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Zhang Y, Zhao H, Fu X, Wang K, Yang J, Zhang X, Wang H. The role of hydrogen sulfide regulation of pyroptosis in different pathological processes. Eur J Med Chem 2024; 268:116254. [PMID: 38377826 DOI: 10.1016/j.ejmech.2024.116254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/31/2024] [Accepted: 02/15/2024] [Indexed: 02/22/2024]
Abstract
Pyroptosis is one kind of programmed cell death in which the cell membrane ruptures and subsequently releases cell contents and pro-inflammatory cytokines including IL-1β and IL-18. Pyroptosis is caused by many types of pathological stimuli, such as hyperglycemia (HG), oxidative stress, and inflammation, and is mediated by gasdermin (GSDM) protein family. Increasing evidence indicates that pyroptosis plays an important role in multiple diseases, such as cancer, kidney diseases, inflammatory diseases, and cardiovascular diseases. Therefore, the regulation of pyroptosis is crucial for the occurrence, development, and treatment of many diseases. Hydrogen sulfide (H2S) is a biologically active gasotransmitter following carbon monoxide (CO) and nitrogen oxide (NO) in mammalian tissues. So far, three enzymes, including 3-mercaptopyruvate sulphurtransferase (3-MST), cystathionine γ- Lyase (CSE), and Cystine β-synthesis enzyme (CBS), have been found to catalyze the production of endogenous H2S in mammals. H2S has been reported to have multiple biological functions including anti-inflammation, anti-oxidative stress, anti-apoptosis and so on. Hence, H2S is involved in various physiological and pathological processes. In recent years, many studies have demonstrated that H2S plays a critical role by regulating pyroptosis in various pathological processes, such as ischemia-reperfusion injury, alcoholic liver disease, and diabetes cardiomyopathy. However, the relevant mechanism has not been completely understood. Therefore, elucidating the mechanism by which H2S regulates pyroptosis in diseases will help understand the pathogenesis of multiple diseases and provide important new avenues for the treatment of many diseases. Here, we reviewed the progress of H2S regulation of pyroptosis in different pathological processes, and analyzed the molecular mechanism in detail to provide a theoretical reference for future related research.
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Affiliation(s)
- Yanting Zhang
- School of Basic Medical Sciences, Henan University, Kaifeng, Henan, 475004, China; School of Clinical Medicine, Henan University, Kaifeng, Henan, 475004, China
| | - Huijie Zhao
- Institute of Chronic Disease Risks Assessment, Henan University, Jinming Avenue, Kaifeng, 475004, China
| | - Xiaodi Fu
- School of Basic Medical Sciences, Henan University, Kaifeng, Henan, 475004, China
| | - Kexiao Wang
- School of Clinical Medicine, Henan University, Kaifeng, Henan, 475004, China
| | - Jiahao Yang
- School of Clinical Medicine, Henan University, Kaifeng, Henan, 475004, China
| | | | - Honggang Wang
- School of Basic Medical Sciences, Henan University, Kaifeng, Henan, 475004, China.
