keyword
MENU ▼
Read by QxMD icon Read
search

"ryanodine receptor" OR "ryr" OR "ryr2"

keyword
https://www.readbyqxmd.com/read/28428008/force-development-and-intracellular-ca-2-in-intact-cardiac-muscles-from-gravin-mutant-mice
#1
Zhitao Li, Sonal Singh, Santosh V Suryavanshi, Wengang Ding, Xiaoxu Shen, Cori S Wijaya, Wei Dong Gao, Bradley K McConnell
Gravin (AKAP12) is an A-kinase-anchoring-protein that scaffolds protein kinase A (PKA), β2-adrenergic receptor (β2-AR), protein phosphatase 2B and protein kinase C. Gravin facilitates β2-AR-dependent signal transduction through PKA to modulate cardiac excitation-contraction coupling and its removal positively affects cardiac contraction. Trabeculae from the right ventricles of gravin mutant (gravin-t/t) mice were employed for force determination. Simultaneously, corresponding intracellular Ca(2+) transient ([Ca(2+)]i) were measured...
April 17, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28422759/ryr2r420q-catecholaminergic-polymorphic-ventricular-tachycardia-mutation-induces-bradycardia-by-disturbing-the-coupled-clock-pacemaker-mechanism
#2
Yue Yi Wang, Pietro Mesirca, Elena Marqués-Sulé, Alexandra Zahradnikova, Olivier Villejoubert, Pilar D'Ocon, Cristina Ruiz, Diana Domingo, Esther Zorio, Matteo E Mangoni, Jean-Pierre Benitah, Ana María Gómez
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal genetic arrhythmia that manifests syncope or sudden death in children and young adults under stress conditions. CPVT patients often present bradycardia and sino-atrial node (SAN) dysfunction. However, the mechanism remains unclear. We analyzed SAN function in two CPVT families and in a novel knock-in (KI) mouse model carrying the RyR2R420Q mutation. Humans and KI mice presented slower resting heart rate. Accordingly, the rate of spontaneous intracellular Ca2+ ([Ca2+]i) transients was slower in KI mouse SAN preparations than in WT, without any significant alteration in the "funny" current (If )...
April 20, 2017: JCI Insight
https://www.readbyqxmd.com/read/28413806/ryanodine-and-ip3-receptor-mediated-calcium-signaling-play-a-pivotal-role-in-neurological-infrared-laser-modulation
#3
Gleb P Tolstykh, Cory A Olsovsky, Bennett L Ibey, Hope T Beier
Pulsed infrared (IR) laser energy has been shown to modulate neurological activity through both stimulation and inhibition of action potentials. While the mechanism(s) behind this phenomenon is (are) not completely understood, certain hypotheses suggest that the rise in temperature from IR exposure could activate temperature- or pressure-sensitive ion channels or create pores in the cellular outer membrane, allowing an influx of typically plasma-membrane-impermeant ions. Studies using fluorescent intensity-based calcium ion ([Formula: see text]) sensitive dyes show changes in [Formula: see text] levels after various IR stimulation parameters, which suggests that [Formula: see text] may originate from the external solution...
April 2017: Neurophotonics
https://www.readbyqxmd.com/read/28405885/sudden-death-due-to-catecholaminergic-polymorphic-ventricular-tachycardia-following-negative-stress-test-outcome-genetics-and-clinical-implications
#4
Cristian D'Ovidio, Aldo Carnevale, Vincenzo M Grassi, Enrica Rosato, Bernat Del Olmo, Monica Coll, Oscar Campuzano, Anna Iglesias, Ramon Brugada, Antonio Oliva
This paper discusses the case of a young boy who died suddenly during a football match. The victim's personal and family medical histories were negative for cardiac events. He had undergone a cardiological investigation some months before his death, enabling him to participate in competitive sports. Only post-mortem molecular analysis allowed for a clearer determination of the most plausible cause of death, which was identified as inherited arrhythmogenic heart disease, known as catecholaminergic polymorphic ventricular tachycardia...
