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Du Z, Zhou X, Lai Y, Xu J, Zhang Y, Zhou S, Feng Z, Yu L, Tang Y, Wang W, Yu L, Tian C, Ran T, Chen H, Guddat LW, Liu F, Gao Y, Rao Z, Gong H. Structure of the human respiratory complex II. Proc Natl Acad Sci U S A 2023; 120:e2216713120. [PMID: 37098072 PMCID: PMC10161127 DOI: 10.1073/pnas.2216713120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/10/2023] [Indexed: 04/26/2023] Open
Abstract
Human complex II is a key protein complex that links two essential energy-producing processes: the tricarboxylic acid cycle and oxidative phosphorylation. Deficiencies due to mutagenesis have been shown to cause mitochondrial disease and some types of cancers. However, the structure of this complex is yet to be resolved, hindering a comprehensive understanding of the functional aspects of this molecular machine. Here, we have determined the structure of human complex II in the presence of ubiquinone at 2.86 Å resolution by cryoelectron microscopy, showing it comprises two water-soluble subunits, SDHA and SDHB, and two membrane-spanning subunits, SDHC and SDHD. This structure allows us to propose a route for electron transfer. In addition, clinically relevant mutations are mapped onto the structure. This mapping provides a molecular understanding to explain why these variants have the potential to produce disease.
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Affiliation(s)
- Zhanqiang Du
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Xiaoting Zhou
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China
| | - Yuezheng Lai
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Jinxu Xu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Yuying Zhang
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Shan Zhou
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Ziyan Feng
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Long Yu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Yanting Tang
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Weiwei Wang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Lu Yu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Changlin Tian
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Ting Ran
- Innovative Center For Pathogen Research, Guangzhou Laboratory, Guangzhou 510005, China
| | - Hongming Chen
- Innovative Center For Pathogen Research, Guangzhou Laboratory, Guangzhou 510005, China
| | - Luke W Guddat
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Fengjiang Liu
- Innovative Center For Pathogen Research, Guangzhou Laboratory, Guangzhou 510005, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zihe Rao
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China
| | - Hongri Gong
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
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2
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Zhu L, Liu H, Dou Y, Luo Q, Gu L, Liu X, Zhou Q, Han J, Wang F. A Photoactivated Ru (II) Polypyridine Complex Induced Oncotic Necrosis of A549 Cells by Activating Oxidative Phosphorylation and Inhibiting DNA Synthesis as Revealed by Quantitative Proteomics. Int J Mol Sci 2023; 24:ijms24097756. [PMID: 37175463 PMCID: PMC10178167 DOI: 10.3390/ijms24097756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023] Open
Abstract
The ruthenium polypyridine complex [Ru(dppa)2(pytp)] (PF6)2 (termed as ZQX-1), where dppa = 4,7-diphenyl-1,10-phenanthroline and pytp = 4'-pyrene-2,2':6',2''-terpyridine, has been shown a high and selective cytotoxicity to hypoxic and cisplatin-resistant cancer cells either under irradiation with blue light or upon two-photon excitation. The IC50 values of ZQX-1 towards A549 cancer cells and HEK293 health cells are 0.16 ± 0.09 µM and >100 µM under irradiation at 420 nm, respectively. However, the mechanism of action of ZQX-1 remains unclear. In this work, using the quantitative proteomics method we identified 84 differentially expressed proteins (DEPs) with |fold-change| ≥ 1.2 in A549 cancer cells exposed to ZQX-1 under irradiation at 420 nm. Bioinformatics analysis of the DEPs revealed that photoactivated ZQX-1 generated reactive oxygen species (ROS) to activate oxidative phosphorylation signaling to overproduce ATP; it also released ROS and pyrene derivative to damage DNA and arrest A549 cells at S-phase, which synergistically led to oncotic necrosis and apoptosis of A549 cells to deplete excess ATP, evidenced by the elevated level of PRAP1 and cleaved capase-3. Moreover, the DNA damage inhibited the expression of DNA repair-related proteins, such as RBX1 and GPS1, enhancing photocytotoxicity of ZQX-1, which was reflected in the inhibition of integrin signaling and disruption of ribosome assembly. Importantly, the photoactivated ZQX-1 was shown to activate hypoxia-inducible factor 1A (HIF1A) survival signaling, implying that combining use of ZQX-1 with HIF1A signaling inhibitors may further promote the photocytotoxicity of the prodrug.
