title: Endoplasmic reticulum stress plays a role in the advanced glycation end product-induced inflammatory response in endothelial cells.
abstract: OBJECTIVE
  Both advanced glycation end products (AGEs) and endoplasmic reticulum (ER) stress play important roles in the development of various diseases. This study aimed to clarify the consequence of AGE-induced ER stress and its underlying mechanisms in human umbilical venous endothelial cells (HUVECs).
  
  
  METHODS
  AGE-induced ER stress was assessed by the increased expression and activation of the ER stress marker proteins GRP78, IRE1α and JNK, which were detected using Western blot. NF-κB translocation was revealed using Western blot and immunofluorescent staining in IRE1α-knockdown HUVECs. The mechanism of AGE-induced ER stress was also explored by inhibiting the effect of reactive oxygen species (ROS) using NADPH oxidase 4 (Nox4) siRNA and the antioxidant reduced glutathione (GSH). The cellular ROS level was measured using flow cytometry.
  
  
  RESULTS
  AGEs time- and dose-dependently enhanced the expression of GRP78 and increased the phosphorylation of IRE1α and its downstream signal JNK in HUVECs. siRNA-induced IRE1α down-regulation suppressed AGE-induced NF-κB p65 nuclear translocation. Inhibiting the ROS production using Nox4 siRNA or antagonizing ROS using GSH reduced cellular ROS level and attenuated AGE-induced GRP78 expression and IRE1α and JNK activation.
  
  
  CONCLUSIONS
  This study confirms that AGE-induced ER stress in HUVECs focuses on the ER stress-enhanced inflammatory response through JNK and NF-κB activation. It further reveals the involvement of ROS in the AGE-induced ER stress mechanism.
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Lili
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Da
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Liqun
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Pathophysiology, Key Lab for Shock and Microcirculation Research, Southern Medical University, Guangzhou 510515, P. R. China. Electronic address: bing@smu.edu.cn.
authors.forename: Qiaobing
authors.initials: Q
authors.lastname: Huang
mesh_terms: D015153:Blotting, Western; D015536:Down-Regulation; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000473:pathology*; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013997:Time Factors
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; D017127:Glycation End Products, Advanced; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D016328:NF-kappa B; D017382:Reactive Oxygen Species; C528229:ERN1 protein, human; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D004722:Endoribonucleases
keywords: Advanced glycation end products; Endoplasmic reticulum stress; Nuclear factor -κB; Reactive oxygen species; c-Jun N-terminal kinase