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Ikeda A, Meng H, Taniguchi D, Mio M, Funayama M, Nishioka K, Yoshida M, Li Y, Yoshino H, Inoshita T, Shiba-Fukushima K, Okubo Y, Sakurai T, Amo T, Aiba I, Saito Y, Saito Y, Murayama S, Atsuta N, Nakamura R, Tohnai G, Izumi Y, Morita M, Tamura A, Kano O, Oda M, Kuwabara S, Yamashita T, Sone J, Kaji R, Sobue G, Imai Y, Hattori N. CHCHD2 P14L, found in amyotrophic lateral sclerosis, exhibits cytoplasmic mislocalization and alters Ca 2+ homeostasis. PNAS NEXUS 2024; 3:pgae319. [PMID: 39131911 PMCID: PMC11316225 DOI: 10.1093/pnasnexus/pgae319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 07/22/2024] [Indexed: 08/13/2024]
Abstract
CHCHD2 and CHCHD10, linked to Parkinson's disease and amyotrophic lateral sclerosis-frontotemporal dementia (ALS), respectively, are mitochondrial intermembrane proteins that form a heterodimer. This study aimed to investigate the impact of the CHCHD2 P14L variant, implicated in ALS, on mitochondrial function and its subsequent effects on cellular homeostasis. The missense variant of CHCHD2, P14L, found in a cohort of patients with ALS, mislocalized CHCHD2 to the cytoplasm, leaving CHCHD10 in the mitochondria. Drosophila lacking the CHCHD2 ortholog exhibited mitochondrial degeneration. In contrast, human CHCHD2 P14L, but not wild-type human CHCHD2, failed to suppress this degeneration, suggesting that P14L is a pathogenic variant. The mitochondrial Ca2+ buffering capacity was reduced in Drosophila neurons expressing human CHCHD2 P14L. The altered Ca2+-buffering phenotype was also observed in cultured human neuroblastoma SH-SY5Y cells expressing CHCHD2 P14L. In these cells, transient elevation of cytoplasmic Ca2+ facilitated the activation of calpain and caspase-3, accompanied by the processing and insolubilization of TDP-43. These observations suggest that CHCHD2 P14L causes abnormal Ca2+ dynamics and TDP-43 aggregation, reflecting the pathophysiology of ALS.
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Affiliation(s)
- Aya Ikeda
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Hongrui Meng
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Daisuke Taniguchi
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Muneyo Mio
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Manabu Funayama
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Center for Genomic and Regenerative Medicine, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kenya Nishioka
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Mari Yoshida
- Department of Neuropathology, Institute for Medical Science of Aging, Aichi Medical University, Nagakute, Aichi 480-1195, Japan
| | - Yuanzhe Li
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Hiroyo Yoshino
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Tsuyoshi Inoshita
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kahori Shiba-Fukushima
- Department of Drug Development for Parkinson's Disease, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Yohei Okubo
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Taku Amo
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa 239-8686, Japan
| | - Ikuko Aiba
- Department of Neurology, NHO Higashinagoya National Hospital, Meito-ku, Nagoya, Aichi 465-8620, Japan
| | - Yufuko Saito
- Department of Neurology, NHO Higashinagoya National Hospital, Meito-ku, Nagoya, Aichi 465-8620, Japan
| | - Yuko Saito
- Brain Bank for Aging Research (Department of Neuropathology), Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo 173-0015, Japan
| | - Shigeo Murayama
- Brain Bank for Aging Research (Department of Neuropathology), Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo 173-0015, Japan
- Brain Bank for Neurodevelopmental, Neurological and Psychiatric Disorders, United Graduate School of Child Development, Osaka University, Osaka 565-0871, Japan
| | - Naoki Atsuta
- Department of Neurology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan
| | - Ryoichi Nakamura
- Department of Neurology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan
| | - Genki Tohnai
- Division of ALS Research, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan
| | - Yuishin Izumi
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima 770-8503, Japan
| | - Mitsuya Morita
- Division of Neurology, Department of Internal Medicine, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan
| | - Asako Tamura
- Department of Neurology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Osamu Kano
- Department of Neurology, Toho University Faculty of Medicine, Ota-ku, Tokyo 143-8541, Japan
| | - Masaya Oda
- Department of Neurology, Vihara Hananosato Hospital, Miyoshi, Hiroshima 728-0001, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba 260-8670, Japan
| | - Toru Yamashita
- Department of Neurology, Okayama University Graduate School of Medicine, Kita-ku, Okayama 700-8558, Japan
| | - Jun Sone
- Department of Neuropathology, Institute for Medical Science of Aging, Aichi Medical University, Nagakute, Aichi 480-1195, Japan
| | - Ryuji Kaji
- Department of Clinical Neuroscience, Tokushima University, Tokushima 770-8503, Japan
| | - Gen Sobue
- Aichi Medical University, Nagakute, Aichi 480-1195, Japan
| | - Yuzuru Imai
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Department of Drug Development for Parkinson's Disease, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
- Neurodegenerative Disorders Collaborative Laboratory, RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan
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Wang J, Jiang J, Hu H, Chen L. MCU complex: Exploring emerging targets and mechanisms of mitochondrial physiology and pathology. J Adv Res 2024:S2090-1232(24)00075-4. [PMID: 38417574 DOI: 10.1016/j.jare.2024.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/16/2024] [Accepted: 02/17/2024] [Indexed: 03/01/2024] Open
Abstract
BACKGROUND Globally, the onset and progression of multiple human diseases are associated with mitochondrial dysfunction and dysregulation of Ca2+ uptake dynamics mediated by the mitochondrial calcium uniporter (MCU) complex, which plays a key role in mitochondrial dysfunction. Despite relevant studies, the underlying pathophysiological mechanisms have not yet been fully elucidated. AIM OF REVIEW This article provides an in-depth analysis of the current research status of the MCU complex, focusing on its molecular composition, regulatory mechanisms, and association with diseases. In addition, we conducted an in-depth analysis of the regulatory effects of agonists, inhibitors, and traditional Chinese medicine (TCM) monomers on the MCU complex and their application prospects in disease treatment. From the perspective of medicinal chemistry, we conducted an in-depth analysis of the structure-activity relationship between these small molecules and MCU and deduced potential pharmacophores and binding pockets. Simultaneously, key structural domains of the MCU complex in Homo sapiens were identified. We also studied the functional expression of the MCU complex in Drosophila, Zebrafish, and Caenorhabditis elegans. These analyses provide a basis for exploring potential treatment strategies targeting the MCU complex and provide strong support for the development of future precision medicine and treatments. KEY SCIENTIFIC CONCEPTS OF REVIEW The MCU complex exhibits varying behavior across different tissues and plays various roles in metabolic functions. It consists of six MCU subunits, an essential MCU regulator (EMRE), and solute carrier 25A23 (SLC25A23). They regulate processes, such as mitochondrial Ca2+ (mCa2+) uptake, mitochondrial adenosine triphosphate (ATP) production, calcium dynamics, oxidative stress (OS), and cell death. Regulation makes it a potential target for treating diseases, especially cardiovascular diseases, neurodegenerative diseases, inflammatory diseases, metabolic diseases, and tumors.
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Affiliation(s)
- Jin Wang
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical College, University of South China, Hengyang 421001, China
| | - Jinyong Jiang
- Department of Pharmacy, The First Affiliated Hospital of Jishou University, Jishou 416000, China
| | - Haoliang Hu
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical College, University of South China, Hengyang 421001, China; College of Medicine, Hunan University of Arts and Science, Changde 415000, China.
| | - Linxi Chen
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical College, University of South China, Hengyang 421001, China.
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Borkar NA, Thompson MA, Bartman CM, Sathish V, Prakash YS, Pabelick CM. Nicotine affects mitochondrial structure and function in human airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2023; 325:L803-L818. [PMID: 37933473 PMCID: PMC11068407 DOI: 10.1152/ajplung.00158.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 09/26/2023] [Accepted: 10/24/2023] [Indexed: 11/08/2023] Open
Abstract
Exposure to cigarette smoke and e-cigarettes, with nicotine as the active constituent, contributes to increased health risks associated with asthma. Nicotine exerts its functional activity via nicotinic acetylcholine receptors (nAChRs), and the alpha7 subtype (α7nAChR) has recently been shown to adversely affect airway dynamics. The mechanisms of α7nAChR action in airways, particularly in the context of airway smooth muscle (ASM), a key cell type in asthma, are still under investigation. Mitochondria have garnered increasing interest for their role in regulating airway tone and adaptations to cellular stress. Here mitochondrial dynamics such as fusion versus fission, and mitochondrial Ca2+ ([Ca2+]m), play an important role in mitochondrial homeostasis. There is currently no information on effects and mechanisms by which nicotine regulates mitochondrial structure and function in ASM in the context of asthma. We hypothesized that nicotine disrupts mitochondrial morphology, fission-fusion balance, and [Ca2+]m regulation, with altered mitochondrial respiration and bioenergetics in the context of asthmatic ASM. Using human ASM (hASM) cells from nonasthmatics, asthmatics, and smokers, we examined the effects of nicotine on mitochondrial dynamics and [Ca2+]m. Fluorescence [Ca2+]m imaging of hASM cells with rhod-2 showed robust responses to 10 μM nicotine, particularly in asthmatics and smokers. In both asthmatics and smokers, nicotine increased the expression of fission proteins while decreasing fusion proteins. Seahorse analysis showed blunted oxidative phosphorylation parameters in response to nicotine in these groups. α7nAChR siRNA blunted nicotine effects, rescuing [Ca2+]m, changes in mitochondrial structural proteins, and mitochondrial dysfunction. These data highlight mitochondria as a target of nicotine effects on ASM, where mitochondrial disruption and impaired buffering could permit downstream effects of nicotine in the context of asthma.NEW & NOTEWORTHY Asthma is a major healthcare burden, which is further exacerbated by smoking. Recognizing the smoking risk of asthma, understanding the effects of nicotine on asthmatic airways becomes critical. Surprisingly, the mechanisms of nicotine action, even in normal and especially asthmatic airways, are understudied. Accordingly, the goal of this research is to investigate how nicotine influences asthmatic airways in terms of mitochondrial structure and function, via the a7nAChR.
