101
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Mitochondrial hyperfusion: a friend or a foe. Biochem Soc Trans 2021; 48:631-644. [PMID: 32219382 DOI: 10.1042/bst20190987] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/24/2020] [Accepted: 03/04/2020] [Indexed: 12/13/2022]
Abstract
The cellular mitochondrial population undergoes repeated cycles of fission and fusion to maintain its integrity, as well as overall cellular homeostasis. While equilibrium usually exists between the fission-fusion dynamics, their rates are influenced by organellar and cellular metabolic and pathogenic conditions. Under conditions of cellular stress, there is a disruption of this fission and fusion balance and mitochondria undergo either increased fusion, forming a hyperfused meshwork or excessive fission to counteract stress and remove damaged mitochondria via mitophagy. While some previous reports suggest that hyperfusion is initiated to ameliorate cellular stress, recent studies show its negative impact on cellular health in disease conditions. The exact mechanism of mitochondrial hyperfusion and its role in maintaining cellular health and homeostasis, however, remain unclear. In this review, we aim to highlight the different aspects of mitochondrial hyperfusion in either promoting or mitigating stress and also its role in immunity and diseases.
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102
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Bai J, Liu C, Zhu P, Li Y. Novel Insights Into Molecular Mechanism of Mitochondria in Diabetic Cardiomyopathy. Front Physiol 2021; 11:609157. [PMID: 33536936 PMCID: PMC7849834 DOI: 10.3389/fphys.2020.609157] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/21/2020] [Indexed: 12/11/2022] Open
Abstract
Cardiovascular complication is one of the significant causes of death in diabetic mellitus (DM) in which diabetic cardiomyopathy, independent of hypertension, cardiac valvular disease, and coronary atherosclerosis, occupies an important position. Although the detailed pathogenesis of diabetic cardiomyopathy remains unclear currently, mitochondrial morphological abnormality and dysfunction were observed in diabetic cardiomyopathy animal models according to much research, suggesting that mitochondrial structural and functional impairment played an integral role in the formation of diabetic cardiomyopathy. Thus, we have summarized the effect of mitochondria on the process of diabetic cardiomyopathy, including abnormal mitochondrial morphology, mitochondrial energy metabolism disorder, enhanced mitochondrial oxidative stress, mitochondrial unbalanced calcium homeostasis, and mitochondrial autophagy. Based on the above mechanisms and the related evidence, more therapeutic strategies targeting mitochondria in diabetic cardiomyopathy have been and will be proposed to delay the progression of the disease.
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Affiliation(s)
- Jing Bai
- Medical School of Chinese PLA, Beijing, China.,Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Chuanbin Liu
- Medical School of Chinese PLA, Beijing, China.,Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Pingjun Zhu
- Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Yang Li
- Medical School of Chinese PLA, Beijing, China.,Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
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103
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Islam MN, Gusarova GA, Das SR, Li L, Monma E, Anjaneyulu M, Owusu-Ansah E, Bhattacharya S, Bhattacharya J. The Mitochondrial Calcium Uniporter of Pulmonary Type 2 Cells Determines Severity of ARDS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021. [PMID: 33469582 DOI: 10.1101/2021.01.18.427173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Acute lung immunity to inhaled pathogens elicits defensive pneumonitis that may convert to the Acute Respiratory Distress Syndrome (ARDS), causing high mortality. Mechanisms underlying the conversion are not understood, but are of intense interest because of the ARDS-induced mortality in the ongoing Covid-19 pandemic. Here, by optical imaging of live lungs we show that key to the lethality is the functional status of mitochondrial Ca2+ buffering across the mitochondrial Ca2+ uniporter (MCU) in the alveolar type 2 cells (AT2), which protect alveolar stability. In mice subjected to ARDS by airway exposure to lipopolysaccharide (LPS), or to Pseudomonas aeruginosa, there was marked loss of MCU expression in AT2. The ability of mice to survive ARDS depended on the extent to which the MCU expression recovered, indicating that the viability of Ca2+ buffering by AT2 mitochondria critically determines ARDS severity. Mitochondrial transfer to enhance AT2 MCU expression might protect against ARDS.
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104
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Indirubin-3'-monoxime induces paraptosis in MDA-MB-231 breast cancer cells by transmitting Ca 2+ from endoplasmic reticulum to mitochondria. Arch Biochem Biophys 2020; 698:108723. [PMID: 33321111 DOI: 10.1016/j.abb.2020.108723] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Indirubin-3'-monoxime (I3M) induces cell death in many cancer cells; however, whether I3M regulates paraptosis is unclear. The present study aimed to investigate I3M-induced paraptosis. METHODS We treated various cancer cells with I3M, and measured vacuole formation (a paraptosis marker) and the regulating signaling pathway such as endoplasmic reticulum (ER) stress, reactive oxygen species, and proteasomal dysfunction. RESULTS We found that I3M induced small vacuole formation in MDA-MB-231 breast cancer cells and transient knockdown of eIF2α and CHOP significantly downregulated vacuolation in the ER and mitochondria, as well as cell death in response to I3M, indicating that I3M-meditaed paraptosis was upregulated by ER stress. Moreover, I3M accumulated ubiquitinylated proteins via proteasome dysfunction, which stimulated ER stress-mediated Ca2+ release. A Ca2+ chelator significantly downregulated vacuolation in the ER and mitochondria as well as cell death, suggesting that Ca2+ was a key regulator in I3M-induced paraptosis. Our results also revealed that Ca2+ finally transited in mitochondria through mitochondrial Ca2+ uniporter (MCU), causing I3M-mediated paraptosis; however, the paraptosis was completely inhibited by, ruthenium red, an MCU inhibitor. CONCLUSION I3M induced proteasomal dysfunction-mediated ER stress and subsequently promoted Ca2+ release, which was accumulated in the mitochondria via MCU, thus causing paraptosis in MDA-MB-231 breast cancer cells.
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105
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Ryan KC, Ashkavand Z, Norman KR. The Role of Mitochondrial Calcium Homeostasis in Alzheimer's and Related Diseases. Int J Mol Sci 2020; 21:ijms21239153. [PMID: 33271784 PMCID: PMC7730848 DOI: 10.3390/ijms21239153] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023] Open
Abstract
Calcium signaling is essential for neuronal function, and its dysregulation has been implicated across neurodegenerative diseases, including Alzheimer’s disease (AD). A close reciprocal relationship exists between calcium signaling and mitochondrial function. Growing evidence in a variety of AD models indicates that calcium dyshomeostasis drastically alters mitochondrial activity which, in turn, drives neurodegeneration. This review discusses the potential pathogenic mechanisms by which calcium impairs mitochondrial function in AD, focusing on the impact of calcium in endoplasmic reticulum (ER)–mitochondrial communication, mitochondrial transport, oxidative stress, and protein homeostasis. This review also summarizes recent data that highlight the need for exploring the mechanisms underlying calcium-mediated mitochondrial dysfunction while suggesting potential targets for modulating mitochondrial calcium levels to treat neurodegenerative diseases such as AD.
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106
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Mechanisms of EMRE-Dependent MCU Opening in the Mitochondrial Calcium Uniporter Complex. Cell Rep 2020; 33:108486. [PMID: 33296646 PMCID: PMC7764451 DOI: 10.1016/j.celrep.2020.108486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/09/2020] [Accepted: 11/13/2020] [Indexed: 12/02/2022] Open
Abstract
The mitochondrial calcium uniporter is a multi-subunit Ca2+-activated Ca2+ channel, made up of the pore-forming MCU protein, a metazoan-specific EMRE subunit, and MICU1/MICU2, which mediate Ca2+ activation. It has been established that metazoan MCU requires EMRE binding to conduct Ca2+, but how EMRE promotes MCU opening remains unclear. Here, we demonstrate that EMRE controls MCU activity via its transmembrane helix, while using an N-terminal PKP motif to strengthen binding with MCU. Opening of MCU requires hydrophobic interactions mediated by MCU residues near the pore’s luminal end. Enhancing these interactions by single mutation allows human MCU to transport Ca2+ without EMRE. We further show that EMRE may facilitate MCU opening by stabilizing the open state in a conserved MCU gating mechanism, present also in non-metazoan MCU homologs. These results provide insights into the evolution of the uniporter machinery and elucidate the mechanism underlying the physiologically crucial EMRE-dependent MCU activation process. The mitochondrial calcium uniporter is a multi-subunit ion channel that imports cytoplasmic Ca2+ into mitochondria to regulate cell energy production and death. In this work, Van Keuren et al. report a key activation mechanism of the uniporter, mediated by an auxiliary EMRE subunit in the channel complex.
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107
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Seegren PV, Downs TK, Stremska ME, Harper LR, Cao R, Olson RJ, Upchurch CM, Doyle CA, Kennedy J, Stipes EL, Leitinger N, Periasamy A, Desai BN. Mitochondrial Ca 2+ Signaling Is an Electrometabolic Switch to Fuel Phagosome Killing. Cell Rep 2020; 33:108411. [PMID: 33238121 PMCID: PMC7793167 DOI: 10.1016/j.celrep.2020.108411] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 07/30/2020] [Accepted: 10/28/2020] [Indexed: 11/17/2022] Open
Abstract
Phagocytes reallocate metabolic resources to kill engulfed pathogens, but the intracellular signals that rapidly switch the immunometabolic program necessary to fuel microbial killing are not understood. We report that macrophages use a fast two-step Ca2+ relay to meet the bioenergetic demands of phagosomal killing. Upon detection of a fungal pathogen, macrophages rapidly elevate cytosolic Ca2+ (phase 1), and by concurrently activating the mitochondrial Ca2+ (mCa2+) uniporter (MCU), they trigger a rapid influx of Ca2+ into the mitochondria (phase 2). mCa2+ signaling reprograms mitochondrial metabolism, at least in part, through the activation of pyruvate dehydrogenase (PDH). Deprived of mCa2+ signaling, Mcu−/− macrophages are deficient in phagosomal reactive oxygen species (ROS) production and defective at killing fungi. Mice lacking MCU in their myeloid cells are highly susceptible to disseminated candidiasis. In essence, this study reveals an elegant design principle that MCU-dependent Ca2+ signaling is an electrometabolic switch to fuel phagosome killing. The signaling mechanisms that rapidly reallocate metabolic resources to meet the bioenergetic demands of microbial killing are not understood. Seegren et al. show that mitochondrial Ca2+ signaling serves as a fast electrometabolic switch to fuel microbial killing by phagocytes. This study identifies the mitochondrial Ca2+ channel MCU as a critical component of cell-intrinsic antimicrobial responses.
