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Lin YH, Lin KL, Wang XW, Lee JJ, Wang FS, Wang PW, Lan MY, Liou CW, Lin TK. Miro1 improves the exogenous engraftment efficiency and therapeutic potential of mitochondria transfer using Wharton's jelly mesenchymal stem cells. Mitochondrion 2024; 76:101856. [PMID: 38408618 DOI: 10.1016/j.mito.2024.101856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 02/08/2024] [Accepted: 02/22/2024] [Indexed: 02/28/2024]
Abstract
Mitochondria are important for maintaining cellular energy metabolism and regulating cellular senescence. Mitochondrial DNA (mtDNA) encodes subunits of the OXPHOS complexes which are essential for cellular respiration and energy production. Meanwhile, mtDNA variants have been associated with the pathogenesis of neurodegenerative diseases, including MELAS, for which no effective treatment has been developed. To alleviate the pathological conditions involved in mitochondrial disorders, mitochondria transfer therapy has shown promise. Wharton's jelly mesenchymal stem cells (WJMSCs) have been identified as suitable mitochondria donors for mitochondria-defective cells, wherein mitochondrial functions can be rescued. Miro1 participates in mitochondria trafficking by anchoring mitochondria to microtubules. In this study, we identified Miro1 over-expression as a factor that could help to enhance the efficiency of mitochondrial delivery. More specifically, we reveal that Miro1 over-expressed WJMSCs significantly improved intercellular communications, cell proliferation rates, and mitochondrial membrane potential, while restoring mitochondrial bioenergetics in mitochondria-defective fibroblasts. Furthermore, Miro1 over-expressed WJMSCs decreased rates of induced apoptosis and ROS production in MELAS fibroblasts; although, Miro1 over-expression did not rescue mtDNA mutation ratios nor mitochondrial biogenesis. This study presents a potentially novel therapeutic strategy for treating mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), and other diseases associated with dysfunctional mitochondria, while the pathophysiological relevance of our results should be further verified by animal models and clinical studies.
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Affiliation(s)
- Yu-Han Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan.
| | - Kai-Lieh Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 833401, Taiwan.
| | - Xiao-Wen Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan.
| | - Jong-Jer Lee
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 833401, Taiwan.
| | - Feng-Sheng Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; Core Laboratory for Phenomics and Diagnostics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan.
| | - Pei-Wen Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; Department of Metabolism, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 833401, Taiwan.
| | - Min-Yu Lan
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 833401, Taiwan; Center of Parkinson's Disease, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan.
| | - Chia-Wei Liou
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 833401, Taiwan.
| | - Tsu-Kung Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833401, Taiwan; School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 833401, Taiwan.
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Colpman P, Dasgupta A, Archer SL. The Role of Mitochondrial Dynamics and Mitotic Fission in Regulating the Cell Cycle in Cancer and Pulmonary Arterial Hypertension: Implications for Dynamin-Related Protein 1 and Mitofusin2 in Hyperproliferative Diseases. Cells 2023; 12:1897. [PMID: 37508561 PMCID: PMC10378656 DOI: 10.3390/cells12141897] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Mitochondria, which generate ATP through aerobic respiration, also have important noncanonical functions. Mitochondria are dynamic organelles, that engage in fission (division), fusion (joining) and translocation. They also regulate intracellular calcium homeostasis, serve as oxygen-sensors, regulate inflammation, participate in cellular and organellar quality control and regulate the cell cycle. Mitochondrial fission is mediated by the large GTPase, dynamin-related protein 1 (Drp1) which, when activated, translocates to the outer mitochondrial membrane (OMM) where it interacts with binding proteins (Fis1, MFF, MiD49 and MiD51). At a site demarcated by the endoplasmic reticulum, fission proteins create a macromolecular ring that divides the organelle. The functional consequence of fission is contextual. Physiological fission in healthy, nonproliferating cells mediates organellar quality control, eliminating dysfunctional portions of the mitochondria via mitophagy. Pathological fission in somatic cells generates reactive oxygen species and triggers cell death. In dividing cells, Drp1-mediated mitotic fission is critical to cell cycle progression, ensuring that daughter cells receive equitable distribution of mitochondria. Mitochondrial fusion is regulated by the large GTPases mitofusin-1 (Mfn1) and mitofusin-2 (Mfn2), which fuse the OMM, and optic atrophy 1 (OPA-1), which fuses the inner mitochondrial membrane. Mitochondrial fusion mediates complementation, an important mitochondrial quality control mechanism. Fusion also favors oxidative metabolism, intracellular calcium homeostasis and inhibits cell proliferation. Mitochondrial lipids, cardiolipin and phosphatidic acid, also regulate fission and fusion, respectively. Here we review the role of mitochondrial dynamics in health and disease and discuss emerging concepts in the field, such as the role of central versus peripheral fission and the potential role of dynamin 2 (DNM2) as a fission mediator. In hyperproliferative diseases, such as pulmonary arterial hypertension and cancer, Drp1 and its binding partners are upregulated and activated, positing mitochondrial fission as an emerging therapeutic target.
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Affiliation(s)
- Pierce Colpman
- Department of Medicine, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Asish Dasgupta
- Department of Medicine, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Stephen L Archer
- Department of Medicine, Queen's University, Kingston, ON K7L 3N6, Canada
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3
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Liu Q, Weng J, Li C, Feng Y, Xie M, Wang X, Chang Q, Li M, Chung KF, Adcock IM, Huang Y, Zhang H, Li F. Attenuation of PM 2.5-induced alveolar epithelial cells and lung injury through regulation of mitochondrial fission and fusion. Part Fibre Toxicol 2023; 20:28. [PMID: 37464447 DOI: 10.1186/s12989-023-00534-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 06/05/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Exposure to particulate matter (PM) with an aerodynamic diameter less than 2.5 μm (PM2.5) is a risk factor for developing pulmonary diseases and the worsening of ongoing disease. Mitochondrial fission and fusion are essential processes underlying mitochondrial homeostasis in health and disease. We examined the role of mitochondrial fission and fusion in PM2.5-induced alveolar epithelial cell damage and lung injury. Key genes in these processes include dystrophin-related protein 1 (DRP1) and optic atrophy 1 (OPA1) respectively. METHODS Alveolar epithelial (A549) cells were treated with PM2.5 (32 µg/ml) in the presence and absence of Mdivi-1 (10µM, a DRP1 inhibitor) or BGP-15 (10µM, an OPA1 activator). Results were validated using DRP1-knockdown (KD) and OPA1-overexpression (OE). Mice were injected intraperitoneally with Mdivi-1 (20 mg/kg), BGP-15 (20 mg/kg) or distilled water (control) one hour before intranasal instillation of PM2.5 (7.8 mg/kg) or distilled water for two consecutive days. RESULTS PM2.5 exposure of A549 cells caused oxidative stress, enhanced inflammation, necroptosis, mitophagy and mitochondrial dysfunction indicated by abnormal mitochondrial morphology, decreased mitochondrial membrane potential (ΔΨm), reduced mitochondrial respiration and disrupted mitochondrial fission and fusion. Regulating mitochondrial fission and fusion pharmacologically using Mdivi-1 and BGP-15 and genetically using DRP1-KD and OPA1-OE prevented PM2.5-induced celluar damage in A549 cells. Mdivi-1 and BGP-15 attenuated PM2.5-induced acute lung injury in mice. CONCLUSION Increased mitochondrial fission and decreased mitochondrial fusion may underlie PM2.5-induced alveolar epithelial cell damage in vitro and lung injury in vivo.
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Affiliation(s)
- Qi Liu
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Jiali Weng
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Chenfei Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Yi Feng
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Meiqin Xie
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Xiaohui Wang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Qing Chang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Mengnan Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China
| | - Kian Fan Chung
- Airway Disease Section, National Heart and Lung Institute, Imperial College, Dovehouse Street, SW3 6LY, London, UK
| | - Ian M Adcock
- Airway Disease Section, National Heart and Lung Institute, Imperial College, Dovehouse Street, SW3 6LY, London, UK
| | - Yan Huang
- School of Pharmacy, Anhui Medical University, 230022, Hefei, Anhui, China
| | - Hai Zhang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China.
| | - Feng Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University School of medicine, NO.241, West Huaihai Road, 200030, Shanghai, P.R. China.
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4
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Hata Y, Ichimata S, Hirono K, Yamaguchi Y, Oku Y, Ichida F, Nishida N. Pathological and Comprehensive Genetic Investigation of Autopsy Cases of Idiopathic Bradyarrhythmia. Circ J 2022; 87:111-119. [PMID: 36070930 DOI: 10.1253/circj.cj-22-0397] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Idiopathic bradyarrhythmia is considered to be due to pathological degeneration of the cardiac conduction system (CCS) during aging. There appears to have been no comprehensive genetic investigations in patients with idiopathic bradyarrhythmia. METHODS AND RESULTS Ten autopsy cases with advanced bradyarrhythmia (6 men and 4 women; age: 70-94 years, 81.5±6.9 years; 5 cases each of sinus node dysfunction [SND] and complete atrioventricular block [CAVB]) were genetically investigated by using whole-exome sequencing. Morphometric analysis of the CCS was performed with sex-, age- and comorbidity-matched control cases. As a result, severe loss of nodal cells and distal atrioventricular conduction system were found in SND and CAVB, respectively. However, the conduction tissue loss was not significant in either the atrioventricular node or the proximal bundle of His in CAVB cases. A total of 13 heterozygous potential variants were found in 3 CAVB and 2 SND cases. Of these 13 variants, 4 were missense in the known progressive cardiac conduction disease-related genes: GATA4 and RYR2. In the remaining 9 variants, 5 were loss-of-function mutation with highly possible pathogenicity. CONCLUSIONS In addition to degenerative changes of selectively vulnerable areas in the heart during advancing age, the vulnerability of the CCS, which may be associated with "rare variants of small effect," may also be a contributing factor to the degeneration of CCS, leading to "idiopathic" bradyarrhythmia.