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Affiliation(s)
- Niyati A Borkar
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Michael A Thompson
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Colleen M Bartman
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota, United States
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
| | - Christina M Pabelick
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
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Ramezani M, Wagenknecht-Wiesner A, Wang T, Holowka DA, Eliezer D, Baird BA. Alpha synuclein modulates mitochondrial Ca 2+ uptake from ER during cell stimulation and under stress conditions. NPJ Parkinsons Dis 2023; 9:137. [PMID: 37741841 PMCID: PMC10518018 DOI: 10.1038/s41531-023-00578-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 09/08/2023] [Indexed: 09/25/2023] Open
Abstract
Alpha synuclein (a-syn) is an intrinsically disordered protein prevalent in neurons, and aggregated forms are associated with synucleinopathies including Parkinson's disease (PD). Despite the biomedical importance and extensive studies, the physiological role of a-syn and its participation in etiology of PD remain uncertain. We showed previously in model RBL cells that a-syn colocalizes with mitochondrial membranes, depending on formation of N-terminal helices and increasing with mitochondrial stress1. We have now characterized this colocalization and functional correlates in RBL, HEK293, and N2a cells. We find that expression of a-syn enhances stimulated mitochondrial uptake of Ca2+ from the ER, depending on formation of its N-terminal helices but not on its disordered C-terminal tail. Our results are consistent with a-syn acting as a tether between mitochondria and ER, and we show increased contacts between these two organelles using structured illumination microscopy. We tested mitochondrial stress caused by toxins related to PD, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) and carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and found that a-syn prevents recovery of stimulated mitochondrial Ca2+ uptake. The C-terminal tail, and not N-terminal helices, is involved in this inhibitory activity, which is abrogated when phosphorylation site serine-129 is mutated (S129A). Correspondingly, we find that MPTP/MPP+ and CCCP stress is accompanied by both phosphorylation (pS129) and aggregation of a-syn. Overall, our results indicate that a-syn can participate as a tethering protein to modulate Ca2+ flux between ER and mitochondria, with potential physiological significance. A-syn can also prevent cellular recovery from toxin-induced mitochondrial dysfunction, which may represent a pathological role of a-syn in the etiology of PD.
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Affiliation(s)
- Meraj Ramezani
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | | | - Tong Wang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - David A Holowka
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA.
| | - Barbara A Baird
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA.
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5
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Ramezani M, Wagenknecht-Wiesner A, Wang T, Holowka DA, Eliezer D, Baird BA. Alpha Synuclein Modulates Mitochondrial Ca 2+ Uptake from ER During Cell Stimulation and Under Stress Conditions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.23.537965. [PMID: 37163091 PMCID: PMC10168219 DOI: 10.1101/2023.04.23.537965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Alpha synuclein (a-syn) is an intrinsically disordered protein prevalent in neurons, and aggregated forms are associated with synucleinopathies including Parkinson' disease (PD). Despite the biomedical importance and extensive studies, the physiological role of a-syn and its participation in etiology of PD remain uncertain. We showed previously in model RBL cells that a-syn colocalizes with mitochondrial membranes, depending on formation of N-terminal helices and increasing with mitochondrial stress. 1 We have now characterized this colocalization and functional correlates in RBL, HEK293, and N2a cells. We find that expression of a-syn enhances stimulated mitochondrial uptake of Ca 2+ from the ER, depending on formation of its N-terminal helices but not on its disordered C-terminal tail. Our results are consistent with a-syn acting as a tether between mitochondria and ER, and we show increased contacts between these two organelles using structured illumination microscopy. We tested mitochondrial stress caused by toxins related to PD, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) and carbonyl cyanide m-chlorophenyl hydrazone (CCCP), and found that a-syn prevents recovery of stimulated mitochondrial Ca 2+ uptake. The C-terminal tail, and not N-terminal helices, is involved in this inhibitory activity, which is abrogated when phosphorylation site serine-129 is mutated (S129A). Correspondingly, we find that MPTP/MPP+ and CCCP stress is accompanied by both phosphorylation (pS129) and aggregation of a-syn. Overall, our results indicate that a-syn can participate as a tethering protein to modulate Ca 2+ flux between ER and mitochondria, with potential physiological significance. A-syn can also prevent cellular recovery from toxin-induced mitochondrial dysfunction, which may represent a pathological role of a-syn in the etiology of PD.
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Affiliation(s)
- Meraj Ramezani
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | | | - Tong Wang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - David A. Holowka
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065
| | - Barbara A. Baird
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
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Patel A, Pietromicca JG, Venkatesan M, Maity S, Bard JE, Madesh M, Alevriadou BR. Modulation of the mitochondrial Ca 2+ uniporter complex subunit expression by different shear stress patterns in vascular endothelial cells. Physiol Rep 2023; 11:e15588. [PMID: 36754446 PMCID: PMC9908435 DOI: 10.14814/phy2.15588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/26/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023] Open
Abstract
Mitochondrial calcium (m Ca2+ ) uptake occurs via the Mitochondrial Ca2+ Uniporter (MCU) complex and plays a critical role in mitochondrial dynamics, mitophagy, and apoptosis. MCU complex activity is in part modulated by the expression of its regulatory subunits. Cardiovascular disease models demonstrated altered gene/protein expression of one or multiple subunits in different cells, including vascular endothelial cells (ECs). MCU complex activity was found necessary for stable flow (s-flow)-induced mitophagy and promotion of an atheroprotective EC phenotype. Disturbed flow (d-flow) is known to lead to an atheroprone phenotype. Despite the role of MCU in flow-regulated EC function, flow-induced alterations in MCU complex subunit expression are currently unknown. We exposed cultured human ECs to atheroprotective (steady shear stress, SS) or atheroprone flow (oscillatory shear stress, OS) and measured mRNA and protein levels of the MCU complex members. SS and OS differentially modulated subunit expression at gene/protein levels. Protein expression changes of the core MCU, m Ca2+ uptake 1 (MICU1) and MCU regulator 1 (MCUR1) subunits in SS- and OS-exposed, compared to static, ECs suggested an enhanced m Ca2+ influx under each flow and a potential contribution to EC dysfunction under OS. In silico analysis of a single-cell RNA-sequencing dataset was employed to extract transcript values of MCU subunits in mouse carotid ECs from regions exposed to s-flow or d-flow. Mcu and Mcur1 genes showed significant differences in expression after prolonged exposure to each flow. The differential expression of MCU complex subunits indicated a tight regulation of the complex activity under physiological and pathological hemodynamic conditions.
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Affiliation(s)
- Akshar Patel
- Vascular Mechanobiology Laboratory, Department of Biomedical Engineering, and Center for Cell, Gene, and Tissue EngineeringUniversity at Buffalo – The State University of New YorkBuffaloNew YorkUSA
| | - Julia G. Pietromicca
- Vascular Mechanobiology Laboratory, Department of Biomedical Engineering, and Center for Cell, Gene, and Tissue EngineeringUniversity at Buffalo – The State University of New YorkBuffaloNew YorkUSA
| | - Manigandan Venkatesan
- Department of Medicine, Center for Mitochondrial MedicineUniversity of Texas Health San AntonioSan AntonioTexasUSA
| | - Soumya Maity
- Department of Medicine, Center for Mitochondrial MedicineUniversity of Texas Health San AntonioSan AntonioTexasUSA
| | - Jonathan E. Bard
- Genomics and Bioinformatics Core, Jacobs School of Medicine and Biomedical SciencesUniversity at Buffalo – The State University of New YorkBuffaloNew YorkUSA
| | - Muniswamy Madesh
- Department of Medicine, Center for Mitochondrial MedicineUniversity of Texas Health San AntonioSan AntonioTexasUSA
| | - B. Rita Alevriadou
- Vascular Mechanobiology Laboratory, Department of Biomedical Engineering, and Center for Cell, Gene, and Tissue EngineeringUniversity at Buffalo – The State University of New YorkBuffaloNew YorkUSA
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7
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Colussi DM, Stathopulos PB. From passage to inhibition: Uncovering the structural and physiological inhibitory mechanisms of MCUb in mitochondrial calcium regulation. FASEB J 2023; 37:e22678. [PMID: 36538269 PMCID: PMC10107711 DOI: 10.1096/fj.202201080r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/14/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022]
Abstract
Mitochondrial calcium (Ca2+ ) regulation is critically implicated in the regulation of bioenergetics and cell fate. Ca2+ , a universal signaling ion, passively diffuses into the mitochondrial intermembrane space (IMS) through voltage-dependent anion channels (VDAC), where uptake into the matrix is tightly regulated across the inner mitochondrial membrane (IMM) by the mitochondrial Ca2+ uniporter complex (mtCU). In recent years, immense progress has been made in identifying and characterizing distinct structural and physiological mechanisms of mtCU component function. One of the main regulatory components of the Ca2+ selective mtCU channel is the mitochondrial Ca2+ uniporter dominant-negative beta subunit (MCUb). The structural mechanisms underlying the inhibitory effect(s) exerted by MCUb are poorly understood, despite high homology to the main mitochondrial Ca2+ uniporter (MCU) channel-forming subunits. In this review, we provide an overview of the structural differences between MCUb and MCU, believed to contribute to the inhibition of mitochondrial Ca2+ uptake. We highlight the possible structural rationale for the absent interaction between MCUb and the mitochondrial Ca2+ uptake 1 (MICU1) gatekeeping subunit and a potential widening of the pore upon integration of MCUb into the channel. We discuss physiological and pathophysiological information known about MCUb, underscoring implications in cardiac function and arrhythmia as a basis for future therapeutic discovery. Finally, we discuss potential post-translational modifications on MCUb as another layer of important regulation.
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Affiliation(s)
- Danielle M Colussi
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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8
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Patel A, Simkulet M, Maity S, Venkatesan M, Matzavinos A, Madesh M, Alevriadou BR. The mitochondrial Ca 2+ uniporter channel synergizes with fluid shear stress to induce mitochondrial Ca 2+ oscillations. Sci Rep 2022; 12:21161. [PMID: 36476944 PMCID: PMC9729216 DOI: 10.1038/s41598-022-25583-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
The mitochondrial calcium (Ca2+) uniporter (MCU) channel is responsible for mitochondrial Ca2+ influx. Its expression was found to be upregulated in endothelial cells (ECs) under cardiovascular disease conditions. Since the role of MCU in regulating cytosolic Ca2+ homeostasis in ECs exposed to shear stress (SS) is unknown, we studied mitochondrial Ca2+ dynamics (that is known to decode cytosolic Ca2+ signaling) in sheared ECs. To understand cause-and-effect, we ectopically expressed MCU in ECs. A higher percentage of MCU-transduced ECs exhibited mitochondrial Ca2+ transients/oscillations, and at higher frequency, under SS compared to sheared control ECs. Transients/oscillations correlated with mitochondrial reactive oxygen species (mROS) flashes and mitochondrial membrane potential (ΔΨm) flickers, and depended on activation of the mechanosensitive Piezo1 channel and the endothelial nitric oxide synthase (eNOS). A positive feedback loop composed of mitochondrial Ca2+ uptake/mROS flashes/ΔΨm flickers and endoplasmic reticulum Ca2+ release, in association with Piezo1 and eNOS, provided insights into the mechanism by which SS, under conditions of high MCU activity, may shape vascular EC energetics and function.
