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Csordás G, Weaver D, Várnai P, Hajnóczky G. Supralinear Dependence of the IP 3 Receptor-to-Mitochondria Local Ca 2+ Transfer on the Endoplasmic Reticulum Ca 2+ Loading. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2024; 7:25152564241229273. [PMID: 38362008 PMCID: PMC10868505 DOI: 10.1177/25152564241229273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 12/31/2023] [Accepted: 01/12/2024] [Indexed: 02/17/2024]
Abstract
Calcium signal propagation from endoplasmic reticulum (ER) to mitochondria regulates a multitude of mitochondrial and cell functions, including oxidative ATP production and cell fate decisions. Ca2+ transfer is optimal at the ER-mitochondrial contacts, where inositol 1,4,5-trisphosphate (IP3) receptors (IP3R) can locally expose the mitochondrial Ca2+ uniporter (mtCU) to high [Ca2+] nanodomains. The Ca2+ loading state of the ER (Ca2 + ER) can vary broadly in physiological and pathological scenarios, however, the correlation between Ca2 + ER and the local Ca2+ transfer is unclear. Here, we studied IP3-induced Ca2+ transfer to mitochondria at different Ca2 + ER in intact and permeabilized RBL-2H3 cells via fluorescence measurements of cytoplasmic [Ca2+] ([Ca2+]c) and mitochondrial matrix [Ca2+] ([Ca2+]m). Preincubation of intact cells in high versus low extracellular [Ca2+] caused disproportionally greater increase in [Ca2+]m than [Ca2+]c responses to IP3-mobilizing agonist. Increasing Ca2 + ER by small Ca2+ boluses in suspensions of permeabilized cells supralinearly enhanced the mitochondrial Ca2+ uptake from IP3-induced Ca2+ release. The IP3-induced local [Ca2+] spikes exposing the mitochondrial surface measured using a genetically targeted sensor appeared to linearly correlate with Ca2 + ER, indicating that amplification happened in the mitochondria. Indeed, overexpression of an EF-hand deficient mutant of the mtCU gatekeeper MICU1 reduced the cooperativity of mitochondrial Ca2+ uptake. Interestingly, the IP3-induced [Ca2+]m signal plateaued at high Ca2 + ER, indicating activation of a matrix Ca2+ binding/chelating species. Mitochondria thus seem to maintain a "working [Ca2+]m range" via a low-affinity and high-capacity buffer species, and the ER loading steeply enhances the IP3R-linked [Ca2+]m signals in this working range.
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Affiliation(s)
- György Csordás
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - David Weaver
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Péter Várnai
- Department of Physiology, Semmelweis Medical University, Budapest, Hungary
| | - György Hajnóczky
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
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2
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de los Ríos C, Viejo L, Carretero VJ, Juárez NH, Cruz-Martins N, Hernández-Guijo JM. Promising Molecular Targets in Pharmacological Therapy for Neuronal Damage in Brain Injury. Antioxidants (Basel) 2023; 12:118. [PMID: 36670980 PMCID: PMC9854812 DOI: 10.3390/antiox12010118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/19/2022] [Accepted: 12/27/2022] [Indexed: 01/05/2023] Open
Abstract
The complex etiopathogenesis of brain injury associated with neurodegeneration has sparked a lot of studies in the last century. These clinical situations are incurable, and the currently available therapies merely act on symptoms or slow down the course of the diseases. Effective methods are being sought with an intent to modify the disease, directly acting on the properly studied targets, as well as to contribute to the development of effective therapeutic strategies, opening the possibility of refocusing on drug development for disease management. In this sense, this review discusses the available evidence for mitochondrial dysfunction induced by Ca2+ miscommunication in neurons, as well as how targeting phosphorylation events may be used to modulate protein phosphatase 2A (PP2A) activity in the treatment of neuronal damage. Ca2+ tends to be the catalyst for mitochondrial dysfunction, contributing to the synaptic deficiency seen in brain injury. Additionally, emerging data have shown that PP2A-activating drugs (PADs) suppress inflammatory responses by inhibiting different signaling pathways, indicating that PADs may be beneficial for the management of neuronal damage. In addition, a few bioactive compounds have also triggered the activation of PP2A-targeted drugs for this treatment, and clinical studies will help in the authentication of these compounds. If the safety profiles of PADs are proven to be satisfactory, there is a case to be made for starting clinical studies in the setting of neurological diseases as quickly as possible.
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Affiliation(s)
- Cristóbal de los Ríos
- Department of Pharmacology and Therapeutic and Teófilo Hernando Institute, Faculty of Medicine, University Autónoma de Madrid, C/. Arzobispo Morcillo 4, 28029 Madrid, Spain
- Departamento de Ciencias Básicas de la Salud, University Rey Juan Carlos, Avda. Atenas s/n, 28922 Alcorcón, Spain
| | - Lucía Viejo
- Department of Pharmacology and Therapeutic and Teófilo Hernando Institute, Faculty of Medicine, University Autónoma de Madrid, C/. Arzobispo Morcillo 4, 28029 Madrid, Spain
| | - Victoria Jiménez Carretero
- Department of Pharmacology and Therapeutic and Teófilo Hernando Institute, Faculty of Medicine, University Autónoma de Madrid, C/. Arzobispo Morcillo 4, 28029 Madrid, Spain
| | - Natalia Hernández Juárez
- Department of Pharmacology and Therapeutic and Teófilo Hernando Institute, Faculty of Medicine, University Autónoma de Madrid, C/. Arzobispo Morcillo 4, 28029 Madrid, Spain
| | - Natália Cruz-Martins
- Faculty of Medicine, Institute for Research and Innovation in Health (i3S), University of Porto, 4200-319 Porto, Portugal
- Institute for Research and Advanced Training in Health Sciences and Technologies, Rua Central de Gandra, 1317, 4585-116 Gandra, Portugal
| | - Jesús M. Hernández-Guijo
- Department of Pharmacology and Therapeutic and Teófilo Hernando Institute, Faculty of Medicine, University Autónoma de Madrid, C/. Arzobispo Morcillo 4, 28029 Madrid, Spain
- Ramón y Cajal Institute for Health Research, IRYCIS, Hospital Ramón y Cajal, Ctra. de Colmenar Viejo, Km. 9,100, 28029 Madrid, Spain
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3
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Wettmarshausen J, Goh V, Huang KT, Arduino DM, Tripathi U, Leimpek A, Cheng Y, Pittis AA, Gabaldón T, Mokranjac D, Hajnóczky G, Perocchi F. MICU1 Confers Protection from MCU-Dependent Manganese Toxicity. Cell Rep 2019; 25:1425-1435.e7. [PMID: 30403999 DOI: 10.1016/j.celrep.2018.10.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/09/2018] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
Abstract
The mitochondrial calcium uniporter is a highly selective ion channel composed of species- and tissue-specific subunits. However, the functional role of each component still remains unclear. Here, we establish a synthetic biology approach to dissect the interdependence between the pore-forming subunit MCU and the calcium-sensing regulator MICU1. Correlated evolutionary patterns across 247 eukaryotes indicate that their co-occurrence may have conferred a positive fitness advantage. We find that, while the heterologous reconstitution of MCU and EMRE in vivo in yeast enhances manganese stress, this is prevented by co-expression of MICU1. Accordingly, MICU1 deletion sensitizes human cells to manganese-dependent cell death by disinhibiting MCU-mediated manganese uptake. As a result, manganese overload increases oxidative stress, which can be effectively prevented by NAC treatment. Our study identifies a critical contribution of MICU1 to the uniporter selectivity, with important implications for patients with MICU1 deficiency, as well as neurological disorders arising upon chronic manganese exposure.
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Affiliation(s)
- Jennifer Wettmarshausen
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Valerie Goh
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Kai-Ting Huang
- Department of Pathology, Anatomy, and Cell Biology, MitoCare Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Daniela M Arduino
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Utkarsh Tripathi
- Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Anja Leimpek
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Yiming Cheng
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Alexandros A Pittis
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain; Departament of Ciències Experimentals I de La Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain; Departament of Ciències Experimentals I de La Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Dejana Mokranjac
- Biomedical Center Munich - Physiological Chemistry, Ludwig-Maximilians Universität München, 82152 Martinsried, Germany
| | - György Hajnóczky
- Department of Pathology, Anatomy, and Cell Biology, MitoCare Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Fabiana Perocchi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany; Munich Cluster for Systems Neurology, 81377 Munich, Germany.
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4
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Modeling the role of endoplasmic reticulum-mitochondria microdomains in calcium dynamics. Sci Rep 2019; 9:17072. [PMID: 31745211 PMCID: PMC6864103 DOI: 10.1038/s41598-019-53440-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/31/2019] [Indexed: 12/12/2022] Open
Abstract
Upon inositol trisphosphate (IP3) stimulation of non-excitable cells, including vascular endothelial cells, calcium (Ca2+) shuttling between the endoplasmic reticulum (ER) and mitochondria, facilitated by complexes called Mitochondria-Associated ER Membranes (MAMs), is known to play an important role in the occurrence of cytosolic Ca2+ concentration ([Ca2+]Cyt) oscillations. A mathematical compartmental closed-cell model of Ca2+ dynamics was developed that accounts for ER-mitochondria Ca2+ microdomains as the µd compartment (besides the cytosol, ER and mitochondria), Ca2+ influx to/efflux from each compartment and Ca2+ buffering. Varying the distribution of functional receptors in MAMs vs. the rest of ER/mitochondrial membranes, a parameter called the channel connectivity coefficient (to the µd), allowed for generation of [Ca2+]Cytoscillations driven by distinct mechanisms at various levels of IP3 stimulation. Oscillations could be initiated by the transient opening of IP3 receptors facing either the cytosol or the µd, and subsequent refilling of the respective compartment by Ca2+ efflux from the ER and/or the mitochondria. Only under conditions where the µd became the oscillation-driving compartment, silencing the Mitochondrial Ca2+ Uniporter led to oscillation inhibition. Thus, the model predicts that alternative mechanisms can yield [Ca2+]Cyt oscillations in non-excitable cells, and, under certain conditions, the ER-mitochondria µd can play a regulatory role.
