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Yu J, Li X, Qi X, Ding Z, Su S, Yu L, Zhou L, Li Y. Translatomics reveals the role of dietary calcium addition in regulating muscle fat deposition in pigs. Sci Rep 2024; 14:12295. [PMID: 38811812 PMCID: PMC11136974 DOI: 10.1038/s41598-024-62986-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 05/23/2024] [Indexed: 05/31/2024] Open
Abstract
Intramuscular fat (IMF) in pork holds significant importance for economic performance within the pig industry and dietary calcium supplementation enhances the accumulation of intramuscular fat. Additionally, calcium ions inhibit translation and reduce protein synthesis. However, the mechanism by which calcium regulates IMF deposition in muscle through translation remains largely unknown. In this study, we compared the ribosome profiles of the longissimus dorsi muscles of Duroc × Landrace × Large white pigs from the normal calcium (NC) group or calcium supplement (HC) group by Ribo-seq, and RNA-seq. By integrating multiple-omics analysis, we further discovered 437 genes that were transcriptionally unchanged but translationally altered and these genes were significantly enriched in the oxidative phosphorylation signaling pathway. Furthermore, experimental data showed that inhibiting the expression of COX10 and mtND4L increased triglyceride accumulation in C2C12 cells, providing new targets for intramuscular fat deposition. Finally, this work links dietary calcium, translation regulation and IMF deposition, providing a new strategy for both meat quality and economic performance within the pig industry.
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Affiliation(s)
- Jingsu Yu
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China
| | - Xiangling Li
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China
| | - Xinyu Qi
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China
| | - Zhaoxuan Ding
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China
| | - Songtao Su
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China
| | - Lin Yu
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China
| | - Lei Zhou
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China.
| | - Yixing Li
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi Zhuang Autonomous Region, China.
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2
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Averina OA, Kuznetsova SA, Permyakov OA, Sergiev PV. Animal Models of Mitochondrial Diseases Associated with Nuclear Gene Mutations. Acta Naturae 2023; 15:4-22. [PMID: 38234606 PMCID: PMC10790356 DOI: 10.32607/actanaturae.25442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 10/05/2023] [Indexed: 01/19/2024] Open
Abstract
Mitochondrial diseases (MDs) associated with nuclear gene mutations are part of a large group of inherited diseases caused by the suppression of energy metabolism. These diseases are of particular interest, because nuclear genes encode not only most of the structural proteins of the oxidative phosphorylation system (OXPHOS), but also all the proteins involved in the OXPHOS protein import from the cytoplasm and their assembly in mitochondria. Defects in any of these proteins can lead to functional impairment of the respiratory chain, including dysfunction of complex I that plays a central role in cellular respiration and oxidative phosphorylation, which is the most common cause of mitopathologies. Mitochondrial diseases are characterized by an early age of onset and a progressive course and affect primarily energy-consuming tissues and organs. The treatment of MDs should be initiated as soon as possible, but the diagnosis of mitopathologies is extremely difficult because of their heterogeneity and overlapping clinical features. The molecular pathogenesis of mitochondrial diseases is investigated using animal models: i.e. animals carrying mutations causing MD symptoms in humans. The use of mutant animal models opens new opportunities in the study of genes encoding mitochondrial proteins, as well as the molecular mechanisms of mitopathology development, which is necessary for improving diagnosis and developing approaches to drug therapy. In this review, we present the most recent information on mitochondrial diseases associated with nuclear gene mutations and animal models developed to investigate them.
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Affiliation(s)
- O. A. Averina
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
| | - S. A. Kuznetsova
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
| | - O. A. Permyakov
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
| | - P. V. Sergiev
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991 Russian Federation
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3
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Jett KA, Baker ZN, Hossain A, Boulet A, Cobine PA, Ghosh S, Ng P, Yilmaz O, Barreto K, DeCoteau J, Mochoruk K, Ioannou GN, Savard C, Yuan S, Abdalla OH, Lowden C, Kim BE, Cheng HYM, Battersby BJ, Gohil VM, Leary SC. Mitochondrial dysfunction reactivates α-fetoprotein expression that drives copper-dependent immunosuppression in mitochondrial disease models. J Clin Invest 2023; 133:154684. [PMID: 36301669 PMCID: PMC9797342 DOI: 10.1172/jci154684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/26/2022] [Indexed: 02/04/2023] Open
Abstract
Signaling circuits crucial to systemic physiology are widespread, yet uncovering their molecular underpinnings remains a barrier to understanding the etiology of many metabolic disorders. Here, we identified a copper-linked signaling circuit activated by disruption of mitochondrial function in the murine liver or heart that resulted in atrophy of the spleen and thymus and caused a peripheral white blood cell deficiency. We demonstrated that the leukopenia was caused by α-fetoprotein, which required copper and the cell surface receptor CCR5 to promote white blood cell death. We further showed that α-fetoprotein expression was upregulated in several cell types upon inhibition of oxidative phosphorylation. Collectively, our data argue that α-fetoprotein may be secreted by bioenergetically stressed tissue to suppress the immune system, an effect that may explain the recurrent or chronic infections that are observed in a subset of mitochondrial diseases or in other disorders with secondary mitochondrial dysfunction.
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Affiliation(s)
- Kimberly A. Jett
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Zakery N. Baker
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Amzad Hossain
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Aren Boulet
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Paul A. Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Sagnika Ghosh
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Philip Ng
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Orhan Yilmaz
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Kris Barreto
- Department of Laboratory and Pathology Medicine, University of Saskatchewan, Saskatoon, Canada
| | - John DeCoteau
- Department of Laboratory and Pathology Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Karen Mochoruk
- Department of Laboratory and Pathology Medicine, University of Saskatchewan, Saskatoon, Canada
| | - George N. Ioannou
- Division of Gastroenterology,,Research and Development, Veterans Affairs Puget Sound Health Care System and the,Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Christopher Savard
- Division of Gastroenterology,,Research and Development, Veterans Affairs Puget Sound Health Care System and the,Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Sai Yuan
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, USA
| | - Osama H.M.H. Abdalla
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Christopher Lowden
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Byung-Eun Kim
- Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, USA
| | - Hai-Ying Mary Cheng
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | | | - Vishal M. Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Scot C. Leary
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
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4
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Lei X, Liu Q, Qin W, Tong Q, Li Z, Xu W, Liu G, Fu J, Zhang J, Kuang T, Shao Y, Liu C, Fang Y, Cao Z, Yan L, Liu Z, Liu S, Yamamoto H, Mori M, Liang XM, Xu X. TRPM8 contributes to liver regeneration via mitochondrial energy metabolism mediated by PGC1α. Cell Death Dis 2022; 13:1050. [PMID: 36526620 PMCID: PMC9758188 DOI: 10.1038/s41419-022-05475-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
Impairment of liver regeneration leads to severe morbidity in acute and chronic severe liver disease. Transient receptor potential melastain 8 (TRPM8) is involved in a variety of processes, including temperature sensing, ion homeostasis, and cell proliferation. However, whether TRPM8 contributes to liver regeneration is still unclear. We assessed the effect and mechanism of TRPM8 in liver regeneration and hepatocyte proliferation in vivo and in vitro. In this study, we found that TRPM8 deficiency impairs liver regeneration in mice. Mechanistically, the results revealed that mitochondrial energy metabolism was attenuated in livers from TRPM8 knockout (KO) mice. Furthermore, we found that TRPM8 contributes to the proliferation of hepatocytes via PGC1α. Taken together, this study shows that TRPM8 contributes to liver regeneration in mice after hepatectomy. Genetic approaches and pharmacological approaches to regulate TRPM8 activity may be beneficial to the promotion of liver regeneration.
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Affiliation(s)
- Xiaohua Lei
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
- The First Affiliated Hospital, Department of Hepato-Biliary-Pancreatic Surgery, Hengyang Medical School, University of South China, Hengyang, Hunan, People's Republic of China
| | - Qiang Liu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Wei Qin
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Qing Tong
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Zhenghao Li
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Wendi Xu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Guoxing Liu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Jie Fu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Ju Zhang
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Tao Kuang
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Yaoli Shao
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Chun Liu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Yu Fang
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Zhenyu Cao
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Likun Yan
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Zhiqiang Liu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Siyuan Liu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Hirofumi Yamamoto
- Department of Surgery, Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Masaki Mori
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Xin M Liang
- Wellman Center for Photomedicine, Division of Hematology and Oncology, Division of Endocrinology, Massachusetts General Hospital, VA Boston Healthcare System, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Xundi Xu
- Hunan Provincial Key Laboratory of Hepatobiliary Disease Research & Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
- Department of general surgery. Southern China Hospital, Health Science Center, Shenzhen University, Shenzhen, People's Republic of China.