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Santos SS, Rodrigues LDOCP, Martins V, Petrosino M, Zuhra K, Ascenção K, Anand A, Abdel-Kader RM, Gad MZ, Bourquin C, Szabo C. Role of Cystathionine β-Synthase and 3-Mercaptopyruvate Sulfurtransferase in the Regulation of Proliferation, Migration, and Bioenergetics of Murine Breast Cancer Cells. Antioxidants (Basel) 2023; 12:antiox12030647. [PMID: 36978895 PMCID: PMC10045476 DOI: 10.3390/antiox12030647] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
Cystathionine β-synthase (CBS), CSE (cystathionine γ-lyase) and 3-mercaptopyruvate sulfurtransferase (3-MST) have emerged as three significant sources of hydrogen sulfide (H2S) in various forms of mammalian cancer. Here, we investigated the functional role of CBS’ and 3-MST’s catalytic activity in the murine breast cancer cell line EO771. The CBS/CSE inhibitor aminooxyacetic acid (AOAA) and the 3-MST inhibitor 2-[(4-hydroxy-6-methylpyrimidin-2-yl)sulfanyl]-1-(naphthalen-1-yl)ethan-1-one (HMPSNE) were used to assess the role of endogenous H2S in the modulation of breast cancer cell proliferation, migration, bioenergetics and viability in vitro. Methods included measurements of cell viability (MTT and LDH assays), cell proliferation and in vitro wound healing (IncuCyte) and cellular bioenergetics (Seahorse extracellular flux analysis). CBS and 3-MST, as well as expression were detected by Western blotting; H2S production was measured by the fluorescent dye AzMC. The results show that EO771 cells express CBS, CSE and 3-MST protein, as well as several enzymes involved in H2S degradation (SQR, TST, and ETHE1). Pharmacological inhibition of CBS or 3-MST inhibited H2S production, suppressed cellular bioenergetics and attenuated cell proliferation. Cell migration was only inhibited by the 3-MST inhibitor, but not the CBS/CSE inhibitor. Inhibition of CBS/CSE of 3-MST did not significantly affect basal cell viability; inhibition of 3-MST (but not of CBS/CSE) slightly enhanced the cytotoxic effects of oxidative stress (hydrogen peroxide challenge). From these findings, we conclude that endogenous H2S, generated by 3-MST and to a lower degree by CBS/CSE, significantly contributes to the maintenance of bioenergetics, proliferation and migration in murine breast cancer cells and may also exert a minor role as a cytoprotectant.
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Affiliation(s)
- Sidneia Sousa Santos
- Department of Medicine, Division of Infectious Diseases, Escola Paulista de Medicina, Federal University of São Paulo (EPM/UNIFESP), São Paulo 04023, Brazil
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Larissa de Oliveira Cavalcanti Peres Rodrigues
- Department of Medicine, Division of Infectious Diseases, Escola Paulista de Medicina, Federal University of São Paulo (EPM/UNIFESP), São Paulo 04023, Brazil
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Vanessa Martins
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Maria Petrosino
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Karim Zuhra
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Kelly Ascenção
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Abhishek Anand
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Reham Mahmoud Abdel-Kader
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo 11511, Egypt
| | - Mohamed Z. Gad
- Department of Biochemistry, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo 11511, Egypt
| | - Carole Bourquin
- School of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland, Department of Anaesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Csaba Szabo
- Chair of Pharmacology, Section of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
- Correspondence:
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Panagaki T, Randi EB, Szabo C, Hölscher C. Incretin Mimetics Restore the ER-Mitochondrial Axis and Switch Cell Fate Towards Survival in LUHMES Dopaminergic-Like Neurons: Implications for Novel Therapeutic Strategies in Parkinson's Disease. JOURNAL OF PARKINSON'S DISEASE 2023; 13:1149-1174. [PMID: 37718851 PMCID: PMC10657688 DOI: 10.3233/jpd-230030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/25/2023] [Indexed: 09/19/2023]
Abstract
BACKGROUND Parkinson's disease (PD) is a progressive neurodegenerative movement disorder that afflicts more than 10 million people worldwide. Available therapeutic interventions do not stop disease progression. The etiopathogenesis of PD includes unbalanced calcium dynamics and chronic dysfunction of the axis of the endoplasmic reticulum (ER) and mitochondria that all can gradually favor protein aggregation and dopaminergic degeneration. OBJECTIVE In Lund Human Mesencephalic (LUHMES) dopaminergic-like neurons, we tested novel incretin mimetics under conditions of persistent, calcium-dependent ER stress. METHODS We assessed the pharmacological effects of Liraglutide-a glucagon-like peptide-1 (GLP-1) analog-and the dual incretin GLP-1/GIP agonist DA3-CH in the unfolded protein response (UPR), cell bioenergetics, mitochondrial biogenesis, macroautophagy, and intracellular signaling for cell fate in terminally differentiated LUHMES cells. Cells were co-stressed with the sarcoplasmic reticulum calcium ATPase (SERCA) inhibitor, thapsigargin. RESULTS We report that Liraglutide and DA3-CH analogs rescue the arrested oxidative phosphorylation and glycolysis. They mitigate the suppressed mitochondrial biogenesis and hyper-polarization of the mitochondrial membrane, all to re-establish normalcy of mitochondrial function under conditions of chronic ER stress. These effects correlate with a resolution of the UPR and the deficiency of components for autophagosome formation to ultimately halt the excessive synaptic and neuronal death. Notably, the dual incretin displayed a superior anti-apoptotic effect, when compared to Liraglutide. CONCLUSIONS The results confirm the protective effects of incretin signaling in ER and mitochondrial stress for neuronal degeneration management and further explain the incretin-derived effects observed in PD patients.
