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Richardson SJ, Thekkedam CG, Casarotto MG, Beard NA, Dulhunty AF. FKBP12 binds to the cardiac ryanodine receptor with negative cooperativity: implications for heart muscle physiology in health and disease. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220169. [PMID: 37122219 PMCID: PMC10150220 DOI: 10.1098/rstb.2022.0169] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Cardiac ryanodine receptors (RyR2) release the Ca2+ from intracellular stores that is essential for cardiac myocyte contraction. The ion channel opening is tightly regulated by intracellular factors, including the FK506 binding proteins, FKBP12 and FKBP12.6. The impact of these proteins on RyR2 activity and cardiac contraction is debated, with often apparently contradictory experimental results, particularly for FKBP12. The isoform that regulates RyR2 has generally been considered to be FKBP12.6, despite the fact that FKBP12 is the major isoform associated with RyR2 in some species and is bound in similar proportions to FKBP12.6 in others, including sheep and humans. Here, we show time- and concentration-dependent effects of adding FKBP12 to RyR2 channels that were partly depleted of FKBP12/12.6 during isolation. The added FKBP12 displaced most remaining endogenous FKBP12/12.6. The results suggest that FKBP12 activates RyR2 with high affinity and inhibits RyR2 with lower affinity, consistent with a model of negative cooperativity in FKBP12 binding to each of the four subunits in the RyR tetramer. The easy dissociation of some FKBP12/12.6 could dynamically alter RyR2 activity in response to changes in in vivo regulatory factors, indicating a significant role for FKBP12/12.6 in Ca2+ signalling and cardiac function in healthy and diseased hearts. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- S J Richardson
- John Curtin School of Medical Research, Australian National University, Canberra, Australia, Australian Capital Territory 2601, Australia
| | - C G Thekkedam
- John Curtin School of Medical Research, Australian National University, Canberra, Australia, Australian Capital Territory 2601, Australia
| | - M G Casarotto
- John Curtin School of Medical Research, Australian National University, Canberra, Australia, Australian Capital Territory 2601, Australia
| | - N A Beard
- John Curtin School of Medical Research, Australian National University, Canberra, Australia, Australian Capital Territory 2601, Australia
| | - A F Dulhunty
- John Curtin School of Medical Research, Australian National University, Canberra, Australia, Australian Capital Territory 2601, Australia
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2
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She J, Guo J, Jiang Y. Structure and Function of Plant and Mammalian TPC Channels. Handb Exp Pharmacol 2023; 278:155-180. [PMID: 35879575 DOI: 10.1007/164_2022_599] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Two-pore channels (TPCs) belong to the family of voltage-gated tetrameric cation channels and are ubiquitously expressed in organelles of animals and plants. These channels are believed to be evolutionary intermediates between homotetrameric voltage-gated potassium/sodium channels and the four-domain, single subunit, voltage-gated sodium/calcium channels. Each TPC subunit contains 12 transmembrane segments that can be divided into two homologous copies of an S1-S6 Shaker-like 6-TM domain. A functional TPC channel assembles as a dimer - the equivalent of a voltage-gated tetrameric cation channel. The plant TPC channel is localized in the vacuolar membrane and is also called the SV channel for generating the slow vacuolar (SV) current observed long before its molecular identification. Three subfamilies of mammalian TPC channels have been defined - TPC1, 2, and 3 - with the first two being ubiquitously expressed in animals and TPC3 being expressed in some animals but not in humans. Mammalian TPC1 and TPC2 are localized to the endolysosomal membrane and their functions are associated with various physiological processes. TPC3 is localized in the plasma membrane and its physiological function is not well defined.
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Affiliation(s)
- Ji She
- MOE Key Laboratory for Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jiangtao Guo
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Department of Neurology, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Youxing Jiang
- Howard Hughes Medical Institute, Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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3
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Badin JK, Eggenberger C, Rodenbeck SD, Hashmi ZA, Wang IW, Garcia JP, Alloosh M, Sturek M. Intracellular Ca 2+ Dysregulation in Coronary Smooth Muscle Is Similar in Coronary Disease of Humans and Ossabaw Miniature Swine. J Cardiovasc Transl Res 2022; 15:167-178. [PMID: 34286469 PMCID: PMC10620470 DOI: 10.1007/s12265-021-10153-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 07/02/2021] [Indexed: 12/31/2022]
Abstract
Intracellular free Ca2+ ([Ca2+]i) dysregulation occurs in coronary smooth muscle (CSM) in atherosclerotic coronary artery disease (CAD) of metabolic syndrome (MetS) swine. Our goal was to determine how CAD severity, arterial structure, and MetS risk factors associate with [Ca2+]i dysregulation in human CAD compared to changes in Ossabaw miniature swine. CSM cells were dispersed from coronary arteries of explanted hearts from transplant recipients and from lean and MetS swine with CAD. CSM [Ca2+]i elicited by Ca2+ influx and sarcoplasmic reticulum (SR) Ca2+ release and sequestration was measured with fura-2. Increased [Ca2+]i signaling was associated with advanced age and a greater media area in human CAD. Decreased [Ca2+]i signaling was associated with a greater number of risk factors and a higher plaque burden in human and swine CAD. Similar [Ca2+]i dysregulation exhibited in human and Ossabaw swine CSM provides strong evidence for the translational relevance of this large animal model.
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Affiliation(s)
- Jill K Badin
- Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Sciences, Room 385, Indianapolis, IN, 46202, USA
| | - Caleb Eggenberger
- Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Sciences, Room 385, Indianapolis, IN, 46202, USA
- Marian University College of Osteopathic Medicine, Indianapolis, IN, 46222, USA
| | - Stacey Dineen Rodenbeck
- Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Sciences, Room 385, Indianapolis, IN, 46202, USA
- Department of Biology, Harding University, Searcy, AR, 72149, USA
| | - Zubair A Hashmi
- Cardiothoracic Transplantation Surgery, Indiana University - Methodist Hospital, Indianapolis, IN, 46202, USA
| | - I-Wen Wang
- Cardiothoracic Transplantation Surgery, Indiana University - Methodist Hospital, Indianapolis, IN, 46202, USA
| | - Jose P Garcia
- Cardiothoracic Transplantation Surgery, Indiana University - Methodist Hospital, Indianapolis, IN, 46202, USA
| | - Mouhamad Alloosh
- Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Sciences, Room 385, Indianapolis, IN, 46202, USA
| | - Michael Sturek
- Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Sciences, Room 385, Indianapolis, IN, 46202, USA.
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4
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Casas J, Meana C, López-López JR, Balsinde J, Balboa MA. Lipin-1-derived diacylglycerol activates intracellular TRPC3 which is critical for inflammatory signaling. Cell Mol Life Sci 2021; 78:8243-8260. [PMID: 34757442 PMCID: PMC8629864 DOI: 10.1007/s00018-021-03999-0] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 09/28/2021] [Accepted: 10/14/2021] [Indexed: 11/18/2022]
Abstract
Exposure to Gram-negative bacterial LPS exacerbates host immune responses and may lead to sepsis, a life-threatening condition. Despite its high mortality and morbidity, no drugs specifically directed to treating sepsis are currently available. Using human cell genetic depletion, pharmacological inhibition, live-cell microscopy and organelle-targeted molecular sensors we present evidence that the channel TRPC3 is activated intracellularly during macrophage exposure to LPS and is essential for Ca2+ release from internal stores. In this manner, TRPC3 participates in cytosolic Ca2+ elevations, activation of the transcription factor NF-κB and cytokine upregulation. We also report that TRPC3 is activated by diacylglycerol generated by the phosphatidic acid phosphatase lipin-1. In accord with this, lipin-1-deficient cells exhibit reduced Ca2+ responses to LPS challenge. Finally, pharmacological inhibition of TRPC3 reduces systemic inflammation induced by LPS in mice. Collectively, our study unveils a central component of LPS-triggered Ca2+ signaling that involves intracellular sensing of lipin-1-derived DAG by TRPC3, and opens new opportunities for the development of strategies to treat LPS-driven inflammation.
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Affiliation(s)
- Javier Casas
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain. .,Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Universidad de Valladolid, 47003, Valladolid, Spain.
| | - Clara Meana
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029, Madrid, Spain
| | - José Ramón López-López
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.,Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Universidad de Valladolid, 47003, Valladolid, Spain
| | - Jesús Balsinde
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029, Madrid, Spain
| | - María A Balboa
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain. .,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029, Madrid, Spain.
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5
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Percivale G, Angelini C, Falugi C, Picco C, Prestipino G. Time-dependent expression of ryanodine receptors in sea urchin eggs, zygotes and early embryos. ZYGOTE 2021;:1-4. [PMID: 34315559 DOI: 10.1017/S0967199421000514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this work, the presence of calcium-dependent calcium channels and their receptors (RyR) has been investigated in Paracentrotus lividus eggs and early embryos, from unfertilized egg to four-blastomere stages. Electrophysiological recordings of RyR single-channel current fluctuations showed that RyRs are functional during the first developmental events with a maximum at zygote stage, c. 40 min after fertilization, corresponding to the first cleavage. The nature of vertebrate-like RyRs active at this stage was established by specific activation/blockade experiments.
