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Han JM, Jung HJ. Synergistic Anticancer Effect of a Combination of Berbamine and Arcyriaflavin A against Glioblastoma Stem-like Cells. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27227968. [PMID: 36432068 PMCID: PMC9699626 DOI: 10.3390/molecules27227968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022]
Abstract
Glioblastoma multiforme (GBM) is the most aggressive form of brain tumor. Relapse is frequent and rapid due to glioblastoma stem-like cells (GSCs) that induce tumor initiation, drug resistance, high cancer invasion, immune evasion, and recurrence. Therefore, suppression of GSCs is a powerful therapeutic approach for GBM treatment. Natural compounds berbamine and arcyriaflavin A (ArcA) are known to possess anticancer activity by targeting calcium/calmodulin-dependent protein kinase II gamma (CaMKIIγ) and cyclin-dependent kinase 4 (CDK4), respectively. In this study, we evaluated the effects of concurrent treatment with both compounds on GSCs. Combined treatment with berbamine and ArcA synergistically inhibited cell viability and tumorsphere formation in U87MG- and C6-drived GSCs. Furthermore, simultaneous administration of both compounds potently inhibited tumor growth in a U87MG GSC-grafted chick embryo chorioallantoic membrane (CAM) model. Notably, the synergistic anticancer effect of berbamine and ArcA on GSC growth is associated with the promotion of reactive oxygen species (ROS)- and calcium-dependent apoptosis via strong activation of the p53-mediated caspase cascade. Moreover, co-treatment with both compounds significantly reduced the expression levels of key GSC markers, including CD133, integrin α6, aldehyde dehydrogenase 1A1 (ALDH1A1), Nanog, Sox2, and Oct4. The combined effect of berbamine and ArcA on GSC growth also resulted in downregulation of cell cycle regulatory proteins, such as cyclins and CDKs, by potent inactivation of the CaMKIIγ-mediated STAT3/AKT/ERK1/2 signaling pathway. In addition, a genetic knockdown study using small interfering RNAs (siRNAs) targeting either CaMKIIγ or CDK4 demonstrated that the synergistic anticancer effect of the two compounds on GSCs resulted from dual inhibition of CaMKIIγ and CDK4. Collectively, our findings suggest that a novel combination therapy involving berbamine and ArcA could effectively eradicate GSCs.
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Affiliation(s)
- Jang Mi Han
- Department of Life Science and Biochemical Engineering, Graduate School, Sun Moon University, Asan 31460, Republic of Korea
| | - Hye Jin Jung
- Department of Life Science and Biochemical Engineering, Graduate School, Sun Moon University, Asan 31460, Republic of Korea
- Department of Pharmaceutical Engineering and Biotechnology, Sun Moon University, Asan 31460, Republic of Korea
- Genome-Based BioIT Convergence Institute, Sun Moon University, Asan 31460, Republic of Korea
- Correspondence: ; Tel.: +82-41-530-2354; Fax: +82-41-530-2939
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2
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Serrat R, Oliveira-Pinto A, Marsicano G, Pouvreau S. Imaging mitochondrial calcium dynamics in the central nervous system. J Neurosci Methods 2022; 373:109560. [PMID: 35320763 DOI: 10.1016/j.jneumeth.2022.109560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/04/2022] [Accepted: 03/06/2022] [Indexed: 12/28/2022]
Abstract
Mitochondrial calcium handling is a particularly active research area in the neuroscience field, as it plays key roles in the regulation of several functions of the central nervous system, such as synaptic transmission and plasticity, astrocyte calcium signaling, neuronal activity… In the last few decades, a panel of techniques have been developed to measure mitochondrial calcium dynamics, relying mostly on photonic microscopy, and including synthetic sensors, hybrid sensors and genetically encoded calcium sensors. The goal of this review is to endow the reader with a deep knowledge of the historical and latest tools to monitor mitochondrial calcium events in the brain, as well as a comprehensive overview of the current state of the art in brain mitochondrial calcium signaling. We will discuss the main calcium probes used in the field, their mitochondrial targeting strategies, their key properties and major drawbacks. In addition, we will detail the main roles of mitochondrial calcium handling in neuronal tissues through an extended report of the recent studies using mitochondrial targeted calcium sensors in neuronal and astroglial cells, in vitro and in vivo.
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Affiliation(s)
- Roman Serrat
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Alexandre Oliveira-Pinto
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Giovanni Marsicano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Sandrine Pouvreau
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France.
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3
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Jardim FR, Almeida FJSD, Luckachaki MD, Oliveira MRD. Effects of sulforaphane on brain mitochondria: mechanistic view and future directions. J Zhejiang Univ Sci B 2021; 21:263-279. [PMID: 32253837 DOI: 10.1631/jzus.b1900614] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The organosulfur compound sulforaphane (SFN; C6H11NOS2) is a potent cytoprotective agent promoting antioxidant, anti-inflammatory, antiglycative, and antimicrobial effects in in vitro and in vivo experimental models. Mitochondria are the major site of adenosine triphosphate (ATP) production due to the work of the oxidative phosphorylation (OXPHOS) system. They are also the main site of reactive oxygen species (ROS) production in nucleated human cells. Mitochondrial impairment is central in several human diseases, including neurodegeneration and metabolic disorders. In this paper, we describe and discuss the effects and mechanisms of action by which SFN modulates mitochondrial function and dynamics in mammalian cells. Mitochondria-related pro-apoptotic effects promoted by SFN in tumor cells are also discussed. SFN may be considered a cytoprotective agent, at least in part, because of the effects this organosulfur agent induces in mitochondria. Nonetheless, there are certain points that should be addressed in further experiments, indicated here as future directions, which may help researchers in this field of research.
