1
|
Walweel K, Beard N, van Helden DF, Laver DR. Dantrolene inhibition of ryanodine channels (RyR2) in artificial lipid bilayers depends on FKBP12.6. J Gen Physiol 2023; 155:e202213277. [PMID: 37279522 PMCID: PMC10244881 DOI: 10.1085/jgp.202213277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 03/18/2023] [Accepted: 05/22/2023] [Indexed: 06/08/2023] Open
Abstract
Dantrolene is a neutral hydantoin that is clinically used as a skeletal muscle relaxant to prevent overactivation of the skeletal muscle calcium release channel (RyR1) in response to volatile anesthetics. Dantrolene has aroused considerable recent interest as a lead compound for stabilizing calcium release due to overactive cardiac calcium release channels (RyR2) in heart failure. Previously, we found that dantrolene produces up to a 45% inhibition RyR2 with an IC50 of 160 nM, and that this inhibition requires the physiological association between RyR2 and CaM. In this study, we tested the hypothesis that dantrolene inhibition of RyR2 in the presence of CaM is modulated by RyR2 phosphorylation at S2808 and S2814. Phosphorylation was altered by incubations with either exogenous phosphatase (PP1) or kinases; PKA to phosphorylate S2808 or endogenous CaMKII to phosphorylate S2814. We found that PKA caused selective dissociation of FKBP12.6 from the RyR2 complex and a loss of dantrolene inhibition. Rapamycin-induced FKBP12.6 dissociation from RyR2 also resulted in the loss of dantrolene inhibition. Subsequent incubations of RyR2 with exogenous FKBP12.6 reinstated dantrolene inhibition. These findings indicate that the inhibitory action of dantrolene on RyR2 depends on RyR2 association with FKBP12.6 in addition to CaM as previously found.
Collapse
Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| | - Nicole Beard
- Faculty of Science and Technology, University of Canberra, Bruce, Australia
| | - Dirk F. van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| | - Derek R. Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, Australia
| |
Collapse
|
2
|
Walweel K, Boon AC, See Hoe LE, Obonyo NG, Pedersen SE, Diab SD, Passmore MR, Hyslop K, Colombo SM, Bartnikowski NJ, Bouquet M, Wells MA, Black DM, Pimenta LP, Stevenson AK, Bisht K, Skeggs K, Marshall L, Prabhu A, James LN, Platts DG, Macdonald PS, McGiffin DC, Suen JY, Fraser JF. Brain stem death induces pro-inflammatory cytokine production and cardiac dysfunction in sheep model. Biomed J 2021; 45:776-787. [PMID: 34666219 PMCID: PMC9661508 DOI: 10.1016/j.bj.2021.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/12/2021] [Accepted: 10/07/2021] [Indexed: 11/23/2022] Open
Abstract
Introduction Organs procured following brain stem death (BSD) are the main source of organ grafts for transplantation. However, BSD is associated with inflammatory responses that may damage the organ and affect both the quantity and quality of organs available for transplant. Therefore, we aimed to investigate plasma and bronchoalveolar lavage (BAL) pro-inflammatory cytokine profiles and cardiovascular physiology in a clinically relevant 6-h ovine model of BSD. Methods Twelve healthy female sheep (37–42 Kg) were anaesthetized and mechanically ventilated prior to undergoing BSD induction and then monitored for 6 h. Plasma and BAL endothelin-1 and cytokines (IL-1β, 6, 8 and tumour necrosis factor alpha (TNF-α)) were assessed by ELISA. Differential white blood cell counts were performed. Cardiac function during BSD was also examined using echocardiography, and cardiac biomarkers (A-type natriuretic peptide and troponin I were measured in plasma. Results Plasma concentrations big ET-1, IL-6, IL-8, TNF-α and BAL IL-8 were significantly (p < 0.01) increased over baseline at 6 h post-BSD. Increased numbers of neutrophils were observed in the whole blood (3.1 × 109 cells/L [95% confidence interval (CI) 2.06–4.14] vs. 6 × 109 cells/L [95%CI 3.92–7.97]; p < 0.01) and BAL (4.5 × 109 cells/L [95%CI 0.41–9.41] vs. 26 [95%CI 12.29–39.80]; p = 0.03) after 6 h of BSD induction vs baseline. A significant increase in ANP production (20.28 pM [95%CI 16.18–24.37] vs. 78.68 pM [95%CI 53.16–104.21]; p < 0.0001) and cTnI release (0.039 ng/mL vs. 4.26 [95%CI 2.69–5.83] ng/mL; p < 0.0001), associated with a significant reduction in heart contractile function, were observed between baseline and 6 h. Conclusions BSD induced systemic pro-inflammatory responses, characterized by increased neutrophil infiltration and cytokine production in the circulation and BAL fluid, and associated with reduced heart contractile function in ovine model of BSD.
