title: Regulatory System for Stem/Progenitor Cell Niches in the Adult Rodent Pituitary.
abstract: The anterior lobe of the pituitary gland is a master endocrine tissue composed of five types of endocrine cells. Although the turnover rate of pituitary endocrine cells is as low as about 1.6% per day, recent studies have demonstrated that Sex-determining region Y-box 2 (SOX2)⁺-cells exist as pituitary stem/progenitor cells in the adult anterior lobe and contribute to cell regeneration. Notably, SOX2⁺-pituitary stem/progenitor cells form two types of niches in this tissue: the marginal cell layer (MCL-niche) and the dense cell clusters scattering in the parenchyma (parenchymal-niche). However, little is known about the mechanisms and factors for regulating the pituitary stem/progenitor cell niches, as well as the functional differences between the two types of niches. Elucidation of the regulatory mechanisms in the niches might enable us to understand the cell regeneration system that acts in accordance with physiological demands in the adult pituitary. In this review, so as to reveal the regulatory mechanisms of the two types of niche, we summarize the regulatory factors and their roles in the adult rodent pituitary niches by focusing on three components: soluble factors, cell surface proteins and extracellular matrixes.
authors.affiliation: Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kanagawa 214-8571, Japan. saishu@meiji.ac.jp.|Institute of Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan. saishu@meiji.ac.jp.
authors.forename: Saishu
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kanagawa 214-8571, Japan. tf00002@isc.meiji.ac.jp.|Institute of Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan. tf00002@isc.meiji.ac.jp.
authors.forename: Takako
authors.initials: T
authors.lastname: Kato
authors.affiliation: Institute of Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan. yukato@isc.meiji.ac.jp.|Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan. yukato@isc.meiji.ac.jp.|Department of Life Science, School of Agriculture, Meiji University, Kanagawa 214-8571, Japan. yukato@isc.meiji.ac.jp.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kato
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D010902:Pituitary Gland / Q000166:cytology* / Q000378:metabolism; D012377:Rodentia; D015398:Signal Transduction; D055153:Stem Cell Niche
keywords: cell regeneration; niche; pituitary; signaling molecules; stem/progenitor cells