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Affiliation(s)
- Theodora Panagaki
- Faculty of Science & Medicine, University of Fribourg, Fribourg, Switzerland
| | - Elisa B. Randi
- Faculty of Science & Medicine, University of Fribourg, Fribourg, Switzerland
| | - Csaba Szabo
- Faculty of Science & Medicine, University of Fribourg, Fribourg, Switzerland
| | - Christian Hölscher
- Research & Experimental Center, Henan University of Chinese Medicine, Zhengzhou, China
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Panagaki T, Pecze L, Randi EB, Nieminen AI, Szabo C. Role of the cystathionine β-synthase / H 2S pathway in the development of cellular metabolic dysfunction and pseudohypoxia in down syndrome. Redox Biol 2022; 55:102416. [PMID: 35921774 PMCID: PMC9356176 DOI: 10.1016/j.redox.2022.102416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/10/2022] [Accepted: 07/17/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Overexpression of the transsulfuration enzyme cystathionine-β-synthase (CBS), and overproduction of its product, hydrogen sulfide (H2S) are recognized as potential pathogenetic factors in Down syndrome (DS). The purpose of the study was to determine how the mitochondrial function and core metabolic pathways are affected by DS and how pharmacological inhibition of CBS affects these parameters. METHODS 8 human control and 8 human DS fibroblast cell lines have been subjected to bioenergetic and fluxomic and proteomic analysis with and without treatment with a pharmacological inhibitor of CBS. RESULTS DS cells exhibited a significantly higher CBS expression than control cells, and produced more H2S. They also exhibited suppressed mitochondrial electron transport and oxygen consumption and suppressed Complex IV activity, impaired cell proliferation and increased ROS generation. Inhibition of H2S biosynthesis with aminooxyacetic acid reduced cellular H2S, improved cellular bioenergetics, attenuated ROS and improved proliferation. 13C glucose fluxomic analysis revealed that DS cells exhibit a suppression of the Krebs cycle activity with a compensatory increase in glycolysis. CBS inhibition restored the flux from glycolysis to the Krebs cycle and reactivated oxidative phosphorylation. Proteomic analysis revealed no CBS-dependent alterations in the expression level of the enzymes involved in glycolysis, oxidative phosphorylation and the pentose phosphate pathway. DS was associated with the dysregulation of several components of the autophagy network; CBS inhibition normalized several of these parameters. CONCLUSIONS Increased H2S generation in DS promotes pseudohypoxia and contributes to cellular metabolic dysfunction by causing a shift from oxidative phosphorylation to glycolysis.
