Conditional enhancement of liver-specific gene transcription.
Conditional enhancement of liver-specific gene transcription.
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DOI：
10.1073/pnas.85.23.9076
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发表时间：
1988-12
影响因子：
11.1
通讯作者：
K. Zaret;C. DiPersio;D. Jackson;W. Montigny;Debra L. WEINSTATt
中科院分区：
文献类型：
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作者：
K. Zaret;C. DiPersio;D. Jackson;W. Montigny;Debra L. WEINSTATt
我们试图开发一种可以随意诱导肝脏特异性转录的细胞系，以便于研究引起小鼠血清白蛋白基因肝细胞特异性转录的因素。因此，我们从用猿猴病毒40的温度敏感株感染的小鼠肝细胞中创建了H2.35细胞系。在允许温度下的常规繁殖期间，H2.35细胞表现出极低水平的白蛋白转录和mRNA。当H2.35细胞在限制性温度和胶原基质上的无血清培养基中培养时，白蛋白mRNA增加至少100倍;后两种条件维持原代肝细胞培养物的分化状态。虽然mRNA增加的主要原因是转录后，白蛋白和其他肝脏特异性基因的转录速率显着增加。瞬时转染实验表明，转录诱导是由白蛋白上游序列的激活引起的，该白蛋白上游序列先前被证明能增强转基因小鼠的肝脏特异性转录。因此，肝细胞分化似乎部分地通过刺激组织特异性增强子元件的活性的细胞外信号来维持。
We sought to develop a cell line in which liver-specific transcription could be induced at will, to facilitate the study of factors that cause hepatocyte-specific transcription of the serum albumin gene in mice. We therefore created the H2.35 cell line from mouse hepatocytes infected with a temperature-sensitive strain of simian virus 40. During routine propagation at the permissive temperature, H2.35 cells exhibit extremely low levels of albumin transcription and mRNA. Albumin mRNA increases at least 100-fold when H2.35 cells are cultured at the restrictive temperature and in serum-free medium on a collagen substratum; the two latter conditions maintain the differentiated state of primary hepatocyte cultures. Although a major cause of the mRNA increase is posttranscriptional, the transcription rates of albumin and other liver-specific genes increase significantly. Transient-transfection experiments demonstrated that an induction of transcription is caused by activation of an albumin upstream sequence that was previously shown to enhance liver-specific transcription in transgenic mice. Thus, hepatocyte differentiation appears to be maintained in part by extracellular signals that stimulate the activity of a tissue-specific enhancer element.