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5
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Lesner NP, Wang X, Chen Z, Frank A, Menezes CJ, House S, Shelton SD, Lemoff A, McFadden DG, Wansapura J, DeBerardinis RJ, Mishra P. Differential requirements for mitochondrial electron transport chain components in the adult murine liver. eLife 2022; 11:e80919. [PMID: 36154948 PMCID: PMC9648974 DOI: 10.7554/elife.80919] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/23/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial electron transport chain (ETC) dysfunction due to mutations in the nuclear or mitochondrial genome is a common cause of metabolic disease in humans and displays striking tissue specificity depending on the affected gene. The mechanisms underlying tissue-specific phenotypes are not understood. Complex I (cI) is classically considered the entry point for electrons into the ETC, and in vitro experiments indicate that cI is required for basal respiration and maintenance of the NAD+/NADH ratio, an indicator of cellular redox status. This finding has largely not been tested in vivo. Here, we report that mitochondrial complex I is dispensable for homeostasis of the adult mouse liver; animals with hepatocyte-specific loss of cI function display no overt phenotypes or signs of liver damage, and maintain liver function, redox and oxygen status. Further analysis of cI-deficient livers did not reveal significant proteomic or metabolic changes, indicating little to no compensation is required in the setting of complex I loss. In contrast, complex IV (cIV) dysfunction in adult hepatocytes results in decreased liver function, impaired oxygen handling, steatosis, and liver damage, accompanied by significant metabolomic and proteomic perturbations. Our results support a model whereby complex I loss is tolerated in the mouse liver because hepatocytes use alternative electron donors to fuel the mitochondrial ETC.
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Affiliation(s)
- Nicholas P Lesner
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Xun Wang
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Zhenkang Chen
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Anderson Frank
- Department of Biochemistry, University of Texas Southwestern Medical CenterDallasUnited States
| | - Cameron J Menezes
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Sara House
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Spencer D Shelton
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Andrew Lemoff
- Department of Biochemistry, University of Texas Southwestern Medical CenterDallasUnited States
| | - David G McFadden
- Department of Biochemistry, University of Texas Southwestern Medical CenterDallasUnited States
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical CenterDallasUnited States
| | - Janaka Wansapura
- Advanced Imaging Research Center, University of Texas Southwestern Medical CenterDallasUnited States
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Pediatrics, University of Texas Southwestern Medical CenterDallasUnited States
- Howard Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Prashant Mishra
- Children's Medical Center Research Institute, University of Texas Southwestern Medical CenterDallasUnited States
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Pediatrics, University of Texas Southwestern Medical CenterDallasUnited States
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6
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Wang X, Shelton SD, Bordieanu B, Frank AR, Yi Y, Venigalla SSK, Gu Z, Lenser NP, Glogauer M, Chandel NS, Zhao H, Zhao Z, McFadden DG, Mishra P. Scinderin promotes fusion of electron transport chain dysfunctional muscle stem cells with myofibers. NATURE AGING 2022; 2:155-169. [PMID: 35342888 PMCID: PMC8954567 DOI: 10.1038/s43587-021-00164-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Muscle stem cells (MuSCs) experience age-associated declines in number and function, accompanied by mitochondrial electron transport chain (ETC) dysfunction and increased reactive oxygen species (ROS). The source of these changes, and how MuSCs respond to mitochondrial dysfunction, is unknown. We report here that in response to mitochondrial ROS, murine MuSCs directly fuse with neighboring myofibers; this phenomenon removes ETC-dysfunctional MuSCs from the stem cell compartment. MuSC-myofiber fusion is dependent on the induction of Scinderin, which promotes formation of actin-dependent protrusions required for membrane fusion. During aging, we find that the declining MuSC population accumulates mutations in the mitochondrial genome, but selects against dysfunctional variants. In the absence of clearance by Scinderin, the decline in MuSC numbers during aging is repressed; however, ETC-dysfunctional MuSCs are retained and can regenerate dysfunctional myofibers. We propose a model in which ETC-dysfunctional MuSCs are removed from the stem cell compartment by fusing with differentiated tissue.
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Affiliation(s)
- Xun Wang
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Spencer D Shelton
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Bogdan Bordieanu
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Present Address: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425 USA
| | - Anderson R Frank
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Internal Medicine, Division of Endocrinology, Program in Molecular Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Yating Yi
- Department of Comprehensive Dentistry, College of Dentistry, Texas A&M University, Dallas, TX 75246, USA
- Present address: State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041 China
| | - Siva Sai Krishna Venigalla
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Zhimin Gu
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nicholas P Lenser
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Present address: Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael Glogauer
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Navdeep S Chandel
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Biochemistry & Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Hu Zhao
- Department of Comprehensive Dentistry, College of Dentistry, Texas A&M University, Dallas, TX 75246, USA
- Present address: The Chinese Institute for Brain Research, Beijing, China
| | - Zhiyu Zhao
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David G McFadden
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Internal Medicine, Division of Endocrinology, Program in Molecular Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Prashant Mishra
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390
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7
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Luo P, Yan H, Du J, Chen X, Shao J, Zhang Y, Xu Z, Jin Y, Lin N, Yang B, He Q. PLK1 (polo like kinase 1)-dependent autophagy facilitates gefitinib-induced hepatotoxicity by degrading COX6A1 (cytochrome c oxidase subunit 6A1). Autophagy 2021; 17:3221-3237. [PMID: 33315519 PMCID: PMC8526032 DOI: 10.1080/15548627.2020.1851492] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 01/01/2023] Open
Abstract
Liver dysfunction is an outstanding dose-limiting toxicity of gefitinib, an EGFR (epidermal growth factor receptor)-tyrosine kinase inhibitor (TKI), in the treatment of EGFR mutation-positive non-small cell lung cancer (NSCLC). We aimed to elucidate the mechanisms underlying gefitinib-induced hepatotoxicity, and provide potentially effective intervention strategy. We discovered that gefitinib could sequentially activate macroautophagy/autophagy and apoptosis in hepatocytes. The inhibition of autophagy alleviated gefitinib-induced apoptosis, whereas the suppression of apoptosis failed to lessen gefitinib-induced autophagy. Moreover, liver-specific Atg7+/- heterozygous mice showed less severe liver injury than vehicle, suggesting that autophagy is involved in the gefitinib-promoted hepatotoxicity. Mechanistically, gefitinib selectively degrades the important anti-apoptosis factor COX6A1 (cytochrome c oxidase subunit 6A1) in the autophagy-lysosome pathway. The gefitinib-induced COX6A1 reduction impairs mitochondrial respiratory chain complex IV (RCC IV) function, which in turn activates apoptosis, hence causing liver injury. Notably, this autophagy-promoted apoptosis is dependent on PLK1 (polo like kinase 1). Both AAV8-mediated Plk1 knockdown and PLK1 inhibitor BI-2536 could mitigate the gefitinib-induced hepatotoxicity in vivo by abrogating the autophagic degradation of the COX6A1 protein. In addition, PLK1 inhibition could not compromise the anti-cancer activity of gefitinib. In conclusion, our findings reveal the gefitinib-hepatotoxicity pathway, wherein autophagy promotes apoptosis through COX6A1 degradation, and highlight pharmacological inhibition of PLK1 as an attractive therapeutic approach toward improving the safety of gefitinib-based cancer therapy.Abbreviations: 3-MA: 3-methyladenine; AAV8: adeno-associated virus serotype 8; ATG5: autophagy related 5; ATG7: autophagy related 7; B2M: beta-2-microglobulin; CCCP: carbonyl cyanide m-chlorophenylhydrazone; CHX: cycloheximide; COX6A1: cytochrome c oxidase subunit 6A1; c-PARP: cleaved poly(ADP-ribose) polymerase; CQ: chloroquine; GOT1/AST: glutamic-oxaloacetic transaminase 1, soluble; GPT/ALT: glutamic pyruvic transaminase, soluble; HBSS: Hanks´ balanced salt solution; H&E: hematoxylin and eosin; MAP1LC3/LC3: microtubule associated proteins 1 light chain 3; PLK1: polo like kinase 1; RCC IV: respiratory chain complex IV; ROS: reactive oxygen species; TUBB8: tubulin beta 8 class VIII.
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Affiliation(s)
- Peihua Luo
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Hao Yan
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jiangxia Du
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xueqin Chen
- Department of Oncology, Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People´s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jinjin Shao
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Ying Zhang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhifei Xu
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Ying Jin
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Nengming Lin
- Laboratory of Clinical Pharmacology, Affiliated Hangzhou First People´s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Bo Yang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Qiaojun He
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
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8
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Garcia S, Saldana-Caboverde A, Anwar M, Raval AP, Nissanka N, Pinto M, Moraes CT, Diaz F. Enhanced glycolysis and GSK3 inactivation promote brain metabolic adaptations following neuronal mitochondrial stress. Hum Mol Genet 2021; 31:692-704. [PMID: 34559217 DOI: 10.1093/hmg/ddab282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/10/2021] [Accepted: 09/17/2021] [Indexed: 11/14/2022] Open
Abstract
We analyzed early brain metabolic adaptations in response to mitochondrial dysfunction in a mouse model of mitochondrial encephalopathy with complex IV deficiency (neuron specific COX10 KO). In this mouse model the onset of the mitochondrial defect did not coincide with immediate cell death suggesting early adaptive metabolic responses to compensate for the energetic deficit. Metabolomic analysis in the knockout mice revealed increased levels of glycolytic and pentose phosphate pathway intermediates, amino acids and lysolipids. Glycolysis was modulated by enhanced activity of glycolytic enzymes, and not by their overexpression, suggesting the importance of post-translational modifications in the adaptive response. GSK3 inactivation was the most upstream regulation identified, implying that it is a key event in this adaptive mechanism. Because neurons are thought not to rely on glycolysis for ATP production in normal conditions, our results indicate that neurons still maintain their ability to upregulate this pathway when under mitochondrial respiration stress.
