51
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Ectromelia Virus Affects Mitochondrial Network Morphology, Distribution, and Physiology in Murine Fibroblasts and Macrophage Cell Line. Viruses 2018; 10:v10050266. [PMID: 29772718 PMCID: PMC5977259 DOI: 10.3390/v10050266] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are multifunctional organelles that participate in numerous processes in response to viral infection, but they are also a target for viruses. The aim of this study was to define subcellular events leading to alterations in mitochondrial morphology and function during infection with ectromelia virus (ECTV). We used two different cell lines and a combination of immunofluorescence techniques, confocal and electron microscopy, and flow cytometry to address subcellular changes following infection. Early in infection of L929 fibroblasts and RAW 264.7 macrophages, mitochondria gathered around viral factories. Later, the mitochondrial network became fragmented, forming punctate mitochondria that co-localized with the progeny virions. ECTV-co-localized mitochondria associated with the cytoskeleton components. Mitochondrial membrane potential, mitochondrial fission–fusion, mitochondrial mass, and generation of reactive oxygen species (ROS) were severely altered later in ECTV infection leading to damage of mitochondria. These results suggest an important role of mitochondria in supplying energy for virus replication and morphogenesis. Presumably, mitochondria participate in transport of viral particles inside and outside of the cell and/or they are a source of membranes for viral envelope formation. We speculate that the observed changes in the mitochondrial network organization and physiology in ECTV-infected cells provide suitable conditions for viral replication and morphogenesis.
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Mouton-Liger F, Rosazza T, Sepulveda-Diaz J, Ieang A, Hassoun SM, Claire E, Mangone G, Brice A, Michel PP, Corvol JC, Corti O. Parkin deficiency modulates NLRP3 inflammasome activation by attenuating an A20-dependent negative feedback loop. Glia 2018; 66:1736-1751. [PMID: 29665074 PMCID: PMC6190839 DOI: 10.1002/glia.23337] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 03/16/2018] [Accepted: 03/19/2018] [Indexed: 12/13/2022]
Abstract
Neuroinflammation and mitochondrial dysfunction, key mechanisms in the
pathogenesis of Parkinson's disease (PD), are usually explored independently.
Loss‐of‐function mutations of PARK2 and PARK6,
encoding the E3 ubiquitin protein ligase Parkin and the mitochondrial
serine/threonine kinase PINK1, account for a large proportion of cases of autosomal
recessive early‐onset PD. PINK1 and Parkin regulate mitochondrial quality control and
have been linked to the modulation of innate immunity pathways. We report here an
exacerbation of NLRP3 inflammasome activation by specific inducers in microglia and
bone marrow‐derived macrophages from Park2−/− and Pink1−/− mice. The caspase 1‐dependent release of IL‐1β and IL‐18 was, therefore,
enhanced in Park2−/− and Pink1−/− cells. This defect was confirmed in blood‐derived macrophages from patients
with PARK2 mutations and was reversed by MCC950, which specifically
inhibits NLRP3 inflammasome complex formation. Enhanced NLRP3 signaling in
Parkin‐deficient cells was accompanied by a lack of induction of A20, a well‐known
negative regulator of the NF‐κB pathway recently shown to attenuate NLRP3
inflammasome activity. We also found an inverse correlation between A20 abundance and
IL‐1β release, in human macrophages challenged with NLRP3 inflammasome inducers.
Overall, our observations suggest that the A20/NLRP3‐inflammasome axis participates
in the pathogenesis of PARK2‐linked PD, paving the way for the
exploration of its potential as a biomarker and treatment target.
