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Bibollet H, Nguyen EL, Miranda DR, Ward CW, Voss AA, Schneider MF, Hernández‐Ochoa EO. Voltage sensor current, SR Ca 2+ release, and Ca 2+ channel current during trains of action potential-like depolarizations of skeletal muscle fibers. Physiol Rep 2023; 11:e15675. [PMID: 37147904 PMCID: PMC10163276 DOI: 10.14814/phy2.15675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 05/07/2023] Open
Abstract
In skeletal muscle, CaV 1.1 serves as the voltage sensor for both excitation-contraction coupling (ECC) and L-type Ca2+ channel activation. We have recently adapted the technique of action potential (AP) voltage clamp (APVC) to monitor the current generated by the movement of intramembrane voltage sensors (IQ ) during single imposed transverse tubular AP-like depolarization waveforms (IQAP ). We now extend this procedure to monitoring IQAP , and Ca2+ currents during trains of tubular AP-like waveforms in adult murine skeletal muscle fibers, and compare them with the trajectories of APs and AP-induced Ca2+ release measured in other fibers using field stimulation and optical probes. The AP waveform remains relatively constant during brief trains (<1 sec) for propagating APs in non-V clamped fibers. Trains of 10 AP-like depolarizations at 10 Hz (900 ms), 50 Hz (180 ms), or 100 Hz (90 ms) did not alter IQAP amplitude or kinetics, consistent with previous findings in isolated muscle fibers where negligible charge immobilization occurred during 100 ms step depolarizations. Using field stimulation, Ca2+ release did exhibit a considerable decline from pulse to pulse during the train, also consistent with previous findings, indicating that the decline of Ca2+ release during a short train of APs is not correlated to modification of charge movement. Ca2+ currents during single or 10 Hz trains of AP-like depolarizations were hardly detectable, were minimal during 50 Hz trains, and became more evident during 100 Hz trains in some fibers. Our results verify predictions on the behavior of the ECC machinery in response to AP-like depolarizations and provide a direct demonstration that Ca2+ currents elicited by single AP-like waveforms are negligible, but can become more prominent in some fibers during short high-frequency train stimulation that elicits maximal isometric force.
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Affiliation(s)
- Hugo Bibollet
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Elton L. Nguyen
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Daniel R. Miranda
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Christopher W. Ward
- Department of OrthopedicsUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Andrew A. Voss
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Martin F. Schneider
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Erick O. Hernández‐Ochoa
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
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2
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Dalle S, Schouten M, Meeus G, Slagmolen L, Koppo K. Molecular networks underlying cannabinoid signaling in skeletal muscle plasticity. J Cell Physiol 2022; 237:3517-3540. [PMID: 35862111 DOI: 10.1002/jcp.30837] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/01/2022] [Accepted: 07/08/2022] [Indexed: 11/07/2022]
Abstract
The cannabinoid system is ubiquitously present and is classically considered to engage in neural and immunity processes. Yet, the role of the cannabinoid system in the whole body and tissue metabolism via central and peripheral mechanisms is increasingly recognized. The present review provides insights in (i) how cannabinoid signaling is regulated via receptor-independent and -dependent mechanisms and (ii) how these signaling cascades (might) affect skeletal muscle plasticity and physiology. Receptor-independent mechanisms include endocannabinoid metabolism to eicosanoids and the regulation of ion channels. Alternatively, endocannabinoids can act as ligands for different classic (cannabinoid receptor 1 [CB1 ], CB2 ) and/or alternative (e.g., TRPV1, GPR55) cannabinoid receptors with a unique affinity, specificity, and intracellular signaling cascade (often tissue-specific). Antagonism of CB1 might hold clues to improve oxidative (mitochondrial) metabolism, insulin sensitivity, satellite cell growth, and muscle anabolism, whereas CB2 agonism might be a promising way to stimulate muscle metabolism and muscle cell growth. Besides, CB2 ameliorates muscle regeneration via macrophage polarization toward an anti-inflammatory phenotype, induction of MyoD and myogenin expression and antifibrotic mechanisms. Also TRPV1 and GPR55 contribute to the regulation of muscle growth and metabolism. Future studies should reveal how the cannabinoid system can be targeted to improve muscle quantity and/or quality in conditions such as ageing, disease, disuse, and metabolic dysregulation, taking into account challenges that are inherent to modulation of the cannabinoid system, such as central and peripheral side effects.
