Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.

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 presen...

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Main Authors: Yaqin Xu, Anja Krause, Hiroko Hamai, Ben-Gary Harvey, Tilla S Worgall, Stefan Worgall
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2010-06-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC2882373?pdf=render
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author Yaqin Xu
Anja Krause
Hiroko Hamai
Ben-Gary Harvey
Tilla S Worgall
Stefan Worgall
author_facet Yaqin Xu
Anja Krause
Hiroko Hamai
Ben-Gary Harvey
Tilla S Worgall
Stefan Worgall
author_sort Yaqin Xu
collection DOAJ
description 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.
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spelling doaj.art-9d634fecd80c41739068f3cfb28a03392022-12-22T01:57:23ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-06-0156e1100410.1371/journal.pone.0011004Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.Yaqin XuAnja KrauseHiroko HamaiBen-Gary HarveyTilla S WorgallStefan WorgallThe 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.http://europepmc.org/articles/PMC2882373?pdf=render
spellingShingle Yaqin Xu
Anja Krause
Hiroko Hamai
Ben-Gary Harvey
Tilla S Worgall
Stefan Worgall
Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.
PLoS ONE
title Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.
title_full Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.
title_fullStr Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.
title_full_unstemmed Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.
title_short Proinflammatory phenotype and increased caveolin-1 in alveolar macrophages with silenced CFTR mRNA.
title_sort proinflammatory phenotype and increased caveolin 1 in alveolar macrophages with silenced cftr mrna
url http://europepmc.org/articles/PMC2882373?pdf=render
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