title: Effect of retinoic acid on midkine gene expression in rat anterior pituitary cells.
abstract: Retinoic acid (RA) is converted from retinal by retinaldehyde dehydrogenases (RALDHs) and is an essential signaling molecule in embryonic and adult tissue. We previously reported that RALDH1 was produced in the rat anterior pituitary gland and hypothesized that RA was generated in the gland. Midkine (MK) is an RA-inducible growth factor, and MK production in the rat anterior pituitary gland was recently reported. However, the mechanism that regulates gene expression of MK in the pituitary gland has not been determined. To investigate regulation of MK production in the anterior pituitary gland, we analyzed changes in MK mRNA in cultured rat anterior pituitary cells. We identified MK-expressing cells by double-staining with in situ hybridization and immunohistochemical techniques for RALDH1. MK mRNA was expressed in RALDH1-producing cells in the anterior pituitary gland. Using isolated anterior pituitary cells of rats, we examined the effect of RA on gene expression of MK. Quantitative real-time PCR revealed that 72 h exposure to a concentration of 10-6M of retinal and all-trans retinoic acid increased MK mRNA levels by about 2-fold. Moreover, the stimulatory effect of all-trans retinoic acid was mimicked by the RA receptor agonist Am80. This is the first report to show that RA is important in regulating MK expression in rat anterior pituitary gland.
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan.
authors.forename: Rita
authors.initials: R
authors.lastname: Maliza
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Fujiwara
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Azuma
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan.|Laboratory of Natural History, Jichi Medical University School of Medicine, Tochigi, Japan.
authors.forename: Motoshi
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yashiro
mesh_terms: D015081:2-Naphthylamine / Q000031:analogs & derivatives / Q000494:pharmacology; D000080924:Aldehyde Dehydrogenase 1 Family; D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D036341:Intercellular Signaling Peptides and Proteins / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008297:Male; D000078792:Midkine; D009414:Nerve Growth Factors / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011743:Pyrimidines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D018168:Receptors, Retinoic Acid / Q000819:agonists / Q000378:metabolism; D050697:Retinal Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D012172:Retinaldehyde / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D014212:Tretinoin / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D001565:Benzoates; D036341:Intercellular Signaling Peptides and Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; C000608768:PA024 compound; D011743:Pyrimidines; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D013764:Tetrahydronaphthalenes; C061133:tamibarotene; D000078792:Midkine; D014212:Tretinoin; D015081:2-Naphthylamine; D000080924:Aldehyde Dehydrogenase 1 Family; C523119:Aldh1a1 protein, rat; D050697:Retinal Dehydrogenase; D012172:Retinaldehyde
keywords: Anterior pituitary gland; Midkine; Retinaldehyde dehydrogenase; Retinoic acid; Retinoic acid receptor