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Affiliation(s)
- Sebastiaan Dalle
- Department of Movement Sciences, Exercise Physiology Research Group, KU Leuven, Leuven, Belgium
| | - Moniek Schouten
- Department of Movement Sciences, Exercise Physiology Research Group, KU Leuven, Leuven, Belgium
| | - Gitte Meeus
- Department of Movement Sciences, Exercise Physiology Research Group, KU Leuven, Leuven, Belgium
| | - Lotte Slagmolen
- Department of Movement Sciences, Exercise Physiology Research Group, KU Leuven, Leuven, Belgium
| | - Katrien Koppo
- Department of Movement Sciences, Exercise Physiology Research Group, KU Leuven, Leuven, Belgium
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3
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Jaque-Fernández F, Jorquera G, Troc-Gajardo J, Pietri-Rouxel F, Gentil C, Buvinic S, Allard B, Jaimovich E, Jacquemond V, Casas M. Pannexin-1 and CaV1.1 show reciprocal interaction during excitation-contraction and excitation-transcription coupling in skeletal muscle. J Gen Physiol 2021; 153:212695. [PMID: 34636893 PMCID: PMC8515650 DOI: 10.1085/jgp.202012635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/24/2021] [Accepted: 09/15/2021] [Indexed: 01/18/2023] Open
Abstract
One of the most important functions of skeletal muscle is to respond to nerve stimuli by contracting. This function ensures body movement but also participates in other important physiological roles, like regulation of glucose homeostasis. Muscle activity is closely regulated to adapt to different demands and shows a plasticity that relies on both transcriptional activity and nerve stimuli. These two processes, both dependent on depolarization of the plasma membrane, have so far been regarded as separated and independent processes due to a lack of evidence of common protein partners or molecular mechanisms. In this study, we reveal intimate functional interactions between the process of excitation-induced contraction and the process of excitation-induced transcriptional activity in skeletal muscle. We show that the plasma membrane voltage-sensing protein CaV1.1 and the ATP-releasing channel Pannexin-1 (Panx1) regulate each other in a reciprocal manner, playing roles in both processes. Specifically, knockdown of CaV1.1 produces chronically elevated extracellular ATP concentrations at rest, consistent with disruption of the normal control of Panx1 activity. Conversely, knockdown of Panx1 affects not only activation of transcription but also CaV1.1 function on the control of muscle fiber contraction. Altogether, our results establish the presence of bidirectional functional regulations between the molecular machineries involved in the control of contraction and transcription induced by membrane depolarization of adult muscle fibers. Our results are important for an integrative understanding of skeletal muscle function and may impact our understanding of several neuromuscular diseases.
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Affiliation(s)
- Francisco Jaque-Fernández
- Programa de Fisiología y Biofísica, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Gonzalo Jorquera
- Programa de Fisiología y Biofísica, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile.,Centro de Neurobiología y Fisiopatología Integrativa, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jennifer Troc-Gajardo
- Programa de Fisiología y Biofísica, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - France Pietri-Rouxel
- Université Pierre et Marie Curie, Université Paris 06, Institut National de la Santé et de la Recherche Médicale/Centre National de la Recherche Scientifique/Institut de Myologie/Centre de Recherche en Myologie, Groupement hospitalier universitaire Pitié Salpêtrière, Paris, France
| | - Christel Gentil
- Université Pierre et Marie Curie, Université Paris 06, Institut National de la Santé et de la Recherche Médicale/Centre National de la Recherche Scientifique/Institut de Myologie/Centre de Recherche en Myologie, Groupement hospitalier universitaire Pitié Salpêtrière, Paris, France
| | - Sonja Buvinic
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - Bruno Allard
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
| | - Enrique Jaimovich
- Programa de Fisiología y Biofísica, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile.,Center for Exercise, Metabolism and Cancer, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Vincent Jacquemond
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
| | - Mariana Casas
- Programa de Fisiología y Biofísica, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile.,Center for Exercise, Metabolism and Cancer, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
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4
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Raifman TK, Kumar P, Haase H, Klussmann E, Dascal N, Weiss S. Protein kinase C enhances plasma membrane expression of cardiac L-type calcium channel, Ca V1.2. Channels (Austin) 2017; 11:604-615. [PMID: 28901828 DOI: 10.1080/19336950.2017.1369636] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