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Affiliation(s)
- Fernanda Rafaela Jardim
- Forensic Institute, Forensic Toxicology Division, Postmortem Toxicology Sector, CEP 90160-093, Porto Alegre, RS, Brazil
| | - Fhelipe Jolner Souza de Almeida
- Postgraduate Program in Health Sciences (PPGCS), Federal University of Mato Grosso (UFMT), CEP 78060-900, Cuiaba, MT, Brazil
| | | | - Marcos Roberto de Oliveira
- Postgraduate Program in Chemistry (PPGQ), Federal University of Mato Grosso (UFMT), CEP 78060-900, Cuiaba, MT, Brazil.,Department of Biochemistry Prof. "Tuiskon Dick", Federal University of Rio Grande do Sul (UFRGS), CEP 90035-000, Porto Alegre, RS, Brazil
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4
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Waldeck-Weiermair M, Gottschalk B, Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Klec C, Burgstaller S, Bischof H, Depaoli MR, Eroglu E, Malli R, Graier WF. Development and Application of Sub-Mitochondrial Targeted Ca 2 + Biosensors. Front Cell Neurosci 2019; 13:449. [PMID: 31636543 PMCID: PMC6788349 DOI: 10.3389/fncel.2019.00449] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/20/2019] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial Ca2+ uptake into the mitochondrial matrix is a well-established mechanism. However, the sub-organellar Ca2+ kinetics remain elusive. In the present work we identified novel site-specific targeting sequences for the intermembrane space (IMS) and the cristae lumen (CL). We used these novel targeting peptides to develop green- and red- Ca2+ biosensors targeted to the IMS and to the CL. Based on their distinctive spectral properties, and comparable sensitivities these novel constructs were suitable to visualize Ca2+-levels in various (sub) compartments in a multi-chromatic manner. Functional studies that applied these new biosensors revealed that knockdown of MCU and EMRE yielded elevated Ca2+ levels inside the CL but not the IMS in response to IP3-generating agonists. Knockdown of VDAC1, however, strongly impeded the transfer of Ca2+ through the OMM while the cytosolic Ca2+ signal remained unchanged. The novel sub-mitochondrially targeted Ca2+ biosensors proved to be suitable for Ca2+ imaging with high spatial and temporal resolution in a multi-chromatic manner allowing simultaneous measurements. These informative biosensors will facilitate efforts to dissect the complex sub-mitochondrial Ca2+ signaling under (patho)physiological conditions.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Corina T. Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Energy Metabolism Laboratory, Institute of Translational Medicine, D-HEST, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Gabriela Ziomek
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Christiane Klec
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Department of Internal Medicine, Division of Oncology, Medical University of Graz, Graz, Austria
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Maria R. Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Emrah Eroglu
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Wolfgang F. Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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Rachdaoui N, Polo-Parada L, Ismail-Beigi F. Prolonged Exposure to Insulin Inactivates Akt and Erk 1/2 and Increases Pancreatic Islet and INS1E β-Cell Apoptosis. J Endocr Soc 2018; 3:69-90. [PMID: 30697602 PMCID: PMC6344346 DOI: 10.1210/js.2018-00140] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022] Open
Abstract
Chronic hyperinsulinemia, in vivo, increases the resistance of peripheral tissues to insulin by desensitizing insulin signaling. Insulin, in a heterologous manner, can also cause IGF-1 resistance. The aim of the current study was to investigate whether insulin-mediated insulin and IGF-1 resistance develops in pancreatic β-cells and whether this resistance results in β-cell decompensation. Chronic exposure of rat islets or INS1E β-cells to increasing concentrations of insulin decreased AktS473 phosphorylation in response to subsequent acute stimulation with 10 nM insulin or IGF-1. Prolonged exposure to high insulin levels not only inhibited AktS473 phosphorylation, but it also resulted in a significant inhibition of the phosphorylation of P70S6 kinase and Erk1/2 phosphorylation in response to the acute stimulation by glucose, insulin, or IGF-1. Decreased activation of Akt, P70S6K, and Erk1/2 was associated with decreased insulin receptor substrate 2 tyrosine phosphorylation and insulin receptor β-subunit abundance; neither IGF receptor β-subunit content nor its phosphorylation were affected. These signaling impairments were associated with decreased SERCA2 expression, perturbed plasma membrane calcium current and intracellular calcium handling, increased endoplasmic reticulum stress markers such as eIF2αS51 phosphorylation and Bip (GRP78) expression, and increased islet and β-cell apoptosis. We demonstrate that prolonged exposure to high insulin levels induces not only insulin resistance, but in a heterologous manner causes resistance to IGF-1 in rat islets and insulinoma cells resulting in decreased cell survival. These findings suggest the possibility that chronic exposure to hyperinsulinemia may negatively affect β-cell mass by increasing β-cell apoptosis.
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Affiliation(s)
- Nadia Rachdaoui
- Division of Clinical and Molecular Endocrinology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Luis Polo-Parada
- Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
| | - Faramarz Ismail-Beigi
- Division of Clinical and Molecular Endocrinology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
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6
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Synthesis and biological screening for cytotoxic activity of N-substituted indolines and morpholines. Eur J Med Chem 2016; 120:296-303. [DOI: 10.1016/j.ejmech.2016.05.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 05/05/2016] [Accepted: 05/08/2016] [Indexed: 01/16/2023]
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7
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Calcium imaging perspectives in plants. Int J Mol Sci 2014; 15:3842-59. [PMID: 24599077 PMCID: PMC3975371 DOI: 10.3390/ijms15033842] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/18/2014] [Accepted: 02/20/2014] [Indexed: 11/26/2022] Open
Abstract
The calcium ion (Ca2+) is a versatile intracellular messenger. It provides dynamic regulation of a vast array of gene transcriptions, protein kinases, transcription factors and other complex downstream signaling cascades. For the past six decades, intracellular Ca2+ concentration has been significantly studied and still many studies are under way. Our understanding of Ca2+ signaling and the corresponding physiological phenomenon is growing exponentially. Here we focus on the improvements made in the development of probes used for Ca2+ imaging and expanding the application of Ca2+ imaging in plant science research.
