1
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Zhang Y, Chen M, Chen X, Zhang M, Yin J, Yang Z, Gao X, Zhang S, Yang M. Molecular architecture of the mammalian 2-oxoglutarate dehydrogenase complex. Nat Commun 2024; 15:8407. [PMID: 39333186 PMCID: PMC11436768 DOI: 10.1038/s41467-024-52792-7] [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: 12/19/2023] [Accepted: 09/23/2024] [Indexed: 09/29/2024] Open
Abstract
The 2-oxoglutarate dehydrogenase complex (OGDHc) orchestrates a critical reaction regulating the TCA cycle. Although the structure of each OGDHc subunit has been solved, the architecture of the intact complex and inter-subunit interactions still remain unknown. Here we report the assembly of native, intact OGDHc from Sus scrofa heart tissue using cryo-electron microscopy (cryo-EM), cryo-electron tomography (cryo-ET), and subtomogram averaging (STA) to discern native structures of the whole complex and each subunit. Our cryo-EM analyses revealed the E2o cubic core structure comprising eight homotrimers at 3.3-Å resolution. More importantly, the numbers, positions and orientations of each OGDHc subunit were determined by cryo-ET and the STA structures of the core were resolved at 7.9-Å with the peripheral subunits reaching nanometer resolution. Although the distribution of the peripheral subunits E1o and E3 vary among complexes, they demonstrate a certain regularity within the position and orientation. Moreover, we analyzed and validated the interactions between each subunit, and determined the flexible binding mode for E1o, E2o and E3, resulting in a proposed model of Sus scrofa OGDHc. Together, our results reveal distinctive factors driving the architecture of the intact, native OGDHc.
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Affiliation(s)
- Yitang Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Maofei Chen
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xudong Chen
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Minghui Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, China
| | - Jian Yin
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Zi Yang
- Technology Center for Protein Research, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xin Gao
- Computer Science Program, Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Sensen Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
- Cryo-EM Facility Center, Southern University of Science & Technology, Shenzhen, China.
- Beijing Life Science Academy, Beijing, China.
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2
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Gao Q, Hägglund P, Gamon LF, Davies MJ. Mapping of oxidative modifications on the alpha-keto glutarate dehydrogenase complex induced by singlet oxygen: Effects on structure and activity. Free Radic Biol Med 2024; 224:723-739. [PMID: 39299525 DOI: 10.1016/j.freeradbiomed.2024.09.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2024] [Revised: 09/06/2024] [Accepted: 09/16/2024] [Indexed: 09/22/2024]
Abstract
The large multi-subunit mitochondrial alpha-keto glutarate dehydrogenase (KGDH) complex plays a key, rate-determining, role in the tricarboxylic acid (Krebs) cycle, catalyzing the conversion of alpha-keto glutarate to succinyl-CoA. This complex is both a source and target of oxidants, but the sites of modification and association with structural changes and activity loss are poorly understood. We report here oxidative modifications induced by Rose Bengal (RB) in the presence of O2, a source of singlet oxygen (1O2). A rapid loss of activity was detected, with this being dependent on light exposure, illumination time, and the presence of RB and O2. Activity loss was enhanced by D2O (consistent with 1O2 involvement), but diminished by both pre- and (to a lesser extent) post-illumination addition of lipoic acid and lipoamide. Aggregates containing all three KGDH subunits were detected on photooxidation. LC-MS experiments provided evidence for oxidation at 45 sites, including specific Met, His, Trp, Tyr residues and the lipoyllysine active-site cofactor. Products include mono- and di-oxygenated species, and kynurenine from Trp. Mapping of the modifications to the 3-D structure showed that these are localized to both the inner channel and the external surface, consistent with reactions of free 1O2, however the sites and extent of modification do not correlate with their solvent accessibility. These products are generated concurrently with loss of activity, indicative of strong links between these events. These data provide evidence for the impairment of KGDH activity by 1O2 via the oxidation of specific residues on the protein subunits of the complex.
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Affiliation(s)
- Qing Gao
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Per Hägglund
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Luke F Gamon
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Michael J Davies
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark.