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Affiliation(s)
- Sofia Garcia
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Amy Saldana-Caboverde
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Mir Anwar
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Ami Pravinkant Raval
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Nadee Nissanka
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Milena Pinto
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Carlos Torres Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Francisca Diaz
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
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9
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Mitochondrial respiration controls neoangiogenesis during wound healing and tumour growth. Nat Commun 2020; 11:3653. [PMID: 32694534 PMCID: PMC7374592 DOI: 10.1038/s41467-020-17472-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/30/2020] [Indexed: 12/29/2022] Open
Abstract
The vasculature represents a highly plastic compartment, capable of switching from a quiescent to an active proliferative state during angiogenesis. Metabolic reprogramming in endothelial cells (ECs) thereby is crucial to cover the increasing cellular energy demand under growth conditions. Here we assess the impact of mitochondrial bioenergetics on neovascularisation, by deleting cox10 gene encoding an assembly factor of cytochrome c oxidase (COX) specifically in mouse ECs, providing a model for vasculature-restricted respiratory deficiency. We show that EC-specific cox10 ablation results in deficient vascular development causing embryonic lethality. In adult mice induction of EC-specific cox10 gene deletion produces no overt phenotype. However, the angiogenic capacity of COX-deficient ECs is severely compromised under energetically demanding conditions, as revealed by significantly delayed wound-healing and impaired tumour growth. We provide genetic evidence for a requirement of mitochondrial respiration in vascular endothelial cells for neoangiogenesis during development, tissue repair and cancer. During angiogenesis the vasculature switches from a quiescent to a proliferative state. Here the authors show that mitochondrial respiration in endothelial cells controls angiogenesis during development, tumour growth and tissue repair.
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10
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Jestin M, Kapnick SM, Tarasenko TN, Burke CT, Zerfas PM, Diaz F, Vernon H, Singh LN, Sokol RJ, McGuire PJ. Mitochondrial disease disrupts hepatic allostasis and lowers the threshold for immune-mediated liver toxicity. Mol Metab 2020; 37:100981. [PMID: 32283081 PMCID: PMC7167504 DOI: 10.1016/j.molmet.2020.100981] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 03/03/2020] [Accepted: 03/16/2020] [Indexed: 12/23/2022] Open
Abstract
Objective In individuals with mitochondrial disease, respiratory viral infection can result in metabolic decompensation with mitochondrial hepatopathy. Here, we used a mouse model of liver-specific Complex IV deficiency to study hepatic allostasis during respiratory viral infection. Methods Mice with hepatic cytochrome c oxidase deficiency (LivCox10−/−) were infected with aerosolized influenza, A/PR/8 (PR8), and euthanized on day five after infection following three days of symptoms. This time course is marked by a peak in inflammatory cytokines and mimics the timing of a common clinical scenario in which caregivers may first attempt to manage the illness at home before seeking medical attention. Metabolic decompensation and mitochondrial hepatopathy in mice were characterized by serum hepatic testing, histology, electron microscopy, biochemistry, metabolomics, and bioenergetic profiling. Results Following influenza infection, LivCox10−/− mice displayed marked liver disease including hepatitis, enlarged mitochondria with cristae loss, and hepatic steatosis. This pathophysiology was associated with viremia. Primary hepatocytes from LivCox10−/− mice cocultured with WT Kupffer cells in the presence of PR8 showed enhanced lipid accumulation. Treatment of hepatocytes with recombinant TNFα implicated Kupffer cell-derived TNFα as a precipitant of steatosis in LivCox10−/− mice. Eliminating Kupffer cells or blocking TNFα in vivo during influenza infection mitigated the steatosis and mitochondrial morphologic changes. Conclusions Taken together, our data shift the narrative of metabolic decompensation in mitochondrial hepatopathy beyond the bioenergetic costs of infection to include an underlying susceptibility to immune-mediated damage. Moreover, our work suggests that immune modulation during metabolic decompensation in mitochondrial disease represents a future viable treatment strategy needing further exploration. Influenza infection leads to worsening mitochondrial function and steatohepatitis in a model of mitochondrial hepatopathy. Kupffer cells may mediate this damage by the uptake of influenza virus and the secretion of TNFa. Hepatocytes affected by mitochondrial disease have a lower threshold for immune mediated toxicity by TNFa. Modulating the immune response leads to an improvement in the phenotype.
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Affiliation(s)
- Maxim Jestin
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Senta M Kapnick
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Tatyana N Tarasenko
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Cassidy T Burke
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Patricia M Zerfas
- Office of Research Services, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Francisca Diaz
- University of Miami, Department of Neurology, Miller School of Medicine, Miami, FL, 33136, USA
| | - Hilary Vernon
- Kennedy Krieger Institute, Johns Hopkins Medical Center, Baltimore, MD, 21205, USA
| | - Larry N Singh
- Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Ronald J Sokol
- Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO 80045, USA
| | - Peter J McGuire
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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11
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Ruiz M, Cuillerier A, Daneault C, Deschênes S, Frayne IR, Bouchard B, Forest A, Legault JT, Vaz FM, Rioux JD, Burelle Y, Des Rosiers C. Lipidomics unveils lipid dyshomeostasis and low circulating plasmalogens as biomarkers in a monogenic mitochondrial disorder. JCI Insight 2019; 4:123231. [PMID: 31341105 DOI: 10.1172/jci.insight.123231] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 05/31/2019] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial dysfunction characterizes many rare and common age-associated diseases. The biochemical consequences, underlying clinical manifestations, and potential therapeutic targets, remain to be better understood. We tested the hypothesis that lipid dyshomeostasis in mitochondrial disorders goes beyond mitochondrial fatty acid β-oxidation, particularly in liver. This was achieved using comprehensive untargeted and targeted lipidomics in a case-control cohort of patients with Leigh syndrome French-Canadian variant (LSFC), a mitochondrial disease caused by mutations in LRPPRC, and in mice harboring liver-specific inactivation of Lrpprc (H-Lrpprc-/-). We discovered a plasma lipid signature discriminating LSFC patients from controls encompassing lower levels of plasmalogens and conjugated bile acids, which suggest perturbations in peroxisomal lipid metabolism. This premise was reinforced in H-Lrpprc-/- mice, which compared with littermates recapitulated a similar, albeit stronger peroxisomal metabolic signature in plasma and liver including elevated levels of very-long-chain acylcarnitines. These mice also presented higher transcript levels for hepatic markers of peroxisome proliferation in addition to lipid remodeling reminiscent of nonalcoholic fatty liver diseases. Our study underscores the value of lipidomics to unveil unexpected mechanisms underlying lipid dyshomeostasis ensuing from mitochondrial dysfunction herein implying peroxisomes and liver, which likely contribute to the pathophysiology of LSFC, but also other rare and common mitochondrial diseases.
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Affiliation(s)
- Matthieu Ruiz
- Department of Nutrition and.,Department of Medicine, Université de Montréal, Montreal, Quebec, Canada.,Montreal Heart Institute Research Center, Montreal, Quebec, Canada
| | - Alexanne Cuillerier
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences and Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Sonia Deschênes
- Montreal Heart Institute Research Center, Montreal, Quebec, Canada
| | | | | | - Anik Forest
- Montreal Heart Institute Research Center, Montreal, Quebec, Canada
| | | | | | - Frederic M Vaz
- Amsterdam UMC, University of Amsterdam, Laboratory Genetic Metabolic Diseases, Core Facility Metabolomics, Amsterdam Gastroenterology & Metabolism, Meibergdreef, Amsterdam, Netherlands
| | - John D Rioux
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada.,Montreal Heart Institute Research Center, Montreal, Quebec, Canada
| | - Yan Burelle
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences and Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Christine Des Rosiers
- Department of Nutrition and.,Montreal Heart Institute Research Center, Montreal, Quebec, Canada
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12
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Becker C, Kukat A, Szczepanowska K, Hermans S, Senft K, Brandscheid CP, Maiti P, Trifunovic A. CLPP deficiency protects against metabolic syndrome but hinders adaptive thermogenesis. EMBO Rep 2018; 19:embr.201745126. [PMID: 29588285 DOI: 10.15252/embr.201745126] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 02/26/2018] [Accepted: 02/27/2018] [Indexed: 12/21/2022] Open
Abstract
Mitochondria are fundamental for cellular metabolism as they are both a source and a target of nutrient intermediates originating from converging metabolic pathways, and their role in the regulation of systemic metabolism is increasingly recognized. Thus, maintenance of mitochondrial homeostasis is indispensable for a functional energy metabolism of the whole organism. Here, we report that loss of the mitochondrial matrix protease CLPP results in a lean phenotype with improved glucose homeostasis. Whole-body CLPP-deficient mice are protected from diet-induced obesity and insulin resistance, which was not present in mouse models with either liver- or muscle-specific depletion of CLPP However, CLPP ablation also leads to a decline in brown adipocytes function leaving mice unable to cope with a cold-induced stress due to non-functional adaptive thermogenesis. These results demonstrate a critical role for CLPP in different metabolic stress conditions such as high-fat diet feeding and cold exposure providing tools to understand pathologies with deregulated Clpp expression and novel insights into therapeutic approaches against metabolic dysfunctions linked to mitochondrial diseases.
