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Iorio R, Petricca S, Mattei V, Delle Monache S. Horizontal mitochondrial transfer as a novel bioenergetic tool for mesenchymal stromal/stem cells: molecular mechanisms and therapeutic potential in a variety of diseases. J Transl Med 2024; 22:491. [PMID: 38790026 DOI: 10.1186/s12967-024-05047-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/29/2024] [Indexed: 05/26/2024] Open
Abstract
Intercellular mitochondrial transfer (MT) is a newly discovered form of cell-to-cell signalling involving the active incorporation of healthy mitochondria into stressed/injured recipient cells, contributing to the restoration of bioenergetic profile and cell viability, reduction of inflammatory processes and normalisation of calcium dynamics. Recent evidence has shown that MT can occur through multiple cellular structures and mechanisms: tunneling nanotubes (TNTs), via gap junctions (GJs), mediated by extracellular vesicles (EVs) and other mechanisms (cell fusion, mitochondrial extrusion and migrasome-mediated mitocytosis) and in different contexts, such as under physiological (tissue homeostasis and stemness maintenance) and pathological conditions (hypoxia, inflammation and cancer). As Mesenchimal Stromal/ Stem Cells (MSC)-mediated MT has emerged as a critical regulatory and restorative mechanism for cell and tissue regeneration and damage repair in recent years, its potential in stem cell therapy has received increasing attention. In particular, the potential therapeutic role of MSCs has been reported in several articles, suggesting that MSCs can enhance tissue repair after injury via MT and membrane vesicle release. For these reasons, in this review, we will discuss the different mechanisms of MSCs-mediated MT and therapeutic effects on different diseases such as neuronal, ischaemic, vascular and pulmonary diseases. Therefore, understanding the molecular and cellular mechanisms of MT and demonstrating its efficacy could be an important milestone that lays the foundation for future clinical trials.
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Affiliation(s)
- Roberto Iorio
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, Via Vetoio, 67100, L'Aquila, Italy
| | - Sabrina Petricca
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, Via Vetoio, 67100, L'Aquila, Italy
| | - Vincenzo Mattei
- Dipartimento di Scienze della Vita, Della Salute e delle Professioni Sanitarie, Link Campus University, Via del Casale di San Pio V 44, 00165, Rome, Italy.
| | - Simona Delle Monache
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, Via Vetoio, 67100, L'Aquila, Italy.
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Zhou X, Fang G, Zhang L. Optimization of murine retinal mitochondrial injury model. MethodsX 2022; 9:101701. [PMID: 35492209 PMCID: PMC9046943 DOI: 10.1016/j.mex.2022.101701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/08/2022] [Indexed: 11/30/2022] Open
Abstract
The retinal mitochondrial injury model in rat has been developed using the mitochondrial oxidative phosphorylation uncoupler, carbonylcyanide m-chlorophenyl hydrazine (CCCP). However, the CCCP-induced murine retinal mitochondrial injury model has not been reported. Here, the optimized conditions for the murine retinal mitochondrial injury model were established by intravitreal injection of different doses of CCCP (0, 2.5, 5, 7.5, 10, 12.5, 15 μg). Indeed, it has been reported that CCCP induces Opa1 cleavage and phosphorylation of ERK in cultured cells and rat retinas. Thus, we measured phosphorylated (p) -Erk and L/S-Opa1 following CCCP-induced retinal injury. Meanwhile, KW6002 (A2A receptor antagonist) pretreatment inhibited retinal injury induced by CCCP at 10 and 15 μg doses differently. Intravitreal injection of 10 μg doses of CCCP can induce apoptosis of retinal ganglion cells and decrease of retinal thickness, but intravitreal injection of 15 μg doses of CCCP is the appropriate dose to study the protective effect of A2A receptor. (1) Dose dependent effects of intravitreal injection of CCCP on the levels of L/S-Opa1 and p-Erk; (2) A2A receptor antagonist (KW6002) only inhibited the apoptosis of ganglion cells, but did not affect the thickness of retina with 10µg dosage of CCCP intravitreal injection; (3) A2A receptor antagonist (KW6002) inhibited the apoptosis of ganglion cells and increased the thickness of retina with 15µg dosage of CCCP intravitreal injection.
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Lyamzaev KG, Zinovkin RA, Chernyak BV. Extrusion of mitochondria: Garbage clearance or cell–cell communication signals? J Cell Physiol 2022; 237:2345-2356. [DOI: 10.1002/jcp.30711] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 01/25/2022] [Accepted: 02/21/2022] [Indexed: 12/13/2022]
Affiliation(s)
- Konstantin G. Lyamzaev
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
- The “Russian Clinical Research Center for Gerontology” of the Ministry of Healthcare of the Russian Federation Pirogov Russian National Research Medical University Moscow Russia
| | - Roman A. Zinovkin
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
| | - Boris V. Chernyak
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow Russia
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Fang G, Zhou Y, Zhou X, Zhou H, Ge YY, Luo S, Chen JF, Zhang L. The adenosine A 2A receptor antagonist protects against retinal mitochondrial injury in association with an altered network of competing endogenous RNAs. Neuropharmacology 2022; 208:108981. [PMID: 35149135 DOI: 10.1016/j.neuropharm.2022.108981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/27/2022] [Accepted: 01/31/2022] [Indexed: 10/19/2022]
Abstract
Blockade of adenosine A2A receptors (A2ARs) protects against neuronal damage caused by various brain insults including mitochondrial toxicity, but the precise neuroprotective mechanisms are unclear. Here, we studied the effects of the A2AR antagonist KW6002 on retinal injury induced by the mitochondrial oxidative phosphorylation uncoupler, carbonylcyanide m-chlorophenyl hydrazine (CCCP) and alterations in competing endogenous RNA (ceRNA) network. We found that KW6002 treatment partially reversed CCCP-induced reduction in retinal thickness and retinal ganglia cell number by increasing mitochondrial content and reducing retinal ganglia cells apoptosis. Furthermore, we employed whole-transcriptome sequencing to explore ceRNA network changes associated with CCCP-induced retinal injury and its reversal by KW6002. This analysis revealed that A2AR blockade reduced the number of CCCP-induced microRNAs by ∼60%, but increased the number of CCCP-induced circular RNAs by ∼50%. Among CeRNA network changes, CCCP-induced retinal injury was associated with a possible enrichment of the tumor necrosis factor signaling pathway and its related 126 microRNAs, 237 long non-coding RNAs, 58 circular RNAs competing. Moreover, the A2AR antagonist-mediated protection against CCCP-induced retinal injury was possibly associated with the up-regulation of mature brain-derived neurotrophic factor and its related 4 microRNAs competed by 43 long non-coding RNAs and 9 circular RNAs competing. These ceRNA network alterations by CCCP treatment and its reversal by A2AR antagonist may contribute to understanding the transcriptome mechanism for protection against CCCP-induced retinal injury by A2AR antagonists.