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3
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Kong W, Lu C. Role of mitochondria in neonatal hypoxic-ischemic encephalopathy. Histol Histopathol 2024; 39:991-1000. [PMID: 38314617 DOI: 10.14670/hh-18-710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Neonatal hypoxic-ischemic encephalopathy, an important cause of death as well as long-term disability in survivors, is caused by oxygen and glucose deprivation, and limited blood flow. Following hypoxic-ischemic injury in the neonatal brain, three main biochemical damages (excitotoxicity, oxidative stress, and exacerbated inflammation) are triggered. Mitochondria are involved in all three cascades. Mitochondria are the nexus of metabolic pathways to offer most of the energy that our body needs. Hypoxic-ischemic injury affects the characteristics of mitochondria, including dynamics, permeability, and ATP production, which also feed back into the process of neonatal hypoxic-ischemic encephalopathy. Mitochondria can be a cellular hub in inflammation, which is another main response of the injured neonatal brain. Some treatments for neonatal hypoxic-ischemic encephalopathy affect the function of mitochondria or target mitochondria, including therapeutic hypothermia and erythropoietin. This review presents the main roles of mitochondria in neonatal hypoxic-ischemic encephalopathy and discusses some potential treatments directed at mitochondria, which may foster the development of new therapeutic strategies for this encephalopathy.
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Affiliation(s)
- Weijing Kong
- Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
| | - Cheng Lu
- Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
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4
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Bouhlel J, Caffin F, Gros-Désormeaux F, Douki T, Benoist JF, Castelli FA, Chu-Van E, Piérard C, Junot C, Fenaille F. Metabolomics Analysis of Rabbit Plasma after Ocular Exposure to Vapors of Sulfur Mustard. Metabolites 2024; 14:349. [PMID: 39057672 PMCID: PMC11279318 DOI: 10.3390/metabo14070349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Sulfur mustard (SM) is a highly potent alkylating vesicant agent and remains a relevant threat to both civilians and military personnel. The eyes are the most sensitive organ after airborne SM exposure, causing ocular injuries with no antidote or specific therapeutics available. In order to identify relevant biomarkers and to obtain a deeper understanding of the underlying biochemical events, we performed an untargeted metabolomics analysis using liquid chromatography coupled to high-resolution mass spectrometry of plasma samples from New Zealand white rabbits ocularly exposed to vapors of SM. Metabolic profiles (332 unique metabolites) from SM-exposed (n = 16) and unexposed rabbits (n = 8) were compared at different time intervals from 1 to 28 days. The observed time-dependent changes in metabolic profiles highlighted the profound dysregulation of the sulfur amino acids, the phenylalanine, the tyrosine and tryptophan pathway, and the polyamine and purine biosynthesis, which could reflect antioxidant and anti-inflammatory activities. Taurine and 3,4-dihydroxy-phenylalanine (Dopa) seem to be specifically related to SM exposure and correspond well with the different phases of ocular damage, while the dysregulation of adenosine, polyamines, and acylcarnitines might be related to ocular neovascularization. Additionally, neither cysteine, N-acetylcysteine, or guanine SM adducts were detected in the plasma of exposed rabbits at any time point. Overall, our study provides an unprecedented view of the plasma metabolic changes post-SM ocular exposure, which may open up the development of potential new treatment strategies.
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Affiliation(s)
- Jihéne Bouhlel
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, MetaboHUB-IDF, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (J.B.); (J.-F.B.); (F.A.C.); (E.C.-V.); (C.J.)
| | - Fanny Caffin
- Institut de Recherche Biomédicale des Armées (IRBA), 91223 Brétigny-sur-Orge, France; (F.C.); (F.G.-D.)
| | - Fanny Gros-Désormeaux
- Institut de Recherche Biomédicale des Armées (IRBA), 91223 Brétigny-sur-Orge, France; (F.C.); (F.G.-D.)
| | - Thierry Douki
- CEA, CNRS, IRIG, SyMMES, Université Grenoble Alpes, 38000 Grenoble, France;
| | - Jean-François Benoist
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, MetaboHUB-IDF, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (J.B.); (J.-F.B.); (F.A.C.); (E.C.-V.); (C.J.)
- Biochemistry Laboratory, APHP, Hôpital Universitaire Necker Enfants Malades, 75015 Paris, France
| | - Florence A. Castelli
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, MetaboHUB-IDF, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (J.B.); (J.-F.B.); (F.A.C.); (E.C.-V.); (C.J.)
| | - Emeline Chu-Van
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, MetaboHUB-IDF, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (J.B.); (J.-F.B.); (F.A.C.); (E.C.-V.); (C.J.)
| | - Christophe Piérard
- Institut de Recherche Biomédicale des Armées (IRBA), 91223 Brétigny-sur-Orge, France; (F.C.); (F.G.-D.)
| | - Christophe Junot
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, MetaboHUB-IDF, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (J.B.); (J.-F.B.); (F.A.C.); (E.C.-V.); (C.J.)
| | - François Fenaille
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, MetaboHUB-IDF, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (J.B.); (J.-F.B.); (F.A.C.); (E.C.-V.); (C.J.)
