Are folliculo-stellate cells in the anterior pituitary gland supportive cells or organ-specific stem cells?
Folliculo-stellate cells (FS-cells) in the anterior pituitary gland are star-shaped cells and form tiny follicles. FS-cells are positive for S-100 protein and produce many cytokines or growth factors, such as interleukin-6 (IL-6), leukemia inhibitory factor (LIF), basic fibroblastic growth factor (bFGF) and vascular endothelial cell growth factor (VEGF). Therefore, it is generally accepted that FS-cells regulate endocrine cells through these growth factors. FS-cells also exhibit a phagocytotic activity and are known to work as scavenger cells. In addition to these functions, FS-cells are considered to have some unknown functions. In order to reveal the biological significance of FS-cells in the anterior pituitary gland, we performed a morphological study and obtained some new findings. First, we were interested in the colloid formation in the senescent porcine pituitary gland. We analyzed the colloids and found that clusterin is a major protein in them. We also found that the accumulation of clusterin in the colloids is related to the phagocytotic activity of FS-cells. In our next study, we found that FS-cells have the potential to differentiate into striated muscle cells. From FS-cells show multi-potent cell character and other cytological evidence, we propose that FS-cells are candidate of organ-specific stem cells in the anterior pituitary gland.
Inoue
K
K
Department of Regulation Biology, Faculty of Science, Saitama University, Urawa, Japan. kininoue@seitai.saitama-u.ac.jp
Mogi
C
C
Ogawa
S
S
Tomida
M
M
Miyai
S
S
D000818:Animals; D051152:Clusterin; D006023:Glycoproteins / Q000502:physiology; D018832:Molecular Chaperones / Q000502:physiology; D018482:Muscle, Skeletal / Q000166:cytology / Q000648:ultrastructure; D009928:Organ Specificity; D010903:Pituitary Gland, Anterior / Q000166:cytology* / Q000502:physiology / Q000637:transplantation / Q000648:ultrastructure; D013234:Stem Cells / Q000502:physiology*
D051152:Clusterin; D006023:Glycoproteins; D018832:Molecular Chaperones