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Affiliation(s)
- François Mouton-Liger
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Thibault Rosazza
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Julia Sepulveda-Diaz
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Amélie Ieang
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Sidi-Mohamed Hassoun
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Emilie Claire
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Graziella Mangone
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France.,AP-HP, Hôpital de la Pitié Salpêtrière, Clinical Investigation Center of Neurology (CIC-1422), Department of Neurology, Hôpital Pitié-Salpêtrière, Paris, F-75013, France
| | - Alexis Brice
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Patrick P Michel
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
| | - Jean-Christophe Corvol
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France.,AP-HP, Hôpital de la Pitié Salpêtrière, Clinical Investigation Center of Neurology (CIC-1422), Department of Neurology, Hôpital Pitié-Salpêtrière, Paris, F-75013, France
| | - Olga Corti
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France.,Inserm, U1127, Paris, F-75013, France.,CNRS, UMR 7225, Paris, F-75013, France.,Sorbonne Universités, Paris, F-75013, France
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53
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Yoo SM, Jung YK. A Molecular Approach to Mitophagy and Mitochondrial Dynamics. Mol Cells 2018; 41:18-26. [PMID: 29370689 PMCID: PMC5792708 DOI: 10.14348/molcells.2018.2277] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 11/22/2017] [Accepted: 11/23/2017] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial quality control systems are essential for the maintenance of functional mitochondria. At the organelle level, they include mitochondrial biogenesis, fusion and fission, to compensate for mitochondrial function, and mitophagy, for degrading damaged mitochondria. Specifically, in mitophagy, the target mitochondria are recognized by the autophagosomes and delivered to the lysosome for degradation. In this review, we describe the mechanisms of mitophagy and the factors that play an important role in this process. In particular, we focus on the roles of mitophagy adapters and receptors in the recognition of damaged mitochondria by autophagosomes. In addition, we also address a functional association of mitophagy with mitochondrial dynamics through the interaction of mitophagy adaptor and receptor proteins with mitochondrial fusion and fission proteins.
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Affiliation(s)
- Seung-Min Yoo
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul 08826,
Korea
| | - Yong-Keun Jung
- Global Research Laboratory, School of Biological Sciences, Seoul National University, Seoul 08826,
Korea
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54
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Thornton C, Jones A, Nair S, Aabdien A, Mallard C, Hagberg H. Mitochondrial dynamics, mitophagy and biogenesis in neonatal hypoxic-ischaemic brain injury. FEBS Lett 2017; 592:812-830. [PMID: 29265370 DOI: 10.1002/1873-3468.12943] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/22/2017] [Accepted: 12/11/2017] [Indexed: 12/13/2022]
Abstract
Hypoxic-ischaemic encephalopathy, resulting from asphyxia during birth, affects 2-3 in every 1000 term infants and depending on severity, brings about life-changing neurological consequences or death. This hypoxic-ischaemia (HI) results in a delayed neural energy failure during which the majority of brain injury occurs. Currently, there are limited treatment options and additional therapies are urgently required. Mitochondrial dysfunction acts as a focal point in injury development in the immature brain. Not only do mitochondria become permeabilised, but recent findings implicate perturbations in mitochondrial dynamics (fission, fusion), mitophagy and biogenesis. Mitoprotective therapies may therefore offer a new avenue of intervention for babies who suffer lifelong disabilities due to birth asphyxia.
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Affiliation(s)
- Claire Thornton
- Perinatal Brain Injury Group, Division of Imaging Sciences and Biomedical Engineering, Centre for the Developing Brain, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - Adam Jones
- Perinatal Brain Injury Group, Division of Imaging Sciences and Biomedical Engineering, Centre for the Developing Brain, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - Syam Nair
- Perinatal Center, Department of Physiology, Institute of Physiology and Neuroscience, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Afra Aabdien
- Perinatal Brain Injury Group, Division of Imaging Sciences and Biomedical Engineering, Centre for the Developing Brain, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK
| | - Carina Mallard
- Perinatal Center, Department of Physiology, Institute of Physiology and Neuroscience, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Henrik Hagberg
- Perinatal Brain Injury Group, Division of Imaging Sciences and Biomedical Engineering, Centre for the Developing Brain, King's College London, King's Health Partners, St. Thomas' Hospital, London, UK.,Perinatal Center, Department of Clinical Sciences & Physiology and Neuroscience, Sahlgrenska Academy, University of Gothenburg, Sweden
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55
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Sil P, Muse G, Martinez J. A ravenous defense: canonical and non-canonical autophagy in immunity. Curr Opin Immunol 2017; 50:21-31. [PMID: 29125936 DOI: 10.1016/j.coi.2017.10.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/04/2017] [Indexed: 12/29/2022]
Abstract
While classically considered a survival mechanism employed during nutrient scarcity, the autophagy pathway operates in multiple scenarios wherein a return to homeostasis or degradative removal of an invader is required. Now recognized as a pathway with vast immunoregulatory power, autophagy can no longer serve as a 'one size fits all' term, as its machinery can be recruited to different pathogens, at different times, with different outcomes. Both canonical autophagy and the molecularly related, yet divergent pathways non-canonical autophagy are key players in proper host defense and allow us an opportunity to tailor infectious disease intervention and treatment to its specific pathway.
