title: Stimulation of tissue-type plasminogen activator expression by retinoic acid in human endothelial cells requires retinoic acid receptor beta 2 induction.
abstract: We previously showed the involvement of retinoic acid receptor alpha (RAR alpha) in the induction of tissue-type plasminogen activator (t-PA) synthesis by RA in human umbilical vein endothelial cells (HUVECs). However, the rather slow onset of this induction of t-PA synthesis suggested an indirect role of RAR alpha. Here, we show that the protein synthesis inhibitor, cycloheximide completely blocks the induction of t-PA by RA, which points to the need of an intermediary protein in t-PA stimulation. This intermediary protein is likely to be RAR beta 2 on the basis of the following findings: (1) the induction of RAR beta by RA exactly precedes that of t-PA; (2) HUVECs with elevated RAR beta mRNA levels show an undelayed t-PA induction on stimulation with RA, and this response can be almost completely inhibited with an RAR antagonist; and (3) an antisense oligodeoxynucleotide against the translation initiation site of RAR beta 2 mRNA greatly reduces the t-PA induction by RA. Thus, induction of t-PA by RA in HUVECs involves a 2-step mechanism requiring induction of RAR beta 2 via RAR alpha, followed by induction of t-PA synthesis via RAR beta 2. Each of these steps is shown to have a different activation profile with RA and 9 cis RA.
authors.affiliation: Gaubius Laboratory, Leiden, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Lansink
authors.forename: T
authors.initials: T
authors.lastname: Kooistra
mesh_terms: D001483:Base Sequence; D001565:Benzoates / Q000494:pharmacology; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D018168:Receptors, Retinoic Acid / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D000072482:Retinoic Acid Receptor alpha; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics; D014212:Tretinoin / Q000494:pharmacology*; D014471:Umbilical Veins
chemical_list: D001565:Benzoates; D002839:Chromans; D018076:DNA, Complementary; D016376:Oligonucleotides, Antisense; D011500:Protein Synthesis Inhibitors; C000607071:RARA protein, human; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; C082925:retinoic acid receptor beta; C084904:Ro 41-5253; D014212:Tretinoin; D003513:Cycloheximide; D010959:Tissue Plasminogen Activator