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Affiliation(s)
- Theodora Panagaki
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Laszlo Pecze
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Elisa B Randi
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Anni I Nieminen
- Metabolomics Unit, Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Csaba Szabo
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
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Aroca A, Gotor C. Hydrogen sulfide action in the regulation of plant autophagy. FEBS Lett 2022; 596:2186-2197. [PMID: 35735749 DOI: 10.1002/1873-3468.14433] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/30/2022] [Accepted: 06/13/2022] [Indexed: 11/09/2022]
Abstract
Hydrogen sulfide is a signaling molecule with a well-established impact on both plant and animal physiology. Intense investigation into the regulation of autophagy by sulfide in Arabidopsis thaliana has revealed that the post-translational modification of persulfidation/S-sulfhydration plays a key role. In this review focused on plants, we discuss the nature of the sulfide molecule involved in the regulation of autophagy, the final outcome of this modification, and the persulfidated autophagy proteins identified so far. A detailed outline of the actual knowledge of the regulation mechanism of the autophagy-related proteins ATG4a and ATG18a from Arabidopsis by sulfide is also included. This information will be instrumental for furthering research on the regulation of autophagy by sulfide.
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Affiliation(s)
- Angeles Aroca
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Seville, Spain
| | - Cecilia Gotor
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Seville, Spain
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Cirino G, Szabo C, Papapetropoulos A. Physiological roles of hydrogen sulfide in mammalian cells, tissues and organs. Physiol Rev 2022; 103:31-276. [DOI: 10.1152/physrev.00028.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
H2S belongs to the class of molecules known as gasotransmitters, which also includes nitric oxide (NO) and carbon monoxide (CO). Three enzymes are recognized as endogenous sources of H2S in various cells and tissues: cystathionine g-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current article reviews the regulation of these enzymes as well as the pathways of their enzymatic and non-enzymatic degradation and elimination. The multiple interactions of H2S with other labile endogenous molecules (e.g. NO) and reactive oxygen species are also outlined. The various biological targets and signaling pathways are discussed, with special reference to H2S and oxidative posttranscriptional modification of proteins, the effect of H2S on channels and intracellular second messenger pathways, the regulation of gene transcription and translation and the regulation of cellular bioenergetics and metabolism. The pharmacological and molecular tools currently available to study H2S physiology are also reviewed, including their utility and limitations. In subsequent sections, the role of H2S in the regulation of various physiological and cellular functions is reviewed. The physiological role of H2S in various cell types and organ systems are overviewed. Finally, the role of H2S in the regulation of various organ functions is discussed as well as the characteristic bell-shaped biphasic effects of H2S. In addition, key pathophysiological aspects, debated areas, and future research and translational areas are identified A wide array of significant roles of H2S in the physiological regulation of all organ functions emerges from this review.
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Affiliation(s)
- Giuseppe Cirino
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Csaba Szabo
- Chair of Pharmacology, Section of Medicine, University of Fribourg, Switzerland
| | - Andreas Papapetropoulos
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece & Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Greece
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7
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Wang Y, Ni X, Chadha R, McCartney C, Lam Y, Brummett B, Ramush G, Xian M. Methods for Suppressing Hydrogen Sulfide in Biological Systems. Antioxid Redox Signal 2022; 36:294-308. [PMID: 34162216 PMCID: PMC8865628 DOI: 10.1089/ars.2021.0088] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Significance: Hydrogen sulfide (H2S) plays critical roles in redox biology, and its regulatory effects are tightly controlled by its cellular location and concentration. The imbalance of H2S is believed to contribute to some pathological processes. Recent Advances: Downregulation of H2S requires chemical tools such as inhibitors of H2S-producing enzymes and H2S scavengers. Recent efforts have discovered some promising inhibitors and scavengers. These advances pave the road toward better understanding of the functions of H2S. Critical Issues: Precise H2S downregulation is challenging. The potency and specificity of current inhibitors are still far from ideal. H2S-producing enzymes are involved in complex sulfur metabolic pathways and ubiquitously present in biological matrices. The inhibition of these enzymes can cause unwanted side effects. H2S scavengers allow targeted H2S clearance, but their options are still limited. In addition, the scavenging process often results in biologically active by-products. Future Directions: Further development of potent and specific inhibitors for H2S-producing enzymes is needed. Scavengers that can rapidly and selectively remove H2S while generating biocompatible by-products are needed. Potential therapeutic applications of scavengers and inhibitors are worth exploring. Antioxid. Redox Signal. 36, 294-308.