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Affiliation(s)
- Christina Becker
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Alexandra Kukat
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Karolina Szczepanowska
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Steffen Hermans
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Katharina Senft
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Christoph Paul Brandscheid
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Priyanka Maiti
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany
| | - Aleksandra Trifunovic
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, Cologne, Germany .,Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
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13
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Cuillerier A, Honarmand S, Cadete VJJ, Ruiz M, Forest A, Deschênes S, Beauchamp C, Charron G, Rioux JD, Des Rosiers C, Shoubridge EA, Burelle Y. Loss of hepatic LRPPRC alters mitochondrial bioenergetics, regulation of permeability transition and trans-membrane ROS diffusion. Hum Mol Genet 2018; 26:3186-3201. [PMID: 28575497 DOI: 10.1093/hmg/ddx202] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 05/19/2017] [Indexed: 12/19/2022] Open
Abstract
The French-Canadian variant of Leigh Syndrome (LSFC) is an autosomal recessive oxidative phosphorylation (OXPHOS) disorder caused by a mutation in LRPPRC, coding for a protein involved in the stability of mitochondrially-encoded mRNAs. Low levels of LRPPRC are present in all patient tissues, but result in a disproportionately severe OXPHOS defect in the brain and liver, leading to unpredictable subacute metabolic crises. To investigate the impact of the OXPHOS defect in the liver, we analyzed the mitochondrial phenotype in mice harboring an hepatocyte-specific inactivation of Lrpprc. Loss of LRPPRC in the liver caused a generalized growth delay, and typical histological features of mitochondrial hepatopathy. At the molecular level, LRPPRC deficiency caused destabilization of polyadenylated mitochondrial mRNAs, altered mitochondrial ultrastructure, and a severe complex IV (CIV) and ATP synthase (CV) assembly defect. The impact of LRPPRC deficiency was not limited to OXPHOS, but also included impairment of long-chain fatty acid oxidation, a striking dysregulation of the mitochondrial permeability transition pore, and an unsuspected alteration of trans-membrane H2O2 diffusion, which was traced to the ATP synthase assembly defect, and to changes in the lipid composition of mitochondrial membranes. This study underscores the value of mitochondria phenotyping to uncover complex and unexpected mechanisms contributing to the pathophysiology of mitochondrial disorders.
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Affiliation(s)
| | - Shamisa Honarmand
- Department of Human Genetics, Montreal Neurological Institute McGill University, Montreal, QC H3A 2B4, Canada
| | | | - Matthieu Ruiz
- Research Center, Montreal Heart Institute, Montreal, QC H1T 1C8, Canada
| | - Anik Forest
- Research Center, Montreal Heart Institute, Montreal, QC H1T 1C8, Canada
| | - Sonia Deschênes
- Faculty of Pharmacy, University of Montreal, Montreal, QC H3C 3J7, Canada.,Faculty of Medicine and Department of Nutrition, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | | | | | - Guy Charron
- Research Center, Montreal Heart Institute, Montreal, QC H1T 1C8, Canada
| | - John D Rioux
- Research Center, Montreal Heart Institute, Montreal, QC H1T 1C8, Canada
| | - Christine Des Rosiers
- Research Center, Montreal Heart Institute, Montreal, QC H1T 1C8, Canada.,Faculty of Medicine and Department of Nutrition, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Eric A Shoubridge
- Department of Human Genetics, Montreal Neurological Institute McGill University, Montreal, QC H3A 2B4, Canada
| | - Yan Burelle
- Faculty of Pharmacy, University of Montreal, Montreal, QC H3C 3J7, Canada
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14
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Respiration-Deficient Astrocytes Survive As Glycolytic Cells In Vivo. J Neurosci 2017; 37:4231-4242. [PMID: 28314814 DOI: 10.1523/jneurosci.0756-16.2017] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 01/22/2017] [Accepted: 02/16/2017] [Indexed: 11/21/2022] Open
Abstract
Neurons and glial cells exchange energy-rich metabolites and it has been suggested, originally based on in vitro data, that astrocytes provide lactate to glutamatergic synapses ("lactate shuttle"). Here, we have studied astrocytes that lack mitochondrial respiration in vitro and in vivo A novel mouse mutant (GLASTCreERT2::Cox10flox/flox) was generated, in which the administration of tamoxifen causes mutant astrocytes to fail in the assembly of mitochondrial cytochrome c oxidase (COX). Focusing on cerebellar Bergmann glia (BG) cells, which exhibit the highest rate of Cre-mediated recombination, we found a normal density of viable astrocytes even 1 year after tamoxifen-induced Cox10 gene targeting. Our data show that BG cells, and presumably all astrocytes, can survive by aerobic glycolysis for an extended period of time in the absence of glial pathology or unspecific signs of neurodegeneration.SIGNIFICANCE STATEMENT When astrocytes are placed into culture, they import glucose and release lactate, an energy-rich metabolite readily metabolized by neurons. This observation led to the "glia-to-neuron lactate shuttle hypothesis," but in vivo evidence for this hypothesis is weak. To study astroglial energy metabolism and the directionality of lactate flux, we generated conditional Cox10 mouse mutants lacking mitochondrial respiration in astrocytes, which forces these cells to survive by aerobic glycolysis. Here, we report that these mice are fully viable in the absence of any signs of glial or neuronal loss, suggesting that astrocytes are naturally glycolytic cells.
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15
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Schatton D, Pla-Martin D, Marx MC, Hansen H, Mourier A, Nemazanyy I, Pessia A, Zentis P, Corona T, Kondylis V, Barth E, Schauss AC, Velagapudi V, Rugarli EI. CLUH regulates mitochondrial metabolism by controlling translation and decay of target mRNAs. J Cell Biol 2017; 216:675-693. [PMID: 28188211 PMCID: PMC5350512 DOI: 10.1083/jcb.201607019] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 12/06/2016] [Accepted: 01/06/2017] [Indexed: 12/21/2022] Open
Abstract
Mitochondria are essential organelles that host crucial metabolic pathways and produce adenosine triphosphate. The mitochondrial proteome is heterogeneous among tissues and can dynamically change in response to different metabolic conditions. Although the transcriptional programs that govern mitochondrial biogenesis and respiratory function are well known, posttranscriptional regulatory mechanisms remain unclear. In this study, we show that the cytosolic RNA-binding protein clustered mitochondria homologue (CLUH) regulates the expression of a mitochondrial protein network supporting key metabolic programs required under nutrient deprivation. CLUH exerts its function by controlling the stability and translation of target messenger RNAs. In the absence of Cluh, mitochondria are severely depleted of crucial enzymes involved in catabolic energy-converting pathways. CLUH preserves oxidative mitochondrial function and glucose homeostasis, thus preventing death at the fetal-neonatal transition. In the adult liver, CLUH ensures maximal respiration capacity and the metabolic response to starvation. Our results shed new light on the posttranscriptional mechanisms controlling the expression of mitochondrial proteins and suggest novel strategies to tailor mitochondrial function to physiological and pathological conditions.
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Affiliation(s)
- Désirée Schatton
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - David Pla-Martin
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Marie-Charlotte Marx
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Henriette Hansen
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Arnaud Mourier
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Ivan Nemazanyy
- Paris Descartes University, Sorbonne Paris Cité, 75006 Paris, France
| | - Alberto Pessia
- Metabolomics Unit, Institute for Molecular Medicine Finland, University of Helsinki, 00290 Helsinki, Finland
| | - Peter Zentis
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Teresa Corona
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Vangelis Kondylis
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Esther Barth
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Astrid C Schauss
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Vidya Velagapudi
- Metabolomics Unit, Institute for Molecular Medicine Finland, University of Helsinki, 00290 Helsinki, Finland
| | - Elena I Rugarli
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
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16
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Ino D, Iino M. Schwann cell mitochondria as key regulators in the development and maintenance of peripheral nerve axons. Cell Mol Life Sci 2017; 74:827-835. [PMID: 27638763 PMCID: PMC11107563 DOI: 10.1007/s00018-016-2364-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/09/2016] [Indexed: 01/13/2023]
Abstract
Formation of myelin sheaths by Schwann cells (SCs) enables rapid and efficient transmission of action potentials in peripheral axons, and disruption of myelination results in disorders that involve decreased sensory and motor functions. Given that construction of SC myelin requires high levels of lipid and protein synthesis, mitochondria, which are pivotal in cellular metabolism, may be potential regulators of the formation and maintenance of SC myelin. Supporting this notion, abnormal mitochondria are found in SCs of neuropathic peripheral nerves in both human patients and the relevant animal models. However, evidence for the importance of SC mitochondria in myelination has been limited, until recently. Several studies have recently used genetic approaches that allow SC-specific ablation of mitochondrial metabolic activity in living animals to show the critical roles of SC mitochondria in the development and maintenance of peripheral nerve axons. Here, we review current knowledge about the involvement of SC mitochondria in the formation and dysfunction of myelinated axons in the peripheral nervous system.
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Affiliation(s)
- Daisuke Ino
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Laboratory for Cell Polarity Regulation, RIKEN Quantitative Biology Center, 6-2-3, Furuedai, Suita, Osaka, 565-0874, Japan
| | - Masamitsu Iino
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, 30-1, Oyaguchi kami-cho, Itabashi-ku, Tokyo, 173-8610, Japan.