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Affiliation(s)
- Payel Sil
- Immunity, Inflammation, and Disease Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Ginger Muse
- Immunity, Inflammation, and Disease Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Jennifer Martinez
- Immunity, Inflammation, and Disease Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA.
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56
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Mitophagy and age-related pathologies: Development of new therapeutics by targeting mitochondrial turnover. Pharmacol Ther 2017; 178:157-174. [DOI: 10.1016/j.pharmthera.2017.04.005] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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57
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Abstract
Chlamydiae are bacterial pathogens that grow in vacuolar inclusions. Dendritic cells (DCs) disintegrate these compartments, thereby eliminating the microbes, through auto/xenophagy, which also promotes chlamydial antigen presentation via MHC I. Here, we show that TNF-α controls this pathway by driving cytosolic phospholipase (cPLA)2-mediated arachidonic acid (AA) production. AA then impairs mitochondrial function, which disturbs the development and integrity of these energy-dependent parasitic inclusions, while a simultaneous metabolic switch towards aerobic glycolysis promotes DC survival. Tubulin deacetylase/autophagy regulator HDAC6 associates with disintegrated inclusions, thereby further disrupting their subcellular localisation and stability. Bacterial remnants are decorated with defective mitochondria, mito-aggresomal structures, and components of the ubiquitin/autophagy machinery before they are degraded via mito-xenophagy. The mechanism depends on cytoprotective HSP25/27, the E3 ubiquitin ligase Parkin and HDAC6 and promotes chlamydial antigen generation for presentation on MHC I. We propose that this novel mito-xenophagic pathway linking innate and adaptive immunity is critical for effective DC-mediated anti-bacterial resistance.
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58
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Harris J, Lang T, Thomas JP, Sukkar MB, Nabar NR, Kehrl JH. Autophagy and inflammasomes. Mol Immunol 2017; 86:10-15. [DOI: 10.1016/j.molimm.2017.02.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 02/16/2017] [Accepted: 02/19/2017] [Indexed: 12/25/2022]
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59
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Mouton-Liger F, Jacoupy M, Corvol JC, Corti O. PINK1/Parkin-Dependent Mitochondrial Surveillance: From Pleiotropy to Parkinson's Disease. Front Mol Neurosci 2017; 10:120. [PMID: 28507507 PMCID: PMC5410576 DOI: 10.3389/fnmol.2017.00120] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/10/2017] [Indexed: 12/26/2022] Open
Abstract
Parkinson's disease (PD) is one of the most frequent neurodegenerative disease caused by the preferential, progressive degeneration of the dopaminergic (DA) neurons of the substantia nigra (SN) pars compacta. PD is characterized by a multifaceted pathological process involving protein misfolding, mitochondrial dysfunction, neuroinflammation and metabolism deregulation. The molecular mechanisms governing the complex interplay between the different facets of this process are still unknown. PARK2/Parkin and PARK6/PINK1, two genes responsible for familial forms of PD, act as a ubiquitous core signaling pathway, coupling mitochondrial stress to mitochondrial surveillance, by regulating mitochondrial dynamics, the removal of damaged mitochondrial components by mitochondria-derived vesicles, mitophagy, and mitochondrial biogenesis. Over the last decade, PINK1/Parkin-dependent mitochondrial quality control emerged as a pleiotropic regulatory pathway. Loss of its function impinges on a number of physiological processes suspected to contribute to PD pathogenesis. Its role in the regulation of innate immunity and inflammatory processes stands out, providing compelling support to the contribution of non-cell-autonomous immune mechanisms in PD. In this review, we illustrate the central role of this multifunctional pathway at the crossroads between mitochondrial stress, neuroinflammation and metabolism. We discuss how its dysfunction may contribute to PD pathogenesis and pinpoint major unresolved questions in the field.
