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Amjid U, Aziz U, Habib U, Jabeen I. Biological regulatory network analysis for targeting the mitochondrial calcium uniporter (MCU) mediated calcium (Ca 2+) transport in neurodegenerative disorders. Cell Biochem Funct 2024; 42:e4082. [PMID: 38944766 DOI: 10.1002/cbf.4082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/30/2024] [Accepted: 06/18/2024] [Indexed: 07/01/2024]
Abstract
Calcium (Ca2+) has been observed as the most important ion involved in a series of cellular processes and its homeostasis is critical for normal cellular functions. Mitochondrial calcium uniporter (MCU) complex has been recognized as the most important calcium-specific channel located in the inner mitochondrial membrane and is one of the major players in maintaining the Ca2+ homeostasis by transporting Ca2+ across the mitochondrial membrane. Furthermore, dysregulation of the mitochondrial Ca2+ homeostasis has been orchestrated to neurodegenerative response. This necessitates quantitative evaluation of the MCU-dependent mROS production and subsequent cellular responses for more specific therapeutic interventions against neurodegenerative disorders. Towards this goal, here we present a biological regulatory network of MCU to dynamically simulate the MCU-mediated ROS production and its response in neurodegeneration. Previously, ruthenium complex RuRed and its derivatives have been reported to show low nM to high µM potency against MCU to maintain cytosolic Ca2+ (cCa2+) homeostasis by modulating mitochondrial Ca2+ (mCa2+) uptake. Therefore, structural modeling and dynamic simulation of MCU pore-forming subunit is performed to probe the interaction profiling of previously reported Ru265 and its derivatives compounds with MCU. The current study highlighted MCU as a potential drug target in neurodegenerative disorders. Furthermore, ASP261 and GLU264 amino acid residues in DIME motif of MCU pore-forming subunits are identified as crucial for modulating the activity of MCU in neurodegenerative disorders.
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Affiliation(s)
- Umar Amjid
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
- Department of Paediatrics and Child Health, Medical College, Aga Khan University Hospital, Karachi, Pakistan
| | - Ubair Aziz
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Uzma Habib
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
| | - Ishrat Jabeen
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences & Technology (NUST), Islamabad, Pakistan
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2
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Villarino NW, Hamed YMF, Ghosh B, Dubin AE, Lewis AH, Odem MA, Loud MC, Wang Y, Servin-Vences MR, Patapoutian A, Marshall KL. Labeling PIEZO2 activity in the peripheral nervous system. Neuron 2023; 111:2488-2501.e8. [PMID: 37321223 PMCID: PMC10527906 DOI: 10.1016/j.neuron.2023.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 03/24/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023]
Abstract
Sensory neurons detect mechanical forces from both the environment and internal organs to regulate physiology. PIEZO2 is a mechanosensory ion channel critical for touch, proprioception, and bladder stretch sensation, yet its broad expression in sensory neurons suggests it has undiscovered physiological roles. To fully understand mechanosensory physiology, we must know where and when PIEZO2-expressing neurons detect force. The fluorescent styryl dye FM 1-43 was previously shown to label sensory neurons. Surprisingly, we find that the vast majority of FM 1-43 somatosensory neuron labeling in mice in vivo is dependent on PIEZO2 activity within the peripheral nerve endings. We illustrate the potential of FM 1-43 by using it to identify novel PIEZO2-expressing urethral neurons that are engaged by urination. These data reveal that FM 1-43 is a functional probe for mechanosensitivity via PIEZO2 activation in vivo and will facilitate the characterization of known and novel mechanosensory processes in multiple organ systems.
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Affiliation(s)
- Nicholas W Villarino
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Yasmeen M F Hamed
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Development, Disease Models, and Therapeutics, Baylor College of Medicine, Houston, TX 77030
| | - Britya Ghosh
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adrienne E Dubin
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Amanda H Lewis
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Max A Odem
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meaghan C Loud
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Yu Wang
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - M Rocio Servin-Vences
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ardem Patapoutian
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Kara L Marshall
- Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.
