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Journal of Molecular and Cellular... May 2023Dantrolene binds to the Leu-Cys region of the N-terminal domain of cardiac ryanodine receptor (RyR2), which corresponds to the Leu-Cys region of the skeletal ryanodine...
BACKGROUND
Dantrolene binds to the Leu-Cys region of the N-terminal domain of cardiac ryanodine receptor (RyR2), which corresponds to the Leu-Cys region of the skeletal ryanodine receptor, and suppresses diastolic Ca leakage through RyR2.
OBJECTIVE
We investigated whether the chronic administration of dantrolene prevented left ventricular (LV) remodeling and ventricular tachycardia (VT) after myocardial infarction (MI) by the same mechanism with the mutation V3599K of RyR2, which indicated that the inhibition of diastolic Ca leakage occurred by enhancing the binding affinity of calmodulin (CaM) to RyR2.
METHODS AND RESULTS
A left anterior descending coronary artery ligation MI model was developed in mice. Wild-type (WT) were divided into four groups: sham-operated mice (WT-Sham), sham-operated mice treated with dantrolene (WT-Sham-DAN), MI mice (WT-MI), and MI mice treated with dantrolene (WT-MI-DAN). Homozygous V3599K RyR2 knock-in (KI) mice were divided into two groups: sham-operated mice (KI-Sham) and MI mice (KI-MI). The mice were followed for 12 weeks. Survival was significantly higher in the WT-MI-DAN (73%) and KI-MI groups (70%) than the WT-MI group (40%). Echocardiography, pathological tissue, and epinephrine-induced VT studies showed that LV remodeling and VT were prevented in the WT-MI-DAN and KI-MI groups compared to the WT-MI group. An increase in diastolic Ca spark frequency and a decrease in the binding affinity of CaM to the RyR2 were observed at 12 weeks after MI in the WT-MI group, although significant improvements in these values were observed in the WT-MI-DAN and KI-MI groups.
CONCLUSIONS
Pharmacological or genetic stabilization of RyR2 tetrameric structure improves survival after MI by suppressing LV remodeling and proarrhythmia.
Topics: Mice; Animals; Ryanodine Receptor Calcium Release Channel; Dantrolene; Ventricular Remodeling; Myocytes, Cardiac; Tachycardia, Ventricular; Arrhythmias, Cardiac; Heart Failure; Calmodulin; Myocardial Infarction
PubMed: 36963751
DOI: 10.1016/j.yjmcc.2023.03.007 -
Biochemical Pharmacology Jun 2022Inherited arrhythmias are the leading causes for cardiac arrest and sudden cardiac death (SCD). Other than ion channel mutations, inherited arrhythmias including... (Review)
Review
Inherited arrhythmias are the leading causes for cardiac arrest and sudden cardiac death (SCD). Other than ion channel mutations, inherited arrhythmias including catecholaminergic polymorphic ventricular tachycardia (CPVT), long QT syndrome (LQTS), idiopathic ventricular fibrillation (IVF) and arrhythmogenic right ventricular cardiomyopathy (ARVC/D) may also be instigated by genetic mutations of sarcoplasmic reticulum (SR) proteins, including ryanodine receptor type-2 (RyR2), calsequestrin 2, SR Ca-ATPase type-2a (SERCA2a) and phospholamban. In cardiomyocytes, Ca is an essential ion in addition to Na and K ions with vital roles in arrhythmogenesis. SR plays a critical role in the maintenance of Ca homeostasis which can be disrupted by mutations in SR Ca regulatory proteins or abnormal SR-intracellular organelle interaction. Early afterdepolarizations, delayed afterdepolarizations and reentry are three primary mechanisms contributing to arrhythmias elicited by SR Ca dysregulation in cardiomyocytes. In this review, we will aim to summarize normal SR Ca regulation in cardiomyocytes, mechanisms of how Ca triggers arrhythmias and involvements of SR gene mutations in inherited arrhythmias as well as the possible arrhythmogenic effects of these mutations.
