title: Expression of Krüppel-like factor 6, KLF6, in rat pituitary stem/progenitor cells and its regulation of the PRRX2 gene.
abstract: Paired-related transcription factors, PRRX1 and PRRX2, which are present in mesenchymal tissues and participate in mesenchymal cell differentiation, were recently found in the stem/progenitor cells of the pituitary gland of ectodermal origin. To clarify the role of PRRX1 and PRRX2 in the pituitary gland, the present study first aimed to identify transcription factors that regulate Prrx1 and Prrx2 expression. A promoter assay for the upstream regions of both genes was performed by co-transfection of the expression vector of several transcription factors, many of which are frequently found in the pituitary stem/progenitor cells. The results for the promoter activity of both genes showed expression in a cell type-dependent manner. Comprehensive comparison of transcriptional activity of several transcription factors was performed with CHO cells, which do not show Prrx1 and Prrx2 expression, and the results revealed the presence of common and distinct factors for both genes. Among them, KLF6 showed specific and remarkable stimulation of Prrx2 expression. In vitro experiments using an electrophoretic mobility shift assay and siRNA interference revealed a potential ability for regulation of Prrx2 expression by KLF6. Finally, immunohistochemistry confirmed the presence of KLF6 in the SOX2/PRRX2 double-positive stem/progenitor cells of the postnatal pituitary gland. Thus, the finding of KLF6 might provide a novel clue to clarify the maintenance of stem/progenitor cells of the postnatal pituitary gland.
authors.affiliation: Laboratory of Molecular Biology and Gene Regulation, Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueharu
authors.forename: Masashi
authors.initials: M
authors.lastname: Higuchi
authors.forename: Naoto
authors.initials: N
authors.lastname: Nishimura
authors.forename: Saishu
authors.initials: S
authors.lastname: Yoshida
authors.forename: Shiori
authors.initials: S
authors.lastname: Shibuya
authors.forename: Kenta
authors.initials: K
authors.lastname: Sensui
authors.forename: Takako
authors.initials: T
authors.lastname: Kato
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kato
mesh_terms: D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D055785:Gene Knockdown Techniques; D018398:Homeodomain Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D017208:Rats, Wistar; D013234:Stem Cells / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D018398:Homeodomain Proteins; C491357:Klf6 protein, rat; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors; C528022:PRRX1 protein, rat; D011518:Proto-Oncogene Proteins; C586264:Prrx2 protein, rat; D014157:Transcription Factors