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Affiliation(s)
- Akshar Patel
- grid.273335.30000 0004 1936 9887Vascular Mechanobiology Laboratory, Department of Biomedical Engineering, and Center for Cell, Gene, and Tissue Engineering, University at Buffalo – The State University of New York, Buffalo, NY 14260 USA
| | - Matthew Simkulet
- grid.273335.30000 0004 1936 9887Vascular Mechanobiology Laboratory, Department of Biomedical Engineering, and Center for Cell, Gene, and Tissue Engineering, University at Buffalo – The State University of New York, Buffalo, NY 14260 USA
| | - Soumya Maity
- grid.267309.90000 0001 0629 5880Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229 USA
| | - Manigandan Venkatesan
- grid.267309.90000 0001 0629 5880Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229 USA
| | - Anastasios Matzavinos
- grid.7870.80000 0001 2157 0406Institute for Mathematical and Computational Engineering, Pontifical Catholic University of Chile, Santiago, Chile
| | - Muniswamy Madesh
- grid.267309.90000 0001 0629 5880Center for Mitochondrial Medicine, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229 USA
| | - B. Rita Alevriadou
- grid.273335.30000 0004 1936 9887Vascular Mechanobiology Laboratory, Department of Biomedical Engineering, and Center for Cell, Gene, and Tissue Engineering, University at Buffalo – The State University of New York, Buffalo, NY 14260 USA
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Costiniti V, Bomfim GHS, Neginskaya M, Son GY, Mitaishvili E, Giacomello M, Pavlov E, Lacruz RS. Mitochondria modulate ameloblast Ca 2+ signaling. FASEB J 2022; 36:e22169. [PMID: 35084775 PMCID: PMC8852362 DOI: 10.1096/fj.202100602r] [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: 06/02/2021] [Revised: 12/22/2021] [Accepted: 01/07/2022] [Indexed: 02/03/2023]
Abstract
The role of mitochondria in enamel, the most mineralized tissue in the body, is poorly defined. Enamel is formed by ameloblast cells in two main sequential stages known as secretory and maturation. Defining the physiological features of each stage is essential to understand mineralization. Here, we analyzed functional features of mitochondria in rat primary secretory and maturation-stage ameloblasts focusing on their role in Ca2+ signaling. Quantification of the Ca2+ stored in the mitochondria by trifluoromethoxy carbonylcyanide phenylhydrazone stimulation was comparable in both stages. The release of endoplasmic reticulum Ca2+ pools by adenosine triphosphate in rhod2AM-loaded cells showed similar mitochondrial Ca2+ (m Ca2+ ) uptake. However, m Ca2+ extrusion via Na+ -Li+ -Ca2+ exchanger was more prominent in maturation. To address if m Ca2+ uptake via the mitochondrial Ca2+ uniporter (MCU) played a role in cytosolic Ca2+ (c Ca2+ ) buffering, we stimulated Ca2+ influx via the store-operated Ca2+ entry (SOCE) and blocked MCU with the inhibitor Ru265. This inhibitor was first tested using the enamel cell line LS8 cells. Ru265 prevented c Ca2+ clearance in permeabilized LS8 cells like ruthenium red, and it did not affect ΔΨm in intact cells. In primary ameloblasts, SOCE stimulation elicited a significantly higher m Ca2+ uptake in maturation ameloblasts. The uptake of Ca2+ into the mitochondria was dramatically decreased in the presence of Ru265. Combined, these results suggest an increased mitochondrial Ca2+ handling in maturation but only upon stimulation of Ca2+ influx via SOCE. These functional studies provide insights not only on the role of mitochondria in ameloblast Ca2+ physiology, but also advance the concept that SOCE and m Ca2+ uptake are complementary processes in biological mineralization.
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Affiliation(s)
- Veronica Costiniti
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Guilherme H. S. Bomfim
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Maria Neginskaya
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Ga-Yeon Son
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Erna Mitaishvili
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Marta Giacomello
- Department of Biology, University of Padova, Padua, Italy,Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Evgeny Pavlov
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
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10
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Koh JH, Kim YW, Seo DY, Sohn TS. Mitochondrial TFAM as a Signaling Regulator between Cellular Organelles: A Perspective on Metabolic Diseases. Diabetes Metab J 2021; 45:853-865. [PMID: 34847642 PMCID: PMC8640147 DOI: 10.4093/dmj.2021.0138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/24/2021] [Indexed: 12/15/2022] Open
Abstract
Tissues actively involved in energy metabolism are more likely to face metabolic challenges from bioenergetic substrates and are susceptible to mitochondrial dysfunction, leading to metabolic diseases. The mitochondria receive signals regarding the metabolic states in cells and transmit them to the nucleus or endoplasmic reticulum (ER) using calcium (Ca2+) for appropriate responses. Overflux of Ca2+ in the mitochondria or dysregulation of the signaling to the nucleus and ER could increase the incidence of metabolic diseases including insulin resistance and type 2 diabetes mellitus. Mitochondrial transcription factor A (Tfam) may regulate Ca2+ flux via changing the mitochondrial membrane potential and signals to other organelles such as the nucleus and ER. Since Tfam is involved in metabolic function in the mitochondria, here, we discuss the contribution of Tfam in coordinating mitochondria-ER activities for Ca2+ flux and describe the mechanisms by which Tfam affects mitochondrial Ca2+ flux in response to metabolic challenges.
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Affiliation(s)
- Jin-Ho Koh
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
- Corresponding authors: Jin-Ho Koh https://orcid.org/0000-0003-4777-4399 Department of Physiology, Yeungnam University College of Medicine, 170 Hyeonchungro, Nam-gu, Daegu 42415, Korea E-mail:
| | - Yong-Woon Kim
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
| | - Dae-Yun Seo
- Cardiovascular and Metabolic Disease Center, Smart Marine Therapeutic Center, Department of Physiology, College of Medicine, Inje University, Busan, Korea
| | - Tae-Seo Sohn
- Department of Internal Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Tae-Seo Shon https://orcid.org/0000-0002-5135-3290 Department of Internal Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 271 Cheonbo-ro, Uijeongbu 11765, Korea E-mail:
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11
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Structural characterization of the mitochondrial Ca 2+ uniporter provides insights into Ca 2+ uptake and regulation. iScience 2021; 24:102895. [PMID: 34401674 PMCID: PMC8353469 DOI: 10.1016/j.isci.2021.102895] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The mitochondrial uniporter is a Ca2+-selective ion-conducting channel in the inner mitochondrial membrane that is involved in various cellular processes. The components of this uniporter, including the pore-forming membrane subunit MCU and the modulatory subunits MCUb, EMRE, MICU1, and MICU2, have been identified in recent years. Previously, extensive studies revealed various aspects of uniporter activities and proposed multiple regulatory models of mitochondrial Ca2+ uptake. Recently, the individual auxiliary components of the uniporter and its holocomplex have been structurally characterized, providing the first insight into the component structures and their spatial relationship within the context of the uniporter. Here, we review recent uniporter structural studies in an attempt to establish an architectural framework, elucidating the mechanism that governs mitochondrial Ca2+ uptake and regulation, and to address some apparent controversies. This information could facilitate further characterization of mitochondrial Ca2+ permeation and a better understanding of uniporter-related disease conditions. The uniporter contains multiple subunits regulating various cellular processes Significant structural progresses have been made for the holo-complex of uniporter The holo-complex structures have inspired to propose several regulatory models
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12
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Wang Y, Li X, Zhao F. MCU-Dependent mROS Generation Regulates Cell Metabolism and Cell Death Modulated by the AMPK/PGC-1α/SIRT3 Signaling Pathway. Front Med (Lausanne) 2021; 8:674986. [PMID: 34307407 PMCID: PMC8299052 DOI: 10.3389/fmed.2021.674986] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/14/2021] [Indexed: 11/13/2022] Open
Abstract
The mitochondrial calcium uniporter is an intensively investigated calcium channel, and its molecular components, structural features, and encoded genes have long been explored. Further studies have shown that the mitochondrial calcium unidirectional transporter (MCU) is a macromolecular complex related to intracellular and extracellular calcium regulation. Based on the current understanding, the MCU is crucial for maintaining cytosolic Ca2+ (cCa2+) homeostasis by modulating mitochondrial Ca2+ (mCa2+) uptake. The elevation of MCU-induced calcium levels is confirmed to be the main cause of mitochondrial reactive oxygen species (mROS) generation, which leads to disordered cellular metabolic patterns and cell death. In particular, in an I/R injury model, cancer cells, and adipocytes, MCU expression is maintained at high levels. As is well accepted, the AMPK/PGC-1α/SIRT3 pathway is believed to have an affinity for mROS formation and energy consumption. Therefore, we identified a link between MCU-related mROS formation and the AMPK/PGC-1α/SIRT3 signaling pathway in controlling cell metabolism and cell death, which may provide a new possibility of targeting the MCU to reverse relevant diseases.
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Affiliation(s)
- Yuxin Wang
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiang Li
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Fengchao Zhao
- Department of Orthopaedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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13
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Alevriadou BR, Patel A, Noble M, Ghosh S, Gohil VM, Stathopulos PB, Madesh M. Molecular nature and physiological role of the mitochondrial calcium uniporter channel. Am J Physiol Cell Physiol 2021; 320:C465-C482. [PMID: 33296287 PMCID: PMC8260355 DOI: 10.1152/ajpcell.00502.2020] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Calcium (Ca2+) signaling is critical for cell function and cell survival. Mitochondria play a major role in regulating the intracellular Ca2+ concentration ([Ca2+]i). Mitochondrial Ca2+ uptake is an important determinant of cell fate and governs respiration, mitophagy/autophagy, and the mitochondrial pathway of apoptosis. Mitochondrial Ca2+ uptake occurs via the mitochondrial Ca2+ uniporter (MCU) complex. This review summarizes the present knowledge on the function of MCU complex, regulation of MCU channel, and the role of MCU in Ca2+ homeostasis and human disease pathogenesis. The channel core consists of four MCU subunits and essential MCU regulators (EMRE). Regulatory proteins that interact with them include mitochondrial Ca2+ uptake 1/2 (MICU1/2), MCU dominant-negative β-subunit (MCUb), MCU regulator 1 (MCUR1), and solute carrier 25A23 (SLC25A23). In addition to these proteins, cardiolipin, a mitochondrial membrane-specific phospholipid, has been shown to interact with the channel core. The dynamic interplay between the core and regulatory proteins modulates MCU channel activity after sensing local changes in [Ca2+]i, reactive oxygen species, and other environmental factors. Here, we highlight the structural details of the human MCU heteromeric assemblies and their known roles in regulating mitochondrial Ca2+ homeostasis. MCU dysfunction has been shown to alter mitochondrial Ca2+ dynamics, in turn eliciting cell apoptosis. Changes in mitochondrial Ca2+ uptake have been implicated in pathological conditions affecting multiple organs, including the heart, skeletal muscle, and brain. However, our structural and functional knowledge of this vital protein complex remains incomplete, and understanding the precise role for MCU-mediated mitochondrial Ca2+ signaling in disease requires further research efforts.