Collapse
Affiliation(s)
- K Walweel
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.
| | - A C Boon
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - L E See Hoe
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - N G Obonyo
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia; Initiative to Develop African Research Leaders, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - S E Pedersen
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - S D Diab
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - M R Passmore
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - K Hyslop
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - S M Colombo
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia; University of Milan, Italy
| | | | - M Bouquet
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - M A Wells
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia; School of Medical Science, Griffith University, Australia
| | - D M Black
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - L P Pimenta
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - A K Stevenson
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - K Bisht
- Mater Research Institute, University of Queensland, Australia
| | - K Skeggs
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia; Princess Alexandra Hospital, Woolloongabba, Brisbane, Australia
| | - L Marshall
- Princess Alexandra Hospital, Woolloongabba, Brisbane, Australia
| | - A Prabhu
- The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - L N James
- Princess Alexandra Hospital, Woolloongabba, Brisbane, Australia
| | - D G Platts
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - P S Macdonald
- Cardiac Mechanics Research Laboratory, St. Vincent's Hospital and the Victor Chang Cardiac Research Institute, Victoria Street, Darlinghurst, Sydney, Australia
| | - D C McGiffin
- Cardiothoracic Surgery and Transplantation, The Alfred Hospital, Melbourne, Australia
| | - J Y Suen
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.
| | - J F Fraser
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.
| |
Collapse
|
3
|
Walweel K, Skeggs K, Boon AC, See Hoe LE, Bouquet M, Obonyo NG, Pedersen SE, Diab SD, Passmore MR, Hyslop K, Wood ES, Reid J, Colombo SM, Bartnikowski NJ, Wells MA, Black D, Pimenta LP, Stevenson AK, Bisht K, Marshall L, Prabhu DA, James L, Platts DG, Macdonald PS, McGiffin DC, Suen JY, Fraser JF. Endothelin receptor antagonist improves donor lung function in an ex vivo perfusion system. J Biomed Sci 2020; 27:96. [PMID: 33008372 PMCID: PMC7532654 DOI: 10.1186/s12929-020-00690-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/24/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD). METHODS After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema). RESULTS Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin-eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control. CONCLUSIONS These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.
Collapse
Affiliation(s)
- K Walweel
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.
| | - K Skeggs
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.,Princess Alexandra Hospital, Woolloongabba, Brisbane, QLD, 4102, Australia
| | - A C Boon
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - L E See Hoe
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - M Bouquet
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - N G Obonyo
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.,Initiative to Develop African Research Leaders, KEMRI-Wellcome, Trust Research Programme, Kilifi, Kenya
| | - S E Pedersen
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - S D Diab
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - M R Passmore
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - K Hyslop
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - E S Wood
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - J Reid
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - S M Colombo
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.,University of Milan, Milan, Italy
| | | | - M A Wells
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.,School of Medical Science, Griffith University, Brisbane, Australia
| | - D Black
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - L P Pimenta
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - A K Stevenson
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - K Bisht
- Mater Research Institute-The University of Queensland, Woolloongabba, QLD, Australia
| | - L Marshall
- The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - D A Prabhu
- The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - L James
- Princess Alexandra Hospital, Woolloongabba, Brisbane, QLD, 4102, Australia
| | - D G Platts
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia
| | - P S Macdonald
- Cardiac Mechanics Research Laboratory, St. Vincent's Hospital and the Victor Chang Cardiac Research Institute, Victoria Street, Darlinghurst, Sydney, NSW, 2061, Australia
| | - D C McGiffin
- Cardiothoracic Surgery and Transplantation, The Alfred Hospital, Melbourne, Australia
| | - J Y Suen
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.
