Sucrase-isomaltase gene expression is inhibited by mutant hepatocyte nuclear factor (HNF)-1α and mutant HNF-1β in Caco-2 cells
Sucrase-isomaltase gene expression is inhibited by mutant hepatocyte nuclear factor (HNF)-1α and mutant HNF-1β in Caco-2 cells
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DOI：
10.3177/jnsv.52.105
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发表时间：
2006-04-01
影响因子：
1.6
通讯作者：
Yasuda, K
中科院分区：
文献类型：
--
作者：
Gu, N;Adachi, T;Yasuda, K
肝细胞核因子(HNF)-1α和HNF-1β参与蔗糖酶异麦芽糖酶(SI)基因的表达，并直接结合两个位点(SIF2)。SI基因FILE启动子的SIF3)。然而，ChAT HNF-1α和HNF-1β在SI基因表达调控中的作用尚不完全清楚。为了阐明HNF-1α和HNF-1β调控SI基因表达的机制，我们以肠上皮样细胞系Caco-2为基础，建立了四个稳定的细胞系，野生型HNF-1α和野生型HNF-1β。否则突变型HNF-1αT539fsdelC或突变型HNF-1βR177X过表达。在HNF-1αT539fsdelC细胞和HNF-1βR177X细胞中表达，而在野生型HNF-1α细胞和野生型HNF-1β细胞中不表达。与Caco-2细胞相比，SI基因的表达和酶活性显著降低。此外，为了弄清这些转基因过表达是否会影响细胞的稳定分化，还检测了碱性磷酸酶(ALP)基因的表达和酶活性。ALP基因表达和酶活性无明显变化。这些观察结果表明，突变的HNF-1αT539fsdelC和突变的HNF-1βR177X在转录水平上抑制SI基因。导致Caco-2细胞SI酶活性降低。我们认为HNF-1α和HNF-1β在分化的Caco-2细胞中都参与了SI基因的结构性表达。
Hepatocyte nuclear factor (HNF)-1 alpha and HNF-1 beta are concerned in sucrase-isomaltase (SI) gene expression, and directly bind two sites (SIF2. SIF3) of file promoter of the SI gene. However, it is not completely clear Chat HNF-1 alpha and HNF-1 beta play a role in regulation of SI gene expression. To clarify mechanisms of SI gene expression regulated by HNF-1 alpha and HNF-1 beta, we established four stable cell lines based on enterocyte-like cell line Caco-2, in which wild HNF-1 alpha or wild HNF-1 beta. or else Mutant HNF-1 alpha T539fsdelC or mutant HNF-1 beta R177X was overexpressed. In the HNF-1 alpha T539fsdelC cells and HNF-1 beta R177X cells, but not in the wild HNF-1 alpha cells and wild HNF-1 beta cells. SI gene expression and enzyme activity were significantly diminished compared with that in Caco-2 cells. Moreover, to clarify whether or not stable cell differentiation was influenced by overexpression of these transgenes, alkaline phosphatase (ALP) gene expression and enzyme activity were measured. There were no changes in ALP gene expression or enzyme activity in these cells. These observations suggest that mutant HNF-1 alpha T539fsdelC and mutant HNF-1 beta R177X inhibits SI gene at the transcriptional level. resulting in decreased SI enzyme activity in Caco-2 cells. We propose that both HNF-1 alpha and HNF-1 beta would contribute to Constitutive expression of the SI gene in the differentiated state ill Caco-2 cells.