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6
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Demydenko K, Sipido KR, Roderick HL. Ca2+ release via InsP3Rs enhances RyR recruitment during Ca2+ transients by increasing dyadic [Ca2+] in cardiomyocytes. J Cell Sci 2021; 134:269146. [PMID: 34125209 DOI: 10.1242/jcs.258671] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 03/24/2021] [Accepted: 06/08/2021] [Indexed: 11/20/2022] Open
Abstract
Excitation-contraction coupling (ECC) relies on temporally synchronized sarcoplasmic reticulum (SR) Ca2+ release via ryanodine receptors (RyRs) at dyadic membrane compartments. Neurohormones, such as endothelin-1 (ET-1), that act via Gαq-associated G protein-coupled receptors (GPCRs) modulate Ca2+ dynamics during ECC and induce SR Ca2+ release events involving Ca2+ release via inositol 1,4,5-trisphosphate (InsP3) receptors (InsP3Rs). How the relatively modest Ca2+ release via InsP3Rs elicits this action is not resolved. Here, we investigated whether the actions of InsP3Rs on Ca2+ handling during ECC were mediated by a direct influence on dyadic Ca2+ levels and whether this mechanism contributes to the effects of ET-1. Using a dyad-targeted genetically encoded Ca2+ reporter, we found that InsP3R activation augmented dyadic Ca2+ fluxes during Ca2+ transients and increased Ca2+ sparks. RyRs were required for these effects. These data provide the first direct demonstration of GPCR and InsP3 effects on dyadic Ca2+, and support the notion that Ca2+ release via InsP3Rs influences Ca2+ transients during ECC by facilitating the activation and recruitment of proximal RyRs. We propose that this mechanism contributes to neurohormonal modulation of cardiac function. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Kateryna Demydenko
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000, Leuven, Belgium
| | - Karin R Sipido
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000, Leuven, Belgium
| | - H Llewelyn Roderick
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000, Leuven, Belgium
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7
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Blatter LA, Kanaporis G, Martinez-Hernandez E, Oropeza-Almazan Y, Banach K. Excitation-contraction coupling and calcium release in atrial muscle. Pflugers Arch 2021; 473:317-329. [PMID: 33398498 DOI: 10.1007/s00424-020-02506-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 09/28/2020] [Revised: 12/03/2020] [Accepted: 12/16/2020] [Indexed: 01/02/2023]
Abstract
In cardiac muscle, the process of excitation-contraction coupling (ECC) describes the chain of events that links action potential induced myocyte membrane depolarization, surface membrane ion channel activation, triggering of Ca2+ induced Ca2+ release from the sarcoplasmic reticulum (SR) Ca2+ store to activation of the contractile machinery that is ultimately responsible for the pump function of the heart. Here we review similarities and differences of structural and functional attributes of ECC between atrial and ventricular tissue. We explore a novel "fire-diffuse-uptake-fire" paradigm of atrial ECC and Ca2+ release that assigns a novel role to the SR SERCA pump and involves a concerted "tandem" activation of the ryanodine receptor Ca2+ release channel by cytosolic and luminal Ca2+. We discuss the contribution of the inositol 1,4,5-trisphosphate (IP3) receptor Ca2+ release channel as an auxiliary pathway to Ca2+ signaling, and we review IP3 receptor-induced Ca2+ release involvement in beat-to-beat ECC, nuclear Ca2+ signaling, and arrhythmogenesis. Finally, we explore the topic of electromechanical and Ca2+ alternans and its ramifications for atrial arrhythmia.
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Affiliation(s)
- L A Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA.
| | - G Kanaporis
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - E Martinez-Hernandez
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - Y Oropeza-Almazan
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - K Banach
- Department of Internal Medicine/Cardiology, Rush University Medical Center, Chicago, IL, 60612, USA
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8
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Fulle S, Belia S, Fanò Illic G. The Arianna thread: the matching of S-100 family with the RyR's muscle receptor. Eur J Transl Myol 2020; 30:8839. [PMID: 32499888 PMCID: PMC7254442 DOI: 10.4081/ejtm.2019.8839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 01/21/2020] [Accepted: 01/31/2020] [Indexed: 11/23/2022] Open
Abstract
The functional state of RyR depends on the intracellular calcium concentration and on the oxidation state of its protein components in some particular sites and of some sentinel amino acids. In addition to the regulation of the RyR channel by exogenous substances (caffeine, ryanodine), ions environmental situations (oxidative state), other components, such as some endogenous proteins present in the sarcoplasm and/or in muscle membranes that are able to determine changes in Ca2+ channel activity. Among these, calmodulin and S-100A could determine modifications in the status of RyR channel in the skeletal muscle. The currently available data can be justified the use of a simplified S-100/CaM and RyR interaction model for the regulation of Ca2+ release in skeletal muscle. Under resting conditions, the CaM/S100A1 binding domain on RyR1 is predominantly dependent on S100A1. Vice versa when the intracellular Ca2+ concentration becomes high as well as during repetitive (tetanus) stimulation, the Ca-CaM bond becomes dominant, shifting S100A1 from RyR1 and promoting channel inactivation. This may be one of the mechanism of muscle fatigue.
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Affiliation(s)
- Stefania Fulle
- Department of Neuroscience, Imaging and Clinical Science, University "G. d'Annunzio" Chieti-Pescara, Italy.,Interuniversity Institute of Myology (IIM)
| | - Silvia Belia
- Interuniversity Institute of Myology (IIM).,Department of Chemistry, Biology and Biotechnology, University of Perugia, Italy
| | - Giorgio Fanò Illic
- Interuniversity Institute of Myology (IIM).,Free University of Alcatraz, Santa Cristina of Gubbio, Perugia, Italy
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9
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Hu M, Lee W, Jiao J, Li X, Gibbons DE, Hassan CR, Tian GW, Qin YX. Mechanobiological modulation of in situ and in vivo osteocyte calcium oscillation by acoustic radiation force. Ann N Y Acad Sci 2019; 1460:68-76. [PMID: 31646646 DOI: 10.1111/nyas.14262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 05/31/2019] [Revised: 09/16/2019] [Accepted: 09/30/2019] [Indexed: 12/11/2022]
Abstract
The biological effect of ultrasound on bone regeneration has been well documented, yet the underlying mechanotransduction mechanism is largely unknown. In relation to the mechanobiological modulation of the cytoskeleton and Ca2+ influx by short-term focused acoustic radiation force (FARF), the current study aimed to visualize and quantify Ca2+ oscillations in real-time of in situ and in vivo osteocytes in response to focused low-intensity pulsed ultrasound (FLIPUS). For in situ studies, fresh mice calvaria were subjected to FLIPUS stimulation at 0.05, 0.2, 0.3, and 0.7 W. For the in vivo study, 3-month-old C57BL/6J Ai38/Dmp1-Cre mice were subjected to FLIPUS at 0.15, 1, and 1.5 W. As observed via real-time confocal imaging, in situ FLIPUS led to more than 80% of cells exhibiting Ca2+ oscillations at 0.3-0.7 W and led to a higher number of Ca2+ spikes with larger values at >0.3 W. In vivo FLIPUS at 1-1.5 W led to more than 90% of cells exhibiting Ca2+ oscillations. Higher FLIPUS energies led to larger Ca2+ spike magnitudes. In conclusion, this study provided a pilot study of both in situ and in vivo osteocytic Ca2+ oscillations under noninvasive FARF, which aids further exploration of the mechanosensing mechanism of the controlled bone cell motility response to the stimulus.
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Affiliation(s)
- Minyi Hu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Wonsae Lee
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Jian Jiao
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Xiaofei Li
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Daniel E Gibbons
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Chaudhry Raza Hassan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Guo-Wei Tian
- CMIC-Two Photon Imaging Center, Stony Brook University, Stony Brook, New York
| | - Yi-Xian Qin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
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10
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Watanabe D, Wada M. Effects of reduced muscle glycogen on excitation-contraction coupling in rat fast-twitch muscle: a glycogen removal study. J Muscle Res Cell Motil 2019; 40:353-64. [PMID: 31236763 DOI: 10.1007/s10974-019-09524-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 06/11/2019] [Indexed: 02/08/2023]
Abstract
The aim of this study was to investigate the effects of an enzymatic removal of glycogen on excitation-contraction coupling in mechanically skinned fibres of rat fast-twitch muscles, with a focus on the changes in the function of Na+-K+-pump and ryanodine receptor (RyR). Glycogen present in the skinned fibres and binding to microsomes was removed using glucoamylase (GA). Exposure of whole muscle to 20 U mL-1 GA for 6 min resulted in a 72% decrease in the glycogen content. Six minutes of GA treatment led to an 18 and a 22% reduction in depolarization- and action potential-induced forces in the skinned fibres, respectively. There was a minor but statistically significant increase in the repriming period, most likely because of an impairment of the Na+-K+-pump function. GA treatment exerted no effect on the maximum Ca2+ release rate from the RyR in the microsomes and the myofibrillar Ca2+ sensitivity in the skinned fibres. These results indicate that reduced glycogen per se can decrease muscle performance due to the impairment of SR Ca2+ release and suggest that although Na+-K+-pump function is adversely affected by reduced glycogen, the extent of the impairment is not sufficient to reduce Ca2+ release from the sarcoplasmic reticulum. This study provides direct evidence that glycogen above a certain amount is required for the preservation of the functional events preceding Ca2+ release from the sarcoplasmic reticulum.
