Bing Yu1, Ziyi Liu1, Yi Fu1, Yingbao Wang1, Lu Zhang1, Zeyu Cai1, Fang Yu1, Xian Wang1, Jun Zhou2, Wei Kong2. 1. From the Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, P. R. China (B.Y., Z.L., Y.F., Y.W., L.Z., Z.C., F.Y., X.W., W.K.); Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, P. R. China (B.Y., Z.L., Y.F., Y.W., L.Z., Z.C., F.Y., X.W., W.K.); and State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, P. R. China (J.Z.). 2. From the Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, P. R. China (B.Y., Z.L., Y.F., Y.W., L.Z., Z.C., F.Y., X.W., W.K.); Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, P. R. China (B.Y., Z.L., Y.F., Y.W., L.Z., Z.C., F.Y., X.W., W.K.); and State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, P. R. China (J.Z.). kongw@bjmu.edu.cn Junzhou@nankai.edu.cn.
Abstract
OBJECTIVE: Transdifferentiation of adventitial fibroblasts (AFs) into myofibroblasts plays a critical role during the vascular remodeling that occurs during atherosclerosis, restenosis, and aortic aneurysm. The ubiquitination/deubiquitination regulatory system is essential for the quality control of proteins. The involvement of ubiquitination/deubiquitination during AF transdifferentiation remains largely unknown. In this study, we determined the role of cylindromatosis (CYLD), a deubiquitinase, in the process of AF differentiation and activation in vitro and in vivo. APPROACH AND RESULTS: Transforming growth factor-β1 and homocysteine, 2 known inducers of AF transdifferentiation, greatly upregulated CYLD expression in a time- and dose-dependent manner. The silencing of CYLD significantly inhibited AF transdifferentiation and activation as evidenced by the expression of contractile proteins, the production of the proinflammatory cytokines MCP-1 (monocyte chemotactic protein 1) and IL-6 (interleukin-6), the deposition of extracellular matrix, and cell migration. We further asked whether CYLD mediates AF activation via the regulation of nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) as it is an essential factor during AF transdifferentiation. Indeed, the silencing of CYLD repressed transforming growth factor-β1-induced and homocysteine-induced Nox4 upregulation and reactive oxygen species production, whereas Nox4 overexpression greatly rescued the inhibitory effect on AF activation by CYLD silencing. Most interestingly, transforming growth factor-β1 and homocysteine repressed Nox4 ubiquitination and prolonged the half-life of Nox4. Moreover, Nox4 was deubiquitinated via a direct interaction with the ubiquitin-specific protease domain of CYLD. In accordance, hyperhomocysteinemia significantly increased adventitial CYLD and Nox4 expression, promoted AF transdifferentiation, and aggravated CaPO4-induced abdominal aortic aneurysm in mice. These effects were abolished in CYLD-/- mice. CONCLUSIONS: CYLD contributes to the transdifferentiation of AFs via deubiquitinating Nox4 and may play a role in vascular remodeling.
OBJECTIVE: Transdifferentiation of adventitial fibroblasts (AFs) into myofibroblasts plays a critical role during the vascular remodeling that occurs during atherosclerosis, restenosis, and aortic aneurysm. The ubiquitination/deubiquitination regulatory system is essential for the quality control of proteins. The involvement of ubiquitination/deubiquitination during AF transdifferentiation remains largely unknown. In this study, we determined the role of cylindromatosis (CYLD), a deubiquitinase, in the process of AF differentiation and activation in vitro and in vivo. APPROACH AND RESULTS: Transforming growth factor-β1 and homocysteine, 2 known inducers of AF transdifferentiation, greatly upregulated CYLD expression in a time- and dose-dependent manner. The silencing of CYLD significantly inhibited AF transdifferentiation and activation as evidenced by the expression of contractile proteins, the production of the proinflammatory cytokines MCP-1 (monocyte chemotactic protein 1) and IL-6 (interleukin-6), the deposition of extracellular matrix, and cell migration. We further asked whether CYLD mediates AF activation via the regulation of nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) as it is an essential factor during AF transdifferentiation. Indeed, the silencing of CYLD repressed transforming growth factor-β1-induced and homocysteine-induced Nox4 upregulation and reactive oxygen species production, whereas Nox4 overexpression greatly rescued the inhibitory effect on AF activation by CYLD silencing. Most interestingly, transforming growth factor-β1 and homocysteine repressed Nox4 ubiquitination and prolonged the half-life of Nox4. Moreover, Nox4 was deubiquitinated via a direct interaction with the ubiquitin-specific protease domain of CYLD. In accordance, hyperhomocysteinemia significantly increased adventitial CYLD and Nox4 expression, promoted AF transdifferentiation, and aggravated CaPO4-induced abdominal aortic aneurysm in mice. These effects were abolished in CYLD-/- mice. CONCLUSIONS:CYLD contributes to the transdifferentiation of AFs via deubiquitinating Nox4 and may play a role in vascular remodeling.
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