L-type-voltage-dependent Ca2+ channels (L-VDCCs; CaV1.2, α1C), crucial in cardiovascular physiology and pathology, are modulated via activation of G-protein-coupled receptors and subsequently protein kinase C (PKC). Despite extensive study, key aspects of the mechanisms leading to PKC-induced Ca2+ current increase are unresolved. A notable residue, Ser1928, located in the distal C-terminus (dCT) of α1C was shown to be phosphorylated by PKC. CaV1.2 undergoes posttranslational modifications yielding full-length and proteolytically cleaved CT-truncated forms. We have previously shown that, in Xenopus oocytes, activation of PKC enhances α1C macroscopic currents. This increase depended on the isoform of α1C expressed. Only isoforms containing the cardiac, long N-terminus (L-NT), were upregulated by PKC. Ser1928 was also crucial for the full effect of PKC. Here we report that, in Xenopus oocytes, following PKC activation the amount of α1C protein expressed in the plasma membrane (PM) increases within minutes. The increase in PM content is greater with full-length α1C than in dCT-truncated α1C, and requires Ser1928. The same was observed in HL-1 cells, a mouse atrium cell line natively expressing cardiac α1C, which undergoes the proteolytic cleavage of the dCT, thus providing a native setting for exploring the effects of PKC in cardiomyocytes. Interestingly, activation of PKC preferentially increased the PM levels of full-length, L-NT α1C. Our findings suggest that part of PKC regulation of CaV1.2 in the heart involves changes in channel's cellular fate. The mechanism of this PKC regulation appears to involve the C-terminus of α1C, possibly corroborating the previously proposed role of NT-CT interactions within α1C.
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Affiliation(s)
- Tal Keren Raifman
- a Department of Physiology and Pharmacology , Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel.,b Department of Physiotherapy , Zfat Academic College , Zfat , Israel
| | - Prabodh Kumar
- a Department of Physiology and Pharmacology , Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel
| | - Hannelore Haase
- c Max Delbruck Center for Molecular Medicine (MDC) , Berlin , Germany
| | - Enno Klussmann
- c Max Delbruck Center for Molecular Medicine (MDC) , Berlin , Germany
| | - Nathan Dascal
- a Department of Physiology and Pharmacology , Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel
| | - Sharon Weiss
- a Department of Physiology and Pharmacology , Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel
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5
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Aguennouz M, Lo Giudice C, Licata N, Rodolico C, Musumeci O, Fanin M, Migliorato A, Ragusa M, Macaione V, Di Giorgio RM, Angelini C, Toscano A. MicroRNA signatures predict dysregulated vitamin D receptor and calcium pathways status in limb girdle muscle dystrophies (LGMD) 2A/2B. Cell Biochem Funct 2017; 34:414-22. [PMID: 27558075 DOI: 10.1002/cbf.3202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/12/2016] [Accepted: 06/01/2016] [Indexed: 12/29/2022]
Abstract
miRNA expression profile and predicted pathways involved in selected limb-girdle muscular dystrophy (LGMD)2A/2B patients were investigated. A total of 187 miRNAs were dysregulated in all patients, with six miRNAs showing opposite regulation in LGMD2A versus LGMD2B patients. Silico analysis evidence: (1) a cluster of the dysregulated miRNAs resulted primarily involved in inflammation and calcium metabolism, and (2) two genes predicted as controlled by calcium-assigned miRNAs (Vitamin D Receptor gene and Guanine Nucleotide Binding protein beta polypeptide 1gene) showed an evident upregulation in LGMD2B patients, in accordance with miRNA levels. Our data support alterations in calcium pathway status in LGMD 2A/B, suggesting myofibre calcium imbalance as a potential therapeutic target. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- M Aguennouz
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - C Lo Giudice
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - N Licata
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - C Rodolico
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - O Musumeci
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - M Fanin
- Neurological Clinic, University of Padua, Italy
| | - A Migliorato
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - M Ragusa
- Department of Biomedical and Biotechnological Sciences Biology, Genetics and Bioinformatics Unit, University of Catania, Italy
| | - V Macaione
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - R M Di Giorgio
- Department of Clinical and Experimental Medicine, University of Messina, Italy
| | - C Angelini
- Neurological Clinic, University of Padua, Italy
| | - A Toscano
- Department of Clinical and Experimental Medicine, University of Messina, Italy
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6