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11
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O'Brien F, Eberhardt D, Witschas K, El‐Ajouz S, Iida T, Nishi M, Takeshima H, Sitsapesan R, Venturi E. Enhanced activity of multiple TRIC-B channels: an endoplasmic reticulum/sarcoplasmic reticulum mechanism to boost counterion currents. J Physiol 2019; 597:2691-2705. [PMID: 30907436 PMCID: PMC6567852 DOI: 10.1113/jp277241] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/20/2019] [Indexed: 01/27/2023] Open
Abstract
KEY POINTS There are two subtypes of trimeric intracellular cation (TRIC) channels but their distinct single-channel properties and physiological regulation have not been characterized. We examined the differences in function between native skeletal muscle sarcoplasmic reticulum (SR) K+ -channels from wild-type (WT) mice (where TRIC-A is the principal subtype) and from Tric-a knockout (KO) mice that only express TRIC-B. We find that lone SR K+ -channels from Tric-a KO mice have a lower open probability and gate more frequently in subconducting states than channels from WT mice but, unlike channels from WT mice, multiple channels gate with high open probability with a more than six-fold increase in activity when four channels are present in the bilayer. No evidence was found for a direct gating interaction between ryanodine receptor and SR K+ -channels in Tric-a KO SR, suggesting that TRIC-B-TRIC-B interactions are highly specific and may be important for meeting counterion requirements during excitation-contraction coupling in tissues where TRIC-A is sparse or absent. ABSTRACT The trimeric intracellular cation channels, TRIC-A and TRIC-B, represent two subtypes of sarcoplasmic reticulum (SR) K+ -channel but their individual functional roles are unknown. We therefore compared the biophysical properties of SR K+ -channels derived from the skeletal muscle of wild-type (WT) or Tric-a knockout (KO) mice. Because TRIC-A is the major TRIC-subtype in skeletal muscle, WT SR will predominantly contain TRIC-A channels, whereas Tric-a KO SR will only contain TRIC-B channels. When lone SR K+ -channels were incorporated into bilayers, the open probability (Po) of channels from Tric-a KO mice was markedly lower than that of channels from WT mice; gating was characterized by shorter opening bursts and more frequent brief subconductance openings. However, unlike channels from WT mice, the Po of SR K+ -channels from Tric-a KO mice increased as increasing channel numbers were present in the bilayer, driving the channels into long sojourns in the fully open state. When co-incorporated into bilayers, ryanodine receptor channels did not directly affect the gating of SR K+ -channels, nor did the presence or absence of SR K+ -channels influence ryanodine receptor activity. We suggest that because of high expression levels in striated muscle, TRIC-A produces most of the counterion flux required during excitation-contraction coupling. TRIC-B, in contrast, is sparsely expressed in most cells and, although lone TRIC-B channels exhibit low Po, the high Po levels reached by multiple TRIC-B channels may provide a compensatory mechanism to rapidly restore K+ gradients and charge differences across the SR of tissues containing few TRIC-A channels.
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Affiliation(s)
- Fiona O'Brien
- Department of PharmacologyUniversity of OxfordOxfordUK
| | | | | | - Sam El‐Ajouz
- Department of PharmacologyUniversity of OxfordOxfordUK
| | - Tsunaki Iida
- Graduate School of Pharmaceutical SciencesKyoto UniversityKyotoJapan
| | - Miyuki Nishi
- Graduate School of Pharmaceutical SciencesKyoto UniversityKyotoJapan
| | - Hiroshi Takeshima
- Graduate School of Pharmaceutical SciencesKyoto UniversityKyotoJapan
| | | | - Elisa Venturi
- Department of PharmacologyUniversity of OxfordOxfordUK
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12
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Zhang Y, Li F, Liu L, Jiang H, Hu H, Du X, Ge X, Cao J, Wang Y. Salinomycin triggers endoplasmic reticulum stress through ATP2A3 upregulation in PC-3 cells. BMC Cancer 2019; 19:381. [PMID: 31023247 PMCID: PMC6482559 DOI: 10.1186/s12885-019-5590-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 05/02/2018] [Accepted: 04/09/2019] [Indexed: 02/06/2023] Open
Abstract
Background Salinomycin is a monocarboxylic polyether antibiotic and is a potential chemotherapy drug. Our previous studies showed that salinomycin inhibited cell growth and targeted CSCs in prostate cancer. However, the precise target of salinomycin action is unclear. Methods In this work, we analyzed and identified differentially expressed genes (DEGs) after treatment with or without salinomycin using a gene expression microarray in vitro (PC-3 cells) and in vivo (NOD/SCID mice xenograft model generated from implanted PC-3 cells). Western blotting and immunohistochemical staining were used to analyze the expression of ATP2A3 and endoplasmic reticulum (ER) stress biomarkers. Flow cytometry was used to analyze the cell cycle, apoptosis and intracellular Ca2+ concentration. Results A significantly upregulated gene, ATPase sarcoplasmatic/endoplasmatic reticulum Ca2+ transporting 3 (ATP2A3), was successfully identified. In subsequent studies, we found that ATP2A3 overexpression could trigger ER stress and exert anti-cancer effects in PC-3 and DU145 cells. ATP2A3 was slightly expressed, but the ER stress biomarkers showed strong staining in prostate cancer tissues. We also found that salinomycin could trigger ER stress, which might be related to ATP2A3-mediated Ca2+ release in PC-3 cells. Furthermore, we found that salinomycin-triggered ER stress could promote apoptosis and thus exert anti-cancer effects in prostate cancer cells. Conclusion This study demonstrates that ATP2A3 might be one of the potential targets for salinomycin, which can inhibit Ca2+ release and trigger ER stress to exert anti-cancer effects.
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Affiliation(s)
- Yunsheng Zhang
- Clinical Research Institute, The Second Affiliated Hospital, University of South China; Clinical Research Center For Breast & Thyroid Disease Prevention In Hunan Province, Hengyang, 421001, People's Republic of China
| | - Fang Li
- College of Nursing, Hunan Polytechnic of Environment and Biology, Hengyang, 421005, People's Republic of China
| | - Luogen Liu
- Clinical Research Institute, The Second Affiliated Hospital, University of South China, Hengyang, 421001, People's Republic of China
| | - Hongtao Jiang
- Department of Urology, The Second Hospital, University of South China, Hengyang, 421001, People's Republic of China
| | - Hua Hu
- Cancer Research Institute, The Second Hospital, University of South China, Hengyang, 421001, People's Republic of China
| | - Xiaobo Du
- Department of Urology, The First People's Hospital Yueyang, Yueyang, 414000, People's Republic of China
| | - Xin Ge
- Clinical Research Institute, The Second Affiliated Hospital, University of South China, Hengyang, 421001, People's Republic of China
| | - Jingsong Cao
- Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, University of South China, Hengyang, 421001, People's Republic of China
| | - Yi Wang
- Department of Urology, The Second Affiliated Hospital of Hainan Medical University, Haikou 570102; Clinical Research Institute, The Second Affiliated Hospital, University of South China, Hengyang, 421001, People's Republic of China.
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13
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Shakib N, Khadem Ansari MH, Karimi P, Rasmi Y. Neuroprotective mechanism of low-dose sodium nitrite in oxygen-glucose deprivation model of cerebral ischemic stroke in PC12 cells. EXCLI J 2019; 18:229-242. [PMID: 31217786 PMCID: PMC6558507 DOI: 10.17179/excli2018-1947] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/26/2019] [Indexed: 01/29/2023]
Abstract
The purpose of this study was to clarify the mechanisms of the protective effects of low-dose sodium nitrite (SN) on oxygen and glucose deprivation (OGD)-induced endoplasmic reticulum (ER) stress in PC12 cells. The PC12 cells were exposed to 4 h of OGD and treated with 100 μmol SN. The expression and activity of ER stress markers, including PKR-like endoplasmic reticulum kinase (PERK), transcription factor 6 (ATF6), CCAAT/enhancer binding protein homologous protein (CHOP), as well as caspase-12 and -3, were detected by immunoblotting assay. Fluorescence staining was used to detect the levels of reactive oxygen species (ROS) and Ca2+ release from the ER. Cell viability was also evaluated by MTT assay. It was found that SN significantly inhibited ROS production and Ca2+ release from the ER in OGD-injured PC12 cells. Moreover, ER stress marker expression and cleaved fragments of caspase-3 and -12 in OGD-injured PC12 cells were decreased after SN treatment. These findings were accompanied by a significant increase in cell viability. It seems that SN exerts a neuroprotective effect at least partially through reduction of ROS-mediated ER stress caused by OGD insult.
