LPS-induced neutrophilic inflammation and Bcl-2 expression in metaplastic mucous cells

Am J Physiol Lung Cell Mol Physiol. 2003 Aug;285(2):L405-14. doi: 10.1152/ajplung.00249.2002. Epub 2003 Apr 18.

Abstract

Our previous studies show that Bcl-2, a regulator of apoptosis, may be involved in the reduction of mucous cell metaplasia (MCM) during recovery from inflammatory responses. The present study was to determine whether neutrophilic inflammation mediates Bcl-2 expression in mucous cells. Rats were intratracheally instilled with 50-1000 microg of LPS. The number of neutrophils recovered by bronchoalveolar lavage (BAL) increased with the dose of LPS, and the percentage of Bcl-2-expressing cells increased with the numbers of neutrophils in the BAL. Depletion of neutrophils did not reduce MCM, but the percentage of Bcl-2-positive cells increased 1.8-fold in neutrophil-depleted compared with controls. Injection of rats with bezafibrate, an inducer of cytochrome P-450, doubled the number of neutrophils in the BAL, decreased MCM twofold compared with vehicle-injected controls, and reduced Bcl-2 expression. Bcl-2 mRNA levels decreased in a tracheal epithelial cell line treated with bezafibrate. These data demonstrate that Bcl-2 expression is independent of the number of neutrophils in the BAL and that bezafibrate may directly reduce Bcl-2 expression in epithelial cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bezafibrate / pharmacology
  • Bronchoalveolar Lavage Fluid / cytology
  • DNA Primers
  • Dose-Response Relationship, Drug
  • Genes, bcl-2 / drug effects
  • Hypolipidemic Agents / pharmacology
  • Inflammation / genetics
  • Inflammation / pathology*
  • Lipopolysaccharides / toxicity*
  • Macrophages, Alveolar / drug effects
  • Macrophages, Alveolar / physiology
  • Male
  • Metaplasia
  • Neutrophils / drug effects
  • Neutrophils / physiology*
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins c-bcl-2 / genetics*
  • Rats
  • Rats, Inbred BN
  • Rats, Inbred F344
  • Time Factors
  • Transcription, Genetic / drug effects

Substances

  • DNA Primers
  • Hypolipidemic Agents
  • Lipopolysaccharides
  • Proto-Oncogene Proteins c-bcl-2
  • Bezafibrate