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Affiliation(s)
- Yukiko Hata
- Department of Legal Medicine, Faculty of Medicine, University of Toyama
| | - Shojiro Ichimata
- Department of Legal Medicine, Faculty of Medicine, University of Toyama
| | - Keiichi Hirono
- Department of Pediatrics, Faculty of Medicine, University of Toyama
| | - Yoshiaki Yamaguchi
- Department of Legal Medicine, Faculty of Medicine, University of Toyama
- Department of Cardiology, Saiseikai Takaoka Hospital
| | - Yuko Oku
- Department of Legal Medicine, Faculty of Medicine, University of Toyama
| | - Fukiko Ichida
- Department of Pediatrics, International University of Health & Welfare
| | - Naoki Nishida
- Department of Legal Medicine, Faculty of Medicine, University of Toyama
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5
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Kim JS, Chapman WC, Lin Y. Mitochondrial Autophagy in Ischemic Aged Livers. Cells 2022; 11:cells11244083. [PMID: 36552847 PMCID: PMC9816943 DOI: 10.3390/cells11244083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial autophagy (mitophagy) is a central catabolic event for mitochondrial quality control. Defective or insufficient mitophagy, thus, can result in mitochondrial dysfunction, and ultimately cell death. There is a strong causal relationship between ischemia/reperfusion (I/R) injury and mitochondrial dysfunction following liver resection and transplantation. Compared to young patients, elderly patients poorly tolerate I/R injury. Accumulation of abnormal mitochondria after I/R is more prominent in aged livers than in young counterparts. This review highlights how altered autophagy is mechanistically involved in age-dependent hypersensitivity to reperfusion injury.
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Affiliation(s)
- Jae-Sung Kim
- Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA; (W.C.C.); (Y.L.)
- Department of Cell Biology & Physiology, Washington University in St. Louis, St. Louis, MO 63110, USA
- Correspondence:
| | - William C. Chapman
- Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA; (W.C.C.); (Y.L.)
| | - Yiing Lin
- Department of Surgery, Washington University in St. Louis, St. Louis, MO 63110, USA; (W.C.C.); (Y.L.)
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6
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Soldatov VO, Kubekina MV, Skorkina MY, Belykh AE, Egorova TV, Korokin MV, Pokrovskiy MV, Deykin AV, Angelova PR. Current advances in gene therapy of mitochondrial diseases. J Transl Med 2022; 20:562. [PMID: 36471396 PMCID: PMC9724384 DOI: 10.1186/s12967-022-03685-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/04/2022] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial diseases (MD) are a heterogeneous group of multisystem disorders involving metabolic errors. MD are characterized by extremely heterogeneous symptoms, ranging from organ-specific to multisystem dysfunction with different clinical courses. Most primary MD are autosomal recessive but maternal inheritance (from mtDNA), autosomal dominant, and X-linked inheritance is also known. Mitochondria are unique energy-generating cellular organelles designed to survive and contain their own unique genetic coding material, a circular mtDNA fragment of approximately 16,000 base pairs. The mitochondrial genetic system incorporates closely interacting bi-genomic factors encoded by the nuclear and mitochondrial genomes. Understanding the dynamics of mitochondrial genetics supporting mitochondrial biogenesis is especially important for the development of strategies for the treatment of rare and difficult-to-diagnose diseases. Gene therapy is one of the methods for correcting mitochondrial disorders.
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Affiliation(s)
- Vladislav O Soldatov
- Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
- Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia.
- Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia.
| | - Marina V Kubekina
- Core Facility Centre, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Marina Yu Skorkina
- Department of Biochemistry, Belgorod State National Research University, Belgorod, Russia
- Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia
| | - Andrei E Belykh
- Dioscuri Centre for Metabolic Diseases, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Tatiana V Egorova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail V Korokin
- Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Mikhail V Pokrovskiy
- Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
| | - Alexey V Deykin
- Department of Pharmacology and Clinical Pharmacology, Belgorod State National Research University, Belgorod, Russia
- Laboratory of Genome Editing for Biomedicine and Animal Health, Belgorod State National Research University, Belgorod, Russia
| | - Plamena R Angelova
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
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7
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Fan X, Yan T, Hou T, Xiong X, Feng L, Li S, Wang Z. Mitochondrial changes in fish cells in vitro in response to serum deprivation. FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:869-881. [PMID: 35652993 DOI: 10.1007/s10695-022-01088-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Mitochondria are critical to cellular activity that implicated in expansive networks to maintain organismal homeostasis under external stimuli of nutrient variability, a common and severe stress to fish performance during the intensive culture conditions. In the present study, zebrafish embryonic fibroblast cells were used to investigate the fish mitochondrial changes upon serum deprivation. Results showed that mitochondrial content and membrane potential were significantly reduced with increased intracellular ROS level in the serum deprivation treated fish cells. And the impaired mitochondria were characterized by rough and fracted outer membrane, and more fused mitochondria were frequently observed with the upregulated mRNA expressions of mitochondrial fusion genes (mfn1b, mfn2, and opa1). Besides, the mitochondrial DNA (mtDNA) copy numbers of mtatp6, mtcox1, mtcytb, mtnd4, and mtnd6 were overall showing the highly significant reduction, together with the mRNA expressions of these genes significantly increased, exhibiting the compensatory effects in mitochondria. Furthermore, the methyl-cytosine of whole mtDNA was compared and the methyl-reads numbers were distinctly increased in the treatment group, reflecting the instability of fish mtDNA with mitochondrial dysfunction under nutrient fluctuations. Collectively, current findings could facilitate the integrated research between fish mitochondrial response and external variables that indicates the potentially profound and durative deficits in fish health during the aquaculture processes.
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Affiliation(s)
- Xiaoteng Fan
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Tao Yan
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Tingting Hou
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Xiaofan Xiong
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Leilei Feng
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Shiyi Li
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Zaizhao Wang
- College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
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Meshnik L, Bar-Yaacov D, Kasztan D, Neiger T, Cohen T, Kishner M, Valenci I, Dadon S, Klein CJ, Vance JM, Nevo Y, Züchner S, Ovadia O, Mishmar D, Ben-Zvi A. Mutant C. elegans mitofusin leads to selective removal of mtDNA heteroplasmic deletions across generations to maintain fitness. BMC Biol 2022; 20:40. [PMID: 35139855 PMCID: PMC8829988 DOI: 10.1186/s12915-022-01241-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/28/2022] [Indexed: 11/20/2022] Open
Abstract
Background Mitochondrial DNA (mtDNA) is present at high copy numbers in animal cells, and though characterized by a single haplotype in each individual due to maternal germline inheritance, deleterious mutations and intact mtDNA molecules frequently co-exist (heteroplasmy). A number of factors, such as replicative segregation, mitochondrial bottlenecks, and selection, may modulate the exitance of heteroplasmic mutations. Since such mutations may have pathological consequences, they likely survive and are inherited due to functional complementation via the intracellular mitochondrial network. Here, we hypothesized that compromised mitochondrial fusion would hamper such complementation, thereby affecting heteroplasmy inheritance. Results We assessed heteroplasmy levels in three Caenorhabditis elegans strains carrying different heteroplasmic mtDNA deletions (ΔmtDNA) in the background of mutant mitofusin (fzo-1). Animals displayed severe embryonic lethality and developmental delay. Strikingly, observed phenotypes were relieved during subsequent generations in association with complete loss of ΔmtDNA molecules. Moreover, deletion loss rates were negatively correlated with the size of mtDNA deletions, suggesting that mitochondrial fusion is essential and sensitive to the nature of the heteroplasmic mtDNA mutations. Introducing the ΔmtDNA into a fzo-1;pdr-1;+/ΔmtDNA (PARKIN ortholog) double mutant resulted in a skewed Mendelian progeny distribution, in contrast to the normal distribution in the fzo-1;+/ΔmtDNA mutant, and severely reduced brood size. Notably, the ΔmtDNA was lost across generations in association with improved phenotypes. Conclusions Taken together, our findings show that when mitochondrial fusion is compromised, deleterious heteroplasmic mutations cannot evade natural selection while inherited through generations. Moreover, our findings underline the importance of cross-talk between mitochondrial fusion and mitophagy in modulating the inheritance of mtDNA heteroplasmy. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01241-2.