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Affiliation(s)
- Philip V Seegren
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA
| | - Taylor K Downs
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA
| | - Marta E Stremska
- Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA; Microbiology, Immunology, and Cancer Biology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Logan R Harper
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Ruofan Cao
- The W.M. Keck Center for Cellular Imaging, University of Virginia, Physical and Life Sciences Building (PLSB), 90 Geldard Drive, Charlottesville, VA 22904, USA; Departments of Biology, University of Virginia, Physical and Life Sciences Building (PLSB), 90 Geldard Drive, Charlottesville, VA 22904, USA
| | - Rachel J Olson
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Clint M Upchurch
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA
| | - Catherine A Doyle
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA
| | - Joel Kennedy
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Eric L Stipes
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Norbert Leitinger
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA
| | - Ammasi Periasamy
- The W.M. Keck Center for Cellular Imaging, University of Virginia, Physical and Life Sciences Building (PLSB), 90 Geldard Drive, Charlottesville, VA 22904, USA; Departments of Biology, University of Virginia, Physical and Life Sciences Building (PLSB), 90 Geldard Drive, Charlottesville, VA 22904, USA
| | - Bimal N Desai
- Pharmacology Department, University of Virginia, Pinn Hall, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Carter Immunology Center, University of Virginia, 345 Crispell r. MR-6, Charlottesville, VA 22908, USA.
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108
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Various Aspects of Calcium Signaling in the Regulation of Apoptosis, Autophagy, Cell Proliferation, and Cancer. Int J Mol Sci 2020; 21:ijms21218323. [PMID: 33171939 PMCID: PMC7664196 DOI: 10.3390/ijms21218323] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/28/2020] [Accepted: 11/03/2020] [Indexed: 12/11/2022] Open
Abstract
Calcium (Ca2+) is a major second messenger in cells and is essential for the fate and survival of all higher organisms. Different Ca2+ channels, pumps, or exchangers regulate variations in the duration and levels of intracellular Ca2+, which may be transient or sustained. These changes are then decoded by an elaborate toolkit of Ca2+-sensors, which translate Ca2+ signal to intracellular operational cell machinery, thereby regulating numerous Ca2+-dependent physiological processes. Alterations to Ca2+ homoeostasis and signaling are often deleterious and are associated with certain pathological states, including cancer. Altered Ca2+ transmission has been implicated in a variety of processes fundamental for the uncontrolled proliferation and invasiveness of tumor cells and other processes important for cancer progression, such as the development of resistance to cancer therapies. Here, we review what is known about Ca2+ signaling and how this fundamental second messenger regulates life and death decisions in the context of cancer, with particular attention directed to cell proliferation, apoptosis, and autophagy. We also explore the intersections of Ca2+ and the therapeutic targeting of cancer cells, summarizing the therapeutic opportunities for Ca2+ signal modulators to improve the effectiveness of current anticancer therapies.
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109
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Perkins G, Lee JH, Park S, Kang M, Perez-Flores MC, Ju S, Phillips G, Lysakowski A, Gratton MA, Yamoah EN. Altered Outer Hair Cell Mitochondrial and Subsurface Cisternae Connectomics Are Candidate Mechanisms for Hearing Loss in Mice. J Neurosci 2020; 40:8556-8572. [PMID: 33020216 PMCID: PMC7605424 DOI: 10.1523/jneurosci.2901-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 11/21/2022] Open
Abstract
Organelle crosstalk is vital for cellular functions. The propinquity of mitochondria, ER, and plasma membrane promote regulation of multiple functions, which include intracellular Ca2+ flux, and cellular biogenesis. Although the purposes of apposing mitochondria and ER have been described, an understanding of altered organelle connectomics related to disease states is emerging. Since inner ear outer hair cell (OHC) degeneration is a common trait of age-related hearing loss, the objective of this study was to investigate whether the structural and functional coupling of mitochondria with subsurface cisternae (SSC) was affected by aging. We applied functional and structural probes to equal numbers of male and female mice with a hearing phenotype akin to human aging. We discovered the polarization of cristae and crista junctions in mitochondria tethered to the SSC in OHCs. Aging was associated with SSC stress and decoupling of mitochondria with the SSC, mitochondrial fission/fusion imbalance, a remarkable reduction in mitochondrial and cytoplasmic Ca2+ levels, reduced K+-induced Ca2+ uptake, and marked plasticity of cristae membranes. A model of structure-based ATP production predicts profound energy stress in older OHCs. This report provides data suggesting that altered membrane organelle connectomics may result in progressive hearing loss.
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Affiliation(s)
- Guy Perkins
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, California 92093
| | | | | | | | | | - Saeyeon Ju
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, California 92093
| | - Grady Phillips
- Washington University School of Medicine, St. Louis, Missouri 63110
| | - Anna Lysakowski
- Departments of Anatomy and Cell Biology and Otolaryngology, University of Illinois at Chicago, Chicago, Illinois 60612
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110
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MacEwen MJ, Markhard AL, Bozbeyoglu M, Bradford F, Goldberger O, Mootha VK, Sancak Y. Evolutionary divergence reveals the molecular basis of EMRE dependence of the human MCU. Life Sci Alliance 2020; 3:e202000718. [PMID: 32769116 PMCID: PMC7425227 DOI: 10.26508/lsa.202000718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 01/18/2023] Open
Abstract
The mitochondrial calcium uniporter (MCU) is a calcium-activated calcium channel critical for signaling and bioenergetics. MCU, the pore-forming subunit of the uniporter, contains two transmembrane domains and is found in all major eukaryotic taxa. In amoeba and fungi, MCU homologs are sufficient to form a functional calcium channel, whereas human MCU exhibits a strict requirement for the metazoan protein essential MCU regulator (EMRE) for conductance. Here, we exploit this evolutionary divergence to decipher the molecular basis of human MCU's dependence on EMRE. By systematically generating chimeric proteins that consist of EMRE-independent Dictyostelium discoideum MCU and Homo sapiens MCU (HsMCU), we converged on a stretch of 10 amino acids in D. discoideum MCU that can be transplanted to HsMCU to render it EMRE independent. We call this region in human MCU the EMRE dependence domain (EDD). Crosslinking experiments show that EMRE directly interacts with HsMCU at its transmembrane domains as well as the EDD. Our results suggest that EMRE stabilizes the EDD of MCU, permitting both channel opening and calcium conductance, consistent with recently published structures of MCU-EMRE.
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Affiliation(s)
| | - Andrew L Markhard
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Mert Bozbeyoglu
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Forrest Bradford
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Olga Goldberger
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Broad Institute, Cambridge, MA, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Yasemin Sancak
- Department of Pharmacology, University of Washington, Seattle, WA, USA
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111
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Mitochondrial Calcium Deregulation in the Mechanism of Beta-Amyloid and Tau Pathology. Cells 2020; 9:cells9092135. [PMID: 32967303 PMCID: PMC7564294 DOI: 10.3390/cells9092135] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 02/06/2023] Open
Abstract
Aggregation and deposition of β-amyloid and/or tau protein are the key neuropathological features in neurodegenerative disorders such as Alzheimer's disease (AD) and other tauopathies including frontotemporal dementia (FTD). The interaction between oxidative stress, mitochondrial dysfunction and the impairment of calcium ions (Ca2+) homeostasis induced by misfolded tau and β-amyloid plays an important role in the progressive neuronal loss occurring in specific areas of the brain. In addition to the control of bioenergetics and ROS production, mitochondria are fine regulators of the cytosolic Ca2+ homeostasis that induce vital signalling mechanisms in excitable cells such as neurons. Impairment in the mitochondrial Ca2+ uptake through the mitochondrial Ca2+ uniporter (MCU) or release through the Na+/Ca2+ exchanger may lead to mitochondrial Ca2+ overload and opening of the permeability transition pore inducing neuronal death. Recent evidence suggests an important role for these mechanisms as the underlying causes for neuronal death in β-amyloid and tau pathology. The present review will focus on the mechanisms that lead to cytosolic and especially mitochondrial Ca2+ disturbances occurring in AD and tau-induced FTD, and propose possible therapeutic interventions for these disorders.
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112
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Wang C, Baradaran R, Long SB. Structure and Reconstitution of an MCU-EMRE Mitochondrial Ca 2+ Uniporter Complex. J Mol Biol 2020; 432:5632-5648. [PMID: 32841658 PMCID: PMC7577567 DOI: 10.1016/j.jmb.2020.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/15/2020] [Accepted: 08/18/2020] [Indexed: 10/23/2022]
Abstract
The proteins MCU and EMRE form the minimal functional unit of the mitochondrial calcium uniporter complex in metazoans, a highly selective and tightly controlled Ca2+ channel of the inner mitochondrial membrane that regulates cellular metabolism. Here we present functional reconstitution of an MCU-EMRE complex from the red flour beetle, Tribolium castaneum, and a cryo-EM structure of the complex at 3.5 Å resolution. Using a novel assay, we demonstrate robust Ca2+ uptake into proteoliposomes containing the purified complex. Uptake is dependent on EMRE and also on the mitochondrial lipid cardiolipin. The structure reveals a tetrameric channel with a single ion pore. EMRE is located at the periphery of the transmembrane domain and associates primarily with the first transmembrane helix of MCU. Coiled-coil and juxtamembrane domains within the matrix portion of the complex adopt markedly different conformations than in a structure of a human MCU-EMRE complex, suggesting that the structures represent different conformations of these functionally similar metazoan channels.
