Modulation of gene expression of transforming growth factor-α by ethanol in ethano-exposed hepatocytes

乙醇对暴露于乙醇的肝细胞中转化生长因子-α基因表达的调节

• 批准号: 11670519
• 负责人: KATO Junji
• 金额: $ 2.18万
• 依托单位: SAPPORO MEDICAL UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670519/
• 关键词: Alcoholic liver fibrosis; TGF-α; ethanol; Hepatic ctellate cells; HepG2 cells; IMR-90 cells; NF-kB; Oxidative damage; アルコール性肝線維症; Stellate cell; collagen; ethanol

Liver fibrosis often develops in alcoholic liver diseases without accompanying inflammation, however the underlying mechanism is unclear. Using ethanol-exposed human HepG2 hepatoblastoma cells as a model for alcoholic liver diseases, we found previously that ethanol exposure causes HepG2 cells to secrete transforming growth factor-α (TGF-α) which stimulates collagen synthesis in human IMR-90 fibroblasts and rat hepatic stellate cells. The aim of this study was to investigate the mechanism of TGF-α gene expression by ethanol. TGF-α mRNA and protein expression by Northern and Western bolt, respectively. Gel mobility shift assay for NF-kB for the promotor region of TGF-α gene was examined. Northern and Western blot analyses showed increased TGF-α mRNA and protein expression in ethanol-treated HepG2 cells. Ethanol-treatment increased degradation of IkB and enhanced TGF-α transcription via NF-kB.Ethano-induced NF-kB activation and TGF-α transcription were blocked in the presence of anti-oxidant, NAC, suggesting that production of reactive oxygen species is inplicated in this signaling. In conclusion, TGF-α is considered to contribute to the development of hepatic fibrosis in alcoholic liver diseases.

酒精性肝病常发生肝纤维化，但不伴有炎症反应，其机制尚不清楚。我们使用乙醇暴露的人HepG 2肝母细胞瘤细胞作为酒精性肝病的模型，先前发现乙醇暴露导致HepG 2细胞分泌转化生长因子-α（TGF-α），其刺激人IMR-90成纤维细胞和大鼠肝星状细胞中的胶原合成。本研究旨在探讨乙醇诱导TGF-α基因表达的机制。分别用北方杂交和Western杂交检测TGF-α mRNA和蛋白表达。采用凝胶迁移率变动法检测TGF-α基因启动子区NF-κ B的表达。北方和Western blot分析显示乙醇处理的HepG 2细胞中TGF-α mRNA和蛋白表达增加。乙醇处理增加了IkB的降解，并通过NF-κ B增强了TGF-α的转录。在抗氧化剂NAC存在下，乙醇诱导的NF-κ B活化和TGF-α的转录被阻断，表明活性氧的产生与此信号传导有关。总之，TGF-α被认为有助于酒精性肝病肝纤维化的发展。

项目成果

Lu L,Sakamaki S,Kato J, et al: "Prevention of lethal acute graft-versus-host disease in mice by oral administration of T helper 1 inhibitor,TAK-603."Blood. 97. 1123-1130 (2001)

Lu L、Sakamaki S、Kato J 等人：“通过口服 T 辅助细胞 1 抑制剂 TAK-603 预防小鼠致命性急性移植物抗宿主病。”血液。

Matsunaga T, Sakamaki S, Kato J, et al.: "Use of PCR serum in diagnosing and monitoring cytomegalovirus reactivation in bone marrow transplant recipients."Int J Hematol. 69. 105-111 (1999)

Matsunaga T、Sakamaki S、Kato J 等人：“使用 PCR 血清诊断和监测骨髓移植受者巨细胞病毒再激活。”Int J Hematol。

Takayama T., Kato J., et al: "Aberrant crypt foci of the colon as precursors of adenoma and cancer."New England Journal of Medicine. 339. 1277-1284 (1998)

Takayama T.、Kato J. 等人：“结肠的异常隐窝灶是腺瘤和癌症的前兆。”新英格兰医学杂志。

Sakamaki S, Takayanagi N, Kato J, et al.: "Auto-antibodies against the specific epitope of human tropomyosin (s) detected by a peptide-based enzyme immunoassay in sera of patients with ulcerative colitis show antibody dependent cell-mediated cytotoxicity

Sakamaki S、Takayanagi N、Kato J 等人：“通过基于肽的酶免疫测定法在溃疡性结肠炎患者血清中检测到针对人原肌球蛋白特定表位的自身抗体，显示出抗体依赖性细胞介导的细胞毒性

Sakamaki S, Hirayama Y, Kato J, et al.: "Transforming growth factor-β1 (TGF-β1) induces thrombopoietin from bone marrow stromal cells, which stimulates the expression of TGF-β receptor on megakaryocytes and, in turn, renders them susceptible to suppressio

Sakamaki S、Hirayama Y、Kato J 等人：“转化生长因子-β1 (TGF-β1) 诱导骨髓基质细胞产生血小板生成素，刺激巨核细胞上 TGF-β 受体的表达，进而使巨核细胞生成血小板生成素。容易受到抑制