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5
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Slepchenko KG, Lu Q, Li YV. Cross talk between increased intracellular zinc (Zn 2+) and accumulation of reactive oxygen species in chemical ischemia. Am J Physiol Cell Physiol 2017; 313:C448-C459. [PMID: 28747335 DOI: 10.1152/ajpcell.00048.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/21/2017] [Accepted: 07/21/2017] [Indexed: 12/16/2022]
Abstract
Both zinc (Zn2+) and reactive oxygen species (ROS) have been shown to accumulate during hypoxic-ischemic stress and play important roles in pathological processes. To understand the cross talk between the two of them, here we studied Zn2+ and ROS accumulation by employing fluorescent probes in HeLa cells to further the understanding of the cause and effect relationship of these two important cellular signaling systems during chemical-ischemia, stimulated by oxygen and glucose deprivation (OGD). We observed two Zn2+ rises that were divided into four phases in the course of 30 min of OGD. The first Zn2+ rise was a transient, which was followed by a latent phase during which Zn2+ levels recovered; however, levels remained above a basal level in most cells. The final phase was the second Zn2+ rise, which reached a sustained plateau called Zn2+ overload. Zn2+ rises were not observed when Zn2+ was removed by TPEN (a Zn2+ chelator) or thapsigargin (depleting Zn2+ from intracellular stores) treatment, indicating that Zn2+ was from intracellular storage. Damaging mitochondria with FCCP significantly reduced the second Zn2+ rise, indicating that the mitochondrial Zn2+ accumulation contributes to Zn2+ overload. We also detected two OGD-induced ROS rises. Two Zn2+ rises preceded two ROS rises. Removal of Zn2+ reduced or delayed OGD- and FCCP-induced ROS generation, indicating that Zn2+ contributes to mitochondrial ROS generation. There was a Zn2+-induced increase in the functional component of NADPH oxidase, p47phox, thus suggesting that NADPH oxidase may mediate Zn2+-induced ROS accumulation. We suggest a new mechanism of cross talk between Zn2+ and mitochondrial ROS through positive feedback processes that eventually causes excessive free Zn2+ and ROS accumulations during the course of ischemic stress.
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Affiliation(s)
- Kira G Slepchenko
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio; and
| | - Qiping Lu
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, Ohio
| | - Yang V Li
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio; and
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6
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Thom SR, Bhopale VM, Hu J, Yang M. Increased carbon dioxide levels stimulate neutrophils to produce microparticles and activate the nucleotide-binding domain-like receptor 3 inflammasome. Free Radic Biol Med 2017; 106:406-416. [PMID: 28288918 DOI: 10.1016/j.freeradbiomed.2017.03.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/22/2017] [Accepted: 03/08/2017] [Indexed: 11/22/2022]
Abstract
We hypothesized that elevations of carbon dioxide (CO2) commonly found in modern buildings will stimulate leukocytes to produce microparticles (MPs) and activate the nucleotide-binding domain-like receptor 3 (NLRP3) inflammasome due to mitochondrial oxidative stress. Human and murine neutrophils generate MPs with high interleukin-1β (IL-1β) content when incubated ex vivo in buffer equilibrated with 0.1-0.4% additional CO2. Enhanced MPs production requires mitochondrial reactive oxygen species production, which is mediated by activities of pyruvate carboxylase and phosphoenolpyruvate carboxykinase. Subsequent events leading to MPs generation include perturbation of inositol 1,3,5-triphosphate receptors, a transient elevation of intracellular calcium, activation of protein kinase C and NADPH oxidase (Nox). Concomitant activation of type-2 nitric oxide synthase yields secondary oxidants resulting in actin S-nitrosylation and enhanced filamentous actin turnover. Numerous proteins are linked to short filamentous actin including vasodilator-stimulated phosphoprotein, focal adhesion kinase, the membrane phospholipid translocation enzymes flippase and floppase, and the critical inflammasome protein ASC (Apoptosis-associated Speck protein with CARD domain). Elevations of CO2 cause oligomerization of the inflammasome components ASC, NLRP3, caspase 1, thioredoxin interacting protein, and calreticulin - a protein from endoplasmic reticulum, leading to IL-1β synthesis. An increased production rate of MPs containing elevated amounts of IL-1β persists for hours after short-term exposures to elevated CO2.
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Affiliation(s)
- Stephen R Thom
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Veena M Bhopale
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - JingPing Hu
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Ming Yang
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States
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7
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Mishra J, Jhun BS, Hurst S, O-Uchi J, Csordás G, Sheu SS. The Mitochondrial Ca 2+ Uniporter: Structure, Function, and Pharmacology. Handb Exp Pharmacol 2017; 240:129-156. [PMID: 28194521 PMCID: PMC5554456 DOI: 10.1007/164_2017_1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Mitochondrial Ca2+ uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca2+ uptake and our current understanding of mitochondrial Ca2+ homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca2+ uniporter complex.
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Affiliation(s)
- Jyotsna Mishra
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Suite 543D, Philadelphia, PA, 19107, USA
| | - Bong Sook Jhun
- Cardiovascular Research Center, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | - Stephen Hurst
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Suite 543D, Philadelphia, PA, 19107, USA
| | - Jin O-Uchi
- Cardiovascular Research Center, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA.
| | - György Csordás
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Suite 543D, Philadelphia, PA, 19107, USA.
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8
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Mitochondrial Mg(2+) homeostasis decides cellular energy metabolism and vulnerability to stress. Sci Rep 2016; 6:30027. [PMID: 27458051 PMCID: PMC4960558 DOI: 10.1038/srep30027] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 06/28/2016] [Indexed: 01/23/2023] Open
Abstract
Cellular energy production processes are composed of many Mg2+ dependent enzymatic reactions. In fact, dysregulation of Mg2+ homeostasis is involved in various cellular malfunctions and diseases. Recently, mitochondria, energy-producing organelles, have been known as major intracellular Mg2+ stores. Several biological stimuli alter mitochondrial Mg2+ concentration by intracellular redistribution. However, in living cells, whether mitochondrial Mg2+ alteration affect cellular energy metabolism remains unclear. Mg2+ transporter of mitochondrial inner membrane MRS2 is an essential component of mitochondrial Mg2+ uptake system. Here, we comprehensively analyzed intracellular Mg2+ levels and energy metabolism in Mrs2 knockdown (KD) cells using fluorescence imaging and metabolome analysis. Dysregulation of mitochondrial Mg2+ homeostasis disrupted ATP production via shift of mitochondrial energy metabolism and morphology. Moreover, Mrs2 KD sensitized cellular tolerance against cellular stress. These results indicate regulation of mitochondrial Mg2+via MRS2 critically decides cellular energy status and cell vulnerability via regulation of mitochondrial Mg2+ level in response to physiological stimuli.
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9
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Sui B, Liu X, Wang M, Belfield KD. A Highly Selective Fluorescence Turn-On Sensor for Extracellular Calcium Ion Detection. Chemistry 2016; 22:10351-4. [PMID: 27247191 DOI: 10.1002/chem.201602162] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Indexed: 11/08/2022]
Abstract
A highly water-soluble, fluorescence turn-on sensor for Ca(2+) is reported. The sensor affords high selectivity in sensing Ca(2+) over other biologically important metal cations. The dissociation constant of the sensor in binding Ca(2+) is 0.92 mm. Fluorescence microscopy experiments demonstrate that the sensor is cell-impermeable and capable of detecting extracellular Ca(2+) .
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Affiliation(s)
- Binglin Sui
- College of Science and Liberal Arts, New Jersey Institute of Technology, Newark, New Jersey, 07102, United States
| | - Xinglei Liu
- College of Science and Liberal Arts, New Jersey Institute of Technology, Newark, New Jersey, 07102, United States
| | - Mengyuan Wang
- Department of Chemistry, University of Central Florida, Orlando, Florida, 32816, United States
| | - Kevin D Belfield
- College of Science and Liberal Arts, New Jersey Institute of Technology, Newark, New Jersey, 07102, United States.
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10
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Suzuki Y, Yokoyama K. Development of Functional Fluorescent Molecular Probes for the Detection of Biological Substances. BIOSENSORS 2015; 5:337-63. [PMID: 26095660 PMCID: PMC4493553 DOI: 10.3390/bios5020337] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 01/27/2023]
Abstract
This review is confined to sensors that use fluorescence to transmit biochemical information. Fluorescence is, by far, the most frequently exploited phenomenon for chemical sensors and biosensors. Parameters that define the application of such sensors include intensity, decay time, anisotropy, quenching efficiency, and luminescence energy transfer. To achieve selective (bio)molecular recognition based on these fluorescence phenomena, various fluorescent elements such as small organic molecules, enzymes, antibodies, and oligonucleotides have been designed and synthesized over the past decades. This review describes the immense variety of fluorescent probes that have been designed for the recognitions of ions, small and large molecules, and their biological applications in terms of intracellular fluorescent imaging techniques.
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Affiliation(s)
- Yoshio Suzuki
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba 305-8566, Japan.
| | - Kenji Yokoyama
- School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan.
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11
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In vivo tissue-wide synchronization of mitochondrial metabolic oscillations. Cell Rep 2014; 9:514-21. [PMID: 25373899 DOI: 10.1016/j.celrep.2014.09.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/09/2014] [Accepted: 09/11/2014] [Indexed: 11/20/2022] Open
Abstract
Little is known about the spatiotemporal coordination of mitochondrial metabolism in multicellular organisms in situ. Using intravital microscopy in live animals, we report that mitochondrial metabolism undergoes rapid and periodic oscillations under basal conditions. Notably, mitochondria in vivo behave as a network of functionally coupled oscillators, which maintain a high level of coordination throughout the tissue via the activity of gap junctions. These findings reveal a unique aspect of the relationship between tissue architecture and self-organization of mitochondrial metabolism in vivo.