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5
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Oberholtzer N, Mills S, Mehta S, Chakraborty P, Mehrotra S. Role of antioxidants in modulating anti-tumor T cell immune resposne. Adv Cancer Res 2024; 162:99-124. [PMID: 39069371 DOI: 10.1016/bs.acr.2024.05.003] [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] [Indexed: 07/30/2024]
Abstract
It has been well established that in addition to oxygen's vital in cellular respiration, a disruption of oxygen balance can lead to increased stress and oxidative injury. Similarly, reduced oxygen during tumor proliferation and invasion generates a hypoxic tumor microenvironment, resulting in dysfunction of immune cells and providing a conducive milieu for tumors to adapt and grow. Strategies to improve the persistence tumor reactive T cells in the highly oxidative tumor environment are being pursued for enhancing immunotherapy outcomes. To this end, we have focused on various strategies that can help increase or maintain the antioxidant capacity of T cells, thus reducing their susceptibility to oxidative stress/damage. Herein we lay out an overview on the role of oxygen in T cell signaling and how pathways regulating oxidative stress or antioxidant signaling can be targeted to enhance immunotherapeutic approaches for cancer treatment.
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Affiliation(s)
- Nathaniel Oberholtzer
- Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Stephanie Mills
- Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Shubham Mehta
- Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Paramita Chakraborty
- Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Shikhar Mehrotra
- Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States.
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6
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Mailloux RJ. The emerging importance of the α-keto acid dehydrogenase complexes in serving as intracellular and intercellular signaling platforms for the regulation of metabolism. Redox Biol 2024; 72:103155. [PMID: 38615490 PMCID: PMC11021975 DOI: 10.1016/j.redox.2024.103155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 04/16/2024] Open
Abstract
The α-keto acid dehydrogenase complex (KDHc) class of mitochondrial enzymes is composed of four members: pyruvate dehydrogenase (PDHc), α-ketoglutarate dehydrogenase (KGDHc), branched-chain keto acid dehydrogenase (BCKDHc), and 2-oxoadipate dehydrogenase (OADHc). These enzyme complexes occupy critical metabolic intersections that connect monosaccharide, amino acid, and fatty acid metabolism to Krebs cycle flux and oxidative phosphorylation (OxPhos). This feature also imbues KDHc enzymes with the heightened capacity to serve as platforms for propagation of intracellular and intercellular signaling. KDHc enzymes serve as a source and sink for mitochondrial hydrogen peroxide (mtH2O2), a vital second messenger used to trigger oxidative eustress pathways. Notably, deactivation of KDHc enzymes through reversible oxidation by mtH2O2 and other electrophiles modulates the availability of several Krebs cycle intermediates and related metabolites which serve as powerful intracellular and intercellular messengers. The KDHc enzymes also play important roles in the modulation of mitochondrial metabolism and epigenetic programming in the nucleus through the provision of various acyl-CoAs, which are used to acylate proteinaceous lysine residues. Intriguingly, nucleosomal control by acylation is also achieved through PDHc and KGDHc localization to the nuclear lumen. In this review, I discuss emerging concepts in the signaling roles fulfilled by the KDHc complexes. I highlight their vital function in serving as mitochondrial redox sensors and how this function can be used by cells to regulate the availability of critical metabolites required in cell signaling. Coupled with this, I describe in detail how defects in KDHc function can cause disease states through the disruption of cell redox homeodynamics and the deregulation of metabolic signaling. Finally, I propose that the intracellular and intercellular signaling functions of the KDHc enzymes are controlled through the reversible redox modification of the vicinal lipoic acid thiols in the E2 subunit of the complexes.
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Affiliation(s)
- Ryan J Mailloux
- School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, Canada.
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7
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Yeo XY, Kwon S, Rinai KR, Lee S, Jung S, Park R. A Consolidated Understanding of the Contribution of Redox Dysregulation in the Development of Hearing Impairment. Antioxidants (Basel) 2024; 13:598. [PMID: 38790703 PMCID: PMC11118506 DOI: 10.3390/antiox13050598] [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: 02/22/2024] [Revised: 04/26/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
The etiology of hearing impairment is multifactorial, with contributions from both genetic and environmental factors. Although genetic studies have yielded valuable insights into the development and function of the auditory system, the contribution of gene products and their interaction with alternate environmental factors for the maintenance and development of auditory function requires further elaboration. In this review, we provide an overview of the current knowledge on the role of redox dysregulation as the converging factor between genetic and environmental factor-dependent development of hearing loss, with a focus on understanding the interaction of oxidative stress with the physical components of the peripheral auditory system in auditory disfunction. The potential involvement of molecular factors linked to auditory function in driving redox imbalance is an important promoter of the development of hearing loss over time.