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Lopes G, Pinto E, Andrade PB, Valentão P. Antifungal activity of phlorotannins against dermatophytes and yeasts: approaches to the mechanism of action and influence on Candida albicans virulence factor. PLoS One 2013; 8:e72203. [PMID: 23951297 PMCID: PMC3741211 DOI: 10.1371/journal.pone.0072203] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 07/08/2013] [Indexed: 11/28/2022] Open
Abstract
In the last few decades, fungal infections, particularly nosocomial, increased all around the world. This increment stimulated the search for new antifungal agents, especially those derived from nature. Among natural products, those from marine sources have gained prominence in the last years. Purified phlorotannins extracts from three brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus) were screened for their antifungal activity against human pathogenic yeast and filamentous fungi. The purified phlorotannins extracts from the studied seaweeds displayed fungistatic and fungicidal activity against yeast and dermatophytes, respectively, pointing to their interest as anti-dermatophyte agent. C. albicans ATCC 10231 was the most susceptible among yeast, while Epidermophyton floccosum and Trichophyton rubrum were the most susceptible among dermatophytes. Since the antifungal mechanism constitutes an important strategy for limiting the emergence of resistance to the commercially available agents, the mechanism of action of purified phlorotannins extracts was approached. C. nodicaulis and C. usneoides seem to act by affecting the ergosterol composition of the cell membrane of yeast and dermatophyte, respectively. F. spiralis influenced the dermatophyte cell wall composition by reducing the levels of chitin. Phlorotannins also seem to affect the respiratory chain function, as all of the studied species significantly increased the activity of mitochondrial dehydrogenases and increased the incorporation of rhodamine 123 by yeast cells. Phlorotannins from F. spiralis inhibited the dimorphic transition of Candida albicans, leading to the formation of pseudohyphae with diminished capacity to adhere to epithelial cells. This finding is associated with a decrease of C. albicans virulence and capacity to invade host cells and can be potentially interesting for combined antifungal therapy, namely for the control of invasive candidiasis.
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Affiliation(s)
- Graciliana Lopes
- REQUIMTE/Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Eugénia Pinto
- CEQUIMED/Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
- * E-mail:
| | - Paula B. Andrade
- REQUIMTE/Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Patrícia Valentão
- REQUIMTE/Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
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TMBIM3/GRINA is a novel unfolded protein response (UPR) target gene that controls apoptosis through the modulation of ER calcium homeostasis. Cell Death Differ 2012; 19:1013-26. [PMID: 22240901 DOI: 10.1038/cdd.2011.189] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Transmembrane BAX inhibitor motif-containing (TMBIM)-6, also known as BAX-inhibitor 1 (BI-1), is an anti-apoptotic protein that belongs to a putative family of highly conserved and poorly characterized genes. Here we report the function of TMBIM3/GRINA in the control of cell death by endoplasmic reticulum (ER) stress. Tmbim3 mRNA levels are strongly upregulated in cellular and animal models of ER stress, controlled by the PERK signaling branch of the unfolded protein response. TMBIM3/GRINA synergies with TMBIM6/BI-1 in the modulation of ER calcium homeostasis and apoptosis, associated with physical interactions with inositol trisphosphate receptors. Loss-of-function studies in D. melanogaster demonstrated that TMBIM3/GRINA and TMBIM6/BI-1 have synergistic activities against ER stress in vivo. Similarly, manipulation of TMBIM3/GRINA levels in zebrafish embryos revealed an essential role in the control of apoptosis during neuronal development and in experimental models of ER stress. These findings suggest the existence of a conserved group of functionally related cell death regulators across species beyond the BCL-2 family of proteins operating at the ER membrane.
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Baker MJ, Tatsuta T, Langer T. Quality control of mitochondrial proteostasis. Cold Spring Harb Perspect Biol 2011; 3:cshperspect.a007559. [PMID: 21628427 DOI: 10.1101/cshperspect.a007559] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A decline in mitochondrial activity has been associated with aging and is a hallmark of many neurological diseases. Surveillance mechanisms acting at the molecular, organellar, and cellular level monitor mitochondrial integrity and ensure the maintenance of mitochondrial proteostasis. Here we will review the central role of mitochondrial chaperones and proteases, the cytosolic ubiquitin-proteasome system, and the mitochondrial unfolded response in this interconnected quality control network, highlighting the dual function of some proteases in protein quality control within the organelle and for the regulation of mitochondrial fusion and mitophagy.
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Affiliation(s)
- Michael J Baker
- Institute for Genetics, Center for Molecular Medicine (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
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Differential modulation of intracellular Ca2+ responses in B lymphoblasts by mood stabilizers. Int J Neuropsychopharmacol 2010; 13:693-702. [PMID: 19400980 DOI: 10.1017/s1461145709000261] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Irregularities of intracellular calcium (Ca2+) homeostasis have been implicated in the pathophysiology of bipolar disorder (BD). Findings that chronic ex-vivo treatment with lithium modifies lysophosphatidic acid (LPA)-stimulated Ca2+ responses in B lymphoblast cell lines (BLCLs) from BD-I patients and healthy controls, and differentially decreases levels of the type-3 canonical transient receptor potential Ca2+-permeable channel in BLCLs from BD-I patients, support the view that the amelioration of these abnormalities is important in the therapeutic action of lithium. To determine whether other clinically efficacious mood stabilizers share these effects, LPA (100 mum)- and thapsigargin (TG, 200 nm)-stimulated Ca2+ responses were determined in BLCLs from BD-I patients and healthy controls treated acutely (24 h) and chronically (7 d) ex vivo with therapeutically relevant concentrations of lithium (0.75 mm), valproate (0.5 mm), lamotrigine (15 mum) or respective vehicles. Chronic treatment with valproate significantly attenuated LPA-stimulated Ca2+ responses ([downward arrow]8%: F's=9.1-9.4, d.f.=1, 9, p's<0.05) compared to vehicle in BLCLs from BD-I patients and healthy controls, similar to chronic lithium treatment ([downward arrow]8%: F=6.2, d.f.=1, 21, p<0.05), but also attenuated TG-evoked Ca2+ responses ([downward arrow]10% to [downward arrow]19%: F's=5.5-15.5, d.f.=1, 12, p's<0.05). However, chronic lamotrigine treatment did not affect LPA- or TG-stimulated Ca2+ responses. These results suggest that chronic lithium and valproate treatments act differently from lamotrigine in respect of modulation of receptor- and/or capacitance-mediated Ca2+ flux. These differential effects on Ca2+ responses may be relevant to the distinctive clinical profiles of these mood stabilizers.