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Affiliation(s)
- Yingying Wang
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Xiang Ni
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Rahuljeet Chadha
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Caitlin McCartney
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Yannie Lam
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Brock Brummett
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Geat Ramush
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
| | - Ming Xian
- Department of Chemistry, Brown University, Providence, Rhode Island, USA
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Panagaki T, Lozano-Montes L, Janickova L, Zuhra K, Szabo MP, Majtan T, Rainer G, Maréchal D, Herault Y, Szabo C. Overproduction of hydrogen sulfide, generated by cystathionine β-synthase, disrupts brain wave patterns and contributes to neurobehavioral dysfunction in a rat model of down syndrome. Redox Biol 2022; 51:102233. [PMID: 35042677 PMCID: PMC9039679 DOI: 10.1016/j.redox.2022.102233] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/26/2021] [Accepted: 01/10/2022] [Indexed: 12/23/2022] Open
Abstract
Using a novel rat model of Down syndrome (DS), the functional role of the cystathionine-β-synthase (CBS)/hydrogen sulfide (H2S) pathway was investigated on the pathogenesis of brain wave pattern alterations and neurobehavioral dysfunction. Increased expression of CBS and subsequent overproduction of H2S was observed in the brain of DS rats, with CBS primarily localizing to astrocytes and the vasculature. DS rats exhibited neurobehavioral defects, accompanied by a loss of gamma brain wave activity and a suppression of the expression of multiple pre- and postsynaptic proteins. Aminooxyacetate, a prototypical pharmacological inhibitor of CBS, increased the ability of the DS brain tissue to generate ATP in vitro and reversed the electrophysiological and neurobehavioral alterations in vivo. Thus, the CBS/H2S pathway contributes to the pathogenesis of neurological dysfunction in DS, most likely through dysregulation of cellular bioenergetics and gene expression.
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Affiliation(s)
- Theodora Panagaki
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Laura Lozano-Montes
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland; Visual Cognition Laboratory, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Lucia Janickova
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Karim Zuhra
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Marcell P Szabo
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Tomas Majtan
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Gregor Rainer
- Visual Cognition Laboratory, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Damien Maréchal
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
| | - Csaba Szabo
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
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Szabo C. Hydrogen Sulfide, an Endogenous Stimulator of Mitochondrial Function in Cancer Cells. Cells 2021; 10:cells10020220. [PMID: 33499368 PMCID: PMC7911547 DOI: 10.3390/cells10020220] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 12/12/2022] Open
Abstract
Hydrogen sulfide (H2S) has a long history as toxic gas and environmental hazard; inhibition of cytochrome c oxidase (mitochondrial Complex IV) is viewed as a primary mode of its cytotoxic action. However, studies conducted over the last two decades unveiled multiple biological regulatory roles of H2S as an endogenously produced mammalian gaseous transmitter. Cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST) are currently viewed as the principal mammalian H2S-generating enzymes. In contrast to its inhibitory (toxicological) mitochondrial effects, at lower (physiological) concentrations, H2S serves as a stimulator of electron transport in mammalian mitochondria, by acting as an electron donor—with sulfide:quinone oxidoreductase (SQR) being the immediate electron acceptor. The mitochondrial roles of H2S are significant in various cancer cells, many of which exhibit high expression and partial mitochondrial localization of various H2S producing enzymes. In addition to the stimulation of mitochondrial ATP production, the roles of endogenous H2S in cancer cells include the maintenance of mitochondrial organization (protection against mitochondrial fission) and the maintenance of mitochondrial DNA repair (via the stimulation of the assembly of mitochondrial DNA repair complexes). The current article overviews the state-of-the-art knowledge regarding the mitochondrial functions of endogenously produced H2S in cancer cells.
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Affiliation(s)
- Csaba Szabo
- Chair of Pharmacology, Section of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
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