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Affiliation(s)
- Francois Mouton-Liger
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France.,Centre National de la Recherche Scientifique, UMR 7225Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR S 1127Paris, France.,Institut du Cerveau et de la Moelle épinière, ICMParis, France
| | - Maxime Jacoupy
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France.,Centre National de la Recherche Scientifique, UMR 7225Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR S 1127Paris, France.,Institut du Cerveau et de la Moelle épinière, ICMParis, France
| | - Jean-Christophe Corvol
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France.,Centre National de la Recherche Scientifique, UMR 7225Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR S 1127Paris, France.,Institut du Cerveau et de la Moelle épinière, ICMParis, France.,Department of Neurology, Institut National de la Santé et de la Recherche Médicale, Assistance-Publique Hôpitaux de Paris, CIC-1422, Hôpital Pitié-SalpêtrièreParis, France
| | - Olga Corti
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France.,Centre National de la Recherche Scientifique, UMR 7225Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR S 1127Paris, France.,Institut du Cerveau et de la Moelle épinière, ICMParis, France
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60
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Beckermann KE, Dudzinski SO, Rathmell JC. Dysfunctional T cell metabolism in the tumor microenvironment. Cytokine Growth Factor Rev 2017; 35:7-14. [PMID: 28456467 DOI: 10.1016/j.cytogfr.2017.04.003] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 12/17/2022]
Abstract
Metabolic and signaling pathways are integrated to determine T cell fate and function. As stimulated T cells gain distinct effector functions, specific metabolic programs and demands are also adopted. These changes are essential for T cell effector function, and alterations or dysregulation of metabolic pathways can modulate T cell function. One physiological setting that impacts T cell metabolism is the tumor microenvironment. The metabolism of cancer cells themselves can limit nutrients and accumulate waste products. In addition to the expression of inhibitory ligands that directly modify T cell physiology, T cell metabolism may be strongly inhibited in the tumor microenvironment. This suppression of T cell metabolism may inhibit effector T cell activity while promoting suppressive regulatory T cells, and act as a barrier to effective immunotherapies. A thorough understanding of the effect of the tumor microenvironment on the immune system will support the continued improvement of immune based therapies for cancer patients.
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Affiliation(s)
- Kathryn E Beckermann
- Department of Medicine, Division of Hematology/Oncology, Vanderbilt-Ingram Cancer Center, 2220 Pierce Avenue, Nashville, TN 37232, USA
| | - Stephanie O Dudzinski
- Department of Biomedical Engineering, 2301 Vanderbilt Place, Nashville, TN 37235, USA
| | - Jeffrey C Rathmell
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, 1211 Vanderbilt University Medical Center, Nashville, TN, USA.
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61
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Taylor D, Gottlieb RA. Parkin-mediated mitophagy is downregulated in browning of white adipose tissue. Obesity (Silver Spring) 2017; 25:704-712. [PMID: 28240819 PMCID: PMC5373982 DOI: 10.1002/oby.21786] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Browning of white adipose tissue (WAT) promotes increased energy expenditure through the action of uncoupling protein 1 (UCP1) and is an attractive target to promote weight loss in obesity. Lowering of mitochondrial membrane potential by UCP1 is uniquely beneficial in this context; in other tissues, reduced membrane potential promotes mitochondrial clearance via mitophagy. It is unknown how parkin-mediated mitophagy is regulated in beige adipocytes. METHODS The relationship between parkin expression and WAT browning was investigated in 3T3-L1 adipocytes and parkin-deficient male C57BL/6 mice in response to pharmacological browning stimuli. RESULTS Rosiglitazone treatment in 3T3-L1 adipocytes promoted mitochondrial biogenesis, UCP1 expression, and mitochondrial uncoupling. Parkin expression was decreased and reduced mitochondrial-associated parkin, and p62 indicated a reduction in mitophagy activity. Parkin overexpression prevented mitochondrial remodeling in response to rosiglitazone. In CL 316,243-treated wild-type mice, decreased parkin expression was observed in subcutaneous inguinal WAT, where UCP1 was strongly induced. CL 316,243 treatment weakly induced UCP1 expression in the gonadal depot, where parkin expression was unchanged. In contrast, parkin-deficient mice exhibited robust UCP1 expression in gonadal WAT following CL 316,243 treatment. CONCLUSIONS WAT browning was associated with a decrease in parkin-mediated mitophagy, and parkin expression antagonized browning of WAT.