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17
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Kwanten WJ, Vandewynckel YP, Martinet W, De Winter BY, Michielsen PP, Van Hoof VO, Driessen A, Timmermans JP, Bedossa P, Van Vlierberghe H, Francque SM. Hepatocellular autophagy modulates the unfolded protein response and fasting-induced steatosis in mice. Am J Physiol Gastrointest Liver Physiol 2016; 311:G599-G609. [PMID: 27514483 PMCID: PMC5142201 DOI: 10.1152/ajpgi.00418.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 08/05/2016] [Indexed: 01/31/2023]
Abstract
Autophagy and the unfolded protein response (UPR) are key cellular homeostatic mechanisms and are both involved in liver diseases, including nonalcoholic fatty liver disease (NAFLD). Although increasing but conflicting results link these mechanisms to lipid metabolism, their role and potential cross talk herein have been poorly investigated. Therefore, we assessed the effects of hepatocyte-specific autophagy deficiency on liver parenchyma, the UPR, and lipid metabolism. Adult hepatocellular-specific autophagy-deficient mice (Atg7F/FAlb-Cre+) were compared with their autophagy-competent littermates (Atg7+/+Alb-Cre+). Livers were analyzed by electron microscopy, histology, real-time qPCR, and Western blotting. Atg7F/FAlb-Cre+ mice developed hepatomegaly with significant parenchymal injury, as shown by inflammatory infiltrates, hepatocellular apoptosis, pericellular fibrosis, and a pronounced ductular reaction. Surprisingly, the UPR exhibited a pathway-selective pattern upon autophagy deficiency. The activity of the adaptive activating transcription factor 6 (ATF6) pathway was abolished, whereas the proapoptotic protein kinase RNA-like ER kinase pathway was increased compared with Atg7+/+Alb-Cre+ mice. The inositol-requiring enzyme-1α signal was unaltered. Fasting-induced steatosis was absent in Atg7F/FAlb-Cre+ mice. Remarkably, some isolated islands of fat-containing and autophagy-competent cells were observed in these livers. Hepatocellular autophagy is essential for parenchymal integrity in mice. Moreover, in the case of autophagy deficiency, the three different UPR branches are pathway selectively modulated. Attenuation of the ATF6 pathway might explain the observed impairment of fasting-induced steatosis. Finally, autophagy and lipid droplets are directly linked to each other.
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Affiliation(s)
- Wilhelmus J. Kwanten
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium;
| | | | - Wim Martinet
- 3Laboratory of Physiopharmacology, University of Antwerp, Antwerp, Belgium;
| | - Benedicte Y. De Winter
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium;
| | - Peter P. Michielsen
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium; ,4Department of Gastroenterology and Hepatology, Antwerp University Hospital, Edegem (Antwerp), Belgium;
| | - Viviane O. Van Hoof
- 5Department of Clinical Chemistry, Antwerp University Hospital, Edegem (Antwerp), Belgium;
| | - Ann Driessen
- 6Department of Pathology, Antwerp University Hospital/University of Antwerp, Edegem (Antwerp), Belgium;
| | | | - Pierre Bedossa
- 8Department of Pathology, Beaujon Hospital, Assistance Publique-Hôpitaux de Paris, Paris University-Denis Diderot, Clichy, France
| | - Hans Van Vlierberghe
- 2Department of Hepatology and Gastroenterology, Ghent University, Ghent, Belgium;
| | - Sven M. Francque
- 1Laboratory of Experimental Medicine and Pediatrics (LEMP), University of Antwerp, Antwerp, Belgium; ,4Department of Gastroenterology and Hepatology, Antwerp University Hospital, Edegem (Antwerp), Belgium;
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18
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Rak M, Bénit P, Chrétien D, Bouchereau J, Schiff M, El-Khoury R, Tzagoloff A, Rustin P. Mitochondrial cytochrome c oxidase deficiency. Clin Sci (Lond) 2016; 130:393-407. [PMID: 26846578 PMCID: PMC4948581 DOI: 10.1042/cs20150707] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
As with other mitochondrial respiratory chain components, marked clinical and genetic heterogeneity is observed in patients with a cytochrome c oxidase deficiency. This constitutes a considerable diagnostic challenge and raises a number of puzzling questions. So far, pathological mutations have been reported in more than 30 genes, in both mitochondrial and nuclear DNA, affecting either structural subunits of the enzyme or proteins involved in its biogenesis. In this review, we discuss the possible causes of the discrepancy between the spectacular advances made in the identification of the molecular bases of cytochrome oxidase deficiency and the lack of any efficient treatment in diseases resulting from such deficiencies. This brings back many unsolved questions related to the frequent delay of clinical manifestation, variable course and severity, and tissue-involvement often associated with these diseases. In this context, we stress the importance of studying different models of these diseases, but also discuss the limitations encountered in most available disease models. In the future, with the possible exception of replacement therapy using genes, cells or organs, a better understanding of underlying mechanism(s) of these mitochondrial diseases is presumably required to develop efficient therapy.
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Affiliation(s)
- Malgorzata Rak
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 1141, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Faculté de Médecine Denis Diderot, Université Paris Diderot-Paris 7, Site Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France
| | - Paule Bénit
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 1141, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Faculté de Médecine Denis Diderot, Université Paris Diderot-Paris 7, Site Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France
| | - Dominique Chrétien
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 1141, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Faculté de Médecine Denis Diderot, Université Paris Diderot-Paris 7, Site Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France
| | - Juliette Bouchereau
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 1141, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Faculté de Médecine Denis Diderot, Université Paris Diderot-Paris 7, Site Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France
| | - Manuel Schiff
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 1141, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Faculté de Médecine Denis Diderot, Université Paris Diderot-Paris 7, Site Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Reference Center for Inherited Metabolic Diseases, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, 48 Boulevard Sérurier, 75019 Paris, France
| | - Riyad El-Khoury
- American University of Beirut Medical Center, Department of Pathology and Laboratory Medicine, Cairo Street, Hamra, Beirut, Lebanon
| | - Alexander Tzagoloff
- Biological Sciences Department, Columbia University, New York, NY 10027, U.S.A
| | - Pierre Rustin
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 1141, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France Faculté de Médecine Denis Diderot, Université Paris Diderot-Paris 7, Site Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France
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19
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Cytochrome c oxidase deficiency accelerates mitochondrial apoptosis by activating ceramide synthase 6. Cell Death Dis 2015; 6:e1691. [PMID: 25766330 PMCID: PMC4385940 DOI: 10.1038/cddis.2015.62] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 02/03/2015] [Accepted: 02/09/2015] [Indexed: 12/21/2022]
Abstract
Although numerous pathogenic changes within the mitochondrial respiratory chain (RC) have been associated with an elevated occurrence of apoptosis within the affected tissues, the mechanistic insight into how mitochondrial dysfunction initiates apoptotic cell death is still unknown. In this study, we show that the specific alteration of the cytochrome c oxidase (COX), representing a common defect found in mitochondrial diseases, facilitates mitochondrial apoptosis in response to oxidative stress. Our data identified an increased ceramide synthase 6 (CerS6) activity as an important pro-apoptotic response to COX dysfunction induced either by chemical or genetic approaches. The elevated CerS6 activity resulted in accumulation of the pro-apoptotic C16 : 0 ceramide, which facilitates the mitochondrial apoptosis in response to oxidative stress. Accordingly, inhibition of CerS6 or its specific knockdown diminished the increased susceptibility of COX-deficient cells to oxidative stress. Our results provide new insights into how mitochondrial RC dysfunction mechanistically interferes with the apoptotic machinery. On the basis of its pivotal role in regulating cell death upon COX dysfunction, CerS6 might potentially represent a novel target for therapeutic intervention in mitochondrial diseases caused by COX dysfunction.
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20
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Hlynialuk CJ, Ling B, Baker ZN, Cobine PA, Yu LD, Boulet A, Wai T, Hossain A, El Zawily AM, McFie PJ, Stone SJ, Diaz F, Moraes CT, Viswanathan D, Petris MJ, Leary SC. The Mitochondrial Metallochaperone SCO1 Is Required to Sustain Expression of the High-Affinity Copper Transporter CTR1 and Preserve Copper Homeostasis. Cell Rep 2015; 10:933-943. [PMID: 25683716 DOI: 10.1016/j.celrep.2015.01.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 12/15/2014] [Accepted: 01/08/2015] [Indexed: 02/03/2023] Open
Abstract
Human SCO1 fulfills essential roles in cytochrome c oxidase (COX) assembly and the regulation of copper (Cu) homeostasis, yet it remains unclear why pathogenic mutations in this gene cause such clinically heterogeneous forms of disease. Here, we establish a Sco1 mouse model of human disease and show that ablation of Sco1 expression in the liver is lethal owing to severe COX and Cu deficiencies. We further demonstrate that the Cu deficiency is explained by a functional connection between SCO1 and CTR1, the high-affinity transporter that imports Cu into the cell. CTR1 is rapidly degraded in the absence of SCO1 protein, and we show that its levels are restored in Sco1-/- mouse embryonic fibroblasts upon inhibition of the proteasome. These data suggest that mitochondrial signaling through SCO1 provides a post-translational mechanism to regulate CTR1-dependent Cu import into the cell, and they further underpin the importance of mitochondria in cellular Cu homeostasis.