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Affiliation(s)
- Li Zhu
- College of Applied Science and Technology, Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing 100101, China
| | - Hui Liu
- College of Applied Science and Technology, Beijing Key Laboratory of Bioactive Substances and Functional Foods, Beijing Union University, Beijing 100101, China
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yang Dou
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qun Luo
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liangzhen Gu
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xingkai Liu
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Qianxiong Zhou
- Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Juanjuan Han
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Fuyi Wang
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Centre for Excellence in Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250355, China
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Dona M, Lamers M, Rohde S, Gorissen M, Timmers HJLM. Targeting the Redox Balance Pathway Using Ascorbic Acid in sdhb Zebrafish Mutant Larvae. Cancers (Basel) 2021; 13:cancers13205124. [PMID: 34680273 PMCID: PMC8534273 DOI: 10.3390/cancers13205124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/06/2021] [Accepted: 10/11/2021] [Indexed: 12/15/2022] Open
Abstract
Simple Summary Thus far, no curative therapies are available for malignant SDHB-associated phaeochromocytomas and paragangliomas (PPGLs). Therapy development is severely hampered by the limited availability of suitable animal models. In this study, we investigated the potential of the sdhbrmc200 zebrafish model to study SDHB-associated PPGLs using a drug screening approach. One of the key features of cancer initiation and progression is redox imbalance. First, we identified increased reactive oxygen species levels in homozygous sdhbrmc200 larvae at baseline. Next, we tested the effect of anti- and pro-oxidant ascorbic acid (Vitamin C) on these larvae. We validated the sdhbrmc200 zebrafish model as a powerful drug screening tool to provide valuable insights into pathomechanisms, which may lead to novel therapeutic targets and therapy development in the future. Abstract Patients with mutations in the β-subunit of the succinate dehydrogenase (SDHB) have the highest risk to develop incurable malignant phaeochromocytomas and paragangliomas (PPGLs). Therapy development is hindered by limited possibilities to test new therapeutic strategies in vivo. One possible molecular mechanism of SDHB-associated tumorigenesis originates in an overproduction of reactive oxygen species (ROS) due to mitochondrial dysfunction. Ascorbic acid (Vitamin C) has already been shown to act as anti-cancer agent in several clinical trials for various types of cancer. In this study, the potential of the sdhbrmc200 zebrafish model to study SDHB-associated PPGLs using a drug screening approach was investigated. First, we identified increased basal ROS levels in homozygous sdhb larvae compared to heterozygous and wild-type siblings. Using a semi high-throughput drug screening, the effectiveness of different dosages of anti- and pro-oxidant Vitamin C were assessed to evaluate differences in survival, ROS levels, and locomotor activity. Low-dosage levels of Vitamin C induced a decrease of ROS levels but no significant effects on lifespan. In contrast, high-dosage levels of Vitamin C shortened the lifespan of the homozygous sdhbrmc200 larvae while not affecting the lifespan of heterozygous and wild-type siblings. These results validated the sdhbrmc200 zebrafish model as a powerful drug screening tool that may be used to identify novel therapeutic targets for SDHB-associated PPGLs.
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Affiliation(s)
- Margo Dona
- Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (M.L.); (S.R.); (H.J.L.M.T.)
- Correspondence:
| | - Maaike Lamers
- Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (M.L.); (S.R.); (H.J.L.M.T.)
| | - Svenja Rohde
- Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (M.L.); (S.R.); (H.J.L.M.T.)
| | - Marnix Gorissen
- Department of Animal Ecology and Physiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, 6525 AJ Nijmegen, The Netherlands;
| | - Henri J. L. M. Timmers
- Department of Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (M.L.); (S.R.); (H.J.L.M.T.)
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Consolidating biallelic SDHD variants as a cause of mitochondrial complex II deficiency. Eur J Hum Genet 2021; 29:1570-1576. [PMID: 34012134 PMCID: PMC8484551 DOI: 10.1038/s41431-021-00887-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 02/18/2021] [Accepted: 03/30/2021] [Indexed: 02/07/2023] Open
Abstract
Isolated mitochondrial complex II deficiency is a rare cause of mitochondrial respiratory chain disease. To date biallelic variants in three genes encoding mitochondrial complex II molecular components have been unequivocally associated with mitochondrial disease (SDHA/SDHB/SDHAF1). Additionally, variants in one further complex II component (SDHD) have been identified as a candidate cause of isolated mitochondrial complex II deficiency in just two unrelated affected individuals with clinical features consistent with mitochondrial disease, including progressive encephalomyopathy and lethal infantile cardiomyopathy. We present clinical and genomic investigations in four individuals from an extended Palestinian family with clinical features consistent with an autosomal recessive mitochondrial complex II deficiency, in which our genomic studies identified a homozygous NM_003002.3:c.[205 G > A];[205 G > A];p.[(Glu69Lys)];[(Glu69Lys)] SDHD variant as the likely cause. Reviewing previously published cases, these findings consolidate disruption of SDHD function as a cause of mitochondrial complex II deficiency and further define the phenotypic spectrum associated with SDHD gene variants.