April 13, 2017: Forensic Science, Medicine, and Pathology
https://www.readbyqxmd.com/read/28404607/interpreting-incidentally-identified-variants-in-genes-associated-with-catecholaminergic-polymorphic-ventricular-tachycardia-in-a-large-cohort-of-clinical-whole-exome-genetic-test-referrals
#5
Andrew P Landstrom, Andrew L Dailey-Schwartz, Jill A Rosenfeld, Yaping Yang, Margaret J McLean, Christina Y Miyake, Santiago O Valdes, Yuxin Fan, Hugh D Allen, Daniel J Penny, Jeffrey J Kim
BACKGROUND: The rapid expansion of genetic testing has led to increased utilization of clinical whole-exome sequencing (WES). Clinicians and genetic researchers are being faced with assessing risk of disease vulnerability from incidentally identified genetic variants which is typified by variants found in genes associated with sudden death-predisposing catecholaminergic polymorphic ventricular tachycardia (CPVT). We sought to determine whether incidentally identified variants in genes associated with CPVT from WES clinical testing represent disease-associated biomarkers...
April 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28403410/assessing-the-pathogenicity-of-ryr1-variants-in-malignant-hyperthermia
#6
A Merritt, P Booms, M-A Shaw, D M Miller, C Daly, J G Bilmen, K M Stowell, P D Allen, D S Steele, P M Hopkins
Background: . Missense variants in the ryanodine receptor 1 gene ( RYR1 ) are associated with malignant hyperthermia but only a minority of these have met the criteria for use in predictive DNA diagnosis. We examined the utility of a simplified method of segregation analysis and a functional assay for determining the pathogenicity of recurrent RYR1 variants associated with malignant hyperthermia. Methods: . We identified previously uncharacterised RYR1 variants found in four or more malignant hyperthermia families and conducted simplified segregation analyses...
April 1, 2017: British Journal of Anaesthesia
https://www.readbyqxmd.com/read/28402838/exposure-of-honey-bees-apis-mellifera-to-different-classes-of-insecticides-exhibit-distinct-molecular-effect-patterns-at-concentrations-that-mimic-environmental-contamination
#7
Verena Christen, Karl Fent
Pesticides are implicated in the decline of honey bee populations. Many insecticides are neurotoxic and act by different modes of actions. Although a link between insecticide exposure and changed behaviour has been made, molecular effects underlying these effects are poorly understood. Here we elucidated molecular effects at environmental realistic concentrations of two organophosphates, chlorpyrifos and malathion, the pyrethroid cypermethrin, and the ryanodine receptor activator, chlorantraniliprole. We assessed transcriptional alterations of selected genes at three exposure times (24 h, 48 h, 72 h) in caged honey bees exposed to different concentrations of these compounds...
April 9, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28400318/hemopexin-counteracts-systolic-dysfunction-induced-by-heme-driven-oxidative-stress
#8
Giada Ingoglia, Can Martin Sag, Nikolai Rex, Lucia De Franceschi, Francesca Vinchi, James Cimino, Sara Petrillo, Stefan Wagner, Klaus Kreitmeier, Lorenzo Silengo, Fiorella Altruda, Lars S Maier, Emilio Hirsch, Alessandra Ghigo, Emanuela Tolosano
Heart failure is a leading cause of morbidity and mortality in patients affected by different disorders associated to intravascular hemolysis. The leading factor is the presence of pathologic amount of pro-oxidant free heme in the bloodstream, due to the exhaustion of the natural heme scavenger Hemopexin (Hx). Here, we evaluated whether free heme directly affects cardiac function, and tested the therapeutic potential of replenishing serum Hx for increasing serum heme buffering capacity. The effect of heme on cardiac function was assessed in vitro, on primary cardiomyocytes and H9c2 myoblast cell line, and in vivo, in Hx(-/-) mice and in genetic and acquired mouse models of intravascular hemolysis...
