title: Glycine regulates proliferation and differentiation of salivary-gland-derived progenitor cells.
abstract: Amino acids have various physiological activities that influence processes such as intestinal regeneration, EGF secretion, protein synthesis, and cell growth. Salivary glands are exposed to nutrients that influence their proliferation and regeneration. Glycine is included in saliva in large quantities and reportedly has important roles in antibacterial activities and the inhibition of tumor growth and as a precursor of nucleotide synthesis in cell proliferation. We have investigated the effects of glycine on the proliferation and differentiation of salivary glands by using mouse salivary-gland-derived progenitor (mSGP) cells. In cultures of mSGP cells, cell proliferation is suppressed in the presence of glycine, whereas it is promoted by its removal. Glycine promotes three-dimensional formations of mSGP cells, which are negative for immature markers and positive for differentiation markers. In cell-cycle analysis, cell-cycle progression is delayed at the S-phase by glycine supplementation. Glycine also suppresses the phosphorylation of p42/p44MAPK. These results suggest that glycine suppresses the proliferation and promotes the differentiation of mSGP cells, and that it has inhibitory effects on growth factor signaling and cell-cycle progression. Glycine might therefore be a physiological activator that regulates the proliferation and differentiation of salivary glands.
authors.affiliation: Department of Pediatrics, Kumamoto University, Graduate School of Medical Sciences, Honjo, Kumamoto City, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Shirou
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Taiga
authors.initials: T
authors.lastname: Mochida
authors.forename: Kimitoshi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Kenji
authors.initials: K
authors.lastname: Takehana
authors.forename: Fumio
authors.initials: F
authors.lastname: Endo
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005434:Flow Cytometry; D005998:Glycine / Q000494:pharmacology*; D051379:Mice; D016196:S Phase / Q000187:drug effects; D012469:Salivary Glands / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects*; D013997:Time Factors
chemical_list: D005998:Glycine