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5
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Dona M, Neijman K, Timmers HJLM. MITOCHONDRIA: Succinate dehydrogenase subunit B-associated phaeochromocytoma and paraganglioma. Int J Biochem Cell Biol 2021; 134:105949. [PMID: 33609747 DOI: 10.1016/j.biocel.2021.105949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 12/18/2022]
Abstract
Phaeochromocytomas and paragangliomas are rare neuroendocrine tumours. So far, over 20 causative genes have been identified, of which the most frequent and strongest indicator for malignancies are mutations in succinate dehydrogenase subunit B. No curative therapy is available for patients with metastases resulting in poor prognosis. Therapy development has been hindered by lack of suitable model systems. The succinate dehydrogenase complex is located in the inner membrane of the mitochondria and plays a crucial role in the oxidative phosphorylation chain and the tricarboxylic acid-cycle. Succinate dehydrogenase deficiency results in accumulation of the oncometabolite succinate inducing hypoxia inducible factor stabilization, deoxyribonucleic acid and histone methylation inhibition, and impaired production of adenosine triphosphate. It remains unknown which combination of pathways and/or triggers are decisive for metastases development. In this review, the role of mitochondria in malignant succinate dehydrogenase subunit B-associated phaeochromocytomas and paragangliomas and implications for mitochondria as therapeutic target are discussed.
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Affiliation(s)
- Margo Dona
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Kim Neijman
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Henri J L M Timmers
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.
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6
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Human Mitochondrial Pathologies of the Respiratory Chain and ATP Synthase: Contributions from Studies of Saccharomyces cerevisiae. Life (Basel) 2020; 10:life10110304. [PMID: 33238568 PMCID: PMC7700678 DOI: 10.3390/life10110304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022] Open
Abstract
The ease with which the unicellular yeast Saccharomyces cerevisiae can be manipulated genetically and biochemically has established this organism as a good model for the study of human mitochondrial diseases. The combined use of biochemical and molecular genetic tools has been instrumental in elucidating the functions of numerous yeast nuclear gene products with human homologs that affect a large number of metabolic and biological processes, including those housed in mitochondria. These include structural and catalytic subunits of enzymes and protein factors that impinge on the biogenesis of the respiratory chain. This article will review what is currently known about the genetics and clinical phenotypes of mitochondrial diseases of the respiratory chain and ATP synthase, with special emphasis on the contribution of information gained from pet mutants with mutations in nuclear genes that impair mitochondrial respiration. Our intent is to provide the yeast mitochondrial specialist with basic knowledge of human mitochondrial pathologies and the human specialist with information on how genes that directly and indirectly affect respiration were identified and characterized in yeast.
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7
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Fullerton M, McFarland R, Taylor RW, Alston CL. The genetic basis of isolated mitochondrial complex II deficiency. Mol Genet Metab 2020; 131:53-65. [PMID: 33162331 PMCID: PMC7758838 DOI: 10.1016/j.ymgme.2020.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 11/21/2022]
Abstract
Mitochondrial complex II (succinate:ubiquinone oxidoreductase) is the smallest complex of the oxidative phosphorylation system, a tetramer of just 140 kDa. Despite its diminutive size, it is a key complex in two coupled metabolic pathways - it oxidises succinate to fumarate in the tricarboxylic acid cycle and the electrons are used to reduce FAD to FADH2, ultimately reducing ubiquinone to ubiquinol in the respiratory chain. The biogenesis and assembly of complex II is facilitated by four ancillary proteins, all of which are autosomally-encoded. Numerous pathogenic defects have been reported which describe two broad clinical manifestations, either susceptibility to cancer in the case of single, heterozygous germline variants, or a mitochondrial disease presentation, almost exclusively due to bi-allelic recessive variants and associated with an isolated complex II deficiency. Here we present a compendium of pathogenic gene variants that have been documented in the literature in patients with an isolated mitochondrial complex II deficiency. To date, 61 patients are described, harbouring 32 different pathogenic variants in four distinct complex II genes: three structural subunit genes (SDHA, SDHB and SDHD) and one assembly factor gene (SDHAF1). Many pathogenic variants result in a null allele due to nonsense, frameshift or splicing defects however, the missense variants that do occur tend to induce substitutions at highly conserved residues in regions of the proteins that are critical for binding to other subunits or substrates. There is phenotypic heterogeneity associated with defects in each complex II gene, similar to other mitochondrial diseases.
