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Anna Szewczyk, Julie Gehl, Malgorzata Daczewska, Jolanta Saczko, Stine Krog Frandsen, Julita Kulbacka
Calcium electroporation (CaEP) describes the use of electric pulses (electroporation) to transiently permeabilize cells to allow supraphysiological doses of calcium to enter the cytosol. Calcium electroporation has successfully been investigated for treatment of cutaneous metastases in a clinical study. This preclinical study explores the possible use of calcium electroporation for treatment of sarcoma. A normal murine muscle cell line (C2C12), and a human rhabdomyosarcoma cell line (RD) were used in the undifferentiated and differentiated state...
February 20, 2018: Oncotarget
Dilyana Filipova, Margit Henry, Tamara Rotshteyn, Anna Brunn, Mariana Carstov, Martina Deckert, Jürgen Hescheler, Agapios Sachinidis, Gabriele Pfitzer, Symeon Papadopoulos
In skeletal muscle the coordinated actions of two mechanically coupled Ca2+ channels-the 1,4-dihydropyridine receptor (Cav1.1) and the type 1 ryanodine receptor (RYR1)-underlie the molecular mechanism of rapid cytosolic [Ca2+] increase leading to contraction. While both [Ca2+]i and contractile activity have been implicated in the regulation of myogenesis, less is known about potential specific roles of Cav1.1 and RYR1 in skeletal muscle development. In this study, we analyzed the histology and the transcriptomic changes occurring at E14...
2018: PloS One
Y Nilipour, S Nafissi, A E Tjust, G Ravenscroft, H Hossein-Nejad, R Taylor, V Varasteh, F Pedrosa Domellöf, M Zangi, S H Tonekaboni, M Olivé, K Kiiski, L Sagath, Davis, N Laing, H Tajsharghi
BACKGROUND: Nemaline myopathy has been associated with mutations in twelve genes to date. However, for some patients diagnosed with nemaline myopathy, definitive mutations are not identified in the known genes, suggesting there are other genes involved. This study describes compound heterozygosity for rare variants in RYR3 in one such patient. RESULTS: Clinical examination of the patient at 22 years of age revealed a long-narrow face, high arched palate and bilateral facial weakness...
March 2, 2018: European Journal of Neurology: the Official Journal of the European Federation of Neurological Societies
Alexander Polster, Benjamin R Nelson, Symeon Papadopoulos, Eric N Olson, Kurt G Beam
In skeletal muscle, residues 720-764/5 within the CaV 1.1 II-III loop form a critical domain that plays an essential role in transmitting the excitation-contraction (EC) coupling Ca2+ release signal to the type 1 ryanodine receptor (RyR1) in the sarcoplasmic reticulum. However, the identities of proteins that interact with the loop and its critical domain and the mechanism by which the II-III loop regulates RyR1 gating remain unknown. Recent work has shown that EC coupling in skeletal muscle of fish and mice depends on the presence of Stac3, an adaptor protein that is highly expressed only in skeletal muscle...
February 21, 2018: Journal of General Physiology
Diana A van der Plaat, Kim de Jong, Maaike de Vries, Cleo C van Diemen, Ivana Nedeljković, Najaf Amin, Hans Kromhout, Roel Vermeulen, Dirkje S Postma, Cornelia M van Duijn, H Marike Boezen, Judith M Vonk
OBJECTIVES: Occupational pesticide exposure is associated with a wide range of diseases, including lung diseases, but it is largely unknown how pesticides influence airway disease pathogenesis. A potential mechanism might be through epigenetic mechanisms, like DNA methylation. Therefore, we assessed associations between occupational exposure to pesticides and genome-wide DNA methylation sites. METHODS: 1561 subjects of LifeLines were included with either no (n=1392), low (n=108) or high (n=61) exposure to any type of pesticides (estimated based on current or last held job)...