| | - J F Fraser
- Critical Care Research Group, Level 3, Clinical Sciences Building, The Prince Charles Hospital, Rode Road, Brisbane, Australia.
| |
Collapse
|
4
|
Hoe LS, Wells M, Bouquet M, Hyslop K, Passmore M, Bartnikowski N, Obonyo N, Reid J, O'Neill H, Shuker T, McDonald C, Engkilde-Pedersen S, Wildi K, Ainola C, Skeggs K, Jung J, Colombo S, Sato K, James L, He P, Wood E, Heinser S, Wang X, Abbate G, Livingstone S, Haymet A, Walweel K, Mullins D, Marasco S, Diab S, Tung J, Molenaar P, Bassi GL, Suen J, McGiffin D, Fraser J. Metabolic and Mitochondrial Alterations Following Brain Death and Heart Transplantation. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
5
|
Walweel K, Gomez-Hurtado N, Oo YW, Beard NA, Dos Remedios C, Johnson CN, Chazin WJ, van Helden DF, Knollmann BC, Laver DR. Calmodulin Mutants Linked to Catecholaminergic Polymorphic Ventricular Tachycardia Fail to Inhibit Human RyR2 Channels. J Am Coll Cardiol 2019; 70:115-117. [PMID: 28662798 DOI: 10.1016/j.jacc.2017.04.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/11/2017] [Accepted: 04/26/2017] [Indexed: 10/19/2022]
|
6
|
Walweel K, Gomez-Hurtado N, Rebbeck RT, Oo YW, Beard NA, Molenaar P, Dos Remedios C, van Helden DF, Cornea RL, Knollmann BC, Laver DR. Calmodulin inhibition of human RyR2 channels requires phosphorylation of RyR2-S2808 or RyR2-S2814. J Mol Cell Cardiol 2019; 130:96-106. [PMID: 30928430 DOI: 10.1016/j.yjmcc.2019.03.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/19/2019] [Accepted: 03/25/2019] [Indexed: 01/08/2023]
Abstract
Calmodulin (CaM) is a Ca-binding protein that binds to, and can directly inhibit cardiac ryanodine receptor calcium release channels (RyR2). Animal studies have shown that RyR2 hyperphosphorylation reduces CaM binding to RyR2 in failing hearts, but data are lacking on how CaM regulates human RyR2 and how this regulation is affected by RyR2 phosphorylation. Physiological concentrations of CaM (100 nM) inhibited the diastolic activity of RyR2 isolated from failing human hearts by ~50% but had no effect on RyR2 from healthy human hearts. Using FRET between donor-FKBP12.6 and acceptor-CaM bound to RyR2, we determined that CaM binds to RyR2 from healthy human heart with a Kd = 121 ± 14 nM. Ex-vivo phosphorylation/dephosphorylation experiments suggested that the divergent CaM regulation of healthy and failing human RyR2 was caused by differences in RyR2 phosphorylation by protein kinase A and Ca-CaM-dependent kinase II. Ca2+-spark measurements in murine cardiomyocytes harbouring RyR2 phosphomimetic or phosphoablated mutants at S2814 and S2808 suggest that phosphorylation of residues corresponding to either human RyR2-S2808 or S2814 is both necessary and sufficient for RyR2 regulation by CaM. Our results challenge the current concept that CaM universally functions as a canonical inhibitor of RyR2 across species. Rather, CaM's biological action on human RyR2 appears to be more nuanced, with inhibitory activity only on phosphorylated RyR2 channels, which occurs during exercise or in patients with heart failure.