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Affiliation(s)
- David Taylor
- The Cedars-Sinai Heart Institute, Barbra Streisand Women’s Heart Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Roberta A. Gottlieb
- The Cedars-Sinai Heart Institute, Barbra Streisand Women’s Heart Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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62
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Kim MJ, Yoon JH, Ryu JH. Mitophagy: a balance regulator of NLRP3 inflammasome activation. BMB Rep 2017; 49:529-535. [PMID: 27439607 PMCID: PMC5227293 DOI: 10.5483/bmbrep.2016.49.10.115] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Indexed: 12/24/2022] Open
Abstract
The NLRP3 inflammasome is activated by a variety of external or host-derived stimuli and its activation initiates an inflammatory response through caspase-1 activation, resulting in inflammatory cytokine IL-1β maturation and secretion. The NLRP3 inflammasome activation is a kind of innate immune response, most likely mediated by myeloid cells acting as a host defense mechanism. However, if this activation is not properly regulated, excessive inflammation induced by overactivated NLRP3 inflammasome can be detrimental to the host, causing tissue damage and organ dysfunction, eventually causing several diseases. Previous studies have suggested that mitochondrial damage may be a cause of NLRP3 inflammasome activation and autophagy, which is a conserved self-degradation process that negatively regulates NLRP3 inflammasome activation. Recently, mitochondria-selective autophagy, termed mitophagy, has emerged as a central player for maintaining mitochondrial homeostasis through the elimination of damaged mitochondria, leading to the prevention of hyperinflammation triggered by NLRP3 inflammasome activation. In this review, we will first focus on the molecular mechanisms of NLRP3 inflammasome activation and NLRP3 inflammasome-related diseases. We will then discuss autophagy, especially mitophagy, as a negative regulator of NLPP3 inflammasome activation by examining recent advances in research. [BMB Reports 2016; 49(10): 529-535]
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Affiliation(s)
- Min-Ji Kim
- Research Center for Natural Human Defense System, Brain Korea 21 PLUS Project for Medical Science, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Joo-Heon Yoon
- Research Center for Natural Human Defense System, Brain Korea 21 PLUS Project for Medical Science, Department of Otorhinolaryngology, and The Airway Mucus Institute, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Ji-Hwan Ryu
- Brain Korea 21 PLUS Project for Medical Science and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 03722, Korea
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63
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64
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Bingol B, Sheng M. Mechanisms of mitophagy: PINK1, Parkin, USP30 and beyond. Free Radic Biol Med 2016; 100:210-222. [PMID: 27094585 DOI: 10.1016/j.freeradbiomed.2016.04.015] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/15/2016] [Accepted: 04/15/2016] [Indexed: 12/16/2022]
Abstract
Mitochondrial quality control is central for maintaining a healthy population of mitochondria. Two Parkinson's disease genes, mitochondrial kinase PINK1 and ubiquitin ligase Parkin, degrade damaged mitochondria though mitophagy. In this pathway, PINK1 senses mitochondrial damage and activates Parkin by phosphorylating Parkin and ubiquitin. Activated Parkin then builds ubiquitin chains on damaged mitochondria to tag them for degradation in lysosomes. USP30 deubiquitinase acts as a brake on mitophagy by opposing Parkin-mediated ubiquitination. Human genetic data point to a role for mitophagy defects in neurodegenerative diseases. This review highlights the molecular mechanisms of the mitophagy pathway and the recent advances in the understanding of mitophagy in vivo.
