CYPZE1-mediated oxidative stress induces collagen type I expression in rat hepatic stellate cells
CYPZE1-mediated oxidative stress induces collagen type I expression in rat hepatic stellate cells
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DOI：
10.1002/hep.510300433
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发表时间：
1999-10-01
期刊：
影响因子：
13.5
通讯作者：
Cederbaum, AI
中科院分区：
文献类型：
--
作者：
Nieto, N;Friedman, SL;Cederbaum, AI
肝星状细胞（HSC）是细胞外基质的主要来源，其在纤维形成期间经历以增加的增殖和胶原合成为特征的“活化”过程。氧化应激可刺激HSC增殖和胶原合成。细胞色素P4502 E1（CYP 2 E1）是活性氧的有效生产者。为了研究细胞内氧化应激如何调节α 2胶原I型（COL 1A 2）基因的诱导，用人CYP 2 E1互补DNA以正义和反义方向以及空载体转染大鼠HSC系（HSC-T6），并产生稳定的细胞系。表达CYP 2 E1的细胞显示活性氧的产生增加，并显示COL 1A 2信使RNA（mRNA）水平增加4倍;不同克隆中该mRNA的表达似乎与CYP 2 E1水平相关。维生素E处理或锰超氧化物歧化酶转染可降低COL 1A 2的表达，而L-丁硫基亚砜亚胺（BSO）处理降低GSH水平后，COL 1A 2的表达进一步增加。因此，CYP 2 E1依赖的氧化应激在该系统中COL 1A 2 mRNA水平升高中起主要作用。核连续试验显示，在表达CYP 2 E1的细胞中，COL 1A 2转录增加了3.5倍;还观察到COL 1A 2 mRNA的稳定。这些结果表明，在氧化应激条件下，COL 1A 2 mRNA表达的转录和通过mRNA稳定调节。表达CYP 2 E1的HSC似乎是持续产生活性氧的有价值的模型，并可能允许阐明负责氧化应激介导的胶原基因诱导的信号传导途径。
Hepatic stellate cells (HSCs) are a major source of extracellular matrix, which, during fibrogenesis, undergo a process of "activation" characterized by increased proliferation and collagen synthesis. Oxidative stress can stimulate HSC proliferation and collagen synthesis in vitro. Cytochrome P4502E1 (CYP2E1) is an effective producer of reactive oxygen species. To study how intracellular oxidative stress modulates alpha 2 collagen type I (COL1A2) gene induction, a rat HSC line (HSC-T6) was transfected with human CYP2E1 complementary DNA in the sense and antisense orientation and with empty vector, and stable cell lines were generated. The cells expressing CYP2E1 displayed elevated production of reactive oxygen species and showed a 4-fold increase in COL1A2 messenger RNA (mRNA) levels; expression of this mRNA among different clones appeared to correlate with the level of CYP2E1. COL1A2 expression was decreased by vitamin E treatment or transfection with manganese superoxide dismutase, and was further increased after treatment with L-buthionine sulfoximine (BSO) to lower GSH levels, Thus, CYP2E1-dependent oxidative stress plays a major role in the elevation of COL1A2 mRNA levels in this system. Nuclear run-on assay showed a 3-and-a-half-fold increase in COL1A2 transcription in the cells expressing CYP2E1; stabilization of COL1A2 mRNA was also observed. These results indicate that under oxidative stress conditions, COL1A2 mRNA expression is regulated both transcriptionally and through mRNA stabilization. The CYP2E1-expressing HSC appear to be a valuable model for the sustained generation of reactive oxygen species and may allow the elucidation of signaling pathways responsible for oxidant stress-mediated collagen gene induction.