101. Activated p300 acetyltransferase activity modulates aortic valvular calcification with osteogenic transdifferentiation and downregulation of Klotho.
- Author
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Li SJ, Kao YH, Chung CC, Chen WY, Cheng WL, and Chen YJ
- Subjects
- Aged, Animals, Aortic Valve metabolism, Aortic Valve Stenosis metabolism, Aortic Valve Stenosis pathology, Blotting, Western, Calcinosis metabolism, Calcinosis pathology, Cell Differentiation, Cells, Cultured, Disease Models, Animal, Down-Regulation, Female, Glucuronidase biosynthesis, Humans, Klotho Proteins, Male, Middle Aged, Polymerase Chain Reaction, Signal Transduction, Swine, Aortic Valve pathology, Aortic Valve Stenosis genetics, Calcinosis genetics, Gene Expression Regulation, Glucuronidase genetics, Osteogenesis genetics, RNA genetics, p300-CBP Transcription Factors metabolism
- 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., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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