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Affiliation(s)
- Lana Meshnik
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Dan Bar-Yaacov
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Dana Kasztan
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Tali Neiger
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Tal Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Mor Kishner
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Itay Valenci
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Sara Dadon
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Christopher J Klein
- Department of Neurology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Jeffery M Vance
- Dr. John T. Macdonald Foundation Department of Human Genetics and Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Yoram Nevo
- Institute of Neurology, Schneider Children's Medical Center of Israel, Tel-Aviv University, Petach Tikva, Israel
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Ofer Ovadia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Anat Ben-Zvi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
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9
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The role of protein acetylation in regulating mitochondrial fusion and fission. Biochem Soc Trans 2021; 49:2807-2819. [PMID: 34812890 DOI: 10.1042/bst20210798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 12/12/2022]
Abstract
The dynamic processes of mitochondrial fusion and fission determine the shape of mitochondria, which can range from individual fragments to a hyperfused network, and influence mitochondrial function. Changes in mitochondrial shape can occur rapidly, allowing mitochondria to adapt to specific cues and changing cellular demands. Here, we will review what is known about how key proteins required for mitochondrial fusion and fission are regulated by their acetylation status, with acetylation promoting fission and deacetylation enhancing fusion. In particular, we will examine the roles of NAD+ dependant sirtuin deacetylases, which mediate mitochondrial acetylation, and how this post-translational modification provides an exquisite regulatory mechanism to co-ordinate mitochondrial function with metabolic demands of the cell.
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10
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Bagshaw OR, Moradi F, Moffatt CS, Hettwer HA, Liang P, Goldman J, Drelich JW, Stuart JA. Bioabsorbable metal zinc differentially affects mitochondria in vascular endothelial and smooth muscle cells. BIOMATERIALS AND BIOSYSTEMS 2021; 4:100027. [PMID: 36824572 PMCID: PMC9934485 DOI: 10.1016/j.bbiosy.2021.100027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/09/2021] [Accepted: 08/25/2021] [Indexed: 12/13/2022] Open
Abstract
Zinc is an essential trace element having various structural, catalytic and regulatory interactions with an estimated 3000 proteins. Zinc has drawn recent attention for its use, both as pure metal and alloyed, in arterial stents due to its biodegradability, biocompatibility, and low corrosion rates. Previous studies have demonstrated that zinc metal implants prevent the development of neointimal hyperplasia, which is a common cause of restenosis following coronary intervention. This suppression appears to be smooth muscle cell-specific, as reendothelization of the neointima is not inhibited. To better understand the basis of zinc's differential effects on rat aortic smooth muscle (RASMC) versus endothelial (RAENDO) cells, we conducted a transcriptomic analysis of both cell types following one-week continuous treatment with 5 µM or 50 µM zinc. This analysis indicated that genes whose protein products regulate mitochondrial functions, including oxidative phosphorylation and fusion/fission, are differentially affected by zinc in the two cell types. To better understand this, we performed Seahorse metabolic flux assays and quantitative imaging of mitochondrial networks in both cell types. Zinc treatment differently affected energy metabolism and mitochondrial structure/function in the two cell types. For example, both basal and maximal oxygen consumption rates were increased by zinc in RASMC but not in RAENDO. Zinc treatment increased apparent mitochondrial fusion in RASMC cells but increased mitochondrial fission in RAENDO cells. These results provide some insight into the mechanisms by which zinc treatment differently affects the two cell types and this information is important for understanding the role of zinc treatment in vascular cells and improving its use in biodegradable metal implants.
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Affiliation(s)
- Olivia R.M. Bagshaw
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S3A1, Canada
| | - Fereshteh Moradi
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S3A1, Canada
| | - Christopher S. Moffatt
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S3A1, Canada
| | - Hillary A. Hettwer
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S3A1, Canada
| | - Ping Liang
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S3A1, Canada
| | - Jeremy Goldman
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, United States
| | - Jaroslaw W. Drelich
- Department of Materials Science and Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, United States
| | - Jeffrey A. Stuart
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S3A1, Canada
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11
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Adlimoghaddam A, Odero GG, Glazner G, Turner RS, Albensi BC. Nilotinib Improves Bioenergetic Profiling in Brain Astroglia in the 3xTg Mouse Model of Alzheimer's Disease. Aging Dis 2021; 12:441-465. [PMID: 33815876 PMCID: PMC7990369 DOI: 10.14336/ad.2020.0910] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/10/2020] [Indexed: 12/27/2022] Open
Abstract
Current treatments targeting amyloid beta in Alzheimer's disease (AD) have minimal efficacy, which results in a huge unmet medical need worldwide. Accumulating data suggest that brain mitochondrial dysfunction play a critical role in AD pathogenesis. Targeting cellular mechanisms associated with mitochondrial dysfunction in AD create a novel approach for drug development. This study investigated the effects of nilotinib, as a selective tyrosine kinase inhibitor, in astroglia derived from 3xTg-AD mice versus their C57BL/6-controls. Parameters included oxygen consumption rates (OCR), ATP, cytochrome c oxidase (COX), citrate synthase (CS) activity, alterations in oxidative phosphorylation (OXPHOS), nuclear factor kappa B (NF-κB), key regulators of mitochondrial dynamics (mitofusin (Mfn1), dynamin-related protein 1 (Drp1)), and mitochondrial biogenesis (peroxisome proliferator-activated receptor gamma coactivator1-alpha (PGC-1α), calcium/calmodulin-dependent protein kinase II (CaMKII), and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)). Nilotinib increased OCR, ATP, COX, Mfn1, and OXPHOS levels in 3xTg astroglia. No significant differences were detected in levels of Drp1 protein and CS activity. Nilotinib enhanced mitochondrial numbers, potentially through a CaMKII-PGC1α-Nrf2 pathway in 3xTg astroglia. Additionally, nilotinib-induced OCR increases were reduced in the presence of the NF-κB inhibitor, Bay11-7082. The data suggest that NF-κB signaling is intimately involved in nilotinib-induced changes in bioenergetics in 3xTg brain astroglia. Nilotinib increased translocation of the NF-κB p50 subunit into the nucleus of 3xTg astroglia that correlates with an increased expression and activation of NF-κB. The current findings support a role for nilotinib in improving mitochondrial function and suggest that astroglia may be a key therapeutic target in treating AD.
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Affiliation(s)
- Aida Adlimoghaddam
- 1Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, MB, Canada
| | - Gary G Odero
- 1Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, MB, Canada
| | - Gordon Glazner
- 1Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, MB, Canada.,2Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - R Scott Turner
- 3Department of Neurology, Georgetown University, Washington, DC, USA
| | - Benedict C Albensi
- 1Division of Neurodegenerative Disorders, St. Boniface Hospital Research, Winnipeg, MB, Canada.,2Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB, Canada
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12
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Zeng M, He Y, Du H, Yang J, Wan H. Output Regulation and Function Optimization of Mitochondria in Eukaryotes. Front Cell Dev Biol 2020; 8:598112. [PMID: 33330486 PMCID: PMC7718039 DOI: 10.3389/fcell.2020.598112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 10/26/2020] [Indexed: 12/23/2022] Open
Abstract
The emergence of endosymbiosis between aerobic alpha-proteobacterium and anaerobic eukaryotic cell precursors opened the chapter of eukaryotic evolution. Multiple functions of mitochondria originated from the ancient precursors of mitochondria and underwent remodeling in eukaryotic cells. Due to the dependence on mitochondrial functions, eukaryotic cells need to constantly adjust mitochondrial output based on energy demand and cellular stress. Meanwhile, eukaryotes conduct the metabolic cooperation between different cells through the involvement of mitochondria. Under some conditions, mitochondria might also be transferred to nearby cells to provide a protective mechanism. However, the endosymbiont relationship determines the existence of various types of mitochondrial injury, such as proteotoxic stress, mutational meltdown, oxidative injure, and immune activation caused by released mitochondrial contents. Eukaryotes have a repertoire of mitochondrial optimization processes, including various mitochondrial quality-control proteins, regulation of mitochondrial dynamics and activation of mitochondrial autophagy. When these quality-control processes fail, eukaryotic cells can activate apoptosis to intercept uncontrolled cell death, thereby minimizing the damage to extracellular tissue. In this review, we describe the intracellular and extracellular context-based regulation of mitochondrial output in eukaryotic cells, and introduce new findings on multifaceted quality-control processes to deal with mitochondrial defects.
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Affiliation(s)
- Miaolin Zeng
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yu He
- College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Haixia Du
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jiehong Yang
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Haitong Wan
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China.,College of Life Science, Zhejiang Chinese Medical University, Hangzhou, China
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13
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Towarnicki SG, Ballard JWO. Towards understanding the evolutionary dynamics of mtDNA. Mitochondrial DNA A DNA Mapp Seq Anal 2020; 31:355-364. [PMID: 33026269 DOI: 10.1080/24701394.2020.1830076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Historically, mtDNA was considered a selectively neutral marker that was useful for estimating the population genetic history of the maternal lineage. Over time there has been an increasing appreciation of mtDNA and mitochondria in maintaining cellular and organismal health. Beyond energy production, mtDNA and mitochondria have critical cellular roles in signalling. Here we briefly review the structure of mtDNA and the role of the mitochondrion in energy production. We then discuss the predictions that can be obtained from quaternary structure modelling and focus on mitochondrial complex I. Complex I is the primary entry point for electrons into the electron transport system is the largest respiratory complex of the chain and produces about 40% of the proton flux used to synthesize ATP. A focus of the review is Drosophila's utility as a model organism to study the selective advantage of specific mutations. However, we note that the incorporation of insights from a multitude of systems is necessary to fully understand the range of roles that mtDNA has in organismal fitness. We speculate that dietary changes can illicit stress responses that influence the selective advantage of specific mtDNA mutations and cause spatial and temporal fluctuations in the frequencies of mutations. We conclude that developing our understanding of the roles mtDNA has in determining organismal fitness will enable increased evolutionary insight and propose we can no longer assume it is evolving as a strictly neutral marker without testing this hypothesis.
