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Cao K, Xu J, Cao W, Wang X, Lv W, Zeng M, Zou X, Liu J, Feng Z. Assembly of mitochondrial succinate dehydrogenase in human health and disease. Free Radic Biol Med 2023; 207:247-259. [PMID: 37490987 DOI: 10.1016/j.freeradbiomed.2023.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 07/27/2023]
Abstract
Mitochondrial succinate dehydrogenase (SDH), also known as electron transport chain (ETC) Complex II, is the only enzyme complex engaged in both oxidative phosphorylation and the tricarboxylic acid (TCA) cycle. SDH has received increasing attention due to its crucial role in regulating mitochondrial metabolism and human health. Despite having the fewest subunits among the four ETC complexes, functional SDH is formed via a sequential and well-coordinated assembly of subunits. Along with the discovery of subunit-specific assembly factors, the dynamic involvement of the SDH assembly process in a broad range of diseases has been revealed. Recently, we reported that perturbation of SDH assembly in different tissues leads to interesting and distinct pathophysiological changes in mice, indicating a need to understand the intricate SDH assembly process in human health and diseases. Thus, in this review, we summarize recent findings on SDH pathogenesis with respect to disease and a focus on SDH assembly.
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Affiliation(s)
- Ke Cao
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China; Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jie Xu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Wenli Cao
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Xueqiang Wang
- School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, Shandong, 266071, China
| | - Weiqiang Lv
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China
| | - Mengqi Zeng
- School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, Shandong, 266071, China
| | - Xuan Zou
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, China
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, China; School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, Shandong, 266071, China.
| | - Zhihui Feng
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China; School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, Shandong, 266071, China.
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Bayley JP, Devilee P. Hypothesis: Why Different Types of SDH Gene Variants Cause Divergent Tumor Phenotypes. Genes (Basel) 2022; 13:genes13061025. [PMID: 35741787 PMCID: PMC9222429 DOI: 10.3390/genes13061025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/01/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022] Open
Abstract
Despite two decades of paraganglioma-pheochromocytoma research, the fundamental question of how the different succinate dehydrogenase (SDH)-related tumor phenotypes are initiated has remained unanswered. Here, we discuss two possible scenarios by which missense (hypomorphic alleles) or truncating (null alleles) SDH gene variants determine clinical phenotype. Dysfunctional SDH is a major source of reactive oxygen species (ROS) but ROS are inhibited by rising succinate levels. In scenario 1, we propose that SDH missense variants disrupt electron flow, causing elevated ROS levels that are toxic in sympathetic PPGL precursor cells but well controlled in oxygen-sensing parasympathetic paraganglion cells. We also suggest that SDHAF2 variants, solely associated with HNPGL, may cause the reversal of succinate dehydrogenase to fumarate reductase, producing very high ROS levels. In scenario 2, we propose a modified succinate threshold model of tumor initiation. Truncating SDH variants cause high succinate accumulation and likely initiate tumorigenesis via disruption of 2-oxoglutarate-dependent enzymes in both PPGL and HNPGL precursor tissues. We propose that missense variants (including SDHAF2) cause lower succinate accumulation and thus initiate tumorigenesis only in very metabolically active tissues such as parasympathetic paraganglia, which naturally show very high levels of succinate.
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Affiliation(s)
- Jean-Pierre Bayley
- Department of Human Genetics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
- Correspondence:
| | - Peter Devilee
- Department of Human Genetics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
- Department of Pathology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
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Alzahrani AS, Alswailem M, Murugan AK, Alghamdi B, Al-Hindi H. Papillary thyroid cancer and a TERT promotor mutation-positive paraganglioma in a patient with a germline SDHB mutation. J Endocr Soc 2022; 6:bvac076. [PMID: 35673401 PMCID: PMC9165429 DOI: 10.1210/jendso/bvac076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Indexed: 11/19/2022] Open
Abstract
Abstract
Purpose
About 40% of paragangliomas (PGL) are due to germline mutations in one of several susceptibility genes. These genes rarely predispose to other non-PGL tumors. Here, we describe and functionally characterize a germline SDHB mutation in a patient who developed a BRAFV600E mutation-positive papillary thyroid cancer (PTC) and a TERT promotor mutation-positive PGL.
Experimental design
A 28-year-old asymptomatic man was discovered incidentally to have a large left-sided mid abdominal PGL and PTC. He underwent resection of the PGL and total thyroidectomy and neck dissection followed by I-131 adjuvant therapy for PTC. The histopathology revealed a high-grade PGL and a tall cell variant PTC with lymph node metastases (T1b N1b M0). He soon developed PGL spinal metastases that have been rapidly progressing and is currently being treated with Lu 177-dotatate therapy. Family screening revealed a positive SDHB mutation in the mother, a son and a brother.
