Malondialdehyde-acetaldehyde adducts decrease bronchial epithelial wound repair

Alcohol. 2005 May;36(1):31-40. doi: 10.1016/j.alcohol.2005.06.002.

Abstract

Most people who abuse alcohol are cigarette smokers. Previously, we have shown that malondialdehyde, an inflammation product of lipid peroxidation, and acetaldehyde, a component of both ethanol metabolism and cigarette smoke, form protein adducts that stimulate protein kinase C (PKC) activation in bronchial epithelial cells. We have also shown that PKC can regulate bronchial epithelial cell wound repair. We hypothesize that bovine serum albumin adducted with malondialdehyde and acetaldehyde (BSA-MAA) decreases bronchial epithelial cell wound repair via binding to scavenger receptors on bronchial epithelial cells. To test this, confluent monolayers of bovine bronchial epithelial cells were grown in serum-free media prior to wounding the cells. Bronchial epithelial cell wound closure was inhibited in a dose-dependent manner (up to 60%) in the presence of BSA-MAA than in media treated cells (Laboratory of Human Carcinogenesis [LHC]-9-Roswell Park Memorial Institute [RPMI]). The specific scavenger receptor ligand, fucoidan, also stimulated PKC activation and decreased wound repair. Pretreatment with fucoidan blocked malondialdehyde-acetaldehyde binding to bronchial epithelial cells. When bronchial epithelial cells were preincubated with a PKC alpha inhibitor, Gö 6976, the inhibition of wound closure by fucoidan and BSA-MAA was blocked. Western blot demonstrated the presence of several scavenger receptors on bronchial epithelial cell membranes, including SRA, SRBI, SRBII, and CD36. Scavenger receptor-mediated activation of PKC alpha may function to reduce wound healing under conditions of alcohol and cigarette smoke exposure where malondialdehyde-acetaldehyde adducts may be present.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetaldehyde / metabolism*
  • Animals
  • Bronchi / injuries*
  • Bronchi / physiology
  • Carbazoles / pharmacology
  • Cattle
  • Cell Line
  • Cyclic AMP-Dependent Protein Kinases / physiology
  • Epithelial Cells / physiology
  • Humans
  • Indoles / pharmacology
  • Malondialdehyde / metabolism*
  • Protein Binding
  • Protein Kinase C / physiology
  • Receptors, Scavenger / analysis
  • Receptors, Scavenger / physiology
  • Wound Healing*

Substances

  • Carbazoles
  • Indoles
  • Receptors, Scavenger
  • Go 6976
  • Malondialdehyde
  • Cyclic AMP-Dependent Protein Kinases
  • Protein Kinase C
  • Acetaldehyde