Topics: Arrhythmias, Cardiac; Calcium; Humans; Mutation; Myocytes, Cardiac; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum; Tachycardia, Ventricular
PubMed: 35490731
DOI: 10.1016/j.bcp.2022.115059 -
BioRxiv : the Preprint Server For... Jul 2023Ca leak from cardiac ryanodine receptor (RyR2) is an established mechanism of sudden cardiac death (SCD), whereby dysregulated Ca handling causes ventricular...
UNLABELLED
Ca leak from cardiac ryanodine receptor (RyR2) is an established mechanism of sudden cardiac death (SCD), whereby dysregulated Ca handling causes ventricular arrhythmias. We previously discovered the RyR2-selective inhibitor (+)-verticilide ( -1), a 24-membered cyclooligomeric depsipeptide that is the enantiomeric form of a natural product ( -(-)-verticilide). Here, we examined its 18-membered ring-size oligomer ( -verticilide B1; " -B1") in single RyR2 channel assays, [ H]ryanodine binding assays, and in cardiomyocytes and mice, a gene-targeted model of SCD. -B1 inhibited RyR2 single-channels and [ H]ryanodine binding with low micromolar potency, and RyR2-mediated spontaneous Ca release in Casq2-/- cardiomyocytes with sub-micromolar potency. -B1 was a partial RyR2 inhibitor, with maximal inhibitory efficacy of less than 50%. -B1 was stable in plasma, with a peak plasma concentration of 1460 ng/ml at 10 min and half-life of 45 min after intraperitoneal administration of 3 mg/kg in mice. Both 3 mg/kg and 30 mg/kg -B1 significantly reduced catecholamine-induced ventricular arrhythmia in Casq2-/- mice. Hence, we have identified a novel chemical entity - -B1 - that preserves the mechanism of action of a hit compound and shows therapeutic efficacy. These findings strengthen RyR2 as an antiarrhythmic drug target and highlight the potential of investigating the mirror-image isomers of natural products to discover new therapeutics.
SIGNIFICANCE STATEMENT
The cardiac ryanodine receptor (RyR2) is an untapped target in the stagnant field of antiarrhythmic drug development. We have confirmed RyR2 as an antiarrhythmic target in a mouse model of sudden cardiac death and shown the therapeutic efficacy of a second enantiomeric natural product.
PubMed: 37461611
DOI: 10.1101/2023.07.03.547578 -
Expert Opinion on Therapeutic Targets 2023Recent neuroscience breakthroughs have shed light on the sophisticated relationship between calcium channelopathies and movement disorders, exposing a previously... (Review)
Review
INTRODUCTION
Recent neuroscience breakthroughs have shed light on the sophisticated relationship between calcium channelopathies and movement disorders, exposing a previously undiscovered tale focusing on the Ryanodine Receptor (RyR) and the Sarco/Endoplasmic Reticulum Calcium ATPase (SERCA). Calcium signaling mainly orchestrates neural communication, which regulates synaptic transmission and total network activity. It has been determined that RyR play a significant role in managing neuronal functions, most notably in releasing intracellular calcium from the endoplasmic reticulum.
AREAS COVERED
It highlights the involvement of calcium channels such as RyR and SERCA in physiological and pathophysiological conditions.
EXPERT OPINION
Links between RyR and SERCA activity dysregulation, aberrant calcium levels, motor and cognitive dysfunction have brought attention to the importance of RyR and SERCA modulation in neurodegenerative disorders. Understanding the obscure function of these proteins will open up new therapeutic possibilities to address the underlying causes of neurodegenerative diseases. The unreported RyR and SERCA narrative broadens the understanding of calcium channelopathies in movement disorders and calls for more research into cutting-edge therapeutic approaches.