February 19, 2018: Occupational and Environmental Medicine
Nafi Dilaver, Neda Mazaheri, Reza Maroofian, Jawaher Zeighami, Tahere Seifi, Mina Zamani, Alireza Sedaghat, Gholam Reza Shariati, Hamid Galehdari
Ryanodine receptor 1 ( RYR1 ) is an intracellular calcium receptor primarily expressed in skeletal muscle with a role in excitation contraction. Both dominant and recessive mutations in the RYR1 gene cause a range of RYR1 -related myopathies and/or susceptibility to malignant hyperthermia (MH). Recently, an atypical manifestation of ptosis, variably presenting with ophthalmoplegia, facial paralysis, and scoliosis but without significant muscle weakness, has been reported in 9 cases from 4 families with bialleic variants in RYR1 ...
December 2017: Molecular Syndromology
Andreas J W Hartel, Peijie Ong, Indra Schroeder, M Hunter Giese, Siddharth Shekar, Oliver B Clarke, Ran Zalk, Andrew R Marks, Wayne A Hendrickson, Kenneth L Shepard
Single-channel recordings are widely used to explore functional properties of ion channels. Typically, such recordings are performed at bandwidths of less than 10 kHz because of signal-to-noise considerations, limiting the temporal resolution available for studying fast gating dynamics to greater than 100 µs. Here we present experimental methods that directly integrate suspended lipid bilayers with high-bandwidth, low-noise transimpedance amplifiers based on complementary metal-oxide-semiconductor (CMOS) integrated circuits (IC) technology to achieve bandwidths in excess of 500 kHz and microsecond temporal resolution...
February 5, 2018: Proceedings of the National Academy of Sciences of the United States of America
Heinz Jungbluth, Susan Treves, Francesco Zorzato, Anna Sarkozy, Julien Ochala, Caroline Sewry, Rahul Phadke, Mathias Gautel, Francesco Muntoni
The congenital myopathies are a group of early-onset, non-dystrophic neuromuscular conditions with characteristic muscle biopsy findings, variable severity and a stable or slowly progressive course. Pronounced weakness in axial and proximal muscle groups is a common feature, and involvement of extraocular, cardiorespiratory and/or distal muscles can implicate specific genetic defects. Central core disease (CCD), multi-minicore disease (MmD), centronuclear myopathy (CNM) and nemaline myopathy were among the first congenital myopathies to be reported, and they still represent the main diagnostic categories...
February 2, 2018: Nature Reviews. Neurology
Daphne Wy Li, Poh San Lai, Delice W Lee, Rita Yy Yong, Tat Leang Lee
INTRODUCTION: Sporadic clinical episodes of malignant hyperthermia (MH) that develop during general anaesthesia (GA) have been reported in Singapore. However, there is no published local report of a confirmed case of MH susceptibility (MHS) by skeletal muscle contracture tests and/or molecular tests. MATERIALS AND METHODS: We report 2 patients from an extended family who developed signs of clinical MH while under GA. The MH episodes were successfully treated with intravenous dantrolene sodium...
December 2017: Annals of the Academy of Medicine, Singapore
Takashi Kondo, Toshimichi Yasuda, Keiko Mukaida, Sachiko Otsuki, Rieko Kanzaki, Hirotsugu Miyoshi, Hiroshi Hamada, Ichizo Nishino, Masashi Kawamoto
PURPOSE: The aim of this study was to analyze the genetic and functional role of a novel RYR1 variant c.251 C > T (p.Thr84Met) identified in a patient with muscle weakness demonstrating MH susceptibility. METHODS: DNA testing of family members was conducted for assessment of pathogenicity of the genetic variant. For functional analysis, Ca2+ measurement using patient-derived myotubes and p.Thr84Met RYR1-transfected human embryonic kidney (HEK)-293 cells was performed to evaluate reactivity to RYR1 activators...