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12
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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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13
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Murgia M, Giorgi C, Pinton P, Rizzuto R. Controlling metabolism and cell death: at the heart of mitochondrial calcium signalling. J Mol Cell Cardiol 2009; 46:781-8. [PMID: 19285982 PMCID: PMC2851099 DOI: 10.1016/j.yjmcc.2009.03.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 03/05/2009] [Accepted: 03/06/2009] [Indexed: 10/21/2022]
Abstract
Transient increases in intracellular calcium concentration activate and coordinate a wide variety of cellular processes in virtually every cell type. This review describes the main homeostatic mechanisms that control Ca(2+) transients, focusing on the mitochondrial checkpoint. We subsequently extend this paradigm to the cardiomyocyte and to the interplay between cytosol, endoplasmic reticulum and mitochondria that occurs beat-to-beat in excitation-contraction coupling. The mechanisms whereby mitochondria decode fast cytosolic calcium spikes are discussed in the light of the results obtained with recombinant photoproteins targeted to the mitochondrial matrix of contracting cardiomyocytes. Mitochondrial calcium homeostasis is then highlighted as a crucial point of convergence of the environmental signals that mediate cardiac cell death, both by necrosis and by apoptosis. Altogether we point to a role of the mitochondrion as an integrator of calcium signalling and a fundamental decision maker in cardiomyocyte metabolism and survival.
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Affiliation(s)
- Marta Murgia
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padua, Italy
| | - Carlotta Giorgi
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation (ICSI) and Emilia Romagna Laboratory BioPharmaNet, University of Ferrara, Via Borsari 46, 44100 Ferrara; Italy
| | - Paolo Pinton
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation (ICSI) and Emilia Romagna Laboratory BioPharmaNet, University of Ferrara, Via Borsari 46, 44100 Ferrara; Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padua, Italy
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14
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Celsi F, Pizzo P, Brini M, Leo S, Fotino C, Pinton P, Rizzuto R. Mitochondria, calcium and cell death: a deadly triad in neurodegeneration. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:335-44. [PMID: 19268425 DOI: 10.1016/j.bbabio.2009.02.021] [Citation(s) in RCA: 219] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 02/23/2009] [Accepted: 02/24/2009] [Indexed: 12/17/2022]
Abstract
Mitochondrial Ca(2+) accumulation is a tightly controlled process, in turn regulating functions as diverse as aerobic metabolism and induction of cell death. The link between Ca(2+) (dys)regulation, mitochondria and cellular derangement is particularly evident in neurodegenerative disorders, in which genetic models and environmental factors allowed to identify common traits in the pathogenic routes. We will here summarize: i) the current view of mechanisms and functions of mitochondrial Ca(2+) homeostasis, ii) the basic principles of organelle Ca(2+) transport, iii) the role of Ca(2+) in neuronal cell death, and iv) the new information on the pathogenesis of Alzheimer's, Huntington's and Parkinson's diseases, highlighting the role of Ca(2+) and mitochondria.
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Affiliation(s)
- Fulvio Celsi
- Department of Experimental and Diagnostic Medicine, Interdisciplinary Center for the Study of Inflammation, Italy
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15
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Abstract
There is a growing consensus that the various forms of cell death (necrosis, apoptosis and autophagy) are not separated by strict boundaries, but rather share molecular effectors and signaling routes. Among the latter, a clear role is played by calcium (Ca(2+)), the ubiquitous second messenger involved in the control of a broad variety of physiological events. Fine tuning of intracellular Ca(2+) homeostasis by anti- and proapoptotic proteins shapes the Ca(2+) signal to which mitochondria and other cellular effectors are exposed, and hence the efficiency of various cell death inducers. Here, we will review: (i) the evidence linking calcium homeostasis to the regulation of apoptotic, and more recently autophagic cell death, (ii) the discussion of mitochondria as a critical, although not unique checkpoint and (iii) the molecular and functional elucidation of ER/mitochondria contacts, corresponding to the mitochondria-associated membrane (MAM) subfraction and proposed to be a specialized signaling microdomain.
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16
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Rimessi A, Giorgi C, Pinton P, Rizzuto R. The versatility of mitochondrial calcium signals: from stimulation of cell metabolism to induction of cell death. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:808-16. [PMID: 18573473 DOI: 10.1016/j.bbabio.2008.05.449] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 05/22/2008] [Accepted: 05/23/2008] [Indexed: 10/21/2022]
Abstract
Both the contribution of mitochondria to intracellular calcium (Ca(2+)) signalling and the role of mitochondrial Ca(2+) uptake in shaping the cytoplasmic response and controlling mitochondrial function are areas of intense investigation. These studies rely on the appropriate use of emerging techniques coupled with judicious data interpretation to a large extent. The development of targeted probes based on the molecular engineering of luminescent proteins has allowed the specific measurement of Ca(2+) concentration ([Ca(2+)]) and adenosine trisphosphate concentration ([ATP]) in intracellular organelles or cytoplasmic subdomains. This approach has given novel information on different aspects of mitochondrial homeostasis.