April 8, 2017: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/28390800/ca-2-release-via-two-pore-channel-type-2-tpc2-is-required-for-slow-muscle-cell-myofibrillogenesis-and-myotomal-patterning-in-intact-zebrafish-embryos
#9
Jeffrey J Kelu, Sarah E Webb, John Parrington, Antony Galione, Andrew L Miller
We recently demonstrated a critical role for two-pore channel type 2 (TPC2)-mediated Ca(2+) release during the differentiation of slow (skeletal) muscle cells (SMC) in intact zebrafish embryos, via the introduction of a translational-blocking morpholino antisense oligonucleotide (MO). Here, we extend our study and demonstrate that knockdown of TPC2 with a non-overlapping splice-blocking MO, knockout of TPC2 (via the generation of a tpcn2(dhkz1a) mutant line of zebrafish using CRISPR/Cas9 gene-editing), or the pharmacological inhibition of TPC2 action with bafilomycin A1 or trans-ned-19, also lead to a significant attenuation of SMC differentiation, characterized by a disruption of SMC myofibrillogenesis and gross morphological changes in the trunk musculature...
April 6, 2017: Developmental Biology
https://www.readbyqxmd.com/read/28389603/the-impact-of-ryr2-potentiation-on-myocardial-function
#10
Elena Lascano, Jorge A Negroni, Martin Vila Petroff, Alicia Mattiazzi
This perspective attempts to shed light on an old and not yet solved controversy in cardiac physiology, i.e. the impact of increasing RyR2 open probability on myocardial function. Based on an already proved myocyte model, it is shown that increasing RyR2 open probability results in a purely short-lived increase in Ca(2+) transient amplitude, and therefore it does not increase cardiac contractility. However, potentiation of RyR2 activity permanently enhances fractional Ca(2+) release, shifting the intracellular Ca(2+) transient vs SR Ca(2+) content curve to a new state of higher efficiency...
April 7, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28387457/dampened-activity-of-ryanodine-receptor-channels-in-mutant-skeletal-muscle-lacking-tric-a
#11
Sam El-Ajouz, Elisa Venturi, Katja Witschas, Matthew Beech, Abigail D Wilson, Chris Lindsay, David Eberhardt, Fiona O'Brien, Tsunaki Iida, Miyuki Nishi, Hiroshi Takeshima, Rebecca Sitsapesan
TRIC-A is a major component of the nuclear and sarcoplasmic reticulum (SR) membranes of cardiac and skeletal muscle, and is localised closely with RyR channels in the SR terminal cisternae. The skeletal muscle of Tric-a KO mice is characterised by Ca(2+) overloaded and swollen SR and by changes in the properties of SR Ca(2+) release. We therefore investigated if RyR1 gating behaviour is modified in the SR from Tric-a KO mice by incorporating native RyR1 into planar phospholipid bilayers under voltage-clamp conditions...
April 7, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28384221/kchip2-regulates-the-cardiac-ca2-transient-and-myocyte-contractility-by-targeting-ryanodine-receptor-activity
#12
Drew M Nassal, Xiaoping Wan, Haiyan Liu, Kenneth R Laurita, Isabelle Deschênes
Pathologic electrical remodeling and attenuated cardiac contractility are featured characteristics of heart failure. Coinciding with these remodeling events is a loss of the K+ channel interacting protein, KChIP2. While, KChIP2 enhances the expression and stability of the Kv4 family of potassium channels, leading to a more pronounced transient outward K+ current, Ito,f, the guinea pig myocardium is unique in that Kv4 expression is absent, while KChIP2 expression is preserved, suggesting alternative consequences to KChIP2 loss...