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Affiliation(s)
- Chongyuan Wang
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Rozbeh Baradaran
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Stephen Barstow Long
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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113
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Marchi S, Giorgi C, Galluzzi L, Pinton P. Ca 2+ Fluxes and Cancer. Mol Cell 2020; 78:1055-1069. [PMID: 32559424 DOI: 10.1016/j.molcel.2020.04.017] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 02/06/2023]
Abstract
Ca2+ ions are key second messengers in both excitable and non-excitable cells. Owing to the rather pleiotropic nature of Ca2+ transporters and other Ca2+-binding proteins, however, Ca2+ signaling has attracted limited attention as a potential target of anticancer therapy. Here, we discuss cancer-associated alterations of Ca2+ fluxes at specific organelles as we identify novel candidates for the development of drugs that selectively target Ca2+ signaling in malignant cells.
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Affiliation(s)
- Saverio Marchi
- Department of Clinical and Molecular Sciences, Marche Polytechnic University, Ancona, Italy
| | - Carlotta Giorgi
- Department of Medical Sciences, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA; Sandra and Edward Meyer Cancer Center, New York, NY, USA; Caryl and Israel Englander Institute for Precision Medicine, New York, NY, USA; Department of Dermatology, Yale School of Medicine, New Haven, CT, USA; Université de Paris, Paris, France.
| | - Paolo Pinton
- Department of Medical Sciences, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
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114
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Boyman L, Lederer WJ. How the mitochondrial calcium uniporter complex (MCU cx) works. Proc Natl Acad Sci U S A 2020; 117:22634-22636. [PMID: 32879002 PMCID: PMC7502774 DOI: 10.1073/pnas.2015886117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201;
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201
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115
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Zampese E, Surmeier DJ. Calcium, Bioenergetics, and Parkinson's Disease. Cells 2020; 9:cells9092045. [PMID: 32911641 PMCID: PMC7564460 DOI: 10.3390/cells9092045] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
Degeneration of substantia nigra (SN) dopaminergic (DAergic) neurons is responsible for the core motor deficits of Parkinson’s disease (PD). These neurons are autonomous pacemakers that have large cytosolic Ca2+ oscillations that have been linked to basal mitochondrial oxidant stress and turnover. This review explores the origin of Ca2+ oscillations and their role in the control of mitochondrial respiration, bioenergetics, and mitochondrial oxidant stress.
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116
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Thévenod F, Lee WK, Garrick MD. Iron and Cadmium Entry Into Renal Mitochondria: Physiological and Toxicological Implications. Front Cell Dev Biol 2020; 8:848. [PMID: 32984336 PMCID: PMC7492674 DOI: 10.3389/fcell.2020.00848] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/07/2020] [Indexed: 12/15/2022] Open
Abstract
Regulation of body fluid homeostasis is a major renal function, occurring largely through epithelial solute transport in various nephron segments driven by Na+/K+-ATPase activity. Energy demands are greatest in the proximal tubule and thick ascending limb where mitochondrial ATP production occurs through oxidative phosphorylation. Mitochondria contain 20-80% of the cell's iron, copper, and manganese that are imported for their redox properties, primarily for electron transport. Redox reactions, however, also lead to reactive, toxic compounds, hence careful control of redox-active metal import into mitochondria is necessary. Current dogma claims the outer mitochondrial membrane (OMM) is freely permeable to metal ions, while the inner mitochondrial membrane (IMM) is selectively permeable. Yet we recently showed iron and manganese import at the OMM involves divalent metal transporter 1 (DMT1), an H+-coupled metal ion transporter. Thus, iron import is not only regulated by IMM mitoferrins, but also depends on the OMM to intermembrane space H+ gradient. We discuss how these mitochondrial transport processes contribute to renal injury in systemic (e.g., hemochromatosis) and local (e.g., hemoglobinuria) iron overload. Furthermore, the environmental toxicant cadmium selectively damages kidney mitochondria by "ionic mimicry" utilizing iron and calcium transporters, such as OMM DMT1 or IMM calcium uniporter, and by disrupting the electron transport chain. Consequently, unraveling mitochondrial metal ion transport may help develop new strategies to prevent kidney injury induced by metals.
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Affiliation(s)
- Frank Thévenod
- Faculty of Health, Centre for Biomedical Education and Research, Institute of Physiology, Pathophysiology and Toxicology, Witten/Herdecke University, Witten, Germany
| | - Wing-Kee Lee
- Faculty of Health, Centre for Biomedical Education and Research, Institute of Physiology, Pathophysiology and Toxicology, Witten/Herdecke University, Witten, Germany
| | - Michael D Garrick
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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117
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Brown JA, Sammy MJ, Ballinger SW. An evolutionary, or "Mitocentric" perspective on cellular function and disease. Redox Biol 2020; 36:101568. [PMID: 32512469 PMCID: PMC7281786 DOI: 10.1016/j.redox.2020.101568] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/01/2020] [Accepted: 05/05/2020] [Indexed: 12/11/2022] Open
Abstract
The incidence of common, metabolic diseases (e.g. obesity, cardiovascular disease, diabetes) with complex genetic etiology has been steadily increasing nationally and globally. While identification of a genetic model that explains susceptibility and risk for these diseases has been pursued over several decades, no clear paradigm has yet been found to disentangle the genetic basis of polygenic/complex disease development. Since the evolution of the eukaryotic cell involved a symbiotic interaction between the antecedents of the mitochondrion and nucleus (which itself is a genetic hybrid), we suggest that this history provides a rational basis for investigating whether genetic interaction and co-evolution of these genomes still exists. We propose that both mitochondrial and Mendelian, or "mito-Mendelian" genetics play a significant role in cell function, and thus disease risk. This paradigm contemplates the natural variation and co-evolution of both mitochondrial and nuclear DNA backgrounds on multiple mitochondrial functions that are discussed herein, including energy production, cell signaling and immune response, which collectively can influence disease development. At the nexus of these processes is the economy of mitochondrial metabolism, programmed by both mitochondrial and nuclear genomes.
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Affiliation(s)
- Jamelle A Brown
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Melissa J Sammy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Scott W Ballinger
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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118
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Roy Chowdhury A, Srinivasan S, Csordás G, Hajnóczky G, Avadhani NG. Dysregulation of RyR Calcium Channel Causes the Onset of Mitochondrial Retrograde Signaling. iScience 2020; 23:101370. [PMID: 32738613 PMCID: PMC7394923 DOI: 10.1016/j.isci.2020.101370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 02/18/2020] [Accepted: 07/13/2020] [Indexed: 01/22/2023] Open
Abstract
This study shows that multiple modes of mitochondrial stress generated by partial mtDNA depletion or cytochrome c oxidase disruption cause ryanodine receptor channel (RyR) dysregulation, which instigates the release of Ca2+ in the cytoplasm of C2C12 myoblasts and HCT116 carcinoma cells. We also observed a reciprocal downregulation of IP3R channel activity and reduced mitochondrial uptake of Ca2+. Ryanodine, an RyR antagonist, abrogated the mitochondrial stress-mediated increase in [Ca2+]c and the entire downstream signaling cascades of mitochondrial retrograde signaling. Interestingly, ryanodine also inhibited mitochondrial stress-induced invasive behavior in mtDNA-depleted C2C12 cells and HCT116 carcinoma cells. In addition, co-immunoprecipitation shows reduced FKBP12 protein binding to RyR channel proteins, suggesting the altered function of the Ca2+ channel. These results document how the endoplasmic reticulum-associated RyR channels, in combination with inhibition of the mitochondrial uniporter system, modulate cellular Ca2+ homeostasis and signaling under mitochondrial stress conditions.
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Affiliation(s)
- Anindya Roy Chowdhury
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Satish Srinivasan
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - György Csordás
- Mitocare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - György Hajnóczky
- Mitocare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Narayan G Avadhani
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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119
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Wu W, Shen Q, Zhang R, Qiu Z, Wang Y, Zheng J, Jia Z. The structure of the MICU1-MICU2 complex unveils the regulation of the mitochondrial calcium uniporter. EMBO J 2020; 39:e104285. [PMID: 32790952 DOI: 10.15252/embj.2019104285] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/20/2020] [Accepted: 06/29/2020] [Indexed: 12/17/2022] Open
Abstract
The MICU1-MICU2 heterodimer regulates the mitochondrial calcium uniporter (MCU) and mitochondrial calcium uptake. Herein, we present two crystal structures of the MICU1-MICU2 heterodimer, in which Ca2+ -free and Ca2+ -bound EF-hands are observed in both proteins, revealing both electrostatic and hydrophobic interfaces. Furthermore, we show that MICU1 interacts with EMRE, another regulator of MCU, through a Ca2+ -dependent alkaline groove. Ca2+ binding strengthens the MICU1-EMRE interaction, which in turn facilitates Ca2+ uptake. Conversely, the MICU1-MCU interaction is favored in the absence of Ca2+ , thus inhibiting the channel activity. This Ca2+ -dependent switch illuminates how calcium signals are transmitted from regulatory subunits to the calcium channel and the transition between gatekeeping and activation channel functions. Furthermore, competition with an EMRE peptide alters the uniporter threshold in resting conditions and elevates Ca2+ accumulation in stimulated mitochondria, confirming the gatekeeper role of the MICU1-MICU2 heterodimer. Taken together, these structural and functional data provide new insights into the regulation of mitochondrial calcium uptake.
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Affiliation(s)
- Wenping Wu
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Qingya Shen
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Ruiling Zhang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Zhiyu Qiu
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Youjun Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Jimin Zheng
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Zongchao Jia
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
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120
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Discovery of EMRE in fungi resolves the true evolutionary history of the mitochondrial calcium uniporter. Nat Commun 2020; 11:4031. [PMID: 32788582 PMCID: PMC7423614 DOI: 10.1038/s41467-020-17705-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/06/2020] [Indexed: 01/25/2023] Open
Abstract
Calcium (Ca2+) influx into mitochondria occurs through a Ca2+-selective uniporter channel, which regulates essential cellular processes in eukaryotic organisms. Previous evolutionary analyses of its pore-forming subunits MCU and EMRE, and gatekeeper MICU1, pinpointed an evolutionary paradox: the presence of MCU homologs in fungal species devoid of any other uniporter components and of mt-Ca2+ uptake. Here, we trace the mt-Ca2+ uniporter evolution across 1,156 fully-sequenced eukaryotes and show that animal and fungal MCUs represent two distinct paralogous subfamilies originating from an ancestral duplication. Accordingly, we find EMRE orthologs outside Holoza and uncover the existence of an animal-like uniporter within chytrid fungi, which enables mt-Ca2+ uptake when reconstituted in vivo in the yeast Saccharomyces cerevisiae. Our study represents the most comprehensive phylogenomic analysis of the mt-Ca2+ uptake system and demonstrates that MCU, EMRE, and MICU formed the core of the ancestral opisthokont uniporter, with major implications for comparative structural and functional studies. The mitochondrial calcium uptake system, crucial for cellular processes, evolved in ancient eukaryotes. Here, authors perform a phylogenomic analysis across 1,156 eukaryotes, and show that previously identified animal and fungal genes in this system originated from an ancestral duplication.