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Affiliation(s)
- Nader Shakib
- Department of Biochemistry, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | | | - Pouran Karimi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yousef Rasmi
- Department of Biochemistry, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
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14
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Hernández‐Ochoa EO, Melville Z, Vanegas C, Varney KM, Wilder PT, Melzer W, Weber DJ, Schneider MF. Loss of S100A1 expression leads to Ca 2+ release potentiation in mutant mice with disrupted CaM and S100A1 binding to CaMBD2 of RyR1. Physiol Rep 2018; 6:e13822. [PMID: 30101473 PMCID: PMC6087734 DOI: 10.14814/phy2.13822] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 11/24/2022] Open
Abstract
Calmodulin (CaM) and S100A1 fine-tune skeletal muscle Ca2+ release via opposite modulation of the ryanodine receptor type 1 (RyR1). Binding to and modulation of RyR1 by CaM and S100A1 occurs predominantly at the region ranging from amino acid residue 3614-3640 of RyR1 (here referred to as CaMBD2). Using synthetic peptides, it has been shown that CaM binds to two additional regions within the RyR1, specifically residues 1975-1999 and 4295-4325 (CaMBD1 and CaMBD3, respectively). Because S100A1 typically binds to similar motifs as CaM, we hypothesized that S100A1 could also bind to CaMBD1 and CaMBD3. Our goals were: (1) to establish whether S100A1 binds to synthetic peptides containing CaMBD1 and CaMBD3 using isothermal calorimetry (ITC), and (2) to identify whether S100A1 and CaM modulate RyR1 Ca2+ release activation via sites other than CaMBD2 in RyR1 in its native cellular context. We developed the mouse model (RyR1D-S100A1KO), which expresses point mutation RyR1-L3625D (RyR1D) that disrupts the modulation of RyR1 by CaM and S100A1 at CaMBD2 and also lacks S100A1 (S100A1KO). ITC assays revealed that S100A1 binds with different affinities to CaMBD1 and CaMBD3. Using high-speed Ca2+ imaging and a model for Ca2+ binding and transport, we show that the RyR1D-S100A1KO muscle fibers exhibit a modest but significant increase in myoplasmic Ca2+ transients and enhanced Ca2+ release flux following field stimulation when compared to fibers from RyR1D mice, which were used as controls to eliminate any effect of binding at CaMBD2, but with preserved S100A1 expression. Our results suggest that S100A1, similar to CaM, binds to CaMBD1 and CaMBD3 within the RyR1, but that CaMBD2 appears to be the primary site of RyR1 regulation by CaM and S100A1.
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Affiliation(s)
- Erick O. Hernández‐Ochoa
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
| | - Zephan Melville
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
| | - Camilo Vanegas
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
| | - Kristen M. Varney
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
- Center for Biomolecular Therapeutics (CBT)University of Maryland School of MedicineMaryland
| | - Paul T. Wilder
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
- Center for Biomolecular Therapeutics (CBT)University of Maryland School of MedicineMaryland
| | - Werner Melzer
- Institute of Applied PhysiologyUlm UniversityUlmGermany
| | - David J. Weber
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
- Center for Biomolecular Therapeutics (CBT)University of Maryland School of MedicineMaryland
| | - Martin F. Schneider
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMaryland
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15
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Hernández-Ochoa EO, Schneider MF. Voltage sensing mechanism in skeletal muscle excitation-contraction coupling: coming of age or midlife crisis? Skelet Muscle 2018; 8:22. [PMID: 30025545 PMCID: PMC6053751 DOI: 10.1186/s13395-018-0167-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/26/2018] [Indexed: 11/10/2022] Open
Abstract
The process by which muscle fiber electrical depolarization is linked to activation of muscle contraction is known as excitation-contraction coupling (ECC). Our understanding of ECC has increased enormously since the early scientific descriptions of the phenomenon of electrical activation of muscle contraction by Galvani that date back to the end of the eighteenth century. Major advances in electrical and optical measurements, including muscle fiber voltage clamp to reveal membrane electrical properties, in conjunction with the development of electron microscopy to unveil structural details provided an elegant view of ECC in skeletal muscle during the last century. This surge of knowledge on structural and biophysical aspects of the skeletal muscle was followed by breakthroughs in biochemistry and molecular biology, which allowed for the isolation, purification, and DNA sequencing of the muscle fiber membrane calcium channel/transverse tubule (TT) membrane voltage sensor (Cav1.1) for ECC and of the muscle ryanodine receptor/sarcoplasmic reticulum Ca2+ release channel (RyR1), two essential players of ECC in skeletal muscle. In regard to the process of voltage sensing for controlling calcium release, numerous studies support the concept that the TT Cav1.1 channel is the voltage sensor for ECC, as well as also being a Ca2+ channel in the TT membrane. In this review, we present early and recent findings that support and define the role of Cav1.1 as a voltage sensor for ECC.
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Affiliation(s)
- Erick O. Hernández-Ochoa
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201 USA
| | - Martin F. Schneider
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201 USA
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16
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Leong IL, Tsai TY, Wong KL, Shiao LR, Cheng KS, Chan P, Leung YM. Valproic acid inhibits ATP-triggered Ca 2+ release via a p38-dependent mechanism in bEND.3 endothelial cells. Fundam Clin Pharmacol 2018; 32:499-506. [PMID: 29752814 DOI: 10.1111/fcp.12381] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 04/22/2018] [Accepted: 05/04/2018] [Indexed: 01/06/2023]
Abstract
Valproic acid (VA) is currently used to treat epilepsy and bipolar disorder. It has also been demonstrated to promote neuroprotection and neurogenesis. Although beneficial actions of VA on brain blood vessels have also been demonstrated, the effects of VA on brain endothelial cell (EC) Ca2+ signaling are hitherto unreported. In this report, we examined the effects of VA on agonist-triggered Ca2+ signaling in mouse cortical bEND.3 EC. While VA (100 μm) did not cause an acute inhibition of ATP-triggered Ca2+ signaling, a 30-min VA treatment strongly suppressed ATP-triggered intracellular Ca2+ release; however, such treatment did not affect Ca2+ release triggered by cyclopiazonic acid, an inhibitor of SERCA Ca2+ pump, suggesting there was no reduction in Ca2+ store size. VA-activated p38 signaling, and VA-induced inhibition of ATP-triggered Ca2+ release was prevented by SB203580, a p38 inhibitor, suggesting VA caused the inhibition by activating p38. Remarkably, VA treatment did not affect acetylcholine-triggered Ca2+ release, suggesting VA may not inhibit inositol 1,4,5-trisphosphate-induced Ca2+ release per se, and may not act directly on Gq or phospholipase C. Taken together, our results suggest VA treatment, via a p38-dependent mechanism, led to an inhibition of purinergic receptor-effector coupling.
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Affiliation(s)
- Iat-Lon Leong
- Division of Cardiology, Department of Internal Medicine, Kiang Wu Hospital, 33 Estrada do Repouso, Macau, China
| | - Tien-Yao Tsai
- School of Medicine, College of Medicine, Fu Jen Catholic University, 510 Zhongzheng Road, New Taipei City, Taiwan.,Cardiovascular Division, Fu Jen Catholic University Hospital, 69 Guizi Road, New Taipei City, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, 2 Yude Road, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, 91 Hsuehshi Road, Taichung, Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University Hospital, 2 Yude Road, Taichung, Taiwan.,Department of Anesthesiology, The Qingdao University Yuhuangding Hospital, 20 Yuhuangding East Road, Yantai, Shandong, China
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, 111 Xinglong Road, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, 91 Hsuehshi Road, Taichung, Taiwan
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17
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Li T, Wang L, Ma T, Wang S, Niu J, Li H, Xiao L. Dynamic Calcium Release From Endoplasmic Reticulum Mediated by Ryanodine Receptor 3 Is Crucial for Oligodendroglial Differentiation. Front Mol Neurosci 2018; 11:162. [PMID: 29867353 PMCID: PMC5968115 DOI: 10.3389/fnmol.2018.00162] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [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: 11/30/2017] [Accepted: 04/30/2018] [Indexed: 12/15/2022] Open
Abstract
Increased intracellular Ca2+ in oligodendrocyte progenitor cells (OPCs) is important to initiate their differentiation, but the intracellular Ca2+ channel involved in this process remains unclear. As a Ca2+-induced Ca2+ release (CICR) channel that mediates endoplasmic reticulum (ER) Ca2+ release, the role of ryanodine receptors (RyRs) in oligodendroglial development is unexplored. In the present study, we observed that among the three mammalian isoforms, oligodendroglial lineage cells selectively expressed RyR3. Strong RyR3-positive signal was distributed all over the cytoplasm and processes in OPCs and/or immature OLs (imOLs), whereas it gradually decreased and was located mainly around the perinuclear region in mature oligodendrocytes (OLs). In addition, RyR3-mediated intracellular Ca2+ waves following caffeine stimulation were correlated with the expression pattern of RyR3, in which high flat Ca2+ fluctuations and oscillatory Ca2+ waves were more frequently recorded in OPCs and/or imOLs than in OLs. Through further functional exploration, we demonstrated that pretreatment with the RyR antagonist ryanodine could neutralize the increase in intracellular Ca2+ induced by OPC differentiation and reduce the number of mature OLs. Moreover, gene-level knockdown of RyR3 by lentivirus in OPCs resulted in inhibition of OPC differentiation. Taken together, our results provide new insight into the crucial role of RyR3-mediated ER Ca2+ release in the regulation of OPC differentiation and/or myelination.