Collapse
Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia.
| | - Nieves Gomez-Hurtado
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Ye Wint Oo
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia
| | - Nicole A Beard
- Faculty of Science and Technology, University of Canberra, Bruce, ACT 2617, Australia.
| | - Peter Molenaar
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia; Northside Clinical School of Medicine, University of Queensland, Cardio-vascular Molecular & Therapeutics Translational Research Group, The Prince Charles Hospital, Chermside, QLD 4032. Australia.
| | - Cris Dos Remedios
- Bosch Institute, Discipline of Anatomy, University of Sydney, Sydney, New South Wales 2006, Australia.
| | - Dirk F van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia.
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Björn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia.
| |
Collapse
|
7
|
Walweel K, Oo YW, Laver DR. The emerging role of calmodulin regulation of RyR2 in controlling heart rhythm, the progression of heart failure and the antiarrhythmic action of dantrolene. Clin Exp Pharmacol Physiol 2017; 44:135-142. [PMID: 27626620 DOI: 10.1111/1440-1681.12669] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/27/2016] [Accepted: 09/09/2016] [Indexed: 11/28/2022]
Abstract
Cardiac output and rhythm depend on the release and the take-up of calcium from the sarcoplasmic reticulum (SR). Excessive diastolic calcium leak from the SR due to dysfunctional calcium release channels (RyR2) contributes to the formation of delayed after-depolarizations, which underlie the fatal arrhythmias that occur in heart failure and inherited syndromes. Calmodulin (CaM) is a calcium-binding protein that regulates target proteins and acts as a calcium sensor. CaM is comprised of two calcium-binding EF-hand domains and a flexible linker. CaM is an accessory protein that partially inhibits RyR2 channel activity. CaM is critical for normal cardiac function, and altered CaM binding and efficacy may contribute to defects in SR calcium release. The present paper reviews CaM binding to RyR2 and how it regulates RyR2 channel activity. It then goes on to review how mutations in the CaM amino acid sequence give rise to inherited syndromes such as Catecholaminergic Polymorphic Ventricular Tachychardia (CPVT) and long QT syndrome (LQTS). In addition, the role of reduced CaM binding to RyR2 that results from RyR2 phosphorylation or from oxidation of either RyR2 or CaM contributes to the progression of heart failure is reviewed. Finally, this manuscript reviews recent evidence that CaM binding to RyR2 is required for the inhibitory action of a pharmaceutical agent (dantrolene) on RyR2. Dantrolene is a clinically used muscle relaxant that has recently been found to exert antiarrhythmic effects against SR Ca2+ overload arrhythmias.
Collapse
Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW, 2308, Australia
| | - Ye Win Oo
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW, 2308, Australia
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW, 2308, Australia
| |
Collapse
|
8
|
Gomez-Hurtado N, Walweel K, Laver D, Knollmann BC. Calmodulin Regulation of Ryanodine Receptors (RyR2) Depends on RyR2 Phosphorylation at Residues S2808 and S2814. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.1275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
9
|
Walweel K, Molenaar P, Imtiaz MS, Denniss A, Dos Remedios C, van Helden DF, Dulhunty AF, Laver DR, Beard NA. Ryanodine receptor modification and regulation by intracellular Ca 2+ and Mg 2+ in healthy and failing human hearts. J Mol Cell Cardiol 2017; 104:53-62. [PMID: 28131631 DOI: 10.1016/j.yjmcc.2017.01.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 01/01/2017] [Accepted: 01/24/2017] [Indexed: 11/30/2022]
Abstract
RATIONALE Heart failure is a multimodal disorder, of which disrupted Ca2+ homeostasis is a hallmark. Central to Ca2+ homeostasis is the major cardiac Ca2+ release channel - the ryanodine receptor (RyR2) - whose activity is influenced by associated proteins, covalent modification and by Ca2+ and Mg2+. That RyR2 is remodelled and its function disturbed in heart failure is well recognized, but poorly understood. OBJECTIVE To assess Ca2+ and Mg2+ regulation of RyR2 from left ventricles of healthy, cystic fibrosis and failing hearts, and to correlate these functional changes with RyR2 modifications and remodelling. METHODS AND RESULTS The function of RyR2 from left ventricular samples was assessed using lipid bilayer single-channel measurements, whilst RyR2 modification and protein:protein interactions were determined using Western Blots and co-immunoprecipitation. In all failing hearts there was an increase in RyR2 activity at end-diastolic cytoplasmic Ca2+ (100nM), a decreased cytoplasmic [Ca2+] required for half maximal activation (Ka) and a decrease in inhibition by cytoplasmic Mg2+. This was accompanied by significant hyperphosphorylation of RyR2 S2808 and S2814, reduced free thiol content and a reduced interaction with FKBP12.0 and FKBP12.6. Either dephosphorylation of RyR2 using PP1 or thiol reduction using DTT eliminated any significant difference in the activity of RyR2 from healthy and failing hearts. We also report a subgroup of RyR2 in failing hearts that were not responsive to regulation by intracellular Ca2+ or Mg2+. CONCLUSION Despite different aetiologies, disrupted RyR2 Ca2+ sensitivity and biochemical modification of the channel are common constituents of failing heart RyR2 and may underlie the pathological disturbances in intracellular Ca2+ signalling.