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Oláh T, Bodnár D, Tóth A, Vincze J, Fodor J, Reischl B, Kovács A, Ruzsnavszky O, Dienes B, Szentesi P, Friedrich O, Csernoch L. Cannabinoid signalling inhibits sarcoplasmic Ca 2+ release and regulates excitation-contraction coupling in mammalian skeletal muscle. J Physiol 2016; 594:7381-7398. [PMID: 27641745 DOI: 10.1113/jp272449] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 09/14/2016] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS Marijuana was found to cause muscle weakness, although the exact regulatory role of its receptors (CB1 cannabinoid receptor; CB1R) in the excitation-contraction coupling (ECC) of mammalian skeletal muscle remains unknown. We found that CB1R activation or its knockout did not affect muscle force directly, whereas its activation decreased the Ca2+ -sensitivity of the contractile apparatus and made the muscle fibres more prone to fatigue. We demonstrate that CB1Rs are not connected to the inositol 1,4,5-trisphosphate pathway either in myotubes or in adult muscle fibres. By contrast, CB1Rs constitutively inhibit sarcoplasmic Ca2+ release and sarcoplasmic reticulum Ca2+ ATPase during ECC in a Gi/o protein-mediated way in adult skeletal muscle fibres but not in myotubes. These results help with our understanding of the physiological effects and pathological consequences of CB1R activation in skeletal muscle and may be useful in the development of new cannabinoid drugs. ABSTRACT Marijuana was found to cause muscle weakness, although it is unknown whether it affects the muscles directly or modulates only the motor control of the central nervous system. Although the presence of CB1 cannabinoid receptors (CB1R), which are responsible for the psychoactive effects of the drug in the brain, have recently been demonstrated in skeletal muscle, it is unclear how CB1R-mediated signalling affects the contraction and Ca²⁺ homeostasis of mammalian skeletal muscle. In the present study, we demonstrate that in vitro CB1R activation increased muscle fatigability and decreased the Ca2+ -sensitivity of the contractile apparatus, whereas it did not alter the amplitude of single twitch contractions. In myotubes, CB1R agonists neither evoked, nor influenced inositol 1,4,5-trisphosphate (IP3 )-mediated Ca2+ transients, nor did they alter excitation-contraction coupling. By contrast, in isolated muscle fibres of wild-type mice, although CB1R agonists did not evoke IP3 -mediated Ca2+ transients too, they significantly reduced the amplitude of the depolarization-evoked transients in a pertussis-toxin sensitive manner, indicating a Gi/o protein-dependent mechanism. Concurrently, on skeletal muscle fibres isolated from CB1R-knockout animals, depolarization-evoked Ca2+ transients, as well qas Ca2+ release flux via ryanodine receptors (RyRs), and the total amount of released Ca2+ was significantly greater than that from wild-type mice. Our results show that CB1R-mediated signalling exerts both a constitutive and an agonist-mediated inhibition on the Ca2+ transients via RyR, regulates the activity of the sarcoplasmic reticulum Ca2+ ATPase and enhances muscle fatigability, which might decrease exercise performance, thus playing a role in myopathies, and therefore should be considered during the development of new cannabinoid drugs.
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Affiliation(s)
- Tamás Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dóra Bodnár
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Adrienn Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Vincze
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Barbara Reischl
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Adrienn Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Olga Ruzsnavszky
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Szentesi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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7
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Abstract
The role of T-type calcium currents is rarely considered in the extensive literature covering the mechanisms of long-term synaptic plasticity. This situation reflects the lack of suitable T-type channel antagonists that till recently has hampered investigations of the functional roles of these channels. However, with the development of new pharmacological and genetic tools, a clear involvement of T-type channels in synaptic plasticity is starting to emerge. Here, we review a number of studies showing that T-type channels participate to numerous homo- and hetero-synaptic plasticity mechanisms that involve different molecular partners and both pre- and post-synaptic modifications. The existence of T-channel dependent and independent plasticity at the same synapse strongly suggests a subcellular localization of these channels and their partners that allows specific interactions. Moreover, we illustrate the functional importance of T-channel dependent synaptic plasticity in neocortex and thalamus.