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Affiliation(s)
- B Rita Alevriadou
- Department of Biomedical Engineering, Jacobs School of Medicine and Biomedical Sciences and School of Engineering and Applied Sciences, University at Buffalo-State University of New York, Buffalo, New York
| | - Akshar Patel
- Department of Biomedical Engineering, Jacobs School of Medicine and Biomedical Sciences and School of Engineering and Applied Sciences, University at Buffalo-State University of New York, Buffalo, New York
| | - Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Muniswamy Madesh
- Department of Medicine/Cardiology Division, Center for Precision Medicine, University of Texas Health San Antonio, San Antonio, Texas
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14
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Quezada ER, Díaz-Vegas A, Jaimovich E, Casas M. Changes in Gene Expression of the MCU Complex Are Induced by Electrical Stimulation in Adult Skeletal Muscle. Front Physiol 2021; 11:601313. [PMID: 33574764 PMCID: PMC7870689 DOI: 10.3389/fphys.2020.601313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/27/2020] [Indexed: 11/29/2022] Open
Abstract
The slow calcium transient triggered by low-frequency electrical stimulation (ES) in adult muscle fibers and regulated by the extracellular ATP/IP3/IP3R pathway has been related to muscle plasticity. A regulation of muscular tropism associated with the MCU has also been described. However, the role of transient cytosolic calcium signals and signaling pathways related to muscle plasticity over the regulation of gene expression of the MCU complex (MCU, MICU1, MICU2, and EMRE) in adult skeletal muscle is completely unknown. In the present work, we show that 270 0.3-ms-long pulses at 20-Hz ES (and not at 90 Hz) transiently decreased the mRNA levels of the MCU complex in mice flexor digitorum brevis isolated muscle fibers. Importantly, when ATP released after 20-Hz ES is hydrolyzed by the enzyme apyrase, the repressor effect of 20 Hz on mRNA levels of the MCU complex is lost. Accordingly, the exposure of muscle fibers to 30 μM exogenous ATP produces the same effect as 20-Hz ES. Moreover, the use of apyrase in resting conditions (without ES) increased mRNA levels of MCU, pointing out the importance of extracellular ATP concentration over MCU mRNA levels. The use of xestospongin B (inhibitor of IP3 receptors) also prevented the decrease of mRNA levels of MCU, MICU1, MICU2, and EMRE mediated by a low-frequency ES. Our results show that the MCU complex can be regulated by electrical stimuli in a frequency-dependent manner. The changes observed in mRNA levels may be related to changes in the mitochondria, associated with the phenotypic transition from a fast- to a slow-type muscle, according to the described effect of this stimulation frequency on muscle phenotype. The decrease in mRNA levels of the MCU complex by exogenous ATP and the increase in MCU levels when basal ATP is reduced with the enzyme apyrase indicate that extracellular ATP may be a regulator of the MCU complex. Moreover, our results suggest that this regulation is part of the axes linking low-frequency stimulation with ATP/IP3/IP3R.
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Affiliation(s)
- Esteban R Quezada
- Center for Exercise, Metabolism, and Cancer, Physiology and Biophysics Program, Biomedical Sciences Institute (ICBM), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Alexis Díaz-Vegas
- Center for Exercise, Metabolism, and Cancer, Physiology and Biophysics Program, Biomedical Sciences Institute (ICBM), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Enrique Jaimovich
- Center for Exercise, Metabolism, and Cancer, Physiology and Biophysics Program, Biomedical Sciences Institute (ICBM), Faculty of Medicine, University of Chile, Santiago, Chile
| | - Mariana Casas
- Center for Exercise, Metabolism, and Cancer, Physiology and Biophysics Program, Biomedical Sciences Institute (ICBM), Faculty of Medicine, University of Chile, Santiago, Chile
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15
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Katoshevski T, Ben-Kasus Nissim T, Sekler I. Recent studies on NCLX in health and diseases. Cell Calcium 2021; 94:102345. [PMID: 33508514 DOI: 10.1016/j.ceca.2020.102345] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/29/2020] [Accepted: 12/29/2020] [Indexed: 12/27/2022]
Abstract
The mitochondria is a major hub for cellular Ca 2+ signaling. The identification of MCU, the mitochondrial Ca 2+ influx mediator, and the mitochondrial Ca 2+ extruder NCLX, were major breakthroughs in this field. Their identification provided novel molecular tools and animal models to interrogate their physiological function and mode of regulation. Here we will focus on the mitochondrial Na + / Ca 2+ exchanger NCLX that plays a dual role in mitochondrial Na + and Ca 2+ signaling. We will discuss recent advances in NCLX mods of regulation by kinases and mitochondrial ΔΨ. We will also focus on the heterogeneity of its expression in distinct mitochondrial populations and the pathophysiological implication of its excessive degradation. We will describe the ongoing debate on the stoichiometry of Na + to Ca 2+ transport, mediated by NCLX, and its physiological implication. We will focus on the major effects of mitochondrial Na + signaling by NCLX on mitochondrial metabolism in health; and finally, we will discuss the role NCLX plays in a wide range of health disorders, from heart failure and cancer to Parkinson and Alzheimer disease, making it a prime candidate for therapeutic targeting.
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Affiliation(s)
- Tomer Katoshevski
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Tsipi Ben-Kasus Nissim
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Israel Sekler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
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16
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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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17
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Cassambai S, Mee CJ, Renshaw D, Hussain A. Tiotropium bromide, a long acting muscarinic receptor antagonist triggers intracellular calcium signalling in the heart. Toxicol Appl Pharmacol 2019; 384:114778. [DOI: 10.1016/j.taap.2019.114778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/14/2019] [Accepted: 10/06/2019] [Indexed: 12/30/2022]
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18
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Chapoy-Villanueva H, Silva-Platas C, Gutiérrez-Rodríguez AK, García N, Acuña-Morin E, Elizondo-Montemayor L, Oropeza-Almazán Y, Aguilar-Saenz A, García-Rivas G. Changes in the Stoichiometry of Uniplex Decrease Mitochondrial Calcium Overload and Contribute to Tolerance of Cardiac Ischemia/Reperfusion Injury in Hypothyroidism. Thyroid 2019; 29:1755-1764. [PMID: 31456501 PMCID: PMC6918869 DOI: 10.1089/thy.2018.0668] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background: Thyroid hormone status in hypothyroidism (HT) downregulates key elements in Ca2+ handling within the heart, reducing contractility, impairing the basal energetic balance, and increasing the risk of cardiovascular disease. Mitochondrial Ca2+ transport is reduced in HT, and tolerance to reperfusion damage has been documented, but the precise mechanism is not well understood. Therefore, we aimed to determine the stoichiometry and activity of the mitochondrial Ca2+ uniporter or uniplex in an HT model and the relevance to the opening of the mitochondrial permeability transition pores (mPTP) during ischemia/reperfusion (I/R) injury. Methods: An HT model was established in Wistar rats by treatment with 6-propylthiouracil for 28 days. Uniplex composition and activity were determined in cardiac mitochondria. Hearts were perfused ex vivo to induce I/R injury, and functional parameters related to contractility and tissue viability were evaluated. Results: The cardiac stoichiometry between two subunits of the uniplex (MICU1/MCU) increased by 25% in animals with HT. The intramitochondrial Ca2+ content was reduced by 40% and was less prone to the mPTP opening. After I/R injury, ischemic contracture and the onset of ventricular fibrillation were delayed in animals with HT, concomitant with a reduction in oxidative damage and mitochondrial dysfunction. Conclusions: Our results suggest that HT is associated with an increase in the cardiac MICU1/MCU ratio, thereby changing the stoichiometry between these subunits to increase the threshold to cytosolic Ca2+ and reduce mitochondrial Ca2+ overload. Our results also demonstrate that this HT model can be used to explore the role of mitochondrial Ca2+ transport in cardiac diseases due to its induced tolerance to cardiac damage.
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Affiliation(s)
- Héctor Chapoy-Villanueva
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
| | - Christian Silva-Platas
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
| | - Ana K. Gutiérrez-Rodríguez
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
| | - Noemí García
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
- Tecnologico de Monterrey, Hospital Zambrano Hellion, TecSalud, Centro de Investigación Biomédica, San Pedro Garza García, Mexico
| | - Edgar Acuña-Morin
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
| | - Leticia Elizondo-Montemayor
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
- Tecnologico de Monterrey, Hospital Zambrano Hellion, TecSalud, Centro de Investigación Biomédica, San Pedro Garza García, Mexico
| | - Yuriana Oropeza-Almazán
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
| | - Alejandro Aguilar-Saenz
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
| | - Gerardo García-Rivas
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Vascular, Monterrey, Mexico
- Tecnologico de Monterrey, Hospital Zambrano Hellion, TecSalud, Centro de Investigación Biomédica, San Pedro Garza García, Mexico
- Address correspondence to: Gerardo García-Rivas, PhD, Centro de Investigacion Biomedica, Hospital Zambrano-Hellion, Tecnologico de Monterrey, Edificio Escuela de Medicina. 2do. Nivel., Avenida Batallón de San Patricio 112, CP 66278 San Pedro Garza García, México
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19
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Roest G, La Rovere RM, Bultynck G, Parys JB. IP 3 Receptor Properties and Function at Membrane Contact Sites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 981:149-178. [PMID: 29594861 DOI: 10.1007/978-3-319-55858-5_7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a ubiquitously expressed Ca2+-release channel localized in the endoplasmic reticulum (ER). The intracellular Ca2+ signals originating from the activation of the IP3R regulate multiple cellular processes including the control of cell death versus cell survival via their action on apoptosis and autophagy. The exact role of the IP3Rs in these two processes does not only depend on their activity, which is modulated by the cytosolic composition (Ca2+, ATP, redox status, …) and by various types of regulatory proteins, including kinases and phosphatases as well as by a number of oncogenes and tumor suppressors, but also on their intracellular localization, especially at the ER-mitochondrial and ER-lysosomal interfaces. At these interfaces, Ca2+ microdomains are formed, in which the Ca2+ concentration is finely regulated by the different ER, mitochondrial and lysosomal Ca2+-transport systems and also depends on the functional and structural interactions existing between them. In this review, we therefore discuss the most recent insights in the role of Ca2+ signaling in general, and of the IP3R in particular, in the control of basal mitochondrial bioenergetics, apoptosis, and autophagy at the level of inter-organellar contact sites.
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Affiliation(s)
- Gemma Roest
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium
| | - Rita M La Rovere
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium
| | - Geert Bultynck
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium.
| | - Jan B Parys
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium.