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Affiliation(s)
| | - Binbing Ling
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Zakery N Baker
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Lisa D Yu
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Aren Boulet
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Timothy Wai
- Institute for Genetics, University of Cologne, 50931 Cologne, Germany
| | - Amzad Hossain
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Amr M El Zawily
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; Faculty of Science, Damanhour University, Damanhour 22516, Egypt
| | - Pamela J McFie
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Scot J Stone
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Francisca Diaz
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Carlos T Moraes
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Deepa Viswanathan
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Michael J Petris
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Scot C Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
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21
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Torraco A, Peralta S, Iommarini L, Diaz F. Mitochondrial Diseases Part I: mouse models of OXPHOS deficiencies caused by defects in respiratory complex subunits or assembly factors. Mitochondrion 2015; 21:76-91. [PMID: 25660179 DOI: 10.1016/j.mito.2015.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/22/2014] [Accepted: 01/05/2015] [Indexed: 10/24/2022]
Abstract
Mitochondrial disorders are the most common inborn errors of metabolism affecting the oxidative phosphorylation system (OXPHOS). Because of the poor knowledge of the pathogenic mechanisms, a cure for these disorders is still unavailable and all the treatments currently in use are supportive more than curative. Therefore, in the past decade a great variety of mouse models have been developed to assess the in vivo function of several mitochondrial proteins involved in human diseases. Due to the genetic and physiological similarity to humans, mice represent reliable models to study the pathogenic mechanisms of mitochondrial disorders and are precious to test new therapeutic approaches. Here we summarize the features of several mouse models of mitochondrial diseases directly related to defects in subunits of the OXPHOS complexes or in assembly factors. We discuss how these models recapitulate many human conditions and how they have contributed to the understanding of mitochondrial function in health and disease.
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Affiliation(s)
- Alessandra Torraco
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Viale di San Paolo, 15-00146 Rome, Italy.
| | - Susana Peralta
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
| | - Francisca Diaz
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
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22
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Martelli A, Schmucker S, Reutenauer L, Mathieu JRR, Peyssonnaux C, Karim Z, Puy H, Galy B, Hentze MW, Puccio H. Iron regulatory protein 1 sustains mitochondrial iron loading and function in frataxin deficiency. Cell Metab 2015; 21:311-323. [PMID: 25651183 DOI: 10.1016/j.cmet.2015.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 12/22/2014] [Accepted: 01/16/2015] [Indexed: 12/22/2022]
Abstract
Mitochondrial iron accumulation is a hallmark of diseases associated with impaired iron-sulfur cluster (Fe-S) biogenesis, such as Friedreich ataxia linked to frataxin (FXN) deficiency. The pathophysiological relevance of the mitochondrial iron loading and the underlying mechanisms are unknown. Using a mouse model of hepatic FXN deficiency in combination with mice deficient for iron regulatory protein 1 (IRP1), a key regulator of cellular iron metabolism, we show that IRP1 activation in conditions of Fe-S deficiency increases the available cytosolic labile iron pool. Surprisingly, our data indicate that IRP1 activation sustains mitochondrial iron supply and function rather than driving detrimental iron overload. Mitochondrial iron accumulation is shown to depend on mitochondrial dysfunction and heme-dependent upregulation of the mitochondrial iron importer mitoferrin-2. Our results uncover an unexpected protective role of IRP1 in pathological conditions associated with altered Fe-S metabolism.
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Affiliation(s)
- Alain Martelli
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France.
| | - Stéphane Schmucker
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France
| | - Laurence Reutenauer
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France
| | - Jacques R R Mathieu
- Institut Cochin, INSERM, U1016, CNRS, UMR8104, Université Paris Descartes, 75014 Paris, France
| | - Carole Peyssonnaux
- Institut Cochin, INSERM, U1016, CNRS, UMR8104, Université Paris Descartes, 75014 Paris, France
| | - Zoubida Karim
- Inserm Unité 1149, Center for Research on Inflammation (CRI), Université Paris Diderot, Sorbonne Paris Cité, site Bichat, 75018 Paris, France
| | - Hervé Puy
- Inserm Unité 1149, Center for Research on Inflammation (CRI), Université Paris Diderot, Sorbonne Paris Cité, site Bichat, 75018 Paris, France; AP-HP, Centre Français des Porphyries, Hôpital Louis Mourier, 92701 Colombes, France
| | - Bruno Galy
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | - Hélène Puccio
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France.
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23
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Generating Mouse Models of Mitochondrial Disease. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00043-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] Open
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24
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Davoudi M, Kallijärvi J, Marjavaara S, Kotarsky H, Hansson E, Levéen P, Fellman V. A mouse model of mitochondrial complex III dysfunction induced by myxothiazol. Biochem Biophys Res Commun 2014; 446:1079-84. [PMID: 24661880 DOI: 10.1016/j.bbrc.2014.03.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 03/15/2014] [Indexed: 11/17/2022]
Abstract
Myxothiazol is a respiratory chain complex III (CIII) inhibitor that binds to the ubiquinol oxidation site Qo of CIII. It blocks electron transfer from ubiquinol to cytochrome b and thus inhibits CIII activity. It has been utilized as a tool in studies of respiratory chain function in in vitro and cell culture models. We developed a mouse model of biochemically induced and reversible CIII inhibition using myxothiazol. We administered myxothiazol intraperitoneally at a dose of 0.56 mg/kg to C57Bl/J6 mice every 24 h and assessed CIII activity, histology, lipid content, supercomplex formation, and gene expression in the livers of the mice. A reversible CIII activity decrease to 50% of control value occurred at 2 h post-injection. At 74 h only minor histological changes in the liver were found, supercomplex formation was preserved and no significant changes in the expression of genes indicating hepatotoxicity or inflammation were found. Thus, myxothiazol-induced CIII inhibition can be induced in mice for four days in a row without overt hepatotoxicity or lethality. This model could be utilized in further studies of respiratory chain function and pharmacological approaches to mitochondrial hepatopathies.
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Affiliation(s)
- Mina Davoudi
- Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185, Sweden
| | - Jukka Kallijärvi
- Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014, Finland
| | - Sanna Marjavaara
- Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014, Finland
| | - Heike Kotarsky
- Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185, Sweden
| | - Eva Hansson
- Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185, Sweden
| | - Per Levéen
- Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185, Sweden; Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014, Finland
| | - Vineta Fellman
- Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185, Sweden; Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014, Finland; Children's Hospital, Helsinki University Hospital, University of Helsinki, Helsinki 00029, Finland.
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25
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Martelli A, Friedman LS, Reutenauer L, Messaddeq N, Perlman SL, Lynch DR, Fedosov K, Schulz JB, Pandolfo M, Puccio H. Clinical data and characterization of the liver conditional mouse model exclude neoplasia as a non-neurological manifestation associated with Friedreich's ataxia. Dis Model Mech 2012; 5:860-9. [PMID: 22736457 PMCID: PMC3484868 DOI: 10.1242/dmm.009829] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 06/06/2012] [Indexed: 01/01/2023] Open
Abstract
Friedreich's ataxia (FRDA) is the most common hereditary ataxia in the caucasian population and is characterized by a mixed spinocerebellar and sensory ataxia, hypertrophic cardiomyopathy and increased incidence of diabetes. FRDA is caused by impaired expression of the FXN gene coding for the mitochondrial protein frataxin. During the past ten years, the development of mouse models of FRDA has allowed better understanding of the pathophysiology of the disease. Among the mouse models of FRDA, the liver conditional mouse model pointed to a tumor suppressor activity of frataxin leading to the hypothesis that individuals with FRDA might be predisposed to cancer. In the present work, we investigated the presence and the incidence of neoplasia in the largest FRDA patient cohorts from the USA, Australia and Europe. As no predisposition to cancer could be observed in both cohorts, we revisited the phenotype of the liver conditional mouse model. Our results show that frataxin-deficient livers developed early mitochondriopathy, iron-sulfur cluster deficits and intramitochondrial dense deposits, classical hallmarks observed in frataxin-deficient tissues and cells. With age, a minority of mice developed structures similar to the ones previously associated with tumor formation. However, these peripheral structures contained dying, frataxin-deficient hepatocytes, whereas the inner liver structure was composed of a pool of frataxin-positive cells, due to inefficient Cre-mediated recombination of the Fxn gene, that contributed to regeneration of a functional liver. Together, our data demonstrate that frataxin deficiency and tumorigenesis are not associated.