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12
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Plasma membrane Ca2+-ATPase isoforms composition regulates cellular pH homeostasis in differentiating PC12 cells in a manner dependent on cytosolic Ca2+ elevations. PLoS One 2014; 9:e102352. [PMID: 25014339 PMCID: PMC4094512 DOI: 10.1371/journal.pone.0102352] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/17/2014] [Indexed: 12/14/2022] Open
Abstract
Plasma membrane Ca2+-ATPase (PMCA) by extruding Ca2+ outside the cell, actively participates in the regulation of intracellular Ca2+ concentration. Acting as Ca2+/H+ counter-transporter, PMCA transports large quantities of protons which may affect organellar pH homeostasis. PMCA exists in four isoforms (PMCA1-4) but only PMCA2 and PMCA3, due to their unique localization and features, perform more specialized function. Using differentiated PC12 cells we assessed the role of PMCA2 and PMCA3 in the regulation of intracellular pH in steady-state conditions and during Ca2+ overload evoked by 59 mM KCl. We observed that manipulation in PMCA expression elevated pHmito and pHcyto but only in PMCA2-downregulated cells higher mitochondrial pH gradient (ΔpH) was found in steady-state conditions. Our data also demonstrated that PMCA2 or PMCA3 knock-down delayed Ca2+ clearance and partially attenuated cellular acidification during KCl-stimulated Ca2+ influx. Because SERCA and NCX modulated cellular pH response in neglectable manner, and all conditions used to inhibit PMCA prevented KCl-induced pH drop, we considered PMCA2 and PMCA3 as mainly responsible for transport of protons to intracellular milieu. In steady-state conditions, higher TMRE uptake in PMCA2-knockdown line was driven by plasma membrane potential (Ψp). Nonetheless, mitochondrial membrane potential (Ψm) in this line was dissipated during Ca2+ overload. Cyclosporin and bongkrekic acid prevented Ψm loss suggesting the involvement of Ca2+-driven opening of mitochondrial permeability transition pore as putative underlying mechanism. The findings presented here demonstrate a crucial role of PMCA2 and PMCA3 in regulation of cellular pH and indicate PMCA membrane composition important for preservation of electrochemical gradient.
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13
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Mitochondrial matrix Ca²⁺ accumulation regulates cytosolic NAD⁺/NADH metabolism, protein acetylation, and sirtuin expression. Mol Cell Biol 2014; 34:2890-902. [PMID: 24865966 DOI: 10.1128/mcb.00068-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial calcium uptake stimulates bioenergetics and drives energy production in metabolic tissue. It is unknown how a calcium-mediated acceleration in matrix bioenergetics would influence cellular metabolism in glycolytic cells that do not require mitochondria for ATP production. Using primary human endothelial cells (ECs), we discovered that repetitive cytosolic calcium signals (oscillations) chronically loaded into the mitochondrial matrix. Mitochondrial calcium loading in turn stimulated bioenergetics and a persistent elevation in NADH. Rather than serving as an impetus for mitochondrial ATP generation, matrix NADH rapidly transmitted to the cytosol to influence the activity and expression of cytosolic sirtuins, resulting in global changes in protein acetylation. In endothelial cells, the mitochondrion-driven reduction in both the cytosolic and mitochondrial NAD(+)/NADH ratio stimulated a compensatory increase in SIRT1 protein levels that had an anti-inflammatory effect. Our studies reveal the physiologic importance of mitochondrial bioenergetics in the metabolic regulation of sirtuins and cytosolic signaling cascades.
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Abstract
Zinc (Zn2+) is an essential element crucial for growth and development, and also plays a role in cell signaling for cellular processes like cell division and apoptosis. In the mammalian pancreas, Zn2+ is essential for the correct processing, storage, secretion, and action of insulin in beta (β)-cells. Insulin is stored inside secretory vesicles or granules, where two Zn2+ ions coordinate six insulin monomers to form the hexameric-structure on which maturated insulin crystals are based. The total Zn2+ content of the mammalian pancreas is among the highest in the body, and Zn2+ concentration reach millimolar levels in the interior of the dense-core granule. Changes in Zn2+ levels in the pancreas have been found to be associated with diabetes. Hence, the relationship between co-stored Zn2+ and insulin undoubtedly is critical to normal β-cell function. The advances in the field of Zn2+ biology over the last decade have facilitated our understanding of Zn2+ trafficking, its intracellular distribution and its storage. When exocytosis of insulin occurs, insulin granules fuse with the β-cell plasma membrane and release their contents, i.e., insulin as well as substantial amount of free Zn2+, into the extracellular space and the local circulation. Studies increasingly indicate that secreted Zn2+ has autocrine or paracrine signaling in β-cells or the neighboring cells. This review discusses the Zn2+ homeostasis in β-cells with emphasis on the potential signaling role of Zn2+ to islet biology.
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Affiliation(s)
- Yang V Li
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, 346 Irvine Hall, Athens, OH, 45701, USA,
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15
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Li X, Gao X, Shi W, Ma H. Design strategies for water-soluble small molecular chromogenic and fluorogenic probes. Chem Rev 2013; 114:590-659. [PMID: 24024656 DOI: 10.1021/cr300508p] [Citation(s) in RCA: 1188] [Impact Index Per Article: 108.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Xiaohua Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China
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16
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Csordás G, Golenár T, Seifert EL, Kamer KJ, Sancak Y, Perocchi F, Moffat C, Weaver D, Perez SDLF, Bogorad R, Koteliansky V, Adijanto J, Mootha VK, Hajnóczky G. MICU1 controls both the threshold and cooperative activation of the mitochondrial Ca²⁺ uniporter. Cell Metab 2013; 17:976-987. [PMID: 23747253 PMCID: PMC3722067 DOI: 10.1016/j.cmet.2013.04.020] [Citation(s) in RCA: 377] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/02/2013] [Accepted: 04/26/2013] [Indexed: 12/18/2022]
Abstract
Mitochondrial Ca(2+) uptake via the uniporter is central to cell metabolism, signaling, and survival. Recent studies identified MCU as the uniporter's likely pore and MICU1, an EF-hand protein, as its critical regulator. How this complex decodes dynamic cytoplasmic [Ca(2+)] ([Ca(2+)]c) signals, to tune out small [Ca(2+)]c increases yet permit pulse transmission, remains unknown. We report that loss of MICU1 in mouse liver and cultured cells causes mitochondrial Ca(2+) accumulation during small [Ca(2+)]c elevations but an attenuated response to agonist-induced [Ca(2+)]c pulses. The latter reflects loss of positive cooperativity, likely via the EF-hands. MICU1 faces the intermembrane space and responds to [Ca(2+)]c changes. Prolonged MICU1 loss leads to an adaptive increase in matrix Ca(2+) binding, yet cells show impaired oxidative metabolism and sensitization to Ca(2+) overload. Collectively, the data indicate that MICU1 senses the [Ca(2+)]c to establish the uniporter's threshold and gain, thereby allowing mitochondria to properly decode different inputs.
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Affiliation(s)
- György Csordás
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Tünde Golenár
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Erin L Seifert
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kimberli J Kamer
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Yasemin Sancak
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School and Broad Institute, Cambridge, MA 02142, USA
| | - Fabiana Perocchi
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School and Broad Institute, Cambridge, MA 02142, USA; Gene Center, Ludwig-Maximilians-Universität, Munich D-81377, Germany
| | - Cynthia Moffat
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - David Weaver
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sergio de la Fuente Perez
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Roman Bogorad
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Jeffrey Adijanto
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Vamsi K Mootha
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School and Broad Institute, Cambridge, MA 02142, USA.
| | - György Hajnóczky
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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17
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Mallilankaraman K, Cárdenas C, Doonan PJ, Chandramoorthy HC, Irrinki KM, Golenár T, Csordás G, Madireddi P, Yang J, Müller M, Miller R, Kolesar JE, Molgó J, Kaufman B, Hajnóczky G, Foskett JK, Madesh M. MCUR1 is an essential component of mitochondrial Ca2+ uptake that regulates cellular metabolism. Nat Cell Biol 2012. [PMID: 23178883 PMCID: PMC3511605 DOI: 10.1038/ncb2622] [Citation(s) in RCA: 414] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ca(2+) flux across the mitochondrial inner membrane regulates bioenergetics, cytoplasmic Ca(2+) signals and activation of cell death pathways. Mitochondrial Ca(2+) uptake occurs at regions of close apposition with intracellular Ca(2+) release sites, driven by the inner membrane voltage generated by oxidative phosphorylation and mediated by a Ca(2+) selective ion channel (MiCa; ref. ) called the uniporter whose complete molecular identity remains unknown. Mitochondrial calcium uniporter (MCU) was recently identified as the likely ion-conducting pore. In addition, MICU1 was identified as a mitochondrial regulator of uniporter-mediated Ca(2+) uptake in HeLa cells. Here we identified CCDC90A, hereafter referred to as MCUR1 (mitochondrial calcium uniporter regulator 1), an integral membrane protein required for MCU-dependent mitochondrial Ca(2+) uptake. MCUR1 binds to MCU and regulates ruthenium-red-sensitive MCU-dependent Ca(2+) uptake. MCUR1 knockdown does not alter MCU localization, but abrogates Ca(2+) uptake by energized mitochondria in intact and permeabilized cells. Ablation of MCUR1 disrupts oxidative phosphorylation, lowers cellular ATP and activates AMP kinase-dependent pro-survival autophagy. Thus, MCUR1 is a critical component of a mitochondrial uniporter channel complex required for mitochondrial Ca(2+) uptake and maintenance of normal cellular bioenergetics.