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3
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van der Laarse WJ, Bogaards SJP, Schalij I, Vonk Noordegraaf A, Vaz FM, van Groen D. Work and oxygen consumption of isolated right ventricular papillary muscle in experimental pulmonary hypertension. J Physiol 2022; 600:4465-4484. [PMID: 35993114 DOI: 10.1113/jp282991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/12/2022] [Indexed: 11/08/2022] Open
Abstract
Right-sided myocardial mechanical efficiency (work output/metabolic energy input) in pulmonary hypertension can be severely reduced. We determined the contribution of intrinsic myocardial determinants of efficiency using papillary muscle preparations from monocrotaline-induced pulmonary hypertensive (MCT-PH) rats. The hypothesis tested was that efficiency is reduced by mitochondrial dysfunction in addition to increased activation heat reported previously. Right ventricular muscle preparations were subjected to 5 Hz sinusoidal length changes at 37°C. Work and suprabasal oxygen consumption (V ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ ) were measured before and after cross-bridge inhibition by blebbistatin. Cytosolic cytochrome c concentration, myocyte cross-sectional area, proton permeability of the inner mitochondrial membrane and monoamine oxidase and glucose 6-phosphate dehydrogenase activities and phosphatidylglycerol/cardiolipin contents were determined. Mechanical efficiency ranged from 23% to 11% in control (n = 6) and from 22% to 1% in MCT-PH (n = 15) and correlated with work (r2 = 0.68, P < 0.0001) but not withV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ (r2 = 0.004, P = 0.7919).V ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ for cross-bridge cycling was proportional to work (r2 = 0.56, P = 0.0005). Blebbistatin-resistantV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ (r2 = 0.32, P = 0.0167) and proton permeability of the mitochondrial inner membrane (r2 = 0.36, P = 0.0110) correlated inversely with efficiency. Together, these variables explained the variance of efficiency (coefficient of multiple determination r2 = 0.79, P = 0.0001). Cytosolic cytochrome c correlated inversely with work (r2 = 0.28, P = 0.0391), but not with efficiency (r2 = 0.20, P = 0.0867). Glucose 6-phosphate dehydrogenase, monoamine oxidase and phosphatidylglycerol/cardiolipin increased in the right ventricular wall of MCT-PH but did not correlate with efficiency. Reduced myocardial efficiency in MCT-PH is a result of activation processes and mitochondrial dysfunction. The variance of work and the ratio of activation heat reported previously and blebbistatin-resistantV ̇ O 2 ${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ are discussed. KEY POINTS: Mechanical efficiency of right ventricular myocardium is reduced in pulmonary hypertension. Increased energy use for activation processes has been demonstrated previously, but the contribution of mitochondrial dysfunction is unknown. Work and oxygen consumption are determined during work loops. Oxygen consumption for activation and cross-bridge cycling confirm the previous heat measurements. Cytosolic cytochrome c concentration, proton permeability of the mitochondrial inner membrane and phosphatidylglycerol/cardiolipin are increased in experimental pulmonary hypertension. Reduced work and mechanical efficiency are related to mitochondrial dysfunction. Upregulation of the pentose phosphate pathway and a potential gap in the energy balance suggest mitochondrial dysfunction in right ventricular overload is a resiult of the excessive production of reactive oxygen species.
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Affiliation(s)
- Willem J van der Laarse
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Sylvia J P Bogaards
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Ingrid Schalij
- Department of Pulmonology, Amsterdam Cardiovascular Sciences, VU University Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Anton Vonk Noordegraaf
- Department of Pulmonology, Amsterdam Cardiovascular Sciences, VU University Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Frédéric M Vaz
- Amsterdam Cardiovascular Sciences, VU University Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands and Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Department of Clinical Chemistry, Amsterdam Gastroentrology Endocrinology Metabolism, Amsterdam, Department of Pediatrics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
- Emma Children's Hospital, Amsterdam University Medical Centers, Core Facility Metabolomics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Duncan van Groen
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Amsterdam, Amsterdam University Medical Centers, Amsterdam, The Netherlands
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Filho FC, Silva JDP, Petri C, Almendra JSL, de Sousa ÍA, Cavalcanti SMG, Silva BA, Formiga Melo MF, Cavalcanti PMDS. Pharmacological evidence that GABA-induced relaxation of rat proximal duodenum longitudinal muscle depends on NKCC cotransporter activity and Ca 2+ influx. Can J Physiol Pharmacol 2022; 100:728-740. [PMID: 35880679 DOI: 10.1139/cjpp-2021-0639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in adult central nervous system (CNS) synapses, but it excites immature CNS neurons as well as neurons in the myenteric plexus. The present work aimed to determine whether GABA-induced nonadrenergic, noncholinergic (NANC) neuronal-mediated relaxation of the rat duodenum is dependent on the activity of Na+ K+ Cl- cotransporters (NKCC) and requires calcium influx. In the presence of guanethidine (3 µmol/L), atropine (3 µmol/L), and indomethacin (1 µmol/L), relaxations induced by GABA (100 µmol/L), KCl (5-10 mmol/L) and electrical field stimulation (1-8 Hz, 2 ms, 60 V), but not those induced by bradykinin (10-100 nmol/L) were abolished by lidocaine (300 µmol/L). However, only GABA-induced relaxations were reduced in a concentration-dependent manner by the NKCC1/2 inhibitors bumetanide (0.1-1 µmol/L) and furosemide (1-10 µmol/L). GABA-induced NANC neuronal relaxation was abolished by bicuculline (30 µmol/L) and inhibited by N-nitroarginine methyl ester (l-NAME, 300 µmol/L). The ω-conotoxin GVIA (1 µmol/L), which acts exclusively on neuronal CaV2 channels, but not on smooth muscle voltage-gated Ca2+ CaV1 channels, and nonselective blockers of these channels (verapamil 100 nmol/L and ruthenium red 10 µmol/L), reduced GABA-induced relaxations. These results showed that the activation of GABAA receptors induces NANC nitrergic neuronal relaxations in the rat duodenum, which depend on NKCC activity and CaV2 channel activation, suggesting that this phenomenon results from neuronal depolarization promoted by Cl- efflux through GABAA receptors, with subsequent Ca2+ influx and nitric oxide release.
