iNOS induction produced the same result in mouse aortic endothelial cells, and these effects were mimicked by an NO donor in a time-dependent manner. We found that NO decreased ILK protein stability by promoting the dissociation of the complex ILK/Hsp90 (heat shock protein 90)/eNOS (endothelial NO synthase), leading to eNOS uncoupling. NO also destabilized ILK signaling platform and lead to decreased levels of paxillin and α-parvin. ILK phosphorylation of its downstream target GSK3-β (glycogen synthase kinase 3 beta) was decreased by NO. Mechanistically, NO increased ILK ubiquitination mediated by the E3 ubiquitin ligase CHIP (C terminus of HSC70-interacting protein), but ILK ubiquitination was not followed by proteasome degradation. Alternatively, NO drove ILK to degradation through the endocytic-lysosomal pathway. ILK colocalized with the lysosome marker LAMP-1 (lysosomal-associated membrane protein 1) in endothelial cells, and inhibition of lysosome activity with chloroquine reversed the effect of NO. Likewise, ILK colocalized with the early endosome marker EEA1 (early endosome antigen 1). ILK endocytosis proceeded via dynamin because a specific inhibitor of dynamin (Dyngo 4a) was able to reverse ILK endocytosis and its lysosome degradation. CONCLUSIONS: Endocytosis regulates ILK signaling in vascular remodeling where there is an overload of inducible NO, and thus its inhibition may represent a novel target to fight atherosclerotic disease.
OBJECTIVE:ILK (integrin-linked kinase) plays a key role in controlling vasomotor tone and is decreased in atherosclerosis. The objective of this study is to test whether nitric oxide (NO) regulates ILK in vascular remodeling. APPROACH AND RESULTS: We found a striking correlation between increased levels of inducible nitric oxide and decreased ILK levels in humanatherosclerosis and in a mouse model of vascular remodeling (carotid artery ligation) comparing with iNOS (inducible NO synthase) knockout mice. iNOS induction produced the same result in mouse aortic endothelial cells, and these effects were mimicked by an NO donor in a time-dependent manner. We found that NO decreased ILK protein stability by promoting the dissociation of the complex ILK/Hsp90 (heat shock protein 90)/eNOS (endothelial NO synthase), leading to eNOS uncoupling. NO also destabilized ILK signaling platform and lead to decreased levels of paxillin and α-parvin. ILK phosphorylation of its downstream target GSK3-β (glycogen synthase kinase 3 beta) was decreased by NO. Mechanistically, NO increased ILK ubiquitination mediated by the E3 ubiquitin ligase CHIP (C terminus of HSC70-interacting protein), but ILK ubiquitination was not followed by proteasome degradation. Alternatively, NO drove ILK to degradation through the endocytic-lysosomal pathway. ILK colocalized with the lysosome marker LAMP-1 (lysosomal-associated membrane protein 1) in endothelial cells, and inhibition of lysosome activity with chloroquine reversed the effect of NO. Likewise, ILK colocalized with the early endosome marker EEA1 (early endosome antigen 1). ILK endocytosis proceeded via dynamin because a specific inhibitor of dynamin (Dyngo 4a) was able to reverse ILK endocytosis and its lysosome degradation. CONCLUSIONS: Endocytosis regulates ILK signaling in vascular remodeling where there is an overload of inducible NO, and thus its inhibition may represent a novel target to fight atherosclerotic disease.
Authors: Hong S Lu; Ann Marie Schmidt; Robert A Hegele; Nigel Mackman; Daniel J Rader; Christian Weber; Alan Daugherty Journal: Arterioscler Thromb Vasc Biol Date: 2018-10 Impact factor: 8.311
Authors: Nicole R Gould; Katrina M Williams; Humberto C Joca; Olivia M Torre; James S Lyons; Jenna M Leser; Manasa P Srikanth; Marcus Hughes; Ramzi J Khairallah; Ricardo A Feldman; Christopher W Ward; Joseph P Stains Journal: Elife Date: 2021-03-29 Impact factor: 8.140