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18
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Fernández-Morales JC, Arranz-Tagarro JA, Calvo-Gallardo E, Maroto M, Padín JF, García AG. Stabilizers of neuronal and mitochondrial calcium cycling as a strategy for developing a medicine for Alzheimer's disease. ACS Chem Neurosci 2012; 3:873-83. [PMID: 23173068 DOI: 10.1021/cn3001069] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/29/2012] [Indexed: 12/21/2022] Open
Abstract
For the last two decades, most efforts on new drug development to treat Alzheimer's disease have been focused to inhibit the synthesis of amyloid beta (Aβ), to prevent Aβ deposition, or to clear up Aβ plaques from the brain of Alzheimer's disease (AD) patients. Other pathogenic mechanisms such as the hyperphosphorylation of the microtubular tau protein (that forms neurofibrillary tangles) have also been addressed as, for instance, with inhibitors of the enzyme glycogen synthase-3 kinase beta (GSK3β). However, in spite of their proven efficacy in animal models of AD, all these compounds have so far failed in clinical trials done in AD patients. It seems therefore desirable to explore new concepts and strategies in the field of drug development for AD. We analyze here our hypothesis that a trifunctional chemical entity acting on the L subtype of voltage-dependent Ca(2+) channels (VDCCs) and on the mitochondrial Na(+)/Ca(2+) exchanger (MNCX), and having additional antioxidant properties, may efficiently delay or stop the death of vulnerable neurons in the brain of AD patients. In recent years, evidence has accumulated indicating that enhanced neuronal Ca(2+) cycling (NCC) and futile mitochondrial Ca(2+) cycling (MCC) are central stage in activating calpain and calcineurin, as well as the intrinsic mitochondrial pathway for apoptosis, leading to death of vulnerable neurons. An additional contributing factor to neuronal death is the excess free radical production linked to distortion of Ca(2+) homeostasis. We propose that an hybrid compound containing a dihydropyridine moiety (to block L channels and mitigate Ca(2+) entry) and a benzothiazepine moiety (to block the MNCX and slow down the rate of Ca(2+) efflux from the mitochondrial matrix into the cytosol), as well as a polyphenol moiety (to sequester excess free radicals) could break down the pathological enhanced NCC and MCC, thus delaying the initiation of apoptosis and the death of vulnerable neurons. In so doing, such a trifunctional compound could eventually become a neuroprotective medicine capable of delaying disease progression in AD patients.
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Affiliation(s)
| | - Juan-Alberto Arranz-Tagarro
- Departamento de Farmacología,
Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | | | | | | | - Antonio G. García
- Servicio de Farmacología
Clínica, Instituto de Investigación Sanitaria, Hospital Universitario de La Princesa, Madrid, Spain
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19
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Tarasov AI, Semplici F, Li D, Rizzuto R, Ravier MA, Gilon P, Rutter GA. Frequency-dependent mitochondrial Ca(2+) accumulation regulates ATP synthesis in pancreatic β cells. Pflugers Arch 2012; 465:543-54. [PMID: 23149488 PMCID: PMC3631125 DOI: 10.1007/s00424-012-1177-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 10/25/2012] [Accepted: 10/29/2012] [Indexed: 12/23/2022]
Abstract
Pancreatic β cells respond to increases in glucose concentration with enhanced metabolism, the closure of ATP-sensitive K+ channels and electrical spiking. The latter results in oscillatory Ca2+ influx through voltage-gated Ca2+ channels and the activation of insulin release. The relationship between changes in cytosolic and mitochondrial free calcium concentration ([Ca2+]cyt and [Ca2+]mit, respectively) during these cycles is poorly understood. Importantly, the activation of Ca2+-sensitive intramitochondrial dehydrogenases, occurring alongside the stimulation of ATP consumption required for Ca2+ pumping and other processes, may exert complex effects on cytosolic ATP/ADP ratios and hence insulin secretion. To explore the relationship between these parameters in single primary β cells, we have deployed cytosolic (Fura red, Indo1) or green fluorescent protein-based recombinant-targeted (Pericam, 2mt8RP for mitochondria; D4ER for the ER) probes for Ca2+ and cytosolic ATP/ADP (Perceval) alongside patch-clamp electrophysiology. We demonstrate that: (1) blockade of mitochondrial Ca2+ uptake by shRNA-mediated silencing of the uniporter MCU attenuates glucose- and essentially blocks tolbutamide-stimulated, insulin secretion; (2) during electrical stimulation, mitochondria decode cytosolic Ca2+ oscillation frequency as stable increases in [Ca2+]mit and cytosolic ATP/ADP; (3) mitochondrial Ca2+ uptake rates remained constant between individual spikes, arguing against activity-dependent regulation (“plasticity”) and (4) the relationship between [Ca2+]cyt and [Ca2+]mit is essentially unaffected by changes in endoplasmic reticulum Ca2+ ([Ca2+]ER). Our findings thus highlight new aspects of Ca2+ signalling in β cells of relevance to the actions of both glucose and sulphonylureas.
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Affiliation(s)
- Andrei I Tarasov
- Section of Cell Biology, Division of Diabetes Endocrinology and Metabolism, Department of Medicine, Imperial College London, SW7 2AZ, London, UK
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20
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Csordás G, Várnai P, Golenár T, Sheu SS, Hajnóczky G. Calcium transport across the inner mitochondrial membrane: molecular mechanisms and pharmacology. Mol Cell Endocrinol 2012; 353:109-13. [PMID: 22123069 PMCID: PMC3295916 DOI: 10.1016/j.mce.2011.11.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 11/10/2011] [Accepted: 11/10/2011] [Indexed: 01/21/2023]
Abstract
Growing evidence supports that mitochondrial calcium uptake is important for cell metabolism, signaling and survival. However, both the molecular nature of the mitochondrial Ca(2+) transport sites and the calcium signals they respond to remained elusive. Recent RNA interference studies have identified new candidate proteins for Ca(2+) transport across the inner mitochondrial membrane, including LETM1, MCU, MICU1 and NCLX. The sensitivity of these factors to several drugs has been tested and in parallel, some new inhibitors of mitochondrial Ca(2+) uptake have been described. This paper provides an update on the pharmacological aspects of the molecular mechanisms of the inner mitochondrial membrane Ca(2+) transport.
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Affiliation(s)
- György Csordás
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Peter Várnai
- Department of Physiology, Semmelweis University Budapest, Hungary
| | - Tünde Golenár
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Shey-Shing Sheu
- Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA 19107
| | - György Hajnóczky
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
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21
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Johnson JD, Bround MJ, White SA, Luciani DS. Nanospaces between endoplasmic reticulum and mitochondria as control centres of pancreatic β-cell metabolism and survival. PROTOPLASMA 2012; 249 Suppl 1:S49-S58. [PMID: 22105567 DOI: 10.1007/s00709-011-0349-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 11/07/2011] [Indexed: 05/31/2023]
Abstract
Nanometre-scale spaces between organelles represent focused nodes for signal transduction and the control of cellular decisions. The endoplasmic reticulum (ER) and the mitochondria form dynamic quasi-synaptic interaction nanodomains in all cell types examined, but the functional role of these junctions in cellular metabolism and cell survival remains to be fully understood. In this paper, we review recent evidence that ER Ca(2+) channels, such as the RyR and IP(3)R, can signal specifically across this nanodomain to the adjacent mitochondria to pace basal metabolism, with focus on the pancreatic β-cell. Blocking these signals in the basal state leads to a form of programmed cell death associated with reduced ATP and the induction of calpain-10 and hypoxia-inducible factors. On the other hand, the hyperactivity of this signalling domain plays a deleterious role during classical forms of apoptosis. Thus, the nanospace between ER and mitochondria represents a critical rheostat controlling both metabolism and programmed cell death. Many aspects of the mechanisms underlying this control system remain to be uncovered, and new nanotechnologies are required understand these domains at a molecular level.
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Affiliation(s)
- James D Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada.
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22
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Mitochondria and chromaffin cell function. Pflugers Arch 2012; 464:33-41. [PMID: 22278417 DOI: 10.1007/s00424-012-1074-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 01/05/2012] [Accepted: 01/09/2012] [Indexed: 10/14/2022]
Abstract
Chromaffin cells are an excellent model for stimulus-secretion coupling. Ca(2+) entry through plasma membrane voltage-operated Ca(2+) channels (VOCC) is the trigger for secretion, but the intracellular organelles contribute subtle nuances to the Ca(2+) signal. The endoplasmic reticulum amplifies the cytosolic Ca(2+) ([Ca(2+)](C)) signal by Ca(2+)-induced Ca(2+) release (CICR) and helps generation of microdomains with high [Ca(2+)](C) (HCMD) at the subplasmalemmal region. These HCMD induce exocytosis of the docked secretory vesicles. Mitochondria close to VOCC take up large amounts of Ca(2+) from HCMD and stop progression of the Ca(2+) wave towards the cell core. On the other hand, the increase of [Ca(2+)] at the mitochondrial matrix stimulates respiration and tunes energy production to the increased needs of the exocytic activity. At the end of stimulation, [Ca(2+)](C) decreases rapidly and mitochondria release the Ca(2+) accumulated in the matrix through the Na(+)/Ca(2+) exchanger. VOCC, CICR sites and nearby mitochondria form functional triads that co-localize at the subplasmalemmal area, where secretory vesicles wait ready for exocytosis. These triads optimize stimulus-secretion coupling while avoiding propagation of the Ca(2+) signal to the cell core. Perturbation of their functioning in neurons may contribute to the genesis of excitotoxicity, ageing mental retardation and/or neurodegenerative disorders.
