title: Regulation of intercellular adhesion molecule-1 expression by retinoic acid: analysis of the 5' regulatory region of the gene.
abstract: Human intercellular adhesion molecule-1 (ICAM-1), a specific ligand for the lymphocyte-function-associated antigen-1, plays an important role in immune responses. ICAM-1 expression is regulated by various proinflammatory cytokines, by PMA, and by retinoic acid. In this study, we have investigated the mechanisms of transcriptional control involved in the stimulation of ICAM-1 gene expression by retinoic acid in SK-N-SH cells. Northern-blot analysis demonstrated that ICAM-1 mRNA is maximally induced at 24 hr, suggesting that it is not an early-response gene with respect to retinoic-acid responsiveness, whereas the retinoic acid receptor-beta mRNA level was maximal 12 hr following retinoic acid treatment. To analyze the 5'-regulatory region of the ICAM-1 gene, an EcoRI/SaII fragment spanning the first 1.3 kb upstream of the translational start site was used to direct the expression of a linked luciferase reporter gene in transient transfection assays in SK-N-SH cells. A 24-hr treatment of transfected cells with 10 microM retinoic acid resulted in a 10- to 13-fold increase in luciferase activity compared with untreated cells. Deletion mutant analysis revealed that a region located between -393 and -176 bp from the translational start site is critical for retinoic acid stimulation of luciferase activity. This region harbors a consensus sequence for a retinoic-acid-responsive element (RARE) homologous to the element found upstream of the alcohol dehydrogenase-3 gene. Co-transfection of expression vectors encoding the retinoic acid receptor-alpha, -beta, or -gamma, with reporter plasmids harboring the putative RARE, confirmed that the ICAM-1 gene is regulated by retinoic acid in a retinoic acid receptor-dependent fashion.
authors.affiliation: Laboratory of Molecular Endocrinology, CHUL Research Center, Quebec, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Aoudjit
authors.forename: M
authors.initials: M
authors.lastname: Bossé
authors.forename: C
authors.initials: C
authors.lastname: Stratowa
authors.forename: G
authors.initials: G
authors.lastname: Voraberger
authors.forename: M
authors.initials: M
authors.lastname: Audette
mesh_terms: D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D016384:Consensus Sequence; D004252:DNA Mutational Analysis; D005786:Gene Expression Regulation; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D015815:Cell Adhesion Molecules; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta; D018799:Intercellular Adhesion Molecule-1; D014212:Tretinoin