Liver-Enriched Transcription Factors

为了评估肝细胞核因子4α (hnf4α)在成人肠道中的功能，利用Cre转基因小鼠制备了肠上皮细胞特异性hnf4α缺失小鼠系，在小鼠绒毛蛋白启动子的控制下，Cre基因在肠道中表达。这些小鼠表现出多糖和酸性粘多糖的轻微减少和粘蛋白、水通道蛋白和meprins等基因的表达改变。肠道特异性hnf4α缺失小鼠对葡聚糖硫酸钠诱导的炎症性肠病（IBD）的易感性增加，包括肠道通透性增加。这些发现表明，HNF4alpha可能在预防炎症性肠病方面发挥重要作用。成功培养了肠上皮细胞中缺乏hnf4α基因表达的小鼠。northern blot和免疫组化方法观察了HNF4alpha基因敲除小鼠肠道内HNF4alpha基因mRNA和蛋白水平的破坏。血清甘油三酯、胆固醇和磷脂水平在HNF4alpha肠道特异性敲除小鼠小鼠正常。HNF4alpha肠道特异性敲除小鼠结肠中多糖和酸性粘多糖水平降低。在HNF4alpha肠道特异性敲除小鼠的结肠中，mucin3、aquaporins1和8、meprin1alpha和1beta的表达也显著降低，而mucin1的表达也明显增加。经葡聚糖硫酸钠处理后，HNF4alpha肠道特异性敲除小鼠小鼠与对照小鼠相比出现了显著的严重变化，包括体重、结肠长度、细胞因子水平、组织学形态和肠道通透性的减少。总之，由于上皮屏障通透性增加，HNF4alpha肠道特异性敲除小鼠对葡聚糖硫酸钠诱导的炎症性肠病表现出更高的易感性。这些数据表明，HNF4alpha可能在保护肠道免受炎症性损伤方面发挥重要作用。

In order to assess the function of hepatocyte nuclear factor 4alpha (HNF4alpha) in adult intestine, an intestinal epithelial cell-specific Hnf4alpha-null mouse line was produced using Cre transgenic mice in which the Cre gene is expressed in the intestine under the control of the mouse villin promoter. These mice exhibited slight decrease of polysaccharides and acidic mucopolysaccharides and altered expression of several genes such as mucins, aquaporins, and meprins. Gut-specific Hnf4alpha-null mice exhibited increased susceptibility to dextran sulfate sodium-induced inflammatory bowel disease (IBD), including increased intestinal permeability. These findings show that HNF4alpha may have an important role in protecting against inflammatory bowel disease. Mice lacking expression of the HNF4alpha gene in intestinal epithelial cells were successfully developed. Disruption of both mRNA and protein level of HNF4alpha were observed in intestine of HNF4alpha intestine-specific knockout mice by northern blot and immunohistochemistry. The levels of serum triglyceride, cholesterol, and phospholipids in HNF4alpha intestine-specific knockout mice mice were normal. The levels of polysaccharides and acidic mucopolysaccharides were decreased in the colon of HNF4alpha intestine-specific knockout mice. A marked decreased expression of mucin3, aquaporins1 and 8, and meprin1alpha and 1beta, and increased expression of mucin1 was also detected in the colon of HNF4alpha intestine-specific knockout mice. After dextran sulfate sodium treatment, HNF4alpha intestine-specific knockout mice mice showed significant severe changes, including loss of body weight, colon length, cytokine levels, histological morphology, and intestinal permeability, compared with control mice. In conclusion, HNF4alpha intestine-specific knockout mice showed higher susceptibility to dextran sulfate sodium-induced inflammatory bowel disease as a result of increased permeability of the epithelial barrier. These data indicate HNF4alpha may play an important role in protection against intestinal inflammatory insult.