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121
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Wang Y, Han Y, She J, Nguyen NX, Mootha VK, Bai XC, Jiang Y. Structural insights into the Ca 2+-dependent gating of the human mitochondrial calcium uniporter. eLife 2020; 9:e60513. [PMID: 32762847 PMCID: PMC7442490 DOI: 10.7554/elife.60513] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial Ca2+ uptake is mediated by an inner mitochondrial membrane protein called the mitochondrial calcium uniporter. In humans, the uniporter functions as a holocomplex consisting of MCU, EMRE, MICU1 and MICU2, among which MCU and EMRE form a subcomplex and function as the conductive channel while MICU1 and MICU2 are EF-hand proteins that regulate the channel activity in a Ca2+-dependent manner. Here, we present the EM structures of the human mitochondrial calcium uniporter holocomplex (uniplex) in the presence and absence of Ca2+, revealing distinct Ca2+ dependent assembly of the uniplex. Our structural observations suggest that Ca2+ changes the dimerization interaction between MICU1 and MICU2, which in turn determines how the MICU1-MICU2 subcomplex interacts with the MCU-EMRE channel and, consequently, changes the distribution of the uniplex assemblies between the blocked and unblocked states.
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Affiliation(s)
- Yan Wang
- Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Howard Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Yan Han
- Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Howard Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Ji She
- Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Nam X Nguyen
- Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Howard Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Vamsi K Mootha
- Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Broad InstituteCambridgeUnited States
| | - Xiao-chen Bai
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
- Howard Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
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122
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Böhme I, Schönherr R, Eberle J, Bosserhoff AK. Membrane Transporters and Channels in Melanoma. Rev Physiol Biochem Pharmacol 2020; 181:269-374. [PMID: 32737752 DOI: 10.1007/112_2020_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent research has revealed that ion channels and transporters can be important players in tumor development, progression, and therapy resistance in melanoma. For example, members of the ABC family were shown to support cancer stemness-like features in melanoma cells, while several members of the TRP channel family were reported to act as tumor suppressors.Also, many transporter proteins support tumor cell viability and thus suppress apoptosis induction by anticancer therapy. Due to the high number of ion channels and transporters and the resulting high complexity of the field, progress in understanding is often focused on single molecules and is in total rather slow. In this review, we aim at giving an overview about a broad subset of ion transporters, also illustrating some aspects of the field, which have not been addressed in detail in melanoma. In context with the other chapters in this special issue on "Transportome Malfunctions in the Cancer Spectrum," a comparison between melanoma and these tumors will be possible.
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Affiliation(s)
- Ines Böhme
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Roland Schönherr
- Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Jürgen Eberle
- Department of Dermatology, Venerology and Allergology, Skin Cancer Center Charité, University Medical Center Charité, Berlin, Germany
| | - Anja Katrin Bosserhoff
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany. .,Comprehensive Cancer Center (CCC) Erlangen-EMN, Erlangen, Germany.
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123
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Wang C, Jacewicz A, Delgado BD, Baradaran R, Long SB. Structures reveal gatekeeping of the mitochondrial Ca 2+ uniporter by MICU1-MICU2. eLife 2020; 9:e59991. [PMID: 32667285 PMCID: PMC7434445 DOI: 10.7554/elife.59991] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 07/14/2020] [Indexed: 12/11/2022] Open
Abstract
The mitochondrial calcium uniporter is a Ca2+-gated ion channel complex that controls mitochondrial Ca2+ entry and regulates cell metabolism. MCU and EMRE form the channel while Ca2+-dependent regulation is conferred by MICU1 and MICU2 through an enigmatic process. We present a cryo-EM structure of an MCU-EMRE-MICU1-MICU2 holocomplex comprising MCU and EMRE subunits from the beetle Tribolium castaneum in complex with a human MICU1-MICU2 heterodimer at 3.3 Å resolution. With analogy to how neuronal channels are blocked by protein toxins, a uniporter interaction domain on MICU1 binds to a channel receptor site comprising MCU and EMRE subunits to inhibit ion flow under resting Ca2+ conditions. A Ca2+-bound structure of MICU1-MICU2 at 3.1 Å resolution indicates how Ca2+-dependent changes enable dynamic response to cytosolic Ca2+ signals.
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Affiliation(s)
- Chongyuan Wang
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
| | - Agata Jacewicz
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
| | - Bryce D Delgado
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
- Graduate Program in Biochemistry and Structural Biology, Cell and Developmental Biology, and Molecular Biology, Weill Cornell Medicine Graduate School of Medical SciencesNew YorkUnited States
| | - Rozbeh Baradaran
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
| | - Stephen Barstow Long
- Structural Biology Program, Memorial Sloan Kettering Cancer CenterNew YorkUnited States
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124
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AMPK, Mitochondrial Function, and Cardiovascular Disease. Int J Mol Sci 2020; 21:ijms21144987. [PMID: 32679729 PMCID: PMC7404275 DOI: 10.3390/ijms21144987] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/04/2020] [Accepted: 07/06/2020] [Indexed: 12/12/2022] Open
Abstract
Adenosine monophosphate-activated protein kinase (AMPK) is in charge of numerous catabolic and anabolic signaling pathways to sustain appropriate intracellular adenosine triphosphate levels in response to energetic and/or cellular stress. In addition to its conventional roles as an intracellular energy switch or fuel gauge, emerging research has shown that AMPK is also a redox sensor and modulator, playing pivotal roles in maintaining cardiovascular processes and inhibiting disease progression. Pharmacological reagents, including statins, metformin, berberine, polyphenol, and resveratrol, all of which are widely used therapeutics for cardiovascular disorders, appear to deliver their protective/therapeutic effects partially via AMPK signaling modulation. The functions of AMPK during health and disease are far from clear. Accumulating studies have demonstrated crosstalk between AMPK and mitochondria, such as AMPK regulation of mitochondrial homeostasis and mitochondrial dysfunction causing abnormal AMPK activity. In this review, we begin with the description of AMPK structure and regulation, and then focus on the recent advances toward understanding how mitochondrial dysfunction controls AMPK and how AMPK, as a central mediator of the cellular response to energetic stress, maintains mitochondrial homeostasis. Finally, we systemically review how dysfunctional AMPK contributes to the initiation and progression of cardiovascular diseases via the impact on mitochondrial function.
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125
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Ghosh S, Basu Ball W, Madaris TR, Srikantan S, Madesh M, Mootha VK, Gohil VM. An essential role for cardiolipin in the stability and function of the mitochondrial calcium uniporter. Proc Natl Acad Sci U S A 2020; 117:16383-16390. [PMID: 32601238 PMCID: PMC7368250 DOI: 10.1073/pnas.2000640117] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Calcium uptake by the mitochondrial calcium uniporter coordinates cytosolic signaling events with mitochondrial bioenergetics. During the past decade all protein components of the mitochondrial calcium uniporter have been identified, including MCU, the pore-forming subunit. However, the specific lipid requirements, if any, for the function and formation of this channel complex are currently not known. Here we utilize yeast, which lacks the mitochondrial calcium uniporter, as a model system to address this problem. We use heterologous expression to functionally reconstitute human uniporter machinery both in wild-type yeast as well as in mutants defective in the biosynthesis of phosphatidylethanolamine, phosphatidylcholine, or cardiolipin (CL). We uncover a specific requirement of CL for in vivo reconstituted MCU stability and activity. The CL requirement of MCU is evolutionarily conserved with loss of CL triggering rapid turnover of MCU homologs and impaired calcium transport. Furthermore, we observe reduced abundance and activity of endogenous MCU in mammalian cellular models of Barth syndrome, which is characterized by a partial loss of CL. MCU abundance is also decreased in the cardiac tissue of Barth syndrome patients. Our work raises the hypothesis that impaired mitochondrial calcium transport contributes to the pathogenesis of Barth syndrome, and more generally, showcases the utility of yeast phospholipid mutants in dissecting the phospholipid requirements of ion channel complexes.
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Affiliation(s)
- Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Writoban Basu Ball
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Travis R Madaris
- Department of Medicine, Division of Nephrology, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
| | - Subramanya Srikantan
- Department of Medicine, Division of Nephrology, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
| | - Muniswamy Madesh
- Department of Medicine, Division of Nephrology, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
| | - Vamsi K Mootha
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114;
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843;
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126
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Dumbuya H, Hafez SY, Oancea E. Cross talk between calcium and ROS regulate the UVA-induced melanin response in human melanocytes. FASEB J 2020; 34:11605-11623. [PMID: 32658369 DOI: 10.1096/fj.201903024r] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 06/01/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
Exposure to high doses of solar long wavelength ultraviolet radiation (UVA) damages human skin via reactive oxygen species (ROS). Whether physiological UVA doses also generate ROS that has an effect on the skin remains unknown. We previously showed that in human epidermal melanocytes UVA activates a G-protein coupled signaling pathway that leads to calcium mobilization and increased melanin. Here, we report that ROS generated by the UVA phototransduction pathway are critical cellular messengers required to augment melanin. Using simultaneous UVA exposure and live-cell imaging of primary human melanocytes, we found that physiological doses of UVA generate two spatiotemporally distinct sources of ROS: one upstream of the G-protein activation that potentiates calcium responses, and another source downstream of calcium, in the mitochondria (ROSmito ). UVA-evoked signaling led to mitochondrial calcium uptake via mitochondrial calcium uniporter to promote ROSmito production leading to melanin synthesis. Our findings reveal a novel mechanism in which ROS function as signaling messengers necessary for melanin production, thus having a protective role in the UVA-induced skin response.
