title: Folic Acid Attenuates Vascular Endothelial Cell Injury Caused by Hypoxia via the Inhibition of ERK1/2/NOX4/ROS Pathway.
abstract: Coronary artery disease is a disease with high morbidity and mortality, in which vascular endothelial dysfunction plays an important role. Hypoxia leads to the inflammation and oxidative stress in endothelial cells, which results in the endothelial injury. The present study was designed to investigate the protective effect and mechanism of folic acid on hypoxia-induced injury in human umbilical vein endothelial cells (HUVEC). Cell counting Kit was used to detect cell survival rate, and apoptotic cells were detected by Hoechst 33258 staining. Intracellular reactive oxygen species (ROS) level was measured using dichloro-dihydro-fluorescein diacetate staining. Western blot was used to determine the protein expressions of extracellular signal protein kinase 1/2 (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2), NOX4 subunit of NAPDH and endothelial nitric oxide synthase (eNOS). Folic acid significantly increased the cell survival rate and decreased the apoptosis of HUVECs treated with folic acid compared with hypoxia-treated HUVEC. Folic acid also decreased ROS level, while it increased the nitrite content in HUVECs. In addition, folic acid decreased protein expressions of NOX4 and p-ERK1/2, while it increased the protein expression of eNOS in HUVECs. Furthermore, N-acetyl cysteine (NAC), the antioxidant, had similar effect on the cell survival rate and the apoptosis. In addition, DPI (NOX4 inhibitor) and U0126 (ERK1/2 inhibitor) rather than NAC decreased the protein expression of NOX4. NAC, DPI, and U0126 increased the protein expression of eNOS. Furthermore, U0126 rather than DPI and NAC decreased the protein expression of p-ERK1/2. Taken together, the results suggested that hypoxia decreased the cell survival rate and induced apoptosis via ERK1/2/NOX4/ROS pathway, which could be the target of folic acid in protecting the HUVECs from injury caused by hypoxia.
authors.affiliation: Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Cheng
authors.affiliation: Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lan
authors.affiliation: Department of Hypertension and Vascular Disease, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Wenhao
authors.initials: W
authors.lastname: Xia
authors.affiliation: Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Tu
authors.affiliation: Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China.
authors.forename: Benfa
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China.
authors.forename: Shicheng
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China. weibiaop@sina.com.
authors.forename: Weibiao
authors.initials: W
authors.lastname: Pan
mesh_terms: D003324:Coronary Artery Disease / Q000473:pathology; D019610:Cytoprotection / Q000187:drug effects*; D005492:Folic Acid / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D005492:Folic Acid; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; D048052:Mitogen-Activated Protein Kinase 3
keywords: Endothelial nitric oxide synthase; Extracellular signal protein kinase; Folic acid; Human umbilical vein endothelial cells; Hypoxia; Reactive oxygen species