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23
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Mitochondrial matrix Ca2+ as an intrinsic signal regulating mitochondrial motility in axons. Proc Natl Acad Sci U S A 2011; 108:15456-61. [PMID: 21876166 DOI: 10.1073/pnas.1106862108] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The proper distribution of mitochondria is particularly vital for neurons because of their polarized structure and high energy demand. Mitochondria in axons constantly move in response to physiological needs, but signals that regulate mitochondrial movement are not well understood. Aside from producing ATP, Ca(2+) buffering is another main function of mitochondria. Activities of many enzymes in mitochondria are also Ca(2+)-dependent, suggesting that intramitochondrial Ca(2+) concentration is important for mitochondrial functions. Here, we report that mitochondrial motility in axons is actively regulated by mitochondrial matrix Ca(2+). Ca(2+) entry through the mitochondrial Ca(2+) uniporter modulates mitochondrial transport, and mitochondrial Ca(2+) content correlates inversely with the speed of mitochondrial movement. Furthermore, the miro1 protein plays a role in Ca(2+) uptake into the mitochondria, which subsequently affects mitochondrial movement.
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24
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Ma HT, Beaven MA. Regulators of Ca(2+) signaling in mast cells: potential targets for treatment of mast cell-related diseases? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 716:62-90. [PMID: 21713652 DOI: 10.1007/978-1-4419-9533-9_5] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A calcium signal is essential for degranulation, generation of eicosanoids and optimal production of cytokines in mast cells in response to antigen and other stimulants. The signal is initiated by phospholipase C-mediated production of inositol1,4,5-trisphosphate resulting in release of stored Ca(2+) from the endoplasmic reticulum (ER) and Golgi. Depletion of these stores activates influx of extracellular Ca(2+), usually referred to as store-operated calcium entry (SOCE), through the interaction of the Ca(2+)-sensor, stromal interacting molecule-1 (STIM1 ), in ER with Orai1(CRACM1) and transient receptor potential canonical (TRPC) channel proteins in the plasma membrane (PM). This interaction is enabled by microtubular-directed reorganization of ER to form ER/PM contact points or "punctae" in which STIM1 and channel proteins colocalize. The ensuing influx of Ca(2+) replenishes Ca(2+) stores and sustains elevated levels of cytosolic Ca(2+) ions-the obligatory signal for mast-cell activation. In addition, the signal can acquire spatial and dynamic characteristics (e.g., calcium puffs, waves, oscillations) that encode signals for specific functional outputs. This is achieved by coordinated regulation of Ca(2+) fluxes through ATP-dependent Ca(2+)-pumps and ion exchangers in mitochondria, ER and PM. As discussed in this chapter, studies in mast cells revealed much about the mechanisms described above but little about allergic and autoimmune diseases although studies in other types of cells have exposed genetic defects that lead to aberrant calcium signaling in immune diseases. Pharmacologic agents that inhibit or activate the regulatory components of calcium signaling in mast cells are also discussed along with the prospects for development of novel SOCE inhibitors that may prove beneficial in the treatment inflammatory mast-cell related diseases.
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Affiliation(s)
- Hong-Tao Ma
- Laboratory of Molecular Immunology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
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25
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Barsukova A, Komarov A, Hajnóczky G, Bernardi P, Bourdette D, Forte M. Activation of the mitochondrial permeability transition pore modulates Ca2+ responses to physiological stimuli in adult neurons. Eur J Neurosci 2011; 33:831-42. [PMID: 21255127 PMCID: PMC3183752 DOI: 10.1111/j.1460-9568.2010.07576.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The participation of mitochondria in cellular and neuronal Ca(2+) homeostatic networks is now well accepted. Yet, critical tests of specific mitochondrial pathways in neuronal Ca(2+) responses have been hampered because the identity of mitochondrial proteins that must be integrated within this dynamic system remain uncertain. One putative pathway for Ca(2+) efflux from mitochondria exists through the formation of the permeability transition pore (PTP) that is often associated with cellular and neuronal death. Here, we have evaluated neuronal Ca(2+) dynamics and the PTP in single adult neurons in wild-type mice and those missing cyclophilin D (CyPD), a key regulator of the PTP. Using high-resolution time-lapse imaging, we demonstrate that PTP opening only follows simultaneous activation with two physiological stimuli that generate critical threshold levels of cytosolic and mitochondrial Ca(2+) . Our results are the first to demonstrate CyPD-dependent PTP opening in normal neuronal Ca(2+) homeostatic mechanisms not leading to activation of cell death pathways. As neurons in mice lacking CyPD are protected in a number of neurodegenerative disease models, the results suggest that improved viability of CyPD-knockout animals in these pathological states may be due to the transient, rather than persistent, activation of the PTP in mutant mitochondria, thereby shielding neurons from cytoplasmic Ca(2+) overload.
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Affiliation(s)
- Anna Barsukova
- Vollum Institute and Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
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26
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Hajnóczky G, Csordás G. Calcium signalling: fishing out molecules of mitochondrial calcium transport. Curr Biol 2011; 20:R888-91. [PMID: 20971432 DOI: 10.1016/j.cub.2010.09.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cellular energy metabolism, survival and death are controlled by mitochondrial calcium signals originating in the cytoplasm. Now, RNAi studies link three proteins - MICU1, NCLX and LETM1 - to the previously unknown molecular mechanism of mitochondrial calcium transport.
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Affiliation(s)
- György Hajnóczky
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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27
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Rodolfo C, Ciccosanti F, Giacomo GD, Piacentini M, Fimia GM. Proteomic analysis of mitochondrial dysfunction in neurodegenerative diseases. Expert Rev Proteomics 2010; 7:519-42. [PMID: 20653508 DOI: 10.1586/epr.10.43] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alzheimer's, Parkinson's and Huntington's disease, and amyotrophic lateral sclerosis are the most relevant neurodegenerative syndromes worldwide. The identification of the etiology and additional factors contributing to the onset and progression of these diseases is of great importance in order to develop both preventive and therapeutic intervention. A common feature of these pathologies is the formation of aggregates, containing mutated and/or misfolded proteins, in specific subsets of neurons, which progressively undergo functional impairment and die. The relationship between protein aggregation and the molecular events leading to neurodegeneration has not yet been clarified. In the last decade, several lines of evidence pointed to a major role for mitochondrial dysfunction in the onset of these pathologies. Here, we review how proteomics has been applied to neurodegenerative diseases in order to characterize the relationship existing between protein aggregation and mitochondrial alterations. Moreover, we highlight recent advances in the use of proteomics to identify protein modifications caused by oxidative stress. Future developments in this field are expected to significantly contribute to the full comprehension of the molecular mechanisms at the heart of neurodegeneration.
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Affiliation(s)
- Carlo Rodolfo
- Laboratory of Development and Cell Biology, Department of Biology, University of Rome Tor Vergata, Rome, Italy
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28
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Waldeck-Weiermair M, Duan X, Naghdi S, Khan MJ, Trenker M, Malli R, Graier WF. Uncoupling protein 3 adjusts mitochondrial Ca(2+) uptake to high and low Ca(2+) signals. Cell Calcium 2010; 48:288-301. [PMID: 21047682 PMCID: PMC2998676 DOI: 10.1016/j.ceca.2010.10.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 10/07/2010] [Indexed: 12/12/2022]
Abstract
Uncoupling proteins 2 and 3 (UCP2/3) are essential for mitochondrial Ca2+ uptake but both proteins exhibit distinct activities in regard to the source and mode of Ca2+ mobilization. In the present work, structural determinants of their contribution to mitochondrial Ca2+ uptake were explored. Previous findings indicate the importance of the intermembrane loop 2 (IML2) for the contribution of UCP2/3. Thus, the IML2 of UCP2/3 was substituted by that of UCP1. These chimeras had no activity in mitochondrial uptake of intracellularly released Ca2+, while they mimicked the wild-type proteins by potentiating mitochondrial sequestration of entering Ca2+. Alignment of the IML2 sequences revealed that UCP1, UCP2 and UCP3 share a basic amino acid in positions 163, 164 and 167, while only UCP2 and UCP3 contain a second basic residue in positions 168 and 171, respectively. Accordingly, mutants of UCP3 in positions 167 and 171/172 were made. In permeabilized cells, these mutants exhibited distinct Ca2+ sensitivities in regard to mitochondrial Ca2+ sequestration. In intact cells, these mutants established different activities in mitochondrial uptake of either intracellularly released (UCP3R171,E172) or entering (UCP3R167) Ca2+. Our data demonstrate that distinct sites in the IML2 of UCP3 effect mitochondrial uptake of high and low Ca2+ signals.
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29
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Effects of exposure to a time-varying 1.5 T magnetic field on the neurotransmitter-activated increase in intracellular Ca(2+) in relation to actin fiber and mitochondrial functions in bovine adrenal chromaffin cells. Biochim Biophys Acta Gen Subj 2010; 1800:1221-30. [PMID: 20832450 DOI: 10.1016/j.bbagen.2010.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 09/01/2010] [Accepted: 09/03/2010] [Indexed: 11/24/2022]
Abstract
BACKGROUND It has been reported that exposure to electromagnetic fields influences intracellular signal transduction. We studied the effects of exposure to a time-varying 1.5 T magnetic field on membrane properties, membrane cation transport and intracellular Ca(2+) mobilization in relation to signals. We also studied the mechanism of the effect of exposure to the magnetic field on intracellular Ca(2+) release from Ca(2+) stores in adrenal chromaffin cells. METHODS We measured the physiological functions of ER, actin protein, and mitochondria with respect to a neurotransmitter-induced increase in Ca(2+) in chromaffin cells exposed to the time-varying 1.5 T magnetic field for 2h. RESULTS Exposure to the magnetic field significantly reduced the increase in [Ca(2+)]i. The exposure depolarized the mitochondria membrane and lowered oxygen uptake, but did not reduce the intracellular ATP content. Magnetic field-exposure caused a morphological change in intracellular F-actin. F-actin in exposed cells seemed to be less dense than in control cells, but the decrease was smaller than that in cytochalasin D-treated cells. The increase in G-actin (i.e., the decrease in F-actin) due to exposure was recovered by jasplakinolide, but inhibition of Ca(2+) release by the exposure was unaffected. CONCLUSIONS AND GENERAL SIGNIFICANCE These results suggest that the magnetic field-exposure influenced both the ER and mitochondria, but the inhibition of Ca(2+) release from ER was not due to mitochondria inhibition. The effect of eddy currents induced in the culture medium may indirectly influence intracellular actin and suppress the transient increase in [Ca(2+)]i.
