Kotaro Kadoya 1,2 , Shinsaku Togo 1,3 , Miniwan Tulafu 1,2 , Yukiko Namba 1,2 , Moe Iwai 1,2 , Junko Watanabe 1,2 , Takahiro Okabe 1,2 , Jin Jin 1,2,4 , Yuzo Kodama 1,2 , Hideya Kitamura 5 , Takashi Ogura 5 , Norikazu Kitamura 6 , Kazuho Ikeo 6,7 , Tadayuki Takeda 8 , Naoto Kondo 8 , Kazuhisa Takahashi 1,2 Show Affiliations »
Abstract
BACKGROUND/AIMS: Lung fibrosis is associated with lung tissue contraction due to abnormal accumulation of myofibroblasts, which aggressively promote the fibrotic process. Transforming growth factor (TGF)-β signaling in fibroblasts promotes extracellular matrix (ECM) synthesis and fibroblast migration and differentiation into myofibroblasts. Inhibition of extracellular signal-regulated kinase (ERK)5 blocks lung fibroblast activation by suppressing TGF-β signaling. Here, we examined the effects of an ERK5 inhibitor on TGF-β1-induced fibrosis in lung fibroblasts. METHODS: The effects of ERK5 inhibition following TGF-β1 exposure were evaluated in lung fibroblasts isolated from fibrotic human lung tissues. Fibroblast-mediated collagen gel contraction and fibroblast migration towards fibronectin were assessed. Phenotypic differences in fibrotic fibroblasts were examined using the cap analysis gene expression method for genome-wide quantification of promoter activity. RESULTS: TGF-β1stimulated contraction of collagen gels, fibroblast migration, and α-smooth muscle actin and fibronectin expression, and Smad3 phosphorylation were increased in fibrotic fibroblasts as compared to normal lung fibroblasts. Treatment with the ERK5 inhibitor blocked these responses to a greater extent in fibroblasts from patients with usual interstitial pneumonia as compared to nonspecific interstitial pneumonia, independent of bone morphogenetic protein/Smad1 regulation. Moreover, 223 genes including fibulin-5 -which is involved in the TGF-β1-ERK5 signaling network- were upregulated in fibrotic fibroblasts, and ECM regulation was found to be enriched in the Reactome analysis. CONCLUSION: ERK5 inhibition attenuated the high sensitivity of fibrotic fibroblasts to TGF-β1/Smad3 signaling. Thus, the ERK5 pathway components and fibulin-5 are potential therapeutic targets to prevent lung fibrosis progression. © Copyright by the Author(s). Published by Cell Physiol Biochem Press.
BACKGROUND/AIMS: Lung fibrosis is associated with lung tissue contraction due to abnormal accumulation of myofibroblasts, which aggressively promote the fibrotic process. Transforming growth factor (TGF)-β signaling in fibroblasts promotes extracellular matrix (ECM) synthesis and fibroblast migration and differentiation into myofibroblasts. Inhibition of extracellular signal-regulated kinase (ERK)5 blocks lung fibroblast activation by suppressing TGF-β signaling. Here, we examined the effects of an ERK5 inhibitor on TGF-β1-induced fibrosis in lung fibroblasts. METHODS: The effects of ERK5 inhibition following TGF-β1 exposure were evaluated in lung fibroblasts isolated from fibrotic human lung tissues. Fibroblast-mediated collagen gel contraction and fibroblast migration towards fibronectin were assessed. Phenotypic differences in fibrotic fibroblasts were examined using the cap analysis gene expression method for genome-wide quantification of promoter activity. RESULTS: TGF-β1stimulated contraction of collagen gels, fibroblast migration, and α-smooth muscle actin and fibronectin expression, and Smad3 phosphorylation were increased in fibrotic fibroblasts as compared to normal lung fibroblasts. Treatment with the ERK5 inhibitor blocked these responses to a greater extent in fibroblasts from patients with usual interstitial pneumonia as compared to nonspecific interstitial pneumonia , independent of bone morphogenetic protein /Smad1 regulation. Moreover, 223 genes including fibulin-5 -which is involved in the TGF-β1-ERK5 signaling network- were upregulated in fibrotic fibroblasts, and ECM regulation was found to be enriched in the Reactome analysis. CONCLUSION: ERK5 inhibition attenuated the high sensitivity of fibrotic fibroblasts to TGF-β1/Smad3 signaling. Thus, the ERK5 pathway components and fibulin-5 are potential therapeutic targets to prevent lung fibrosis progression. © Copyright by the Author(s). Published by Cell Physiol Biochem Press.
Entities: Disease
Gene
Species
Keywords:
Extracellular-signal-regulated kinase 5 (ERK5); Fibulin-5; Lung fibroblast; Smad; Transforming growth factor-β1 (TGF-β1)
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Year: 2019
PMID： 30946557 DOI： 10.33594/000000057
Source DB: PubMed Journal: Cell Physiol Biochem ISSN： 1015-8987