title: Retinoic acid enhances connexin43 expression at the post-transcriptional level in rat liver epithelial cells.
abstract: The mechanism by which all-trans retinoic acid (RA) stimulates gap junctional intercellular communication (GJIC) in the rat liver epithelial cell line. IAR203, was investigated. When RA, at 0.1 microM for 24-48 h, enhanced the dye transfer in IAR203 cells (x 1.4), it increased the amount of connexin43 (Cx43) in the cell-cell contact regions of the plasma membrane, as evidenced by analysis by Western blot and by immunofluorescence. It had no effect on the level of Cx43 mRNA. Freeze-fracture analysis of the size of gap junctions revealed an increase of the proportion of small gap junctions in RA-treated cells. We conclude that, in IAR203 cells, RA stimulates GJIC by acting at the post-transcriptional level of Cx43 regulation. The possibility that RA acts indirectly on the regulation of Cx43 expression, and increases the half-life of Cx43 by inducing adhesion molecules is discussed.
authors.affiliation: Institut National de la Recherche Agronomique, Laboratoire de Nutrition et Sécurité Alimentaire, Jouy-en-Josas, France.
authors.forename: V
authors.initials: V
authors.lastname: Bex
authors.forename: T
authors.initials: T
authors.lastname: Mercier
authors.forename: C
authors.initials: C
authors.lastname: Chaumontet
authors.forename: I
authors.initials: I
authors.lastname: Gaillard-Sanchez
authors.forename: B
authors.initials: B
authors.lastname: Flechon
authors.forename: F
authors.initials: F
authors.lastname: Mazet
authors.forename: O
authors.initials: O
authors.lastname: Traub
authors.forename: P
authors.initials: P
authors.lastname: Martel
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D015153:Blotting, Western; D002460:Cell Line; D004396:Coloring Agents; D018031:Connexin 43 / Q000096:biosynthesis*; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005614:Freeze Fracturing; D017629:Gap Junctions / Q000187:drug effects; D006207:Half-Life; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D004396:Coloring Agents; D018031:Connexin 43; D012333:RNA, Messenger; D014212:Tretinoin