Increased aldehyde-modification of collagen type IV in symptomatic plaques--a possible cause of endothelial dysfunction

Atherosclerosis. 2015 May;240(1):26-32. doi: 10.1016/j.atherosclerosis.2015.02.043. Epub 2015 Feb 24.

Abstract

Objective: Subendothelial LDL-adhesion and its subsequent oxidation are considered as key events in the development of atherosclerotic lesions. During oxidation of LDL, reactive aldehydes such as malondialdehyde (MDA) are formed, which modify apolipoprotein B100. However, the possibility that these reactive aldehydes could leak out of the LDL-particle and modify surrounding extracellular matrix proteins has been largely unexplored. We have investigated if aldehyde-modification of collagen type IV, one of the major basement membrane components, in plaques is associated with cardiovascular events.

Methods: The amount of MDA-modified collagen type IV and native collagen type IV were determined in homogenates from 155 carotid artery lesions, removed by endarterectomy from patients with or without previous cerebrovascular events.

Results: Plaque MDA-collagen type IV, but not native collagen type IV, correlated with oxidized LDL (r=0.31, P<0.001) and lipoprotein-associated phospholipase A2 (r=0.44, P<0.001). MDA-collagen type IV was increased in lesions from symptomatic patients compared to lesions from asymptomatic patients. Auto-antibodies against MDA-collagen type IV in plasma correlated with the amount of MDA-collagen type IV in lesions. MDA-modification of collagen type IV decreased endothelial cell attachment. In addition, culture of endothelial cells with MDA-modified collagen type IV increased vascular cell adhesion molecule expression and reduced the anti-coagulant proteins thrombomodulin and endothelial protein C receptor. In the lesions native collagen type IV, but not MDA-collagen type IV, was positively associated with thrombomodulin.

Conclusion: The present observations imply that aldehyde-modification of collagen type IV, associated with LDL oxidation, in atherosclerotic plaques may cause endothelial dysfunction and increase the risk of clinical events.

Keywords: Aldehyde-modification; Collagen type IV; Endothelial dysfunction; LDL oxidation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Alkyl-2-acetylglycerophosphocholine Esterase / metabolism
  • Asymptomatic Diseases
  • Autoantibodies / metabolism
  • Carotid Arteries / immunology
  • Carotid Arteries / metabolism*
  • Carotid Arteries / pathology
  • Carotid Arteries / physiopathology
  • Carotid Artery Diseases / complications
  • Carotid Artery Diseases / diagnosis
  • Carotid Artery Diseases / immunology
  • Carotid Artery Diseases / metabolism*
  • Carotid Artery Diseases / physiopathology
  • Cell Adhesion
  • Cells, Cultured
  • Cerebrovascular Disorders / etiology
  • Collagen Type IV / immunology
  • Collagen Type IV / metabolism*
  • Endothelium, Vascular / immunology
  • Endothelium, Vascular / metabolism*
  • Endothelium, Vascular / pathology
  • Endothelium, Vascular / physiopathology
  • Humans
  • Lipoproteins, LDL / metabolism
  • Malondialdehyde / immunology
  • Malondialdehyde / metabolism*
  • Plaque, Atherosclerotic*
  • Protein Processing, Post-Translational
  • Thrombomodulin / metabolism
  • Vascular Cell Adhesion Molecule-1 / metabolism

Substances

  • Autoantibodies
  • Collagen Type IV
  • Lipoproteins, LDL
  • THBD protein, human
  • Thrombomodulin
  • Vascular Cell Adhesion Molecule-1
  • oxidized low density lipoprotein
  • Malondialdehyde
  • 1-Alkyl-2-acetylglycerophosphocholine Esterase
  • PLA2G7 protein, human