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Affiliation(s)
- Tao Li
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Lingyun Wang
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Teng Ma
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Shouyu Wang
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Jianqin Niu
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Hongli Li
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
| | - Lan Xiao
- Chongqing Key Laboratory of Neurobiology, Department of Histology and Embryology, Third Military Medical University, Chongqing, China
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18
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Hong J, Fristiohady A, Nguyen CH, Milovanovic D, Huttary N, Krieger S, Hong J, Geleff S, Birner P, Jäger W, Özmen A, Krenn L, Krupitza G. Apigenin and Luteolin Attenuate the Breaching of MDA-MB231 Breast Cancer Spheroids Through the Lymph Endothelial Barrier in Vitro. Front Pharmacol 2018; 9:220. [PMID: 29593542 PMCID: PMC5861143 DOI: 10.3389/fphar.2018.00220] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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: 10/05/2017] [Accepted: 02/27/2018] [Indexed: 11/13/2022] Open
Abstract
Flavonoids, present in fruits, vegetables and traditional medicinal plants, show anticancer effects in experimental systems and are reportedly non-toxic. This is a favorable property for long term strategies for the attenuation of lymph node metastasis, which may effectively improve the prognostic states in breast cancer. Hence, we studied two flavonoids, apigenin and luteolin exhibiting strong bio-activity in various test systems in cancer research and are readily available on the market. This study has further advanced the mechanistic understanding of breast cancer intravasation through the lymphatic barrier. Apigenin and luteolin were tested in a three-dimensional (3-D) assay consisting of MDA-MB231 breast cancer spheroids and immortalized lymph endothelial cell (LEC) monolayers. The 3-D model faithfully resembles the intravasation of breast cancer emboli through the lymphatic vasculature. Western blot analysis, intracellular Ca2+ determination, EROD assay and siRNA transfection revealed insights into mechanisms of intravasation as well as the anti-intravasative outcome of flavonoid action. Both flavonoids suppressed pro-intravasative trigger factors in MDA-MB231 breast cancer cells, specifically MMP1 expression and CYP1A1 activity. A pro-intravasative contribution of FAK expression in LECs was established as FAK supported the retraction of the LEC monolayer upon contact with cancer cells thereby enabling them to cross the endothelial barrier. As mechanistic basis, MMP1 caused the phosphorylation (activation) of FAK at Tyr397 in LECs. Apigenin and luteolin prevented MMP1-induced FAK activation, but not constitutive FAK phosphorylation. Luteolin, unlike apigenin, inhibited MMP1-induced Ca2+ release. Free intracellular Ca2+ is a central signal amplifier triggering LEC retraction through activation of the mobility protein MLC2, thereby enhancing intravasation. FAK activity and Ca2+ levels did not correlate. This implicates that the pro-intravasative contribution of FAK and of Ca2+ release in LECs was independent of each other and explains the better anti-intravasative effects of luteolin in vitro. In specific formulations, flavonoid concentrations causing significant anti-intravasative effects, can certainly be achieved in vivo. As the therapeutic strategy has to be based on permanent flavonoid treatment both the beneficial and adverse effects have to be investigated in future studies.
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Affiliation(s)
- Junli Hong
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Vienna, Austria.,School of Pharmacy, Nanjing Medical University, Nanjing, China.,Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Adryan Fristiohady
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria.,Department for Clinical Pharmacy and Diagnostics, Faculty of Life Sciences, University of Vienna, Vienna, Austria.,Faculty of Pharmacy, Halu Oleo University, Kendari, Indonesia
| | - Chi H Nguyen
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria.,Department for Clinical Pharmacy and Diagnostics, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Daniela Milovanovic
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Nicole Huttary
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Sigurd Krieger
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Junqiang Hong
- Department of Medical Oncology, The 188th Hospital of People's Liberation Army of China, Chaozhou, China
| | - Silvana Geleff
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Peter Birner
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Walter Jäger
- Department for Clinical Pharmacy and Diagnostics, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Ali Özmen
- Department of Biology, Faculty of Science and Art, Adnan Menderes University, Aydin, Turkey
| | - Liselotte Krenn
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Georg Krupitza
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
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19
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Liao C, Zheng K, Li Y, Xu H, Kang Q, Fan L, Hu X, Jin Z, Zeng Y, Kong X, Zhang J, Wu X, Wu H, Liu L, Xiao X, Wang Y, He Z. Gypenoside L inhibits autophagic flux and induces cell death in human esophageal cancer cells through endoplasm reticulum stress-mediated Ca2+ release. Oncotarget 2018; 7:47387-47402. [PMID: 27329722 PMCID: PMC5216949 DOI: 10.18632/oncotarget.10159] [Citation(s) in RCA: 20] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 06/06/2016] [Indexed: 12/17/2022] Open
Abstract
Esophageal cancer is one of the leading cause of cancer mortality in the world. Due to the increased drug and radiation tolerance, it is urgent to develop novel anticancer agent that triggers nonapoptotic cell death to compensate for apoptosis resistance. In this study, we show that treatment with gypenoside L (Gyp-L), a saponin isolated from Gynostemma pentaphyllum, induced nonapoptotic, lysosome-associated cell death in human esophageal cancer cells. Gyp-L-induced cell death was associated with lysosomal swelling and autophagic flux inhibition. Mechanistic investigations revealed that through increasing the levels of intracellular reactive oxygen species (ROS), Gyp-L triggered protein ubiquitination and endoplasm reticulum (ER) stress response, leading to Ca2+ release from ER inositol trisphosphate receptor (IP3R)-operated stores and finally cell death. Interestingly, there existed a reciprocal positive-regulatory loop between Ca2+ release and ER stress in response to Gyp-L. In addition, protein synthesis was critical for Gyp-L-mediated ER stress and cell death. Taken together, this work suggested a novel therapeutic option by Gyp-L through the induction of an unconventional ROS-ER-Ca2+-mediated cell death in human esophageal cancer.
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Affiliation(s)
- Chenghui Liao
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Kai Zheng
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China.,College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Yan Li
- The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Hong Xu
- College of Life Sciences, Shenzhen University, Shenzhen, China
| | - Qiangrong Kang
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Long Fan
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Xiaopeng Hu
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Zhe Jin
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Yong Zeng
- The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiaoli Kong
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Jian Zhang
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Xuli Wu
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Haiqiang Wu
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Lizhong Liu
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
| | - Xiaohua Xiao
- The First Affiliated Hospital of School of Medicine, Shenzhen University, Shenzhen, China
| | - Yifei Wang
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Zhendan He
- Department of Pharmacy, School of Medicine, Shenzhen Key Laboratory of Novel Natural Health Care Products, Innovation Platform for Natural Small Molecule Drugs, Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University, Shenzhen, China
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20
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Wu KC, Wong KL, Wang ML, Shiao LR, Leong IL, Gong CL, Cheng KS, Chan P, Leung YM. Eicosapentaenoic acid triggers Ca 2+ release and Ca 2+ influx in mouse cerebral cortex endothelial bEND.3 cells. J Physiol Sci 2018; 68:33-41. [PMID: 27873157 PMCID: PMC10717322 DOI: 10.1007/s12576-016-0503-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 11/11/2016] [Indexed: 11/29/2022]
Abstract
Eicosapentaenoic acid (EPA), an omega-3 fatty acid abundant in fish oil, protects endothelial cells (EC) from lipotoxicity and triggers EC NO release. The latter is related to an elevation of cytosolic Ca2+. Although EPA has been shown to cause human EC cytosolic Ca2+ elevation, the mechanism is unclear. Microfluorimetric imaging was used here to measure free cytosolic Ca2+ concentration. EPA was shown to cause intracellular Ca2+ release in mouse cerebral cortex endothelial bEND.3 cells; interestingly, the EPA-sensitive intracellular Ca2+ pool(s) appeared to encompass and was larger than the Ca2+ pool mobilized by sarcoplasmic-endoplasmic reticulum Ca2+-ATPase inhibition by cyclopiazonic acid. EPA also opened a Ca2+ influx pathway pharmacologically distinct from store-operated Ca2+ influx. Surprisingly, EPA-triggered Ca2+ influx was Ni2+-insensitive; and EPA did not trigger Mn2+ influx. Further, EPA-triggered Ca2+ influx did not involve Na+-Ca2+ exchangers. Thus, our results suggest EPA triggered unusual mechanisms of Ca2+ release and Ca2+ influx in EC.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi, Taiwan
- Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
| | - Mei-Ling Wang
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Iat-Lon Leong
- Division of Cardiology, Department of Internal Medicine, Kiang Wu Hospital, Macau, China
| | - Chi-Li Gong
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
- Department of Anesthesiology, The Qingdao University Yuhuangding Hospital, Yantai, Shandong, China
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan.