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Affiliation(s)
- Nathalie Leresche
- a Sorbonne Universités, Université Pierre et Marie Curie (UPMC) UM119, CNRS UMR8246, INSERM U1130, Neuroscience Paris Seine (NPS) , Paris , France
| | - Régis C Lambert
- a Sorbonne Universités, Université Pierre et Marie Curie (UPMC) UM119, CNRS UMR8246, INSERM U1130, Neuroscience Paris Seine (NPS) , Paris , France
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8
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Abstract
BACKGROUND The role of cAMP in regulating T cell activation and function has been controversial. cAMP is generally known as an immunosuppressant, but it is also required for generating optimal immune responses. As the effect of cAMP is likely to depend on its cellular context, the current study investigated whether the mechanism of activation of Gαs and adenylyl cyclase influences their effect on T cell receptor (TCR)-stimulated interleukin-2 (IL-2) mRNA levels. METHODS The effect of blocking Gs-coupled receptor (GsPCR)-mediated Gs activation on TCR-stimulated IL-2 mRNA levels in CD4(+) T cells was compared with that of knocking down Gαs expression or inhibiting adenylyl cyclase activity. The effect of knocking down Gαs expression on TCR-stimulated cAMP accumulation was compared with that of blocking GsPCR signaling. RESULTS ZM-241385, an antagonist to the Gs-coupled A2A adenosine receptor (A2AR), enhanced TCR-stimulated IL-2 mRNA levels in primary human CD4(+) T helper cells and in Jurkat T cells. A dominant negative Gαs construct, GαsDN3, also enhanced TCR-stimulated IL-2 mRNA levels. Similar to GsPCR antagonists, GαsDN3 blocked GsPCR-dependent activation of both Gαs and Gβγ. In contrast, Gαs siRNA and 2',5'-dideoxyadenosine (ddA), an adenylyl cyclase inhibitor, decreased TCR-stimulated IL-2 mRNA levels. Gαs siRNA, but not GαsDN3, decreased TCR-stimulated cAMP synthesis. Potentiation of IL-2 mRNA levels by ZM-241385 required at least two days of TCR stimulation, and addition of ddA after three days of TCR stimulation enhanced IL-2 mRNA levels. CONCLUSIONS GsPCRs play an inhibitory role in the regulation of TCR-stimulated IL-2 mRNA levels whereas Gαs and cAMP can play a stimulatory one. Additionally, TCR-dependent activation of Gαs does not appear to involve GsPCRs. These results suggest that the context of Gαs/cAMP activation and the stage of T cell activation and differentiation determine the effect on TCR-stimulated IL-2 mRNA levels.
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9
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Berthier C, Kutchukian C, Bouvard C, Okamura Y, Jacquemond V. Depression of voltage-activated Ca2+ release in skeletal muscle by activation of a voltage-sensing phosphatase. J Gen Physiol 2015; 145:315-30. [PMID: 25825170 PMCID: PMC4380211 DOI: 10.1085/jgp.201411309] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 03/05/2015] [Indexed: 12/30/2022] Open
Abstract
Phosphoinositides act as signaling molecules in numerous cellular transduction processes, and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) regulates the function of several types of plasma membrane ion channels. We investigated the potential role of PtdIns(4,5)P2 in Ca(2+) homeostasis and excitation-contraction (E-C) coupling of mouse muscle fibers using in vivo expression of the voltage-sensing phosphatases (VSPs) Ciona intestinalis VSP (Ci-VSP) or Danio rerio VSP (Dr-VSP). Confocal images of enhanced green fluorescent protein-tagged Dr-VSP revealed a banded pattern consistent with VSP localization within the transverse tubule membrane. Rhod-2 Ca(2+) transients generated by 0.5-s-long voltage-clamp depolarizing pulses sufficient to elicit Ca(2+) release from the sarcoplasmic reticulum (SR) but below the range at which VSPs are activated were unaffected by the presence of the VSPs. However, in Ci-VSP-expressing fibers challenged by 5-s-long depolarizing pulses, the Ca(2+) level late in the pulse (3 s after initiation) was significantly lower at 120 mV than at 20 mV. Furthermore, Ci-VSP-expressing fibers showed a reversible depression of Ca(2+) release during trains, with the peak Ca(2+) transient being reduced by ∼30% after the application of 10 200-ms-long pulses to 100 mV. A similar depression was observed in Dr-VSP-expressing fibers. Cav1.1 Ca(2+) channel-mediated current was unaffected by Ci-VSP activation. In fibers expressing Ci-VSP and a pleckstrin homology domain fused with monomeric red fluorescent protein (PLCδ1PH-mRFP), depolarizing pulses elicited transient changes in mRFP fluorescence consistent with release of transverse tubule-bound PLCδ1PH domain into the cytosol; the voltage sensitivity of these changes was consistent with that of Ci-VSP activation, and recovery occurred with a time constant in the 10-s range. Our results indicate that the PtdIns(4,5)P2 level is tightly maintained in the transverse tubule membrane of the muscle fibers, and that VSP-induced depletion of PtdIns(4,5)P2 impairs voltage-activated Ca(2+) release from the SR. Because Ca(2+) release is thought to be independent from InsP3 signaling, the effect likely results from an interaction between PtdIns(4,5)P2 and a protein partner of the E-C coupling machinery.
