PMID- 30770570 OWN - NLM STAT- MEDLINE DCOM- 20210215 LR - 20220531 IS - 1469-7793 (Electronic) IS - 0022-3751 (Linking) VI - 598 IP - 7 DP - 2020 Apr TI - CaMKII does not control mitochondrial Ca(2+) uptake in cardiac myocytes. PG - 1361-1376 LID - 10.1113/JP276766 [doi] AB - KEY POINTS: Mitochondrial Ca(2+) uptake stimulates the Krebs cycle to regenerate the reduced forms of pyridine nucleotides (NADH, NADPH and FADH(2) ) required for ATP production and reactive oxygen species (ROS) elimination. Ca(2+) /calmodulin-dependent protein kinase II (CaMKII) has been proposed to regulate mitochondrial Ca(2+) uptake via mitochondrial Ca(2+) uniporter phosphorylation. We used two mouse models with either global deletion of CaMKIIdelta (CaMKIIdelta knockout) or cardiomyocyte-specific deletion of CaMKIIdelta and gamma (CaMKIIdelta/gamma double knockout) to interrogate whether CaMKII controls mitochondrial Ca(2+) uptake in isolated mitochondria and during beta-adrenergic stimulation in cardiac myocytes. CaMKIIdelta/gamma did not control Ca(2+) uptake, respiration or ROS emission in isolated cardiac mitochondria, nor in isolated cardiac myocytes, during beta-adrenergic stimulation and pacing. The results of the present study do not support a relevant role of CaMKII for mitochondrial Ca(2+) uptake in cardiac myocytes under physiological conditions. ABSTRACT: Mitochondria are the main source of ATP and reactive oxygen species (ROS) in cardiac myocytes. Furthermore, activation of the mitochondrial permeability transition pore (mPTP) induces programmed cell death. These processes are essentially controlled by Ca(2+) , which is taken up into mitochondria via the mitochondrial Ca(2+) uniporter (MCU). It was recently proposed that Ca(2+) /calmodulin-dependent protein kinase II (CaMKII) regulates Ca(2+) uptake by interacting with the MCU, thereby affecting mPTP activation and programmed cell death. In the present study, we investigated the role of CaMKII under physiological conditions in which mitochondrial Ca(2+) uptake matches energy supply to the demand of cardiac myocytes. Accordingly, we measured mitochondrial Ca(2+) uptake in isolated mitochondria and cardiac myocytes harvested from cardiomyocyte-specific CaMKII delta and gamma double knockout (KO) (CaMKIIdelta/gamma DKO) and global CaMKIIdelta KO mice. To simulate a physiological workload increase, cardiac myocytes were subjected to beta-adrenergic stimulation (by isoproterenol superfusion) and an increase in stimulation frequency (from 0.5 to 5 Hz). No differences in mitochondrial Ca(2+) accumulation were detected in isolated mitochondria or cardiac myocytes from both CaMKII KO models compared to wild-type littermates. Mitochondrial redox state and ROS production were unchanged in CaMKIIdelta/gamma DKO, whereas we observed a mild oxidation of mitochondrial redox state and an increase in H(2) O(2) emission from CaMKIIdelta KO cardiac myocytes exposed to an increase in workload. In conclusion, the results obtained in the present study do not support the regulation of mitochondrial Ca(2+) uptake via the MCU or mPTP activation by CaMKII in cardiac myocytes under physiological conditions. CI - (c) 2019 The Authors. The Journal of Physiology (c) 2019 The Physiological Society. FAU - Nickel, Alexander G AU - Nickel AG AD - Comprehensive Heart Failure Center (CHFC), University Clinic Wurzburg, Wurzburg, Germany. AD - Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany. FAU - Kohlhaas, Michael AU - Kohlhaas M AD - Comprehensive Heart Failure Center (CHFC), University Clinic Wurzburg, Wurzburg, Germany. AD - Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany. FAU - Bertero, Edoardo AU - Bertero E AD - Comprehensive Heart Failure Center (CHFC), University Clinic Wurzburg, Wurzburg, Germany. FAU - Wilhelm, Daniel AU - Wilhelm D AUID- ORCID: 0000-0002-0386-6702 AD - Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany. FAU - Wagner, Michael AU - Wagner M AD - Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany. AD - Institute for Molecular Cell Biology, Saarland University, Homburg, Germany. FAU - Sequeira, Vasco AU - Sequeira V AD - Comprehensive Heart Failure Center (CHFC), University Clinic Wurzburg, Wurzburg, Germany. FAU - Kreusser, Michael M AU - Kreusser MM AD - Institute of Experimental Cardiology, Heidelberg University Hospital, Heidelberg, Germany. AD - German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, Germany. AD - Department of Cardiology, Heidelberg University Hospital, Heidelberg, Germany. FAU - Dewenter, Matthias AU - Dewenter M AD - Institute of Experimental Cardiology, Heidelberg University Hospital, Heidelberg, Germany. AD - German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, Germany. FAU - Kappl, Reinhard AU - Kappl R AD - Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany. FAU - Hoth, Markus AU - Hoth M AUID- ORCID: 0000-0001-7080-4643 AD - Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany. FAU - Dudek, Jan AU - Dudek J AD - Comprehensive Heart Failure Center (CHFC), University Clinic Wurzburg, Wurzburg, Germany. FAU - Backs, Johannes AU - Backs J AD - Institute of Experimental Cardiology, Heidelberg University Hospital, Heidelberg, Germany. AD - German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, Germany. FAU - Maack, Christoph AU - Maack C AUID- ORCID: 0000-0002-2742-5426 AD - Comprehensive Heart Failure Center (CHFC), University Clinic Wurzburg, Wurzburg, Germany. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20190327 PL - England TA - J Physiol JT - The Journal of physiology JID - 0266262 RN - 0 (Reactive Oxygen Species) RN - EC 2.7.11.17 (Calcium-Calmodulin-Dependent Protein Kinase Type 2) RN - SY7Q814VUP (Calcium) SB - IM MH - Animals MH - Calcium MH - *Calcium-Calmodulin-Dependent Protein Kinase Type 2 MH - Mice MH - *Myocytes, Cardiac MH - Reactive Oxygen Species MH - Sarcoplasmic Reticulum OTO - NOTNLM OT - CaMKII OT - mitochondrial Ca2+ uptake OT - reactive oxygen species EDAT- 2019/02/17 06:00 MHDA- 2021/02/16 06:00 CRDT- 2019/02/17 06:00 PHST- 2018/08/01 00:00 [received] PHST- 2019/02/13 00:00 [accepted] PHST- 2019/02/17 06:00 [pubmed] PHST- 2021/02/16 06:00 [medline] PHST- 2019/02/17 06:00 [entrez] AID - 10.1113/JP276766 [doi] PST - ppublish SO - J Physiol. 2020 Apr;598(7):1361-1376. doi: 10.1113/JP276766. Epub 2019 Mar 27.