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Affiliation(s)
- Francisco Chagas Filho
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - Janyerson Dannys Pereira Silva
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - Caio Petri
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - João Santos Lima Almendra
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - Ícaro Araújo de Sousa
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | | | - Bagnólia A Silva
- Pharmacological Sciences Department, 58051-900, Health Sciences Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Margareth Fátima Formiga Melo
- Pharmacological Sciences Department, 58051-900, Health Sciences Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
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Garbincius JF, Luongo TS, Jadiya P, Hildebrand AN, Kolmetzky DW, Mangold AS, Roy R, Ibetti J, Nwokedi M, Koch WJ, Elrod JW. Enhanced NCLX-dependent mitochondrial Ca 2+ efflux attenuates pathological remodeling in heart failure. J Mol Cell Cardiol 2022; 167:52-66. [PMID: 35358843 PMCID: PMC9107512 DOI: 10.1016/j.yjmcc.2022.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 02/17/2022] [Accepted: 03/07/2022] [Indexed: 02/08/2023]
Abstract
Mitochondrial calcium (mCa2+) uptake couples changes in cardiomyocyte energetic demand to mitochondrial ATP production. However, excessive mCa2+ uptake triggers permeability transition and necrosis. Despite these established roles during acute stress, the involvement of mCa2+ signaling in cardiac adaptations to chronic stress remains poorly defined. Changes in NCLX expression are reported in heart failure (HF) patients and models of cardiac hypertrophy. Therefore, we hypothesized that altered mCa2+ homeostasis contributes to the hypertrophic remodeling of the myocardium that occurs upon a sustained increase in cardiac workload. The impact of mCa2+ flux on cardiac function and remodeling was examined by subjecting mice with cardiomyocyte-specific overexpression (OE) of the mitochondrial Na+/Ca2+ exchanger (NCLX), the primary mediator of mCa2+ efflux, to several well-established models of hypertrophic and non-ischemic HF. Cardiomyocyte NCLX-OE preserved contractile function, prevented hypertrophy and fibrosis, and attenuated maladaptive gene programs in mice subjected to chronic pressure overload. Hypertrophy was attenuated in NCLX-OE mice, prior to any decline in cardiac contractility. NCLX-OE similarly attenuated deleterious cardiac remodeling in mice subjected to chronic neurohormonal stimulation. However, cardiomyocyte NCLX-OE unexpectedly reduced overall survival in mice subjected to severe neurohormonal stress with angiotensin II + phenylephrine. Adenoviral NCLX expression limited mCa2+ accumulation, oxidative metabolism, and de novo protein synthesis during hypertrophic stimulation of cardiomyocytes in vitro. Our findings provide genetic evidence for the contribution of mCa2+ to early pathological remodeling in non-ischemic heart disease, but also highlight a deleterious consequence of increasing mCa2+ efflux when the heart is subjected to extreme, sustained neurohormonal stress.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Timothy S Luongo
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Pooja Jadiya
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Alycia N Hildebrand
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Devin W Kolmetzky
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Adam S Mangold
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Rajika Roy
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Jessica Ibetti
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Mary Nwokedi
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Walter J Koch
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - John W Elrod
- Center for Translational Medicine, Department of Cardiovascular Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
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Mechanotransduction channel Piezo is widely expressed in the spider, Cupiennius salei, mechanosensory neurons and central nervous system. Sci Rep 2021; 11:7994. [PMID: 33846502 PMCID: PMC8042031 DOI: 10.1038/s41598-021-87202-1] [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: 11/27/2020] [Accepted: 03/25/2021] [Indexed: 01/01/2023] Open
Abstract
Mechanosensory neurons use mechanotransduction (MET) ion channels to detect mechanical forces and displacements. Proteins that function as MET channels have appeared multiple times during evolution and occur in at least four different families: the DEG/ENaC and TRP channels, as well as the TMC and Piezo proteins. We found twelve putative members of MET channel families in two spider transcriptomes, but detected only one, the Piezo protein, by in situ hybridization in their mechanosensory neurons. In contrast, probes for orthologs of TRP, ENaC or TMC genes that code MET channels in other species did not produce any signals in these cells. An antibody against C. salei Piezo detected the protein in all parts of their mechanosensory cells and in many neurons of the CNS. Unspecific blockers of MET channels, Ruthenium Red and GsMTx4, had no effect on the mechanically activated currents of the mechanosensory VS-3 neurons, but the latter toxin reduced action potential firing when these cells were stimulated electrically. The Piezo protein is expressed throughout the spider nervous system including the mechanosensory neurons. It is possible that it contributes to mechanosensory transduction in spider mechanosensilla, but it must have other functions in peripheral and central neurons.
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O'Rourke B, Ashok D, Liu T. Mitochondrial Ca 2+ in heart failure: Not enough or too much? J Mol Cell Cardiol 2020; 151:126-134. [PMID: 33290770 DOI: 10.1016/j.yjmcc.2020.11.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/18/2020] [Accepted: 11/28/2020] [Indexed: 01/04/2023]
Abstract
Ca2+ serves as a ubiquitous second messenger mediating a variety of cellular processes including electrical excitation, contraction, gene expression, secretion, cell death and others. The identification of the molecular components of the mitochondrial Ca2+ influx and efflux pathways has created a resurgent interest in the regulation of mitochondrial Ca2+ balance and its physiological and pathophysiological roles. While the pace of discovery has quickened with the availability of new cellular and animal models, many fundamental questions remain to be answered regarding the regulation and functional impact of mitochondrial Ca2+ in health and disease. This review highlights several experimental observations pertaining to key aspects of mitochondrial Ca2+ homeostasis that remain enigmatic, particularly whether mitochondrial Ca2+ signaling is depressed or excessive in heart failure, which will determine the optimal approach to therapeutic intervention.
