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Nature Communications Jul 2022Succinate dehydrogenase, which is known as mitochondrial complex II, has proven to be a fascinating machinery, attracting renewed and increased interest in its...
Succinate dehydrogenase, which is known as mitochondrial complex II, has proven to be a fascinating machinery, attracting renewed and increased interest in its involvement in human diseases. Herein, we find that succinate dehydrogenase assembly factor 4 (SDHAF4) is downregulated in cardiac muscle in response to pathological stresses and in diseased hearts from human patients. Cardiac loss of Sdhaf4 suppresses complex II assembly and results in subunit degradation and complex II deficiency in fetal mice. These defects are exacerbated in young adults with globally impaired metabolic capacity and activation of dynamin-related protein 1, which induces excess mitochondrial fission and mitophagy, thereby causing progressive dilated cardiomyopathy and lethal heart failure in animals. Targeting mitochondria via supplementation with fumarate or inhibiting mitochondrial fission improves mitochondrial dynamics, partially restores cardiac function and prolongs the lifespan of mutant mice. Moreover, the addition of fumarate is found to dramatically improve cardiac function in myocardial infarction mice. These findings reveal a vital role for complex II assembly in the development of dilated cardiomyopathy and provide additional insights into therapeutic interventions for heart diseases.
Topics: Animals; Cardiomyopathy, Dilated; Fumarates; Mice; Mitochondrial Dynamics; Mitophagy; Myocytes, Cardiac; Succinate Dehydrogenase
PubMed: 35803927
DOI: 10.1038/s41467-022-31548-1 -
Surgical Pathology Clinics Dec 2019Pheochromocytomas and extra-adrenal paragangliomas are rare neuroendocrine neoplasms with characteristic histologic and immunohistochemical features. These tumors can... (Review)
Review
Pheochromocytomas and extra-adrenal paragangliomas are rare neuroendocrine neoplasms with characteristic histologic and immunohistochemical features. These tumors can arise in several anatomic locations, necessitating that their diagnostic recognition extends beyond the realm of endocrine disorders. A practical and reproducible risk stratification system for these tumors is still in development. In this rapidly evolving era of molecular medicine, it is essential for pathologists to equip themselves with a framework for understanding the classification of paragangliomas and pheochromocytomas and be informed of how they might advise their colleagues with regard to prognostication and appropriate follow-up.
Topics: Adrenal Gland Neoplasms; Biomarkers, Tumor; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Immunohistochemistry; Mutation; Neoplasm Grading; Paraganglioma; Pheochromocytoma; Succinate Dehydrogenase
PubMed: 31672301
DOI: 10.1016/j.path.2019.08.009 -
Molecular and Cellular Endocrinology Jul 2018In this report, we review the relationship between succinate dehydrogenase (SDH) deficiency and the epigenome, especially with regards to two clinical conditions. Carney... (Review)
Review
In this report, we review the relationship between succinate dehydrogenase (SDH) deficiency and the epigenome, especially with regards to two clinical conditions. Carney triad (CT) is a very rare disease with synchronous or metachronous occurrence of at least three different tumor entities; gastric gastrointestinal stromal tumor (GIST), paraganglioma (PGL), and pulmonary chondroma. This condition affects mostly females and it is never inherited. Another disease that shares two of the tumor components of CT, namely GIST and PGL is the Carney-Stratakis syndrome (CSS) or dyad. CSS affects both genders during childhood and adolescence. We review herein the main clinical features and molecular mechanisms behind those two syndromes that share quite a bit of similarities, but one is non-hereditary (CT) whereas the other shows an autosomal-dominant, with incomplete penetrance, inheritance pattern (CSS). Both CT and CSS are caused by the deficiency of the succinate dehydrogenase (SDH) enzyme. The key difference between the two syndromes is the molecular mechanism that causes the SDH deficiency. Most cases of CT show down-regulation of SDH through site-specific hyper-methylation of the SDHC gene, whereas CSS cases carry inactivating germline mutations within one of the genes coding for the SDH subunits A, B, C, or D (SDHA, SDHB, SDHC, and SDHD). There is only partial overlap between the two conditions (there are a few patients with CT that have SDH subunit mutations) but both lead to increased methylation of the entire genome in the tumors associated with them. Other tumors (outside CT and CSS) that have SDH deficiency are associated with increased methylation of the entire genome, but only in CT there is site-specific methylation of the SDHC gene. These findings have implications for diagnostics and the treatment of patients with these, often metastatic tumors.
Topics: Carcinogenesis; Chondroma; Epigenomics; Germ-Line Mutation; Humans; Leiomyosarcoma; Lung Neoplasms; Paraganglioma, Extra-Adrenal; Stomach Neoplasms; Succinate Dehydrogenase
PubMed: 28739378
DOI: 10.1016/j.mce.2017.07.018 -
Medecine Sciences : M/S Mar 2022Succinate dehydrogenase (SDH) is a mitochondrial enzyme that participates in both the tricarboxylic acid cycle and the electron transport chain. Mutations in genes...