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Affiliation(s)
- Gengjing Fang
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China
| | - Yuling Zhou
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China
| | - Xiaopeng Zhou
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China
| | - Hui Zhou
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China
| | - Yuan-Yuan Ge
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China
| | - Shengtao Luo
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China
| | - Jiang-Fan Chen
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China.
| | - Liping Zhang
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, 325000, China.
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Abstract
In 1999 V. P. Skulachev proposed the term "mitoptosis" to refer to the programmed elimination of mitochondria in living cells. According to the initial thought, mitoptosis serves to protect cells from malfunctioning of the damaged mitochondria. At the same time, a new mechanism of the complete mitochondria elimination was found under the conditions of massive mitochondrial damage associated with oxidative stress. In this experimental model, mitochondrial cluster formation in the perinuclear region leads to the formation of "mitoptotic body" surrounded by a single-layer membrane and subsequent release of mitochondria from the cell. Later, it was found that mitoptosis plays an important role in various normal and pathological processes that are not necessarily associated with the mitochondrial damage. It was found that mitoptosis takes place during cell differentiation, self-maintenance of hematopoietic stem cells, metabolic remodelling, and elimination of the paternal mitochondria in organisms with the maternal inheritance of the mitochondrial DNA. Moreover, the associated with mitoptosis release of mitochondrial components into the blood may be involved in the transmission of signals between cells, but also leads to the development of inflammatory and autoimmune diseases. Mitoptosis can be attributed to the asymmetric inheritance of mitochondria in the division of yeast and some animal cells, when the defective mitochondria are transferred to one of the newly formed cells. Finally, a specific form of mitoptosis appears to be selective elimination of mitochondria with deleterious mutations in whole follicular ovarian cells in mammals. During formation of the primary follicle, the mitochondrial DNA copy number is significantly reduced. After division, the cells that receive predominantly mitochondria with deleterious mutations in their mtDNA die, thereby reducing the likelihood of transmission of these mutations to offspring. Further study of the mechanisms of mitoptosis in normal and pathological conditions is important both for understanding the processes of development and aging, and for designing therapeutic approaches for inflammatory, neurodegenerative and other diseases.
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Affiliation(s)
- K G Lyamzaev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - D A Knorre
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - B V Chernyak
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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Kondadi AK, Anand R, Reichert AS. Functional Interplay between Cristae Biogenesis, Mitochondrial Dynamics and Mitochondrial DNA Integrity. Int J Mol Sci 2019; 20:ijms20174311. [PMID: 31484398 PMCID: PMC6747513 DOI: 10.3390/ijms20174311] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are vital cellular organelles involved in a plethora of cellular processes such as energy conversion, calcium homeostasis, heme biogenesis, regulation of apoptosis and ROS reactive oxygen species (ROS) production. Although they are frequently depicted as static bean-shaped structures, our view has markedly changed over the past few decades as many studies have revealed a remarkable dynamicity of mitochondrial shapes and sizes both at the cellular and intra-mitochondrial levels. Aberrant changes in mitochondrial dynamics and cristae structure are associated with ageing and numerous human diseases (e.g., cancer, diabetes, various neurodegenerative diseases, types of neuro- and myopathies). Another unique feature of mitochondria is that they harbor their own genome, the mitochondrial DNA (mtDNA). MtDNA exists in several hundreds to thousands of copies per cell and is arranged and packaged in the mitochondrial matrix in structures termed mt-nucleoids. Many human diseases are mechanistically linked to mitochondrial dysfunction and alteration of the number and/or the integrity of mtDNA. In particular, several recent studies identified remarkable and partly unexpected links between mitochondrial structure, fusion and fission dynamics, and mtDNA. In this review, we will provide an overview about these recent insights and aim to clarify how mitochondrial dynamics, cristae ultrastructure and mtDNA structure influence each other and determine mitochondrial functions.
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Affiliation(s)
- Arun Kumar Kondadi
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
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Martinez-Arroyo O, Gruevska A, Victor VM, González-Polo RA, Yakhine-Diop SM, Fuentes JM, Esplugues JV, Blas-Garcia A, Apostolova N. Mitophagy in human astrocytes treated with the antiretroviral drug Efavirenz: Lack of evidence or evidence of the lack. Antiviral Res 2019; 168:36-50. [DOI: 10.1016/j.antiviral.2019.04.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 04/11/2019] [Accepted: 04/30/2019] [Indexed: 01/19/2023]
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Kane MS, Paris A, Codron P, Cassereau J, Procaccio V, Lenaers G, Reynier P, Chevrollier A. Current mechanistic insights into the CCCP-induced cell survival response. Biochem Pharmacol 2017; 148:100-110. [PMID: 29277693 DOI: 10.1016/j.bcp.2017.12.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/20/2017] [Indexed: 01/13/2023]
Abstract
The ring-substituted derivatives of carbonyl cyanide phenylhydrazone, CCCP and FCCP, are routinely used for the analysis of the mitochondrial function in living cells, tissues, and isolated mitochondrial preparations. CCCP and FCCP are now being increasingly used for investigating the mechanisms of autophagy by inducing mitochondrial degradation through the disruption of the mitochondrial membrane potential (ΔΨm). Sustained perturbation of ΔΨm, which is normally tightly controlled to ensure cell proliferation and survival, triggers various stress pathways as part of the cellular adaptive response, the main components of which are mitophagy and autophagy. We here review current mechanistic insights into the induction of mitophagy and autophagy by CCCP and FCCP. In particular, we analyze the cellular modifications produced by the activation of two major pathways involving the signaling of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the transcription factor EB (TFEB), and discuss the contribution of these pathways to the integrated cellular stress response.