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Affiliation(s)
- Brian O'Rourke
- The Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, MD 21205, USA.
| | - Deepthi Ashok
- The Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, MD 21205, USA
| | - Ting Liu
- The Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, MD 21205, USA
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Jegal HG, Park HJ, Kim JW, Yang SG, Kim MJ, Koo DB. Ruthenium red improves blastocyst developmental competence by regulating mitochondrial Ca 2+ and mitochondrial functions in fertilized porcine oocytes in vitro. J Reprod Dev 2020; 66:377-386. [PMID: 32321875 PMCID: PMC7470902 DOI: 10.1262/jrd.2020-013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ruthenium red (RR) inhibits calcium (Ca2+) entry from the cytoplasm to the mitochondria, and is involved in maintenance of Ca2+ homeostasis in mammalian
cells. Ca2+ homeostasis is very important for further embryonic development of fertilized oocytes. However, the effect of RR on mitochondria-Ca2+
(mito-Ca2+) levels during in vitro fertilization (IVF) on subsequent blastocyst developmental capacity in porcine is unclear. The present study
explored the regulation of mito-Ca2+ levels using RR and/or histamine in fertilized oocytes and their influence on blastocyst developmental capacity in pigs. Red
fluorescence intensity by the mito-Ca2+ detection dye Rhod-2 was significantly increased (P < 0.05) in zygotes 6 h after IVF compared to mature oocytes. Based on
these results, we investigated the changes in mito-Ca2+ by RR (10 and 20 μM) in presumptive zygotes using Rhod-2 staining and mito-Ca2+ uptake 1 (MICU1)
protein levels as an indicator of mito-Ca2+ uptake using western blot analysis. As expected, RR-treated zygotes displayed decreased protein levels of MICU1 and Rhod-2
red fluorescence intensity compared to non-treated zygotes 6 h after IVF. Blastocyst development rate of 20 μM RR-treated zygotes was significantly increased 6 h after IVF (P <
0.05) due to improved mitochondrial functions. Conversely, the blastocyst development rate was significantly decreased in histamine (mito-Ca2+ inhibitor, 100 nM) treated
zygotes (P < 0.05). The collective results demonstrate that RR improves blastocyst development in porcine embryos by regulating mito-Ca2+ and MICU1 expression
following IVF.
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Affiliation(s)
- Ho-Geun Jegal
- Department of Biotechnology, College of Engineering, Daegu University, Gyeongbuk 38453, Republic of Korea.,Institute of Infertility, Daegu University, Gyeongbuk 38453, Republic of Korea
| | - Hyo-Jin Park
- Department of Biotechnology, College of Engineering, Daegu University, Gyeongbuk 38453, Republic of Korea.,Institute of Infertility, Daegu University, Gyeongbuk 38453, Republic of Korea
| | - Jin-Woo Kim
- Department of Biotechnology, College of Engineering, Daegu University, Gyeongbuk 38453, Republic of Korea.,Institute of Infertility, Daegu University, Gyeongbuk 38453, Republic of Korea
| | - Seul-Gi Yang
- Department of Biotechnology, College of Engineering, Daegu University, Gyeongbuk 38453, Republic of Korea.,Institute of Infertility, Daegu University, Gyeongbuk 38453, Republic of Korea
| | - Min-Ji Kim
- Department of Biotechnology, College of Engineering, Daegu University, Gyeongbuk 38453, Republic of Korea.,Institute of Infertility, Daegu University, Gyeongbuk 38453, Republic of Korea
| | - Deog-Bon Koo
- Department of Biotechnology, College of Engineering, Daegu University, Gyeongbuk 38453, Republic of Korea.,Institute of Infertility, Daegu University, Gyeongbuk 38453, Republic of Korea
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9
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Garbincius JF, Luongo TS, Elrod JW. The debate continues - What is the role of MCU and mitochondrial calcium uptake in the heart? J Mol Cell Cardiol 2020; 143:163-174. [PMID: 32353353 DOI: 10.1016/j.yjmcc.2020.04.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/15/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Since the identification of the mitochondrial calcium uniporter (MCU) in 2011, several studies utilizing genetic models have attempted to decipher the role of mitochondrial calcium uptake in cardiac physiology. Confounding results in various mutant mouse models have led to an ongoing debate regarding the function of MCU in the heart. In this review, we evaluate and discuss the totality of evidence for mitochondrial calcium uptake in the cardiac stress response and highlight recent reports that implicate MCU in the control of homeostatic cardiac metabolism and function. This review concludes with a discussion of current gaps in knowledge and remaining experiments to define how MCU contributes to contractile function, cell death, metabolic regulation, and heart failure progression.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - Timothy S Luongo
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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10
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Roberts MWG, Sui G, Wu R, Rong W, Wildman S, Montgomery B, Ali A, Langley S, Ruggieri MR, Wu C. TRPV4 receptor as a functional sensory molecule in bladder urothelium: Stretch-independent, tissue-specific actions and pathological implications. FASEB J 2020; 34:263-286. [PMID: 31914645 PMCID: PMC6973053 DOI: 10.1096/fj.201900961rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 09/26/2019] [Accepted: 09/30/2019] [Indexed: 12/02/2022]
Abstract
The newly recognized sensory role of bladder urothelium has generated intense interest in identifying its novel sensory molecules. Sensory receptor TRPV4 may serve such function. However, specific and physiologically relevant tissue actions of TRPV4, stretch-independent responses, and underlying mechanisms are unknown and its role in human conditions has not been examined. Here we showed TRPV4 expression in guinea-pig urothelium, suburothelium, and bladder smooth muscle, with urothelial predominance. Selective TRPV4 activation without stretch evoked significant ATP release-key urothelial sensory process, from live mucosa tissue, full-thickness bladder but not smooth muscle, and sustained muscle contractions. ATP release was mediated by Ca2+-dependent, pannexin/connexin-conductive pathway involving protein tyrosine kinase, but independent from vesicular transport and chloride channels. TRPV4 activation generated greater Ca2+ rise than purinergic activation in urothelial cells. There was intrinsic TRPV4 activity without exogeneous stimulus, causing ATP release. TRPV4 contributed to 50% stretch-induced ATP release. TRPV4 activation also triggered superoxide release. TRPV4 expression was increased with aging. Human bladder mucosa presented similarities to guinea pigs. Overactive bladders exhibited greater TRPV4-induced ATP release with age dependence. These data provide the first evidence in humans for the key functional role of TRPV4 in urothelium with specific mechanisms and identify TRPV4 up-regulation in aging and overactive bladders.