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20
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Díaz-Vegas AR, Cordova A, Valladares D, Llanos P, Hidalgo C, Gherardi G, De Stefani D, Mammucari C, Rizzuto R, Contreras-Ferrat A, Jaimovich E. Mitochondrial Calcium Increase Induced by RyR1 and IP3R Channel Activation After Membrane Depolarization Regulates Skeletal Muscle Metabolism. Front Physiol 2018; 9:791. [PMID: 29988564 PMCID: PMC6026899 DOI: 10.3389/fphys.2018.00791] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/06/2018] [Indexed: 11/13/2022] Open
Abstract
Aim: We hypothesize that both type-1 ryanodine receptor (RyR1) and IP3-receptor (IP3R) calcium channels are necessary for the mitochondrial Ca2+ increase caused by membrane depolarization induced by potassium (or by electrical stimulation) of single skeletal muscle fibers; this calcium increase would couple muscle fiber excitation to an increase in metabolic output from mitochondria (excitation-metabolism coupling). Methods: Mitochondria matrix and cytoplasmic Ca2+ levels were evaluated in fibers isolated from flexor digitorium brevis muscle using plasmids for the expression of a mitochondrial Ca2+ sensor (CEPIA3mt) or a cytoplasmic Ca2+ sensor (RCaMP). The role of intracellular Ca2+ channels was evaluated using both specific pharmacological inhibitors (xestospongin B for IP3R and Dantrolene for RyR1) and a genetic approach (shIP3R1-RFP). O2 consumption was detected using Seahorse Extracellular Flux Analyzer. Results: In isolated muscle fibers cell membrane depolarization increased both cytoplasmic and mitochondrial Ca2+ levels. Mitochondrial Ca2+ uptake required functional inositol IP3R and RyR1 channels. Inhibition of either channel decreased basal O2 consumption rate but only RyR1 inhibition decreased ATP-linked O2 consumption. Cell membrane depolarization-induced Ca2+ signals in sub-sarcolemmal mitochondria were accompanied by a reduction in mitochondrial membrane potential; Ca2+ signals propagated toward intermyofibrillar mitochondria, which displayed increased membrane potential. These results are compatible with slow, Ca2+-dependent propagation of mitochondrial membrane potential from the surface toward the center of the fiber. Conclusion: Ca2+-dependent changes in mitochondrial membrane potential have different kinetics in the surface vs. the center of the fiber; these differences are likely to play a critical role in the control of mitochondrial metabolism, both at rest and after membrane depolarization as part of an “excitation-metabolism” coupling process in skeletal muscle fibers.
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Affiliation(s)
- Alexis R Díaz-Vegas
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Alex Cordova
- Biomedical Neuroscience Institute, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Denisse Valladares
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Exercise and Movement Science Laboratory, Universidad Finis Terrae, Santiago, Chile
| | - Paola Llanos
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Institute for Research in Dental Science, Universidad de Chile, Santiago, Chile
| | - Cecilia Hidalgo
- Biomedical Neuroscience Institute, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Gaia Gherardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ariel Contreras-Ferrat
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Enrique Jaimovich
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
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21
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Paupe V, Prudent J. New insights into the role of mitochondrial calcium homeostasis in cell migration. Biochem Biophys Res Commun 2018; 500:75-86. [PMID: 28495532 PMCID: PMC5930976 DOI: 10.1016/j.bbrc.2017.05.039] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 05/07/2017] [Indexed: 01/23/2023]
Abstract
Mitochondria are dynamic organelles involved in numerous physiological functions. Beyond their function in ATP production, mitochondria regulate cell death, reactive oxygen species (ROS) generation, immunity and metabolism. Mitochondria also play a key role in the buffering of cytosolic calcium, and calcium transported into the matrix regulates mitochondrial metabolism. Recently, the identification of the mitochondrial calcium uniporter (MCU) and associated regulators has allowed the characterization of new physiological roles for calcium in both mitochondrial and cellular homeostasis. Indeed, recent work has highlighted the importance of mitochondrial calcium homeostasis in regulating cell migration. Cell migration is a property common to all metazoans and is critical to embryogenesis, cancer progression, wound-healing and immune surveillance. Previous work has established that cytoplasmic calcium is a key regulator of cell migration, as oscillations in cytosolic calcium activate cytoskeletal remodelling, actin contraction and focal adhesion (FA) turnover necessary for cell movement. Recent work using animal models and in cellulo experiments to genetically modulate MCU and partners have shed new light on the role of mitochondrial calcium dynamics in cytoskeletal remodelling through the modulation of ATP and ROS production, as well as intracellular calcium signalling. This review focuses on MCU and its regulators in cell migration during physiological and pathophysiological processes including development and cancer. We also present hypotheses to explain the molecular mechanisms by which MCU may regulate mitochondrial dynamics and motility to drive cell migration.
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Affiliation(s)
- Vincent Paupe
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Julien Prudent
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, United Kingdom.
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22
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Bcl-2 inhibitors as anti-cancer therapeutics: The impact of and on calcium signaling. Cell Calcium 2018; 70:102-116. [DOI: 10.1016/j.ceca.2017.05.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/24/2017] [Accepted: 05/24/2017] [Indexed: 01/08/2023]
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23
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Arduino DM, Perocchi F. Pharmacological modulation of mitochondrial calcium homeostasis. J Physiol 2018; 596:2717-2733. [PMID: 29319185 DOI: 10.1113/jp274959] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/13/2017] [Indexed: 12/26/2022] Open
Abstract
Mitochondria are pivotal organelles in calcium (Ca2+ ) handling and signalling, constituting intracellular checkpoints for numerous processes that are vital for cell life. Alterations in mitochondrial Ca2+ homeostasis have been linked to a variety of pathological conditions and are critical in the aetiology of several human diseases. Efforts have been taken to harness mitochondrial Ca2+ transport mechanisms for therapeutic intervention, but pharmacological compounds that direct and selectively modulate mitochondrial Ca2+ homeostasis are currently lacking. New avenues have, however, emerged with the breakthrough discoveries on the genetic identification of the main players involved in mitochondrial Ca2+ influx and efflux pathways and with recent hints towards a deep understanding of the function of these molecular systems. Here, we review the current advances in the understanding of the mechanisms and regulation of mitochondrial Ca2+ homeostasis and its contribution to physiology and human disease. We also introduce and comment on the recent progress towards a systems-level pharmacological targeting of mitochondrial Ca2+ homeostasis.
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Affiliation(s)
- Daniela M Arduino
- Gene Center, Department of Biochemistry, Ludwig-Maximilians Universität München, Munich, 81377, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), Neuherberg, 85764, Germany
| | - Fabiana Perocchi
- Gene Center, Department of Biochemistry, Ludwig-Maximilians Universität München, Munich, 81377, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), Neuherberg, 85764, Germany
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24
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Ji SG, Weiss JH. Zn 2+-induced disruption of neuronal mitochondrial function: Synergism with Ca 2+, critical dependence upon cytosolic Zn 2+ buffering, and contributions to neuronal injury. Exp Neurol 2018; 302:181-195. [PMID: 29355498 DOI: 10.1016/j.expneurol.2018.01.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 12/15/2017] [Accepted: 01/15/2018] [Indexed: 10/18/2022]
Abstract
Excitotoxic Zn2+ and Ca2+ accumulation contributes to neuronal injury after ischemia or prolonged seizures. Synaptically released Zn2+ can enter postsynaptic neurons via routes including voltage sensitive Ca2+ channels (VSCC), and, more rapidly, through Ca2+ permeable AMPA channels. There are also intracellular Zn2+ binding proteins which can either buffer neuronal Zn2+ influx or release bound Zn2+ into the cytosol during pathologic conditions. Studies in culture highlight mitochondria as possible targets of Zn2+; cytosolic Zn2+ can enter mitochondria and induce effects including loss of mitochondrial membrane potential (ΔΨm), mitochondrial swelling, and reactive oxygen species (ROS) generation. While brief (5 min) neuronal depolarization (to activate VSCC) in the presence of 300 μM Zn2+ causes substantial delayed neurodegeneration, it only mildly impacts acute mitochondrial function, raising questions as to contributions of Zn2+-induced mitochondrial dysfunction to neuronal injury. Using brief high (90 mM) K+/Zn2+ exposures to mimic neuronal depolarization and extracellular Zn2+ accumulation as may accompany ischemia in vivo, we examined effects of disrupted cytosolic Zn2+ buffering and/or the presence of Ca2+, and made several observations: 1. Mild disruption of cytosolic Zn2+ buffering-while having little effects alone-markedly enhanced mitochondrial Zn2+ accumulation and dysfunction (including loss of ∆Ψm, ROS generation, swelling and respiratory inhibition) caused by relatively low (10-50 μM) Zn2+ with high K+. 2. The presence of Ca2+ during the Zn2+ exposure decreased cytosolic and mitochondrial Zn2+ accumulation, but markedly exacerbated the consequent dysfunction. 3. Paralleling effects on mitochondria, disruption of buffering and presence of Ca2+ enhanced Zn2+-induced neurodegeneration. 4. Zn2+ chelation after the high K+/Zn2+ exposure attenuated both ROS production and neurodegeneration, supporting the potential utility of delayed interventions. Taken together, these data lend credence to the idea that in pathologic states that impair cytosolic Zn2+ buffering, slow uptake of Zn2+ along with Ca2+ into neurons via VSCC can disrupt the mitochondria and induce neurodegeneration.
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Affiliation(s)
- Sung G Ji
- Department of Anatomy & Neurobiology, University of California, Irvine, USA
| | - John H Weiss
- Department of Anatomy & Neurobiology, University of California, Irvine, USA; Department of Neurology, University of California, Irvine, USA.
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25
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Sequential forward and reverse transport of the Na + Ca 2+ exchanger generates Ca 2+ oscillations within mitochondria. Nat Commun 2018; 9:156. [PMID: 29323106 PMCID: PMC5765001 DOI: 10.1038/s41467-017-02638-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 12/15/2017] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial Ca2+ homoeostasis regulates aerobic metabolism and cell survival. Ca2+ flux into mitochondria is mediated by the mitochondrial calcium uniporter (MCU) channel whereas Ca2+ export is often through an electrogenic Na+–Ca2+ exchanger. Here, we report remarkable functional versatility in mitochondrial Na+–Ca2+ exchange under conditions where mitochondria are depolarised. Following physiological stimulation of cell-surface receptors, mitochondrial Na+–Ca2+ exchange initially operates in reverse mode, transporting cytosolic Ca2+ into the matrix. As matrix Ca2+ rises, the exchanger reverts to its forward mode state, extruding Ca2+. Transitions between reverse and forward modes generate repetitive oscillations in matrix Ca2+. We further show that reverse mode Na+–Ca2+ activity is regulated by the mitochondrial fusion protein mitofusin 2. Our results demonstrate that reversible switching between transport modes of an ion exchanger molecule generates functionally relevant oscillations in the levels of the universal Ca2+ messenger within an organelle. Mitochondrial Ca2+ homoeostasis is tightly regulated and export of Ca2+ is mediated by an Na+Ca2+ exchanger. Here authors show that in depolarised mitochondria the exchanger initially operates in reverse mode, transporting cytosolic Ca2+ into the matrix before it reverts to its forward mode state.