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Affiliation(s)
- Xin Yi Yeo
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore;
- Department of Medical Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
| | - Soohyun Kwon
- Department of Medical Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
- Department of BioNanotechnology, Gachon University, Seongnam 13120, Republic of Korea
| | - Kimberley R. Rinai
- Department of Life Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
| | - Sungsu Lee
- Department of Otolaryngology-Head and Neck Surgery, Chonnam National University Hospital and Medical School, Gwangju 61469, Republic of Korea;
| | - Sangyong Jung
- Department of Medical Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
| | - Raekil Park
- Department of Biomedical Science and Engineering, Gwangju Institute of Science & Technology (GIST), Gwangju 61005, Republic of Korea
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8
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Grayson C, Faerman B, Koufos O, Mailloux RJ. Fatty acid oxidation drives mitochondrial hydrogen peroxide production by α-ketoglutarate dehydrogenase. J Biol Chem 2024; 300:107159. [PMID: 38479602 PMCID: PMC10997840 DOI: 10.1016/j.jbc.2024.107159] [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: 12/27/2023] [Revised: 02/29/2024] [Accepted: 03/06/2024] [Indexed: 04/07/2024] Open
Abstract
In the present study, we examined the mitochondrial hydrogen peroxide (mH2O2) generating capacity of α-ketoglutarate dehydrogenase (KGDH) and compared it to components of the electron transport chain using liver mitochondria isolated from male and female C57BL6N mice. We show for the first time there are some sex dimorphisms in the production of mH2O2 by electron transport chain complexes I and III when mitochondria are fueled with different substrates. However, in our investigations into these sex effects, we made the unexpected and compelling discovery that 1) KGDH serves as a major mH2O2 supplier in male and female liver mitochondria and 2) KGDH can form mH2O2 when liver mitochondria are energized with fatty acids but only when malate is used to prime the Krebs cycle. Surprisingly, 2-keto-3-methylvaleric acid (KMV), a site-specific inhibitor for KGDH, nearly abolished mH2O2 generation in both male and female liver mitochondria oxidizing palmitoyl-carnitine. KMV inhibited mH2O2 production in liver mitochondria from male and female mice oxidizing myristoyl-, octanoyl-, or butyryl-carnitine as well. S1QEL 1.1 (S1) and S3QEL 2 (S3), compounds that inhibit reactive oxygen species generation by complexes I and III, respectively, without interfering with OxPhos and respiration, had a negligible effect on the rate of mH2O2 production when pyruvate or acyl-carnitines were used as fuels. However, inclusion of KMV in reaction mixtures containing S1 and/or S3 almost abolished mH2O2 generation. Together, our findings suggest KGDH is the main mH2O2 generator in liver mitochondria, even when fatty acids are used as fuel.
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Affiliation(s)
- Cathryn Grayson
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada
| | - Ben Faerman
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada
| | - Olivia Koufos
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada
| | - Ryan J Mailloux
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Quebec, Canada.
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9
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Kumar S, Shenoy S, Swamy RS, Ravichandiran V, Kumar N. Fluoride-Induced Mitochondrial Dysfunction and Approaches for Its Intervention. Biol Trace Elem Res 2024; 202:835-849. [PMID: 37300595 DOI: 10.1007/s12011-023-03720-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 05/28/2023] [Indexed: 06/12/2023]
Abstract
Fluoride is present everywhere in nature. The primary way that individuals are exposed to fluoride is by drinking water. It's interesting to note that while low fluoride levels are good for bone and tooth growth, prolonged fluoride exposure is bad for human health. Additionally, preclinical studies link oxidative stress, inflammation, and programmed cell death to fluoride toxicity. Moreover, mitochondria play a crucial role in the production of reactive oxygen species (ROS). On the other hand, little is known about fluoride's impact on mitophagy, biogenesis, and mitochondrial dynamics. These actions control the growth, composition, and organisation of mitochondria, and the purification of mitochondrial DNA helps to inhibit the production of reactive oxygen species and the release of cytochrome c, which enables cells to survive the effects of fluoride poisoning. In this review, we discuss the different pathways involved in mitochondrial toxicity and dysfunction induced by fluoride. For therapeutic approaches, we discussed different phytochemical and pharmacological agents which reduce the toxicity of fluoride via maintained by imbalanced cellular processes, mitochondrial dynamics, and scavenging the ROS.