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Affiliation(s)
- Alessandro Rimessi
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation and Emilia Romagna Laboratory BioPharmaNet, University of Ferrara, Ferrara, Italy
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17
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A biophysically based mathematical model of unitary potential activity in interstitial cells of Cajal. Biophys J 2008; 95:88-104. [PMID: 18339738 DOI: 10.1529/biophysj.107.122507] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Unitary potential (UP) depolarizations are the basic intracellular events responsible for pacemaker activity in interstitial cells of Cajal (ICCs), and are generated at intracellular sites termed "pacemaker units". In this study, we present a mathematical model of the transmembrane ion flows and intracellular Ca(2+) dynamics from a single ICC pacemaker unit acting at near-resting membrane potential. This model quantitatively formalizes the framework of a novel ICC pacemaking mechanism that has recently been proposed. Model simulations produce spontaneously rhythmic UP depolarizations with an amplitude of approximately 3 mV at a frequency of 0.05 Hz. The model predicts that the main inward currents, carried by a Ca(2+)-inhibited nonselective cation conductance, are activated by depletion of sub-plasma-membrane [Ca(2+)] caused by sarcoendoplasmic reticulum calcium ATPase Ca(2+) sequestration. Furthermore, pacemaker activity predicted by our model persists under simulated voltage clamp and is independent of [IP(3)] oscillations. The model presented here provides a basis to quantitatively analyze UP depolarizations and the biophysical mechanisms underlying their production.
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18
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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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19
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Affiliation(s)
- Diana Stojanovski
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Universität Freiburg, Hermann-Herder-Strasse 7, D-79104 Freiburg, Germany
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20
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Pinton P, Rimessi A, Romagnoli A, Prandini A, Rizzuto R. Biosensors for the detection of calcium and pH. Methods Cell Biol 2007; 80:297-325. [PMID: 17445701 DOI: 10.1016/s0091-679x(06)80015-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Paolo Pinton
- Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation (ICSI), University of Ferrara, I-44100 Ferrara, Italy
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21
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Porcelli AM, Ghelli A, Zanna C, Pinton P, Rizzuto R, Rugolo M. pH difference across the outer mitochondrial membrane measured with a green fluorescent protein mutant. Biochem Biophys Res Commun 2005; 326:799-804. [PMID: 15607740 DOI: 10.1016/j.bbrc.2004.11.105] [Citation(s) in RCA: 221] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Indexed: 10/26/2022]
Abstract
In this study we have generated a EYFP targeted to the mitochondrial intermembrane space (MIMS-EYFP) to determine for the first time the pH within this compartment. The fragment encoding HAI-tagged EYFP was fused with the C-terminus of glycerol-phosphate dehydrogenase, an integral protein of the inner mitochondrial membrane. Human ECV304 cells transiently transfected with MIMS-EYFP showed the typical mitochondrial network, co-localized with MitoTracker Red. Following the calibration procedure, an estimation of the pH value in the intermembrane space was obtained. This value (6.88+/-0.09) was significantly lower than that determined in the cytosol after transfection with a cytosolic EYFP (7.59+/-0.01). Further, the pH of the mitochondrial matrix, determined with a EYFP targeted to this subcompartment, was 0.9 pH units higher than that in the intermembrane space. In conclusion, MIMS-EYFP represents a novel powerful tool to monitor pH changes in the mitochondrial intermembrane space of live cells.
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Affiliation(s)
- Anna Maria Porcelli
- Department of Biology, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
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22
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Koopman WJH, Renders M, Oosterhof A, van Kuppevelt TH, van Engelen BGM, Willems PHGM. Upregulation of Ca2+ removal in human skeletal muscle: a possible role for Ca2+-dependent priming of mitochondrial ATP synthesis. Am J Physiol Cell Physiol 2003; 285:C1263-9. [PMID: 12839829 DOI: 10.1152/ajpcell.00097.2003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In muscle, ATP is required for the powerstroke of the myosin head, the detachment of actin and myosin filaments, and the reuptake of Ca2+ into the sarcoplasmic reticulum. During contraction-relaxation, large amounts of ATP are consumed at the sites of action of the myosin-ATPase and sarcoplasmic reticulum Ca2+-ATPase. The present study addresses the consequences of a reduction in mitochondrial ATP production capacity on sarcoplasmic Ca2+ handling. To this end, myotubes were cultured from patient quadriceps with a biochemically defined decrease in the maximal rate of mitochondrial ATP production and were loaded with indo 1 for imaging of sarcoplasmic Ca2+ changes in real time by confocal microscopy. Myotubes were field-stimulated with 10-ms pulses of 16 V to evoke transient rises in sarcoplasmic Ca2+ concentration ([Ca2+]S). Three single pulses, two pulse trains (1 Hz), and one single pulse were applied in succession to mimic changing workloads. Control myotubes displayed [Ca2+]S transients with an amplitude that was independent of the strength of the stimulus. Intriguingly, the rate of sarcoplasmic Ca2+ removal (CRR) was significantly upregulated during the second and subsequent transients. In myotubes with a reduced mitochondrial ATP production capacity, the amplitude of the [Ca2+]S transients was markedly increased at higher stimulus intensities. Moreover, upregulation of the CRR was significantly decreased compared with control. Taken together, these results are in good agreement with a tight coupling between mitochondrial ATP production and sarcoplasmic Ca2+ handling. Moreover, they support the existence of a relatively long-lasting mitochondrial memory for sarcoplasmic [Ca2+] rises. This memory, which manifested itself as an increase in CRR upon recurrent stimulation, was impaired in patient myotubes with a reduced mitochondrial ATP production capacity.
