Hypochlorite-Modified Albumin Upregulates ICAM-1 Expression via a MAPK-NF-κB Signaling Cascade: Protective Effects of Apocynin

Oxid Med Cell Longev. 2016:2016:1852340. doi: 10.1155/2016/1852340. Epub 2016 Jan 10.

Abstract

Hypochlorite-modified albumin (HOCl-alb) has been linked to endothelial dysfunction, which plays an important role in the development of hypertension, diabetes, and chronic kidney disease. However, whether HOCl-alb induces endothelial dysfunction via vascular inflammation and whether a signaling pathway is involved are unknown and have not been investigated. HOCl-alb was found to upregulate ICAM-1 expression in human umbilical vein endothelial cells (HUVECs) in a time- and dose-dependent manner. HOCl-alb time-dependently phosphorylated ERK1/2 and p38(MAPK). HOCl-alb also activated NF-κB. ICAM-1 expression was dose-dependently inhibited by U0126 (a specific inhibitor of MEK1/2, a signal upstream from ERK1/2), SB203580 (a specific inhibitor of p38(MAPK)), and SN50 (a specific inhibitor of NF-κB). U0126 and SB203580 both counteracted the activation of NF-κB, whereas the phosphorylation of ERK1/2 and p38(MAPK) was not blocked by SN50. ERK1/2 phosphorylation was blocked by U0126 but not by SB203580, and p38(MAPK) activity was reduced by SB203580 but not by U0126. Apocynin, a specific NADPH oxidase (NOX) inhibitor, inhibited ICAM-1 expression and the activity of ERK1/2, p38(MAPK), and NF-κB. These results indicate that HOCl-alb-induced ICAM-1 expression is caused by the activation of a redox-sensitive intracellular signal cascade involving ERK1/2 and p38(MAPK), culminating in the activation of NF-κB and involving NOXs among the upstream signals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetophenones / chemistry*
  • Albumins / chemistry*
  • Endothelial Cells / cytology
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Hypochlorous Acid / chemistry*
  • Intercellular Adhesion Molecule-1 / metabolism*
  • MAP Kinase Signaling System*
  • Microscopy, Fluorescence
  • NF-kappa B / metabolism*
  • Oxidative Stress
  • Phosphorylation
  • Signal Transduction
  • Up-Regulation
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Acetophenones
  • Albumins
  • ICAM1 protein, human
  • NF-kappa B
  • Intercellular Adhesion Molecule-1
  • Hypochlorous Acid
  • acetovanillone
  • Extracellular Signal-Regulated MAP Kinases
  • p38 Mitogen-Activated Protein Kinases