Development of regenerative medicine and therapeutic system for hepatic failure applied by hepatocyte nuclear factor 4

我们将腺病毒介导的HNF-4转染到肝祖细胞中，分析其肝脏特异性功能的表达情况。腺病毒介导的HNF-4基因转移导致HNF-4、载脂蛋白（Apo） A1、apo3和妊娠X受体（PXR） mRNA的表达增加。然后将过表达hnf -4的肝祖细胞注射到受体小鼠体内，用二甲基亚硝胺和30%肝部分切除术处理。实验组小鼠的存活时间明显长于对照组小鼠。用转染了HNF-4的细胞处理的小鼠的血浆白蛋白、总胆固醇和葡萄糖水平高于对照小鼠。雄性Wistar大鼠皮下注射2-乙酰氨基芴。7天后，他们接受了70%的部分肝切除术，并感染了携带HNF-4或Lac-Z cDNA的重组腺病毒。在HNF-4处理的大鼠中，卵形细胞的总数显著减少。此时，HNF-4处理的大鼠肝细胞增殖受到抑制，同时肝细胞分化标志物HNF-4、载脂蛋白CIII、酪氨酸氨基转移酶和白蛋白mRNA表达增加。相反，作为胆道上皮细胞分化标志的细胞角蛋白-19 mRNA表达在HNF-4转移的大鼠肝脏中下降。这些发现表明，腺病毒介导的HNF-4转染在体外诱导肝祖细胞向肝实质细胞分化，这些细胞可能是肝脏疾病细胞移植的有用来源。转染HNF-4基因可促进肝卵圆细胞向肝细胞的分化。

We transfected adenovirus-mediated HNF-4 into hepatic progenitor cells, and analyzed the expressions of the liver-specific functions. Adenovirus-mediated HNF-4 gene transfer resulted in increases in the expressions of HNF-4, apolipoprotein (Apo) A1 ApoC3, and pregnane X receptor (PXR) mRNA. HNF-4-overexpressing hepatic progenitor cells were then injected into recipient mice, which were treated with dimethylnitrosamine and 30% partial hepatectomy. The treated mice survived significantly longer than the control mice. The plasma levels of albumin, total cholesterol, and glucose were higher in the mice treated with cells transfected by HNF-4 than in the control mice. Male Wistar rats were administered 2-acetylaminofluorene subcutaneously. Seven days later, they received 70% partial hepatectomy and infected with a recombinant adenovirus carrying the cDNA for HNF-4 or Lac-Z. The total numbers of oval cells significantly decreased in the HNF-4 treated rats. At this point, HNF-4-treated rats experienced an inhibition of liver cell proliferation, while mRNA expressions of HNF-4, apolipoprotein CIII, tyrosine amino transferase and albumin, markers for the differentiation of hepatocytes, increased. In contrast, mRNA expression of cytokeratin-19, a marker for the differentiation of biliary epithelial cells, decreased in the livers of HNF-4 transferred rats. These findings demonstrate that adenovirus-mediated HNF-4 transfection induces the differentiation from hepatic progenitor cells to hepatic parenchymal cells in vitro and that these cells may be useful as a source for cell transplantation in liver diseases. The transfer of HNF-4 gene could accelerate the differentiation of hepatic oval cells to hepatocytes.