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Affiliation(s)
- Hawasatu Dumbuya
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI, USA
| | - Salwa Y Hafez
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI, USA.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Elena Oancea
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI, USA
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127
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Abstract
Ca2+ is a ubiquitous and dynamic second messenger molecule that is induced by many factors including receptor activation, environmental factors, and voltage, leading to pleiotropic effects on cell function including changes in migration, metabolism and transcription. As such, it is not surprising that aberrant regulation of Ca2+ signals can lead to pathological phenotypes, including cancer progression. However, given the highly context-specific nature of Ca2+-dependent changes in cell function, delineation of its role in cancer has been a challenge. Herein, we discuss the distinct roles of Ca2+ signaling within and between each type of cancer, including consideration of the potential of therapeutic strategies targeting these signaling pathways.
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Affiliation(s)
- Scott Gross
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Pranava Mallu
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Hinal Joshi
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Bryant Schultz
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Christina Go
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Jonathan Soboloff
- Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States; Department of Medical Genetics & Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.
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128
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Wang F, Li A, Li QN, Fan LH, Wang ZB, Meng TG, Hou Y, Schatten H, Sun QY, Ou XH. Effects of mitochondria-associated Ca 2+ transporters suppression on oocyte activation. Cell Biochem Funct 2020; 39:248-257. [PMID: 32643225 DOI: 10.1002/cbf.3571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 12/14/2022]
Abstract
Oocyte activation deficiency leads to female infertility. [Ca2+ ]i oscillations are required for mitochondrial energy supplement transition from the resting to the excited state, but the underlying mechanisms are still very little known. Three mitochondrial Ca2+ channels, Mitochondria Calcium Uniporter (MCU), Na+ /Ca2+ Exchanger (NCLX) and Voltage-dependent Ca2+ Channel (VDAC), were deactivated by inhibitors RU360, CGP37157 and Erastin, respectively. Both Erastin and CGP37157 inhibited mitochondrial activity significantly while attenuating [Ca2+ ]i and [Ca2+ ]m oscillations, which caused developmental block of pronuclear formation. Thus, NCLX and VDAC are two mitochondria-associated Ca2+ transporter proteins regulating oocyte activation, which may be used as potential targets to treat female infertility. SIGNIFICANCE OF THE STUDY: NCLX and VDAC are two mitochondria-associated Ca2+ transporter proteins regulating oocyte activation.
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Affiliation(s)
- Feng Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Ang Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qian-Nan Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Li-Hua Fan
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhen-Bo Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Tie-Gang Meng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yi Hou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri, USA
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
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129
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Yin HZ, Wang HL, Ji SG, Medvedeva YV, Tian G, Bazrafkan AK, Maki NZ, Akbari Y, Weiss JH. Rapid Intramitochondrial Zn2+ Accumulation in CA1 Hippocampal Pyramidal Neurons After Transient Global Ischemia: A Possible Contributor to Mitochondrial Disruption and Cell Death. J Neuropathol Exp Neurol 2020; 78:655-664. [PMID: 31150090 DOI: 10.1093/jnen/nlz042] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial Zn2+ accumulation, particularly in CA1 neurons, occurs after ischemia and likely contributes to mitochondrial dysfunction and subsequent neurodegeneration. However, the relationship between mitochondrial Zn2+ accumulation and their disruption has not been examined at the ultrastructural level in vivo. We employed a cardiac arrest model of transient global ischemia (TGI), combined with Timm's sulfide silver labeling, which inserts electron dense metallic silver granules at sites of labile Zn2+ accumulation, and used transmission electron microscopy (TEM) to examine subcellular loci of the Zn2+ accumulation. In line with prior studies, TGI-induced damage to CA1 was far greater than to CA3 pyramidal neurons, and was substantially progressive in the hours after reperfusion (being significantly greater after 4- than 1-hour recovery). Intriguingly, TEM examination of Timm's-stained sections revealed substantial Zn2+ accumulation in many postischemic CA1 mitochondria, which was strongly correlated with their swelling and disruption. Furthermore, paralleling the evolution of neuronal injury, both the number of mitochondria containing Zn2+ and the degree of their disruption were far greater at 4- than 1-hour recovery. These data provide the first direct characterization of Zn2+ accumulation in CA1 mitochondria after in vivo TGI, and support the idea that targeting these events could yield therapeutic benefits.
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Affiliation(s)
| | | | - Sung G Ji
- Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, California
| | | | | | | | | | | | - John H Weiss
- Department of Neurology
- Department of Anatomy & Neurobiology, University of California, Irvine, Irvine, California
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
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130
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Structure and mechanism of the mitochondrial Ca 2+ uniporter holocomplex. Nature 2020; 582:129-133. [PMID: 32494073 DOI: 10.1038/s41586-020-2309-6] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 04/15/2020] [Indexed: 12/13/2022]
Abstract
Mitochondria take up Ca2+ through the mitochondrial calcium uniporter complex to regulate energy production, cytosolic Ca2+ signalling and cell death1,2. In mammals, the uniporter complex (uniplex) contains four core components: the pore-forming MCU protein, the gatekeepers MICU1 and MICU2, and an auxiliary subunit, EMRE, essential for Ca2+ transport3-8. To prevent detrimental Ca2+ overload, the activity of MCU must be tightly regulated by MICUs, which sense changes in cytosolic Ca2+ concentrations to switch MCU on and off9,10. Here we report cryo-electron microscopic structures of the human mitochondrial calcium uniporter holocomplex in inhibited and Ca2+-activated states. These structures define the architecture of this multicomponent Ca2+-uptake machinery and reveal the gating mechanism by which MICUs control uniporter activity. Our work provides a framework for understanding regulated Ca2+ uptake in mitochondria, and could suggest ways of modulating uniporter activity to treat diseases related to mitochondrial Ca2+ overload.
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131
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Yun HR, Jo YH, Kim J, Shin Y, Kim SS, Choi TG. Roles of Autophagy in Oxidative Stress. Int J Mol Sci 2020; 21:ijms21093289. [PMID: 32384691 PMCID: PMC7246723 DOI: 10.3390/ijms21093289] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 12/21/2022] Open
Abstract
Autophagy is a catabolic process for unnecessary or dysfunctional cytoplasmic contents by lysosomal degradation pathways. Autophagy is implicated in various biological processes such as programmed cell death, stress responses, elimination of damaged organelles and development. The role of autophagy as a crucial mediator has been clarified and expanded in the pathological response to redox signalling. Autophagy is a major sensor of the redox signalling. Reactive oxygen species (ROS) are highly reactive molecules that are generated as by-products of cellular metabolism, principally by mitochondria. Mitochondrial ROS (mROS) are beneficial or detrimental to cells depending on their concentration and location. mROS function as redox messengers in intracellular signalling at physiologically low level, whereas excessive production of mROS causes oxidative damage to cellular constituents and thus incurs cell death. Hence, the balance of autophagy-related stress adaptation and cell death is important to comprehend redox signalling-related pathogenesis. In this review, we attempt to provide an overview the basic mechanism and function of autophagy in the context of response to oxidative stress and redox signalling in pathology.
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Affiliation(s)
- Hyeong Rok Yun
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Korea; (H.R.Y.); (Y.S.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Korea; (Y.H.J.); (J.K.)
| | - Yong Hwa Jo
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Korea; (Y.H.J.); (J.K.)
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
| | - Jieun Kim
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Korea; (Y.H.J.); (J.K.)
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
| | - Yoonhwa Shin
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Korea; (H.R.Y.); (Y.S.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Korea; (Y.H.J.); (J.K.)
| | - Sung Soo Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Korea; (H.R.Y.); (Y.S.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Korea; (Y.H.J.); (J.K.)
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
- Correspondence: (S.S.K.); (T.G.C.); Tel.: +82-2-961-0524 (S.S.K.); +82-2-961-0287 (T.G.C.)
| | - Tae Gyu Choi
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Korea; (Y.H.J.); (J.K.)
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
- Correspondence: (S.S.K.); (T.G.C.); Tel.: +82-2-961-0524 (S.S.K.); +82-2-961-0287 (T.G.C.)
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132
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Wang SF, Chen S, Tseng LM, Lee HC. Role of the mitochondrial stress response in human cancer progression. Exp Biol Med (Maywood) 2020; 245:861-878. [PMID: 32326760 PMCID: PMC7268930 DOI: 10.1177/1535370220920558] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
IMPACT STATEMENT Dysregulated mitochondria often occurred in cancers. Mitochondrial dysfunction might contribute to cancer progression. We reviewed several mitochondrial stresses in cancers. Mitochondrial stress responses might contribute to cancer progression. Several mitochondrion-derived molecules (ROS, Ca2+, oncometabolites, exported mtDNA, mitochondrial double-stranded RNA, humanin, and MOTS-c), integrated stress response, and mitochondrial unfolded protein response act as retrograde signaling pathways and might be critical in the development and progression of cancer. Targeting these mitochondrial stress responses may be an important strategy for cancer treatment.
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Affiliation(s)
- Sheng-Fan Wang
- Department of Pharmacy, Taipei Veterans General Hospital, 112 Taipei
- School of Pharmacy, Taipei Medical University, 110 Taipei
- Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, 112 Taipei
| | - Shiuan Chen
- Department of Cancer Biology, Beckman Research Institute of the City of Hope, CA 91010, USA
| | - Ling-Ming Tseng
- Division of General Surgery, Department of Surgery, Comprehensive Breast Health Center, Taipei Veterans General Hospital, 112 Taipei
- Department of Surgery, School of Medicine, National Yang-Ming University, 112 Taipei
| | - Hsin-Chen Lee
- Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, 112 Taipei
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133
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Chong SJF, Marchi S, Petroni G, Kroemer G, Galluzzi L, Pervaiz S. Noncanonical Cell Fate Regulation by Bcl-2 Proteins. Trends Cell Biol 2020; 30:537-555. [PMID: 32307222 DOI: 10.1016/j.tcb.2020.03.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/15/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022]
Abstract
Bcl-2 proteins are widely known as key controllers of mitochondrial outer membrane permeabilization, arguably the most important step of intrinsic apoptosis. Accumulating evidence indicate that most, if not all, members of the Bcl-2 protein family also mediate a number of apoptosis-unrelated functions. Intriguingly, many of these functions ultimately impinge on cell fate decisions via apoptosis-dependent or -independent mechanisms, delineating a complex network through which Bcl-2 family members regulate cell survival and death. Here, we critically discuss the mechanisms through which Bcl-2 proteins influence cell fate as they regulate autophagy, cellular senescence, inflammation, bioenergetic metabolism, Ca2+ fluxes, and redox homeostasis.