Collapse
Affiliation(s)
- K Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia
| | - P Molenaar
- Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, 4000, Northside Clinical School, School of Clinical Medicine, University of Queensland and Critical Care Research Group, The Prince Charles Hospital, Chermside, QLD, 4032, Australia
| | - M S Imtiaz
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia
| | - A Denniss
- Health Research Institute, Faculty of Education Science and Mathematics, University of Canberra, Bruce, ACT 2617, Australia
| | - C Dos Remedios
- Bosch Institute, Discipline of Anatomy, University of Sydney, Sydney, New South Wales 2006, Australia
| | - D F van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia
| | - A F Dulhunty
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, 0200, Australia
| | - D R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308, Australia
| | - N A Beard
- Health Research Institute, Faculty of Education Science and Mathematics, University of Canberra, Bruce, ACT 2617, Australia; John Curtin School of Medical Research, Australian National University, Canberra, ACT, 0200, Australia.
| |
Collapse
|
10
|
Walweel K, Li J, Molenaar P, Imtiaz MS, Quail A, dos Remedios CG, Beard NA, Dulhunty AF, van Helden DF, Laver DR. Differences in the regulation of RyR2 from human, sheep, and rat by Ca²⁺ and Mg²⁺ in the cytoplasm and in the lumen of the sarcoplasmic reticulum. ACTA ACUST UNITED AC 2015; 144:263-71. [PMID: 25156119 PMCID: PMC4144672 DOI: 10.1085/jgp.201311157] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cardiac ryanodine receptors (RyR2) from humans, rats, and sheep show differential sensitivity to calcium and magnesium, with regulation of human RyR2 resembling that of sheep more than that of rat. Regulation of the cardiac ryanodine receptor (RyR2) by intracellular Ca2+ and Mg2+ plays a key role in determining cardiac contraction and rhythmicity, but their role in regulating the human RyR2 remains poorly defined. The Ca2+- and Mg2+-dependent regulation of human RyR2 was recorded in artificial lipid bilayers in the presence of 2 mM ATP and compared with that in two commonly used animal models for RyR2 function (rat and sheep). Human RyR2 displayed cytoplasmic Ca2+ activation (Ka = 4 µM) and inhibition by cytoplasmic Mg2+ (Ki = 10 µM at 100 nM Ca2+) that was similar to RyR2 from rat and sheep obtained under the same experimental conditions. However, in the presence of 0.1 mM Ca2+, RyR2s from human were 3.5-fold less sensitive to cytoplasmic Mg2+ inhibition than those from sheep and rat. The Ka values for luminal Ca2+ activation were similar in the three species (35 µM for human, 12 µM for sheep, and 10 µM for rat). From the relationship between open probability and luminal [Ca2+], the peak open probability for the human RyR2 was approximately the same as that for sheep, and both were ∼10-fold greater than that for rat RyR2. Human RyR2 also showed the same sensitivity to luminal Mg2+ as that from sheep, whereas rat RyR2 was 10-fold more sensitive. In all species, modulation of RyR2 gating by luminal Ca2+ and Mg2+ only occurred when cytoplasmic [Ca2+] was <3 µM. The activation response of RyR2 to luminal and cytoplasmic Ca2+ was strongly dependent on the Mg2+ concentration. Addition of physiological levels (1 mM) of Mg2+ raised the Ka for cytoplasmic Ca2+ to 30 µM (human and sheep) or 90 µM (rat) and raised the Ka for luminal Ca2+ to ∼1 mM in all species. This is the first report of the regulation by Ca2+ and Mg2+ of native RyR2 receptor activity from healthy human hearts.