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Affiliation(s)
- Sachindra Kumar
- National Institute of Pharmaceutical Education and Research, Hajipur, Industrial Area Hajipur, Vaishali, 844102, India
| | - Smita Shenoy
- Department of Pharmacology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education (MAHE), Manipal, 576104, India
| | - Ravindra Shantakumar Swamy
- Division of Anatomy, Department of Basic Medical Sciences (DBMS), Manipal Academy of Higher Education (MAHE), Manipal, 576104, India
| | - V Ravichandiran
- National Institute of Pharmaceutical Education and Research, Hajipur, Industrial Area Hajipur, Vaishali, 844102, India
| | - Nitesh Kumar
- National Institute of Pharmaceutical Education and Research, Hajipur, Industrial Area Hajipur, Vaishali, 844102, India.
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10
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Ge J, Ye L, Cheng M, Xu W, Chen Z, Guan F. Preparation of microgels loaded with lycopene/NMN and their protective mechanism against acute liver injury. Food Funct 2024; 15:809-822. [PMID: 38131354 DOI: 10.1039/d3fo03293k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
This study aimed to enhance the stability and bioavailability of lycopene (LYC) and nicotinamide mononucleotide (NMN) by incorporating them into porous microgels after loading LYC into liposomes. The particle size, zeta potential, encapsulation rate (%), scanning electron microscopy images, and stability and release kinetics characteristics in simulating digestion confirmed that the microgels had high LYC and NMN encapsulation rates (99.11% ± 0.12% and 68.98% ± 0.26%, respectively) and good stability and release characteristics. The protective effect and potential mechanism of microgels loaded with LYC and NMN on lipopolysaccharide (LPS)-induced acute liver injury in C57BL/6 mice were investigated by intragastric administration for 28 days prior to LPS exposure. The results showed that the microgels loaded with LYC and NMN significantly ameliorated LPS-induced liver injury and reduced the inflammatory response and oxidative stress. In addition, LYC and NMN can not only act on the Toll-like receptor 4 (TLR4)/MD2 complex but also regulate TLR4-related miRNAs (miR-145a-5p and miR-217-5p) in serum extracellular vesicles, thereby synergistically inhibiting the TLR4/NF-κB signaling pathway. In addition, the microgels loaded with LYC and NMN were able to enrich beneficial bacteria that produced short-chain fatty acids and reduce harmful bacteria. In conclusion, LYC and NMN protected against LPS-induced acute liver injury via inhibition of oxidative stress and inflammation, as well as regulating the gut microbiota.
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Affiliation(s)
- Jian Ge
- College of Life Sciences, China Jiliang University, 258 XueYuan Street, XiaSha Higher Education Zone, Hangzhou, 310018, Zhejiang Province, People's Republic of China.
| | - Luting Ye
- College of Life Sciences, China Jiliang University, 258 XueYuan Street, XiaSha Higher Education Zone, Hangzhou, 310018, Zhejiang Province, People's Republic of China.
| | - Min Cheng
- College of Life Sciences, China Jiliang University, 258 XueYuan Street, XiaSha Higher Education Zone, Hangzhou, 310018, Zhejiang Province, People's Republic of China.
| | - Weijia Xu
- College of Life Sciences, China Jiliang University, 258 XueYuan Street, XiaSha Higher Education Zone, Hangzhou, 310018, Zhejiang Province, People's Republic of China.
| | - Zhaowen Chen
- College of Life Sciences, China Jiliang University, 258 XueYuan Street, XiaSha Higher Education Zone, Hangzhou, 310018, Zhejiang Province, People's Republic of China.
| | - Feng Guan
- College of Life Sciences, China Jiliang University, 258 XueYuan Street, XiaSha Higher Education Zone, Hangzhou, 310018, Zhejiang Province, People's Republic of China.
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11
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Szabo E, Nagy B, Czajlik A, Komlodi T, Ozohanics O, Tretter L, Ambrus A. Mitochondrial Alpha-Keto Acid Dehydrogenase Complexes: Recent Developments on Structure and Function in Health and Disease. Subcell Biochem 2024; 104:295-381. [PMID: 38963492 DOI: 10.1007/978-3-031-58843-3_13] [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] [Indexed: 07/05/2024]
Abstract
The present work delves into the enigmatic world of mitochondrial alpha-keto acid dehydrogenase complexes discussing their metabolic significance, enzymatic operation, moonlighting activities, and pathological relevance with links to underlying structural features. This ubiquitous family of related but diverse multienzyme complexes is involved in carbohydrate metabolism (pyruvate dehydrogenase complex), the citric acid cycle (α-ketoglutarate dehydrogenase complex), and amino acid catabolism (branched-chain α-keto acid dehydrogenase complex, α-ketoadipate dehydrogenase complex); the complexes all function at strategic points and also participate in regulation in these metabolic pathways. These systems are among the largest multienzyme complexes with at times more than 100 protein chains and weights ranging up to ~10 million Daltons. Our chapter offers a wealth of up-to-date information on these multienzyme complexes for a comprehensive understanding of their significance in health and disease.
