title: Matrix metalloproteinase-9 expression in folliculostellate cells of rat anterior pituitary gland.
abstract: Folliculostellate (FS) cells of the anterior pituitary gland express a variety of regulatory molecules. Using transgenic rats that express green fluorescent protein specifically in FS cells, we recently demonstrated that FS cells in vitro showed marked changes in motility, proliferation, and that formation of cellular interconnections in the presence of laminin, a component of the extracellular matrix, closely resembled those observed in vivo. These findings suggested that FS cells express matrix metalloproteinase-9 (MMP-9), which assists their function on laminin. In the present study, we investigate MMP-9 expression in rat anterior pituitary gland and examine its role in motility and proliferation of FS cells on laminin. Immunohistochemistry, RT-PCR, immunoblotting, and gelatin zymography were performed to assess MMP-9 expression in the anterior pituitary gland and cultured FS cells. Real-time RT-PCR was used to quantify MMP-9 expression in cultured FS cells under different conditions and treatments. MMP-9 expression was inhibited by pharmacological inhibitor or downregulated by siRNA and time-lapse images were acquired. A 5-bromo-2'-deoxyuridine assay was performed to analyze the proliferation of FS cells. Our results showed that MMP-9 was expressed in FS cells, that this expression was upregulated by laminin, and that laminin induced MMP-9 secretion by FS cells. MMP-9 inhibition and downregulation did not impair FS motility; however, it did impair the capacity of FS cells to form interconnections and it significantly inhibited proliferation of FS cells on laminin. We conclude that MMP-9 is necessary in FS cell interconnection and proliferation in the presence of laminin.
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan. d1030@jichi.ac.jp
authors.forename: Cimi
authors.initials: C
authors.lastname: Ilmiawati
authors.forename: Kotaro
authors.initials: K
authors.lastname: Horiguchi
authors.forename: Ken
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Takashi
authors.initials: T
authors.lastname: Yashiro
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002450:Cell Communication / Q000502:physiology; D049109:Cell Proliferation; D002478:Cells, Cultured; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D007797:Laminin / Q000502:physiology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D009414:Nerve Growth Factors / Q000235:genetics; D010903:Pituitary Gland, Anterior / Q000166:cytology* / Q000201:enzymology*; D051381:Rats; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000235:genetics
chemical_list: D007797:Laminin; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D049452:Green Fluorescent Proteins; D020780:Matrix Metalloproteinase 9