title: Epigenetic control of tissue-type plasminogen activator synthesis in human endothelial cells.
abstract: OBJECTIVE
  Tissue-type plasminogen activator (t-PA) is produced by endothelial cells (EC) and is responsible for the removal of intravascular fibrin deposits. We investigated whether expression of t-PA by EC is under epigenetic control.
  
  
  RESULTS
  Methylation analysis of the proximal t-PA promoter revealed a stretch of unmethylated CpG dinucleotides from position -121 to +59, while upstream CpG dinucleotides were all methylated. In contrast, in human primary hepatocytes, which express t-PA at much lower levels than EC, the proximal promoter was partially methylated. Treatment of EC with the non-specific histone deacetylase (HDAC) inhibitors butyrate and trichostatin and with MS275, a specific inhibitor of class I HDAC, resulted in a time- and dose-dependent increase in t-PA expression. Garcinol and anacardic acid, inhibitors of the histone acetyl transferases CBP/p300 and PCAF, reduced basal and HDAC inhibitor-induced t-PA expression, whereas curcumin, an inhibitor of CBP/p300 only, had no effect. We performed chromosome immunoprecipitation analysis of the t-PA promoter using antibodies specific for acetylated histone H3 or H4 and observed an increase in H3 acetylation of 10 ± 3 and 44 ± 14-fold in EC treated with trichostatin or MS275, respectively, and in H4 acetylation of 7.7 ± 1.4 and 16 ± 3-fold, respectively.
  
  
  CONCLUSIONS
  The proximal t-PA promoter is unmethylated in human EC and partially methylated in human primary hepatocytes. Expression of t-PA by EC is repressed by HDACs in a mechanism that involves de-acetylation of histone H3 and H4.
authors.affiliation: Division of Angiology and Hemostasis, University Hospital of Geneva, University Medical Center, Room 9094, Rue Michel Servet 1, CH-1211, Geneva, Switzerland.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dunoyer-Geindre
authors.forename: Egbert K O
authors.initials: EK
authors.lastname: Kruithof
mesh_terms: D001483:Base Sequence; D002478:Cells, Cultured; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D044127:Epigenesis, Genetic / Q000187:drug effects; D022781:Hepatocytes / Q000378:metabolism; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006655:Histone Deacetylases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D017931:DNA Primers; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D012333:RNA, Messenger; D010959:Tissue Plasminogen Activator; D006655:Histone Deacetylases