Fibronectin-mediated hepatocyte shape change reprograms cytochrome p450 2C11 gene expression via an integrin-signaled induction of ribonuclease activity
Fibronectin-mediated hepatocyte shape change reprograms cytochrome p450 2C11 gene expression via an integrin-signaled induction of ribonuclease activity
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DOI：
10.1124/mol.58.5.976
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发表时间：
2000-11-01
影响因子：
3.6
通讯作者：
Paine, AJ
中科院分区：
文献类型：
--
作者：
Hodgkinson, CP;Wright, MC;Paine, AJ
在药物代谢和毒性研究中使用大鼠肝细胞的一个主要限制是CYPs的快速损失。我们证明，大鼠肝细胞的培养导致肝脏特异性CYP2C11 mRNA和编码一般管家基因铜锌超氧化物歧化酶（CuZnSOD）以及聚（a (+)） mRNA的转录物的快速丢失。纤维连接蛋白加速了这些损失，而对CYP2C11和CuZnSOD的转录没有影响。然而，纤维连接蛋白是一种参与细胞粘附和扩散的细胞外基质蛋白，可诱导核糖核酸酶（RNase）活性。纤维连接蛋白也增加肝细胞直径，数据显示细胞扩散与CYP2C11和CuZnSOD mrna的丢失有关。功能性阻断抗体的使用表明，纤维连接蛋白通过其α (5) β(1)整合素受体和染料木素（一种酪氨酸激酶抑制剂）起作用，阻止肝细胞扩散、RNase诱导和CYP2C11 mRNA丢失。总的来说，这些数据表明，体外肝细胞通过纤维连接蛋白的自分泌作用积极促进其表型的消失，而不是目前的共识，即它们只是通过缺乏细胞外基质蛋白而失去分化功能，如CYP2C11的表达。还考虑了诱导的核糖核酸酶的底物特异性。
A major limitation to the use of rat hepatocytes in the study of drug metabolism and toxicity is the rapid loss of CYPs. We demonstrate that the culture of rat hepatocytes results in a rapid loss of liver-specific CYP2C11 mRNA and transcripts encoding the general housekeeping gene copper-zinc superoxide dismutase (CuZnSOD) as well as poly(A(+)) mRNA. These losses are accelerated by fibronectin, which has no effect on the transcription of CYP2C11 and CuZnSOD. However, fibronectin, an extracellular matrix protein involved in cell adhesion and spreading, induces ribonuclease (RNase) activity. Fibronectin also increases hepatocyte diameter and data are presented that cell spreading is involved in the loss of both CYP2C11 and CuZnSOD mRNAs. The use of functional blocking antibodies demonstrates that fibronectin is operating through its alpha(5)beta(1) integrin receptor and genistein, a tyrosine kinase inhibitor, prevents hepatocyte spreading, RNase induction, and CYP2C11 mRNA loss. Collectively, the data indicate that hepatocytes in vitro actively promote the extinction of their phenotype via the autocrine effects of fibronectin rather than the current consensus that they simply lose differentiated function, such as CYP2C11 expression, through the absence of extracellular matrix proteins. The substrate specificity of the ribonuclease induced is also considered.