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001-es BibID:	BIBFORM049848
Első szerző:	Balogh Ágnes (kardiológus)
Cím:	Myofilament carbonylation modulates contractility in human cardiomyocytes / Ágnes Balogh, Attila Tóth, Enikő Pásztorné Tóth, László Nagy, Árpád Kovács, Judit Kalász, Gerardo Alvarado Contreras, István Édes, Zoltán Papp
Dátum:	2014
Megjegyzések:	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 (H2O2)], 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 Ca2+-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, ?-actinin, actin, myosin binding protein C, desmin and myosin light chain 1) was enhanced by increasing concentrations of H2O2 (0-105 ?M) in the Fenton solution. Carbonylation suspended active force generation following aggressive Fenton treatment (105 ?M H2O2), whereas the application of 3*103 ?M 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.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Experimental & Clinical Cardiology 20 : 1 (2014), p. 2026-2035. -
További szerzők:	Tóth Attila (1971-) (biológus) Pásztorné Tóth Enikő (1966-) (laboratóriumi analitikus) Nagy László (1988-) (orvos) Kovács Árpád (1986-) (kardiológus) Kalász Judit (1986-) (molekuláris biológus) Contreras, Gerardo Alvarado (1978-) (orvos) Édes István (1952-) (kardiológus) Papp Zoltán (1965-) (kardiológus, élettanász)
Pályázati támogatás:	TÁMOP-4.2.2.A-11/1/KONV-2012-0045 TÁMOP Kardiológia Kutatócsoport K 109083 OTKA HEALTH-2010: "MEDIA-Metabolic Road to Diastolic Heart Failure" MEDIA-261409 FP7 TÁMOP 4.2.4. A/2-11-1-2012-0001 TÁMOP
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM068537
Első szerző:	Kovács Árpád (kardiológus)
Cím:	Myosin heavy chain and cardiac troponin T damage is associated with impaired myofibrillar ATPase activity contributing to sarcomeric dysfunction in Ca2+-paradox rat hearts / Árpád Kovács, Judit Kalász, Enikő T. Pásztor, Attila Tóth, Zoltán Papp, Naranjan S. Dhalla, Judit Barta
Dátum:	2017
ISSN:	0300-8177
Megjegyzések:	This study aimed to explore the potential contribution of myofibrils to contractile dysfunction in Ca2+-paradox hearts. Isolated rat hearts were perfused with Krebs?Henseleit solution (Control), followed by Ca2+-depletion, and then Ca2+-repletion after Ca2+-depletion (Ca2+-paradox) by Langendorff method. During heart perfusion left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of pressure development (+?dP/dt), and pressure decay (-dP/dt) were registered. Control LVDP (127.4???6.1 mmHg) was reduced during Ca2+-depletion (9.8???1.3 mmHg) and Ca2+-paradox (12.9???1.3 mmHg) with similar decline in +dP/dt and ?dP/dt. LVEDP was increased in both Ca2+-depletion and Ca2+-paradox. Compared to Control, myofibrillar Ca2+-stimulated ATPase activity was decreased in the Ca2+-depletion group (12.08???0.57 vs. 8.13???0.19 ?mol Pi/mg protein/h), besides unvarying Mg2+ ATPase activity, while upon Ca2+-paradox myofibrillar Ca2+-stimulated ATPase activity was decreased (12.08???0.57 vs. 8.40???0.22 ?mol Pi/mg protein/h), but Mg2+ ATPase activity was increased (3.20???0.25 vs. 7.21???0.36 ?mol Pi/mg protein/h). In force measurements of isolated cardiomyocytes at saturating [Ca2+], Ca2+-depleted cells had lower rate constant of force redevelopment (ktr,max, 3.85???0.21) and unchanged active tension, while those in Ca2+-paradox produced lower active tension (12.12???3.19 kN/m2) and ktr,max (3.21???23) than cells of Control group (25.07???3.51 and 4.61???22 kN/m2, respectively). In biochemical assays, ?-myosin heavy chain and cardiac troponin T presented progressive degradation during Ca2+-depletion and Ca2+-paradox. Our results suggest that contractile impairment in Ca2+-paradox partially resides in deranged sarcomeric function and compromised myofibrillar ATPase activity as a result of myofilament protein degradation, such as ?-myosin heavy chain and cardiac troponin T. Impaired relaxation seen in Ca2+-paradoxical hearts is apparently not related to titin, rather explained by the altered myofibrillar ATPase activity.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Calcium paradox Myofibrillar ATPase activity Isolated cardiomyocytes Myofilament protein degradation
Megjelenés:	Molecular and Cellular Biochemistry 403 : 1-2 (2017), p. 57-68. -
További szerzők:	Kalász Judit (1986-) (molekuláris biológus) Pásztorné Tóth Enikő (1966-) (laboratóriumi analitikus) Tóth Attila (1971-) (biológus) Papp Zoltán (1965-) (kardiológus, élettanász) Dhalla, Naranjan S. Barta Judit (1975-) (kardiológus)
Pályázati támogatás:	GINOP-2.3.2-15-2016-00043 GINOP K116940 OTKA K109083 OTKA
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