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Affiliation(s)
| | - Guiping Sui
- Guy's and St Thomas Hospitals NHS TrustLondonUK
| | - Rui Wu
- University Hospitals Coventry and Warwickshire NHS TrustCoventryUK
| | - Weifang Rong
- Department of PhysiologyShanghai Jiaotong University School of MedicineShanghaiChina
| | | | | | | | | | | | - Changhao Wu
- School of Biosciences and MedicineUniversity of SurreyGuildfordUK
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Zhang L, Wang H, Zhou X, Mao L, Ding K, Hu Z. Role of mitochondrial calcium uniporter-mediated Ca 2+ and iron accumulation in traumatic brain injury. J Cell Mol Med 2019; 23:2995-3009. [PMID: 30756474 PMCID: PMC6433723 DOI: 10.1111/jcmm.14206] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 12/28/2018] [Accepted: 01/16/2019] [Indexed: 12/17/2022] Open
Abstract
Previous studies have suggested that the cellular Ca2+ and iron homeostasis, which can be regulated by mitochondrial calcium uniporter (MCU), is associated with oxidative stress, apoptosis and many neurological diseases. However, little is known about the role of MCU‐mediated Ca2+ and iron accumulation in traumatic brain injury (TBI). Under physiological conditions, MCU can be inhibited by ruthenium red (RR) and activated by spermine (Sper). In the present study, we used RR and Sper to reveal the role of MCU in mouse and neuron TBI models. Our results suggested that the Ca2+ and iron concentrations were obviously increased after TBI. In addition, TBI models showed a significant generation of reactive oxygen species (ROS), decrease in adenosine triphosphate (ATP), deformation of mitochondria, up‐regulation of deoxyribonucleic acid (DNA) damage and increase in apoptosis. Blockage of MCU by RR prevented Ca2+ and iron accumulation, abated the level of oxidative stress, improved the energy supply, stabilized mitochondria, reduced DNA damage and decreased apoptosis both in vivo and in vitro. Interestingly, Sper did not increase cellular Ca2+ and iron concentrations, but suppressed the Ca2+ and iron accumulation to benefit the mice in vivo. However, Sper had no significant impact on TBI in vitro. Taken together, our data demonstrated for the first time that blockage of MCU‐mediated Ca2+ and iron accumulation was essential for TBI. These findings indicated that MCU could be a novel therapeutic target for treating TBI.
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Affiliation(s)
- Li Zhang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Handong Wang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Xiaoming Zhou
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Lei Mao
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Ke Ding
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Zhigang Hu
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China
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12
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Englinger B, Pirker C, Heffeter P, Terenzi A, Kowol CR, Keppler BK, Berger W. Metal Drugs and the Anticancer Immune Response. Chem Rev 2018; 119:1519-1624. [DOI: 10.1021/acs.chemrev.8b00396] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Bernhard Englinger
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Christine Pirker
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Petra Heffeter
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
- Research Cluster “Translational Cancer Therapy Research”, University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Alessio Terenzi
- Research Cluster “Translational Cancer Therapy Research”, University of Vienna and Medical University of Vienna, Vienna, Austria
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 42, A-1090 Vienna, Austria
| | - Christian R. Kowol
- Research Cluster “Translational Cancer Therapy Research”, University of Vienna and Medical University of Vienna, Vienna, Austria
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 42, A-1090 Vienna, Austria
| | - Bernhard K. Keppler
- Research Cluster “Translational Cancer Therapy Research”, University of Vienna and Medical University of Vienna, Vienna, Austria
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 42, A-1090 Vienna, Austria
| | - Walter Berger
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
- Research Cluster “Translational Cancer Therapy Research”, University of Vienna and Medical University of Vienna, Vienna, Austria
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De Vriese K, Costa A, Beeckman T, Vanneste S. Pharmacological Strategies for Manipulating Plant Ca 2+ Signalling. Int J Mol Sci 2018; 19:E1506. [PMID: 29783646 PMCID: PMC5983822 DOI: 10.3390/ijms19051506] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/10/2018] [Accepted: 05/12/2018] [Indexed: 11/20/2022] Open
Abstract
Calcium is one of the most pleiotropic second messengers in all living organisms. However, signalling specificity is encoded via spatio-temporally regulated signatures that act with surgical precision to elicit highly specific cellular responses. How this is brought about remains a big challenge in the plant field, in part due to a lack of specific tools to manipulate/interrogate the plant Ca2+ toolkit. In many cases, researchers resort to tools that were optimized in animal cells. However, the obviously large evolutionary distance between plants and animals implies that there is a good chance observed effects may not be specific to the intended plant target. Here, we provide an overview of pharmacological strategies that are commonly used to activate or inhibit plant Ca2+ signalling. We focus on highlighting modes of action where possible, and warn for potential pitfalls. Together, this review aims at guiding plant researchers through the Ca2+ pharmacology swamp.
