Myofilament carbonylation modulates contractility in human cardiomyocytes

Ágnes Balogh, Attila Tot́h, Eniko Tot́h Pásztorńe, Lászĺo Nagy, Árṕad Kov́acs, Judit Kalaśz, Gerardo Alvarado Contreras, István Édes, Zolt́an Papp

Research output: Contribution to journalArticlepeer-review

Abstract

This study investigated the effects of myofilament carbonylation in permeabilized human left ventricular cardiomyocytes. Protein carbonylation was monitored by the oxyblot method following the in vitro application of the Fenton reaction reagents [iron(II), ascorbic acid and hydrogen peroxide (H 2O2)], known to produce hydroxyl radicals. Sulfhydryl group oxidation was assessed in parallel by the Ellman assay. During force measurements, the Ca2+-activated active force, the Ca 2+-independent passive force and the Ca2+ sensitivity of force production (pCa50) were measured in permeabilized cardiomyocytes before and after in vitro carbonylation. Carbonylation at the levels of several myofilament proteins (e.g. myosin heavy chain, α-actinin, actin, myosin binding protein C, desmin and myosin light chain 1) was enhanced by increasing concentrations of H2O2 (0-105 μM) in the Fenton solution. Carbonylation suspended active force generation following aggressive Fenton treatment (105 μM H2O2), whereas the application of 3*103 μM H2O2 decreased pCa50 (from 5.74±0.01 to 5.65±0.01; mean±SEM, P<0.05) and increased the passive force (from 1.72±0.21 kN/m2 to 2.33±0.22 kN/m2). None of these changes was influenced by sulfhydryl group reduction. Thus, myofilament carbonylation dysregulates the contractile function in human cardiomyocytes, and may therefore mediate the contractile dysfunction during oxidative stress.

Original languageEnglish (US)
Pages (from-to)2026-2035
Number of pages10
JournalExperimental and Clinical Cardiology
Volume20
Issue number1
StatePublished - 2014

Keywords

  • Carbonylation
  • Contractile function
  • Isolated human cardiomyocytes
  • Oxidative stress

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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