Isolation of adult pituitary stem/progenitor cell clusters located in the parenchyma of the rat anterior lobe

• Published in: Stem cell research Vol. 17; no. 2; pp. 318 - 329
• Main Authors: Yoshida, Saishu, Nishimura, Naoto, Ueharu, Hiroki, Kanno, Naoko, Higuchi, Masashi, Horiguchi, Kotaro, Kato, Takako, Kato, Yukio
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.09.2016; Elsevier
• Subjects: Adult Stem Cells - cytology; Adult Stem Cells - metabolism; Animals; Cadherins - metabolism; Cell Culture Techniques; Cell Differentiation - drug effects; Cells, Cultured; Epidermal Growth Factor - pharmacology; Fibroblast Growth Factor 2 - pharmacology; Glycogen Synthase Kinase 3 beta - antagonists & inhibitors; Glycogen Synthase Kinase 3 beta - metabolism; Homeodomain Proteins - metabolism; Immunohistochemistry; Male; Microscopy, Fluorescence; Pituitary; Pituitary Gland, Anterior - cytology; PROP1; Rats; Rats, Transgenic; Rats, Wistar; S100 Calcium Binding Protein beta Subunit - metabolism; S100β; SOX2-positive-cluster; SOXB1 Transcription Factors - genetics; SOXB1 Transcription Factors - metabolism; Stem/progenitor cell niche; Ephrin; PS-cluster; PROP1; SOX2-positive-cluster; EGF; DAPI; KSR; TBX19; bFGF; ECM; GFP; SOX2; GSK3β; FITC; PIT1; Stem/progenitor cell niche; CAR; Pituitary; MCL; PI; S100β; BrdU; SF1
• ISSN: 1873-5061; 1876-7753; 1876-7753
• DOI: 10.1016/j.scr.2016.08.016

Recent studies have demonstrated that Sox2-expressing stem/progenitor cells play roles in the pituitary cell turnover. Two types of niches have been proposed for stem/progenitor cells, the marginal cell layer (MCL) and the dense cell clusters in the parenchyma. Among them, the appearance of the parenchymal-niche only after birth indicates that this niche is involved in the cell turnover required for the postnatal pituitary. However, little is known about the roles of the parenchymal-niche and its regulation. The present study aimed to isolate pituitary stem/progenitor cells from the parenchymal-niche in the adult rat pituitary. Cell dispersion by stepwise treatment with proteases allowed the isolation of dense cell clusters. Immunocytochemistry demonstrated that clusters are universally composed of SOX2-positive cells, and most of them are positive for PROP1. Taken together with the anatomical analysis, we concluded that the isolated clusters are the parenchymal stem/progenitor cell (PS)-clusters, not the MCL-one. PS-clusters cultivated by serum-free overlay 3-dimensional culture maintained their stemness, and treatment with bFGF and EGF induced cyst-formation. Moreover, PS-clusters demonstrated some differentiation capacity with GSK3β-inhibitor treatment. Collectively, the present study demonstrates a simple method for isolating stem/progenitor cells from the parenchymal-niche, and provides tools to analyze the factors for regulating the pituitary niches. •Isolation of the pituitary stem/progenitor cell niche forming dense cell cluster.•Dense cell clusters are classified into three subtypes referring to S100β.•Cultivation by the serum-free 3D culture maintains their undifferentiated state.•Inhibition of GSK3β induces PS-cluster to differentiate into hormone-producing cells.