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Affiliation(s)
- Mariame Selma Kane
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Aurelien Paris
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Philippe Codron
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Julien Cassereau
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Vincent Procaccio
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Guy Lenaers
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Pascal Reynier
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France
| | - Arnaud Chevrollier
- MitoLab, Mitochondrial Medicine Research Centre, UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, 49933 Angers, France.
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Zimmermann M, Reichert AS. How to get rid of mitochondria: crosstalk and regulation of multiple mitophagy pathways. Biol Chem 2017; 399:29-45. [PMID: 28976890 DOI: 10.1515/hsz-2017-0206] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
Mitochondria are indispensable cellular organelles providing ATP and numerous other essential metabolites to ensure cell survival. Reactive oxygen species (ROS), which are formed as side reactions during oxidative phosphorylation or by external agents, induce molecular damage in mitochondrial proteins, lipids/membranes and DNA. To cope with this and other sorts of organellar stress, a multi-level quality control system exists to maintain cellular homeostasis. One critical level of mitochondrial quality control is the removal of damaged mitochondria by mitophagy. This process utilizes parts of the general autophagy machinery, e.g. for the formation of autophagosomes but also employs mitophagy-specific factors. Depending on the proteins utilized mitophagy is divided into receptor-mediated and ubiquitin-mediated mitophagy. So far, at least seven receptor proteins are known to be required for mitophagy under different experimental conditions. In contrast to receptor-mediated pathways, the Pink-Parkin-dependent pathway is currently the best characterized ubiquitin-mediated pathway. Recently two additional ubiquitin-mediated pathways with distinctive similarities and differences were unraveled. We will summarize the current state of knowledge about these multiple pathways, explain their mechanism, and describe the regulation and crosstalk between these pathways. Finally, we will review recent evidence for the evolutionary conservation of ubiquitin-mediated mitophagy pathways.
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Affiliation(s)
- Marcel Zimmermann
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, D-40225 Düsseldorf, Germany
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Czyż DM, Willett JW, Crosson S. Brucella abortus Induces a Warburg Shift in Host Metabolism That Is Linked to Enhanced Intracellular Survival of the Pathogen. J Bacteriol 2017; 199:e00227-17. [PMID: 28559292 DOI: 10.1128/JB.00227-17] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/18/2017] [Indexed: 01/29/2023] Open
Abstract
Intracellular bacterial pathogens exploit host cell resources to replicate and survive inside the host. Targeting these host systems is one promising approach to developing novel antimicrobials to treat intracellular infections. We show that human macrophage-like cells infected with Brucella abortus undergo a metabolic shift characterized by attenuated tricarboxylic acid cycle metabolism, reduced amino acid consumption, altered mitochondrial localization, and increased lactate production. This shift to an aerobic glycolytic state resembles the Warburg effect, a change in energy production that is well described in cancer cells and also occurs in activated inflammatory cells. B. abortus efficiently uses lactic acid as its sole carbon and energy source and requires the ability to metabolize lactate for normal survival in human macrophage-like cells. We demonstrate that chemical inhibitors of host glycolysis and lactate production do not affect in vitro growth of B. abortus in axenic culture but decrease its survival in the intracellular niche. Our data support a model in which infection shifts host metabolism to a Warburg-like state, and B. abortus uses this change in metabolism to promote intracellular survival. Pharmacological perturbation of these features of host cell metabolism may be a useful strategy to inhibit infection by intracellular pathogens.IMPORTANCEBrucella spp. are intracellular bacterial pathogens that cause disease in a range of mammals, including livestock. Transmission from livestock to humans is common and can lead to chronic human disease. Human macrophage-like cells infected with Brucella abortus undergo a Warburg-like metabolic shift to an aerobic glycolytic state where the host cells produce lactic acid and have reduced amino acid catabolism. We provide evidence that the pathogen can exploit this change in host metabolism to support growth and survival in the intracellular niche. Drugs that inhibit this shift in host cell metabolism inhibit intracellular replication and decrease the survival of B. abortus in an in vitro infection model; these drugs may be broadly useful therapeutics for intracellular infections.
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Zuo W, Zhang S, Xia CY, Guo XF, He WB, Chen NH. Mitochondria autophagy is induced after hypoxic/ischemic stress in a Drp1 dependent manner: the role of inhibition of Drp1 in ischemic brain damage. Neuropharmacology 2014; 86:103-15. [PMID: 25018043 DOI: 10.1016/j.neuropharm.2014.07.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/24/2014] [Accepted: 07/01/2014] [Indexed: 02/01/2023]
Abstract
Mitochondria dysfunction is implicated in diverse conditions, including metabolic and neurodegenerative disorders. Mitochondrial dynamics has attracted increasing attention as to its relationship with mitochondria autophagy, also known as mitophagy, which is critical for degradation of dysfunctional mitochondria maintaining mitochondrial homeostasis. Mitochondrial fission and its role in clearance of injured mitochondria in acute ischemic injury, however, have not been elucidated yet. Here we showed that hypoxic/ischemic conditions led to fragmentation of mitochondria and induction of mitophagy in permanent middle cerebral artery occlusion (pMCAO) rats and oxygen-glucose deprivation (OGD) PC12 cells. Inhibition of Drp1 by pharmacologic inhibitor or siRNA resulted in accumulation of damaged mitochondria mainly through selectively blocking mitophagy without affecting mitochondrial biogenesis and non-selective autophagy. Drp1 inhibitors increased the infarct volume and aggravated the neurological deficits in a rat model of pMCAO. We demonstrated that the devastating role of disturbed mitochondrial fission by inhibiting Drp1 contributed to the damaged mitochondria-mediated injury such as ROS generation, cyt-c release and activation of caspase-3. Taken together, we proved that under hypoxic/ischemic stress a Drp1-dependent mitophagy was triggered which was involved in the removal of damaged mitochondria and cellular survival at the early stage of hypoxic/ischemic injury. Thus, Drp1 related pathway involved in selective removal of dysfunctional mitochondria is proposed as an efficient target for treatment of cerebral ischemia.