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Affiliation(s)
- Alain Martelli
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France
- INSERM, U596, 67404 Illkirch, France
- CNRS, UMR7104, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
- Collège de France, Chaire de génétique humaine, 67404 Illkirch, France
| | - Lisa S. Friedman
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Laurence Reutenauer
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France
- INSERM, U596, 67404 Illkirch, France
- CNRS, UMR7104, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
- Collège de France, Chaire de génétique humaine, 67404 Illkirch, France
| | - Nadia Messaddeq
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France
- INSERM, U596, 67404 Illkirch, France
- CNRS, UMR7104, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
- Collège de France, Chaire de génétique humaine, 67404 Illkirch, France
| | - Susan L. Perlman
- University of California Los Angeles (UCLA), Los Angeles, CA 90095, USA
| | - David R. Lynch
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Kathrin Fedosov
- Department of Neurology, University Hospital Aachen, 52074 Aachen, Germany
| | - Jörg B. Schulz
- Department of Neurology, University Hospital Aachen, 52074 Aachen, Germany
| | - Massimo Pandolfo
- Laboratoire de Neurologie Expérimentale, Hôpital Erasme, Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Hélène Puccio
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch, France
- INSERM, U596, 67404 Illkirch, France
- CNRS, UMR7104, 67404 Illkirch, France
- Université de Strasbourg, 67404 Illkirch, France
- Collège de France, Chaire de génétique humaine, 67404 Illkirch, France
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26
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Fünfschilling U, Supplie LM, Mahad D, Boretius S, Saab AS, Edgar J, Brinkmann BG, Kassmann CM, Tzvetanova ID, Möbius W, Diaz F, Meijer D, Suter U, Hamprecht B, Sereda MW, Moraes CT, Frahm J, Goebbels S, Nave KA. Glycolytic oligodendrocytes maintain myelin and long-term axonal integrity. Nature 2012; 485:517-21. [PMID: 22622581 DOI: 10.1038/nature11007] [Citation(s) in RCA: 976] [Impact Index Per Article: 81.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 03/02/2012] [Indexed: 11/09/2022]
Abstract
Oligodendrocytes, the myelin-forming glial cells of the central nervous system, maintain long-term axonal integrity. However, the underlying support mechanisms are not understood. Here we identify a metabolic component of axon-glia interactions by generating conditional Cox10 (protoheme IX farnesyltransferase) mutant mice, in which oligodendrocytes and Schwann cells fail to assemble stable mitochondrial cytochrome c oxidase (COX, also known as mitochondrial complex IV). In the peripheral nervous system, Cox10 conditional mutants exhibit severe neuropathy with dysmyelination, abnormal Remak bundles, muscle atrophy and paralysis. Notably, perturbing mitochondrial respiration did not cause glial cell death. In the adult central nervous system, we found no signs of demyelination, axonal degeneration or secondary inflammation. Unlike cultured oligodendrocytes, which are sensitive to COX inhibitors, post-myelination oligodendrocytes survive well in the absence of COX activity. More importantly, by in vivo magnetic resonance spectroscopy, brain lactate concentrations in mutants were increased compared with controls, but were detectable only in mice exposed to volatile anaesthetics. This indicates that aerobic glycolysis products derived from oligodendrocytes are rapidly metabolized within white matter tracts. Because myelinated axons can use lactate when energy-deprived, our findings suggest a model in which axon-glia metabolic coupling serves a physiological function.
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Affiliation(s)
- Ursula Fünfschilling
- Max Planck Institute of Experimental Medicine, Department of Neurogenetics, Hermann-Rein-Strasse 3, D-37075 Göttingen, Germany
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27
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Martelli A, Napierala M, Puccio H. Understanding the genetic and molecular pathogenesis of Friedreich's ataxia through animal and cellular models. Dis Model Mech 2012; 5:165-76. [PMID: 22382366 PMCID: PMC3291638 DOI: 10.1242/dmm.008706] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In 1996, a link was identified between Friedreich's ataxia (FRDA), the most common inherited ataxia in men, and alterations in the gene encoding frataxin (FXN). Initial studies revealed that the disease is caused by a unique, most frequently biallelic, expansion of the GAA sequence in intron 1 of FXN. Since the identification of this link, there has been tremendous progress in understanding frataxin function and the mechanism of FRDA pathology, as well as in developing diagnostics and therapeutic approaches for the disease. These advances were the subject of the 4th International Friedreich's Ataxia Conference held on 5th-7th May in the Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France. More than 200 scientists gathered from all over the world to present the results of research spanning all areas of investigation into FRDA (including clinical aspects, FRDA pathogenesis, genetics and epigenetics of the disease, development of new models of FRDA, and drug discovery). This review provides an update on the understanding of frataxin function, developments of animal and cellular models of the disease, and recent advances in trying to uncover potential molecules for therapy.
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Affiliation(s)
- Alain Martelli
- Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), 67404, Illkirch, France
- Inserm, U596, 67400, Illkirch, France
- CNRS, UMR7104, 67400, Illkirch, France
- Université de Strasbourg, 67000, Strasbourg, France
- Collège de France, Chaire de génétique humaine, 67400, Illkirch, France
| | - Marek Napierala
- The Department of Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center Science Park, Smithville, TX, USA
| | - Hélène Puccio
- Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), 67404, Illkirch, France
- Inserm, U596, 67400, Illkirch, France
- CNRS, UMR7104, 67400, Illkirch, France
- Université de Strasbourg, 67000, Strasbourg, France
- Collège de France, Chaire de génétique humaine, 67400, Illkirch, France
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28
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Cells lacking Rieske iron-sulfur protein have a reactive oxygen species-associated decrease in respiratory complexes I and IV. Mol Cell Biol 2011; 32:415-29. [PMID: 22106410 DOI: 10.1128/mcb.06051-11] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Mitochondrial respiratory complexes of the electron transport chain (CI, CIII, and CIV) can be assembled into larger structures forming supercomplexes. We analyzed the assembly/stability of respiratory complexes in mouse lung fibroblasts lacking the Rieske iron-sulfur protein (RISP knockout [KO]cells), one of the catalytic subunits of CIII. In the absence of RISP, most of the remaining CIII subunits were able to assemble into a large precomplex that lacked enzymatic activity. CI, CIV, and supercomplexes were decreased in the RISP-deficient cells. Reintroduction of RISP into KO cells restored CIII activity and increased the levels of active CI, CIV, and supercomplexes. We found that hypoxia (1% O(2)) resulted in increased levels of CI, CIV, and supercomplex assembly in RISP KO cells. In addition, treatment of control cells with different oxidative phosphorylation (OXPHOS) inhibitors showed that compounds known to generate reactive oxygen species (ROS) (e.g., antimycin A and oligomycin) had a negative impact on CI and supercomplex levels. Accordingly, a superoxide dismutase (SOD) mimetic compound and SOD2 overexpression provided a partial increase in supercomplex levels in the RISP KO cells. Our data suggest that the stability of CI, CIV, and supercomplexes is regulated by ROS in the context of defective oxidative phosphorylation.
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Levéen P, Kotarsky H, Mörgelin M, Karikoski R, Elmér E, Fellman V. The GRACILE mutation introduced into Bcs1l causes postnatal complex III deficiency: a viable mouse model for mitochondrial hepatopathy. Hepatology 2011; 53:437-47. [PMID: 21274865 DOI: 10.1002/hep.24031] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 09/24/2010] [Indexed: 12/07/2022]
Abstract
UNLABELLED Mitochondrial dysfunction is an important cause for neonatal liver disease. Disruption of genes encoding oxidative phosphorylation (OXPHOS) components usually causes embryonic lethality, and thus few disease models are available. We developed a mouse model for GRACILE syndrome, a neonatal mitochondrial disease with liver and kidney involvement, caused by a homozygous BCS1L mutation (232A>G). This gene encodes a chaperone required for incorporation of Rieske iron-sulfur protein (RISP) into complex III of respiratory chain. Homozygous mutant mice after 3 weeks of age developed striking similarities to the human disease: growth failure, hepatic glycogen depletion, steatosis, fibrosis, and cirrhosis, as well as tubulopathy, complex III deficiency, lactacidosis, and short lifespan. BCS1L was decreased in whole liver cells and isolated mitochondria of mutants at all ages. RISP incorporation into complex III was diminished in symptomatic animals; however, in young animals complex III was correctly assembled. Complex III activity in liver, heart, and kidney of symptomatic mutants was decreased to 20%, 40%, and 40% of controls, respectively, as demonstrated with electron flux kinetics through complex III. In high-resolution respirometry, CIII dysfunction resulted in decreased electron transport capacity through the respiratory chain under maximum substrate input. Complex I function, suggested to be dependent on a functional complex III, was, however, unaffected. CONCLUSION We present the first viable model of complex III deficiency mimicking a human mitochondrial disorder. Incorporation of RISP into complex III in young homozygotes suggests another complex III assembly factor during early ontogenesis. The development of symptoms from about 3 weeks of age provides a convenient time window for studying the pathophysiology and treatment of mitochondrial hepatopathy and OXPHOS dysfunction in general.
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Affiliation(s)
- Per Levéen
- Department of Pediatrics, Clinical Sciences, Lund University, Lund, Sweden
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Wang G, Chen HW, Oktay Y, Zhang J, Allen EL, Smith GM, Fan KC, Hong JS, French SW, McCaffery JM, Lightowlers RN, Morse HC, Koehler CM, Teitell MA. PNPASE regulates RNA import into mitochondria. Cell 2010; 142:456-67. [PMID: 20691904 DOI: 10.1016/j.cell.2010.06.035] [Citation(s) in RCA: 260] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 03/20/2010] [Accepted: 05/13/2010] [Indexed: 02/04/2023]
Abstract
RNA import into mammalian mitochondria is considered essential for replication, transcription, and translation of the mitochondrial genome but the pathway(s) and factors that control this import are poorly understood. Previously, we localized polynucleotide phosphorylase (PNPASE), a 3' --> 5' exoribonuclease and poly-A polymerase, in the mitochondrial intermembrane space, a location lacking resident RNAs. Here, we show a new role for PNPASE in regulating the import of nuclear-encoded RNAs into the mitochondrial matrix. PNPASE reduction impaired mitochondrial RNA processing and polycistronic transcripts accumulated. Augmented import of RNase P, 5S rRNA, and MRP RNAs depended on PNPASE expression and PNPASE-imported RNA interactions were identified. PNPASE RNA processing and import activities were separable and a mitochondrial RNA targeting signal was isolated that enabled RNA import in a PNPASE-dependent manner. Combined, these data strongly support an unanticipated role for PNPASE in mediating the translocation of RNAs into mitochondria.