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Affiliation(s)
- Millie Fullerton
- Wellcome Centre for Mitochondrial Research, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK; Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; NHS Highly Specialised Services for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK; Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; NHS Highly Specialised Services for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK
| | - Charlotte L Alston
- Wellcome Centre for Mitochondrial Research, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK; Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; NHS Highly Specialised Services for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK.
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Main AM, Rossing M, Borgwardt L, Grønkær Toft B, Rasmussen ÅK, Feldt-Rasmussen U. Genotype-phenotype associations in PPGLs in 59 patients with variants in SDHX genes. Endocr Connect 2020; 9:793-803. [PMID: 32688340 PMCID: PMC7487185 DOI: 10.1530/ec-20-0279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/19/2020] [Indexed: 12/31/2022]
Abstract
Phaeochromocytomas and paragangliomas (PPGLs) are tumours of the adrenal medulla and extra-adrenal sympathetic nervous system which often secrete catecholamines. Variants of the SDHX (SDHA, -AF2, -B, -C, -D) genes are a frequent cause of familial PPGLs. In this study from a single tertiary centre, we aimed to characterise the genotype-phenotype associations in patients diagnosed with germline variants in SDHX genes. We also assessed whether systematic screening of family members resulted in earlier detection of tumours. The study cohort comprised all individuals (n = 59) diagnosed with a rare variant in SDHX during a 13-year period. Patient- and pathology records were checked for clinical characteristics and histopathological findings. We found distinct differences in the clinical and histopathological characteristics between genetic variants in SDHB. We identified two SDHB variants with distinct phenotypical patterns. Family screening for SDHB variants resulted in earlier detection of tumours in two families. Patients with SDHA, SDHC and SDHD variants also had malignant phenotypes, underlining the necessity for a broad genetic screening of the proband. Our study corroborates previous findings of poor prognostic markers and found that the genetic variants and clinical phenotype are linked and, therefore, useful in the decision of clinical follow-up. Regular tumour screening of carriers of pathogenic variants may lead to an earlier diagnosis and expected better prognosis. The development of a combined algorithm with clinical, genetic, morphological, and biochemical factors may be the future for improved clinical risk stratification, forming a basis for larger multi-centre follow up studies.
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Affiliation(s)
- Ailsa Maria Main
- Department of Medical Endocrinology and Metabolism, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Correspondence should be addressed to A M Main or U Feldt-Rasmussen: or
| | - Maria Rossing
- Center for Genomic Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Line Borgwardt
- Center for Genomic Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Birgitte Grønkær Toft
- Department of Pathology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Åse Krogh Rasmussen
- Department of Medical Endocrinology and Metabolism, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Ulla Feldt-Rasmussen
- Department of Medical Endocrinology and Metabolism, Copenhagen University Hospital, Rigshospitalet, and Faculty of Health, Institute of Clinical and Scientific Research, Copenhagen, Denmark
- Correspondence should be addressed to A M Main or U Feldt-Rasmussen: or
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9
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Mukherjee S, Ghosh A. Molecular mechanism of mitochondrial respiratory chain assembly and its relation to mitochondrial diseases. Mitochondrion 2020; 53:1-20. [PMID: 32304865 DOI: 10.1016/j.mito.2020.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 03/28/2020] [Accepted: 04/07/2020] [Indexed: 12/17/2022]
Abstract
The mitochondrial respiratory chain (MRC) is comprised of ~92 nuclear and mitochondrial DNA-encoded protein subunits that are organized into five different multi-subunit respiratory complexes. These complexes produce 90% of the ATP required for cell sustenance. Specific sets of subunits are assembled in a modular or non-modular fashion to construct the MRC complexes. The complete assembly process is gradually chaperoned by a myriad of assembly factors that must coordinate with several other prosthetic groups to reach maturity, makingthe entire processextensively complicated. Further, the individual respiratory complexes can be integrated intovarious giant super-complexes whose functional roles have yet to be explored. Mutations in the MRC subunits and in the related assembly factors often give rise to defects in the proper assembly of the respiratory chain, which then manifests as a group of disorders called mitochondrial diseases, the most common inborn errors of metabolism. This review summarizes the current understanding of the biogenesis of individual MRC complexes and super-complexes, and explores how mutations in the different subunits and assembly factors contribute to mitochondrial disease pathology.