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Affiliation(s)
- Kjell De Vriese
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Ghent, Belgium.
- VIB Center for Plant Systems Biology, VIB, Technologiepark 927, 9052 Ghent, Belgium.
| | - Alex Costa
- Department of Biosciences, University of Milan, 20133 Milan, Italy.
- Instititute of Biophysics, Consiglio Nazionale delle Ricerche, 20133 Milan, Italy.
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Ghent, Belgium.
- VIB Center for Plant Systems Biology, VIB, Technologiepark 927, 9052 Ghent, Belgium.
| | - Steffen Vanneste
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Ghent, Belgium.
- VIB Center for Plant Systems Biology, VIB, Technologiepark 927, 9052 Ghent, Belgium.
- Lab of Plant Growth Analysis, Ghent University Global Campus, Songdomunhwa-Ro, 119, Yeonsu-gu, Incheon 21985, Korea.
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Lindström JB, Pierce NT, Latz MI. Role of TRP Channels in Dinoflagellate Mechanotransduction. THE BIOLOGICAL BULLETIN 2017; 233:151-167. [PMID: 29373067 DOI: 10.1086/695421] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Transient receptor potential (TRP) ion channels are common components of mechanosensing pathways, mainly described in mammals and other multicellular organisms. To gain insight into the evolutionary origins of eukaryotic mechanosensory proteins, we investigated the involvement of TRP channels in mechanosensing in a unicellular eukaryotic protist, the dinoflagellate Lingulodinium polyedra. BLASTP analysis of the protein sequences predicted from the L. polyedra transcriptome revealed six sequences with high similarity to human TRPM2, TRPM8, TRPML2, TRPP1, and TRPP2; and characteristic TRP domains were identified in all sequences. In a phylogenetic tree including all mammalian TRP subfamilies and TRP channel sequences from unicellular and multicellular organisms, the L. polyedra sequences grouped with the TRPM, TPPML, and TRPP clades. In pharmacological experiments, we used the intrinsic bioluminescence of L. polyedra as a reporter of mechanoresponsivity. Capsaicin and RN1734, agonists of mammalian TRPV, and arachidonic acid, an agonist of mammalian TRPV, TRPA, TRPM, and Drosophila TRP, all stimulated bioluminescence in L. polyedra. Mechanical stimulation of bioluminescence, but not capsaicin-stimulated bioluminescence, was inhibited by gadolinium (Gd3+), a general inhibitor of mechanosensitive ion channels, and the phospholipase C (PLC) inhibitor U73122. These pharmacological results are consistent with the involvement of TRP-like channels in mechanosensing by L. polyedra. The TRP channels do not appear to be mechanoreceptors but rather are components of the mechanotransduction signaling pathway and may be activated via a PLC-dependent mechanism. The presence and function of TRP channels in a dinoflagellate emphasize the evolutionary conservation of both the channel structures and their functions.
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Key Words
- AA, amino acids
- AMTB hydrochloride, N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide hydrochloride
- Ce, Caenorhabditis elegans
- Cr, Chlamydomonas reinhardtii
- DMSO, dimethyl sulfoxide
- Dm, Drosophila melanogaster
- Dr, Danio rerio
- FSW, filtered seawater
- Gd3+, gadolinium
- GsMTx4, Grammostola spatulata mechanotoxin 4
- HC067047, 2-Methyl-1-[3-(4-morpholinyl)propyl]-5-phenyl-N-[3-(trifluoromethyl)phenyl]-1H-pyrrole-3-carboxamide
- HMM, Hidden Markov Model
- Hs, Homo sapiens
- Lp, Lingulodinium polyedra
- ML204, 4-Methyl-2-(1-piperidinyl)-quinoline
- Mb, Monosiga brevicollis
- ORF, open reading frame
- PIP2, Phosphatidylinositol 4,5-bisphosphate
- PLC, phospholipase C
- Pt, Paramecium tetraurelia
- RHC80267, O,O′-[1,6-Hexanediylbis(iminocarbonyl)]dioxime cyclohexanone
- RN1734, 2,4-Dichloro-N-isopropyl-N-(2-isopropylaminoethyl)benzenesulfonamide
- RN1747, 1-(4-Chloro-2-nitrophenyl)sulfonyl-4-benzylpiperazine
- TMHMM, transmembrane helix prediction
- TRP, transient receptor potential channel
- U73122, 1-[6-[((17β)-3-Methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dione
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Cheng H, Li J, James AF, Inada S, Choisy SCM, Orchard CH, Zhang H, Boyett MR, Hancox JC. Characterization and influence of cardiac background sodium current in the atrioventricular node. J Mol Cell Cardiol 2016; 97:114-24. [PMID: 27132017 PMCID: PMC5007024 DOI: 10.1016/j.yjmcc.2016.04.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 04/01/2016] [Accepted: 04/25/2016] [Indexed: 01/19/2023]
Abstract
Background inward sodium current (IB,Na) that influences cardiac pacemaking has been comparatively under-investigated. The aim of this study was to determine for the first time the properties and role of IB,Na in cells from the heart's secondary pacemaker, the atrioventricular node (AVN). Myocytes were isolated from the AVN of adult male rabbits and mice using mechanical and enzymatic dispersion. Background current was measured using whole-cell patch clamp and monovalent ion substitution with major voltage- and time-dependent conductances inhibited. In the absence of a selective pharmacological inhibitor of IB,Na, computer modelling was used to assess the physiological contribution of IB,Na. Net background current during voltage ramps was linear, reversing close to 0mV. Switching between Tris- and Na(+)-containing extracellular solution in rabbit and mouse AVN cells revealed an inward IB,Na, with an increase in slope conductance in rabbit cells at -50mV from 0.54±0.03 to 0.91±0.05nS (mean±SEM; n=61 cells). IB,Na magnitude varied in proportion to [Na(+)]o. Other monovalent cations could substitute for Na(+) (Rb(+)>K(+)>Cs(+)>Na(+)>Li(+)). The single-channel conductance with Na(+) as charge carrier estimated from noise-analysis was 3.2±1.2pS (n=6). Ni(2+) (10mM), Gd(3+) (100μM), ruthenium red (100μM), or amiloride (1mM) produced modest reductions in IB,Na. Flufenamic acid was without significant effect, whilst La(3+) (100μM) or extracellular acidosis (pH6.3) inhibited the current by >60%. Under the conditions of our AVN cell simulations, removal of IB,Na arrested spontaneous activity and, in a simulated 1D-strand, reduced conduction velocity by ~20%. IB,Na is carried by distinct low conductance monovalent non-selective cation channels and can influence AVN spontaneous activity and conduction.