Collapse
Affiliation(s)
- Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales 2308, Australia
| | - Jiao Li
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales 2308, Australia
| | - Peter Molenaar
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland 4001, Australia School of Medicine, University of Queensland, Brisbane, Queensland 4006, Australia Critical Care Research Group, The Prince Charles Hospital Foundation, Chermside, Queensland 4032, Australia
| | - Mohammad S Imtiaz
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales 2308, Australia
| | - Anthony Quail
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales 2308, Australia
| | - Cris G dos Remedios
- Bosch Institute, Discipline of Anatomy, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Nicole A Beard
- Faculty of Education, Science, Technology, and Mathematics, University of Canberra, Canberra, Australian Capital Territory 2601, Australia
| | - Angela F Dulhunty
- The John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2600, Australia
| | - Dirk F van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales 2308, Australia
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales 2308, Australia
| |
Collapse
|
11
|
Oo YW, Gomez-Hurtado N, Walweel K, van Helden DF, Imtiaz MS, Knollmann BC, Laver DR. Essential Role of Calmodulin in RyR Inhibition by Dantrolene. Mol Pharmacol 2015; 88:57-63. [PMID: 25920678 DOI: 10.1124/mol.115.097691] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 04/28/2015] [Indexed: 12/17/2022] Open
Abstract
Dantrolene is the first line therapy of malignant hyperthermia. Animal studies suggest that dantrolene also protects against heart failure and arrhythmias caused by spontaneous Ca(2+) release. Although dantrolene inhibits Ca(2+) release from the sarcoplasmic reticulum of skeletal and cardiac muscle preparations, its mechanism of action has remained controversial, because dantrolene does not inhibit single ryanodine receptor (RyR) Ca(2+) release channels in lipid bilayers. Here we test the hypothesis that calmodulin (CaM), a physiologic RyR binding partner that is lost during incorporation into lipid bilayers, is required for dantrolene inhibition of RyR channels. In single channel recordings (100 nM cytoplasmic [Ca(2+)] + 2 mM ATP), dantrolene caused inhibition of RyR1 (rabbit skeletal muscle) and RyR2 (sheep) with a maximal inhibition of Po (Emax) to 52 ± 4% of control only after adding physiologic [CaM] = 100 nM. Dantrolene inhibited RyR2 with an IC50 of 0.16 ± 0.03 µM. Mutant N98S-CaM facilitated dantrolene inhibition with an IC50 = 5.9 ± 0.3 nM. In mouse cardiomyocytes, dantrolene had no effect on cardiac Ca(2+) release in the absence of CaM, but reduced Ca(2+) wave frequency (IC50 = 0.42 ± 0.18 µM, Emax = 47 ± 4%) and amplitude (IC50 = 0.19 ± 0.04 µM, Emax = 66 ± 4%) in the presence of 100 nM CaM. We conclude that CaM is essential for dantrolene inhibition of RyR1 and RyR2. Its absence explains why dantrolene inhibition of single RyR channels has not been previously observed.