Results
In addition to the heterozygous SDHB germline mutation (c.688C>T, p.Arg230Cys), molecular analysis revealed a somatic TERT promotor mutation (C228T) in PGL (negative in PTC), and a somatic BRAFV600E mutation in PTC (negative in PGL). Functional studies showed a higher proliferation rate in the mutant compared to the wild type SDHB.
Conclusion
Germline SDHB mutations rarely occur in patients with PTC and may contribute to the its aggressiveness. Somatic TERT promotor mutations rarely occur in PGL and contribute to its aggressiveness and metastatic potential.
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Affiliation(s)
- Ali S Alzahrani
- Department of Molecular Oncology, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
- Department of Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Meshael Alswailem
- Department of Molecular Oncology, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | | | - Balgees Alghamdi
- Department of Molecular Oncology, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Hindi Al-Hindi
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
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Cameselle-Teijeiro JM, Mete O, Asa SL, LiVolsi V. Inherited Follicular Epithelial-Derived Thyroid Carcinomas: From Molecular Biology to Histological Correlates. Endocr Pathol 2021; 32:77-101. [PMID: 33495912 PMCID: PMC7960606 DOI: 10.1007/s12022-020-09661-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/21/2020] [Indexed: 12/12/2022]
Abstract
Cancer derived from thyroid follicular epithelial cells is common; it represents the most common endocrine malignancy. The molecular features of sporadic tumors have been clarified in the past decade. However the incidence of familial disease has not been emphasized and is often overlooked in routine practice. A careful clinical documentation of family history or familial syndromes that can be associated with thyroid disease can help identify germline susceptibility-driven thyroid neoplasia. In this review, we summarize a large body of information about both syndromic and non-syndromic familial thyroid carcinomas. A significant number of patients with inherited non-medullary thyroid carcinomas manifest disease that appears to be sporadic disease even in some syndromic cases. The cytomorphology of the tumor(s), molecular immunohistochemistry, the findings in the non-tumorous thyroid parenchyma and other associated lesions may provide insight into the underlying syndromic disorder. However, the increasing evidence of familial predisposition to non-syndromic thyroid cancers is raising questions about the importance of genetics and epigenetics. What appears to be "sporadic" is becoming less often truly so and more often an opportunity to identify and understand novel genetic variants that underlie tumorigenesis. Pathologists must be aware of the unusual morphologic features that should prompt germline screening. Therefore, recognition of harbingers of specific germline susceptibility syndromes can assist in providing information to facilitate early detection to prevent aggressive disease.
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Affiliation(s)
- José Manuel Cameselle-Teijeiro
- Department of Pathology, Galician Healthcare Service (SERGAS), Clinical University Hospital, Travesía Choupana s/n, 15706, Santiago de Compostela, Spain.
- Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
- Medical Faculty, University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Ozgur Mete
- Department of Pathology and Endocrine Oncology Site, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Sylvia L Asa
- Department of Pathology, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Virginia LiVolsi
- Department of Pathology and Laboratory Medicine, Perelmann School of Medicine of the University of Pennsylvania, Philadelphia, PA, USA
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The roles of SDHAF2 and dicarboxylate in covalent flavinylation of SDHA, the human complex II flavoprotein. Proc Natl Acad Sci U S A 2020; 117:23548-23556. [PMID: 32887801 DOI: 10.1073/pnas.2007391117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial complex II, also known as succinate dehydrogenase (SDH), is an integral-membrane heterotetramer (SDHABCD) that links two essential energy-producing processes, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. A significant amount of information is available on the structure and function of mature complex II from a range of organisms. However, there is a gap in our understanding of how the enzyme assembles into a functional complex, and disease-associated complex II insufficiency may result from incorrect function of the mature enzyme or from assembly defects. Here, we investigate the assembly of human complex II by combining a biochemical reconstructionist approach with structural studies. We report an X-ray structure of human SDHA and its dedicated assembly factor SDHAF2. Importantly, we also identify a small molecule dicarboxylate that acts as an essential cofactor in this process and works in synergy with SDHAF2 to properly orient the flavin and capping domains of SDHA. This reorganizes the active site, which is located at the interface of these domains, and adjusts the pKa of SDHAR451 so that covalent attachment of the flavin adenine dinucleotide (FAD) cofactor is supported. We analyze the impact of disease-associated SDHA mutations on assembly and identify four distinct conformational forms of the complex II flavoprotein that we assign to roles in assembly and catalysis.
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