Succinate dehydrogenase (SDH) is a mitochondrial enzyme that participates in both the tricarboxylic acid cycle and the electron transport chain. Mutations in genes encoding SDH are responsible for a predisposition to pheochromocytomas and paragangliomas, and more rarely, to gastrointestinal stromal tumors or renal cell carcinomas. A decrease in SDH activity, not explained by genetics, has also been observed in more common cancers. One of the consequences of the inactivation of SDH is the excessive production of its substrate, succinate, which acts as an oncometabolite by promoting a pseudohypoxic status and an extensive epigenetic rearrangement. Understanding SDH-related oncogenesis now makes it possible to develop innovative diagnostic methods and to consider targeted therapies for the management of affected patients.
Topics: Adrenal Gland Neoplasms; Gastrointestinal Stromal Tumors; Humans; Paraganglioma; Pheochromocytoma; Succinate Dehydrogenase
PubMed: 35333162
DOI: 10.1051/medsci/2022024 -
Archives of Pathology & Laboratory... Dec 2018Succinate dehydrogenase (SDH) is uniquely tasked with a dual role in the essential energy-producing processes of a cell. Although SDH subunits and assembly factors form... (Review)
Review
Succinate dehydrogenase (SDH) is uniquely tasked with a dual role in the essential energy-producing processes of a cell. Although SDH subunits and assembly factors form part of the same enzyme complex, mutations in their respective genes lead to significantly different clinical phenotypes. Remarkable discoveries in the last 17 years have led to the delineation of the SDH complex deficiency syndrome and its multiple pathogenic branches. Here we provide an updated overview of SDH deficiency in order to raise awareness of its multiple connotations including nonneoplastic associations and pertinent features of the continually growing list of SDH-mutant tumors so as to better direct genetic counseling and predict prognosis.
Topics: Electron Transport Complex II; Humans; Multienzyme Complexes; Mutation; Neoplasms; Phenotype; Succinate Dehydrogenase
PubMed: 30289269
DOI: 10.5858/arpa.2017-0285-RS -
Critical Reviews in Biochemistry and... 2015Succinate dehydrogenase (or complex II; SDH) is a heterotetrameric protein complex that links the tribarboxylic acid cycle with the electron transport chain. SDH is... (Review)
Review
Succinate dehydrogenase (or complex II; SDH) is a heterotetrameric protein complex that links the tribarboxylic acid cycle with the electron transport chain. SDH is composed of four nuclear-encoded subunits that must translocate independently to the mitochondria and assemble into a mature protein complex embedded in the inner mitochondrial membrane. Recently, it has become clear that failure to assemble functional SDH complexes can result in cancer and neurodegenerative syndromes. The effort to thoroughly elucidate the SDH assembly pathway has resulted in the discovery of four subunit-specific assembly factors that aid in the maturation of individual subunits and support the assembly of the intact complex. This review will focus on these assembly factors and assess the contribution of each factor to the assembly of SDH. Finally, we propose a model of the SDH assembly pathway that incorporates all extant data.
Topics: Catalytic Domain; Cell Nucleus; Electron Transport; Humans; Mitochondria; Protein Conformation; Protein Subunits; Succinate Dehydrogenase
PubMed: 25488574
DOI: 10.3109/10409238.2014.990556 -
Trends in Biochemical Sciences Apr 2017Mitochondrial complex II (CII), also called succinate dehydrogenase (SDH), is a central purveyor of the reprogramming of metabolic and respiratory adaptation in response... (Review)
Review
Mitochondrial complex II (CII), also called succinate dehydrogenase (SDH), is a central purveyor of the reprogramming of metabolic and respiratory adaptation in response to various intrinsic and extrinsic stimuli and abnormalities. In this review we discuss recent findings regarding SDH biogenesis, which requires four known assembly factors, and modulation of its enzymatic activity by acetylation, succinylation, phosphorylation, and proteolysis. We further focus on the emerging role of both genetic and epigenetic aberrations leading to SDH dysfunction associated with various clinical manifestations. This review also covers the recent discovery of the role of SDH in inflammation-linked pathologies. Conceivably, SDH is a potential target for several hard-to-treat conditions, including cancer, that remains to be fully exploited.
Topics: Animals; Humans; Inflammation; Mitochondria; Succinate Dehydrogenase
PubMed: 28185716
DOI: 10.1016/j.tibs.2017.01.003 -
Experimental Biology and Medicine... Feb 2023Succinate dehydrogenase complex subunit C () is a subunit of mitochondrial complex II (MCII), which is also known as succinate dehydrogenase (SDH) or succinate:... (Review)
Review
Succinate dehydrogenase complex subunit C () is a subunit of mitochondrial complex II (MCII), which is also known as succinate dehydrogenase (SDH) or succinate: ubiquinone oxidoreductase. Mitochondrial complex II is the smallest respiratory complex in the respiratory chain and contains four subunits. is a membrane-anchored subunit of SDH, which connects the tricarboxylic acid cycle and the electron transport chain. SDH regulates several physiological processes within cells, plays an important role in generating energy to maintain normal cell growth, and is involved in apoptosis. Currently, is generally recognized as a tumor-suppressor gene. mutations can cause oxidative damage in the body. It is closely related to the occurrence and development of cancer, neurodegenerative diseases, and aging-related diseases. Here, we review studies on the structure, biological function, related diseases of , and the Animal Model of Mutation and its potential use as a therapeutic target of certain human diseases.