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Affiliation(s)
- Wei Zuo
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, and Neuroscience Center, Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shuai Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, and Neuroscience Center, Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Cong-Yuan Xia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, and Neuroscience Center, Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xiao-Feng Guo
- Shanxi University of Traditional Chinese Medicine, Taiyuan 030024, China
| | - Wen-Bin He
- Shanxi University of Traditional Chinese Medicine, Taiyuan 030024, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, and Neuroscience Center, Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
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12
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Figge MT, Osiewacz HD, Reichert AS. Quality control of mitochondria during aging: is there a good and a bad side of mitochondrial dynamics? Bioessays 2013; 35:314-22. [PMID: 23359437 DOI: 10.1002/bies.201200125] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Maintenance of functional mitochondria is essential in order to prevent degenerative processes leading to disease and aging. Mitochondrial dynamics plays a crucial role in ensuring mitochondrial quality but may also generate and spread molecular damage through a population of mitochondria. Computational simulations suggest that this dynamics is advantageous when mitochondria are not or only marginally damaged. In contrast, at a higher degree of damage, mitochondrial dynamics may be disadvantageous. Deceleration of fusion-fission cycles could be one way to adapt to this situation and to delay a further decline in mitochondrial quality. However, this adaptive response makes the mitochondrial network more vulnerable to additional molecular damage. The "mitochondrial infectious damage adaptation" (MIDA) model explains a number of inconsistent and counterintuitive data such as the "clonal expansion" of mutant mitochondrial DNA. We propose that mitochondrial dynamics is a double-edged sword and suggest ways to test this experimentally.
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Affiliation(s)
- Marc Thilo Figge
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz-Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute and Friedrich Schiller University, Jena, Germany.
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13
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Galloway CA, Yoon Y. Perspectives on: SGP symposium on mitochondrial physiology and medicine: what comes first, misshape or dysfunction? The view from metabolic excess. ACTA ACUST UNITED AC 2013; 139:455-63. [PMID: 22641640 PMCID: PMC3362522 DOI: 10.1085/jgp.201210771] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Chad A Galloway
- Department of Anesthesiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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14
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Frank M, Duvezin-Caubet S, Koob S, Occhipinti A, Jagasia R, Petcherski A, Ruonala MO, Priault M, Salin B, Reichert AS. Mitophagy is triggered by mild oxidative stress in a mitochondrial fission dependent manner. Biochim Biophys Acta 2012; 1823:2297-310. [PMID: 22917578 DOI: 10.1016/j.bbamcr.2012.08.007] [Citation(s) in RCA: 324] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 08/06/2012] [Accepted: 08/07/2012] [Indexed: 12/16/2022]
Abstract
Mitochondrial dysfunction is linked to apoptosis, aging, cancer, and a number of neurodegenerative and muscular disorders. The interplay between mitophagy and mitochondrial dynamics has been linked to the removal of dysfunctional mitochondria ensuring mitochondrial quality control. An open question is what role mitochondrial fission plays in the removal of mitochondria after mild and transient oxidative stress; conditions reported to result in moderately elevated reactive oxygen species (ROS) levels comparable to physical activity. Here we show that applying such conditions led to fragmentation of mitochondria and induction of mitophagy in mouse and human cells. These conditions increased ROS levels only slightly and neither triggered cell death nor led to a detectable induction of non-selective autophagy. Starvation led to hyperfusion of mitochondria, to high ROS levels, and to the induction of both non-selective autophagy and to a lesser extent to mitophagy. We conclude that moderate levels of ROS specifically trigger mitophagy but are insufficient to trigger non-selective autophagy. Expression of a dominant-negative variant of the fission factor DRP1 blocked mitophagy induction by mild oxidative stress as well as by starvation. Taken together, we demonstrate that in mammalian cells under mild oxidative stress a DRP1-dependent type of mitophagy is triggered while a concomitant induction of non-selective autophagy was not observed. We propose that these mild oxidative conditions resembling well physiological situations are thus very helpful for studying the molecular pathways governing the selective removal of dysfunctional mitochondria.
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Affiliation(s)
- Magdalena Frank
- Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Germany
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15
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Mendl N, Occhipinti A, Müller M, Wild P, Dikic I, Reichert AS. Mitophagy in yeast is independent of mitochondrial fission and requires the stress response gene WHI2. J Cell Sci 2011; 124:1339-50. [PMID: 21429936 DOI: 10.1242/jcs.076406] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Dysfunctional mitochondria show a reduced capacity for fusion and, as mitochondrial fission is maintained, become spatially separated from the intact network. By that mechanism, dysfunctional mitochondria have been proposed to be targeted for selective degradation by mitophagy, thereby providing a quality control system for mitochondria. In yeast, conflicting results concerning the role of mitochondrial dynamics in mitophagy have been reported. Here, we investigate the effects on mitophagy of altering mitochondrial fission and fusion, using biochemical, as well as fluorescence-based, assays. Rapamycin-induced mitophagy was shown to depend upon the autophagy-related proteins Atg11, Atg20 and Atg24, confirming that a selective type of autophagy occurred. Both fragmentation of mitochondria and inhibition of oxidative phosphorylation were not sufficient to trigger mitophagy, and neither deletion of the fission factors Dnm1, Fis1, Mdv1 or Caf4 nor expression of dominant-negative variants of Dnm1 impaired mitophagy. The diminished mitophagy initially observed in a Δfis1 mutant was not due to the absence of Fis1 but rather due to a secondary mutation in WHI2, which encodes a factor reported to function in the general stress response and the Ras-protein kinase A (PKA) signaling pathway. We propose that, in yeast, mitochondrial fission is not a prerequisite for the selective degradation of mitochondria, and that mitophagy is linked to the general stress response and the Ras-PKA signaling pathway.