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Affiliation(s)
| | - Saverio Marchi
- Department of Clinical and Molecular Sciences, Marche Polytechnic University, Ancona, Italy
| | - Giulia Petroni
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
| | - Guido Kroemer
- Equipe Labellisée par la Ligue Contre le Cancer, INSERM U1138, Centre de Recherche des Cordeliers, Paris, France; Metabolomics and Cell Biology Platforms, Gustave Roussy Comprehensive Cancer Institute, Villejuif, France; Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-, HP, Paris, France; Suzhou Institute for Systems Medicine, Chinese Academy of Sciences, Suzhou, China; Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden; Université de Paris, Paris, France
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA; Université de Paris, Paris, France; Sandra and Edward Meyer Cancer Center, New York, NY, USA; Caryl and Israel Englander Institute for Precision Medicine, New York, NY, USA; Department of Dermatology, Yale School of Medicine, New Haven, CT, USA.
| | - Shazib Pervaiz
- Université de Paris, Paris, France; Department of Physiology, YLL School of Medicine and NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore; National University Cancer Institute, National University Health System, Singapore.
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134
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Yuan Y, Cao C, Wen M, Li M, Dong Y, Wu L, Wu J, Cui T, Li D, Chou JJ, OuYang B. Structural Characterization of the N-Terminal Domain of the Dictyostelium discoideum Mitochondrial Calcium Uniporter. ACS OMEGA 2020; 5:6452-6460. [PMID: 32258880 PMCID: PMC7114133 DOI: 10.1021/acsomega.9b04045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/20/2020] [Indexed: 06/11/2023]
Abstract
The mitochondrial calcium uniporter (MCU) plays a critical role in mitochondrial calcium uptake into the matrix. In metazoans, the uniporter is a tightly regulated multicomponent system, including the pore-forming subunit MCU and several regulators (MICU1, MICU2, and Essential MCU REgulator, EMRE). The calcium-conducting activity of metazoan MCU requires the single-transmembrane protein EMRE. Dictyostelium discoideum (Dd), however, developed a simplified uniporter for which the pore-forming MCU (DdMCU) alone is necessary and sufficient for calcium influx. Here, we report a crystal structure of the N-terminal domain (NTD) of DdMCU at 1.7 Å resolution. The DdMCU-NTD contains four helices and two strands arranged in a fold that is completely different from the known structures of other MCU-NTD homologues. Biochemical and biophysical analyses of DdMCU-NTD in solution indicated that the domain exists as high-order oligomers. Mutagenesis showed that the acidic residues Asp60, Glu72, and Glu74, which appeared to mediate the interface II, as observed in the crystal structure, participated in the self-assembly of DdMCU-NTD. Intriguingly, the oligomeric complex was disrupted in the presence of calcium. We propose that the calcium-triggered dissociation of NTD regulates the channel activity of DdMCU by a yet unknown mechanism.
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Affiliation(s)
- Yuan Yuan
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
| | - Chan Cao
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
| | - Maorong Wen
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
| | - Min Li
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
| | - Ying Dong
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
| | - Lijie Wu
- Shanghai Institute for Advanced Immunochemical
Studies and iHuman Institute, ShanghaiTech
University, Shanghai 201210, China
| | - Jian Wu
- Ninth People’s
Hospital, Shanghai Jiao Tong University
School of Medicine, Shanghai 200125, China
| | - Tanxing Cui
- Department of Biological
Chemistry and Molecular Pharmacology, Harvard
Medical School, Boston, Massachusetts 02115, United States
| | - Dianfan Li
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
| | - James J. Chou
- Department of Biological
Chemistry and Molecular Pharmacology, Harvard
Medical School, Boston, Massachusetts 02115, United States
| | - Bo OuYang
- State Key Laboratory
of Molecular Biology, CAS Center for Excellence in Molecular Cell
Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese
Academy of Sciences, University of Chinese
Academy of Sciences, 333 Haike Road, Shanghai 201203, China
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135
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Gonzalez-Rodriguez P, Zampese E, Surmeier DJ. Selective neuronal vulnerability in Parkinson's disease. PROGRESS IN BRAIN RESEARCH 2020; 252:61-89. [PMID: 32247375 DOI: 10.1016/bs.pbr.2020.02.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease, disabling millions worldwide. Despite the imperative PD poses, at present, there is no cure or means of slowing progression. This gap is attributable to our incomplete understanding of the factors driving pathogenesis. Research over the past several decades suggests that both cell-autonomous and non-cell autonomous processes contribute to the neuronal dysfunction underlying PD symptoms. The thesis of this review is that an intersection of these processes governs the pattern of pathology in PD. Studies of substantia nigra pars compacta (SNc) dopaminergic neurons, whose loss is responsible for the core motor symptoms of PD, suggest that they have a combination of traits-a long, highly branched axon, autonomous activity, and elevated mitochondrial oxidant stress-that predispose them to non-cell autonomous drivers of pathogenesis, like misfolded forms of alpha-synuclein (α-SYN) and inflammation. The literature surrounding these issues will be briefly summarized, and the translational implications of an intersectional hypothesis of PD pathogenesis discussed.
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Affiliation(s)
| | - Enrico Zampese
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.
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136
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Cell organelles as targets of mammalian cadmium toxicity. Arch Toxicol 2020; 94:1017-1049. [PMID: 32206829 DOI: 10.1007/s00204-020-02692-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023]
Abstract
Ever increasing environmental presence of cadmium as a consequence of industrial activities is considered a health hazard and is closely linked to deteriorating global health status. General animal and human cadmium exposure ranges from ingestion of foodstuffs sourced from heavily polluted hotspots and cigarette smoke to widespread contamination of air and water, including cadmium-containing microplastics found in household water. Cadmium is promiscuous in its effects and exerts numerous cellular perturbations based on direct interactions with macromolecules and its capacity to mimic or displace essential physiological ions, such as iron and zinc. Cell organelles use lipid membranes to form complex tightly-regulated, compartmentalized networks with specialized functions, which are fundamental to life. Interorganellar communication is crucial for orchestrating correct cell behavior, such as adaptive stress responses, and can be mediated by the release of signaling molecules, exchange of organelle contents, mechanical force generated through organelle shape changes or direct membrane contact sites. In this review, cadmium effects on organellar structure and function will be critically discussed with particular consideration to disruption of organelle physiology in vertebrates.
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137
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Xing Y, Wang M, Wang J, Nie Z, Wu G, Yang X, Shen Y. Dimerization of MICU Proteins Controls Ca 2+ Influx through the Mitochondrial Ca 2+ Uniporter. Cell Rep 2020; 26:1203-1212.e4. [PMID: 30699349 DOI: 10.1016/j.celrep.2019.01.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/12/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022] Open
Abstract
The mitochondrial Ca2+ uniporter complex (MCUC) is responsible for Ca2+ influx into the mitochondrial matrix, playing critical roles in various mitochondrial functions. Eukaryotic MCUC consists of multiple subunits, and its Ca2+ influx activity is controlled by regulatory subunits, including mitochondrial Ca2+ uptake 1 (MICU1) and its paralogs (MICU2 and MICU3). However, the underlying mechanism remains unclear. Here, we determined multiple crystal structures of MICU2 and MICU3 from Homo sapiens. Our data demonstrate that distinct MICU protein N-domains determine the specific type of MICU dimers that perform the opposing roles in mitochondrial Ca2+ uptake at low cytosolic Ca2+ levels. In contrast, at high cytosolic Ca2+ levels, all MICU proteins undergo dimer rearrangement induced by Ca2+ binding, which releases the suppression of the MCUC pore-forming subunit and promotes the influx of large amounts of Ca2+. Altogether, our results elucidate the delicate mechanism of mitochondrial Ca2+ uptake regulation by MICU proteins.
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Affiliation(s)
- Yangfei Xing
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Mingfei Wang
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Jia Wang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Zhenzhen Nie
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Guangyan Wu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China.
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China; Synergetic Innovation Center of Chemical Science and Engineering, 94 Weijin Road, Tianjin 300071, China.
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138
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Sisalli MJ, Feliciello A, Della Notte S, Di Martino R, Borzacchiello D, Annunziato L, Scorziello A. Nuclear-encoded NCX3 and AKAP121: Two novel modulators of mitochondrial calcium efflux in normoxic and hypoxic neurons. Cell Calcium 2020; 87:102193. [PMID: 32193001 DOI: 10.1016/j.ceca.2020.102193] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 12/30/2022]
Abstract
Mitochondria are highly dynamic organelles extremely important for cell survival. Their structure resembles that of prokaryotic cells since they are composed with two membranes, the inner (IMM) and the outer mitochondrial membrane (OMM) delimitating the intermembrane space (IMS) and the matrix which contains mitochondrial DNA (mtDNA). This structure is strictly related to mitochondrial function since they produce the most of the cellular ATP through the oxidative phosphorylation which generate the electrochemical gradient at the two sides of the inner mitochondrial membrane an essential requirement for mitochondrial function. Cells of highly metabolic demand like those composing muscle, liver and brain, are particularly dependent on mitochondria for their activities. Mitochondria undergo to continual changes in morphology since, they fuse and divide, branch and fragment, swell and extend. Importantly, they move throughout the cell to deliver ATP and other metabolites where they are mostly required. Along with the capability to control energy metabolism, mitochondria play a critical role in the regulation of many physiological processes such as programmed cell death, autophagy, redox signalling, and stem cells reprogramming. All these phenomena are regulated by Ca2+ ions within this organelle. This review will discuss the molecular mechanisms regulating mitochondrial calcium cycling in physiological and pathological conditions with particular regard to their impact on mitochondrial dynamics and function during ischemia. Particular emphasis will be devoted to the role played by NCX3 and AKAP121 as new molecular targets for mitochondrial function and dysfunction.