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Affiliation(s)
- Samuel G Towarnicki
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - J William O Ballard
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
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14
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Lujan SA, Longley MJ, Humble MH, Lavender CA, Burkholder A, Blakely EL, Alston CL, Gorman GS, Turnbull DM, McFarland R, Taylor RW, Kunkel TA, Copeland WC. Ultrasensitive deletion detection links mitochondrial DNA replication, disease, and aging. Genome Biol 2020; 21:248. [PMID: 32943091 PMCID: PMC7500033 DOI: 10.1186/s13059-020-02138-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 08/07/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Acquired human mitochondrial genome (mtDNA) deletions are symptoms and drivers of focal mitochondrial respiratory deficiency, a pathological hallmark of aging and late-onset mitochondrial disease. RESULTS To decipher connections between these processes, we create LostArc, an ultrasensitive method for quantifying deletions in circular mtDNA molecules. LostArc reveals 35 million deletions (~ 470,000 unique spans) in skeletal muscle from 22 individuals with and 19 individuals without pathogenic variants in POLG. This nuclear gene encodes the catalytic subunit of replicative mitochondrial DNA polymerase γ. Ablation, the deleted mtDNA fraction, suffices to explain skeletal muscle phenotypes of aging and POLG-derived disease. Unsupervised bioinformatic analyses reveal distinct age- and disease-correlated deletion patterns. CONCLUSIONS These patterns implicate replication by DNA polymerase γ as the deletion driver and suggest little purifying selection against mtDNA deletions by mitophagy in postmitotic muscle fibers. Observed deletion patterns are best modeled as mtDNA deletions initiated by replication fork stalling during strand displacement mtDNA synthesis.
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Affiliation(s)
- Scott A Lujan
- Genome Integrity and Structural Biology Laboratory, DNA Replication Fidelity Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Matthew J Longley
- Genome Integrity and Structural Biology Laboratory, Mitochondrial DNA Replication Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Margaret H Humble
- Genome Integrity and Structural Biology Laboratory, Mitochondrial DNA Replication Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Christopher A Lavender
- Integrative Bioinformatics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Adam Burkholder
- Integrative Bioinformatics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Emma L Blakely
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE1 4LP, UK
| | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE1 4LP, UK
| | - Grainne S Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Mitochondrial Diagnostic Laboratory, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE1 4LP, UK
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, DNA Replication Fidelity Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - William C Copeland
- Genome Integrity and Structural Biology Laboratory, Mitochondrial DNA Replication Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
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15
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Quinn KM, Hussain T, Kraus F, Formosa LE, Lam WK, Dagley MJ, Saunders EC, Assmus LM, Wynne-Jones E, Loh L, van de Sandt CE, Cooper L, Good-Jacobson KL, Kedzierska K, Mackay LK, McConville MJ, Ramm G, Ryan MT, La Gruta NL. Metabolic characteristics of CD8 + T cell subsets in young and aged individuals are not predictive of functionality. Nat Commun 2020; 11:2857. [PMID: 32504069 PMCID: PMC7275080 DOI: 10.1038/s41467-020-16633-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 05/01/2020] [Indexed: 01/23/2023] Open
Abstract
Virtual memory T (TVM) cells are antigen-naïve CD8+ T cells that exist in a semi-differentiated state and exhibit marked proliferative dysfunction in advanced age. High spare respiratory capacity (SRC) has been proposed as a defining metabolic characteristic of antigen-experienced memory T (TMEM) cells, facilitating rapid functionality and survival. Given the semi-differentiated state of TVM cells and their altered functionality with age, here we investigate TVM cell metabolism and its association with longevity and functionality. Elevated SRC is a feature of TVM, but not TMEM, cells and it increases with age in both subsets. The elevated SRC observed in aged mouse TVM cells and human CD8+ T cells from older individuals is associated with a heightened sensitivity to IL-15. We conclude that elevated SRC is a feature of TVM, but not TMEM, cells, is driven by physiological levels of IL-15, and is not indicative of enhanced functionality in CD8+ T cells. Fatty acid oxidation (FAO) is thought to contribute to high spare respiratory capacity (SRC), which in turn affects CD8+ T cell function. Here, the authors show that ex vivo virtual memory T cells (and not antigen experienced memory T cells) have high SRC, a metabolic state that it is affected by ageing and IL-15 signalling and not directly by FAO.
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Affiliation(s)
- Kylie M Quinn
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia. .,School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia.
| | - Tabinda Hussain
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Felix Kraus
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Luke E Formosa
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Wai K Lam
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Michael J Dagley
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Eleanor C Saunders
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Lisa M Assmus
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.,Institute of Experimental Immunology, University Hospital Bonn, 53127, Bonn, Germany
| | - Erica Wynne-Jones
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC, Australia
| | - Liyen Loh
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC, Australia
| | - Carolien E van de Sandt
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC, Australia.,Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1066CX, Amsterdam, Netherlands
| | - Lucy Cooper
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Kim L Good-Jacobson
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Katherine Kedzierska
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC, Australia
| | - Laura K Mackay
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Parkville, VIC, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Georg Ramm
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, 3010, Australia.,Monash Ramaciotti Centre for Cryo-EM, Monash University, Clayton, VIC, Australia
| | - Michael T Ryan
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Nicole L La Gruta
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
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16
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Dorn GW. Mitofusins as mitochondrial anchors and tethers. J Mol Cell Cardiol 2020; 142:146-153. [PMID: 32304672 DOI: 10.1016/j.yjmcc.2020.04.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/24/2020] [Accepted: 04/11/2020] [Indexed: 12/18/2022]
Abstract
Mitochondria have their own genomes and their own agendas. Like their primitive bacterial ancestors, mitochondria interact with their environment and organelle colleagues at their physical interfaces, the outer mitochondrial membrane. Among outer membrane proteins, mitofusins (MFN) are increasingly recognized for their roles as arbiters of mitochondria-mitochondria and mitochondria-reticular interactions. This review examines the roles of MFN1 and MFN2 in the heart and other organs as proteins that tether mitochondria to each other or to other organelles, and as mitochondrial anchoring proteins for various macromolecular complexes. The consequences of MFN-mediated tethering and anchoring on mitochondrial fusion, motility, mitophagy, and mitochondria-ER calcium cross-talk are reviewed. Pathophysiological implications are explored from the perspective of mitofusin common functioning as tethering and anchoring proteins, rather than as mediators of individual processes. Finally, some informed speculation is provided for why mouse MFN knockout studies show severe multi-system phenotypes whereas rare human diseases linked to MFN mutations are limited in scope.
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Affiliation(s)
- Gerald W Dorn
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA.
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17
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Matkarimov BT, Saparbaev MK. DNA Repair and Mutagenesis in Vertebrate Mitochondria: Evidence for Asymmetric DNA Strand Inheritance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1241:77-100. [DOI: 10.1007/978-3-030-41283-8_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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18
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Shtolz N, Mishmar D. The Mitochondrial Genome–on Selective Constraints and Signatures at the Organism, Cell, and Single Mitochondrion Levels. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00342] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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19
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Zhao Y, Sun X, Hu D, Prosdocimo DA, Hoppel C, Jain MK, Ramachandran R, Qi X. ATAD3A oligomerization causes neurodegeneration by coupling mitochondrial fragmentation and bioenergetics defects. Nat Commun 2019; 10:1371. [PMID: 30914652 PMCID: PMC6435701 DOI: 10.1038/s41467-019-09291-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/01/2019] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial fragmentation and bioenergetic failure manifest in Huntington’s disease (HD), a fatal neurodegenerative disease. The factors that couple mitochondrial fusion/fission with bioenergetics and their impacts on neurodegeneration however remain poorly understood. Our proteomic analysis identifies mitochondrial protein ATAD3A as an interactor of mitochondrial fission GTPase, Drp1, in HD. Here we show that, in HD, ATAD3A dimerization due to deacetylation at K135 residue is required for Drp1-mediated mitochondrial fragmentation. Disturbance of ATAD3A steady state impairs mtDNA maintenance by disrupting TFAM/mtDNA binding. Blocking Drp1/ATAD3A interaction with a peptide, DA1, abolishes ATAD3A oligomerization, suppresses mitochondrial fragmentation and mtDNA lesion, and reduces bioenergetic deficits and cell death in HD mouse- and patient-derived cells. DA1 treatment reduces behavioral and neuropathological phenotypes in HD transgenic mice. Our findings demonstrate that ATAD3A plays a key role in neurodegeneration by linking Drp1-induced mitochondrial fragmentation to defective mtDNA maintenance, suggesting that DA1 might be useful for developing HD therapeutics. Huntington’s disease leads to mitochondrial fragmentation and bioenergetic failure, although how the two events are connected is poorly understood. Here, Zhao et al. identify ATAD3A as a molecular linker and show that a peptide inhibitor of ATAD3A oligomerization suppresses HD phenotypes.
