title: The role of endoplasmic reticulum stress in endothelial dysfunction induced by homocysteine thiolactone.
abstract: Our and other studies have reported that homocysteine thiolactone (HTL) could induce endothelial dysfunction. However, the precise mechanism was largely unknown. In this study, we tested the most possible factor-endoplasmic reticulum (ER) stress, which was demonstrated to be involved in endothelial dysfunction in cardiovascular disease. Acetylcholine (Ach)-induced endothelium-dependent relaxation (EDR) and biochemical parameters were measured in rat isolated aorta. The level of reactive oxygen species (ROS) and NO was designed by specific fluorescent probe DCFH-DA and DAF-FM DA separately. The nuclear translocation of the NF-κB was studied by immune-fluorescence. The mRNA expression and protein expression of GRP78--a key indicator for the induction of ER stress--were assessed by real-time PCR and Western blot. Two ER stress inhibitors-4-PBA (5 mm) and Tudca (500 μg/mL)--significantly prevented HTL-impaired EDR and increased NO release, endothelial nitric oxide synthase (eNOS) and SOD activity, decreased ROS production, NADPH activity, NOX-4 mRNA and MDA level. We also found that 4-PBA and Tudca blocked HTL--induced NF-κB activation thus inhibiting the downstream target gene production including TNF-α and ICAM-1. Simultaneously, HTL increased the mRNA and protein level of GRP78. HTL could induce ER stress leading to a downstream enhancement of oxidative stress and inflammation, which finally caused vascular endothelial dysfunction.
authors.affiliation: Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China.
authors.forename: Shujin
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China.
authors.forename: Shehua
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China.
authors.forename: Min
authors.initials: M
authors.lastname: Meng
authors.affiliation: Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China.
authors.forename: Xiaolai
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Pharmacy, Gan Su Provincial Hospital, Lan Zhou, 73000, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Ge
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006710:Homocysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D018836:Inflammation Mediators; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D014665:Vasodilator Agents; D006710:Homocysteine; D009569:Nitric Oxide; C007957:homocysteine thiolactone; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III
keywords: NF-κB; endoplasmic reticulum stress; endothelial dysfunction; homocysteine thiolactone; oxidative stress