2017: PloS One
https://www.readbyqxmd.com/read/28374413/beneficial-effects-of-leptin-treatment-in-a-setting-of-cardiac-dysfunction-induced-by-transverse-aortic-constriction-in-mouse
#13
Nieves Gómez-Hurtado, Alejandro Domínguez-Rodríguez, Philippe Mateo, Maria Fernandez-Velasco, Almudena Val-Blasco, Rafael Aizpún, Jessica Sabourin, Ana Maria Gómez, Jean-Pierre Benitah, Carmen Delgado
KEY POINTS: Leptin, is a 16 kDa pleiotropic peptide, primary secreted by adipocytes, but also produced by other tissues including the heart. Controversy exists regarding the adverse and beneficial effects of Leptin on the heart We analysed the effect of a non-hypertensive dose of leptin on cardiac function, [Ca(2+) ]i handling and cellular electrophysiology, which participate in the genesis of pump failure and related arrhythmias both in control mice and in mice subjected to chronic pressure-overload by transverse aorta constriction We find that Leptin activates mechanisms that contribute to cardiac dysfunction in physiological conditions...
April 4, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28373957/comparative-study-the-expression-of-calcium-cycling-genes-in-bombay-duck-harpadon-nehereus-and-beltfish-trichiurus-lepturus-with-different-swimming-activities
#14
Hui Zhang, Gilbert Audira, Yuan Li, Weiwei Xian, Muhammed Muhsin Varikkodan, Chung-Der Hsiao
The contraction and relaxation events of the muscle is mediated by the coordination of many important calcium cycling proteins of ryanodine receptor (RYR), troponin C (TNNC), parvalbumin (PVALB), sarcoendoplasmic reticulum calcium transport ATPase (SERCA) and calsequestrin (CASQ). In higher vertebrates, the expression level of calcium cycling proteins are positively correlated to the muscle contraction/relaxation ability of the cell. In this study, we used RNAseq to explore the expression profile of calcium cycling genes between two marine fish of Bombay duck (Harpadon nehereus) and beltfish (Trichiurus lepturus) with poor and robust swimming activities, respectively...
June 2017: Genomics Data
https://www.readbyqxmd.com/read/28373535/dantrolene-requires-mg-2-to-arrest-malignant-hyperthermia
#15
Rocky H Choi, Xaver Koenig, Bradley S Launikonis
Malignant hyperthermia (MH) is a clinical syndrome of skeletal muscle that presents as a hypermetabolic response to volatile anesthetic gases, where susceptible persons may develop lethally high body temperatures. Genetic predisposition mainly arises from mutations on the skeletal muscle ryanodine receptor (RyR). Dantrolene is administered to alleviate MH symptoms, but its mechanism of action and its influence on the Ca(2+) transients elicited by MH triggers are unknown. Here, we show that Ca(2+) release in the absence of Mg(2+) is unaffected by the presence of dantrolene but that dantrolene becomes increasingly effective as cytoplasmic-free [Mg(2+)] (free [Mg(2+)]cyto) passes mM levels...
April 3, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28370799/through-modulation-of-cardiac-ca-2-handling-ucp2-affects-cardiac-electrophysiology-and-influences-the-susceptibility-for-ca-2-mediated-arrhythmias
#16
Robert Larbig, Sara Reda, Vera Paar, Andrea Trost, Johannes Leitner, Stephanie Weichselbaumer, Karolina A Motloch, Bernhard Wernly, Andreas Arrer, Benjamin Strauss, Michael Lichtenauer, Herbert A Reitsamer, Lars Eckardt, Guiscard Seebohm, Uta C Hoppe, Lukas J Motloch
Introduction UCP2 belongs to a superfamily of mitochondrial ion transporters. Due to its beneficial influence on production of reactive oxygen species it is suggested to reduce cardiac ischemic reperfusion injury. Recent studies uncovered its ability to regulate mitochondrial Ca(2+) -uptake and therefore to influence cardiac cytosolic Ca(2+) -handling, indicating compensatory pathways to avoid toxic Ca(2+) -overload in UCP2 knock-out mice (UCP2(-/-) ). However, the specific mechanisms and their impact on cardiac electrophysiology remain speculative...