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Affiliation(s)
- Christine Berthier
- Centre National de la Recherche Scientifique UMR 5534, Université Lyon 1, Centre de Génétique et de Physiologie Moléculaire et Cellulaire, 69100 Villeurbanne, France
| | - Candice Kutchukian
- Centre National de la Recherche Scientifique UMR 5534, Université Lyon 1, Centre de Génétique et de Physiologie Moléculaire et Cellulaire, 69100 Villeurbanne, France
| | - Clément Bouvard
- Centre National de la Recherche Scientifique UMR 5534, Université Lyon 1, Centre de Génétique et de Physiologie Moléculaire et Cellulaire, 69100 Villeurbanne, France
| | - Yasushi Okamura
- Laboratory of Integrative Physiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Vincent Jacquemond
- Centre National de la Recherche Scientifique UMR 5534, Université Lyon 1, Centre de Génétique et de Physiologie Moléculaire et Cellulaire, 69100 Villeurbanne, France
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10
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Yost EA, Hynes TR, Hartle CM, Ott BJ, Berlot CH. Inhibition of G-protein βγ signaling enhances T cell receptor-stimulated interleukin 2 transcription in CD4+ T helper cells. PLoS One 2015; 10:e0116575. [PMID: 25629163 PMCID: PMC4309538 DOI: 10.1371/journal.pone.0116575] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/10/2014] [Indexed: 01/23/2023] Open
Abstract
G-protein-coupled receptor (GPCR) signaling modulates the expression of cytokines that are drug targets for immune disorders. However, although GPCRs are common targets for other diseases, there are few GPCR-based pharmaceuticals for inflammation. The purpose of this study was to determine whether targeting G-protein βγ (Gβγ) complexes could provide a useful new approach for modulating interleukin 2 (IL-2) levels in CD4+ T helper cells. Gallein, a small molecule inhibitor of Gβγ, increased levels of T cell receptor (TCR)-stimulated IL-2 mRNA in primary human naïve and memory CD4+ T helper cells and in Jurkat human CD4+ leukemia T cells. Gβ1 and Gβ2 mRNA accounted for >99% of Gβ mRNA, and small interfering RNA (siRNA)-mediated silencing of Gβ1 but not Gβ2 enhanced TCR-stimulated IL-2 mRNA increases. Blocking Gβγ enhanced TCR-stimulated increases in IL-2 transcription without affecting IL-2 mRNA stability. Blocking Gβγ also enhanced TCR-stimulated increases in nuclear localization of nuclear factor of activated T cells 1 (NFAT1), NFAT transcriptional activity, and levels of intracellular Ca2+. Potentiation of IL-2 transcription required continuous Gβγ inhibition during at least two days of TCR stimulation, suggesting that induction or repression of additional signaling proteins during T cell activation and differentiation might be involved. The potentiation of TCR-stimulated IL-2 transcription that results from blocking Gβγ in CD4+ T helper cells could have applications for autoimmune diseases.