Topics: Animals; Humans; Succinate Dehydrogenase; Mutation; Citric Acid Cycle; Oxidative Stress; Cell Proliferation
PubMed: 36691338
DOI: 10.1177/15353702221147567 -
European Urology Focus Sep 2022Succinate dehydrogenase-deficient and fumarate hydratase-deficient renal cell carcinomas (SDHRCC and FHRCC) are rare kidney cancers driven by loss of TCA cycle enzymes.
BACKGROUND
Succinate dehydrogenase-deficient and fumarate hydratase-deficient renal cell carcinomas (SDHRCC and FHRCC) are rare kidney cancers driven by loss of TCA cycle enzymes.
OBJECTIVE
To define and compare the genomic and metabolomic hallmarks of SDHRCC and FHRCC.
DESIGN, SETTING, AND PARTICIPANTS
We analyzed SDHRCC and FHRCC tumors with either immunohistochemical evidence of loss of protein expression or genomically confirmed biallelic inactivation of SDHA/B/C/D/AF2 or FH.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS
Somatic alterations were identified using clinical pipelines, with allele-specific copy number alterations (CNAs) identified using FACETS. Mass spectrometry-based metabolomic profiling was performed on available SDHRCC and FHRCC tumors.
RESULTS AND LIMITATIONS
Tumors were analyzed for 42 patients (25 FHRCC, 17 SDHRCC). In the germline analysis, 16/17 SDHRCCs harbored a germline alteration in SDHB, whereas only 17/22 FHRCCs had pathogenic germline FH variants. SDHRCCs had a lower mutation burden (p = 0.02) and CNA burden (p = 0.0002) than FHRCCs. All SDHRCCs presented with deletion of chromosome 1p (overlapping SDHB), whereas FHRCCs demonstrated high but not ubiquitous loss of 1q (FH locus). Both SDHRCCs and FHRCCs exhibited significant idiopathic accumulation of the metabolite guanine. FHRCC tumors had elevated levels of urea cycle metabolites (argininosuccinate, citrulline, and fumarate), whereas SDHRCC tumors had elevation of numerous acylcarnitines. These characteristic metabolic changes allowed identification of a previously unrecognized SDH-deficient RCC.
CONCLUSIONS
Despite sharing similar genetic etiology, SDHRCC and FHRCC represent distinct molecular entities with unique genetic and metabolic abnormalities.
PATIENT SUMMARY
Kidney cancers driven by loss of the gene encoding either the succinate dehydrogenase or fumarate hydratase enzyme are rare. We sought to define and compare the genetic and metabolic features of these cancer entities.
Topics: Humans; Carcinoma, Renal Cell; Fumarate Hydratase; Succinate Dehydrogenase; Kidney Neoplasms; Genomics
PubMed: 35288096
DOI: 10.1016/j.euf.2021.12.002 -
International Journal of Molecular... Feb 2023Succinate dehydrogenase (SDH) is one of the enzymes of the tricarboxylic acid cycle (Krebs cycle) and complex II of the mitochondrial respiratory chain. A class of... (Review)
Review
Succinate dehydrogenase (SDH) is one of the enzymes of the tricarboxylic acid cycle (Krebs cycle) and complex II of the mitochondrial respiratory chain. A class of fungicides (SDHIs) targets the complex II reaction in the SDH. A large number of those in use have been shown to inhibit SDH in other phyla, including humans. This raises questions about possible effects on human health and non-target organisms in the environment. The present document will address metabolic consequences in mammals; it is neither a review on SDH nor is it about the toxicology of SDHIs. Most clinically relevant observations are linked to a severe decrease in SDH activity. Here we shall examine the mechanisms for compensating a loss of SDH activity and their possible weaknesses or adverse consequences. It can be expected that a mild inhibition of SDH will be compensated by the kinetic properties of this enzyme, but this implies a proportionate increase in succinate concentration. This would be relevant for succinate signaling and epigenetics (not reviewed here). With regard to metabolism, exposure of the liver to SDHIs would increase the risk for non-alcoholic fatty liver disease (NAFLD). Higher levels of inhibition may be compensated by modification of metabolic fluxes with net production of succinate. SDHIs are much more soluble in lipids than in water; consequently, a different diet composition between laboratory animals and humans is expected to influence their absorption.
Topics: Animals; Humans; Pesticides; Succinate Dehydrogenase; Fungicides, Industrial; Energy Metabolism; Succinates; Mammals
PubMed: 36835457
DOI: 10.3390/ijms24044045