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Parekh AB. Decoding cytosolic Ca2+ oscillations. Trends Biochem Sci 2010; 36:78-87. [PMID: 20810284 DOI: 10.1016/j.tibs.2010.07.013] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 07/28/2010] [Accepted: 07/29/2010] [Indexed: 12/19/2022]
Abstract
A rise in cytosolic Ca(2+) concentration is used as a universal signalling mechanism to control biological processes as diverse as exocytosis, contraction, cell growth and cell death. Ca(2+) signals are often presented to cells in the form of Ca(2+) oscillations, with signalling information encoded in both amplitude and frequency of the Ca(2+) spikes. Recent studies have revealed that the sub-cellular spatial profile of the Ca(2+) oscillation is also important in activating cellular responses, thereby suggesting a new mechanism for extracting information from the ubiquitous Ca(2+) oscillation.
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Affiliation(s)
- Anant B Parekh
- Department of Physiology, Anatomy and Genetics, Sherrington Building, Parks Road, Oxford OX1 3PT, UK.
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Csordás G, Várnai P, Golenár T, Roy S, Purkins G, Schneider TG, Balla T, Hajnóczky G. Imaging interorganelle contacts and local calcium dynamics at the ER-mitochondrial interface. Mol Cell 2010; 39:121-32. [PMID: 20603080 DOI: 10.1016/j.molcel.2010.06.029] [Citation(s) in RCA: 555] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 04/09/2010] [Accepted: 06/14/2010] [Indexed: 12/11/2022]
Abstract
The ER-mitochondrial junction provides a local calcium signaling domain that is critical for both matching energy production with demand and the control of apoptosis. Here, we visualize ER-mitochondrial contact sites and monitor the localized [Ca(2+)] changes ([Ca(2+)](ER-mt)) using drug-inducible fluorescent interorganelle linkers. We show that all mitochondria have contacts with the ER, but plasma membrane (PM)-mitochondrial contacts are less frequent because of interleaving ER stacks in both RBL-2H3 and H9c2 cells. Single mitochondria display discrete patches of ER contacts and show heterogeneity in the ER-mitochondrial Ca(2+) transfer. Pericam-tagged linkers revealed IP(3)-induced [Ca(2+)](ER-mt) signals that exceeded 9 microM and endured buffering bulk cytoplasmic [Ca(2+)] increases. Altering linker length to modify the space available for the Ca(2+) transfer machinery had a biphasic effect on [Ca(2+)](ER-mt) signals. These studies provide direct evidence for the existence of high-Ca(2+) microdomains between the ER and mitochondria and suggest an optimal gap width for efficient Ca(2+) transfer.
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Affiliation(s)
- György Csordás
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Stork CJ, Li YV. Zinc release from thapsigargin/IP3-sensitive stores in cultured cortical neurons. J Mol Signal 2010; 5:5. [PMID: 20504366 PMCID: PMC2897781 DOI: 10.1186/1750-2187-5-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 05/26/2010] [Indexed: 11/30/2022] Open
Abstract
Background Changes in ionic concentration have a fundamental effect on numerous physiological processes. For example, IP3-gated thapsigargin sensitive intracellular calcium (Ca2+) storage provides a source of the ion for many cellular signaling events. Less is known about the dynamics of other intracellular ions. The present study investigated the intracellular source of zinc (Zn2+) that has been reported to play a role in cell signaling. Results In primary cultured cortical cells (neurons) labeled with intracellular fluorescent Zn2+ indicators, we showed that intracellular regions of Zn2+ staining co-localized with the endoplasmic reticulum (ER). The latter was identified with ER-tracker Red, a marker for ER. The colocalization was abolished upon exposure to the Zn2+ chelator TPEN, indicating that the local Zn2+ fluorescence represented free Zn2+ localized to the ER in the basal condition. Blockade of the ER Ca2+ pump by thapsigargin produced a steady increase of intracellular Zn2+. Furthermore, we determined that the thapsigargin-induced Zn2+ increase was not dependent on extracellular Ca2+ or extracellular Zn2+, suggesting that it was of intracellular origin. The applications of caged IP3 or IP3-3Kinase inhibitor (to increase available IP3) produced a significant increase in intracellular Zn2+. Conclusions Taken together, these results suggest that Zn2+ is sequestered into thapsigargin/IP3-sensitive stores and is released upon agonist stimulation.
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Affiliation(s)
- Christian J Stork
- Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, USA.
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The contribution of UCP2 and UCP3 to mitochondrial Ca(2+) uptake is differentially determined by the source of supplied Ca(2+). Cell Calcium 2010; 47:433-40. [PMID: 20403634 DOI: 10.1016/j.ceca.2010.03.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 03/08/2010] [Accepted: 03/15/2010] [Indexed: 11/21/2022]
Abstract
The transmission of Ca(2+) signals to mitochondria is an important phenomenon in cell signaling. We have recently reported that the novel uncoupling proteins UCP2 and UCP3 (UCP2/3) are fundamental for mitochondrial Ca(2+) uniport (MCU). In the present study we investigate the contribution of UCP2/3 to mitochondrial accumulation of Ca(2+) either exclusively released from the ER or entering the cell via the store-operated Ca(2+) entry (SOCE) pathway. Using siRNA we demonstrate that constitutively expressed UCP2/3 are essentially involved in mitochondrial sequestration of intracellularly released Ca(2+) but not of that entering the cells via SOCE. However, overexpression of UCP2/3 yielded elevated mitochondrial Ca(2+) uptake from both sources, though it was more pronounced in case of entering Ca(2+), indicating that the expression levels of UCP2/3 are crucial for the capacity of mitochondria to sequester entering Ca(2+). Our data point to distinct UCP2/3-dependent and UCP2/3-independent modes of mitochondrial Ca(2+) sequestration, which may meet the various demands necessary for an adequate organelle Ca(2+) loading from different Ca(2+) sources in intact cells.
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Gellerich FN, Gizatullina Z, Trumbeckaite S, Nguyen HP, Pallas T, Arandarcikaite O, Vielhaber S, Seppet E, Striggow F. The regulation of OXPHOS by extramitochondrial calcium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1018-27. [PMID: 20144582 DOI: 10.1016/j.bbabio.2010.02.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 11/29/2022]
Abstract
Despite extensive research, the regulation of mitochondrial function is still not understood completely. Ample evidence shows that cytosolic Ca2+ has a strategic task in co-ordinating the cellular work load and the regeneration of ATP by mitochondria. Currently, the paradigmatic view is that Cacyt2+ taken up by the Ca2+ uniporter activates the matrix enzymes pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase and isocitrate dehydrogenase. However, we have recently found that Ca2+ regulates the glutamate-dependent state 3 respiration by the supply of glutamate to mitochondria via aralar, a mitochondrial glutamate/aspartate carrier. Since this activation is not affected by ruthenium red, glutamate transport into mitochondria is controlled exclusively by extramitochondrial Ca2+. Therefore, this discovery shows that besides intramitochondrial also extramitochondrial Ca2+ regulates oxidative phosphorylation. This new mechanism acts as a mitochondrial "gas pedal", supplying the OXPHOS with substrate on demand. These results are in line with recent findings of Satrustegui and Palmieri showing that aralar as part of the malate-aspartate shuttle is involved in the Ca2+-dependent transport of reducing hydrogen equivalents (from NADH) into mitochondria. This review summarises results and evidence as well as hypothetical interpretations of data supporting the view that at the surface of mitochondria different regulatory Ca2+-binding sites exist and can contribute to cellular energy homeostasis. Moreover, on the basis of our own data, we propose that these surface Ca2+-binding sites may act as targets for neurotoxic proteins such as mutated huntingtin and others. The binding of these proteins to Ca2+-binding sites can impair the regulation by Ca2+, causing energetic depression and neurodegeneration.
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Affiliation(s)
- Frank N Gellerich
- KeyNeurotek Pharmaceuticals AG, ZENIT Technology Park, Leipziger Str. 44, D-39120 Magdeburg, Germany.
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Mitochondrial Ca2+ channels: Great unknowns with important functions. FEBS Lett 2010; 584:1942-7. [PMID: 20074570 DOI: 10.1016/j.febslet.2010.01.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 12/30/2009] [Accepted: 01/05/2010] [Indexed: 01/31/2023]
Abstract
Mitochondria process local and global Ca(2+) signals. Thereby the spatiotemporal patterns of mitochondrial Ca(2+) signals determine whether the metabolism of these organelles is adjusted or cell death is executed. Mitochondrial Ca(2+) channels of the inner mitochondrial membrane (IMM) actually implement mitochondrial uptake from cytosolic Ca(2+) rises. Despite great efforts in the past, the identity of mitochondrial Ca(2+) channels is still elusive. Numerous studies aimed to characterize mitochondrial Ca(2+) uniport channels and provided a detailed profile of these great unknowns with important functions. This mini-review revisits previous research on the mechanisms of mitochondrial Ca(2+) uptake and aligns them with most recent findings.
