Kotaro Horiguchi

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The anterior pituitary gland is composed of five types of hormone-producing cells plus folliculostellate (FS) cells, which do not produce classical anterior pituitary hormones. FS cells are interconnected by cytoplasmic processes and encircle hormone-producing cells or aggregate homophilically. Using living-cell imaging of primary culture, we recently(More)
Retinoic acid (RA) plays a critical role in embryonic development, growth, and reproduction. RA is synthesized from retinoids via oxidation processes, and the oxidation of retinal to RA is catalyzed by the retinaldehyde dehydrogenases (RALDHs). We previously reported that RALDH1 mRNA was expressed in the anterior pituitary glands of adult rats and(More)
Folliculo-stellate (FS) cells in the anterior pituitary gland appear to possess multifunctional properties. Recently, the development of transgenic rats (S100b-green fluorescent protein (GFP) rats) that express GFP specifically in FS cells in the anterior pituitary gland has allowed us to distinguish and observe living FS cells in other kinds of pituitary(More)
Proteoglycans are components of the extracellular matrix and comprise a specific core protein substituted with covalently linked glycosaminoglycan chains. Small leucine-rich proteoglycans (SLRPs) are a major family of proteoglycans and have key roles as potent effectors in cellular signaling pathways. Research during the last two decades has shown that(More)
Gene expressions and their interaction are complex and have not been definitely clarified in the placenta. To identify interactions of gene products previously not studied, we applied cDNA subtraction analyses to the placenta between days 12 and 16, days 12 and 14, days 14 and 16 of pregnancy. Among subtracted cDNAs cathepsin M, Q and R in PECs were(More)
Phosphorylated prolactin (PPRL) is considered to be the most quantitatively important post-translationally modified form of prolactin (PRL) in rodents. We recently detected two different types of PPRL in the mouse pituitary gland; one was phosphorylated at serine and the other was phosphorylated at serine/threonine. Furthermore, we showed that there are(More)
Cadherins are a family of transmembrane glycoproteins that mediate cell-to-cell adhesion. A change in cadherin type in cells, i.e., cadherin switching, induces changes in the character of the cell. Recent studies of the developing rat adenohypophysis found that primordial cells co-expressed E- and N-cadherins, but that hormone-producing cells lost(More)
Folliculostellate (FS) cells in the anterior pituitary gland are believed to have multifunctional properties. Using transgenic rats that express green fluorescent protein (GFP) specifically in FS cells in the anterior pituitary gland (S100b-GFP rats), we recently revealed that FS cells in primary culture exhibited marked proliferation in the presence of(More)
S100β-protein-positive cells in the anterior pituitary gland appear to possess multifunctional properties. Because of their pleiotropic features, S100β-positive cells are assumed to be of a heterogeneous or even a non-pituitary origin. The observation of various markers has allowed these cells to be classified into populations such as stem/progenitor cells,(More)
Folliculo-stellate (FS) cells in the anterior pituitary gland are believed to have multifunctional properties. FS cells connect to each other not only by mechanical means, but also by gap junctional cell-to-cell communication. Using transgenic rats that express green fluorescent protein (GFP) specifically in FS cells in the anterior pituitary gland(More)