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Affiliation(s)
- Nadine Mendl
- Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5, 81377 München, Germany
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16
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Zanchetta LM, Garcia A, Lyng F, Walsh J, Murphy JEJ. Mitophagy and mitochondrial morphology in human melanoma-derived cells post exposure to simulated sunlight. Int J Radiat Biol 2011; 87:506-17. [PMID: 21381890 DOI: 10.3109/09553002.2011.556175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE To assess changes in mitochondrial morphology and mitophagy induced by simulated sunlight irradiation (SSI) and how these changes are modulated by mitochondrial activity and energy source. MATERIALS AND METHODS Human malignant amelanotic melanoma A375 cells were pre-treated with either a mitochondrial activity enhancer, uncoupler or were either melanin or glutamine supplemented/starved for 4 hours pre-exposure to sunlight. A Q-Sun Solar Simulator (Q-Lab, Homestead, FL, USA) was employed to expose cells to simulated sunlight. Confocal microscopy imaging of A375 cells co-loaded with mitochondria and lysosome-specific fluorescent dyes was used to identify these organelles and predict mitophagic events. RESULTS SSI induces pronounced changes in mitochondrial dynamics and mitophagy in exposed skin cells compared to control and these effects were modified by both glutamine and melanin. CONCLUSIONS Mitochondrial dynamics and rate of mitophagy in melanoma cells are sensitive to even short bursts of environmentally relevant SSI. Mitochondrial dynamics, and its modulation, may also play a role in mitophagy regulation, cell survival and proliferation post SSI.
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Affiliation(s)
- Luciene M Zanchetta
- Mitochondrial Biology & Radiation Research, School of Science, Institute of Technology Sligo, Ash Lane, Sligo, Ireland.
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17
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Abstract
Mitochondrial dynamics is a key feature for the interaction of mitochondria with other organelles within a cell and also for the maintenance of their own integrity. Four types of mitochondrial dynamics are discussed: Movement within a cell and interactions with the cytoskeleton, fusion and fission events which establish coherence within the chondriome, the dynamic behavior of cristae and their components, and finally, formation and disintegration of mitochondria (mitophagy). Due to these essential functions, disturbed mitochondrial dynamics are inevitably connected to a variety of diseases. Localized ATP gradients, local control of calcium-based messaging, production of reactive oxygen species, and involvement of other metabolic chains, that is, lipid and steroid synthesis, underline that physiology not only results from biochemical reactions but, in addition, resides on the appropriate morphology and topography. These events and their molecular basis have been established recently and are the topic of this review.
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Affiliation(s)
- Jürgen Bereiter-Hahn
- Center of Excellence Macromolecular Complexes, Institute for Cell Biology and Neurosciences, Goethe University, Frankfurt am Main, Germany
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18
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Abstract
PURPOSE OF REVIEW To discuss novel developments related to the mechanisms of antiretroviral therapy-related mitochondrial toxicity, describe some apparent paradoxes in the current understanding of this field, and present questions that should be addressed by future research. RECENT FINDINGS The early polymerase gamma hypothesis states that nucleoside reverse transcriptase inhibitors can inhibit mitochondrial DNA replication and cause mitochondrial toxicity through mtDNA depletion. This mechanism is supported by a large body of evidence. Clinical manifestations of mitochondrial dysfunction are not always associated with mtDNA depletion. Increased mtDNA levels after nucleoside reverse transcriptase inhibitor exposure, as well as seemingly severe mtDNA depletion in individuals who show no clinical toxicity, have been reported. These and other observations suggest that additional mechanisms are involved in antiretroviral therapy toxicity, a notion supported by recent studies. Individuals given the same antiretroviral regimen can differ vastly with respect to the development of mitochondrial toxicity symptoms, reflecting interindividual variability. Some factors that may modulate this variability will be discussed. SUMMARY Mitochondrial toxicity induced by nucleoside reverse transcriptase inhibitors and their metabolic intermediates is probably mediated through many direct and indirect mechanisms. Depending on the mechanisms at play, the long-term health consequences of this toxicity may vary.
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19
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Abstract
Mitochondria are highly dynamic organelles forming a tubular network that is sustained by fusion and fission events. Impairment thereof leads to various neuropathies in humans, such as optic atrophy and Parkinson's disease. We have only begun to understand the molecular machineries facilitating fusion and fission of mitochondria and how these processes are regulated. The physiological role of mitochondrial dynamics and how it may be involved in maintaining mitochondrial functionality is still unclear. Here, we discuss current views in this emerging field focusing on the molecular basis of how mitochondrial morphology is regulated and how this may contribute to mitochondrial quality control.
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Affiliation(s)
- Anja Schäfer
- CEF Makromolekulare Komplexe, Mitochondriale Biologie, Fachbereich Medizin, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, D-60590 Frankfurt/Main, Germany
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20
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Abstract
The recently ascertained network and dynamic organization of the mitochondrion, as well as the demonstration of energy proteins and metabolites subcompartmentalization, have led to a reconsideration of the relationships between organellar form and function. In particular, the impact of mitochondrial morphological changes on bioenergetics is inseparable. Several observations indicate that mitochondrial energy production may be controlled by structural rearrangements of the organelle both interiorly and globally, including the remodeling of cristae morphology and elongation or fragmentation of the tubular network organization, respectively. These changes are mediated by fusion or fission reactions in response to physiological signals that remain unidentified. They lead to important changes in the internal diffusion of energy metabolites, the sequestration and conduction of the electric membrane potential (Delta Psi), and possibly the delivery of newly synthesized ATP to various cellular areas. Moreover, the physiological or even pathological context also determines the morphology of the mitochondrion, suggesting a tight and mutual control between mitochondrial form and bioenergetics. In this review, we delve into the link between mitochondrial structure and energy metabolism.