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Affiliation(s)
- Baris Bingol
- Department of Neuroscience, Genentech Inc, South San Francisco, CA 94080, USA.
| | - Morgan Sheng
- Department of Neuroscience, Genentech Inc, South San Francisco, CA 94080, USA
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65
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Parkin and mitophagy in cancer. Oncogene 2016; 36:1315-1327. [PMID: 27593930 DOI: 10.1038/onc.2016.302] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/04/2016] [Accepted: 07/04/2016] [Indexed: 02/07/2023]
Abstract
Mitophagy, the selective engulfment and clearance of mitochondria, is essential for the homeostasis of a healthy network of functioning mitochondria and prevents excessive production of cytotoxic reactive oxygen species from damaged mitochondria. The mitochondrially targeted PTEN-induced kinase-1 (PINK1) and the E3 ubiquitin ligase Parkin are well-established synergistic mediators of the mitophagy of dysfunctional mitochondria. This pathway relies on the ubiquitination of a number of mitochondrial outer membrane substrates and subsequent docking of autophagy receptor proteins to selectively clear mitochondria. There are also alternate Parkin-independent mitophagy pathways mediated by BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 and Nip-3 like protein X as well as other effectors. There is increasing evidence that ablation of mitophagy accelerates a number of pathologies. Familial Parkinsonism is associated with loss-of-function mutations in PINK1 and Parkin. A growing number of studies have observed a correlation between impaired Parkin activity and enhanced cancer development, leading to the emerging concept that Parkin activity, or mitophagy in general, is a tumour suppression mechanism. This review examines the molecular mechanisms of mitophagy and highlights the potential links between Parkin and the hallmarks of cancer that may influence tumour development and progression.
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66
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The Mitochondria-Regulated Immune Pathway Activated in the C. elegans Intestine Is Neuroprotective. Cell Rep 2016; 16:2399-414. [PMID: 27545884 PMCID: PMC7780887 DOI: 10.1016/j.celrep.2016.07.077] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 05/25/2016] [Accepted: 07/27/2016] [Indexed: 01/03/2023] Open
Abstract
Immunological mediators that originate outside the nervous system can affect neuronal health. However, their roles in neurodegeneration remain largely unknown. Here, we show that the p38MAPK-mediated immune pathway activated in intestinal cells of Caenorhabditis elegans upon mitochondrial dysfunction protects neurons in a cell-non-autonomous fashion. Specifically, mitochondrial complex I dysfunction induced by rotenone activates the p38MAPK/CREB/ATF-7-dependent innate immune response pathway in intestinal cells of C. elegans. Activation of p38MAPK in the gut is neuroprotective. Enhancing the p38MAPK-mediated immune pathway in intestinal cells alone suppresses rotenone-induced dopaminergic neuron loss, while downregulating it in the intestine exacerbates neurodegeneration. The p38MAPK/ATF-7 immune pathway modulates autophagy and requires autophagy and the PTEN-induced putative kinase PINK-1 for conferring neuroprotection. Thus, mitochondrial damage induces the clearance of mitochondria by the immune pathway, protecting the organism from the toxic effects of mitochondrial dysfunction. We propose that mitochondria are subject to constant surveillance by innate immune mechanisms. Chikka et al. find that mitochondrial complex I damage activates the p38MAPK/ATF-7 signaling pathway in the intestine of C. elegans. Activation of the p38MAPK/ATF-7 immune pathway in the intestine is neuroprotective and sufficient to prevent rotenone-induced degeneration of dopaminergic neurons.