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26
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Wacquier B, Romero Campos HE, González-Vélez V, Combettes L, Dupont G. Mitochondrial Ca2+dynamics in cells and suspensions. FEBS J 2017; 284:4128-4142. [DOI: 10.1111/febs.14296] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/17/2017] [Accepted: 10/17/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Benjamin Wacquier
- Unité de Chronobiologie Théorique; Université Libre de Bruxelles; Belgium
| | | | | | - Laurent Combettes
- Interactions Cellulaires et Physiopathologie Hépatique; UMR-S 1174; Université Paris Sud; Orsay France
| | - Geneviève Dupont
- Unité de Chronobiologie Théorique; Université Libre de Bruxelles; Belgium
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27
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Plattner H, Verkhratsky A. Inseparable tandem: evolution chooses ATP and Ca2+ to control life, death and cellular signalling. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0419. [PMID: 27377729 DOI: 10.1098/rstb.2015.0419] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 01/01/2023] Open
Abstract
From the very dawn of biological evolution, ATP was selected as a multipurpose energy-storing molecule. Metabolism of ATP required intracellular free Ca(2+) to be set at exceedingly low concentrations, which in turn provided the background for the role of Ca(2+) as a universal signalling molecule. The early-eukaryote life forms also evolved functional compartmentalization and vesicle trafficking, which used Ca(2+) as a universal signalling ion; similarly, Ca(2+) is needed for regulation of ciliary and flagellar beat, amoeboid movement, intracellular transport, as well as of numerous metabolic processes. Thus, during evolution, exploitation of atmospheric oxygen and increasingly efficient ATP production via oxidative phosphorylation by bacterial endosymbionts were a first step for the emergence of complex eukaryotic cells. Simultaneously, Ca(2+) started to be exploited for short-range signalling, despite restrictions by the preset phosphate-based energy metabolism, when both phosphates and Ca(2+) interfere with each other because of the low solubility of calcium phosphates. The need to keep cytosolic Ca(2+) low forced cells to restrict Ca(2+) signals in space and time and to develop energetically favourable Ca(2+) signalling and Ca(2+) microdomains. These steps in tandem dominated further evolution. The ATP molecule (often released by Ca(2+)-regulated exocytosis) rapidly grew to be the universal chemical messenger for intercellular communication; ATP effects are mediated by an extended family of purinoceptors often linked to Ca(2+) signalling. Similar to atmospheric oxygen, Ca(2+) must have been reverted from a deleterious agent to a most useful (intra- and extracellular) signalling molecule. Invention of intracellular trafficking further increased the role for Ca(2+) homeostasis that became critical for regulation of cell survival and cell death. Several mutually interdependent effects of Ca(2+) and ATP have been exploited in evolution, thus turning an originally unholy alliance into a fascinating success story.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Alexei Verkhratsky
- Faculty of Biological Sciences, University of Manchester, Manchester M13 9PT, UK Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
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28
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Calcium signaling and cell cycle: Progression or death. Cell Calcium 2017; 70:3-15. [PMID: 28801101 DOI: 10.1016/j.ceca.2017.07.006] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/23/2017] [Accepted: 07/23/2017] [Indexed: 12/12/2022]
Abstract
Cytosolic Ca2+ concentration levels fluctuate in an ordered manner along the cell cycle, in line with the fact that Ca2+ is involved in the regulation of cell proliferation. Cell proliferation should be an error-free process, yet is endangered by mistakes. In fact, a complex network of proteins ensures that cell cycle does not progress until the previous phase has been successfully completed. Occasionally, errors occur during the cell cycle leading to cell cycle arrest. If the error is severe, and the cell cycle checkpoints work perfectly, this results into cellular demise by activation of apoptotic or non-apoptotic cell death programs. Cancer is characterized by deregulated proliferation and resistance against cell death. Ca2+ is a central key to these phenomena as it modulates signaling pathways that control oncogenesis and cancer progression. Here, we discuss how Ca2+ participates in the exogenous and endogenous signals controlling cell proliferation, as well as in the mechanisms by which cells die if irreparable cell cycle damage occurs. Moreover, we summarize how Ca2+ homeostasis remodeling observed in cancer cells contributes to deregulated cell proliferation and resistance to cell death. Finally, we discuss the possibility to target specific components of Ca2+ signal pathways to obtain cytostatic or cytotoxic effects.
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29
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De Mario A, Peggion C, Massimino ML, Viviani F, Castellani A, Giacomello M, Lim D, Bertoli A, Sorgato MC. The prion protein regulates glutamate-mediated Ca 2+ entry and mitochondrial Ca 2+ accumulation in neurons. J Cell Sci 2017; 130:2736-2746. [PMID: 28701513 DOI: 10.1242/jcs.196972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 07/05/2017] [Indexed: 01/01/2023] Open
Abstract
The cellular prion protein (PrPC) whose conformational misfolding leads to the production of deadly prions, has a still-unclarified cellular function despite decades of intensive research. Following our recent finding that PrPC limits Ca2+ entry via store-operated Ca2+ channels in neurons, we investigated whether the protein could also control the activity of ionotropic glutamate receptors (iGluRs). To this end, we compared local Ca2+ movements in primary cerebellar granule neurons and cortical neurons transduced with genetically encoded Ca2+ probes and expressing, or not expressing, PrPC Our investigation demonstrated that PrPC downregulates Ca2+ entry through each specific agonist-stimulated iGluR and after stimulation by glutamate. We found that, although PrP-knockout (KO) mitochondria were displaced from the plasma membrane, glutamate addition resulted in a higher mitochondrial Ca2+ uptake in PrP-KO neurons than in their PrPC-expressing counterpart. This was because the increased Ca2+ entry through iGluRs in PrP-KO neurons led to a parallel increase in Ca2+-induced Ca2+ release via ryanodine receptor channels. These data thus suggest that PrPC takes part in the cell apparatus controlling Ca2+ homeostasis, and that PrPC is involved in protecting neurons from toxic Ca2+ overloads.
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Affiliation(s)
- Agnese De Mario
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Caterina Peggion
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Maria Lina Massimino
- CNR Neuroscience Institute, Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Francesca Viviani
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Angela Castellani
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Marta Giacomello
- Department of Biology, University of Padova, 35131 Padova, Italy
| | - Dmitry Lim
- Department of Pharmaceutical Science, University of Piemonte Orientale, 28100 Novara, Italy
| | - Alessandro Bertoli
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy
| | - Maria Catia Sorgato
- Department of Biomedical Science, University of Padova, 35131 Padova, Italy .,CNR Neuroscience Institute, Department of Biomedical Science, University of Padova, 35131 Padova, Italy
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30
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Devall M, Smith RG, Jeffries A, Hannon E, Davies MN, Schalkwyk L, Mill J, Weedon M, Lunnon K. Regional differences in mitochondrial DNA methylation in human post-mortem brain tissue. Clin Epigenetics 2017; 9:47. [PMID: 28473874 PMCID: PMC5415779 DOI: 10.1186/s13148-017-0337-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 03/30/2017] [Indexed: 12/22/2022] Open
Abstract
Background DNA methylation is an important epigenetic mechanism involved in gene regulation, with alterations in DNA methylation in the nuclear genome being linked to numerous complex diseases. Mitochondrial DNA methylation is a phenomenon that is receiving ever-increasing interest, particularly in diseases characterized by mitochondrial dysfunction; however, most studies have been limited to the investigation of specific target regions. Analyses spanning the entire mitochondrial genome have been limited, potentially due to the amount of input DNA required. Further, mitochondrial genetic studies have been previously confounded by nuclear-mitochondrial pseudogenes. Methylated DNA Immunoprecipitation Sequencing is a technique widely used to profile DNA methylation across the nuclear genome; however, reads mapped to mitochondrial DNA are often discarded. Here, we have developed an approach to control for nuclear-mitochondrial pseudogenes within Methylated DNA Immunoprecipitation Sequencing data. We highlight the utility of this approach in identifying differences in mitochondrial DNA methylation across regions of the human brain and pre-mortem blood. Results We were able to correlate mitochondrial DNA methylation patterns between the cortex, cerebellum and blood. We identified 74 nominally significant differentially methylated regions (p < 0.05) in the mitochondrial genome, between anatomically separate cortical regions and the cerebellum in matched samples (N = 3 matched donors). Further analysis identified eight significant differentially methylated regions between the total cortex and cerebellum after correcting for multiple testing. Using unsupervised hierarchical clustering analysis of the mitochondrial DNA methylome, we were able to identify tissue-specific patterns of mitochondrial DNA methylation between blood, cerebellum and cortex. Conclusions Our study represents a comprehensive analysis of the mitochondrial methylome using pre-existing Methylated DNA Immunoprecipitation Sequencing data to identify brain region-specific patterns of mitochondrial DNA methylation.
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Affiliation(s)
- Matthew Devall
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK
| | - Rebecca G Smith
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK
| | - Aaron Jeffries
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK.,Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, UK
| | - Eilis Hannon
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK
| | - Matthew N Davies
- Department of Twin Research & Genetic Epidemiology, King's College London, Lambeth Palace Road, London, UK
| | | | - Jonathan Mill
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK.,Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, UK
| | - Michael Weedon
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK
| | - Katie Lunnon
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK
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31
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Mitochondria Maintain Distinct Ca 2+ Pools in Cone Photoreceptors. J Neurosci 2017; 37:2061-2072. [PMID: 28115482 DOI: 10.1523/jneurosci.2689-16.2017] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 01/01/2023] Open
Abstract
Ca2+ ions have distinct roles in the outer segment, cell body, and synaptic terminal of photoreceptors. We tested the hypothesis that distinct Ca2+ domains are maintained by Ca2+ uptake into mitochondria. Serial block face scanning electron microscopy of zebrafish cones revealed that nearly 100 mitochondria cluster at the apical side of the inner segment, directly below the outer segment. The endoplasmic reticulum surrounds the basal and lateral surfaces of this cluster, but does not reach the apical surface or penetrate into the cluster. Using genetically encoded Ca2+ sensors, we found that mitochondria take up Ca2+ when it accumulates either in the cone cell body or outer segment. Blocking mitochondrial Ca2+ uniporter activity compromises the ability of mitochondria to maintain distinct Ca2+ domains. Together, our findings indicate that mitochondria can modulate subcellular functional specialization in photoreceptors.SIGNIFICANCE STATEMENT Ca2+ homeostasis is essential for the survival and function of retinal photoreceptors. Separate pools of Ca2+ regulate phototransduction in the outer segment, metabolism in the cell body, and neurotransmitter release at the synaptic terminal. We investigated the role of mitochondria in compartmentalization of Ca2+ We found that mitochondria form a dense cluster that acts as a diffusion barrier between the outer segment and cell body. The cluster is surprisingly only partially surrounded by the endoplasmic reticulum, a key mediator of mitochondrial Ca2+ uptake. Blocking the uptake of Ca2+ by mitochondria causes redistribution of Ca2+ throughout the cell. Our results show that mitochondrial Ca2+ uptake in photoreceptors is complex and plays an essential role in normal function.