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Affiliation(s)
- Hongwei Cheng
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Jue Li
- Institute of Cardiovascular Sciences, University of Manchester, Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, UK
| | - Andrew F James
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Shin Inada
- Institute of Cardiovascular Sciences, University of Manchester, Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, UK
| | - Stéphanie C M Choisy
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Clive H Orchard
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Henggui Zhang
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Mark R Boyett
- Institute of Cardiovascular Sciences, University of Manchester, Core Technology Facility, 46 Grafton Street, Manchester M13 9NT, UK
| | - Jules C Hancox
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK.
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16
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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] [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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17
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Yin J, Hoffmann J, Kaestle SM, Neye N, Wang L, Baeurle J, Liedtke W, Wu S, Kuppe H, Pries AR, Kuebler WM. Negative-feedback loop attenuates hydrostatic lung edema via a cGMP-dependent regulation of transient receptor potential vanilloid 4. Circ Res 2008; 102:966-74. [PMID: 18323527 DOI: 10.1161/circresaha.107.168724] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the formation of hydrostatic lung edema is generally attributed to imbalanced Starling forces, recent data show that lung endothelial cells respond to increased vascular pressure and may thus regulate vascular permeability and edema formation. In combining real-time optical imaging of the endothelial Ca(2+) concentration ([Ca(2+)](i)) and NO production with filtration coefficient (K(f)) measurements in the isolated perfused lung, we identified a series of endothelial responses that constitute a negative-feedback loop to protect the microvascular barrier. Elevation of lung microvascular pressure was shown to increase endothelial [Ca(2+)](i) via activation of transient receptor potential vanilloid 4 (TRPV4) channels. The endothelial [Ca(2+)](i) transient increased K(f) via activation of myosin light-chain kinase and simultaneously stimulated NO synthesis. In TRPV4 deficient mice, pressure-induced increases in endothelial [Ca(2+)](i), NO synthesis, and lung wet/dry weight ratio were largely blocked. Endothelial NO formation limited the permeability increase by a cGMP-dependent attenuation of the pressure-induced [Ca(2+)](i) response. Inactivation of TRPV4 channels by cGMP was confirmed by whole-cell patch-clamp of pulmonary microvascular endothelial cells and intravital imaging of endothelial [Ca(2+)](i). Hence, pressure-induced endothelial Ca(2+) influx via TRPV4 channels increases lung vascular permeability yet concomitantly activates an NO-mediated negative-feedback loop that protects the vascular barrier by a cGMP-dependent attenuation of the endothelial [Ca(2+)](i) response. The identification of this novel regulatory pathway gives rise to new treatment strategies, as demonstrated in vivo in rats with acute myocardial infarction in which inhibition of cGMP degradation by the phosphodiesterase 5 inhibitor sildenafil reduced hydrostatic lung edema.
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Affiliation(s)
- Jun Yin
- Institute of Physiology, Charité-Universitaetsmedizin Berlin, Campus Benjamin Franklin, Arnimallee 22, 14195 Berlin, Germany
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18
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Wang GJ, Thayer SA. NMDA-induced calcium loads recycle across the mitochondrial inner membrane of hippocampal neurons in culture. J Neurophysiol 2002; 87:740-9. [PMID: 11826043 DOI: 10.1152/jn.00345.2001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mitochondria sequester N-methyl-D-aspartate (NMDA)-induced Ca(2+) loads and regulate the shape of intracellular Ca(2+) concentration ([Ca(2+)](i)) responses in neurons. When isolated mitochondria are exposed to high [Ca(2+)](,) Ca(2+) enters the matrix via the uniporter and returns to the cytosol by Na(+)/Ca(2+) exchange. Released Ca(2+) may re-enter the mitochondrion recycling across the inner membrane dissipating respiratory energy. Ca(2+) recycling, the continuous uptake and release of Ca(2+) by mitochondria, has not been described in intact neurons. Here we used single-cell microfluorimetry to measure [Ca(2+)](i) and mitochondrially targeted aequorin to measure matrix Ca(2+) concentration ([Ca(2+)](mt)) to determine whether Ca(2+) recycles across the mitochondrial inner membrane in intact neurons following treatment with NMDA. We used ruthenium red and CGP 37157 to block uptake via the uniporter and release via Na(+)/Ca(2+) exchange, respectively. As predicted by the Ca(2+) recycling hypothesis, blocking the uniporter immediately following challenge with 200 microM NMDA produced a rapid and transient increase in cytosolic Ca(2+) without a corresponding increase in matrix Ca(2+). Blocking mitochondrial Ca(2+) release produced the opposite effect, depressing cytosolic Ca(2+) levels and prolonging the time for matrix Ca(2+) levels to recover. The Ca(2+) recycling hypothesis uniquely predicts these reciprocal changes in the Ca(2+) levels between the two compartments. Ca(2+) recycling was not detected following treatment with 20 microM NMDA. Thus Ca(2+) recycling across the inner membrane was more pronounced following treatment with a high relative to a low concentration of NMDA, consistent with a role in Ca(2+)-dependent neurotoxicity.
