ヨシダ　カツノリ   YOSHIDA K.   吉田　勝紀    所属   関西医科大学  内科学第三講座    職種   講師
論文種別	原著(症例報告除く)
言語種別	英語
査読の有無	査読あり
表題	Chronic inflammation associated with hepatitis C virus infection perturbs hepatic transforming growth factor beta signaling, promoting cirrhosis and hepatocellular carcinoma.
掲載誌名	正式名：Hepatology 略　 称：Hepatology ISSNコード：02709139/15273350
巻・号・頁	46(1),pp.48-57
著者・共著者	Matsuzaki K, Murata M, Yoshida K, Sekimoto G, Uemura Y, Sakaida N, Kaibori M, Kamiyama Y, Nishizawa M, Fujisawa J, Okazaki K, Seki T
発行年月	2007/07
概要	Many patients with chronic hepatitis caused by hepatitis C virus (HCV) infection develop liver fibrosis with high risk for hepatocellular carcinoma (HCC), but the mechanism underling this process is unclear. Conversely, transforming growth factor beta (TGF-beta) activates not only TGF-beta type I receptor (TbetaRI) but also c-Jun N-terminal kinase (JNK), which convert the mediator Smad3 into two distinctive phosphoisoforms: C-terminally phosphorylated Smad3 (pSmad3C) and linker-phosphorylated Smad3 (pSmad3L). Whereas the TbetaRI/pSmad3C pathway suppresses epithelial cell growth by upregulating p21(WAF1) transcription, JNK/pSmad3L-mediated signaling promotes extracellular matrix deposition, partly, by upregulating plasminogen activator inhibitor 1 (PAI-1). We studied the domain-specific Smad3 phosphorylation in biopsy specimens representing chronic hepatitis, cirrhosis, or HCC from 100 patients chronically infected with HCV, and correlated Smad3 phosphorylation with clinical course. As HCV-infected livers progressed from chronic hepatitis through cirrhosis to HCC, hepatocytic pSmad3L/PAI-1 increased with fibrotic stage and necroinflammatory grade, and pSmad3C/p21(WAF1) decreased. Of 14 patients with chronic hepatitis C with strong hepatocytic pSmad3L positivity, 8 developed HCC within 12 years; only 1 of 12 showing little pSmad3L positivity developed HCC. We further sought molecular mechanisms in vitro. JNK activation by the pro-inflammatory cytokine interleukin-1beta stimulated the pSmad3L/PAI-1 pathway in facilitating hepatocytic invasion, in the meantime reducing TGF-beta-dependent tumor-suppressive activity by the pSmad3C/p21(WAF1) pathway. CONCLUSION: These results indicate that chronic inflammation associated with HCV infection shifts hepatocytic TGF-beta signaling from tumor-suppression to fibrogenesis, accelerating liver fibrosis and increasing risk for HCC.
文献番号	17596875