March 31, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/28370211/a-protocol-for-registration-and-correction-of-multicolour-sted-superresolution-images
#17
E Hebisch, E Wagner, V Westphal, J J Sieber, S E Lehnart
Multicolour fluorescence imaging by STimulated Emission Depletion (STED) superresolution microscopy with doughnut-shaped STED laser beams based on different wavelengths for each colour channel requires precise image registration. This is especially important when STED imaging is used for co-localisation studies of two or more native proteins in biological specimens to analyse nanometric subcellular spatial arrangements. We developed a robust postprocessing image registration protocol, with the aim to verify and ultimately optimise multicolour STED image quality...
April 3, 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28369767/multiple-targets-for-flecainide-action-implications-for-cardiac-arrhythmogenesis
#18
REVIEW
Samantha C Salvage, Karthik H Chandrasekharan, Kamalan Jeevaratnam, Angela F Dulhunty, Andrew J Thompson, Antony P Jackson, Christopher L-H Huang
Flecainide suppresses cardiac tachyarrhythmias including paroxysmal atrial fibrillation, supraventricular tachycardia, arrhythmic long QT syndromes (LQTS), as well as the Ca(2+) -mediated, catecholaminergic polymorphic ventricular, tachycardia (CPVT). However, flecainide can also exert pro-arrhythmic effects most notably following myocardial infarction and when used to diagnose Brugada Syndrome (BrS). These divergent actions result from its physiological and pharmacological actions at multiple, interacting, levels of cellular organisation...
April 3, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28364296/juvenile-onset-myasthenia-gravis-autoantibody-status-clinical-characteristics-and-genetic-polymorphisms
#19
Yu Hong, Geir Olve Skeie, Paraskevi Zisimopoulou, Katerina Karagiorgou, Socrates J Tzartos, Xiang Gao, Yao-Xian Yue, Fredrik Romi, Xu Zhang, Hai-Feng Li, Nils Erik Gilhus
Myasthenia gravis (MG) is an autoimmune disorder mediated by antibodies against proteins at the neuromuscular junction. Juvenile-onset MG (JMG) has been reported to have special characteristics. It is still unclear whether there are any pathogenic and genetic differences between juvenile and adult MG. In this study, we evaluated the clinical characteristics, autoantibody status (antibodies against AChR, MuSK, LRP4, titin and RyR) and genetic susceptibility (CHRNA1, CTLA4 and AIRE) in 114 Chinese JMG patients, and compared with 207 young adult MG patients (onset age 18-40 years)...
March 31, 2017: Journal of Neurology
https://www.readbyqxmd.com/read/28359509/autosomal-recessive-cardiomyopathy-presenting-as-acute-myocarditis
#20
Serkan Belkaya, Amy R Kontorovich, Minji Byun, Sonia Mulero-Navarro, Fanny Bajolle, Aurelie Cobat, Rebecca Josowitz, Yuval Itan, Raphaelle Quint, Lazaro Lorenzo, Soraya Boucherit, Cecile Stoven, Sylvie Di Filippo, Laurent Abel, Shen-Ying Zhang, Damien Bonnet, Bruce D Gelb, Jean-Laurent Casanova
BACKGROUND: Myocarditis is inflammation of the heart muscle that can follow various viral infections. Why children only rarely develop life-threatening acute viral myocarditis (AVM), given that the causal viral infections are common, is unknown. Genetic lesions might underlie such susceptibilities. Mouse genetic studies demonstrated that interferon (IFN)-α/β immunity defects increased susceptibility to virus-induced myocarditis. Moreover, variations in human TLR3, a potent inducer of IFNs, were proposed to underlie AVM...
April 4, 2017: Journal of the American College of Cardiology
keyword
keyword
103332
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"