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Sultana R, Butterfield DA. Oxidatively modified, mitochondria-relevant brain proteins in subjects with Alzheimer disease and mild cognitive impairment. J Bioenerg Biomembr 2009; 41:441-6. [PMID: 19777328 PMCID: PMC2920455 DOI: 10.1007/s10863-009-9241-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alzheimer disease (AD) is an age-related neurodegenerative disorder, characterized histopathologically by the presence of senile plaques (SP), neurofibrillary tangles and synapse loss in selected brain regions. Positron emission tomography (PET) studies of glucose metabolism revealed decreased energetics in brain of subjects with AD and arguably its earliest form, mild cognitive impairment (MCI), and this decrease correlated with brain structural studies using MRI. The main component of senile plaques is amyloid beta-peptide (Abeta), a 40-42 amino acid peptide that as oligomers is capable of inducing oxidative stress under both in vitro and in vivo conditions and is neurotoxic. In the mitochondria isolated from AD brain, Abeta oligomers that correlated with the reported increased oxidative stress markers in AD have been reported. The markers of oxidative stress have been localized in the brain regions of AD and MCI that show pathological hallmarks of this disease, suggesting the possible role of Abeta in the initiation of the free-radical mediated process and consequently to the build up oxidative stress and AD pathogenesis. Using redox proteomics our laboratory found a number of oxidatively modified brain proteins that are directly in or are associated with the mitochondrial proteome, consistent with a possible involvement of the mitochondrial targeted oxidatively modified proteins in AD progression or pathogenesis. The precise mechanistic link between mitochondrial oxidative damage and role of oligomeric Abeta has not been explicated. In this review, we discuss the role of the oxidation of mitochondria-relevant brain proteins to the pathogenesis and progression of AD.
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Affiliation(s)
- Rukhsana Sultana
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA, Center of Membrane Sciences, University of Kentucky, Lexington, KY 40506-0059, USA, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
| | - D. Allan Butterfield
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA, Center of Membrane Sciences, University of Kentucky, Lexington, KY 40506-0059, USA, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
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Abstract
Calcium signals mediate diverse cellular functions in immunological cells. Early studies with mast cells, then a preeminent model for studying Ca2+-dependent exocytosis, revealed several basic features of calcium signaling in non-electrically excitable cells. Subsequent studies in these and other cells further defined the basic processes such as inositol 1,4,5-trisphosphate-mediated release of Ca2+ from Ca2+ stores in the endoplasmic reticulum (ER); coupling of ER store depletion to influx of external Ca2+ through a calcium-release activated calcium (CRAC) channel now attributed to the interaction of the ER Ca2+ sensor, stromal interacting molecule-1 (STIM1), with a unique Ca2+-channel protein, Orai1/CRACM1, and subsequent uptake of excess Ca2+ into ER and mitochondria through ATP-dependent Ca2+ pumps. In addition, transient receptor potential channels and ion exchangers also contribute to the generation of calcium signals that may be global or have dynamic (e.g., waves and oscillations) and spatial resolution for specific functional readouts. This review discusses past and recent developments in this field of research, the pharmacologic agents that have assisted in these endeavors, and the mast cell as an exemplar for sorting out how calcium signals may regulate multiple outputs in a single cell.
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Affiliation(s)
- Hong-Tao Ma
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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39
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Csordás G, Hajnóczky G. SR/ER-mitochondrial local communication: calcium and ROS. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:1352-62. [PMID: 19527680 DOI: 10.1016/j.bbabio.2009.06.004] [Citation(s) in RCA: 227] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 06/04/2009] [Accepted: 06/05/2009] [Indexed: 02/07/2023]
Abstract
Mitochondria form junctions with the sarco/endoplasmic reticulum (SR/ER), which support signal transduction and biosynthetic pathways and affect organellar distribution. Recently, these junctions have received attention because of their pivotal role in mediating calcium signal propagation to the mitochondria, which is important for both ATP production and mitochondrial cell death. Many of the SR/ER-mitochondrial calcium transporters and signaling proteins are sensitive to redox regulation and are directly exposed to the reactive oxygen species (ROS) produced in the mitochondria and SR/ER. Although ROS has been emerging as a novel signaling entity, the redox signaling of the SR/ER-mitochondrial interface is yet to be elucidated. We describe here possible mechanisms of the mutual interaction between local Ca(2+) and ROS signaling in the control of SR/ER-mitochondrial function.
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Affiliation(s)
- György Csordás
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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40
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Local control of mitochondrial membrane potential, permeability transition pore and reactive oxygen species by calcium and calmodulin in rat ventricular myocytes. J Mol Cell Cardiol 2009; 46:989-97. [PMID: 19318235 DOI: 10.1016/j.yjmcc.2008.12.022] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 12/24/2008] [Accepted: 12/30/2008] [Indexed: 11/21/2022]
Abstract
Calmodulin (CaM) and Ca(2+)/CaM-dependent protein kinase II (CaMKII) play important roles in the development of heart failure. In this study, we evaluated the effects of CaM on mitochondrial membrane potential (DeltaPsi(m)), permeability transition pore (mPTP) and the production of reactive oxygen species (ROS) in permeabilized myocytes; our findings are as follows. (1) CaM depolarized DeltaPsi(m) dose-dependently, but this was prevented by an inhibitor of CaM (W-7) or CaMKII (autocamtide 2-related inhibitory peptide (AIP)). (2) CaM accelerated calcein leakage from mitochondria, indicating the opening of mPTP, however this was prevented by AIP. (3) Cyclosporin A (an inhibitor of the mPTP) inhibited both CaM-induced DeltaPsi(m) depolarization and calcein leakage. (4) CaM increased mitochondrial ROS, which was related to DeltaPsi(m) depolarization and the opening of mPTP. (5) Chelating of cytosolic Ca(2+) by BAPTA, the depletion of SR Ca(2+) by thapsigargin (an inhibitor of SERCA) and the inhibition of mitochondrial Ca(2+) uniporter by Ru360 attenuated the effects of CaM on mitochondrial function. (6) CaM accelerated Ca(2+) extrusion from mitochondria. We conclude that CaM/CaMKII depolarized DeltaPsi(m) and opened mPTP by increasing ROS production, and these effects were strictly regulated by the local increase in cytosolic Ca(2+) concentration, initiated by Ca(2+) releases from the SR. In addition, CaM was involved in the regulation of mitochondrial Ca(2+) homeostasis.
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41
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Alonso MT, Manjarrés IM, García-Sancho J. Modulation of calcium signalling by intracellular organelles seen with targeted aequorins. Acta Physiol (Oxf) 2009; 195:37-49. [PMID: 18983457 DOI: 10.1111/j.1748-1716.2008.01920.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cytosolic Ca(2+) signals that trigger cell responses occur either as localized domains of high Ca(2+) concentration or as propagating Ca(2+) waves. Cytoplasmic organelles, taking up or releasing Ca(2+) to the cytosol, shape the cytosolic signals. On the other hand, Ca(2+) concentration inside organelles is also important in physiology and pathophysiology. Comprehensive study of these matters requires to measure [Ca(2+)] inside organelles and at the relevant cytosolic domains. Aequorins, the best-known chemiluminescent Ca(2+) probes, are excellent for this end as they do not require stressing illumination, have a large dynamic range and a sharp Ca(2+)-dependence, can be targeted to the appropriate location and engineered to have the proper Ca(2+) affinity. Using this methodology, we have evidenced the existence in chromaffin cells of functional units composed by three closely interrelated elements: (1) plasma membrane Ca(2+) channels, (2) subplasmalemmal endoplasmic reticulum and (3) mitochondria. These Ca(2+)-signalling triads optimize Ca(2+) microdomains for secretion and prevent propagation of the Ca(2+) wave towards the cell core. Oscillatory cytosolic Ca(2+) signals originate also oscillations of mitochondrial Ca(2+) in several cell types. The nuclear envelope slows down the propagation of the Ca(2+) wave to the nucleus and filters high frequencies. On the other hand, inositol-trisphosphate may produce direct release of Ca(2+) to the nucleoplasm in GH(3) pituitary cells, thus providing mechanisms for selective nuclear signalling. Aequorins emitting at different wavelengths, prepared by fusion either with green or red fluorescent protein, permit simultaneous and independent monitorization of the Ca(2+) signals in different subcellular domains within the same cell.
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Affiliation(s)
- M T Alonso
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, Valladolid, Spain
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42
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García-Pérez C, Hajnóczky G, Csordás G. Physical coupling supports the local Ca2+ transfer between sarcoplasmic reticulum subdomains and the mitochondria in heart muscle. J Biol Chem 2008; 283:32771-80. [PMID: 18790739 DOI: 10.1074/jbc.m803385200] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In many cell types, transfer of Ca(2+) released via ryanodine receptors (RyR) to the mitochondrial matrix is locally supported by high [Ca(2+)] microdomains at close contacts between the sarcoplasmic reticulum (SR) and mitochondria. Here we studied whether the close contacts were secured via direct physical coupling in cardiac muscle using isolated rat heart mitochondria (RHMs). "Immuno-organelle chemistry" revealed RyR2 and calsequestrin-positive SR particles associated with mitochondria in both crude and Percoll-purified "heavy" mitochondrial fractions (cRHM and pRHM), to a smaller extent in the latter one. Mitochondria-associated vesicles were also visualized by electron microscopy in the RHMs. Western blot analysis detected greatly reduced presence of SR markers (calsequestrin, SERCA2a, and phospholamban) in pRHM, suggesting that the mitochondria-associated particles represented a small subfraction of the SR. Fluorescence calcium imaging in rhod2-loaded cRHM revealed mitochondrial matrix [Ca(2+)] ([Ca(2+)](m)) responses to caffeine-induced Ca(2+) release that were prevented when thapsigargin was added to predeplete the SR or by mitochondrial Ca(2+) uptake inhibitors. Importantly, caffeine failed to increase [Ca(2+)] in the large volume of the incubation medium, suggesting that local Ca(2+) transfer between the SR particles and mitochondria mediated the [Ca(2+)](m) signal. Despite the substantially reduced SR presence, pRHM still displayed a caffeine-induced [Ca(2+)](m) rise comparable with the one recorded in cRHM. Thus, a relatively small fraction of the total SR is physically coupled and transfers Ca(2+) locally to the mitochondria in cardiac muscle. The transferred Ca(2+) stimulates dehydrogenase activity and affects mitochondrial membrane permeabilization, indicating the broad significance of the physical coupling in mitochondrial function.