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Affiliation(s)
- Yuanyuan Zhao
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Xiaoyan Sun
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Di Hu
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Domenick A Prosdocimo
- Case Cardiovascular Research Institute and Harrington Heart and Vascular Institute, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Department of Medicine, University Hospitals Case Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Charles Hoppel
- Center for Mitochondrial Disease, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Mukesh K Jain
- Case Cardiovascular Research Institute and Harrington Heart and Vascular Institute, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Department of Medicine, University Hospitals Case Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Rajesh Ramachandran
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Xin Qi
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA. .,Center for Mitochondrial Disease, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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20
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Gustafsson ÅB, Dorn GW. Evolving and Expanding the Roles of Mitophagy as a Homeostatic and Pathogenic Process. Physiol Rev 2019; 99:853-892. [PMID: 30540226 PMCID: PMC6442924 DOI: 10.1152/physrev.00005.2018] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 08/10/2018] [Accepted: 09/29/2018] [Indexed: 02/07/2023] Open
Abstract
The central functions fulfilled by mitochondria as both energy generators essential for tissue homeostasis and gateways to programmed apoptotic and necrotic cell death mandate tight control over the quality and quantity of these ubiquitous endosymbiotic organelles. Mitophagy, the targeted engulfment and destruction of mitochondria by the cellular autophagy apparatus, has conventionally been considered as the mechanism primarily responsible for mitochondrial quality control. However, our understanding of how, why, and under what specific conditions mitophagy is activated has grown tremendously over the past decade. Evidence is accumulating that nonmitophagic mitochondrial quality control mechanisms are more important to maintaining normal tissue homeostasis whereas mitophagy is an acute tissue stress response. Moreover, previously unrecognized mitophagic regulation of mitochondrial quantity control, metabolic reprogramming, and cell differentiation suggests that the mechanisms linking genetic or acquired defects in mitophagy to neurodegenerative and cardiovascular diseases or cancer are more complex than simple failure of normal mitochondrial quality control. Here, we provide a comprehensive overview of mitophagy in cellular homeostasis and disease and examine the most revolutionary concepts in these areas. In this context, we discuss evidence that atypical mitophagy and nonmitophagic pathways play central roles in mitochondrial quality control, functioning that was previously considered to be the primary domain of mitophagy.
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Affiliation(s)
- Åsa B Gustafsson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego , La Jolla, California ; and Washington University School of Medicine, St. Louis, Missouri
| | - Gerald W Dorn
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego , La Jolla, California ; and Washington University School of Medicine, St. Louis, Missouri
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21
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Morris J, Na YJ, Zhu H, Lee JH, Giang H, Ulyanova AV, Baltuch GH, Brem S, Chen HI, Kung DK, Lucas TH, O'Rourke DM, Wolf JA, Grady MS, Sul JY, Kim J, Eberwine J. Pervasive within-Mitochondrion Single-Nucleotide Variant Heteroplasmy as Revealed by Single-Mitochondrion Sequencing. Cell Rep 2018; 21:2706-2713. [PMID: 29212019 DOI: 10.1016/j.celrep.2017.11.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/05/2017] [Accepted: 11/08/2017] [Indexed: 11/18/2022] Open
Abstract
A number of mitochondrial diseases arise from single-nucleotide variant (SNV) accumulation in multiple mitochondria. Here, we present a method for identification of variants present at the single-mitochondrion level in individual mouse and human neuronal cells, allowing for extremely high-resolution study of mitochondrial mutation dynamics. We identified extensive heteroplasmy between individual mitochondrion, along with three high-confidence variants in mouse and one in human that were present in multiple mitochondria across cells. The pattern of variation revealed by single-mitochondrion data shows surprisingly pervasive levels of heteroplasmy in inbred mice. Distribution of SNV loci suggests inheritance of variants across generations, resulting in Poisson jackpot lines with large SNV load. Comparison of human and mouse variants suggests that the two species might employ distinct modes of somatic segregation. Single-mitochondrion resolution revealed mitochondria mutational dynamics that we hypothesize to affect risk probabilities for mutations reaching disease thresholds.
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Affiliation(s)
- Jacqueline Morris
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Young-Ji Na
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hua Zhu
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jae-Hee Lee
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hoa Giang
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexandra V Ulyanova
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gordon H Baltuch
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Steven Brem
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - H Isaac Chen
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David K Kung
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Timothy H Lucas
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Donald M O'Rourke
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John A Wolf
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - M Sean Grady
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jai-Yoon Sul
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Junhyong Kim
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Eberwine
- Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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22
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Lia D, Reyes A, de Melo Campos JTA, Piolot T, Baijer J, Radicella JP, Campalans A. Mitochondrial maintenance under oxidative stress depends on mitochondrially localised α-OGG1. J Cell Sci 2018; 131:jcs.213538. [PMID: 29848661 DOI: 10.1242/jcs.213538] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/21/2018] [Indexed: 12/18/2022] Open
Abstract
Accumulation of 8-oxoguanine (8-oxoG) in mitochondrial DNA and mitochondrial dysfunction have been observed in cells deficient for the DNA glycosylase OGG1 when exposed to oxidative stress. In human cells, up to eight mRNAs for OGG1 can be generated by alternative splicing and it is still unclear which of them codes for the protein that ensures the repair of 8-oxoG in mitochondria. Here, we show that the α-OGG1 isoform, considered up to now to be exclusively nuclear, has a functional mitochondrial-targeting sequence and is imported into mitochondria. We analyse the sub-mitochondrial localisation of α-OGG1 with unprecedented resolution and show that this DNA glycosylase is associated with DNA in mitochondrial nucleoids. We show that the presence of α-OGG1 inside mitochondria and its enzymatic activity are required to preserve the mitochondrial network in cells exposed to oxidative stress. Altogether, these results unveil a new role of α-OGG1 in the mitochondria and indicate that the same isoform ensures the repair of 8-oxoG in both nuclear and mitochondrial genomes. The activity of α-OGG1 in mitochondria is sufficient for the recovery of organelle function after oxidative stress.
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Affiliation(s)
- Debora Lia
- Institut de Biologie François Jacob (IBFJ), Institute of Cellular and Molecular Radiobiology, CEA, UMR967 INSERM, 96265 Fontenay aux Roses, France.,Université Paris Diderot/Université Paris-Sud, 96265 Fontenay aux Roses, France
| | - Aurelio Reyes
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Julliane Tamara Araújo de Melo Campos
- Institut de Biologie François Jacob (IBFJ), Institute of Cellular and Molecular Radiobiology, CEA, UMR967 INSERM, 96265 Fontenay aux Roses, France.,Laboratório de Biologia Molecular e Genômica, Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN 59072-970, Brazil
| | - Tristan Piolot
- Institut Curie, CNRS UMR3215, INSERM U934, 75248 Paris, France
| | - Jan Baijer
- Institut de Biologie François Jacob (IBFJ), Institute of Cellular and Molecular Radiobiology, CEA, UMR967 INSERM, 96265 Fontenay aux Roses, France.,Université Paris Diderot/Université Paris-Sud, 96265 Fontenay aux Roses, France
| | - J Pablo Radicella
- Institut de Biologie François Jacob (IBFJ), Institute of Cellular and Molecular Radiobiology, CEA, UMR967 INSERM, 96265 Fontenay aux Roses, France.,Université Paris Diderot/Université Paris-Sud, 96265 Fontenay aux Roses, France
| | - Anna Campalans
- Institut de Biologie François Jacob (IBFJ), Institute of Cellular and Molecular Radiobiology, CEA, UMR967 INSERM, 96265 Fontenay aux Roses, France .,Université Paris Diderot/Université Paris-Sud, 96265 Fontenay aux Roses, France
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23
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Verechshagina NA, Konstantinov YM, Kamenski PA, Mazunin IO. Import of Proteins and Nucleic Acids into Mitochondria. BIOCHEMISTRY (MOSCOW) 2018; 83:643-661. [DOI: 10.1134/s0006297918060032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Delic V, Kurien C, Cruz J, Zivkovic S, Barretta J, Thomson A, Hennessey D, Joseph J, Ehrhart J, Willing AE, Bradshaw P, Garbuzova-Davis S. Discrete mitochondrial aberrations in the spinal cord of sporadic ALS patients. J Neurosci Res 2018; 96:1353-1366. [PMID: 29732581 DOI: 10.1002/jnr.24249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult onset neurodegenerative disease characterized by progressive motor neuron degeneration in the brain and spinal cord leading to muscle atrophy, paralysis, and death. Mitochondrial dysfunction is a major contributor to motor neuron degeneration associated with ALS progression. Mitochondrial abnormalities have been determined in spinal cords of animal disease models and ALS patients. However, molecular mechanisms leading to mitochondrial dysfunction in sporadic ALS (sALS) patients remain unclear. Also, segmental or regional variation in mitochondrial activity in the spinal cord has not been extensively examined in ALS. In our study, the activity of mitochondrial electron transport chain complex IV was examined in post-mortem gray and white matter of the cervical and lumbar spinal cords from male and female sALS patients and controls. Mitochondrial distribution and density in spinal cord motor neurons, lateral funiculus, and capillaries in gray and white matter were analyzed by immunohistochemistry. Results showed that complex IV activity was significantly decreased only in gray matter in both cervical and lumbar spinal cords from ALS patients. In ALS cervical and lumbar spinal cords, significantly increased mitochondrial density and altered distribution were observed in motor neurons, lateral funiculus, and cervical white matter capillaries. Discrete decreased complex IV activity in addition to changes in mitochondria distribution and density determined in the spinal cord in sALS patients are novel findings. These explicit mitochondrial defects in the spinal cord may contribute to ALS pathogenesis and should be considered in development of therapeutic approaches for this disease.