January 17, 2018: Journal of Anesthesia
Angela J Gaboardi, Jochen Kressler, Teresa K Snow, Edward M Balog
INTRODUCTION: Because impaired excitation-contraction coupling and reduced sarcoplasmic reticulum Ca2+ release may contribute to the age-associated decline in skeletal muscle strength, we investigated the effect of aging on RyR1 regulation by physiological channel ligands. METHODS: [3 H]Ryanodine binding to membranes from 8 and 26 month old Fischer 344 extensor digitorum longus (EDL) and soleus muscles was used to investigate the effects of age on RyR1 modulation by Ca2+ and calmodulin (CaM)...
January 9, 2018: Muscle & Nerve
Jeanne Lainé, Gunnar Skoglund, Emmanuel Fournier, Nacira Tabti
BACKGROUND: Human induced pluripotent stem cells-derived myogenic progenitors develop functional and ultrastructural features typical of skeletal muscle when differentiated in culture. Besides disease-modeling, such a system can be used to clarify basic aspects of human skeletal muscle development. In the present study, we focus on the development of the excitation-contraction (E-C) coupling, a process that is essential both in muscle physiology and as a tool to differentiate between the skeletal and cardiac muscle...
January 5, 2018: Skeletal Muscle
Emma Matthews, Christoph Neuwirth, Fatima Jaffer, Renata S Scalco, Doreen Fialho, Matt Parton, Dipa Raja Rayan, Karen Suetterlin, Richa Sud, Roland Spiegel, Rachel Mein, Henry Houlden, Andrew Schaefer, Estelle Healy, Jacqueline Palace, Ros Quinlivan, Susan Treves, Janice L Holton, Heinz Jungbluth, Michael G Hanna
OBJECTIVE: To characterize the phenotype of patients with symptoms of periodic paralysis (PP) and ryanodine receptor (RYR1) gene mutations. METHODS: Cases with a possible diagnosis of PP but additional clinicopathologic findings previously associated with RYR1-related disorders were referred for a tertiary neuromuscular clinical assessment in which they underwent detailed clinical evaluation, including neurophysiologic assessment, muscle biopsy, and muscle MRI. Genetic analysis with next-generation sequencing and/or targeted Sanger sequencing was performed...
January 30, 2018: Neurology
Alexander Polster, Stefano Perni, Dilyana Filipova, Ong Moua, Joshua D Ohrtman, Hicham Bichraoui, Kurt G Beam, Symeon Papadopoulos
The type 1 ryanodine receptor (RyR1) in skeletal muscle is a homotetrameric protein that releases Ca2+ from the sarcoplasmic reticulum (SR) in response to an "orthograde" signal from the dihydropyridine receptor (DHPR) in the plasma membrane (PM). Additionally, a "retrograde" signal from RyR1 increases the amplitude of the Ca2+ current produced by CaV1.1, the principle subunit of the DHPR. This bidirectional signaling is thought to depend on physical links, of unknown identity, between the DHPR and RyR1. Here, we investigate whether the isolated cytoplasmic domain of RyR1 can interact structurally or functionally with CaV1...
December 28, 2017: Journal of General Physiology
Elisa Venturi, Chris Lindsay, Sabine Lotteau, Zhaokang Yang, Emma Steer, Katja Witschas, Abigail D Wilson, James R Wickens, Angela J Russell, Derek Steele, Sarah Calaghan, Rebecca Sitsapesan
BACKGROUND AND PURPOSE: Statins are amongst the most widely prescribed drugs for those at risk of cardiovascular disease, lowering cholesterol levels by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Although effective in prevention of cardiovascular disease, statin use is associated with muscle weakness, myopathies and, in rare cases, fatal rhabdomyolysis. As simvastatin, a commonly prescribed statin, can promote Ca2+ release from sarcoplasmic reticulum (SR) vesicles, we investigated if simvastatin could directly activate skeletal (RyR1) and cardiac (RyR2) ryanodine receptors...
