Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA. Academic Article uri icon

Overview

MeSH

  • Adult
  • Aged
  • Apoptosis
  • Cells, Cultured
  • Female
  • Humans
  • Male
  • Middle Aged
  • Phenotype

MeSH Major

  • Caveolin 1
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Gene Silencing
  • Macrophages, Alveolar
  • RNA, Messenger

abstract

  • The inflammatory milieu in the respiratory tract in cystic fibrosis (CF) has been linked to the defective expression of the cystic transmembrane regulator (CFTR) in epithelial cells. Alveolar macrophages (AM), important contibutors to inflammatory responses in the lung, also express CFTR. The present study analyzes the phenotype of human AM with silenced CFTR. Expression of CFTR mRNA and the immature form of the CFTR protein decreased 100-fold and 5.2-fold, respectively, in AM transfected with a CFTR specific siRNA (CFTR-siRNA) compared to controls. Reduction of CFTR expression in AM resulted in increased secretion of IL-8, increased phosphorylation of NF-kappaB, a positive regulator of IL-8 expression, and decreased expression of IkappaB-alpha, the inhibitory protein of NF-kappaB activation. AM with silenced CFTR expression also showed increased apoptosis. We hypothesized that caveolin-1 (Cav1), a membrane protein that is co-localized with CFTR in lipid rafts and that is related to inflammation and apoptosis in macrophages, may be affected by decreased CFTR expression. Messenger RNA and protein levels of Cav1 were increased in AM with silenced CFTR. Expression and transcriptional activity of sterol regulatory element binding protein (SREBP), a negative transcriptional regulator of Cav1, was decreased in AM with silenced CFTR, but total and free cholesterol mass did not change. These findings indicate that silencing of CFTR in human AM results in an inflammatory phenotype and apoptosis, which is associated to SREBP-mediated regulation of Cav1.

publication date

  • June 8, 2010

has subject area

  • Adult
  • Aged
  • Apoptosis
  • Caveolin 1
  • Cells, Cultured
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Female
  • Gene Silencing
  • Humans
  • Macrophages, Alveolar
  • Male
  • Middle Aged
  • Phenotype
  • RNA, Messenger

Research

keywords

  • Journal Article

Identity

Language

  • eng

PubMed Central ID

  • PMC2882373

Digital Object Identifier (DOI)

  • 10.1371/journal.pone.0011004

PubMed ID

  • 20543983

Additional Document Info

start page

  • e11004

volume

  • 5

number

  • 6