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32
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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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33
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Soman S, Keatinge M, Moein M, Da Costa M, Mortiboys H, Skupin A, Sugunan S, Bazala M, Kuznicki J, Bandmann O. Inhibition of the mitochondrial calcium uniporter rescues dopaminergic neurons in pink1 -/- zebrafish. Eur J Neurosci 2016; 45:528-535. [PMID: 27859782 PMCID: PMC5324670 DOI: 10.1111/ejn.13473] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 11/03/2016] [Accepted: 11/04/2016] [Indexed: 11/26/2022]
Abstract
Mutations in PTEN-induced putative kinase 1 (PINK1) are a cause of early onset Parkinson's disease (PD). Loss of PINK1 function causes dysregulation of mitochondrial calcium homeostasis, resulting in mitochondrial dysfunction and neuronal cell death. We report that both genetic and pharmacological inactivation of the mitochondrial calcium uniporter (MCU), located in the inner mitochondrial membrane, prevents dopaminergic neuronal cell loss in pink1Y431 * mutant zebrafish (Danio rerio) via rescue of mitochondrial respiratory chain function. In contrast, genetic inactivation of the voltage dependent anion channel 1 (VDAC1), located in the outer mitochondrial membrane, did not rescue dopaminergic neurons in PINK1 deficient D. rerio. Subsequent gene expression studies revealed specific upregulation of the mcu regulator micu1 in pink1Y431 * mutant zebrafish larvae and inactivation of micu1 also results in rescue of dopaminergic neurons. The functional consequences of PINK1 deficiency and modified MCU activity were confirmed using a dynamic in silico model of Ca2+ triggered mitochondrial activity. Our data suggest modulation of MCU-mediated mitochondrial calcium homeostasis as a possible neuroprotective strategy in PINK1 mutant PD.
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Affiliation(s)
- Smijin Soman
- International Institute of Molecular and Cell Biology, Warsaw, Poland.,Bateson Centre, University of Sheffield, Sheffield, UK.,Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Marcus Keatinge
- Bateson Centre, University of Sheffield, Sheffield, UK.,Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Mahsa Moein
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Luxembourg, Luxembourg
| | - Marc Da Costa
- Bateson Centre, University of Sheffield, Sheffield, UK.,Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Heather Mortiboys
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Alexander Skupin
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Luxembourg, Luxembourg.,National Centre for Microscopy and Imaging Research, University of California San Diego, La Jolla, CA, USA
| | - Sreedevi Sugunan
- International Institute of Molecular and Cell Biology, Warsaw, Poland.,Bateson Centre, University of Sheffield, Sheffield, UK.,Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Michal Bazala
- International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Jacek Kuznicki
- International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Oliver Bandmann
- Bateson Centre, University of Sheffield, Sheffield, UK.,Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
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34
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Yan S, Du F, Wu L, Zhang Z, Zhong C, Yu Q, Wang Y, Lue LF, Walker DG, Douglas JT, Yan SS. F1F0 ATP Synthase-Cyclophilin D Interaction Contributes to Diabetes-Induced Synaptic Dysfunction and Cognitive Decline. Diabetes 2016; 65:3482-3494. [PMID: 27554467 PMCID: PMC5079631 DOI: 10.2337/db16-0556] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/09/2016] [Indexed: 02/03/2023]
Abstract
Mitochondrial abnormalities are well known to cause cognitive decline. However, the underlying molecular basis of mitochondria-associated neuronal and synaptic dysfunction in the diabetic brain remains unclear. Here, using a mitochondrial single-channel patch clamp and cyclophilin D (CypD)-deficient mice (Ppif -/-) with streptozotocin-induced diabetes, we observed an increase in the probability of Ca2+-induced mitochondrial permeability transition pore (mPTP) opening in brain mitochondria of diabetic mice, which was further confirmed by mitochondrial swelling and cytochrome c release induced by Ca2+ overload. Diabetes-induced elevation of CypD triggers enhancement of F1F0 ATP synthase-CypD interaction, which in turn leads to mPTP opening. Indeed, in patients with diabetes, brain cypD protein levels were increased. Notably, blockade of the F1F0 ATP synthase-CypD interaction by CypD ablation protected against diabetes-induced mPTP opening, ATP synthesis deficits, oxidative stress, and mitochondria dysfunction. Furthermore, the absence of CypD alleviated deficits in synaptic plasticity, learning, and memory in diabetic mice. Thus, blockade of ATP synthase interaction with CypD provides a promising new target for therapeutic intervention in diabetic encephalopathy.
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Affiliation(s)
- Shijun Yan
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Fang Du
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Long Wu
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Zhihua Zhang
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Changjia Zhong
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Qing Yu
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Yongfu Wang
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Lih-Fen Lue
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ
| | - Douglas G Walker
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ
| | - Justin T Douglas
- Nuclear Magnetic Resonance Laboratory, Molecular Structures Group, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Shirley ShiDu Yan
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
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35
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Abstract
Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations, e.g. magnesium. Its free concentration within cells can thus be maintained at the very low levels demanded by the signaling function. A large cadre of proteins has evolved to bind or transport calcium. They all contribute to buffer it within cells, but a number of them also decode its message for the benefit of the target. The most important of these "calcium sensors" are the EF-hand proteins. Calcium is an ambivalent messenger. Although essential to the correct functioning of cell processes, if not carefully controlled spatially and temporally within cells, it generates variously severe cell dysfunctions, and even cell death.
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Affiliation(s)
- Ernesto Carafoli
- From the Venetian Institute of Molecular Medicine, University of Padova, 35131 Padova, Italy and
| | - Joachim Krebs
- the Department of NMR Based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
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36
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Elustondo PA, Nichols M, Robertson GS, Pavlov EV. Mitochondrial Ca2+ uptake pathways. J Bioenerg Biomembr 2016; 49:113-119. [DOI: 10.1007/s10863-016-9676-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/05/2016] [Indexed: 12/19/2022]
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37
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Bhardwaj R, Hediger MA, Demaurex N. Redox modulation of STIM-ORAI signaling. Cell Calcium 2016; 60:142-52. [DOI: 10.1016/j.ceca.2016.03.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 03/08/2016] [Indexed: 12/14/2022]
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Liu JC, Liu J, Holmström KM, Menazza S, Parks RJ, Fergusson MM, Yu ZX, Springer DA, Halsey C, Liu C, Murphy E, Finkel T. MICU1 Serves as a Molecular Gatekeeper to Prevent In Vivo Mitochondrial Calcium Overload. Cell Rep 2016; 16:1561-1573. [PMID: 27477272 DOI: 10.1016/j.celrep.2016.07.011] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 03/24/2016] [Accepted: 07/03/2016] [Indexed: 01/10/2023] Open
Abstract
MICU1 is a component of the mitochondrial calcium uniporter, a multiprotein complex that also includes MICU2, MCU, and EMRE. Here, we describe a mouse model of MICU1 deficiency. MICU1(-/-) mitochondria demonstrate altered calcium uptake, and deletion of MICU1 results in significant, but not complete, perinatal mortality. Similar to afflicted patients, viable MICU1(-/-) mice manifest marked ataxia and muscle weakness. Early in life, these animals display a range of biochemical abnormalities, including increased resting mitochondrial calcium levels, altered mitochondrial morphology, and reduced ATP. Older MICU1(-/-) mice show marked, spontaneous improvement coincident with improved mitochondrial calcium handling and an age-dependent reduction in EMRE expression. Remarkably, deleting one allele of EMRE helps normalize calcium uptake while simultaneously rescuing the high perinatal mortality observed in young MICU1(-/-) mice. Together, these results demonstrate that MICU1 serves as a molecular gatekeeper preventing calcium overload and suggests that modulating the calcium uniporter could have widespread therapeutic benefits.
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Affiliation(s)
- Julia C Liu
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Jie Liu
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Kira M Holmström
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Sara Menazza
- Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Randi J Parks
- Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Maria M Fergusson
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Zu-Xi Yu
- Pathology Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Danielle A Springer
- Murine Phenotyping Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Charles Halsey
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Chengyu Liu
- Transgenic Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Elizabeth Murphy
- Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Toren Finkel
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA.
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39
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Jhun BS, Mishra J, Monaco S, Fu D, Jiang W, Sheu SS, O-Uchi J. The mitochondrial Ca2+ uniporter: regulation by auxiliary subunits and signal transduction pathways. Am J Physiol Cell Physiol 2016; 311:C67-80. [PMID: 27122161 DOI: 10.1152/ajpcell.00319.2015] [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] [Indexed: 01/14/2023]
Abstract
Mitochondrial Ca(2+) homeostasis, the Ca(2+) influx-efflux balance, is responsible for the control of numerous cellular functions, including energy metabolism, generation of reactive oxygen species, spatiotemporal dynamics of Ca(2+) signaling, and cell growth and death. Recent discovery of the molecular identity of the mitochondrial Ca(2+) uniporter (MCU) provides new possibilities for application of genetic approaches to study the mitochondrial Ca(2+) influx mechanism in various cell types and tissues. In addition, the subsequent discovery of various auxiliary subunits associated with MCU suggests that mitochondrial Ca(2+) uptake is not solely regulated by a single protein (MCU), but likely by a macromolecular protein complex, referred to as the MCU-protein complex (mtCUC). Moreover, recent reports have shown the potential role of MCU posttranslational modifications in the regulation of mitochondrial Ca(2+) uptake through mtCUC. These observations indicate that mtCUCs form a local signaling complex at the inner mitochondrial membrane that could significantly regulate mitochondrial Ca(2+) handling, as well as numerous mitochondrial and cellular functions. In this review we discuss the current literature on mitochondrial Ca(2+) uptake mechanisms, with a particular focus on the structure and function of mtCUC, as well as its regulation by signal transduction pathways, highlighting current controversies and discrepancies.