December 26, 2017: British Journal of Pharmacology
Sarah Boissel, Catherine Fallet-Bianco, David Chitayat, Valérie Kremer, Christina Nassif, Françoise Rypens, Marie-Ange Delrue, Dorothée Dal Soglio, Luc L Oligny, Natalie Patey, Elisabeth Flori, Mireille Cloutier, David Dyment, Philippe Campeau, Aspasia Karalis, Sonia Nizard, William D Fraser, François Audibert, Emmanuelle Lemyre, Guy A Rouleau, Fadi F Hamdan, Zoha Kibar, Jacques L Michaud
PurposeFetal anomalies represent a poorly studied group of developmental disorders. Our objective was to assess the impact of whole-exome sequencing (WES) on the investigation of these anomalies.MethodsWe performed WES in 101 fetuses or stillborns who presented prenatally with severe anomalies, including renal a/dysgenesis, VACTERL association (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities), brain anomalies, suspected ciliopathies, multiple major malformations, and akinesia...
October 26, 2017: Genetics in Medicine: Official Journal of the American College of Medical Genetics
Alberto Zullo, Martin Textor, Philipp Elischer, Stefan Mall, Andreas Alt, Werner Klingler, Werner Melzer
Malignant hyperthermia (MH) is a fatal hypermetabolic state that may occur during general anesthesia in susceptible individuals. It is often caused by mutations in the ryanodine receptor RyR1 that favor drug-induced release of Ca2+ from the sarcoplasmic reticulum. Here, knowing that membrane depolarization triggers Ca2+ release in normal muscle function, we study the cross-influence of membrane potential and anesthetic drugs on Ca2+ release. We used short single muscle fibers of knock-in mice heterozygous for the RyR1 mutation Y524S combined with microfluorimetry to measure intracellular Ca2+ signals...
December 15, 2017: Journal of General Physiology
Stefano Perni, Manuela Lavorato, Kurt G Beam
Skeletal muscle contraction is triggered by Ca2+ release from the sarcoplasmic reticulum (SR) in response to plasma membrane (PM) excitation. In vertebrates, this depends on activation of the RyR1 Ca2+ pore in the SR, under control of conformational changes of CaV 1.1, located ∼12 nm away in the PM. Over the last ∼30 y, gene knockouts have revealed that CaV 1.1/RyR1 coupling requires additional proteins, but leave open the possibility that currently untested proteins are also necessary. Here, we demonstrate the reconstitution of conformational coupling in tsA201 cells by expression of CaV 1...
December 26, 2017: Proceedings of the National Academy of Sciences of the United States of America
C Anandan, M A Cipriani, R S Laughlin, Z Niu, M Milone
BACKGROUND AND PURPOSE: CACNA1S encodes Cav 1.1, a voltage sensor for muscle excitation-contraction coupling, which activates the ryanodine receptor 1 (RYR1) leading to calcium release from the sarcoplasmic reticulum. CACNA1S mutations cause hypokalemic periodic paralysis, malignant hyperthermia and congenital myopathy. RYR1 mutations result in congenital myopathy, malignant hyperthermia and rhabdomyolysis. METHODS: The aim was to describe a novel phenotype associated with a CACNA1S variant at a site previously linked to hypokalemic periodic paralysis...
February 2018: European Journal of Neurology: the Official Journal of the European Federation of Neurological Societies
Ruple S Laughlin, Zhiyv Niu, Eric Wieben, Margherita Milone
BACKGROUND: Congenital myopathies due to ryanodine receptor (RYR1) mutations are increasingly identified and correlate with a wide range of phenotypes, most commonly that of malignant hyperthermia susceptibility and central cores on muscle biopsy with rare reports of distal muscle weakness, but in the setting of early onset global weakness. METHODS: We report a case of a patient presenting with childhood onset hand stiffness and adult onset progressive hand weakness and jaw contractures discovered to have two variants in the RYR1 gene...
November 2017: Molecular Genetics & Genomic Medicine
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