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Affiliation(s)
- Soumyajit Mukherjee
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India
| | - Alok Ghosh
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India.
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10
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Sciacovelli M, Schmidt C, Maher ER, Frezza C. Metabolic Drivers in Hereditary Cancer Syndromes. ANNUAL REVIEW OF CANCER BIOLOGY-SERIES 2020. [DOI: 10.1146/annurev-cancerbio-030419-033612] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cancer is a multifaceted disease in which inherited genetic variants can be important drivers of tumorigenesis. The discovery that germline mutations of metabolic genes predispose to familial forms of cancer caused a shift in our understanding of how metabolism contributes to tumorigenesis, providing evidence that metabolic alterations can be oncogenic. In this review, we focus on mitochondrial enzymes whose mutations predispose to familial cancer, and we fully appraise their involvement in cancer formation and progression. Elucidating the molecular mechanisms that orchestrate transformation in these diverse tumors may answer key biological questions about tumor formation and evolution, leading to the identification of new therapeutic targets of intervention.
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Affiliation(s)
- Marco Sciacovelli
- MRC (Medical Research Council) Cancer Unit, University of Cambridge, Cambridge CB2 0XZ, United Kingdom;,
| | - Christina Schmidt
- MRC (Medical Research Council) Cancer Unit, University of Cambridge, Cambridge CB2 0XZ, United Kingdom;,
| | - Eamonn R. Maher
- Department of Medical Genetics, NIHR (National Institute of Health Research) Cambridge Biomedical Research Centre, and Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Christian Frezza
- MRC (Medical Research Council) Cancer Unit, University of Cambridge, Cambridge CB2 0XZ, United Kingdom;,
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Kaur P, Sharma S, Kadavigere R, Girisha KM, Shukla A. Novel variant p.(Ala102Thr) in
SDHB
causes mitochondrial complex II deficiency: Case report and review of the literature. Ann Hum Genet 2020; 84:345-351. [DOI: 10.1111/ahg.12377] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/26/2019] [Accepted: 01/08/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Parneet Kaur
- Department of Medical Genetics Kasturba Medical College, Manipal Manipal Academy of Higher Education Manipal India
| | - Suvasini Sharma
- Neurology Division Department of Pediatrics Lady Hardinge Medical College and Associated Kalawati Saran Children's Hospital New Delhi India
| | - Rajagopal Kadavigere
- Department of Radiodiagnosis & Imaging Kasturba Medical College, Manipal Manipal Academy of Higher Education Manipal India
| | - Katta Mohan Girisha
- Department of Medical Genetics Kasturba Medical College, Manipal Manipal Academy of Higher Education Manipal India
| | - Anju Shukla
- Department of Medical Genetics Kasturba Medical College, Manipal Manipal Academy of Higher Education Manipal India
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12
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Karimzadeh P, Keramatipour M, Karamzade A, Pourbakhtyaran E. Succinate Dehydrogenase Deficiency: A Treatable Neurometabolic Disorder. IRANIAN JOURNAL OF CHILD NEUROLOGY 2020; 14:111-116. [PMID: 33193791 PMCID: PMC7660022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/18/2020] [Indexed: 11/02/2022]
Abstract
Succinate dehydrogenase (SDH) deficiency is a rare autosomal recessive neurometabolic disorder that causes brain insult, neurodevelopmental delay, exercise intolerance, and cardiomyopathy. A 25-month-old boy was referred to our neurometabolic center due to developmental regression after injecting the influenza vaccine when he was 10 months old. Magnetic resonance imaging (MRI) showed high signal changes in the brain white matter, and magnetic resonance spectroscopy (MRS) detected a high succinate peak at 2.4 parts per million (ppm). The evaluation of urine organic acids showed a significant elevated succinic acid and whole exome sequencing, confirming SDH. Treatment with a mitochondrial cocktail was initiated, and remarkable improvement was observed. SDH deficiency as a treatable neurometabolic disorder should be considered in any patients with developmental disorders, accompanied by hyperintensity in white matter (as similar to leukodystrophia). Further evaluation is recommended since outcomes depend on early diagnosis and treatment.
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Affiliation(s)
- Parvaneh Karimzadeh
- Pediatric Neurology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Pediatric Neurology Department, Mofid Children's Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Keramatipour
- Department of Medical Genetics, School of Medicine, Tehran, Iran University of Medical Sciences, Tehran, Iran
| | - Arezou Karamzade
- PhD candidate, Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Elham Pourbakhtyaran
- Pediatric Neurology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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