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Affiliation(s)
- Werner J H Koopman
- 160 Biochemistry NCMLS, University Medical Center Nijmegen, PO Box 9101, NL-6500 HB Nijmegen, The Netherlands
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23
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Rüdel R, Brinkmeier H. 76th ENMC International Workshop: pathophysiology and therapy in the mdx mouse 21-23 January 2000, Naarden, The Netherlands. Neuromuscul Disord 2002; 12:415-20. [PMID: 12062261 DOI: 10.1016/s0960-8966(01)00327-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- R Rüdel
- Universität Ulm, Abt. für Allgemeine Physiologie, 89069, Ulm, Germany.
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24
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Abstract
The aging process at the cellular, organ and whole organism levels is in many respects a mystery. A common bias among those who study aging is that cellular homeostasis "generally falls apart". The assumption of a general deterioration in cellular homeostasis does not take into account that many individuals age quite well maintaining even robust physiological and mental functions. One facet of aging studies that has come to the forefront is the impact of age on the control of the ion messenger, calcium. Emerging evidence suggests that despite age-related declines in any one component or multiple components of the calcium buffering systems, compensatory mechanisms may be able to maintain overall calcium homeostasis. This brief review focuses specifically on the ability of peripheral neurons to maintain control of the ion messenger calcium with advancing age. In addition, the idea that the impact of age on calcium homeostasis may be more subtle due to complex and integrated mechanisms that control this ion is discussed.
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Affiliation(s)
- William J Pottorf
- Department of Pharmacology, School of Medicine, Loma Linda University, CA 92350, USA
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25
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Porcelli AM, Pinton P, Ainscow EK, Chiesa A, Rugolo M, Rutter GA, Rizzuto R. Targeting of reporter molecules to mitochondria to measure calcium, ATP, and pH. Methods Cell Biol 2002; 65:353-80. [PMID: 11381603 DOI: 10.1016/s0091-679x(01)65021-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- A M Porcelli
- Department of Biology, University of Bologna, 40126 Bologna, Italy
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26
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Hanson MR, Köhler RH. GFP imaging: methodology and application to investigate cellular compartmentation in plants. JOURNAL OF EXPERIMENTAL BOTANY 2001; 52:529-539. [PMID: 11373302 DOI: 10.1093/jexbot/52.356.529] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The cloning of the jellyfish gfp (green fluorescent protein) gene and its alteration for expression in subcellular locations in transformed plant cells have resulted in new views of intracellular organization and dynamics. Fusions of GFP with entire proteins of known or unknown function have shown where the proteins are located and whether the proteins move from one compartment to another. GFP and variants with different spectral properties have been deliberately targeted to separate compartments to determine their size, shape, mobility, and dynamic changes during development or environmental response. Fluorescence Resonance Energy Transfer (FRET) between GFP variants can discern protein/ protein interactions. GFP has been used as a sensor to detect changes or differences in calcium, pH, voltage, metal, and enzyme activity. Photobleaching and photoactivation of GFP as well as fluorescence correlation spectroscopy can measure rates of diffusion and movement of GFP within or between compartments. This review covers past applications of these methods as well as promising developments in GFP imaging for understanding the functional organization of plant cells.
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Affiliation(s)
- M R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Biotechnology Building, Ithaca, NY 14853, USA.
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27
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Treves S, Feriotto G, Moccagatta L, Gambari R, Zorzato F. Molecular cloning, expression, functional characterization, chromosomal localization, and gene structure of junctate, a novel integral calcium binding protein of sarco(endo)plasmic reticulum membrane. J Biol Chem 2000; 275:39555-68. [PMID: 11007777 DOI: 10.1074/jbc.m005473200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Screening a cDNA library from human skeletal muscle and cardiac muscle with a cDNA probe derived from junctin led to the isolation of two groups of cDNA clones. The first group displayed a deduced amino acid sequence that is 84% identical to that of dog heart junctin, whereas the second group had a single open reading frame that encoded a polypeptide with a predicted mass of 33 kDa, whose first 78 NH(2)-terminal residues are identical to junctin whereas its COOH terminus domain is identical to aspartyl beta-hydroxylase, a member of the alpha-ketoglutarate-dependent dioxygenase family. We named the latter amino acid sequence junctate. Northern blot analysis indicates that junctate is expressed in a variety of human tissues including heart, pancreas, brain, lung, liver, kidney, and skeletal muscle. Fluorescence in situ hybridization analysis revealed that the genetic loci of junctin and junctate map to the same cytogenetic band on human chromosome 8. Analysis of intron/exon boundaries of the genomic BAC clones demonstrate that junctin, junctate, and aspartyl beta-hydroxylase result from alternative splicing of the same gene. The predicted lumenal portion of junctate is enriched in negatively charged residues and is able to bind calcium. Scatchard analysis of equilibrium (45)Ca(2+) binding in the presence of a physiological concentration of KCl demonstrate that junctate binds 21.0 mol of Ca(2+)/mol protein with a k(D) of 217 +/- 20 microm (n = 5). Tagging recombinant junctate with green fluorescent protein and expressing the chimeric polypeptide in COS-7-transfected cells indicates that junctate is located in endoplasmic reticulum membranes and that its presence increases the peak amplitude and transient calcium released by activation of surface membrane receptors coupled to InsP(3) receptor activation. Our study shows that alternative splicing of the same gene generates the following functionally distinct proteins: an enzyme (aspartyl beta-hydroxylase), a structural protein of SR (junctin), and a membrane-bound calcium binding protein (junctate).
