title: Activated p300 acetyltransferase activity modulates aortic valvular calcification with osteogenic transdifferentiation and downregulation of Klotho.
abstract: BACKGROUND
  The calcific aortic valve (AV) disease is a common disease with the unclear mechanism, and optimal pharmacological treatment remains unavailable. Epigenetic modulation by histone acetyltransferase (HAT) plays a critical role in osteogenic transdifferentiation and atherosclerosis. The purposes of this study were to investigate whether HAT contributes to the pathophysiology of AV calcification and assess the therapeutic potential of HAT inhibition.
  
  
  METHODS
  Porcine valvular interstitial cells (VICs) were treated with osteogenic medium (10ng/mL of tumor necrosis factor-α and 4mmol/L of high phosphate) for 7days. We analyzed the RNA and protein expression of myofibroblastic (α-SMA, vimentin, collagen 1A1, collagen 3, Egr-1, MMP2, MMP9) and osteoblastic markers (osteocalcin and alkaline phosphatase) in VICs, and studied the effects of a p300 inhibitor (C646, 10μmol/L) on calcification (Alizarin Red S staining), osteogenesis, HAT activity, the mitogen-activated protein kinase (MAPK) and Akt pathway, and Klotho expression on VICs.
  
  
  RESULTS
  Osteogenic medium treated VICs had higher expressions of osteocalcin, alkaline phosphatase and acetylated lysine-9 of histone H3 (ac-H3K9) than control cells. C646 attenuated osteogenesis of VICs with simultaneous inhibition of the HAT activity of p300. There was neither significant increase of p300 protein nor p300 transcript during the osteogenesis process. Additionally, osteogenic medium treated VICs decreased the expression of Klotho, which is attenuated by C646.
  
  
  CONCLUSIONS
  Activated HAT activity of p300 modulates AV calcification through osteogenic transdifferentiation of VICs with Klotho modulation. P300 inhibition is a potential therapeutic target for AV calcification.
authors.affiliation: Grarduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Cardiovascular Surgery, Department of Surgery, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shao-Jung
authors.initials: SJ
authors.lastname: Li
authors.affiliation: Grarduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan. Electronic address: yuhsunkao@gmail.com.
authors.forename: Yu-Hsun
authors.initials: YH
authors.lastname: Kao
authors.affiliation: Grarduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Cheng-Chih
authors.initials: CC
authors.lastname: Chung
authors.affiliation: Department of Pathology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pathology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Chen
authors.affiliation: Grarduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Wan-Li
authors.initials: WL
authors.lastname: Cheng
authors.affiliation: Grarduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan. Electronic address: a9900112@ms15.hinet.net.
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D000368:Aged; D000818:Animals; D001021:Aortic Valve / Q000378:metabolism / Q000473:pathology*; D001024:Aortic Valve Stenosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D002114:Calcinosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation; D002478:Cells, Cultured; D004195:Disease Models, Animal; D015536:Down-Regulation; D005260:Female; D005786:Gene Expression Regulation; D005966:Glucuronidase / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D000090265:Klotho Proteins; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics*; D015398:Signal Transduction; D013552:Swine; D050880:p300-CBP Transcription Factors / Q000378:metabolism*; D000099224:p300-CBP-Associated Factor
chemical_list: D005966:Glucuronidase; D000090265:Klotho Proteins; D012313:RNA; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
keywords: Aortic valve calcification; Klotho; Osteogenesis; P300; Valvular interstitial cells