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Affiliation(s)
- Vedad Delic
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Crupa Kurien
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA
| | - Josean Cruz
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Sandra Zivkovic
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Jennifer Barretta
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA
| | - Avery Thomson
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA
| | - Daniel Hennessey
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA
| | - Jaheem Joseph
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA
| | - Jared Ehrhart
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA
| | - Alison E Willing
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA.,Department of Neurosurgery and Brain Repair, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
| | - Patrick Bradshaw
- Department of Biomedical Sciences, East Tennessee State University College of Medicine, Johnson City, Tennessee, USA
| | - Svitlana Garbuzova-Davis
- Morsani College of Medicine, Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, Florida, USA.,Department of Neurosurgery and Brain Repair, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA.,Department of Pathology and Cell Biology, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
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25
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Meyer JN, Leuthner TC, Luz AL. Mitochondrial fusion, fission, and mitochondrial toxicity. Toxicology 2017; 391:42-53. [PMID: 28789970 PMCID: PMC5681418 DOI: 10.1016/j.tox.2017.07.019] [Citation(s) in RCA: 329] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 07/10/2017] [Accepted: 07/31/2017] [Indexed: 12/17/2022]
Abstract
Mitochondrial dynamics are regulated by two sets of opposed processes: mitochondrial fusion and fission, and mitochondrial biogenesis and degradation (including mitophagy), as well as processes such as intracellular transport. These processes maintain mitochondrial homeostasis, regulate mitochondrial form, volume and function, and are increasingly understood to be critical components of the cellular stress response. Mitochondrial dynamics vary based on developmental stage and age, cell type, environmental factors, and genetic background. Indeed, many mitochondrial homeostasis genes are human disease genes. Emerging evidence indicates that deficiencies in these genes often sensitize to environmental exposures, yet can also be protective under certain circumstances. Inhibition of mitochondrial dynamics also affects elimination of irreparable mitochondrial DNA (mtDNA) damage and transmission of mtDNA mutations. We briefly review the basic biology of mitodynamic processes with a focus on mitochondrial fusion and fission, discuss what is known and unknown regarding how these processes respond to chemical and other stressors, and review the literature on interactions between mitochondrial toxicity and genetic variation in mitochondrial fusion and fission genes. Finally, we suggest areas for future research, including elucidating the full range of mitodynamic responses from low to high-level exposures, and from acute to chronic exposures; detailed examination of the physiological consequences of mitodynamic alterations in different cell types; mechanism-based testing of mitotoxicant interactions with interindividual variability in mitodynamics processes; and incorporating other environmental variables that affect mitochondria, such as diet and exercise.
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Affiliation(s)
- Joel N Meyer
- Nicholas School of the Environment and Integrated Toxicology and Environmental Health Program, Duke University, Durham, NC 27708-0328, United States.
| | - Tess C Leuthner
- Nicholas School of the Environment and Integrated Toxicology and Environmental Health Program, Duke University, Durham, NC 27708-0328, United States.
| | - Anthony L Luz
- Nicholas School of the Environment and Integrated Toxicology and Environmental Health Program, Duke University, Durham, NC 27708-0328, United States.
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26
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Luz AL, Godebo TR, Smith LL, Leuthner TC, Maurer LL, Meyer JN. Deficiencies in mitochondrial dynamics sensitize Caenorhabditis elegans to arsenite and other mitochondrial toxicants by reducing mitochondrial adaptability. Toxicology 2017; 387:81-94. [PMID: 28602540 PMCID: PMC5535741 DOI: 10.1016/j.tox.2017.05.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 05/10/2017] [Accepted: 05/30/2017] [Indexed: 01/06/2023]
Abstract
Mitochondrial fission, fusion, and mitophagy are interlinked processes that regulate mitochondrial shape, number, and size, as well as metabolic activity and stress response. The fundamental importance of these processes is evident in the fact that mutations in fission (DRP1), fusion (MFN2, OPA1), and mitophagy (PINK1, PARK2) genes can cause human disease (collectively >1/10,000). Interestingly, however, the age of onset and severity of clinical manifestations varies greatly between patients with these diseases (even those harboring identical mutations), suggesting a role for environmental factors in the development and progression of certain mitochondrial diseases. Using the model organism Caenorhabditis elegans, we screened ten mitochondrial toxicants (2, 4-dinitrophenol, acetaldehyde, acrolein, aflatoxin B1, arsenite, cadmium, cisplatin, doxycycline, paraquat, rotenone) for increased or decreased toxicity in fusion (fzo-1, eat-3)-, fission (drp-1)-, and mitophagy (pdr-1, pink-1)-deficient nematodes using a larval growth assay. In general, fusion-deficient nematodes were the most sensitive to toxicants, including aflatoxin B1, arsenite, cisplatin, paraquat, and rotenone. Because arsenite was particularly potent in fission- and fusion-deficient nematodes, and hundreds of millions of people are chronically exposed to arsenic, we investigated the effects of these genetic deficiencies on arsenic toxicity in more depth. We found that deficiencies in fission and fusion sensitized nematodes to arsenite-induced lethality throughout aging. Furthermore, low-dose arsenite, which acted in a "mitohormetic" fashion by increasing mitochondrial function (in particular, basal and maximal oxygen consumption) in wild-type nematodes by a wide range of measures, exacerbated mitochondrial dysfunction in fusion-deficient nematodes. Analysis of multiple mechanistic changes suggested that disruption of pyruvate metabolism and Krebs cycle activity underlie the observed arsenite-induced mitochondrial deficits, and these disruptions are exacerbated in the absence of mitochondrial fusion. This research demonstrates the importance of mitochondrial dynamics in limiting arsenite toxicity by permitting mitochondrial adaptability. It also suggests that individuals suffering from deficiencies in mitodynamic processes may be more susceptible to the mitochondrial toxicity of arsenic and other toxicants.
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Affiliation(s)
- Anthony L Luz
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Tewodros R Godebo
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Latasha L Smith
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Tess C Leuthner
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Laura L Maurer
- ExxonMobil Biomedical Sciences, Inc., Annandale, NJ, 08801-3059, USA
| | - Joel N Meyer
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA.
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27
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Mitochondrial Nucleoid: Shield and Switch of the Mitochondrial Genome. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:8060949. [PMID: 28680532 PMCID: PMC5478868 DOI: 10.1155/2017/8060949] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/06/2017] [Accepted: 04/03/2017] [Indexed: 11/18/2022]
Abstract
Mitochondria preserve very complex and distinctively unique machinery to maintain and express the content of mitochondrial DNA (mtDNA). Similar to chromosomes, mtDNA is packaged into discrete mtDNA-protein complexes referred to as a nucleoid. In addition to its role as a mtDNA shield, over 50 nucleoid-associated proteins play roles in mtDNA maintenance and gene expression through either temporary or permanent association with mtDNA or other nucleoid-associated proteins. The number of mtDNA(s) contained within a single nucleoid is a fundamental question but remains a somewhat controversial issue. Disturbance in nucleoid components and mutations in mtDNA were identified as significant in various diseases, including carcinogenesis. Significant interest in the nucleoid structure and its regulation has been stimulated in relation to mitochondrial diseases, which encompass diseases in multicellular organisms and are associated with accumulation of numerous mutations in mtDNA. In this review, mitochondrial nucleoid structure, nucleoid-associated proteins, and their regulatory roles in mitochondrial metabolism are briefly addressed to provide an overview of the emerging research field involving mitochondrial biology.
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28
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Stefano GB, Kream RM. Mitochondrial DNA heteroplasmy in human health and disease. Biomed Rep 2016; 4:259-262. [PMID: 26998260 PMCID: PMC4774312 DOI: 10.3892/br.2016.590] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/02/2016] [Indexed: 12/14/2022] Open
Abstract
The biomedical literature has extensively documented the functional roles of genetic polymorphisms in concert with well-characterized somatic mutations in the etiology and progression of major metastatic diseases afflicting human populations. Mitochondrial heteroplasmy exists as a dynamically determined co-expression of inherited polymorphisms and somatic mutations in varying ratios within individual mitochondrial DNA genomes with repetitive patterns of tissue specificity. Mechanistically, carcinogenic cellular processes include profound alterations of normative mitochondrial function, notably dependence on aerobic and anaerobic glycolysis, and aberrant production and release of lactate, according to a classic theory. Within the translational context of human health and disease, the present review discusses the necessity of establishing critical foci designed to probe multiple biological roles of mitochondrial heteroplasmy in cancer biology.
