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Inactivation of peroxisome proliferator-activated receptor isoforms α, β/δ, and γ mediate distinct facets of hypertrophic transformation of adult cardiac myocytes

Pellieux, Corinne ; Montessuit, Christophe ; Papageorgiou, Irène ; Lerch, René

In: Pflügers Archiv - European Journal of Physiology, 2007, vol. 455, no. 3, p. 443-454

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    Title
    • Inactivation of peroxisome proliferator-activated receptor isoforms α, β/δ, and γ mediate distinct facets of hypertrophic transformation of adult cardiac myocytes
    Author
    • Pellieux, Corinne. Department of Internal Medicine, Cardiology Center, University Hospitals of Geneva, 24, rue Micheli-du-Crest, CH-1211, 14, Geneva, Switzerland
    • Montessuit, Christophe. Department of Internal Medicine, Cardiology Center, University Hospitals of Geneva, 24, rue Micheli-du-Crest, CH-1211, 14, Geneva, Switzerland
    • Papageorgiou, Irène. Department of Internal Medicine, Cardiology Center, University Hospitals of Geneva, 24, rue Micheli-du-Crest, CH-1211, 14, Geneva, Switzerland
    • Lerch, René. Department of Internal Medicine, Cardiology Center, University Hospitals of Geneva, 24, rue Micheli-du-Crest, CH-1211, 14, Geneva, Switzerland
    Document Type
    • Postprint
    Language
    • English
    Published in
    • Pflügers Archiv - European Journal of Physiology, 2007, vol. 455, no. 3, p. 443-454. Springer-Verlag
    Other Version
    OAI-PMH Identifier
    • oai:doc.rero.ch:319846
    Summary
    Inactivation of peroxisome proliferator-activated receptor (PPARs) isoforms α, β/δ, and γ mediate distinct facets of hypertrophic transformation of adult cardiac myocytes. PPARs are ligand-activated transcription factors that modulate the transcriptional regulation of fatty acid metabolism and the hypertrophic response in neonatal cardiac myocytes. The purpose of this study was to determine the role of PPAR isoforms in the morphologic and metabolic phenotype transformation of adult cardiac myocytes in culture, which, in medium containing 20% fetal calf serum, undergo hypertrophy-like cell growth associated with downregulation of regulatory proteins of fatty acid metabolism. Expression and DNA-binding activity of PPARα, PPARβ/δ, and PPARγ rapidly decreased after cell isolation and remained persistently reduced during the 14-day culture period. Cells progressively increased in size and developed both re-expression of atrial natriuretic factor and downregulation of regulatory proteins of fatty acid metabolism. Supplementation of the medium with fatty acid (oleate 0.25mM/palmitate 0.25mM) prevented inactivation of PPARs and downregulation of metabolic genes. Furthermore, cell size and markers of hypertrophy were markedly reduced. Selective activation of either PPARα or PPARβ/δ completely restored expression of regulatory genes of fatty acid metabolism but did not influence cardiac myocyte size and markers of hypertrophy. Conversely, activation of PPARγ prevented cardiomyocyte hypertrophy but had no effect on fatty acid metabolism. The results indicate that PPAR activity markedly influences hypertrophic transformation of adult rat cardiac myocytes. Inactivation of PPARα and PPARβ/δ accounts for downregulation of the fatty acid oxidation pathway, whereas inactivation of PPARγ enables development of hypertrophy