Glucocorticoids modulate TGF-beta production by human fetal lung fibroblasts.
TGF-beta1 is thought to play a central role in pulmonary fibrosis inducing fibroblast differentiation and extracellular matrix synthesis. In human lung fibroblasts, it is still unclear how various TGF-beta isoforms affect TGF-beta production and whether glucocorticoids, commonly used agents to treat fibrotic lung disease, modulate these processes. To this end, human fetal lung fibroblasts (HFLF) were cultured with various concentrations of glucocorticoids (budesonide, dexamethasone or hydrocortisone) with and without TGF-beta1, -beta2, or -beta3. Post-culture media were collected for ELISA assays of TGF-beta1, -beta2, and -beta3. TGF-beta mRNA was assessed by real time RT-PCR. Smad 2, 3, and 4 and AP-1 complex (c-fos and c-Jun) cellular localization were evaluated by immunostaining. TFG-beta2 and -beta3 stimulated TGF-beta1 production significantly (p < 0.01 relative to control). TGF-beta1 stimulated TGF-beta2 production (p < 0.01 relative to control). TGF-beta3 was undetectable. Glucocorticoids significantly inhibited TGF-beta1 and TGF-beta2 production and reduced expression of the up-regulated TGF-beta1 and TGF-beta2 mRNA induced by exogenous TGF-beta1, -beta2, or -beta3 (p < 0.01 for each) but had no effect on Smads. Although c-jun-related nuclear staining was not intensified in TGF-beta-stimulated cells, it was reduced by glucocorticoids. Thus, TGF-beta isoforms may stimulate production of various TGF-beta isoforms in the lung. Glucocorticoids then may block TGF-beta production by modulating mRNA levels and c-Jun.
Wen
Fu-Qiang
FQ
Pulmonary and Critical Care Medicine Section, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198-5125, USA.
Kohyama
Tadashi
T
Sköld
C Magnus
CM
Zhu
Yun Kiu
YK
Liu
Xiangde
X
Romberger
Debra J
DJ
Stoner
Julie
J
Rennard
Stephen I
SI
D002478:Cells, Cultured; D004336:Drug Antagonism; D005333:Fetus; D005347:Fibroblasts / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D008168:Lung / Q000166:cytology; D020033:Protein Isoforms / Q000494:pharmacology; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis; D015534:Trans-Activators / Q000187:drug effects; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3
D005938:Glucocorticoids; D020033:Protein Isoforms; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; C508960:TGFB1 protein, human; C509041:TGFB2 protein, human; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3