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Affiliation(s)
- Maria Josè Sisalli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy
| | - Antonio Feliciello
- Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, Italy
| | - Salvatore Della Notte
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy
| | - Rossana Di Martino
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy
| | - Domenica Borzacchiello
- Department of Molecular Medicine and Medical Biotechnology, Federico II University of Naples, Italy
| | | | - Antonella Scorziello
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Italy.
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139
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Park J, Lee Y, Park T, Kang JY, Mun SA, Jin M, Yang J, Eom SH. Structure of the MICU1-MICU2 heterodimer provides insights into the gatekeeping threshold shift. IUCRJ 2020; 7:355-365. [PMID: 32148862 PMCID: PMC7055370 DOI: 10.1107/s2052252520001840] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/10/2020] [Indexed: 06/10/2023]
Abstract
Mitochondrial calcium uptake proteins 1 and 2 (MICU1 and MICU2) mediate mitochondrial Ca2+ influx via the mitochondrial calcium uniporter (MCU). Its molecular action for Ca2+ uptake is tightly controlled by the MICU1-MICU2 heterodimer, which comprises Ca2+ sensing proteins which act as gatekeepers at low [Ca2+] or facilitators at high [Ca2+]. However, the mechanism underlying the regulation of the Ca2+ gatekeeping threshold for mitochondrial Ca2+ uptake through the MCU by the MICU1-MICU2 heterodimer remains unclear. In this study, we determined the crystal structure of the apo form of the human MICU1-MICU2 heterodimer that functions as the MCU gatekeeper. MICU1 and MICU2 assemble in the face-to-face heterodimer with salt bridges and me-thio-nine knobs stabilizing the heterodimer in an apo state. Structural analysis suggests how the heterodimer sets a higher Ca2+ threshold than the MICU1 homodimer. The structure of the heterodimer in the apo state provides a framework for understanding the gatekeeping role of the MICU1-MICU2 heterodimer.
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Affiliation(s)
- Jongseo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Youngjin Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Taein Park
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Jung Youn Kang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Sang A Mun
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Minwoo Jin
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Jihyeong Yang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Soo Hyun Eom
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
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140
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Kanemaru K, Suzuki J, Taiko I, Iino M. Red fluorescent CEPIA indicators for visualization of Ca 2+ dynamics in mitochondria. Sci Rep 2020; 10:2835. [PMID: 32071363 PMCID: PMC7029041 DOI: 10.1038/s41598-020-59707-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/04/2020] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial Ca2+ dynamics are involved in the regulation of multifarious cellular processes, including intracellular Ca2+ signalling, cell metabolism and cell death. Use of mitochondria-targeted genetically encoded Ca2+ indicators has revealed intercellular and subcellular heterogeneity of mitochondrial Ca2+ dynamics, which are assumed to be determined by distinct thresholds of Ca2+ increases at each subcellular mitochondrial domain. The balance between Ca2+ influx through the mitochondrial calcium uniporter and extrusion by cation exchangers across the inner mitochondrial membrane may define the threshold; however, the precise mechanisms remain to be further explored. We here report the new red fluorescent genetically encoded Ca2+ indicators, R-CEPIA3mt and R-CEPIA4mt, which are targeted to mitochondria and their Ca2+ affinities are engineered to match the intramitochondrial Ca2+ concentrations. They enable visualization of mitochondrial Ca2+ dynamics with high spatiotemporal resolution in parallel with the use of green fluorescent probes and optogenetic tools. Thus, R-CEPIA3mt and R-CEPIA4mt are expected to be a useful tool for elucidating the mechanisms of the complex mitochondrial Ca2+ dynamics and their functions.
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Affiliation(s)
- Kazunori Kanemaru
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Junji Suzuki
- Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Isamu Taiko
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
- Department of Physiology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan.
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141
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Tang NH, Kim KW, Xu S, Blazie SM, Yee BA, Yeo GW, Jin Y, Chisholm AD. The mRNA Decay Factor CAR-1/LSM14 Regulates Axon Regeneration via Mitochondrial Calcium Dynamics. Curr Biol 2020; 30:865-876.e7. [PMID: 31983639 DOI: 10.1016/j.cub.2019.12.061] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/26/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022]
Abstract
mRNA decay factors regulate mRNA turnover by recruiting non-translating mRNAs and targeting them for translational repression and mRNA degradation. How mRNA decay pathways regulate cellular function in vivo with specificity is poorly understood. Here, we show that C. elegans mRNA decay factors, including the translational repressors CAR-1/LSM14 and CGH-1/DDX6, and the decapping enzymes DCAP-1/DCP1, function in neurons to differentially regulate axon development, maintenance, and regrowth following injury. In neuronal cell bodies, CAR-1 fully colocalizes with CGH-1 and partially colocalizes with DCAP-1, suggesting that mRNA decay components form at least two types of cytoplasmic granules. Following axon injury in adult neurons, loss of CAR-1 or CGH-1 results in increased axon regrowth and growth cone formation, whereas loss of DCAP-1 or DCAP-2 results in reduced regrowth. To determine how CAR-1 inhibits regrowth, we analyzed mRNAs bound to pan-neuronally expressed GFP::CAR-1 using a crosslinking and immunoprecipitation-based approach. Among the putative mRNA targets of CAR-1, we characterized the roles of micu-1, a regulator of the mitochondrial calcium uniporter MCU-1, in axon injury. We show that loss of car-1 results increased MICU-1 protein levels, and that enhanced axon regrowth in car-1 mutants is dependent on micu-1 and mcu-1. Moreover, axon injury induces transient calcium influx into axonal mitochondria, dependent on MCU-1. In car-1 loss-of-function mutants and in micu-1 overexpressing animals, the axonal mitochondrial calcium influx is more sustained, which likely underlies enhanced axon regrowth. Our data uncover a novel pathway that controls axon regrowth through axonal mitochondrial calcium uptake.
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Affiliation(s)
- Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kyung Won Kim
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Suhong Xu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stephen M Blazie
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Brian A Yee
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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142
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Gökerküçük EB, Tramier M, Bertolin G. Imaging Mitochondrial Functions: from Fluorescent Dyes to Genetically-Encoded Sensors. Genes (Basel) 2020; 11:E125. [PMID: 31979408 PMCID: PMC7073610 DOI: 10.3390/genes11020125] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are multifunctional organelles that are crucial to cell homeostasis. They constitute the major site of energy production for the cell, they are key players in signalling pathways using secondary messengers such as calcium, and they are involved in cell death and redox balance paradigms. Mitochondria quickly adapt their dynamics and biogenesis rates to meet the varying energy demands of the cells, both in normal and in pathological conditions. Therefore, understanding simultaneous changes in mitochondrial functions is crucial in developing mitochondria-based therapy options for complex pathological conditions such as cancer, neurological disorders, and metabolic syndromes. To this end, fluorescence microscopy coupled to live imaging represents a promising strategy to track these changes in real time. In this review, we will first describe the commonly available tools to follow three key mitochondrial functions using fluorescence microscopy: Calcium signalling, mitochondrial dynamics, and mitophagy. Then, we will focus on how the development of genetically-encoded fluorescent sensors became a milestone for the understanding of these mitochondrial functions. In particular, we will show how these tools allowed researchers to address several biochemical activities in living cells, and with high spatiotemporal resolution. With the ultimate goal of tracking multiple mitochondrial functions simultaneously, we will conclude by presenting future perspectives for the development of novel genetically-encoded fluorescent biosensors.
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Affiliation(s)
| | | | - Giulia Bertolin
- Univ Rennes, CNRS, IGDR [Institut de génétique et développement de Rennes] UMR 6290, F-35000 Rennes, France
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143
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Abstract
Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.
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Affiliation(s)
- Tyler M Bauer
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
| | - Elizabeth Murphy
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
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144
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Danese A, Marchi S, Vitto VAM, Modesti L, Leo S, Wieckowski MR, Giorgi C, Pinton P. Cancer-Related Increases and Decreases in Calcium Signaling at the Endoplasmic Reticulum-Mitochondria Interface (MAMs). Rev Physiol Biochem Pharmacol 2020; 185:153-193. [PMID: 32789789 DOI: 10.1007/112_2020_43] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endoplasmic reticulum (ER)-mitochondria regions are specialized subdomains called also mitochondria-associated membranes (MAMs). MAMs allow regulation of lipid synthesis and represent hubs for ion and metabolite signaling. As these two organelles can module both the amplitude and the spatiotemporal patterns of calcium (Ca2+) signals, this particular interaction controls several Ca2+-dependent pathways well known for their contribution to tumorigenesis, such as metabolism, survival, sensitivity to cell death, and metastasis. Mitochondria-mediated apoptosis arises from mitochondrial Ca2+ overload, permeabilization of the mitochondrial outer membrane, and the release of mitochondrial apoptotic factors into the cytosol. Decreases in Ca2+ signaling at the ER-mitochondria interface are being studied in depth as failure of apoptotic-dependent cell death is one of the predominant characteristics of cancer cells. However, some recent papers that linked MAMs Ca2+ crosstalk-related upregulation to tumor onset and progression have aroused the interest of the scientific community.In this review, we will describe how different MAMs-localized proteins modulate the effectiveness of Ca2+-dependent apoptotic stimuli by causing both increases and decreases in the ER-mitochondria interplay and, specifically, by modulating Ca2+ signaling.