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29
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Abstract
Mitochondria are highly dynamic, except in adult cardiomyocytes. Yet, the fission and fusion-promoting proteins that mediate mitochondrial dynamism are highly expressed in, and essential to the normal functioning of, hearts. Here, we review accumulating evidence supporting important roles for mitochondrial fission and fusion in cardiac mitochondrial quality control, focusing on the PTEN-induced putative kinase 1-Parkin mitophagy pathway. Based in part on recent findings from in vivo mouse models in which mitofusin-mediated mitochondrial fusion or dynamin-related protein 1-mediated mitochondrial fission was conditionally interrupted in cardiac myocytes, we propose several new concepts that may provide insight into the cardiac mitochondrial dynamism-mitophagy interactome.
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Affiliation(s)
- Orian S Shirihai
- From the Department of Medicine, Evans Center, Boston University School of Medicine, MA (O.S.S.); Department of Biochemistry, Ben Gurion University of the Negev, Beer Sheva, Israel (O.S.S.); and Center for Pharmacogenomics, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO (M.S., G.W.D.)
| | - Moshi Song
- From the Department of Medicine, Evans Center, Boston University School of Medicine, MA (O.S.S.); Department of Biochemistry, Ben Gurion University of the Negev, Beer Sheva, Israel (O.S.S.); and Center for Pharmacogenomics, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO (M.S., G.W.D.)
| | - Gerald W Dorn
- From the Department of Medicine, Evans Center, Boston University School of Medicine, MA (O.S.S.); Department of Biochemistry, Ben Gurion University of the Negev, Beer Sheva, Israel (O.S.S.); and Center for Pharmacogenomics, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO (M.S., G.W.D.).
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30
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Mitochondria in health, aging and diseases: the epigenetic perspective. Biogerontology 2015; 16:569-85. [DOI: 10.1007/s10522-015-9562-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 02/19/2015] [Indexed: 01/15/2023]
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31
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Pyrosequencing is an accurate and reliable method for the analysis of heteroplasmy of the A3243G mutation in patients with mitochondrial diabetes. J Mol Diagn 2014; 16:431-9. [PMID: 24803323 DOI: 10.1016/j.jmoldx.2014.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/01/2014] [Accepted: 03/14/2014] [Indexed: 01/12/2023] Open
Abstract
Human mitochondrial DNA is a circular DNA molecule that encodes some of the proteins required for oxidative phosphorylation. Different mitochondrial DNA genotypes may coexist within a single cell, a condition known as heteroplasmy. An A-to-G transition at position 3243 of mitochondrial DNA (A3243G) can result in maternally inherited diabetes and deafness (mitochondrial diabetes). However, the commonly used methods of PCR restriction fragment length polymorphism and Sanger sequencing are neither sensitive nor reliable enough to detect this low level of heteroplasmy. Here, we developed a quantitative method based on pyrosequencing to analyze the heteroplasmy of the A3243G mutation in leukocyte DNA obtained from 83 persons of 15 unrelated pedigrees with mitochondrial diabetes. The accuracy and reliability of this method were also measured by comparing the results with those from high-resolution melting analysis, Sanger sequencing, and PCR restriction fragment length polymorphism with artificial heteroplasmy standard samples. The results showed that the accuracy of pyrosequencing was much higher than that of the other methods, and the limitation of heteroplasmy detection with this method reached 2%, based on our artificial control studies. An inverse correlation was found between the level of heteroplasmy and the age of the onset in our patients. This result suggested that the heteroplasmy of the A3243G mutation could become a significant prediction index for the onset of mitochondrial diabetes.
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32
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St John J. The control of mtDNA replication during differentiation and development. Biochim Biophys Acta Gen Subj 2013; 1840:1345-54. [PMID: 24183916 DOI: 10.1016/j.bbagen.2013.10.036] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 10/22/2013] [Accepted: 10/23/2013] [Indexed: 12/01/2022]
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) is important for energy production as it encodes some of the key genes of electron transfer chain, where the majority of cellular energy is generated through oxidative phosphorylation (OXPHOS). MtDNA replication is mediated by nuclear DNA-encoded proteins or enzymes, which translocate to the mitochondria, and is strictly regulated throughout development. It starts with approximately 200 copies in each primordial germ cell and these copies undergo expansion and restriction events at various stages of development. SCOPE OF REVIEW I describe the patterns of mtDNA replication at key stages of development. I explain that it is essential to regulate mtDNA copy number and to establish the mtDNA set point in order that the mature, specialised cell acquires the appropriate numbers of mtDNA copy to generate sufficient adenosine triphosphate (ATP) through OXPHOS to undertake its specialised function. I discuss how these processes are dependent on the controlled expression of the nuclear-encoded mtDNA-specific replication factors and that this can be modulated by mtDNA haplotypes. I discuss how these events are altered by certain assisted reproductive technologies, some of which have been proposed to prevent the transmission of mutant mtDNA and others to overcome infertility. Furthermore, some of these technologies are predisposed to transmitting two or more populations of mtDNA, which can be extremely harmful. MAJOR CONCLUSIONS The failure to regulate mtDNA replication and mtDNA transmission during development is disadvantageous. GENERAL SIGNIFICANCE Manipulation of oocytes and embryos can lead to significant implications for the maternal-only transmission of mtDNA. This article is part of a Special Issue entitled Frontiers of mitochondrial research.
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Affiliation(s)
- Justin St John
- Mitochondrial Genetics Group, Centre for Genetic Diseases, Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
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33
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Figueira TR, Barros MH, Camargo AA, Castilho RF, Ferreira JCB, Kowaltowski AJ, Sluse FE, Souza-Pinto NC, Vercesi AE. Mitochondria as a source of reactive oxygen and nitrogen species: from molecular mechanisms to human health. Antioxid Redox Signal 2013; 18:2029-74. [PMID: 23244576 DOI: 10.1089/ars.2012.4729] [Citation(s) in RCA: 304] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mitochondrially generated reactive oxygen species are involved in a myriad of signaling and damaging pathways in different tissues. In addition, mitochondria are an important target of reactive oxygen and nitrogen species. Here, we discuss basic mechanisms of mitochondrial oxidant generation and removal and the main factors affecting mitochondrial redox balance. We also discuss the interaction between mitochondrial reactive oxygen and nitrogen species, and the involvement of these oxidants in mitochondrial diseases, cancer, neurological, and cardiovascular disorders.
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Affiliation(s)
- Tiago R Figueira
- Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil
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Abstract
Mitochondrial fission and fusion play critical roles in maintaining functional mitochondria when cells experience metabolic or environmental stresses. Fusion helps mitigate stress by mixing the contents of partially damaged mitochondria as a form of complementation. Fission is needed to create new mitochondria, but it also contributes to quality control by enabling the removal of damaged mitochondria and can facilitate apoptosis during high levels of cellular stress. Disruptions in these processes affect normal development, and they have been implicated in neurodegenerative diseases, such as Parkinson's.
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Affiliation(s)
- Richard J Youle
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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35
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Kang S, Louboutin JP, Datta P, Landel CP, Martinez D, Zervos AS, Strayer DS, Fernandes-Alnemri T, Alnemri ES. Loss of HtrA2/Omi activity in non-neuronal tissues of adult mice causes premature aging. Cell Death Differ 2012; 20:259-69. [PMID: 22976834 DOI: 10.1038/cdd.2012.117] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
mnd2 mice die prematurely as a result of neurodegeneration 30-40 days after birth due to loss of the enzymatic activity of the mitochondrial quality control protease HtrA2/Omi. Here, we show that transgenic expression of human HtrA2/Omi in the central nervous system of mnd2 mice rescues them from neurodegeneration and prevents their premature death. Interestingly, adult transgenic mnd2 mice develop accelerated aging phenotypes, such as premature weight loss, hair loss, reduced fertility, curvature of the spine, heart enlargement, increased autophagy, and death by 12-17 months of age. These mice also have elevated levels of clonally expanded mitochondrial DNA (mtDNA) deletions in their tissues. Our results provide direct genetic evidence linking mitochondrial protein quality control to mtDNA deletions and aging in mammals.
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Affiliation(s)
- S Kang
- Department of Biochemistry and Molecular Biology, The Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
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36
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Bradshaw E, Yoshida M, Ling F. Mitochondrial fission proteins Fis1 and Mdv1, but not Dnm1, play a role in maintenance of heteroplasmy in budding yeast. FEBS Lett 2012; 586:1245-51. [PMID: 22575664 DOI: 10.1016/j.febslet.2012.03.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/27/2012] [Accepted: 03/19/2012] [Indexed: 01/11/2023]
Abstract
In budding yeast, the mitochondrial DNA (mtDNA) replication pathway involving the homologous DNA pairing protein Mhr1 promotes mitochondrial allele segregation. Mitochondrial fusion facilitates the recombination-mediated replication pathway; however, the role of fission remains largely unknown. By monitoring mitochondrial allele segregation during zygotic division, we found that the absence of fission proteins Fis1 or Mdv1, but not Dnm1, resulted in increased initial homoplasmy levels and decreased mtDNA copy number. However, decreases in mtDNA copy number alone were not sufficient for rapid establishment of homoplasmy, suggesting that inhibiting the activities of certain fission proteins promotes homoplasmy by reducing the number of mtDNA segregation units.