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Affiliation(s)
- Eszter Szabo
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Balint Nagy
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Andras Czajlik
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Timea Komlodi
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Oliver Ozohanics
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Laszlo Tretter
- Department of Biochemistry, Semmelweis University, Budapest, Hungary
| | - Attila Ambrus
- Department of Biochemistry, Semmelweis University, Budapest, Hungary.
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12
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Zhou Y, Fang C, Yuan L, Guo M, Xu X, Shao A, Zhang A, Zhou D. Redox homeostasis dysregulation in noise-induced hearing loss: oxidative stress and antioxidant treatment. J Otolaryngol Head Neck Surg 2023; 52:78. [PMID: 38082455 PMCID: PMC10714662 DOI: 10.1186/s40463-023-00686-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 12/04/2023] [Indexed: 12/18/2023] Open
Abstract
Noise exposure is an important cause of acquired hearing loss. Studies have found that noise exposure causes dysregulated redox homeostasis in cochlear tissue, which has been recognized as a signature feature of hearing loss. Oxidative stress plays a pivotal role in many diseases via very complex and diverse mechanisms and targets. Reactive oxygen species are products of oxidative stress that exert toxic effects on a variety of physiological activities and are considered significant in noise-induced hearing loss (NIHL). Endogenous cellular antioxidants can directly or indirectly counteract oxidative stress and regulate intracellular redox homeostasis, and exogenous antioxidants can complement and enhance this effect. Therefore, antioxidant therapy is considered a promising direction for NIHL treatment. However, drug experiments have been limited to animal models of NIHL, and these experiments and related observations are difficult to translate in humans; therefore, the mechanisms and true effects of these drugs need to be further analyzed. This review outlines the effects of oxidative stress in NIHL and discusses the main mechanisms and strategies of antioxidant treatment for NIHL.
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Affiliation(s)
- Yuhang Zhou
- Health Management Center, Tongde Hospital of Zhejiang Province, Hangzhou, China
- The First Clinical Medical College, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Chaoyou Fang
- Department of Neurosurgery, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ling Yuan
- Department of Neurosurgery, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Mengchen Guo
- Department of Dermatology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xinyi Xu
- School of Medicine, Ningbo University, Ningbo, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Anke Zhang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Danyang Zhou
- Health Management Center, Tongde Hospital of Zhejiang Province, Hangzhou, China.
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13
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Chalifoux O, Faerman B, Mailloux RJ. Mitochondrial hydrogen peroxide production by pyruvate dehydrogenase and α-ketoglutarate dehydrogenase in oxidative eustress and oxidative distress. J Biol Chem 2023; 299:105399. [PMID: 37898400 PMCID: PMC10692731 DOI: 10.1016/j.jbc.2023.105399] [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: 07/26/2023] [Revised: 10/06/2023] [Accepted: 10/16/2023] [Indexed: 10/30/2023] Open
Abstract
Pyruvate dehydrogenase (PDH) and α-ketoglutarate dehydrogenase (KGDH) are vital entry points for monosaccharides and amino acids into the Krebs cycle and thus integral for mitochondrial bioenergetics. Both complexes produce mitochondrial hydrogen peroxide (mH2O2) and are deactivated by electrophiles. Here, we provide an update on the role of PDH and KGDH in mitochondrial redox balance and their function in facilitating metabolic reprogramming for the propagation of oxidative eustress signals in hepatocytes and how defects in these pathways can cause liver diseases. PDH and KGDH are known to account for ∼45% of the total mH2O2 formed by mitochondria and display rates of production several-fold higher than the canonical source complex I. This mH2O2 can also be formed by reverse electron transfer (RET) in vivo, which has been linked to metabolic dysfunctions that occur in pathogenesis. However, the controlled emission of mH2O2 from PDH and KGDH has been proposed to be fundamental for oxidative eustress signal propagation in several cellular contexts. Modification of PDH and KGDH with protein S-glutathionylation (PSSG) and S-nitrosylation (PSNO) adducts serves as a feedback inhibitor for mH2O2 production in response to glutathione (GSH) pool oxidation. PSSG and PSNO adduct formation also reprogram the Krebs cycle to generate metabolites vital for interorganelle and intercellular signaling. Defects in the redox modification of PDH and KGDH cause the over generation of mH2O2, resulting in oxidative distress and metabolic dysfunction-associated fatty liver disease (MAFLD). In aggregate, PDH and KGDH are essential platforms for emitting and receiving oxidative eustress signals.