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Elliott EI, Sutterwala FS. Initiation and perpetuation of NLRP3 inflammasome activation and assembly. Immunol Rev 2016; 265:35-52. [PMID: 25879282 DOI: 10.1111/imr.12286] [Citation(s) in RCA: 609] [Impact Index Per Article: 76.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome is a multiprotein complex that orchestrates innate immune responses to infection and cell stress through activation of caspase-1 and maturation of inflammatory cytokines pro-interleukin-1β (pro-IL-1β) and pro-IL-18. Activation of the inflammasome during infection can be protective, but unregulated NLRP3 inflammasome activation in response to non-pathogenic endogenous or exogenous stimuli can lead to unintended pathology. NLRP3 associates with mitochondria and mitochondrial molecules, and activation of the NLRP3 inflammasome in response to diverse stimuli requires cation flux, mitochondrial Ca(2+) uptake, and mitochondrial reactive oxygen species accumulation. It remains uncertain whether NLRP3 surveys mitochondrial integrity and senses mitochondrial damage, or whether mitochondria simply serve as a physical platform for inflammasome assembly. The structure of the active, caspase-1-processing NLRP3 inflammasome also requires further clarification, but recent studies describing the prion-like properties of ASC have advanced the understanding of how inflammasome assembly and caspase-1 activation occur while raising new questions regarding the propagation and resolution of NLRP3 inflammasome activation. Here, we review the mechanisms and pathways regulating NLRP3 inflammasome activation, discuss emerging concepts in NLRP3 complex organization, and expose the knowledge gaps hindering a comprehensive understanding of NLRP3 activation.
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Affiliation(s)
- Eric I Elliott
- Inflammation Program, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Molecular and Cellular Biology, University of Iowa, Iowa City, IA, USA; Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
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Innovative Target Therapies Are Able to Block the Inflammation Associated with Dysfunction of the Cholesterol Biosynthesis Pathway. Int J Mol Sci 2015; 17:ijms17010047. [PMID: 26729102 PMCID: PMC4730292 DOI: 10.3390/ijms17010047] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/23/2015] [Accepted: 12/24/2015] [Indexed: 01/24/2023] Open
Abstract
The cholesterol pathway is an essential biochemical process aimed at the synthesis of bioactive molecules involved in multiple crucial cellular functions. The end products of this pathway are sterols, such as cholesterol, which are essential components of cell membranes, precursors of steroid hormones, bile acids and other molecules such as ubiquinone. Several diseases are caused by defects in this metabolic pathway: the most severe forms of which cause neurological involvement (psychomotor retardation and cerebellar ataxia) as a result of a variety of cellular impairments, including mitochondrial dysfunction. These pathologies are induced by convergent mechanisms in which the mitochondrial unit plays a pivotal role contributing to defective apoptosis, autophagy and mitophagy processes. Unraveling these mechanisms would contribute to the development of effective drug treatments for these disorders. In addition, the development of biochemical models could have a substantial impact on the understanding of the mechanism of action of drugs that act on this pathway in multifactor disorders. In this review we will focus in particular on inhibitors of cholesterol synthesis, mitochondria-targeted drugs and inhibitors of the inflammasome.
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Lionaki E, Markaki M, Palikaras K, Tavernarakis N. Mitochondria, autophagy and age-associated neurodegenerative diseases: New insights into a complex interplay. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1412-23. [DOI: 10.1016/j.bbabio.2015.04.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/10/2015] [Accepted: 04/20/2015] [Indexed: 12/22/2022]
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Optineurin: The autophagy connection. Exp Eye Res 2015; 144:73-80. [PMID: 26142952 DOI: 10.1016/j.exer.2015.06.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/03/2015] [Accepted: 06/30/2015] [Indexed: 01/13/2023]
Abstract
Optineurin is a cytosolic protein encoded by the OPTN gene. Mutations of OPTN are associated with normal tension glaucoma and amyotrophic lateral sclerosis. Autophagy is an intracellular degradation system that delivers cytoplasmic components to the lysosomes. It plays a wide variety of physiological and pathophysiological roles. The optineurin protein is a selective autophagy receptor (or adaptor), containing an ubiquitin binding domain with the ability to bind polyubiquitinated cargoes and bring them to autophagosomes via its microtubule-associated protein 1 light chain 3-interacting domain. It is involved in xenophagy, mitophagy, aggrephagy, and tumor suppression. Optineurin can also mediate the removal of protein aggregates through an ubiquitin-independent mechanism. This protein in addition can induce autophagy upon overexpression or mutation. When overexpressed or mutated, the optineurin protein also serves as a substrate for autophagic degradation. In the present review, the multiple connections of optineurin to autophagy are highlighted.
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