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Affiliation(s)
- Elliot Bradshaw
- Chemical Genetics Laboratory, RIKEN Advanced Science Institute, Wako-shi, Saitama, Japan
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37
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Wallace DC. Bioenergetic origins of complexity and disease. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2011; 76:1-16. [PMID: 22194359 DOI: 10.1101/sqb.2011.76.010462] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The organizing power of energy flow is hypothesized to be the origin of biological complexity and its decline the basis of "complex" diseases and aging. Energy flow through organic systems creates nucleic acids, which store information, and the annual accumulation of information generates today's complexity. Energy flow through our bodies is mediated by the mitochondria, symbiotic bacteria whose genomes encompass the mitochondrial DNA (mtDNA) and more than 1000 nuclear genes. Inherited and/or epigenomic variation of the mitochondrial genome determines our initial energetic capacity, but the age-related accumulation of somatic cell mtDNA mutations further erodes energy flow, leading to disease. This bioenergetic perspective on disease provides a unifying pathophysiological and genetic mechanism for neuropsychiatric diseases such as Alzheimer and Parkinson Disease, metabolic diseases such as diabetes and obesity, autoimmune diseases, aging, and cancer.
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Affiliation(s)
- D C Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia Research Institute and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-4302, USA.
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Abstract
Mitochondrial dynamics and mitophagy are recognized as two critical processes underlying mitochondrial homeostasis. Morphological and bioenergetic characterization of the life cycle of an individual mitochondrion reveals several points where fusion, fission, and mitophagy interact. Mitochondrial fission can produce an impaired daughter unit that will be targeted by the autophagic machinery. Mitochondrial fusion, on the other hand, may serve to dilute impaired respiratory components and thereby prevent their removal. The inverse dependency of fusion and mitophagy on membrane potential allows them to act as complementary rather than competitive fates of the daughter mitochondrion after a fission event. We discuss the interplay between mitochondrial dynamics and mitophagy in different tissues and in different disease models under both stress-induced and steady-state conditions.
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Affiliation(s)
- Gilad Twig
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Clark J, Dai Y, Simon DK. Do somatic mitochondrial DNA mutations contribute to Parkinson's disease? PARKINSONS DISEASE 2011; 2011:659694. [PMID: 21603185 PMCID: PMC3096076 DOI: 10.4061/2011/659694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 03/01/2011] [Indexed: 12/21/2022]
Abstract
A great deal of evidence supports a role for mitochondrial dysfunction in the pathogenesis of Parkinson's disease (PD), although the origin of the mitochondrial dysfunction in PD remains unclear. Expression of mitochondrial DNA (mtDNA) from PD patients in “cybrid” cell lines recapitulates the mitochondrial defect, implicating a role for mtDNA mutations, but the specific mutations responsible for the mitochondrial dysfunction in PD have been difficult to identify. Somatic mtDNA point mutations and deletions accumulate with age and reach high levels in substantia nigra (SN) neurons. Mutations in mitochondrial DNA polymerase γ (POLG) that lead to the accumulation of mtDNA mutations are associated with a premature aging phenotype in “mutator” mice, although overt parkinsonism has not been reported in these mice, and with parkinsonism in humans. Together these data support, but do not yet prove, the hypothesis that the accumulation of somatic mtDNA mutations in SN neurons contribute to the pathogenesis of PD.
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Affiliation(s)
- Joanne Clark
- Department of Neurology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, E/CLS-628, Boston, MA 02215, USA
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Yoon YG, Koob MD. Toward genetic transformation of mitochondria in mammalian cells using a recoded drug-resistant selection marker. J Genet Genomics 2011; 38:173-9. [PMID: 21530901 DOI: 10.1016/j.jgg.2011.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 03/07/2011] [Accepted: 03/10/2011] [Indexed: 01/04/2023]
Abstract
Due to technical difficulties, the genetic transformation of mitochondria in mammalian cells is still a challenge. In this report, we described our attempts to transform mammalian mitochondria with an engineered mitochondrial genome based on selection using a drug resistance gene. Because the standard drug-resistant neomycin phosphotransferase confers resistance to high concentrations of G418 when targeted to the mitochondria, we generated a recoded neomycin resistance gene that uses the mammalian mitochondrial genetic code to direct the synthesis of this protein in the mitochondria, but not in the nucleus (mitochondrial version). We also generated a universal version of the recoded neomycin resistance gene that allows synthesis of the drug-resistant proteins both in the mitochondria and nucleus. When we transfected these recoded neomycin resistance genes that were incorporated into the mouse mitochondrial genome clones into mouse tissue culture cells by electroporation, no DNA constructs were delivered into the mitochondria. We found that the universal version of the recoded neomycin resistance gene was expressed in the nucleus and thus conferred drug resistance to G418 selection, while the synthetic mitochondrial version of the gene produced no background drug-resistant cells from nuclear transformation. These recoded synthetic drug-resistant genes could be a useful tool for selecting mitochondrial genetic transformants as a precise technology for mitochondrial transformation is developed.
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Affiliation(s)
- Young Geol Yoon
- Mitochondria Hub Regulation Center and Department of Anatomy and Cell Biology, Dong-A University College of Medicine, 3-1 Dongdaesin-dong, Seo-gu, Busan 602-714, Republic of Korea.
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Bibliography. Genetics. Current world literature. Curr Opin Pediatr 2010; 22:833-5. [PMID: 21610333 DOI: 10.1097/mop.0b013e32834179f9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Burchell VS, Gandhi S, Deas E, Wood NW, Abramov AY, Plun-Favreau H. Targeting mitochondrial dysfunction in neurodegenerative disease: Part II. Expert Opin Ther Targets 2010; 14:497-511. [PMID: 20334487 DOI: 10.1517/14728221003730434] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
IMPORTANCE OF THE FIELD With improvements in life expectancy over the past decades, the incidence of neurodegenerative disease has dramatically increased and new therapeutic strategies are urgently needed. One possible approach is to target mitochondrial dysfunction, which has been implicated in the pathogenesis of numerous neurodegenerative disorders. AREAS COVERED IN THIS REVIEW This review examines the role of mitochondrial dysfunction in neurodegeneration, drawing examples from common diseases such as Alzheimer's disease and rarer familial disorders such as Charcot-Marie-Tooth. The review is provided in two parts. In part I we discussed the mitochondrial defects which have been most extensively researched (oxidative stress, bioenergetic dysfunction, calcium mishandling). We focus now on those defects which have more recently been implicated in neurodegeneration; in mitochondrial fusion/fission, protein import, protein quality control, kinase signalling and opening of the permeability transition pore. WHAT THE READER WILL GAIN An examination of mitochondrial defects observed in neurodegeneration, and existing and possible future therapies to target these defects. TAKE HOME MESSAGE The mitochondrially-targeted therapeutics that have reached clinical trials so far have produced encouraging but largely inconclusive results. Increasing understanding of mitochondrial dysfunction has, however, led to preclinical work focusing on novel approaches, which has generated exciting preliminary data.
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Affiliation(s)
- Victoria S Burchell
- UCL Institute of Neurology, Department of Molecular Neuroscience, Queen Square, London WC1N 3BG, UK
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Detection of heteroplasmy in individual mitochondrial particles. Anal Bioanal Chem 2010; 397:3397-407. [PMID: 20467729 DOI: 10.1007/s00216-010-3751-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 04/12/2010] [Accepted: 04/13/2010] [Indexed: 10/19/2022]
Abstract
Mitochondrial DNA (mtDNA) mutations have been associated with disease and aging. Since each cell has thousands of mtDNA copies, clustered into nucleoids of five to ten mtDNA molecules each, determining the effects of a given mtDNA mutation and their connection with disease phenotype is not straightforward. It has been postulated that heteroplasmy (coexistence of mutated and wild-type DNA) follows simple probability rules dictated by the random distribution of mtDNA molecules at the nucleoid level. This model has been used to explain how mutation levels correlate with the onset of disease phenotype and loss of cellular function. Nonetheless, experimental evidence of heteroplasmy at the nucleoid level is scarce. Here, we report a new method to determine heteroplasmy of individual mitochondrial particles containing one or more nucleoids. The method uses capillary cytometry with laser-induced fluorescence detection to detect individual mitochondrial particles stained with PicoGreen, which makes it possible to quantify the mtDNA copy number of each particle. After detection, one or more particles are collected into polymerase chain reaction (PCR) wells and then subjected to real-time multiplexed PCR amplification. This PCR strategy is suitable to obtain the relative abundance of mutated and wild-type mtDNA. The results obtained here indicate that individual mitochondrial particles and nucleoids contained within these particles are not heteroplasmic. The results presented here suggest that current models of mtDNA segregation and distribution (i.e., heteroplasmic nucleoids) need further consideration.
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