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MESH Headings
- Alternative Splicing
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- COS Cells
- Calcium/metabolism
- Calcium-Binding Proteins/biosynthesis
- Calcium-Binding Proteins/chemistry
- Calcium-Binding Proteins/genetics
- Calcium-Binding Proteins/metabolism
- Carrier Proteins/chemistry
- Chromatography
- Chromosome Mapping
- Chromosomes, Human, Pair 8
- Cloning, Molecular
- DNA, Complementary/metabolism
- Electrophoresis, Polyacrylamide Gel
- Exons
- Gene Library
- Glutathione Transferase
- Green Fluorescent Proteins
- Humans
- In Situ Hybridization, Fluorescence
- Intracellular Membranes/metabolism
- Introns
- Kidney/metabolism
- Kinetics
- Luminescent Proteins/metabolism
- Membrane Proteins/biosynthesis
- Membrane Proteins/chemistry
- Membrane Proteins/genetics
- Microsomes/metabolism
- Mixed Function Oxygenases/chemistry
- Models, Genetic
- Molecular Sequence Data
- Muscle Proteins/chemistry
- Muscle, Skeletal/metabolism
- Myocardium/metabolism
- Polymerase Chain Reaction
- Potassium Chloride/metabolism
- Protein Structure, Tertiary
- Rabbits
- Recombinant Fusion Proteins/metabolism
- Recombinant Proteins/metabolism
- Sarcoplasmic Reticulum/metabolism
- Sepharose/metabolism
- Sequence Analysis, Protein
- Sequence Homology, Amino Acid
- Time Factors
- Tissue Distribution
- Transfection
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Affiliation(s)
- S Treves
- Departments of Anaesthesia and Research, Hebelstrasse 20, Kantonsspital, 4031 Basel, Switzerland
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28
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Gunter TE, Buntinas L, Sparagna G, Eliseev R, Gunter K. Mitochondrial calcium transport: mechanisms and functions. Cell Calcium 2000; 28:285-96. [PMID: 11115368 DOI: 10.1054/ceca.2000.0168] [Citation(s) in RCA: 279] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ca(2+)transport across the mitochondrial inner membrane is facilitated by transporters having four distinct sets of characteristics as well as through the Ca(2+)-induced mitochondrial permeability transition pore (PTP). There are two modes of inward transport, referred to as the Ca(2+)uniporter and the rapid mode or RaM. There are also two distinct mechanisms mediating outward transport, which are not associated with the PTP, referred to as the Na(+)-dependent and the Na(+)-independent Ca(2+)efflux mechanisms. Several important functions have been proposed for these mechanisms, including control of the metabolic rate for cellular energy (ATP) production, modulation of the amplitude and shape of cytosolic Ca(2+)transients, and induction of apoptosis through release of cytochrome c from the mitochondrial inter membrane space into the cytosolic space. The goals of this review are to survey the literature describing the characteristics of the mechanisms of mitochondrial Ca(2+)transport and their proposed physiological functions, emphasizing the more recent contributions, and to consider how the observed characteristics of the mitochondrial Ca(2+)transport mechanisms affect our understanding of their functions.
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Affiliation(s)
- T E Gunter
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
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29
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Gurney AM, Drummond RM, Fay FS. Calcium signalling in sarcoplasmic reticulum, cytoplasm and mitochondria during activation of rabbit aorta myocytes. Cell Calcium 2000; 27:339-51. [PMID: 11013464 DOI: 10.1054/ceca.2000.0124] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study investigated the relationship between cytoplasmic, mitochondrial, and sarcoplasmic reticulum (SR) [Ca(2+)] in rabbit aorta smooth muscle cells, following cell activation. Smooth muscle cells were loaded with the Ca(2+)-sensitive fluorescent indicator Mag-Fura-2-AM, and then either permeabilized by exposure to saponin, or dialyzed with a patch pipette in the whole-cell configuration to remove cytoplasmic indicator. When the intracellular solution contained millimolar EGTA or BAPTA, activation of SR Ca(2+)release through IP(3)or ryanodine receptors induced a decrease in the [Ca(2+)] reported by Mag-Fura-2. However, when EGTA was present at < or =100 microM, the same stimuli caused an increase in the [Ca(2+)] reported by Mag-Fura-2. The increase in [Ca(2+)] caused by phenylephrine or caffeine was delayed, and prolonged, with respect to the cytoplasmic Ca(2+)transient. Evidence is presented that this Mag-Fura-2 signal reflected a rise in mitochondrial [Ca(2+)]. Agents that inhibit mitochondrial function, such as FCCP or cyanide in combination with oligomycin B, converted the increase in organelle Mag-Fura-2 fluorescence to a decrease, while also prolonging the cytoplasmic Ca(2+)transient. There was considerable similarity between the localization of Mag-Fura-2 fluorescence and the mitochondria-selective indicator tetramethylrhodamine ethyl ester. Thus, we propose that there is close functional integration between the SR and mitochondria in aorta smooth muscle cells, with mitochondria taking up Ca(2+)from the cytoplasm following cell activation.