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Singh JK, Barsegyan V, Bassi N, Marszalec W, Tai S, Mothkur S, Mulla M, Nico E, Shiferaw Y, Aistrup GL, Wasserstrom JA. T-tubule remodeling and increased heterogeneity of calcium release during the progression to heart failure in intact rat ventricle. Physiol Rep 2017; 5:5/24/e13540. [PMID: 29279414 PMCID: PMC5742703 DOI: 10.14814/phy2.13540] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 05/09/2017] [Revised: 11/07/2017] [Accepted: 11/10/2017] [Indexed: 01/29/2023] Open
Abstract
A highly organized transverse‐tubule (TT) system is essential to normal Ca2+ cycling and cardiac function. We explored the relationship between the progressive disruption of TTs and resulting Ca2+ cycling during the development of heart failure (HF). Confocal imaging was used to measure Ca2+ transients and 2‐D z‐stack images in left ventricular epicardial myocytes of intact hearts from spontaneously hypertensive rats (SHR) and Wistar‐Kyoto control rats. TT organization was measured as the organizational index (OI) derived from a fast Fourier transform of TT organization. We found little decrease in the synchrony of Ca2+ release with TT loss until TT remodeling was severe, suggesting a TT “reserve” characterized by a wide range of TT remodeling with little effect on synchrony of release but beyond which variability in release shows an accelerating sensitivity to TT loss. To explain this observation, we applied a computational model of spatially distributed Ca2+ signaling units to investigate the relationship between OI and excitation‐contraction coupling. Our model showed that release heterogeneity exhibits a nonlinear relationship on both the spatial distribution of release units and the separation between L‐type Ca2+ channels and ryanodine receptors. Our results demonstrate a unique relationship between the synchrony of Ca2+ release and TT organization in myocytes of intact rat ventricle that may contribute to both the compensated and decompensated phases of heart failure.
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Affiliation(s)
- Jasleen K Singh
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Varderes Barsegyan
- Department of Physics and Astronomy, California State University, Northridge, California
| | - Nikhil Bassi
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - William Marszalec
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Shannon Tai
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Shruthi Mothkur
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Maaz Mulla
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Elsa Nico
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Yohannes Shiferaw
- Department of Physics and Astronomy, California State University, Northridge, California
| | - Gary L Aistrup
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - John Andrew Wasserstrom
- Department of Medicine (Cardiology), The Feinberg Cardiovascular Research Institute Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Zhang J, Liu H, Sun Z, Xie J, Zhong G, Yi X. Azadirachtin induced apoptosis in the prothoracic gland in Bombyx mori and a pronounced Ca 2+ release effect in Sf9 cells. Int J Biol Sci 2017; 13:1532-1539. [PMID: 29230101 PMCID: PMC5723919 DOI: 10.7150/ijbs.22175] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 07/31/2017] [Accepted: 10/15/2017] [Indexed: 11/05/2022] Open
Abstract
Azadirachtin is a bio-rational insecticide used as an antifeedant and growth disruption agent against many insect species. However, recent studies have shown that there is a potential risk of this compound harming some beneficial insects. In such cases its application does not normally lead to death, but it may result in altered developmental regulation. Therefore, it is essential to obtain toxicological data to understand the mechanism of such sub-lethal effects, especially where they relate to important beneficial insects. Here, we found that azadirachtin could regulate growth and cocooning in silkworms, which may be associated with induced apoptotic effect on the prothoracic gland. However, azadirachtin treatment could not induce apoptosis in the prothoracic gland in vitro, in contrast to the effect of 20-hydroxyecdysone in vitro, which suggesting that the apoptosis might not be direct effect of azadirachtin. Then we examined the activity of Ca2+-Mg2+-ATPase and found that azadirachtin could trigger a significant increase in intracellular Ca2+ release in the Sf9 cell line, which suggested that the calcium signaling pathway might be involved in the process of apoptosis in prothoracic gland and growth regulation in vivo silkworms. Although more evidence is needed to fully understand the mechanism of azadirachtin in perturbing the growth of silkworms, this study provides some toxicological information and highlights the potential risks of azadirachtin in relation to silkworms.
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Affiliation(s)
- Jing Zhang
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Hongmei Liu
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Zhipeng Sun
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Jianjun Xie
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Guohua Zhong
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Xin Yi
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
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Perez CF, Eltit JM, Lopez JR, Bodnár D, Dulhunty AF, Aditya S, Casarotto MG. Functional and structural characterization of a novel malignant hyperthermia-susceptible variant of DHPR-β 1a subunit (CACNB1). Am J Physiol Cell Physiol 2017; 314:C323-C333. [PMID: 29212769 DOI: 10.1152/ajpcell.00187.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Malignant hyperthermia (MH) susceptibility has been recently linked to a novel variant of β1a subunit of the dihydropyridine receptor (DHPR), a channel essential for Ca2+ regulation in skeletal muscle. Here we evaluate the effect of the mutant variant V156A on the structure/function of DHPR β1a subunit and assess its role on Ca2+ metabolism of cultured myotubes. Using differential scanning fluorimetry, we show that mutation V156A causes a significant reduction in thermal stability of the Src homology 3/guanylate kinase core domain of β1a subunit. Expression of the variant subunit in β1-null mouse myotubes resulted in increased sensitivity to caffeine stimulation. Whole cell patch-clamp analysis of β1a-V156A-expressing myotubes revealed a -2 mV shift in voltage dependence of channel activation, but no changes in Ca2+ conductance, current kinetics, or sarcoplasmic reticulum Ca2+ load were observed. Measurement of resting free Ca2+ and Na+ concentrations shows that both cations were significantly elevated in β1a-V156A-expressing myotubes and that these changes were linked to increased rates of plasmalemmal Ca2+ entry through Na+/Ca2+ exchanger and/or transient receptor potential canonical channels. Overall, our data show that mutant variant V156A results in instability of protein subdomains of β1a subunit leading to a phenotype of Ca2+ dysregulation that partly resembles that of other MH-linked mutations of DHPR α1S subunit. These data prove that homozygous expression of variant β1a-V156A has the potential to be a pathological variant, although it may require other gene defects to cause a full MH phenotype.
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Affiliation(s)
- Claudio F Perez
- Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Jose M Eltit
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University , Richmond, Virginia
| | - Jose R Lopez
- Department of Molecular Biosciences, University of California , Davis, California
| | - Dóra Bodnár
- Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Angela F Dulhunty
- John Curtin School of Medical Research, Australian National University , Canberra , Australia
| | - Shouvik Aditya
- John Curtin School of Medical Research, Australian National University , Canberra , Australia
| | - Marco G Casarotto
- John Curtin School of Medical Research, Australian National University , Canberra , Australia
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Shen Z, Zhang Z, Wang X, Yang K. VEGFB-VEGFR1 ameliorates Ang II-induced cardiomyocyte hypertrophy through Ca 2+ -mediated PKG I pathway. J Cell Biochem 2017; 119:1511-1520. [PMID: 28771828 DOI: 10.1002/jcb.26311] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 06/27/2017] [Accepted: 08/02/2017] [Indexed: 01/18/2023]
Abstract
In response to assorted stimuli, the heart will develop into cardiomyocyte hypertrophy, but sustained cardiomyocyte hypertrophy will finally lead to heart failure. This research is aimed to examine the effect of VEGFB on cardiomyocyte hypertrophy by using the cardiomyocyte-derived cell line H9C2 of cultured rates. It turns out that VEGFB can positively prevent the Ang II-induced rising in the size of cardiomyocyte as well as reduce Ang II-induced mRNA and protein levels of β-MHC (β-myosin heavy chain), BNP (brain natriuretic peptide), and ANP (atrial natriuretic peptide). Moreover, VEGFB can regulate the decline of the Ang II-induced rising in Ca2+ . After VEGFR1 knockdown, these effects of VEGFB were partially reversed. Moreover, VEGFB attenuated the suppression of PKG I, p-VASP, and RGS2 caused by Ang II; whereas VEGFR1 knockdown partially abolished the indicated effect of VEGFB. In a word, the effect of VEGFB on relevant downstream targets and the pathways of PKG I by VEGFR1 may explain its efficacy on cardiomyocyte hypertrophy. Thus, it can be suggested that it is feasible to apply VEGFB-VEGFR1 for reducing the symptoms of cardiomyocyte hypertrophy.