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Affiliation(s)
- Olivia Chalifoux
- Faculty of Agricultural and Environmental Sciences, The School of Human Nutrition, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada
| | - Ben Faerman
- Faculty of Agricultural and Environmental Sciences, The School of Human Nutrition, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada
| | - Ryan J Mailloux
- Faculty of Agricultural and Environmental Sciences, The School of Human Nutrition, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada.
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14
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Perpiñán E, Sanchez-Fueyo A, Safinia N. Immunoregulation: the interplay between metabolism and redox homeostasis. FRONTIERS IN TRANSPLANTATION 2023; 2:1283275. [PMID: 38993920 PMCID: PMC11235320 DOI: 10.3389/frtra.2023.1283275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/13/2023] [Indexed: 07/13/2024]
Abstract
Regulatory T cells are fundamental for the induction and maintenance of immune homeostasis, with their dysfunction resulting in uncontrolled immune responses and tissue destruction predisposing to autoimmunity, transplant rejection and several inflammatory and metabolic disorders. Recent discoveries have demonstrated that metabolic processes and mitochondrial function are critical for the appropriate functioning of these cells in health, with their metabolic adaptation, influenced by microenvironmental factors, seen in several pathological processes. Upon activation regulatory T cells rearrange their oxidation-reduction (redox) system, which in turn supports their metabolic reprogramming, adding a layer of complexity to our understanding of cellular metabolism. Here we review the literature surrounding redox homeostasis and metabolism of regulatory T cells to highlight new mechanistic insights of these interlinked pathways in immune regulation.
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Affiliation(s)
| | | | - N. Safinia
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, Institute of Liver Studies, James Black Centre, King’s College London, London, United Kingdom
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15
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Okoye CN, Koren SA, Wojtovich AP. Mitochondrial complex I ROS production and redox signaling in hypoxia. Redox Biol 2023; 67:102926. [PMID: 37871533 PMCID: PMC10598411 DOI: 10.1016/j.redox.2023.102926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 10/25/2023] Open
Abstract
Mitochondria are a main source of cellular energy. Oxidative phosphorylation (OXPHOS) is the major process of aerobic respiration. Enzyme complexes of the electron transport chain (ETC) pump protons to generate a protonmotive force (Δp) that drives OXPHOS. Complex I is an electron entry point into the ETC. Complex I oxidizes nicotinamide adenine dinucleotide (NADH) and transfers electrons to ubiquinone in a reaction coupled with proton pumping. Complex I also produces reactive oxygen species (ROS) under various conditions. The enzymatic activities of complex I can be regulated by metabolic conditions and serves as a regulatory node of the ETC. Complex I ROS plays diverse roles in cell metabolism ranging from physiologic to pathologic conditions. Progress in our understanding indicates that ROS release from complex I serves important signaling functions. Increasing evidence suggests that complex I ROS is important in signaling a mismatch in energy production and demand. In this article, we review the role of ROS from complex I in sensing acute hypoxia.
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Affiliation(s)
- Chidozie N Okoye
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Shon A Koren
- Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA
| | - Andrew P Wojtovich
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA; Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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16
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Grayson C, Mailloux RJ. Coenzyme Q 10 and nicotinamide nucleotide transhydrogenase: Sentinels for mitochondrial hydrogen peroxide signaling. Free Radic Biol Med 2023; 208:260-271. [PMID: 37573896 DOI: 10.1016/j.freeradbiomed.2023.08.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/21/2023] [Accepted: 08/08/2023] [Indexed: 08/15/2023]
Abstract
Mitochondria use hydrogen peroxide (H2O2) as a mitokine for cell communication. H2O2 output for signaling depends on its rate of production and degradation, both of which are strongly affected by the redox state of the coenzyme Q10 (CoQ) pool and NADPH availability. Here, we propose the CoQ pool and nicotinamide nucleotide transhydrogenase (NNT) have evolved to be central modalities for mitochondrial H2O2 signaling. Both factors play opposing yet equally important roles in dictating H2O2 availability because they are connected to one another by two central parameters in bioenergetics: electron supply and Δp. The CoQ pool is the central point of convergence for electrons from various dehydrogenases and the electron transport chain (ETC). The increase in Δp creates a significant amount of protonic backpressure on mitochondria to promote H2O2 genesis through CoQ pool reduction. These same factors also drive the activity of NNT, which uses electrons and the Δp to eliminate H2O2. In this way, electron supply and the magnitude of the Δp manifests as a redox connection between the two sentinels, CoQ and NNT, which serve as opposing yet equally important forces required for budgeting H2O2. Taken together, CoQ and NNT are sentinels linked through mitochondrial bioenergetics to manage H2O2 availability for interorganelle and intercellular redox signaling.