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21
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Lyamzaev KG, Nepryakhina OK, Saprunova VB, Bakeeva LE, Pletjushkina OY, Chernyak BV, Skulachev VP. Novel mechanism of elimination of malfunctioning mitochondria (mitoptosis): Formation of mitoptotic bodies and extrusion of mitochondrial material from the cell. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2008; 1777:817-25. [DOI: 10.1016/j.bbabio.2008.03.027] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 03/04/2008] [Accepted: 03/26/2008] [Indexed: 11/25/2022]
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22
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Côté HCF, Day AG, Heyland DK. Longitudinal increases in mitochondrial DNA levels in blood cells are associated with survival in critically ill patients. Crit Care 2008; 11:R88. [PMID: 17697385 PMCID: PMC2206483 DOI: 10.1186/cc6096] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 08/10/2007] [Accepted: 08/15/2007] [Indexed: 12/26/2022]
Abstract
Background Mitochondrial dysfunction may be causally related to the pathogenesis of organ failure in critically ill patients. Decreased mitochondrial DNA (mtDNA) levels have been associated with mitochondrial dysfunction and were investigated here in relation to short-term (31-day) survival. Methods This was a prospective longitudinal cohort study of 28 mechanically ventilated critically ill adults admitted to a single center tertiary care intensive care unit (ICU) with hypotension secondary to cardiogenic (N = 13), septic (N = 14) or hypovolemic (N = 1) disease processes. Clinical data and blood were collected at baseline and patients were followed until they expired or left the ICU. Blood was collected every Monday, Wednesday and Friday, and the buffycoat relative mtDNA/nuclear DNA (nDNA) ratio was determined. An archived pool of healthy controls was also studied. Results At baseline, the patients' mtDNA/nDNA ratio was 30% lower than a pool of 24 healthy controls (0.76 versus 1.09) and was not different between short-term survivors and non-survivors (0.74 ± 0.05 (N = 16) versus 0.79 ± 0.06 (N = 12), p = 0.49). By day 4, the percent mtDNA/nDNA change from baseline in survivors was significantly different from that in non-survivors (+29.5% versus -5.7%, p = 0.03). It also tended to be higher in survivors at last measurement (+38.4% versus +7.1%, p = 0.06). There was a weak correlation between within patient mtDNA/nDNA and platelet count (r = 0.20, p = 0.03) but not with Sequential Organ Failure Assessment (SOFA) scores (r = 0.12, p = 0.23). The mtDNA associations remained after adjustment for platelet. Conclusion Blood mtDNA levels appeared initially low, increased over time in patients who ultimately survived, and remained low in those who did not. This is consistent with mitochondrial recovery being associated with survival and warrants further investigation as a marker of mitochondrial alterations and outcome in critical illness.
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Affiliation(s)
- Hélène CF Côté
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada V6T 2B5
| | - Andrew G Day
- Clinical Research Centre, Kingston General Hospital, Kingston, Canada K7L 2V7
| | - Daren K Heyland
- Department of Medicine, Queen's University and Critical Care Program, Kingston General Hospital, Kingston, Canada K7L 2V7
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23
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Benard G, Bellance N, James D, Parrone P, Fernandez H, Letellier T, Rossignol R. Mitochondrial bioenergetics and structural network organization. J Cell Sci 2007; 120:838-48. [PMID: 17298981 DOI: 10.1242/jcs.03381] [Citation(s) in RCA: 455] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mitochondria form a dynamic network, and it remains unclear how the alternate configurations interact with bioenergetics properties. The metabolic signals that link mitochondrial structure to its functional states have not been fully characterized. In this report, we analyze the bidirectional relationships between mitochondrial morphology and function in living human cells. First, we determined the effect of mitochondrial fission on energy production by using small interfering RNA (siRNA) targeting DRP1, which revealed the importance of membrane fluidity on the control of bioenergetics. Second, we followed the effect of rotenone, a specific inhibitor of respiratory chain complex I, which causes large structural perturbations, once a threshold was reached. Last, we followed changes in the mitochondrial network configuration in human cells that had been treated with modulators of oxidative phosphorylation, and in fibroblasts from two patients with mitochondrial disease where the respiratory rate, ΔΨ and the generation of reactive oxygen species (ROS) were measured. Our data demonstrate that the relationship between mitochondrial network organization and bioenergetics is bidirectional, and we provide a model for analyzing the metabolic signals involved in this crosstalk.
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Affiliation(s)
- Giovanni Benard
- Institut National de la Santé et de la Recherche Médicale (INSERM), U688 Physiopathologie Mitochondriale, Universite Victor Segalen-Bordeaux 2, 146 rue Leo-Saignat, F-33076 Bordeaux cedex, France
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24
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Schick BA, Laaksonen R, Frohlich JJ, Päivä H, Lehtimäki T, Humphries KH, Côté HCF. Decreased Skeletal Muscle Mitochondrial DNA in Patients Treated with High-Dose Simvastatin. Clin Pharmacol Ther 2007; 81:650-3. [PMID: 17329991 DOI: 10.1038/sj.clpt.6100124] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Statins are generally well tolerated, but can cause myopathy and have been associated with mitochondrial abnormalities. The aim of this study was to determine whether muscle mitochondrial DNA (mtDNA) levels are altered during statin therapy. We retrospectively quantified mtDNA in 86 skeletal muscle biopsy specimens collected as part of a previously published clinical trial of high-dose simvastatin or atorvastatin versus placebo.