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Affiliation(s)
- Alberto Danese
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Saverio Marchi
- Department of Clinical and Molecular Sciences, Marche Polytechnic University, Ancona, Italy
| | - Veronica Angela Maria Vitto
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Lorenzo Modesti
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Sara Leo
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Carlotta Giorgi
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
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145
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Ji SG, Medvedeva YV, Weiss JH. Zn 2+ entry through the mitochondrial calcium uniporter is a critical contributor to mitochondrial dysfunction and neurodegeneration. Exp Neurol 2019; 325:113161. [PMID: 31881218 DOI: 10.1016/j.expneurol.2019.113161] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/19/2019] [Accepted: 12/21/2019] [Indexed: 12/19/2022]
Abstract
Excitotoxic Ca2+ accumulation contributes to ischemic neurodegeneration, and Ca2+ can enter the mitochondria through the mitochondrial calcium uniporter (MCU) to promote mitochondrial dysfunction. Yet, Ca2+-targeted therapies have met limited success. A growing body of evidence has highlighted the underappreciated importance of Zn2+, which also accumulates in neurons after ischemia and can induce mitochondrial dysfunction and cell death. While studies have indicated that Zn2+ can also enter the mitochondria through the MCU, the specificity of the pore's role in Zn2+-triggered injury is still debated. Present studies use recently available MCU knockout mice to examine how the deletion of this channel impacts deleterious effects of cytosolic Zn2+ loading. In cultured cortical neurons from MCU knockout mice, we find significantly reduced mitochondrial Zn2+ accumulation. Correspondingly, these neurons were protected from both acute and delayed Zn2+-triggered mitochondrial dysfunction, including mitochondrial reactive oxygen species generation, depolarization, swelling and inhibition of respiration. Furthermore, when toxic extramitochondrial effects of Ca2+ entry were moderated, both cultured neurons (exposed to Zn2+) and CA1 neurons of hippocampal slices (subjected to prolonged oxygen glucose deprivation to model ischemia) from MCU knockout mice displayed decreased neurodegeneration. Finally, to examine the therapeutic applicability of these findings, we added an MCU blocker after toxic Zn2+ exposure in wildtype neurons (to induce post-insult MCU blockade). This significantly attenuated the delayed evolution of both mitochondrial dysfunction and neurotoxicity. These data-combining both genetic and pharmacologic tools-support the hypothesis that Zn2+ entry through the MCU is a critical contributor to ischemic neurodegeneration that could be targeted for neuroprotection.
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Affiliation(s)
- Sung G Ji
- Department of Anatomy & Neurobiology, University of California, Irvine, United States of America
| | - Yuliya V Medvedeva
- Department of Neurology, University of California, Irvine, United States of America
| | - John H Weiss
- Department of Anatomy & Neurobiology, University of California, Irvine, United States of America; Department of Neurology, University of California, Irvine, United States of America.
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146
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Boczek T, Radzik T, Ferenc B, Zylinska L. The Puzzling Role of Neuron-Specific PMCA Isoforms in the Aging Process. Int J Mol Sci 2019; 20:ijms20246338. [PMID: 31888192 PMCID: PMC6941135 DOI: 10.3390/ijms20246338] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 01/02/2023] Open
Abstract
The aging process is a physiological phenomenon associated with progressive changes in metabolism, genes expression, and cellular resistance to stress. In neurons, one of the hallmarks of senescence is a disturbance of calcium homeostasis that may have far-reaching detrimental consequences on neuronal physiology and function. Among several proteins involved in calcium handling, plasma membrane Ca2+-ATPase (PMCA) is the most sensitive calcium detector controlling calcium homeostasis. PMCA exists in four main isoforms and PMCA2 and PMCA3 are highly expressed in the brain. The overall effects of impaired calcium extrusion due to age-dependent decline of PMCA function seem to accumulate with age, increasing the susceptibility to neurotoxic insults. To analyze the PMCA role in neuronal cells, we have developed stable transfected differentiated PC12 lines with down-regulated PMCA2 or PMCA3 isoforms to mimic age-related changes. The resting Ca2+ increased in both PMCA-deficient lines affecting the expression of several Ca2+-associated proteins, i.e., sarco/endoplasmic Ca2+-ATPase (SERCA), calmodulin, calcineurin, GAP43, CCR5, IP3Rs, and certain types of voltage-gated Ca2+ channels (VGCCs). Functional studies also demonstrated profound changes in intracellular pH regulation and mitochondrial metabolism. Moreover, modification of PMCAs membrane composition triggered some adaptive processes to counterbalance calcium overload, but the reduction of PMCA2 appeared to be more detrimental to the cells than PMCA3.
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Affiliation(s)
- Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Tomasz Radzik
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
| | - Bozena Ferenc
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
- Correspondence: ; Tel.: +48-42-272-5680
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147
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Boyman L, Karbowski M, Lederer WJ. Regulation of Mitochondrial ATP Production: Ca 2+ Signaling and Quality Control. Trends Mol Med 2019; 26:21-39. [PMID: 31767352 DOI: 10.1016/j.molmed.2019.10.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/16/2019] [Accepted: 10/23/2019] [Indexed: 02/06/2023]
Abstract
Cardiac ATP production primarily depends on oxidative phosphorylation in mitochondria and is dynamically regulated by Ca2+ levels in the mitochondrial matrix as well as by cytosolic ADP. We discuss mitochondrial Ca2+ signaling and its dysfunction which has recently been linked to cardiac pathologies including arrhythmia and heart failure. Similar dysfunction in other excitable and long-lived cells including neurons is associated with neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Central to this new understanding is crucial Ca2+ regulation of both mitochondrial quality control and ATP production. Mitochondria-associated membrane (MAM) signaling from the sarcoplasmic reticulum (SR) and the endoplasmic reticulum (ER) to mitochondria is discussed. We propose future research directions that emphasize a need to define quantitatively the physiological roles of MAMs, as well as mitochondrial quality control and ATP production.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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148
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Overexpression of Mitochondrial Calcium Uniporter Causes Neuronal Death. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:1681254. [PMID: 31737163 PMCID: PMC6816006 DOI: 10.1155/2019/1681254] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/24/2019] [Accepted: 08/22/2019] [Indexed: 12/13/2022]
Abstract
Neurodegenerative diseases are a large and heterogeneous group of disorders characterized by selective and progressive death of specific neuronal subtypes. In most of the cases, the pathophysiology is still poorly understood, although a number of hypotheses have been proposed. Among these, dysregulation of Ca2+ homeostasis and mitochondrial dysfunction represent two broadly recognized early events associated with neurodegeneration. However, a direct link between these two hypotheses can be drawn. Mitochondria actively participate to global Ca2+ signaling, and increases of [Ca2+] inside organelle matrix are known to sustain energy production to modulate apoptosis and remodel cytosolic Ca2+ waves. Most importantly, while mitochondrial Ca2+ overload has been proposed as the no-return signal, triggering apoptotic or necrotic neuronal death, until now direct evidences supporting this hypothesis, especially in vivo, are limited. Here, we took advantage of the identification of the mitochondrial Ca2+ uniporter (MCU) and tested whether mitochondrial Ca2+ signaling controls neuronal cell fate. We overexpressed MCU both in vitro, in mouse primary cortical neurons, and in vivo, through stereotaxic injection of MCU-coding adenoviral particles in the brain cortex. We first measured mitochondrial Ca2+ uptake using quantitative genetically encoded Ca2+ probes, and we observed that the overexpression of MCU causes a dramatic increase of mitochondrial Ca2+ uptake both at resting and after membrane depolarization. MCU-mediated mitochondrial Ca2+ overload causes alteration of organelle morphology and dysregulation of global Ca2+ homeostasis. Most importantly, MCU overexpression in vivo is sufficient to trigger gliosis and neuronal loss. Overall, we demonstrated that mitochondrial Ca2+ overload is per se sufficient to cause neuronal cell death both in vitro and in vivo, thus highlighting a potential key step in neurodegeneration.
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149
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Farris S, Ward JM, Carstens KE, Samadi M, Wang Y, Dudek SM. Hippocampal Subregions Express Distinct Dendritic Transcriptomes that Reveal Differences in Mitochondrial Function in CA2. Cell Rep 2019; 29:522-539.e6. [PMID: 31597108 PMCID: PMC6894405 DOI: 10.1016/j.celrep.2019.08.093] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/15/2019] [Accepted: 08/27/2019] [Indexed: 12/15/2022] Open
Abstract
RNA localization is one mechanism neurons use to spatially and temporally regulate gene expression at synapses. Here, we test the hypothesis that cells exhibiting distinct forms of synaptic plasticity will have differences in dendritically localized RNAs. Indeed, we discover that each major subregion of the adult mouse hippocampus expresses a unique complement of dendritic RNAs. Specifically, we describe more than 1,000 differentially expressed dendritic RNAs, suggesting that RNA localization and local translation are regulated in a cell type-specific manner. Furthermore, by focusing Gene Ontology analyses on the plasticity-resistant CA2, we identify an enrichment of mitochondria-associated pathways in CA2 cell bodies and dendrites, and we provide functional evidence that these pathways differentially influence plasticity and mitochondrial respiration in CA2. These data indicate that differences in dendritic transcriptomes may regulate cell type-specific properties important for learning and memory and may influence region-specific differences in disease pathology.
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Affiliation(s)
- Shannon Farris
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - James M Ward
- Integrative Bioinformatics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Kelly E Carstens
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Mahsa Samadi
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Yu Wang
- Cellular and Molecular Pathology, National Toxicology Program, NIH, Research Triangle Park, NC 27709, USA
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA.
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150
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Tarasova NV, Vishnyakova PA, Logashina YA, Elchaninov AV. Mitochondrial Calcium Uniporter Structure and Function in Different Types of Muscle Tissues in Health and Disease. Int J Mol Sci 2019; 20:ijms20194823. [PMID: 31569359 PMCID: PMC6801532 DOI: 10.3390/ijms20194823] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/12/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023] Open
Abstract
Calcium ions (Ca2+) influx to mitochondrial matrix is crucial for the life of a cell. Mitochondrial calcium uniporter (mtCU) is a protein complex which consists of the pore-forming subunit (MCU) and several regulatory subunits. MtCU is the main contributor to inward Ca2+ currents through the inner mitochondrial membrane. Extensive investigations of mtCU involvement into normal and pathological molecular pathways started from the moment of discovery of its molecular components. A crucial role of mtCU in the control of these pathways is now recognized in both health and disease. In particular, impairments of mtCU function have been demonstrated for cardiovascular and skeletal muscle-associated pathologies. This review summarizes the current state of knowledge on mtCU structure, regulation, and function in different types of muscle tissues in health and disease.
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Affiliation(s)
- Nadezhda V Tarasova
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
| | - Polina A Vishnyakova
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
| | - Yulia A Logashina
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russia.
| | - Andrey V Elchaninov
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
- Scientific Research Institute of Human Morphology, 3 Tsurupa Street, Moscow 117418, Russia.
- Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Street, Moscow 117198, Russia.
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