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Affiliation(s)
- Geng Wang
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
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Diaz F. Cytochrome c oxidase deficiency: patients and animal models. Biochim Biophys Acta Mol Basis Dis 2009; 1802:100-10. [PMID: 19682572 DOI: 10.1016/j.bbadis.2009.07.013] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 07/30/2009] [Accepted: 07/31/2009] [Indexed: 12/17/2022]
Abstract
Cytochrome c oxidase (COX) deficiencies are one of the most common defects of the respiratory chain found in mitochondrial diseases. COX is a multimeric inner mitochondrial membrane enzyme formed by subunits encoded by both the nuclear and the mitochondrial genome. COX biosynthesis requires numerous assembly factors that do not form part of the final complex but participate in prosthetic group synthesis and metal delivery in addition to membrane insertion and maturation of COX subunits. Human diseases associated with COX deficiency including encephalomyopathies, Leigh syndrome, hypertrophic cardiomyopathies, and fatal lactic acidosis are caused by mutations in COX subunits or assembly factors. In the last decade, numerous animal models have been created to understand the pathophysiology of COX deficiencies and the function of assembly factors. These animal models, ranging from invertebrates to mammals, in most cases mimic the pathological features of the human diseases.
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Affiliation(s)
- Francisca Diaz
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, Florida 33136, USA.
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Abstract
It is now clear that mitochondrial defects are associated with a plethora of clinical phenotypes in man and mouse. This is the result of the mitochondria's central role in energy production, reactive oxygen species (ROS) biology, and apoptosis, and because the mitochondrial genome consists of roughly 1500 genes distributed across the maternal mitochondrial DNA (mtDNA) and the Mendelian nuclear DNA (nDNA). While numerous pathogenic mutations in both mtDNA and nDNA mitochondrial genes have been identified in the past 21 years, the causal role of mitochondrial dysfunction in the common metabolic and degenerative diseases, cancer, and aging is still debated. However, the development of mice harboring mitochondrial gene mutations is permitting demonstration of the direct cause-and-effect relationship between mitochondrial dysfunction and disease. Mutations in nDNA-encoded mitochondrial genes involved in energy metabolism, antioxidant defenses, apoptosis via the mitochondrial permeability transition pore (mtPTP), mitochondrial fusion, and mtDNA biogenesis have already demonstrated the phenotypic importance of mitochondrial defects. These studies are being expanded by the recent development of procedures for introducing mtDNA mutations into the mouse. These studies are providing direct proof that mtDNA mutations are sufficient by themselves to generate major clinical phenotypes. As more different mtDNA types and mtDNA gene mutations are introduced into various mouse nDNA backgrounds, the potential functional role of mtDNA variation in permitting humans and mammals to adapt to different environments and in determining their predisposition to a wide array of diseases should be definitively demonstrated.
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Affiliation(s)
- Douglas C Wallace
- Organizational Research Unit for Molecular and Mitochondrial Medicine and Genetics, University of California at Irvine, Irvine, California 92697, USA.
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Fellous TG, Islam S, Tadrous PJ, Elia G, Kocher HM, Bhattacharya S, Mears L, Turnbull DM, Taylor RW, Greaves LC, Chinnery PF, Taylor G, McDonald SAC, Wright NA, Alison MR. Locating the stem cell niche and tracing hepatocyte lineages in human liver. Hepatology 2009; 49:1655-63. [PMID: 19309719 DOI: 10.1002/hep.22791] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UNLABELLED We have used immunohistochemical and histochemical techniques to identify patches of hepatocytes deficient in the enzyme cytochrome c oxidase, a component of the electron transport chain and encoded by mitochondrial DNA (mtDNA). These patches invariably abutted the portal tracts and expanded laterally as they spread toward the hepatic veins. Here we investigate, using mtDNA mutations as a marker of clonal expansion, the clonality of these patches. Negative hepatocytes were laser-capture microdissected and mutations identified by polymerase chain reaction sequencing of the entire mtDNA genome. Patches of cytochrome c oxidase-deficient hepatocytes were clonal, suggesting an origin from a long-lived cell, presumably a stem cell. Immunohistochemical analysis of function and proliferation suggested that these mutations in cytochrome c oxidase-deficient hepatocytes were nonpathogenic. CONCLUSION These data show, for the first time, that clonal proliferative units exist in the human liver, an origin from a periportal niche is most likely, and that the trajectory of the units is compatible with a migration of cells from the periportal regions to the hepatic veins.
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Affiliation(s)
- Tariq G Fellous
- Centre for Diabetes and Metabolic Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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Torraco A, Diaz F, Vempati UD, Moraes CT. Mouse models of oxidative phosphorylation defects: powerful tools to study the pathobiology of mitochondrial diseases. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1793:171-80. [PMID: 18601959 PMCID: PMC2652735 DOI: 10.1016/j.bbamcr.2008.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/28/2008] [Accepted: 06/04/2008] [Indexed: 01/14/2023]
Abstract
Defects in the oxidative phosphorylation system (OXPHOS) are responsible for a group of extremely heterogeneous and pleiotropic pathologies commonly known as mitochondrial diseases. Although many mutations have been found to be responsible for OXPHOS defects, their pathogenetic mechanisms are still poorly understood. An important contribution to investigate the in vivo function of several mitochondrial proteins and their role in mitochondrial dysfunction, has been provided by mouse models. Thanks to their genetic and physiologic similarity to humans, mouse models represent a powerful tool to investigate the impact of pathological mutations on metabolic pathways. In this review we discuss the main mouse models of mitochondrial disease developed, focusing on the ones that directly affect the OXPHOS system.
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Affiliation(s)
- Alessandra Torraco
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Francisca Diaz
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Uma D. Vempati
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Carlos T. Moraes
- Department of Neurology, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
- Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA
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Vempati UD, Torraco A, Moraes CT. Mouse models of oxidative phosphorylation dysfunction and disease. Methods 2008; 46:241-7. [PMID: 18848991 PMCID: PMC2652743 DOI: 10.1016/j.ymeth.2008.09.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 08/28/2008] [Accepted: 09/12/2008] [Indexed: 11/23/2022] Open
Abstract
Oxidative phosphorylation (OXPHOS) deficiency results in a number of human diseases, affecting at least one in 5000 of the general population. Altering the function of genes by mutations are central to our understanding their function. Prior to the development of gene targeting, this approach was limited to rare spontaneous mutations that resulted in a phenotype. Since its discovery, targeted mutagenesis of the mouse germline has proved to be a powerful approach to understand the in vivo function of genes. Gene targeting has yielded remarkable understanding of the role of several gene products in the OXPHOS system. We provide a "tool box" of mouse models with OXPHOS defects that could be used to answer diverse scientific questions.
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Affiliation(s)
| | | | - Carlos T. Moraes
- Department of Neurology, University of Miami, USA
- Department of Cell Biology & Anatomy, University of Miami, USA
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Activation of the PPAR/PGC-1alpha pathway prevents a bioenergetic deficit and effectively improves a mitochondrial myopathy phenotype. Cell Metab 2008; 8:249-56. [PMID: 18762025 PMCID: PMC2613643 DOI: 10.1016/j.cmet.2008.07.006] [Citation(s) in RCA: 262] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 06/24/2008] [Accepted: 07/23/2008] [Indexed: 02/06/2023]
Abstract
Neuromuscular disorders with defects in the mitochondrial ATP-generating system affect a large number of children and adults worldwide, but remain without treatment. We used a mouse model of mitochondrial myopathy, caused by a cytochrome c oxidase deficiency, to evaluate the effect of induced mitochondrial biogenesis on the course of the disease. Mitochondrial biogenesis was induced either by transgenic expression of peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator alpha (PGC-1alpha) in skeletal muscle or by administration of bezafibrate, a PPAR panagonist. Both strategies successfully stimulated residual respiratory capacity in muscle tissue. Mitochondrial proliferation resulted in an enhanced OXPHOS capacity per muscle mass. As a consequence, ATP levels were conserved resulting in a delayed onset of the myopathy and a markedly prolonged life span. Thus, induction of mitochondrial biogenesis through pharmacological or metabolic modulation of the PPAR/PGC-1alpha pathway promises to be an effective therapeutic approach for mitochondrial disorders.
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Diaz F, Moraes CT. Mitochondrial biogenesis and turnover. Cell Calcium 2008; 44:24-35. [PMID: 18395251 DOI: 10.1016/j.ceca.2007.12.004] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2007] [Revised: 12/10/2007] [Accepted: 12/12/2007] [Indexed: 11/17/2022]
Abstract
Mitochondrial biogenesis is a complex process involving the coordinated expression of mitochondrial and nuclear genes, the import of the products of the latter into the organelle and turnover. The mechanisms associated with these events have been intensively studied in the last 20 years and our understanding of their details is much improved. Mitochondrial biogenesis requires the participation of calcium signaling that activates a series of calcium-dependent protein kinases that in turn activate transcription factors and coactivators such as PGC-1alpha that regulates the expression of genes coding for mitochondrial components. In addition, mitochondrial biogenesis involves the balance of mitochondrial fission-fusion. Mitochondrial malfunction or defects in any of the many pathways involved in mitochondrial biogenesis can lead to degenerative diseases and possibly play an important part in aging.
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Affiliation(s)
- Francisca Diaz
- Department of Neurology, University of Miami, Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA.
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