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Affiliation(s)
- B A Schick
- Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada, and Research Unit, Tampere University Hospital, Finland
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25
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Busch KB, Bereiter-Hahn J, Wittig I, Schagger H, Jendrach M. Mitochondrial dynamics generate equal distribution but patchwork localization of respiratory Complex I. Mol Membr Biol 2007; 23:509-20. [PMID: 17127623 DOI: 10.1080/09687860600877292] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Highly dynamic mitochondrial morphology is a prerequisite for fusion and fission. Mitochondrial fusion may represent a rescue mechanism for impaired mitochondria by exchanging constituents (proteins, lipids and mitochondrial DNA) and thus maintaining functionality. Here we followed for the first time the dynamics of a protein complex of the respiratory chain during fusion and fission. HeLa cells with differently labelled respiratory Complex I were fused and the dynamics of Complex I were investigated. The mitochondrial proteins spread throughout the whole mitochondrial population within 3 to 6 h after induction of cell fusion. Mitochondria of fused cells displayed a patchy substructure where the differently labelled proteins occupied separate and distinct spaces. This patchy appearance was already--although less pronounced--observed within single mitochondria before fusion, indicating a specific localization of Complex I with restricted diffusion within the inner membrane. These findings substantiate the view of a homogenous mitochondrial population due to constantly rearranging mitochondria, but also indicate the existence of distinct inner mitochondrial sub-compartments for respiratory chain complexes.
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Affiliation(s)
- Karin B Busch
- Kinematic Cell Research Group, Institute for Cell Biology and Neuroscience, JW Goethe University, Frankfurt/Main, Germany.
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26
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Abstract
Mitochondria are the key generators of cellular ATP, and contain extranuclear genome-mitochondrial DNA (mtDNA). In the process of nuclear transfer (NT), heteroplasmic sources of mtDNA from a donor cell and a recipient oocyte are mixed in the cytoplasm of the reconstituted embryo. Previous studies showed inconsistent patterns of mtDNA inheritance in offspring and early fetuses generated through interspecies NT. The quantitative analysis of mitochondrial RNA (mtRNA) in interspecies cloned embryos is useful for better understanding the fate of two types of mitochondria. The components of nicotinamide adenine dinucleotide (NADH) dehydrogenase were coded by both nuclear DNA (nDNA) and mtDNA. The Subunit 1 (ND-1) is one of seven NADH dehydrogenase subunits coded by mtDNA. In present study, using real-time and reverse-transcription PCR, the copy number of species-specific ND-1 mRNA was examined in goat-sheep cloned embryos of various developmental stages, and was applied to evaluate the expression pattern of species-specific mtDNA. The results of showed that (1) the expression of mtDNA derived from goat fetal fibroblast (GFF) decreased from 1-cell stage (immediately after fused) to 2-cell stage, and could not be detected from 4-cell stage onward to blastocyst stage; (2) the expression of mtDNA derived from sheep oocyte was roughly constant from 1-cell stage to the 8-cell stage, increased gradually from 16-cell stage, and sharply at morula and blastocyst stage. Moreover, we strongly argued a mechanism, that is GFF-derived mitochondria were degraded for the depression of bioenergetic functions, and then selectively eliminated during the embryogenesis of goat-sheep cloned embryos.
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Affiliation(s)
- Li-Bing Ma
- Institute of Biotechnology, Northwest A&F University, Yangling, Shaanxi, China
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27
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Labrador V, Fernández Freire P, Pérez Martín JM, Hazen MJ. Cytotoxicity of butylated hydroxyanisole in Vero cells. Cell Biol Toxicol 2006; 23:189-99. [PMID: 17149658 DOI: 10.1007/s10565-006-0153-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 10/11/2006] [Indexed: 10/23/2022]
Abstract
Butylated hydroxyanisole (BHA) is perhaps the most extensively used synthetic antioxidant in the food and cosmetic industry, although considerable controversy exists in the literature regarding the safety of this compound. Most in vitro studies describing the effects of BHA have been performed in cancer cells, but it is unclear whether normal cells are equally susceptible to BHA exposure. The present study investigate the toxic potential of BHA in mammalian cells, using biochemical and morphological parameters, which reveal interference with structures essential for cell survival, proliferation and/or function. Cell growth inhibition was assessed by using colorimetric assays, whereas cellular alterations after BHA exposure, were evaluated using conventional light and fluorescence microscopy. Low doses of BHA exerted a significant cytotoxic effect, associated with loss of mitochondrial function. As the concentration of BHA was increased, morphological alterations in critical subcellular targets such as lysosomes, mitochondria and actin cytoskeleton, were observed. In parallel, BHA induced an irreversible loss of cell proliferative capacity, preceding apoptosis induction. Thus, the dose-dependent activity of BHA on Vero cells appears to be cytotoxic as well as cytostatic. Our observations, although simplified with respect to the in vivo situations, allowed the assessment of the specific damage at the cellular level, and provide some clue about the effects of BHA in non-tumoral mammalian cells.
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Affiliation(s)
- V Labrador
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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28
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Duvezin-Caubet S, Jagasia R, Wagener J, Hofmann S, Trifunovic A, Hansson A, Chomyn A, Bauer MF, Attardi G, Larsson NG, Neupert W, Reichert AS. Proteolytic processing of OPA1 links mitochondrial dysfunction to alterations in mitochondrial morphology. J Biol Chem 2006; 281:37972-9. [PMID: 17003040 DOI: 10.1074/jbc.m606059200] [Citation(s) in RCA: 335] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Many muscular and neurological disorders are associated with mitochondrial dysfunction and are often accompanied by changes in mitochondrial morphology. Mutations in the gene encoding OPA1, a protein required for fusion of mitochondria, are associated with hereditary autosomal dominant optic atrophy type I. Here we show that mitochondrial fragmentation correlates with processing of large isoforms of OPA1 in cybrid cells from a patient with myoclonus epilepsy and ragged-red fibers syndrome and in mouse embryonic fibroblasts harboring an error-prone mitochondrial mtDNA polymerase gamma. Furthermore, processed OPA1 was observed in heart tissue derived from heart-specific TFAM knock-out mice suffering from mitochondrial cardiomyopathy and in skeletal muscles from patients suffering from mitochondrial myopathies such as myopathy encephalopathy lactic acidosis and stroke-like episodes. Dissipation of the mitochondrial membrane potential leads to fast induction of proteolytic processing of OPA1 and concomitant fragmentation of mitochondria. Recovery of mitochondrial fusion depended on protein synthesis and was accompanied by resynthesis of large isoforms of OPA1. Fragmentation of mitochondria was prevented by overexpressing OPA1. Taken together, our data indicate that proteolytic processing of OPA1 has a key role in inducing fragmentation of energetically compromised mitochondria. We present the hypothesis that this pathway regulates mitochondrial morphology and serves as an early response to prevent fusion of dysfunctional mitochondria with the functional mitochondrial network.