Collapse
Affiliation(s)
- Ye Win Oo
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| | - Nieves Gomez-Hurtado
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| | - Kafa Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| | - Dirk F van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| | - Mohammad S Imtiaz
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| | - Bjorn C Knollmann
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (Y.W.O., K.W., D.F.H., M.S.I., D.R.L.); and Division of Clinical Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee (N.G.-H., B.C.K.)
| |
Collapse
|
12
|
Abstract
Normal heart contraction and rhythm relies on the proper flow of calcium ions (Ca2+) into cardiac cells and between their intracellular organelles, and any disruption can lead to arrhythmia and sudden cardiac death. Electrical excitation of the surface membrane activates voltage-dependent L-type Ca2+ channels to open and allow Ca2+ to enter the cytoplasm. The subsequent increase in cytoplasmic Ca2+ concentration activates calcium release channels (RyR2) located at specialised Ca2+ release sites in the sarcoplasmic reticulum (SR), which serves as an intracellular Ca2+ store. Animal models have provided valuable insights into how intracellular Ca2+ transport mechanisms are altered in human heart failure. The aim of this review is to examine how Ca2+ release sites are remodelled in heart failure and how this affects intracellular Ca2+ transport with an emphasis on Ca2+ release mechanisms in the SR. Current knowledge on how heart failure alters the regulation of RyR2 by Ca2+ and Mg2+ and how these mechanisms control the activity of RyR2 in the confines of the Ca2+ release sites is reviewed.
Collapse
Affiliation(s)
- K Walweel
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW, 2308, Australia
| | - D R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW, 2308, Australia.
| |
Collapse
|
13
|
Hwang HS, Nitu FR, Yang Y, Walweel K, Pereira L, Johnson CN, Faggioni M, Chazin WJ, Laver D, George AL, Cornea RL, Bers DM, Knollmann BC. Divergent regulation of ryanodine receptor 2 calcium release channels by arrhythmogenic human calmodulin missense mutants. Circ Res 2014; 114:1114-24. [PMID: 24563457 DOI: 10.1161/circresaha.114.303391] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
RATIONALE Calmodulin (CaM) mutations are associated with an autosomal dominant syndrome of ventricular arrhythmia and sudden death that can present with divergent clinical features of catecholaminergic polymorphic ventricular tachycardia (CPVT) or long QT syndrome (LQTS). CaM binds to and inhibits ryanodine receptor (RyR2) Ca release channels in the heart, but whether arrhythmogenic CaM mutants alter RyR2 function is not known. OBJECTIVE To gain mechanistic insight into how human CaM mutations affect RyR2 Ca channels. METHODS AND RESULTS We studied recombinant CaM mutants associated with CPVT (N54I and N98S) or LQTS (D96V, D130G, and F142L). As a group, all LQTS-associated CaM mutants (LQTS-CaMs) exhibited reduced Ca affinity, whereas CPVT-associated CaM mutants (CPVT-CaMs) had either normal or modestly lower Ca affinity. In permeabilized ventricular myocytes, CPVT-CaMs at a physiological intracellular concentration (100 nmol/L) promoted significantly higher spontaneous Ca wave and spark activity, a typical cellular phenotype of CPVT. Compared with wild-type CaM, CPVT-CaMs caused greater RyR2 single-channel open probability and showed enhanced binding affinity to RyR2. Even a 1:8 mixture of CPVT-CaM:wild-type-CaM activated Ca waves, demonstrating functional dominance. In contrast, LQTS-CaMs did not promote Ca waves and exhibited either normal regulation of RyR2 single channels (D96V) or lower RyR2-binding affinity (D130G and F142L). None of the CaM mutants altered Ca/CaM binding to CaM-kinase II. CONCLUSIONS A small proportion of CPVT-CaM is sufficient to evoke arrhythmogenic Ca disturbances, whereas LQTS-CaMs do not. Our findings explain the clinical presentation and autosomal dominant inheritance of CPVT-CaM mutations and suggest that RyR2 interactions are unlikely to explain arrhythmogenicity of LQTS-CaM mutations.
Collapse
Affiliation(s)
- Hyun Seok Hwang
- From the Departments of Medicine (H.S.H., M.F., A.L.G., B.C.K.), Biochemistry (C.N.J., W.J.C.), Chemistry (W.J.C.), and Pharmacology (A.L.G., B.C.K.), Vanderbilt University, Nashville, TN; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis (F.R.N., R.L.C.); Department of Pharmacology, University of California, Davis (Y.Y., L.P., D.M.B.); and Department of School of Biomedical Sciences and Pharmacy, University of Newcastle, New South Wales, Australia (K.W., D.L.)
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|