Topics: Humans; Ryanodine Receptor Calcium Release Channel; Calcium; Calcium Signaling; Channelopathies; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Endoplasmic Reticulum; Neurodegenerative Diseases; Movement Disorders
PubMed: 37971192
DOI: 10.1080/14728222.2023.2277863 -
The Journal of Physiology Oct 2023Store-operated Ca entry (SOCE) is critical to cell function. In skeletal muscle, SOCE has evolved alongside excitation-contraction coupling (EC coupling); as a result,... (Review)
Review
Store-operated Ca entry (SOCE) is critical to cell function. In skeletal muscle, SOCE has evolved alongside excitation-contraction coupling (EC coupling); as a result, it displays unique properties compared to SOCE in other cells. The plasma membrane of skeletal muscle is mostly internalized as the tubular system, with the tubules meeting the sarcoplasmic reticulum (SR) terminal cisternae, forming junctions where the proteins that regulate EC coupling and SOCE are positioned. In this review, we describe the properties and roles of SOCE based on direct measurements of Ca influx during SR Ca release and leak. SOCE is activated immediately and locally as the [Ca ] of the junctional SR terminal cisternae ([Ca ] ) depletes. [Ca ] changes rapidly and steeply with increasing activity of the SR ryanodine receptor isoform 1 (RyR1). The high fidelity of [Ca ] with RyR1 activity probably depends on the SR Ca -buffer calsequestrin that is located immediately behind RyR1 inside the SR. This arrangement provides in-phase activation and deactivation of SOCE with a large dynamic range, allowing precise grading of SOCE flux. The in-phase activation of SOCE as the SR partially depletes traps Ca in the cytoplasm, preventing net Ca loss. Mild presentation of RyR1 leak can occur under physiological conditions, providing fibre Ca redistribution without changing fibre Ca content. This condition preserves normal contractile function at the same time as increasing basal metabolic rate. However, higher RyR1 leak drives excess cytoplasmic and mitochondrial Ca load, setting a deleterious intracellular environment that compromises the function of the skeletal muscle.
Topics: Ryanodine Receptor Calcium Release Channel; Muscle, Skeletal; Calcium Signaling; Sarcoplasmic Reticulum; Cytoplasm; Calcium
PubMed: 35218018
DOI: 10.1113/JP279512 -
Current Opinion in Pharmacology Apr 2023Type 1 ryanodine receptor (RyR1) is an intracellular Ca release channel on the sarcoplasmic reticulum of skeletal muscle, and it plays a central role in... (Review)
Review
Type 1 ryanodine receptor (RyR1) is an intracellular Ca release channel on the sarcoplasmic reticulum of skeletal muscle, and it plays a central role in excitation-contraction (E-C) coupling. Mutations in RyR1 are implicated in various muscle diseases including malignant hyperthermia, central core disease, and myopathies. Currently, no specific treatment exists for most of these diseases. Recently, high-throughput screening (HTS) assays have been developed for identifying potential candidates for treating RyR-related muscle diseases. Currently, two different methods, namely a FRET-based assay and an endoplasmic reticulum Ca-based assay, are available. These assays identified several compounds as novel RyR1 inhibitors. In addition, the development of a reconstituted platform permitted HTS assays for E-C coupling modulators. In this review, we will focus on recent progress in HTS assays and discuss future perspectives of these promising approaches.
Topics: Humans; Ryanodine Receptor Calcium Release Channel; Muscular Diseases; Calcium Signaling; Muscle, Skeletal; Drug Development; Calcium; Mutation
PubMed: 36842386
DOI: 10.1016/j.coph.2023.102356 -
Frontiers in Immunology 2023Mast cell (MC) activation is implicated in the pathogenesis of multiple immunodysregulatory skin disorders. Activation of an IgE-independent pseudo-allergic route has...