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Affiliation(s)
- Evan A. Yost
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, 17822-2623, United States of America
| | - Thomas R. Hynes
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, 17822-2623, United States of America
| | - Cassandra M. Hartle
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, 17822-2623, United States of America
| | - Braden J. Ott
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, 17822-2623, United States of America
| | - Catherine H. Berlot
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, 17822-2623, United States of America
- * E-mail:
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11
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Proft J, Weiss N. G protein regulation of neuronal calcium channels: back to the future. Mol Pharmacol 2014; 87:890-906. [PMID: 25549669 DOI: 10.1124/mol.114.096008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/30/2014] [Indexed: 11/22/2022] Open
Abstract
Neuronal voltage-gated calcium channels have evolved as one of the most important players for calcium entry into presynaptic endings responsible for the release of neurotransmitters. In turn, and to fine-tune synaptic activity and neuronal communication, numerous neurotransmitters exert a potent negative feedback over the calcium signal provided by G protein-coupled receptors. This regulation pathway of physiologic importance is also extensively exploited for therapeutic purposes, for instance in the treatment of neuropathic pain by morphine and other μ-opioid receptor agonists. However, despite more than three decades of intensive research, important questions remain unsolved regarding the molecular and cellular mechanisms of direct G protein inhibition of voltage-gated calcium channels. In this study, we revisit this particular regulation and explore new considerations.
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Affiliation(s)
- Juliane Proft
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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12
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Casas M, Buvinic S, Jaimovich E. ATP signaling in skeletal muscle: from fiber plasticity to regulation of metabolism. Exerc Sport Sci Rev 2014; 42:110-6. [PMID: 24949845 DOI: 10.1249/jes.0000000000000017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Tetanic electrical stimulation releases adenosine triphosphate (ATP) from muscle fibers through pannexin-1 channels in a frequency-dependent manner; extracellular ATP activates signals that ultimately regulate gene expression and is able to increase glucose transport through activation of P2Y receptors, phosphatidylinositol 3-kinase, Akt, and AS160. We hypothesize that this mechanism is an important link between exercise and the regulation of muscle fiber plasticity and metabolism.
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Affiliation(s)
- Mariana Casas
- 1Center for Molecular Studies of the Cell, Biomedical Sciences Institute, Faculty of Medicine, Universidad de Chile; and 2Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
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13
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Zhang CH, Lifshitz LM, Uy KF, Ikebe M, Fogarty KE, ZhuGe R. The cellular and molecular basis of bitter tastant-induced bronchodilation. PLoS Biol 2013; 11:e1001501. [PMID: 23472053 PMCID: PMC3589262 DOI: 10.1371/journal.pbio.1001501] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/24/2013] [Indexed: 01/13/2023] Open
Abstract
Bitter tastants can activate bitter taste receptors on constricted smooth muscle cells to inhibit L-type calcium channels and induce bronchodilation. Bronchodilators are a standard medicine for treating airway obstructive diseases, and β2 adrenergic receptor agonists have been the most commonly used bronchodilators since their discovery. Strikingly, activation of G-protein-coupled bitter taste receptors (TAS2Rs) in airway smooth muscle (ASM) causes a stronger bronchodilation in vitro and in vivo than β2 agonists, implying that new and better bronchodilators could be developed. A critical step towards realizing this potential is to understand the mechanisms underlying this bronchodilation, which remain ill-defined. An influential hypothesis argues that bitter tastants generate localized Ca2+ signals, as revealed in cultured ASM cells, to activate large-conductance Ca2+-activated K+ channels, which in turn hyperpolarize the membrane, leading to relaxation. Here we report that in mouse primary ASM cells bitter tastants neither evoke localized Ca2+ events nor alter spontaneous local Ca2+ transients. Interestingly, they increase global intracellular [Ca2+]i, although to a much lower level than bronchoconstrictors. We show that these Ca2+ changes in cells at rest are mediated via activation of the canonical bitter taste signaling cascade (i.e., TAS2R-gustducin-phospholipase Cβ [PLCβ]- inositol 1,4,5-triphosphate receptor [IP3R]), and are not sufficient to impact airway contractility. But activation of TAS2Rs fully reverses the increase in [Ca2+]i induced by bronchoconstrictors, and this lowering