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Affiliation(s)
- Stéphane Duvezin-Caubet
- Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5, 81377 München, Germany
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29
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Abstract
In this review I summarize interrelations between bioenergetic processes and such programmed death phenomena as cell suicide (apoptosis and necrosis) and mitochondrial suicide (mitoptosis). The following conclusions are made. (I) ATP and rather often mitochondrial hyperpolarization (i.e. an increase in membrane potential, delta psi) are required for certain steps of apoptosis and necrosis. (II) Apoptosis, even if it is accompanied by delta psi and [ATP] increases at its early stage, finally results in a delta psi collapse and ATP decrease. (III) Moderate (about three-fold) lowering of [ATP] for short and long periods of time induces apoptosis and necrosis, respectively. In some types of apoptosis and necrosis, the cell death is mediated by a delta psi-dependent overproduction of ROS by the initial (Complex I) and the middle (Complex III) spans of the respiratory chain. ROS initiate mitoptosis which is postulated to rid the intracellular population of mitochondria from those that are ROS overproducing. Massive mitoptosis can result in cell death due to release to cytosol of the cell death proteins normally hidden in the mitochondrial intermembrane space.
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Affiliation(s)
- V P Skulachev
- Department of Bioenergetics, Belozersky Institute of Physico-Chemical Biology and School of Bioengineering and Bioinformatics, Moscow State University, Moscow, 119992, Russia.
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30
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Pletjushkina OY, Lyamzaev KG, Popova EN, Nepryakhina OK, Ivanova OY, Domnina LV, Chernyak BV, Skulachev VP. Effect of oxidative stress on dynamics of mitochondrial reticulum. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2006; 1757:518-24. [PMID: 16829229 DOI: 10.1016/j.bbabio.2006.03.018] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 02/28/2006] [Accepted: 03/17/2006] [Indexed: 10/24/2022]
Abstract
Fission of the mitochondrial reticulum (the thread-grain transition) and following gathering of mitochondria in the perinuclear area are induced by oxidative stress. It is shown that inhibitors of the respiratory chain (piericidin and myxothiazol) cause fission of mitochondria in HeLa cells and fibroblasts, whereas a mitochondria-targeted antioxidant (MitoQ) inhibits this effect. Hydrogen peroxide also induced the fission, which was stimulated by the inhibitors of respiration and suppressed by MitoQ. In untreated cells, the mitochondrial reticulum consisted of numerous electrically-independent fragments. Prolonged treatment with MitoQ resulted in drastic increase in size and decrease in number of these fragments. Local photodamage of mitochondria caused immediate depolarization of a large fraction of the mitochondrial network in MitoQ-treated cells. Our data indicate that the thread-grain transition of mitochondria depends on production of reactive oxygen species (ROS) in initial segments of the respiratory chain and is a necessary step in the process of elimination of mitochondria (mitoptosis).
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Affiliation(s)
- O Yu Pletjushkina
- A. N. Belozersky Institute, Moscow State University, 119992 Moscow, Russia.
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31
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Kuznetsov AV, Troppmair J, Sucher R, Hermann M, Saks V, Margreiter R. Mitochondrial subpopulations and heterogeneity revealed by confocal imaging: possible physiological role? Biochim Biophys Acta 2006; 1757:686-91. [PMID: 16712778 DOI: 10.1016/j.bbabio.2006.03.014] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/02/2006] [Revised: 02/16/2006] [Accepted: 03/16/2006] [Indexed: 11/23/2022]
Abstract
Heterogeneity of mitochondria has been reported for a number of various cell types. Distinct mitochondrial subpopulations may be present in the cell and may be differently involved in physiological and pathological processes. However, the origin and physiological roles of mitochondrial heterogeneity are still unknown. In mice skeletal muscle, a much higher oxidized state of subsarcolemmal mitochondria as compared with intermyofibrillar mitochondria has been demonstrated. Using confocal imaging technique, we present similar phenomenon for rat soleus and gastrocnemius muscles, where higher oxidative state of mitochondrial flavoproteins correlates also with elevated mitochondrial calcium. Moreover, subsarcolemmal mitochondria demonstrate distinct arrangement and organization. In HL-1 cardiomyocytes, long thread mitochondria and small grain mitochondria are observed irrespective of a particular cellular region, showing also heterogeneous membrane potential and ROS production. Possible physiological roles of intracellular mitochondrial heterogeneity and specializations are discussed.
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Affiliation(s)
- Andrey V Kuznetsov
- Daniel Swarovski Research Laboratory, Innsbruck Medical University, Innrain 66, A-6020 Innsbruck, Austria.
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32
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Roumier T, Szabadkai G, Simoni AM, Perfettini JL, Paulau AL, Castedo M, Métivier D, Badley A, Rizzuto R, Kroemer G. HIV-1 protease inhibitors and cytomegalovirus vMIA induce mitochondrial fragmentation without triggering apoptosis. Cell Death Differ 2006; 13:348-51. [PMID: 16123780 DOI: 10.1038/sj.cdd.4401750] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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