title: Inducible expression of microRNA-194 is regulated by HNF-1alpha during intestinal epithelial cell differentiation.
abstract: Maintenance of the intestinal epithelium is based on well-balanced molecular mechanisms that confer the stable and continuous supply of specialized epithelial cell lineages from multipotent progenitors. Lineage commitment decisions in the intestinal epithelium system involve multiple regulatory systems that interplay with each other to establish the cellular identities. Here, we demonstrate that the microRNA system could be involved in intestinal epithelial cell differentiation, and that microRNA-194 (miR-194) is highly induced during this process. To investigate this inducible expression mechanism, we identified the genomic structure of the miR-194-2, -192 gene, one of the inducible class of miR-194 parental genes. Furthermore, we identified its transcriptional regulatory region that contains a consensus-binding motif for hepatocyte nuclear factor-1alpha (HNF-1alpha), which is well known as a transcription factor to regulate gene expression in intestinal epithelial cells. By chromatin immunoprecipitation assay and luciferase reporter analysis, we revealed that pri-miR-194-2 expression is controlled by HNF-1alpha, and its consensus binding region is required for the transcription of pri-miR-194-2 in vivo in an intestinal epithelial cell line, Caco-2. Our observations indicate that microRNA genes could be targets of lineage-specific transcription factors and that microRNAs are regulated by a tissue-specific manner in the intestinal epithelium. Therefore, our work suggests that induced expression of these microRNAs have important roles in intestinal epithelium maturation.
authors.affiliation: Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University, Tokyo 113-8519, Japan.
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Hino
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Taro
authors.initials: T
authors.lastname: Fukao
authors.forename: Kotaro
authors.initials: K
authors.lastname: Kiga
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Okamoto
authors.forename: Takanori
authors.initials: T
authors.lastname: Kanai
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D002454:Cell Differentiation; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000166:cytology*; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000378:metabolism*; D006801:Humans; D007422:Intestines / Q000166:cytology*; D035683:MicroRNAs / Q000235:genetics*; D011401:Promoter Regions, Genetic
chemical_list: D051538:Hepatocyte Nuclear Factor 1-alpha; D035683:MicroRNAs