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Affiliation(s)
- Zhijie Shen
- Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhihui Zhang
- Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaoyan Wang
- Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Kan Yang
- Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
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El-Ajouz S, Venturi E, Witschas K, Beech M, Wilson AD, Lindsay C, Eberhardt D, O'Brien F, Iida T, Nishi M, Takeshima H, Sitsapesan R. Dampened activity of ryanodine receptor channels in mutant skeletal muscle lacking TRIC-A. J Physiol 2017; 595:4769-4784. [PMID: 28387457 PMCID: PMC5509884 DOI: 10.1113/jp273550] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/29/2017] [Indexed: 01/02/2023] Open
Abstract
KEY POINTS The role of trimeric intracellular cation (TRIC) channels is not known, although evidence suggests they may regulate ryanodine receptors (RyR) via multiple mechanisms. We therefore investigated whether Tric-a gene knockout (KO) alters the single-channel function of skeletal RyR (RyR1). We find that RyR1 from Tric-a KO mice are more sensitive to inhibition by divalent cations, although they respond normally to cytosolic Ca2+ , ATP, caffeine and luminal Ca2+ . In the presence of Mg2+ , ATP cannot effectively activate RyR1 from Tric-a KO mice. Additionally, RyR1 from Tric-a KO mice are not activated by protein kinase A phosphorylation, demonstrating a defect in the ability of β-adrenergic stimulation to regulate sarcoplasmic reticulum (SR) Ca2+ -release. The defective RyR1 gating that we describe probably contributes significantly to the impaired SR Ca2+ -release observed in skeletal muscle from Tric-a KO mice, further highlighting the importance of TRIC-A for normal physiological regulation of SR Ca2+ -release in skeletal muscle. ABSTRACT The type A trimeric intracellular cation channel (TRIC-A) is a major component of the nuclear and sarcoplasmic reticulum (SR) membranes of cardiac and skeletal muscle, and is localized closely with ryanodine receptor (RyR) channels in the SR terminal cisternae. The skeletal muscle of Tric-a knockout (KO) mice is characterized by Ca2+ overloaded and swollen SR and by changes in the properties of SR Ca2+ release. We therefore investigated whether 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. We find that RyR1 channels from Tric-a KO mice respond normally to cytosolic Ca2+ , ATP, adenine, caffeine and to luminal Ca2+ . However, the channels are more sensitive to the inactivating effects of divalent cations, thus, in the presence of Mg2+ , ATP is inadequate as an activator. Additionally, channels are not characteristically activated by protein kinase A even though the phosphorylation levels of Ser2844 are similar to controls. The results of the present study suggest that TRIC-A functions as an excitatory modulator of RyR1 channels within the SR terminal cisternae. Importantly, this regulatory action of TRIC-A appears to be independent of (although additive to) any indirect consequences to RyR1 activity that arise as a result of K+ fluxes across the SR via TRIC-A.
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Affiliation(s)
- Sam El-Ajouz
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Elisa Venturi
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Katja Witschas
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Matthew Beech
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Chris Lindsay
- Department of Pharmacology, University of Oxford, Oxford, UK.,Department of Chemistry, University of Oxford, Oxford, UK
| | - David Eberhardt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Fiona O'Brien
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Tsunaki Iida
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Miyuki Nishi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Hiroshi Takeshima
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
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Abstract
Mitochondria extensively modify virtually all cellular Ca2+ transport processes, and store-operated Ca2+ entry (SOCE) is no exception to this rule. The interaction between SOCE and mitochondria is complex and reciprocal, substantially altering and, ultimately, fine-tuning both capacitative Ca2+ influx and mitochondrial function. Mitochondria, owing to their considerable Ca2+ accumulation ability, extensively buffer the cytosolic Ca2+ in their vicinity. In turn, the accumulated ion is released back into the neighboring cytosol during net Ca2+ efflux. Since store depletion itself and the successive SOCE are both Ca2+-regulated phenomena, mitochondrial Ca2+ handling may have wide-ranging effects on capacitative Ca2+ influx at any given time. In addition, mitochondria may also produce or consume soluble factors known to affect store-operated channels. On the other hand, Ca2+ entering the cell during SOCE is sensed by mitochondria, and the ensuing mitochondrial Ca2+ uptake boosts mitochondrial energy metabolism and, if Ca2+ overload occurs, may even lead to apoptosis or cell death. In several cell types, mitochondria seem to be sterically excluded from the confined space that forms between the plasma membrane (PM) and endoplasmic reticulum (ER) during SOCE. This implies that high-Ca2+ microdomains comparable to those observed between the ER and mitochondria do not form here. In the following chapter, the above aspects of the many-sided SOCE-mitochondrion interplay will be discussed in greater detail.
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Affiliation(s)
- András Spät
- Department of Physiology, Semmelweis University Medical School, POB 2, 1428, Budapest, Hungary.
- Laboratory of Molecular Physiology, Hungarian Academy of Sciences, Budapest, Hungary.
| | - Gergö Szanda
- Department of Physiology, Semmelweis University Medical School, POB 2, 1428, Budapest, Hungary
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27
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Zhang JZ, Waddell HM, Wu E, Dholakia J, Okolo CA, McLay JC, Jones PP. FKBPs facilitate the termination of spontaneous Ca2+ release in wild-type RyR2 but not CPVT mutant RyR2. Biochem J 2016; 473:2049-60. [PMID: 27154203 DOI: 10.1042/BCJ20160389] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/06/2016] [Indexed: 01/08/2023]
Abstract
FK506-binding proteins 12.6 (FKBP12.6) and 12 (FKBP12) tightly associate with the cardiac ryanodine receptor (RyR2). Studies suggest that dissociation of FKBP12.6 from mutant forms of RyR2 contributes to store overload-induced Ca(2+) release (SOICR) and Ca(2+)-triggered arrhythmias. However, these findings are controversial. Previous studies focused on the effect of FKBP12.6 on the initiation of SOICR and did not explore changes in the termination of Ca(2+) release. Less is known about FKBP12. We aimed to determine the effect of FKBP12.6 and FKBP12 on the termination of SOICR. Using single-cell imaging, in cells expressing wild-type RyR2, we found that FKBP12.6 and FKBP12 significantly increase the termination threshold of SOICR without changing the activation threshold of SOICR. This effect, dependent on the association of each FKBP with RyR2, reduced the magnitude of Ca(2+) release but had no effect on the propensity for SOICR. In contrast, neither FKBP12.6 nor FKBP12 was able to regulate an arrhythmogenic variant of RyR2, despite a conserved protein interaction. Our results suggest that both FKBP12.6 and FKBP12 play critical roles in regulating RyR2 function by facilitating the termination of SOICR. The inability of FKBPs to mediate a similar effect on the mutant RyR2 represents a novel mechanism by which mutations within RyR2 lead to arrhythmia.