of the [Ca2+]i is necessary for bitter tastant-induced ASM cell relaxation. We further show that bitter tastants inhibit L-type voltage-dependent Ca2+ channels (VDCCs), resulting in reversal in [Ca2+]i, and this inhibition can be prevented by pertussis toxin and G-protein βγ subunit inhibitors, but not by the blockers of PLCβ and IP3R. Together, we suggest that TAS2R stimulation activates two opposing Ca2+ signaling pathways via Gβγ to increase [Ca2+]i at rest while blocking activated L-type VDCCs to induce bronchodilation of contracted ASM. We propose that the large decrease in [Ca2+]i caused by effective tastant bronchodilators provides an efficient cell-based screening method for identifying potent dilators from among the many thousands of available bitter tastants. Bitter taste receptors (TAS2Rs), a G-protein-coupled receptor family long thought to be solely expressed in taste buds on the tongue, have recently been detected in airways. Bitter substances can activate TAS2Rs in airway smooth muscle to cause greater bronchodilation than β2 adrenergic receptor agonists, the most commonly used bronchodilators. However, the mechanisms underlying this bronchodilation remain elusive. Here we show that, in resting primary airway smooth muscle cells, bitter tastants activate a TAS2R-dependent signaling pathway that results in an increase in intracellular calcium levels, albeit to a level much lower than that produced by bronchoconstrictors. In bronchoconstricted cells, however, bitter tastants reverse the bronchoconstrictor-induced increase in calcium levels, which leads to the relaxation of smooth muscle cells. We find that this reversal is due to inhibition of L-type calcium channels. Our results suggest that under normal conditions, bitter tastants can activate TAS2Rs to modestly increase calcium levels, but that when smooth muscle cells are constricted, they can block L-type calcium channels to induce bronchodilation. We postulate that this novel mechanism could operate in other extraoral cells expressing TAS2Rs.
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Affiliation(s)
- Cheng-Hai Zhang
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Lawrence M. Lifshitz
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Karl F. Uy
- Department of Surgery, Division of Thoracic Surgery, University of Massachusetts Memorial Medical Center, Worcester, Massachusetts, United States of America
| | - Mitsuo Ikebe
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Kevin E. Fogarty
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Ronghua ZhuGe
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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14
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Lefebvre R, Legrand C, Groom L, Dirksen RT, Jacquemond V. Ca2+ release in muscle fibers expressing R4892W and G4896V type 1 ryanodine receptor disease mutants. PLoS One 2013; 8:e54042. [PMID: 23308296 PMCID: PMC3538700 DOI: 10.1371/journal.pone.0054042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 12/05/2012] [Indexed: 12/17/2022] Open
Abstract
The large and rapidly increasing number of potentially pathological mutants in the type 1 ryanodine receptor (RyR1) prompts the need to characterize their effects on voltage-activated sarcoplasmic reticulum (SR) Ca2+ release in skeletal muscle. Here we evaluated the function of the R4892W and G4896V RyR1 mutants, both associated with central core disease (CCD) in humans, in myotubes and in adult muscle fibers. For both mutants expressed in RyR1-null (dyspedic) myotubes, voltage-gated Ca2+ release was absent following homotypic expression and only partially restored following heterotypic expression with wild-type (WT) RyR1. In muscle fibers from adult WT mice, both mutants were expressed in restricted regions of the fibers with a pattern consistent with triadic localization. Voltage-clamp-activated confocal Ca2+ signals showed that fiber regions endowed with G4896V-RyR1s exhibited an ∼30% reduction in the peak rate of SR Ca2+ release, with no significant change in SR Ca2+ content. Immunostaining revealed no associated change in the expression of either α1S subunit (Cav1.1) of the dihydropyridine receptor (DHPR) or type 1 sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA1), indicating that the reduced Ca2+ release resulted from defective RyR1 function. Interestingly, in spite of robust localized junctional expression, the R4892W mutant did not affect SR Ca2+ release in adult muscle fibers, consistent with a low functional penetrance of this particular CCD-associated mutant.
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Affiliation(s)
- Romain Lefebvre
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534 – Université Lyon 1, Villeurbanne, France
| | - Claude Legrand
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534 – Université Lyon 1, Villeurbanne, France
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Robert T. Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Vincent Jacquemond
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534 – Université Lyon 1, Villeurbanne, France
- * E-mail:
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