title: Homocysteine reduces protein S-nitrosylation in endothelium.
abstract: Hyperhomocysteinemia (HHcy) is a risk factor for cardiovascular disease. The S-nitrosylation of proteins is involved in the regulation of cardiovascular functions. However, whether homocysteine (Hcy) impairs vascular functions through the inhibition of protein S-nitrosylation in the endothelium remains to be determined. The experiments were performed in human umbilical vein endothelial cells (HUVECs). Male Sprague‑Dawley rats, with or without administration of L-methionine, were used for the in vivo validation of findings. S-nitrosylation was analyzed using immunofluorescence for nitrosocysteine, and further confirmed by the biotin switch method. The levels of reactive oxygen species (ROS) were detected by 2',7'-dichlorofluorescein diacetate (DCFH-DA) staining. The levels of nitric oxide (ΝΟ) were determined by the nitrate reduction method. Protein expression was analysed by western blot analysis. The activity of nuclear factor κB (NF-κB) was evaluated by an electrophoretic mobility shift assay (EMSA). The levels of plasma Hcy were measured by ELISA. The results showed that Hcy significantly reduced the levels of protein S-nitrosylation in HUVECs and endothelial S-nitrosylation of aorta. This reduction of protein S-nitrosylation was accompanied by increasing ROS, decreasing phosphorylation levels of Akt and endothelial nitric oxide synthase (eNOS), and reduced levels of nitric oxide in HUVECs. In addition, it was found that Hcy increased the protein expression of vascular cell adhesion molecule-1 by attenuating the cytoplasm S-nitrosylation of NF-κB (p65). These data suggested that Hcy impairs endothelial functions by inhibiting endothelial protein S-nitrosylation.
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Sihai
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Bai
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Ruihan
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898, Japan.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Fan
authors.affiliation: Research Institute of Atherosclerotic Disease, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Enqi
authors.initials: E
authors.lastname: Liu
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D006710:Homocysteine / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D020138:Hyperhomocysteinemia / Q000188:drug therapy; D008297:Male; D008715:Methionine / Q000008:administration & dosage; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017293:Protein S / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism
chemical_list: D017293:Protein S; D017382:Reactive Oxygen Species; D051996:Transcription Factor RelA; D019010:Vascular Cell Adhesion Molecule-1; D006710:Homocysteine; D009569:Nitric Oxide; D008715:Methionine; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat