Ryanodine receptor modification and regulation by intracellular Ca2 + and Mg2 + in healthy and failing human hearts

Kafa Walweel, Peter Molenaar, Mohammad Imtiaz, Amanda Denniss, Cris dos Remedios, Dirk van Helden, Angela F. Dulhunty, Derek laver, Nicole BEARD

Research output: Contribution to journalArticle

7 Citations (Scopus)

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 + (100 nM), 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.
Original languageEnglish
Pages (from-to)53-62
Number of pages10
JournalJournal of Molecular and Cellular Cardiology
Volume104
DOIs
Publication statusPublished - Mar 2017

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Ryanodine Receptor Calcium Release Channel
Sulfhydryl Compounds
Homeostasis
Heart Failure
Proteins
Lipid Bilayers
Left Ventricular Function
Immunoprecipitation
Cystic Fibrosis
Heart Ventricles

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Walweel, Kafa ; Molenaar, Peter ; Imtiaz, Mohammad ; Denniss, Amanda ; dos Remedios, Cris ; van Helden, Dirk ; Dulhunty, Angela F. ; laver, Derek ; BEARD, Nicole. / Ryanodine receptor modification and regulation by intracellular Ca2 + and Mg2 + in healthy and failing human hearts. In: Journal of Molecular and Cellular Cardiology. 2017 ; Vol. 104. pp. 53-62.
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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 + (100 nM), 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.",
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Ryanodine receptor modification and regulation by intracellular Ca2 + and Mg2 + in healthy and failing human hearts. / Walweel, Kafa; Molenaar, Peter; Imtiaz, Mohammad; Denniss, Amanda; dos Remedios, Cris; van Helden, Dirk; Dulhunty, Angela F.; laver, Derek; BEARD, Nicole.

In: Journal of Molecular and Cellular Cardiology, Vol. 104, 03.2017, p. 53-62.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ryanodine receptor modification and regulation by intracellular Ca2 + and Mg2 + in healthy and failing human hearts

AU - Walweel, Kafa

AU - Molenaar, Peter

AU - Imtiaz, Mohammad

AU - Denniss, Amanda

AU - dos Remedios, Cris

AU - van Helden, Dirk

AU - Dulhunty, Angela F.

AU - laver, Derek

AU - BEARD, Nicole

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N2 - 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 + (100 nM), 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.

AB - 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 + (100 nM), 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.

KW - Heart failure

KW - Lipid bilayer

KW - Mg and Ca signalling

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