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Affiliation(s)
- Guang Jian Wang
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455-0217, USA
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19
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Linn CL, Gafka AC. Modulation of a voltage-gated calcium channel linked to activation of glutamate receptors and calcium-induced calcium release in the catfish retina. J Physiol 2001; 535:47-63. [PMID: 11507157 PMCID: PMC2278768 DOI: 10.1111/j.1469-7793.2001.00047.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
1. Catfish (Ictalurus punctatus) retinal cone horizontal cells contain an L-type calcium current that has been proposed to be involved in visual processing. Here we report on the modulation of this current by activation of glutamate receptors and calcium-induced calcium release (CICR) from intracellular calcium stores. 2. Fluorescence data obtained from isolated horizontal cells loaded with indo-1 provided evidence of calcium release from an intracellular calcium store sensitive to caffeine, calcium and ryanodine. In the presence of caffeine, ryanodine-sensitive stores released calcium in a transient manner. Release of calcium was blocked when cells were preincubated in BAPTA, in the presence of ruthenium red, or in low concentrations of ryanodine. 3. The release of calcium from ryanodine-sensitive stores directly corresponded with a decrease of the voltage-gated L-type calcium current amplitude. Caffeine-induced modulation of the calcium current was reduced in the presence of ruthenium red. 4. Activation of ionotropic kainate receptors on catfish cone horizontal cells triggered CICR from ryanodine-sensitive stores and mimicked inhibition of the voltage-gated calcium current. Kainate-induced inhibition of the calcium current was diminished when intracellular calcium stores were inhibited with ruthenium red or depleted with ryanodine, or when calmodulin antagonists or CaM kinase II inhibitors were present. 5. These results provide evidence that activation of an ionotropic glutamate receptor on catfish cone horizontal cells is linked to calcium release from ryanodine-sensitive intracellular calcium stores and modulation of the L-type calcium current activity. Inhibition of this calcium current directly or indirectly involves calmodulin and CaM kinase II and represents a possible mechanism used by horizontal cells to affect response properties of these cells.
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Affiliation(s)
- C L Linn
- Western Michigan University, Department of Biological Sciences, 1903 W. Michigan Avenue, Kalamazoo, MI 49008, USA.
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20
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Abstract
Mitochondria play a central role in the survival and death of neurons. The detailed bioenergetic mechanisms by which isolated mitochondria generate ATP, sequester Ca(2+), generate reactive oxygen species, and undergo Ca(2+)-dependent permeabilization of their inner membrane are currently being applied to the function of mitochondria in situ within neurons under physiological and pathophysiological conditions. Here we review the functional bioenergetics of isolated mitochondria, with emphasis on the chemiosmotic proton circuit and the application (and occasional misapplication) of these principles to intact neurons. Mitochondria play an integral role in both necrotic and apoptotic neuronal cell death, and the bioenergetic principles underlying current studies are reviewed.
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Affiliation(s)
- D G Nicholls
- Department of Pharmacology, University of Dundee, Dundee, Scotland.
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21
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Pottosin II, Dobrovinskaya OR, Muñiz J. Cooperative block of the plant endomembrane ion channel by ruthenium red. Biophys J 1999; 77:1973-9. [PMID: 10512817 PMCID: PMC1300478 DOI: 10.1016/s0006-3495(99)77038-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Effects of ruthenium red (RR) on the slow Ca(2+)-activated Ca(2+)-permeable vacuolar channel have been studied by patch-clamp technique. Applied to the cytosolic side of isolated membrane patches, RR at concentrations of 0.1-5 microM produced two distinct effects on single channel kinetics, long lasting closures and a flickering block of the open state. The first effect was largely irreversible, whereas the second one could be washed out. The extent of flickering block steeply increased (zdelta = approximately 1.35) with the increase of cytosol-positive voltage, dragging RR into the channel pore. At least two RR ions are involved in the block according to Hill coefficient n = approximately 1.30 for the dose response curves. The on-rate rate of the drug binding linearly depended on the RR concentration, implying that one RR ion already plugged the pore. The blocked state was further stabilized by binding of the second RR. This stabilization was in excess of that predicted by independent binding as the dependence of unblocking rate on RR concentration revealed. A cooperative model was therefore employed to describe the kinetic behavior of RR binding. At zero voltage the half-blocking RR concentration of 36 microM and the bimolecular on-rate constant of 1.8 x 10(8) M(-1) s(-1) were estimated.
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Affiliation(s)
- I I Pottosin
- Centro Universitario de Investigaciones Biomedicas, Universidad de Colima, 28047 Colima, México.
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