Ca2+/Calmodulin-Dependent Protein Kinase II and Protein Kinase A Differentially Regulate Sarcoplasmic Reticulum Ca2+ Leak in Human Cardiac Pathology
2013 | journal article; research paper. A publication with affiliation to the University of Göttingen.
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Ca2+/Calmodulin-Dependent Protein Kinase II and Protein Kinase A Differentially Regulate Sarcoplasmic Reticulum Ca2+ Leak in Human Cardiac Pathology
Fischer, T. H. ; Herting, J. ; Tirilomis, T. ; Renner, A.; Neef, S.; Toischer, K. & Ellenberger, D. et al. (2013)
Circulation, 128(9) pp. 970-981. DOI: https://doi.org/10.1161/CIRCULATIONAHA.113.001746
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- Authors
- Fischer, Thomas H. ; Herting, Jonas ; Tirilomis, Theodor ; Renner, André; Neef, Stefan; Toischer, Karl ; Ellenberger, David ; Foerster, Anna; Schmitto, Jan D.; Gummert, Jan; Schoendube, Friedrich A. ; Hasenfuß, Gerd ; Maier, Lars S. ; Sossalla, Samuel
- Abstract
- Background Sarcoplasmic reticulum (SR) Ca2+ leak through ryanodine receptor type 2 (RyR2) dysfunction is of major pathophysiological relevance in human heart failure (HF); however, mechanisms underlying progressive RyR2 dysregulation from cardiac hypertrophy to HF are still controversial. Methods and Results We investigated healthy control myocardium (n=5) and myocardium from patients with compensated hypertrophy (n=25) and HF (n=32). In hypertrophy, Ca2+/calmodulin-dependent protein kinase II (CaMKII) and protein kinase A (PKA) both phosphorylated RyR2 at levels that were not different from healthy myocardium. Accordingly, inhibitors of these kinases reduced the SR Ca2+ leak. In HF, however, the SR Ca2+ leak was nearly doubled compared with hypertrophy, which led to reduced systolic Ca2+ transients, a depletion of SR Ca2+ storage and elevated diastolic Ca2+ levels. This was accompanied by a significantly increased CaMKII-dependent phosphorylation of RyR2. In contrast, PKA-dependent RyR2 phosphorylation was not increased in HF and was independent of previous -blocker treatment. In HF, CaMKII inhibition but not inhibition of PKA yielded a reduction of the SR Ca2+ leak. Moreover, PKA inhibition further reduced SR Ca2+ load and systolic Ca2+ transients. Conclusions In human hypertrophy, both CaMKII and PKA functionally regulate RyR2 and may induce SR Ca2+ leak. In the transition from hypertrophy to HF, the diastolic Ca2+ leak increases and disturbed Ca2+ cycling occurs. This is associated with an increase in CaMKII- but not PKA-dependent RyR2 phosphorylation. CaMKII inhibition may thus reflect a promising therapeutic target for the treatment of arrhythmias and contractile dysfunction.
- Issue Date
- 2013
- Journal
- Circulation
- Project
- SFB 1002: Modulatorische Einheiten bei Herzinsuffizienz
SFB 1002 | A03: Bedeutung CaMKII-abhängiger Mechanismen für die Arrhythmogenese bei Herzinsuffizienz
SFB 1002 | D01: Erholung aus der Herzinsuffizienz – Einfluss von Fibrose und Transkriptionssignatur - Working Group
- RG Hasenfuß (Transition zur Herzinsuffizienz)
RG L. Maier (Experimentelle Kardiologie)
RG Sossalla (Kardiovaskuläre experimentelle Elektrophysiologie und Bildgebung)
RG T. Fischer
RG Toischer (Kardiales Remodeling) - ISSN
- 0009-7322