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Affiliation(s)
- Bong Sook Jhun
- Cardiovascular Research Center, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - Jyotsna Mishra
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Sarah Monaco
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Deming Fu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Wenmin Jiang
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jin O-Uchi
- Cardiovascular Research Center, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island; and
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40
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Tsai MF, Phillips CB, Ranaghan M, Tsai CW, Wu Y, Willliams C, Miller C. Dual functions of a small regulatory subunit in the mitochondrial calcium uniporter complex. eLife 2016; 5. [PMID: 27099988 PMCID: PMC4892889 DOI: 10.7554/elife.15545] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/19/2016] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial Ca2+ uptake, a process crucial for bioenergetics and Ca2+ signaling, is catalyzed by the mitochondrial calcium uniporter. The uniporter is a multi-subunit Ca2+-activated Ca2+ channel, with the Ca2+ pore formed by the MCU protein and Ca2+-dependent activation mediated by MICU subunits. Recently, a mitochondrial inner membrane protein EMRE was identified as a uniporter subunit absolutely required for Ca2+ permeation. However, the molecular mechanism and regulatory purpose of EMRE remain largely unexplored. Here, we determine the transmembrane orientation of EMRE, and show that its known MCU-activating function is mediated by the interaction of transmembrane helices from both proteins. We also reveal a second function of EMRE: to maintain tight MICU regulation of the MCU pore, a role that requires EMRE to bind MICU1 using its conserved C-terminal polyaspartate tail. This dual functionality of EMRE ensures that all transport-competent uniporters are tightly regulated, responding appropriately to a dynamic intracellular Ca2+ landscape. DOI:http://dx.doi.org/10.7554/eLife.15545.001 Like all power plants, mitochondria – the compartments inside our cells that supply energy – must adjust their energy output to match fluctuations in demand. Inside cells, the levels of calcium ions in the cytoplasm often signal such demands. Mitochondria therefore control their calcium ion levels with tightly regulated, membrane-embedded proteins that move calcium ions into and out of the mitochondria. One of these membrane machines, the mitochondrial calcium uniporter (MCU) complex, is a "smart channel" that admits calcium ions into the mitochondria only when their cytoplasmic levels exceed a threshold. The MCU complex contains four essential proteins: MCU, which forms the pore through which the calcium ions enter the mitochondrion; MICU1 and MICU2, which act as “gatekeepers”, opening the pore only when the cell contains high levels of calcium ions; and EMRE, a small, mysterious protein. Why is EMRE required for the channel's operation, and how does it fit into the four-protein complex? By comparing EMRE proteins from different species, constructing mutant forms of EMRE, and recording calcium ion transport in mitochondria from cultured human cells, Tsai, Phillips et al. show that EMRE has two key roles. First, it snuggles up against the MCU protein and forms an essential part of the calcium ion-selective pore. Second, it acts as molecular glue to fix the calcium ion-sensing MICU gatekeepers to the pore. These two linked functions ensure that the MCU complex switches on only when the cell contains high levels of calcium ions, preventing the cell becoming catastrophically overloaded with calcium ions and cell death. Challenges for the future are to purify the MCU complex and reconstitute its ability to transport calcium ions from its component parts. This will help to determine the structure of the channel. DOI:http://dx.doi.org/10.7554/eLife.15545.002
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Affiliation(s)
- Ming-Feng Tsai
- Department of Biochemistry, Brandeis University, Waltham, United States.,Howard Hughes Medical Institute, Brandeis University, Waltham, United States
| | - Charles B Phillips
- Department of Biochemistry, Brandeis University, Waltham, United States.,Howard Hughes Medical Institute, Brandeis University, Waltham, United States
| | - Matthew Ranaghan
- Department of Biochemistry, Brandeis University, Waltham, United States
| | - Chen-Wei Tsai
- Department of Biochemistry, Brandeis University, Waltham, United States.,Howard Hughes Medical Institute, Brandeis University, Waltham, United States
| | - Yujiao Wu
- Department of Biochemistry, Brandeis University, Waltham, United States.,Howard Hughes Medical Institute, Brandeis University, Waltham, United States
| | - Carole Willliams
- Department of Biochemistry, Brandeis University, Waltham, United States.,Howard Hughes Medical Institute, Brandeis University, Waltham, United States
| | - Christopher Miller
- Department of Biochemistry, Brandeis University, Waltham, United States.,Howard Hughes Medical Institute, Brandeis University, Waltham, United States
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41
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La Rovere RML, Roest G, Bultynck G, Parys JB. Intracellular Ca(2+) signaling and Ca(2+) microdomains in the control of cell survival, apoptosis and autophagy. Cell Calcium 2016; 60:74-87. [PMID: 27157108 DOI: 10.1016/j.ceca.2016.04.005] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 04/14/2016] [Accepted: 04/15/2016] [Indexed: 01/01/2023]
Abstract
The endoplasmic reticulum (ER), mitochondria and lysosomes are physically and/or functionally linked, establishing close contact sites between these organelles. As a consequence, Ca(2+) release events from the ER, the major intracellular Ca(2+)-storage organelle, have an immediate effect on the physiological function of mitochondria and lysosomes. Also, the lysosomes can act as a Ca(2+) source for Ca(2+) release into the cytosol, thereby influencing ER-based Ca(2+) signaling. Given the important role for mitochondria and lysosomes in cell survival, cell death and cell adaptation processes, it has become increasingly clear that Ca(2+) signals from or towards these organelles impact these processes. In this review, we discuss the most recent insights in the emerging role of Ca(2+) signaling in cellular survival by controlling basal mitochondrial bioenergetics and by regulating apoptosis, a mitochondrial process, and autophagy, a lysosomal process, in response to cell damage and cell stress.
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Affiliation(s)
- Rita M L La Rovere
- KU Leuven, Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, Campus Gasthuisberg O/N-1 B-802, BE-3000 Leuven, Belgium
| | - Gemma Roest
- KU Leuven, Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, Campus Gasthuisberg O/N-1 B-802, BE-3000 Leuven, Belgium
| | - Geert Bultynck
- KU Leuven, Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, Campus Gasthuisberg O/N-1 B-802, BE-3000 Leuven, Belgium.
| | - Jan B Parys
- KU Leuven, Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, Campus Gasthuisberg O/N-1 B-802, BE-3000 Leuven, Belgium.
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42
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Du J, Rountree A, Cleghorn WM, Contreras L, Lindsay KJ, Sadilek M, Gu H, Djukovic D, Raftery D, Satrústegui J, Kanow M, Chan L, Tsang SH, Sweet IR, Hurley JB. Phototransduction Influences Metabolic Flux and Nucleotide Metabolism in Mouse Retina. J Biol Chem 2015; 291:4698-710. [PMID: 26677218 DOI: 10.1074/jbc.m115.698985] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Indexed: 01/20/2023] Open
Abstract
Production of energy in a cell must keep pace with demand. Photoreceptors use ATP to maintain ion gradients in darkness, whereas in light they use it to support phototransduction. Matching production with consumption can be accomplished by coupling production directly to consumption. Alternatively, production can be set by a signal that anticipates demand. In this report we investigate the hypothesis that signaling through phototransduction controls production of energy in mouse retinas. We found that respiration in mouse retinas is not coupled tightly to ATP consumption. By analyzing metabolic flux in mouse retinas, we also found that phototransduction slows metabolic flux through glycolysis and through intermediates of the citric acid cycle. We also evaluated the relative contributions of regulation of the activities of α-ketoglutarate dehydrogenase and the aspartate-glutamate carrier 1. In addition, a comprehensive analysis of the retinal metabolome showed that phototransduction also influences steady-state concentrations of 5'-GMP, ribose-5-phosphate, ketone bodies, and purines.
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Affiliation(s)
- Jianhai Du
- From the Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | | | | | - Laura Contreras
- Department of Molecular Biology, Centre for Molecular Biology Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Científicas, CIBER of Rare Diseases (CIBERER), and Health Research Institute Jimenez Diaz Foundation, Autonomous University of Madrid, 28049 Madrid, Spain
| | | | | | - Haiwei Gu
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine
| | - Danijel Djukovic
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine
| | - Dan Raftery
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine
| | - Jorgina Satrústegui
- Department of Molecular Biology, Centre for Molecular Biology Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Científicas, CIBER of Rare Diseases (CIBERER), and Health Research Institute Jimenez Diaz Foundation, Autonomous University of Madrid, 28049 Madrid, Spain
| | | | - Lawrence Chan
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara and Donald Jonas Stem Cell Laboratory, Department of Ophthalmology, Columbia University, New York, New York, and
| | - Stephen H Tsang
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara and Donald Jonas Stem Cell Laboratory, Department of Ophthalmology, Columbia University, New York, New York, and Department of Pathology and Cell Biology and Institute of Human Nutrition, Columbia University, New York, New York 10032
| | | | - James B Hurley
- From the Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington 98109,
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43
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Furuno T, Shinkai N, Inoh Y, Nakanishi M. Impaired expression of the mitochondrial calcium uniporter suppresses mast cell degranulation. Mol Cell Biochem 2015; 410:215-21. [PMID: 26350567 DOI: 10.1007/s11010-015-2554-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/02/2015] [Indexed: 01/28/2023]
Abstract
Calcium ion (Ca(2+)) uptake into the mitochondrial matrix influences ATP production, Ca(2+) homeostasis, and apoptosis regulation. Ca(2+) uptake across the ion-impermeable inner mitochondrial membrane is mediated by the mitochondrial Ca(2+) uniporter (MCU) complex. The MCU complex forms a pore structure composed of several proteins. MCU is a Ca(2+)-selective channel in the inner-mitochondrial membrane that allows electrophoretic Ca(2+) entry into the matrix. Mitochondrial Ca(2+) uptake 1 (MICU1) functions as a Ca(2+)-sensing regulator of the MCU complex. Previously, by microscopic analysis at the single-cell level, we found that during mast cell activation, mitochondria capture cytosolic Ca(2+) in two steps. Consequently, mitochondrial Ca(2+) uptake likely plays a role in cellular function through cytosolic Ca(2+) buffering. Here, we investigate the role of MCU and MICU1 in mitochondrial Ca(2+) uptake and mast cell degranulation using MCU- and MICU1-knockdown (KD) mast cells. Whereas MCU- and MICU1-KD mast cells show normal proliferation rates and mitochondrial membrane potential, they exhibit slow and reduced cytosolic and mitochondrial Ca(2+) elevation after antigen stimulation. Moreover, β-hexosaminidase release induced by antigen was significantly suppressed in MCU-KD cells but not MICU1-KD cells. This suggests that both MCU and MICU1 are involved in mitochondrial Ca(2+) uptake in mast cells, while MCU plays a role in mast cell degranulation.
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Affiliation(s)
- Tadahide Furuno
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, 464-8650, Japan.
| | - Narumi Shinkai
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, 464-8650, Japan
| | - Yoshikazu Inoh
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, 464-8650, Japan
| | - Mamoru Nakanishi
- School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, 464-8650, Japan
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44
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Xu H, Martinoia E, Szabo I. Organellar channels and transporters. Cell Calcium 2015; 58:1-10. [PMID: 25795199 DOI: 10.1016/j.ceca.2015.02.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 12/22/2022]
Abstract
Decades of intensive research have led to the discovery of most plasma membrane ion channels and transporters and the characterization of their physiological functions. In contrast, although over 80% of transport processes occur inside the cells, the ion flux mechanisms across intracellular membranes (the endoplasmic reticulum, Golgi apparatus, endosomes, lysosomes, mitochondria, chloroplasts, and vacuoles) are difficult to investigate and remain poorly understood. Recent technical advances in super-resolution microscopy, organellar electrophysiology, organelle-targeted fluorescence imaging, and organelle proteomics have pushed a large step forward in the research of intracellular ion transport. Many new organellar channels are molecularly identified and electrophysiologically characterized. Additionally, molecular identification of many of these ion channels/transporters has made it possible to study their physiological functions by genetic and pharmacological means. For example, organellar channels have been shown to regulate important cellular processes such as programmed cell death and photosynthesis, and are involved in many different pathologies. This special issue (SI) on organellar channels and transporters aims to provide a forum to discuss the recent advances and to define the standard and open questions in this exciting and rapidly developing field. Along this line, a new Gordon Research Conference dedicated to the multidisciplinary study of intracellular membrane transport proteins will be launched this coming summer.
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Affiliation(s)
- Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University Avenue, Ann Arbor, MI 48109-1048, USA.
| | - Enrico Martinoia
- Institute of Plant Biology, University of Zürich, Zollikerstr. 107, CH-8008 Zürich, Switzerland.
| | - Ildiko Szabo
- Department of Biology, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy; CNR Neuroscience Institute, Viale G. Colombo 3, 35121 Padova, Italy.
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