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Xiao B, Kuang Z, Zhan Y, Chen D, Gao Y, Li M, Luo S, Hao W. A Novel Polyclonal Antiserum against Toxoplasma gondii Sodium Hydrogen Exchanger 1. Korean J Parasitol 2016; 54:21-9. [PMID: 26951975 PMCID: PMC4792324 DOI: 10.3347/kjp.2016.54.1.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022]
Abstract
The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
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Affiliation(s)
- Bin Xiao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Zhenzhan Kuang
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yanli Zhan
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Daxiang Chen
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yang Gao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Ming Li
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Shuhong Luo
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Wenbo Hao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
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DiFranco M, Kramerova I, Vergara JL, Spencer MJ. Attenuated Ca(2+) release in a mouse model of limb girdle muscular dystrophy 2A. Skelet Muscle 2016; 6:11. [PMID: 26913171 PMCID: PMC4765215 DOI: 10.1186/s13395-016-0081-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [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: 11/23/2015] [Accepted: 01/30/2016] [Indexed: 02/02/2023] Open
Abstract
Background Mutations in CAPN3 cause limb girdle muscular dystrophy type 2A (LGMD2A), a progressive muscle wasting disease. CAPN3 is a non-lysosomal, Ca-dependent, muscle-specific proteinase. Ablation of CAPN3 (calpain-3 knockout (C3KO) mice) leads to reduced ryanodine receptor (RyR1) expression and abnormal Ca2+/calmodulin-dependent protein kinase II (Ca-CaMKII)-mediated signaling. We previously reported that Ca2+ release measured by fura2-FF imaging in response to single action potential stimulation was reduced in old C3KO mice; however, the use of field stimulation prevented investigation of the mechanisms underlying this impairment. Furthermore, our prior studies were conducted on older animals, whose muscles showed advanced muscular dystrophy, which prevented us from establishing whether impaired Ca2+ handling is an early feature of disease. In the current study, we sought to overcome these matters by studying single fibers isolated from young wild-type (WT) and C3KO mice using a low affinity calcium dye and high intracellular ethylene glycol-bis(2-aminoethylether)-n,n,n′,n′-tetraacetic acid (EGTA) to measure Ca2+ fluxes. Muscles were subjected to both current and voltage clamp conditions. Methods Standard and confocal fluorescence microscopy was used to study Ca2+ release in single fibers enzymatically isolated from hind limb muscles of wild-type and C3KO mice. Two microelectrode amplifier and experiments were performed under current or voltage clamp conditions. Calcium concentration changes were detected with an impermeant low affinity dye in the presence of high EGTA intracellular concentrations, and fluxes were calculated with a single compartment model. Standard Western blotting analysis was used to measure the concentration of RyR1 and the α subunit of the dihydropyridine (αDHPR) receptors. Data are presented as mean ± SEM and compared with the Student’s test with significance set at p < 0.05. Results We found that the peak value of Ca2+ fluxes elicited by single action potentials was significantly reduced by 15–20 % in C3KO fibers, but the kinetics was unaltered. Ca2+ release elicited by tetanic stimulation was also impaired in C3KO fibers. Confocal studies confirmed that Ca2+ release was similarly reduced in all triads of C3KO mice. Voltage clamp experiments revealed a normal voltage dependence of Ca2+ release in C3KO mice but reduced peak Ca2+ fluxes as with action potential stimulation. These findings concur with biochemical observations of reduced RyR1 and αDHPR levels in C3KO muscles and reduced mechanical output. Confocal studies revealed a similar decrease in Ca2+ release at all triads consistent with a homogenous reduction of functional voltage activated Ca2+ release sites. Conclusions Overall, these results suggest that decreased Ca2+ release is an early defect in calpainopathy and may contribute to the observed reduction of CaMKII activation in C3KO mice.
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Affiliation(s)
- Marino DiFranco
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095 USA ; Center for Duchenne Muscular Dystrophy at UCLA, 635 Charles E. Young Dr. South, NRB Rm. 401, Los Angeles, CA 90095 USA
| | - Irina Kramerova
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 90095 USA ; Center for Duchenne Muscular Dystrophy at UCLA, 635 Charles E. Young Dr. South, NRB Rm. 401, Los Angeles, CA 90095 USA
| | - Julio L Vergara
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095 USA ; Center for Duchenne Muscular Dystrophy at UCLA, 635 Charles E. Young Dr. South, NRB Rm. 401, Los Angeles, CA 90095 USA
| | - Melissa Jan Spencer
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 90095 USA ; Center for Duchenne Muscular Dystrophy at UCLA, 635 Charles E. Young Dr. South, NRB Rm. 401, Los Angeles, CA 90095 USA
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Kohn E, Katz B, Yasin B, Peters M, Rhodes E, Zaguri R, Weiss S, Minke B. Functional cooperation between the IP3 receptor and phospholipase C secures the high sensitivity to light of Drosophila photoreceptors in vivo. J Neurosci 2015; 35:2530-46. [PMID: 25673847 DOI: 10.1523/JNEUROSCI.3933-14.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Drosophila phototransduction is a model system for the ubiquitous phosphoinositide signaling. In complete darkness, spontaneous unitary current events (dark bumps) are produced by spontaneous single Gqα activation, while single-photon responses (quantum bumps) arise from synchronous activation of several Gqα molecules. We have recently shown that most of the spontaneous single Gqα activations do not produce dark bumps, because of a critical phospholipase Cβ (PLCβ) activity level required for bump generation. Surpassing the threshold of channel activation depends on both PLCβ activity and cellular [Ca(2+)], which participates in light excitation via a still unclear mechanism. We show here that in IP3 receptor (IP3R)-deficient photoreceptors, both light-activated Ca(2+) release from internal stores and light sensitivity were strongly attenuated. This was further verified by Ca(2+) store depletion, linking Ca(2+) release to light excitation. In IP3R-deficient photoreceptors, dark bumps were virtually absent and the quantum-bump rate was reduced, indicating that Ca(2+) release from internal stores is necessary to reach the critical level of PLCβ catalytic activity and the cellular [Ca(2+)] required for excitation. Combination of IP3R knockdown with reduced PLCβ catalytic activity resulted in highly suppressed light responses that were partially rescued by cellular Ca(2+) elevation, showing a functional cooperation between IP3R and PLCβ via released Ca(2+). These findings suggest that in contrast to the current dogma that Ca(2+) release via IP3R does not participate in light excitation, we show that released Ca(2+) plays a critical role in light excitation. The positive feedback between PLCβ and IP3R found here may represent a common feature of the inositol-lipid signaling.
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Liu DD, Ren Z, Yang G, Zhao QR, Mei YA. Melatonin protects rat cerebellar granule cells against electromagnetic field-induced increases in Na(+) currents through intracellular Ca(2+) release. J Cell Mol Med 2014; 18:1060-70. [PMID: 24548607 PMCID: PMC4508145 DOI: 10.1111/jcmm.12250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [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: 08/27/2013] [Accepted: 01/18/2014] [Indexed: 01/12/2023] Open
Abstract
Although melatonin (MT) has been reported to protect cells against oxidative damage induced by electromagnetic radiation, few reports have addressed whether there are other protective mechanisms. Here, we investigated the effects of MT on extremely low-frequency electromagnetic field (ELF-EMF)-induced Nav activity in rat cerebellar granule cells (GCs). Exposing cerebellar GCs to ELF-EMF for 60 min. significantly increased the Nav current (INa ) densities by 62.5%. MT (5 μM) inhibited the ELF-EMF-induced INa increase. This inhibitory effect of MT is mimicked by an MT2 receptor agonist and was eliminated by an MT2 receptor antagonist. The Nav channel steady-state activation curve was significantly shifted towards hyperpolarization by ELF-EMF stimulation but remained unchanged by MT in cerebellar GC that were either exposed or not exposed to ELF-EMF. ELF-EMF exposure significantly increased the intracellular levels of phosphorylated PKA in cerebellar GCs, and both MT and IIK-7 did not reduce the ELF-EMF-induced increase in phosphorylated PKA. The inhibitory effects of MT on ELF-EMF-induced Nav activity was greatly reduced by the calmodulin inhibitor KN93. Calcium imaging showed that MT did not increase the basal intracellular Ca(2+) level, but it significantly elevated the intracellular Ca(2+) level evoked by the high K(+) stimulation in cerebellar GC that were either exposed or not exposed to ELF-EMF. In the presence of ruthenium red, a ryanodine-sensitive receptor blocker, the MT-induced increase in intracellular calcium levels was reduced. Our data show for the first time that MT protects against neuronal INa that result from ELF-EMF exposure through Ca(2+) influx-induced Ca(2+) release.
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Affiliation(s)
- Dong-Dong Liu
- School of Life Sciences, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
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Kim YC, Sim JH, Choi W, Kim CH, You RY, Xu WX, Lee SJ. Relaxant Effect of Spermidine on Acethylcholine and High K-induced Gastric Contractions of Guinea-Pig. Korean J Physiol Pharmacol 2008; 12:59-64. [PMID: 20157395 DOI: 10.4196/kjpp.2008.12.2.59] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In our previous study, we found that spermine and putrescine inhibited spontaneous and acetylcholine (ACh)-induced contractions of guinea-pig stomach via inhibition of L-type voltage-dependent calcium current (VDCC(L)). In this study, we also studied the effect of spermidine on mechanical contractions and calcium channel current (I(Ba)), and then compared its effects to those by spermine and putrescine. Spermidine inhibited spontaneous contraction of the gastric smooth muscle in a concentration-dependent manner (IC(50)=1.1+/-0.11 mM). Relationship between inhibition of contraction and calcium current by spermidine was studied using 50 mM high K(+)-induced contraction: Spermidine (5 mM) significantly reduced high K(+) (50 mM)-induced contraction to 37+/-4.7% of the control (p<0.05), and inhibitory effect of spermidine on I(Ba) was also observed at a wide range of test potential in current/voltage (I/V) relationship. Pre- and post-application of spermidine (5 mM) also significantly inhibited carbachol (CCh) and ACh-induced initial and phasic contractions. Finally, caffeine (10 mM)-induced contraction which is activated by Ca(2+)-induced Ca(2+) release (CICR),' was also inhibited by pretreatment of spermidine (5 mM). These findings suggest that spermidine inhibits spontaneous and CCh-induced contraction via inhibition of VDCC(L) and Ca(2+) releasing mechanism in guinea-pig stomach.
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Affiliation(s)
- Young Chul Kim
- Department of Physiology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea
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