Mast cell (MC) activation is implicated in the pathogenesis of multiple immunodysregulatory skin disorders. Activation of an IgE-independent pseudo-allergic route has been recently found to be mainly mediated Mas-Related G protein-coupled receptor X2 (MRGPRX2). Ryanodine receptor (RYR) regulates intracellular calcium liberation. Calcium mobilization is critical in the regulation of MC functional programs. However, the role of RYR in MRGPRX2-mediated pseudo-allergic skin reaction has not been fully addressed. To study the role of RYR , we established a murine skin pseudo-allergic reaction model. RYR inhibitor attenuated MRGPRX2 ligand substance P (SP)-induced vascular permeability and neutrophil recruitment. Then, we confirmed the role of RYR in an MC line (LAD2 cells) and primary human skin-derived MCs. In LAD2 cells, RYR inhibitor pretreatment dampened MC degranulation (detected by β-hexosaminidase retlease), calcium mobilization, IL-13, TNF-α, CCL-1, CCL-2 mRNA, and protein expression activated by MRGPRX2 ligands, namely, compound 48/80 (c48/80) and SP. Moreover, the inhibition effect of c48/80 by RYR inhibitor was verified in skin MCs. After the confirmation of RYR2 and RYR3 expression, the isoforms were silenced by siRNA-mediated knockdown. MRGPRX2-induced LAD2 cell exocytosis and cytokine generation were substantially inhibited by RYR3 knockdown, while RYR2 had less contribution. Collectively, our finding suggests that RYR activation contributes to MRGPRX2-triggered pseudo-allergic dermatitis, and provides a potential approach for MRGPRX2-mediated disorders.
Topics: Humans; Animals; Mice; Calcium; Ryanodine; Ryanodine Receptor Calcium Release Channel; Mast Cells; Receptors, G-Protein-Coupled; Dermatitis, Atopic; Nerve Tissue Proteins; Receptors, Neuropeptide
PubMed: 37404822
DOI: 10.3389/fimmu.2023.1207249 -
Disease Models & Mechanisms Dec 2019The core myopathies are a group of congenital myopathies with variable clinical expression - ranging from early-onset skeletal-muscle weakness to later-onset disease of... (Review)
Review
The core myopathies are a group of congenital myopathies with variable clinical expression - ranging from early-onset skeletal-muscle weakness to later-onset disease of variable severity - that are identified by characteristic 'core-like' lesions in myofibers and the presence of hypothonia and slowly or rather non-progressive muscle weakness. The genetic causes are diverse; central core disease is most often caused by mutations in ryanodine receptor 1 (), whereas multi-minicore disease is linked to pathogenic variants of several genes, including selenoprotein N (), and titin (). Understanding the mechanisms that drive core development and muscle weakness remains challenging due to the diversity of the excitation-contraction coupling (ECC) proteins involved and the differential effects of mutations across proteins. Because of this, the use of representative models expressing a mature ECC apparatus is crucial. Animal models have facilitated the identification of disease progression mechanisms for some mutations and have provided evidence to help explain genotype-phenotype correlations. However, many unanswered questions remain about the common and divergent pathological mechanisms that drive disease progression, and these mechanisms need to be understood in order to identify therapeutic targets. Several new transgenic animals have been described recently, expanding the spectrum of core myopathy models, including mice with patient-specific mutations. Furthermore, recent developments in 3D tissue engineering are expected to enable the study of core myopathy disease progression and the effects of potential therapeutic interventions in the context of human cells. In this Review, we summarize the current landscape of core myopathy models, and assess the hurdles and opportunities of future modeling strategies.
Topics: Alkaloids; Animals; Connectin; Disease Models, Animal; Disease Progression; Gene Expression Regulation; Genetic Association Studies; Genetic Variation; HEK293 Cells; Humans; Male; Mice; Mice, Transgenic; Muscle Proteins; Muscle Weakness; Muscle, Skeletal; Myopathies, Structural, Congenital; Myopathy, Central Core; Ophthalmoplegia; Protein Kinases; Ryanodine; Ryanodine Receptor Calcium Release Channel; Selenoproteins
PubMed: 31874912
DOI: 10.1242/dmm.041368 -
Nature Reviews. Disease Primers Jul 2020
Topics: Arrhythmias, Cardiac; Brugada Syndrome; Disease Management; Electrocardiography; Humans; Long QT Syndrome; Ryanodine Receptor Calcium Release Channel; Tachycardia, Ventricular
PubMed: 32678096
DOI: 10.1038/s41572-020-0202-0 -
Circulation Sep 2020
Topics: Atrial Fibrillation; Humans; Muscle Proteins; Protein Serine-Threonine Kinases; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum
PubMed: 32955933
DOI: 10.1161/CIRCULATIONAHA.120.050226