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Affiliation(s)
- Cecilia García-Pérez
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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43
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Gerasimenko O, Tepikin A. How to measure Ca2+ in cellular organelles? Cell Calcium 2008; 38:201-11. [PMID: 16102822 DOI: 10.1016/j.ceca.2005.06.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 11/27/2022]
Abstract
The review will aim to briefly summarise information on calcium measurements in cellular organelles with emphases on studies conducted in live cells using optical probes. When appropriate we will try to compare the effectiveness of different indicators for intraorganellar calcium measurements. We will consider calcium measurements in endoplasmic reticulum, Golgi apparatus, endosomes/lysosomes, nucleoplasm, nuclear envelope, mitochondria and secretory granules.
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Affiliation(s)
- Oleg Gerasimenko
- The Physiological Laboratory, The University of Liverpool, Crown Street, P.O. Box 147, Liverpool L69 3BX, UK
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Spät A, Szanda G, Csordás G, Hajnóczky G. High- and low-calcium-dependent mechanisms of mitochondrial calcium signalling. Cell Calcium 2008; 44:51-63. [PMID: 18242694 DOI: 10.1016/j.ceca.2007.11.015] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2007] [Revised: 11/23/2007] [Accepted: 11/30/2007] [Indexed: 11/30/2022]
Abstract
The Ca(2+) coupling between endoplasmic reticulum (ER) and mitochondria is central to multiple cell survival and cell death mechanisms. Cytoplasmic [Ca(2+)] ([Ca(2+)](c)) spikes and oscillations produced by ER Ca(2+) release are effectively delivered to the mitochondria. Propagation of [Ca(2+)](c) signals to the mitochondria requires the passage of Ca(2+) across three membranes, namely the ER membrane, the outer mitochondrial membrane (OMM) and the inner mitochondrial membrane (IMM). Strategic positioning of the mitochondria by cytoskeletal transport and interorganellar tethers provides a means to promote the local transfer of Ca(2+) between the ER membrane and OMM. In this setting, even >100 microM [Ca(2+)] may be attained to activate the low affinity mitochondrial Ca(2+) uptake. However, a mitochondrial [Ca(2+)] rise has also been documented during submicromolar [Ca(2+)](c) elevations. Evidence has been emerging that Ca(2+) exerts allosteric control on the Ca(2+) transport sites at each membrane, providing mechanisms that may facilitate the Ca(2+) delivery to the mitochondria. Here we discuss the fundamental mechanisms of ER and mitochondrial Ca(2+) transport, particularly the control of their activity by Ca(2+) and evaluate both high- and low-[Ca(2+)]-activated mitochondrial calcium signals in the context of cell physiology.
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Affiliation(s)
- András Spät
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
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García-Sancho J, Verkhratsky A. Cytoplasmic organelles determine complexity and specificity of calcium signalling in adrenal chromaffin cells. Acta Physiol (Oxf) 2008; 192:263-71. [PMID: 18021325 DOI: 10.1111/j.1748-1716.2007.01812.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Complex and coordinated fluctuations of intracellular free Ca2+ concentration ([Ca2+]c) regulate secretion of adrenaline from chromaffin cells. The physiologically relevant intracellular Ca2+ signals occur either as localized microdomains of high Ca2+ concentrations or as propagating Ca2+ waves, which give rise to global Ca2+ elevations. Intracellular organelles, the endoplasmic reticulum (ER), mitochondria and nuclear envelope, are endowed with powerful Ca2+ transport systems. Calcium uptake and Ca2+ release from these organelles determine the spatial and temporal parameters of Ca2+ signalling events. Furthermore, the ER and mitochondria form close relations with the sites of plasmalemmal Ca2+ entry, creating 'Ca2+ signalling triads' which act as elementary operational units, which regulate exocytosis. Ca2+ ions accumulating in the ER and mitochondria integrate exocytotic activity with energy production and protein synthesis.
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Affiliation(s)
- J García-Sancho
- Departamento de Fisiología, Facultad de Medicina, Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, Valladolid, Spain.
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Joseph SK, Hajnóczky G. IP3 receptors in cell survival and apoptosis: Ca2+ release and beyond. Apoptosis 2008; 12:951-68. [PMID: 17294082 DOI: 10.1007/s10495-007-0719-7] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP(3)Rs) serve to discharge Ca(2+) from ER stores in response to agonist stimulation. The present review summarizes the role of these receptors in models of Ca(2+)-dependent apoptosis. In particular we focus on the regulation of IP(3)Rs by caspase-3 cleavage, cytochrome c, anti-apoptotic proteins and Akt kinase. We also address the evidence that some of the effects of IP(3)Rs in apoptosis may be independent of their ion-channel function. The role of IP(3)Rs in delivering Ca(2+) to the mitochondria is discussed from the perspective of the factors determining inter-organellar dynamics and the spatial proximity of mitochondria and ER membranes.
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Affiliation(s)
- Suresh K Joseph
- Department of Pathology & Cell Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
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Chalmers S, McCarron JG. The mitochondrial membrane potential and Ca2+ oscillations in smooth muscle. J Cell Sci 2007; 121:75-85. [PMID: 18073239 DOI: 10.1242/jcs.014522] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Ca2+ uptake by mitochondria might both modulate the cytosolic Ca2+ concentration ([Ca2+]c) and depolarize the mitochondrial membrane potential (delta Psi m) to limit ATP production. To investigate how physiological Ca2+ signaling might affect energy production, delta Psi m was examined during Ca2+ oscillations in smooth muscle cells. In single, voltage-clamped smooth muscle cells, inhibition of mitochondrial Ca2+ accumulation inhibited inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3]-evoked Ca2+ release and prolonged the time required for restoration of [Ca2+]c following activation of plasmalemmal Ca2+ currents (ICa). Ca2+ could be released from mitochondria immediately (within 15 seconds) after a [Ca2+]c rise evoked by Ins(1,4,5)P3 or ICa. Despite this evidence of mitochondrial Ca2+ accumulation, no change in delta Psi m was observed during single or repetitive [Ca2+]c oscillations evoked by these conditions. Occasionally, spontaneous, repetitive, persistent Ca 2+ oscillations were observed. In these cases, mitochondria displayed stochastic delta Psi m depolarizations, which were independent both of events in neighboring mitochondria and of the timing of the [Ca 2+]c oscillations themselves. Such delta Psi m depolarizations could be mimicked by increased exposure to either fluorescence excitation light or the delta Psi m-sensitive dye tetramethylrhodamine ethyl ester (TMRE) and were inhibited by antioxidants (ascorbic acid, catalase, Trolox and TEMPO) or the mitochondrial permeability transition pore (mPTP)-inhibitor cyclosporin A (CsA). Individual mitochondria within smooth muscle cells might depolarize during repetitive Ca2+ oscillations or during oxidative stress but not during the course of single [Ca2+]c transients evoked by Ca2+ influx or store release.
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Affiliation(s)
- Susan Chalmers
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, John Arbuthnott Building, 27 Taylor Street, Glasgow, G4 0NR, UK
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Mashraqui SH, Subramanian Sundaram, Bhasikuttan A. New ICT probes: synthesis and photophysical studies of N-phenylaza-15-crown-5 aryl/heteroaryl oxadiazoles under acidic condition and in the presence of selected metal ions. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.11.094] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Satrústegui J, Pardo B, Del Arco A. Mitochondrial Transporters as Novel Targets for Intracellular Calcium Signaling. Physiol Rev 2007; 87:29-67. [PMID: 17237342 DOI: 10.1152/physrev.00005.2006] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ca2+signaling in mitochondria is important to tune mitochondrial function to a variety of extracellular stimuli. The main mechanism is Ca2+entry in mitochondria via the Ca2+uniporter followed by Ca2+activation of three dehydrogenases in the mitochondrial matrix. This results in increases in mitochondrial NADH/NAD ratios and ATP levels and increased substrate uptake by mitochondria. We review evidence gathered more than 20 years ago and recent work indicating that substrate uptake, mitochondrial NADH/NAD ratios, and ATP levels may be also activated in response to cytosolic Ca2+signals via a mechanism that does not require the entry of Ca2+in mitochondria, a mechanism depending on the activity of Ca2+-dependent mitochondrial carriers (CaMC). CaMCs fall into two groups, the aspartate-glutamate carriers (AGC) and the ATP-Mg/Picarriers, also named SCaMC (for short CaMC). The two mammalian AGCs, aralar and citrin, are members of the malate-aspartate NADH shuttle, and citrin, the liver AGC, is also a member of the urea cycle. Both types of CaMCs are activated by Ca2+in the intermembrane space and function together with the Ca2+uniporter in decoding the Ca2+signal into a mitochondrial response.
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Affiliation(s)
- Jorgina Satrústegui
- Departamento de Biología Molecular Centro de Biología Molecular "Severo Ochoa" UAM-CSIC, Facultad de Ciencias, Universidad Autónoma, Madrid, Spain.
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Abstract
Uptake of Ca(2+) by mitochondria serves as a regulator of a number of important cellular functions, including energy metabolism, cytoplasmic Ca(2+) signals, and apoptosis. Recent findings reveal that the process of Ca(2+) uptake by the mitochondrial uniporter is itself regulated by Ca(2+) in a temporally complex manner.
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Affiliation(s)
- James W Putney
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences - NIH, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA.
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