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MESH Headings
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Caffeine/pharmacology
- Calcium/metabolism
- Calcium Signaling
- Cells, Cultured/drug effects
- Cells, Cultured/metabolism
- Cytoplasm/drug effects
- Cytoplasm/metabolism
- Dialysis
- Egtazic Acid/analogs & derivatives
- Egtazic Acid/pharmacology
- Fluorescence
- Fluorescent Dyes/metabolism
- Fura-2/analogs & derivatives
- Fura-2/metabolism
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate/pharmacology
- Intracellular Membranes/metabolism
- Male
- Mitochondria, Muscle/drug effects
- Mitochondria, Muscle/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Phenylephrine/pharmacology
- Rabbits
- Saponins/metabolism
- Sarcoplasmic Reticulum/drug effects
- Sarcoplasmic Reticulum/metabolism
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Affiliation(s)
- A M Gurney
- Department of Physiology and Pharmacology, University of Strathclyde, Strathclyde Institute for Biomedical Sciences, Glasgow, UK
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30
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Pottorf WJ, Duckles SP, Buchholz JN. Mechanisms of calcium buffering in adrenergic neurones and effects of ageing: testing the limits of homeostasis. JOURNAL OF AUTONOMIC PHARMACOLOGY 2000; 20:63-75. [PMID: 11095545 DOI: 10.1046/j.1365-2680.2000.00165.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- W J Pottorf
- Department of Pharmacology, Loma Linda University School of Medicine, CA 92350, USA
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31
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Fu L, Miseta A, Hunton D, Marchase RB, Bedwell DM. Loss of the major isoform of phosphoglucomutase results in altered calcium homeostasis in Saccharomyces cerevisiae. J Biol Chem 2000; 275:5431-40. [PMID: 10681519 DOI: 10.1074/jbc.275.8.5431] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphoglucomutase (PGM) is a key enzyme in glucose metabolism, where it catalyzes the interconversion of glucose 1-phosphate (Glc-1-P) and glucose 6-phosphate (Glc-6-P). In this study, we make the novel observation that PGM is also involved in the regulation of cellular Ca(2+) homeostasis in Saccharomyces cerevisiae. When a strain lacking the major isoform of PGM (pgm2Delta) was grown on media containing galactose as sole carbon source, its rate of Ca(2+) uptake was 5-fold higher than an isogenic wild-type strain. This increased rate of Ca(2+) uptake resulted in a 9-fold increase in the steady-state total cellular Ca(2+) level. The fraction of cellular Ca(2+) located in the exchangeable pool in the pgm2Delta strain was found to be as large as the exchangeable fraction observed in wild-type cells, suggesting that the depletion of Golgi Ca(2+) stores is not responsible for the increased rate of Ca(2+) uptake. We also found that growth of the pgm2Delta strain on galactose media is inhibited by 10 microM cyclosporin A, suggesting that activation of the calmodulin/calcineurin signaling pathway is required to activate the Ca(2+) transporters that sequester the increased cytosolic Ca(2+) load caused by this high rate of Ca(2+) uptake. We propose that these Ca(2+)-related alterations are attributable to a reduced metabolic flux between Glc-1-P and Glc-6-P due to a limitation of PGM enzymatic activity in the pgm2Delta strain. Consistent with this hypothesis, we found that this "metabolic bottleneck" resulted in an 8-fold increase in the Glc-1-P level compared with the wild-type strain, while the Glc-6-P and ATP levels were normal. These results suggest that Glc-1-P (or a related metabolite) may participate in the control of Ca(2+) uptake from the environment.
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Affiliation(s)
- L Fu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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32
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Pottorf WJ, Duckles SP, Buchholz JN. Adrenergic nerves compensate for a decline in calcium buffering during ageing. JOURNAL OF AUTONOMIC PHARMACOLOGY 2000; 20:1-13. [PMID: 11048956 DOI: 10.1046/j.1365-2680.2000.00153.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The ubiquitous involvement of intracellular calcium ([Ca2+]i) in multiple neuronal pathways has led investigators to suggest that dysfunction of calcium homeostasis may be the primary mediator of age-related neuronal degeneration. Recently, it was shown that sympathetic neurones from superior cervical ganglion (SCG) of aged rats demonstrate decreased sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA) function and that aged neurones are more dependent upon mitochondria to control K+-evoked [Ca2+]i transients. 2. Therefore, in the present study we investigated age-related changes in ATP-dependent calcium pumps of plasma membrane Ca2+-ATPase (PMCA) and SERCA in acutely dissociated SCG cells from Fischer-344 rats aged 6 and 20 months. To distinguish between PMCA and SERCA pump activity, we applied the Ca2+-ATPase blocker vanadate and measured rates of recovery of K+-evoked [Ca2+]i transients by fura-2 microfluorometry. 3. Young SCG cells showed a biphasic response to vanadate over the vanadate concentration range (0.01-100 microM); however, old SCG cells showed only a single response over the same concentration range. Additionally, old SCG cells showed a greater sensitivity to Ca2+-ATPase blockade by vanadate. 4. The contribution of mitochondrial calcium uptake to regulate [Ca2+]i was also investigated. To measure the impact of mitochondrial calcium uptake, PMCAs and SERCAs were blocked with vanadate (100 microM) and extracellular sodium was replaced with tetraethylammonium (TEA) to block Na+/Ca2+-exchange. Treated SCG cells showed a decline of 50% in rate of recovery of [Ca2+]i in both 6- and 20-month-old cells; however, this effect did not vary with age. 5. These data suggest that there is an age-related decline in function of SERCAs, with an increased reliance on PMCAs to control high K+-evoked [Ca2+]i transients. In addition, there appears to be no age-related change in the capacity of the mitochondria to restore [Ca2+]i transients to basal levels.
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Affiliation(s)
- W J Pottorf
- Department of Pharmacology, Loma Linda University School of Medicine, CA 92350, USA
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33
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Skulachev VP. Mitochondrial physiology and pathology; concepts of programmed death of organelles, cells and organisms. Mol Aspects Med 1999; 20:139-84. [PMID: 10626278 DOI: 10.1016/s0098-2997(99)00008-4] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The review summarizes the present state of our knowledge concerning alternative functions of mitochondria, namely energy conservation in forms of protonic potential and ATP, thermoregulatory energy dissipation as heat, production of useful substances, decomposition of harmful substances, control of cellular processes. The recent progress in understanding of some mitochondrion-linked pathologies is described. The role of reactive oxygen species in these processes is stressed. Possible mechanisms of programmed death of mitochondrion (mitoptosis), cell (apoptosis) and organism (phenoptosis) are considered. A concept is put forward assuming that mitoptosis is involved in some types of apoptosis whereas apoptosis can be a part of a phenoptotic cascade. It is hypothesized that septic shock, as well as the stress-induced brain and heart ischemic diseases and cancer, exemplify mechanisms of phenoptosis purifying population, community of organisms or kin from dangerous or useless individuals.
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Affiliation(s)
- V P Skulachev
- Department of Bioenergetics, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
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