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Affiliation(s)
- Cathryn Grayson
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada
| | - Ryan J Mailloux
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Ste.-Anne-de-Bellevue, Quebec, Canada.
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17
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Napolitano G, Fasciolo G, Muscari Tomajoli MT, Venditti P. Changes in the Mitochondria in the Aging Process-Can α-Tocopherol Affect Them? Int J Mol Sci 2023; 24:12453. [PMID: 37569829 PMCID: PMC10419829 DOI: 10.3390/ijms241512453] [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: 06/30/2023] [Revised: 07/28/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Aerobic organisms use molecular oxygen in several reactions, including those in which the oxidation of substrate molecules is coupled to oxygen reduction to produce large amounts of metabolic energy. The utilization of oxygen is associated with the production of ROS, which can damage biological macromolecules but also act as signaling molecules, regulating numerous cellular processes. Mitochondria are the cellular sites where most of the metabolic energy is produced and perform numerous physiological functions by acting as regulatory hubs of cellular metabolism. They retain the remnants of their bacterial ancestors, including an independent genome that encodes part of their protein equipment; they have an accurate quality control system; and control of cellular functions also depends on communication with the nucleus. During aging, mitochondria can undergo dysfunctions, some of which are mediated by ROS. In this review, after a description of how aging affects the mitochondrial quality and quality control system and the involvement of mitochondria in inflammation, we report information on how vitamin E, the main fat-soluble antioxidant, can protect mitochondria from age-related changes. The information in this regard is scarce and limited to some tissues and some aspects of mitochondrial alterations in aging. Improving knowledge of the effects of vitamin E on aging is essential to defining an optimal strategy for healthy aging.
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Affiliation(s)
- Gaetana Napolitano
- Department of Science and Technology, University of Naples Parthenope, Via Acton n. 38, I-80133 Naples, Italy; (G.N.); (M.T.M.T.)
| | - Gianluca Fasciolo
- Department of Biology, University of Naples ‘Napoli Federico II’, Complesso Universitario di Monte Sant’Angelo, Via Cinthia, I-80126 Naples, Italy;
| | - Maria Teresa Muscari Tomajoli
- Department of Science and Technology, University of Naples Parthenope, Via Acton n. 38, I-80133 Naples, Italy; (G.N.); (M.T.M.T.)
| | - Paola Venditti
- Department of Biology, University of Naples ‘Napoli Federico II’, Complesso Universitario di Monte Sant’Angelo, Via Cinthia, I-80126 Naples, Italy;
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18
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Goicoechea L, Conde de la Rosa L, Torres S, García-Ruiz C, Fernández-Checa JC. Mitochondrial cholesterol: Metabolism and impact on redox biology and disease. Redox Biol 2023; 61:102643. [PMID: 36857930 PMCID: PMC9989693 DOI: 10.1016/j.redox.2023.102643] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/10/2023] [Accepted: 02/22/2023] [Indexed: 02/26/2023] Open
Abstract
Cholesterol is a crucial component of membrane bilayers by regulating their structural and functional properties. Cholesterol traffics to different cellular compartments including mitochondria, whose cholesterol content is low compared to other cell membranes. Despite the limited availability of cholesterol in the inner mitochondrial membrane (IMM), the metabolism of cholesterol in the IMM plays important physiological roles, acting as the precursor for the synthesis of steroid hormones and neurosteroids in steroidogenic tissues and specific neurons, respectively, or the synthesis of bile acids through an alternative pathway in the liver. Accumulation of cholesterol in mitochondria above physiological levels has a negative impact on mitochondrial function through several mechanisms, including the limitation of crucial antioxidant defenses, such as the glutathione redox cycle, increased generation of reactive oxygen species and consequent oxidative modification of cardiolipin, and defective assembly of respiratory supercomplexes. These adverse consequences of increased mitochondrial cholesterol trafficking trigger the onset of oxidative stress and cell death, and, ultimately, contribute to the development of diverse diseases, including metabolic liver diseases (i.e. fatty liver disease and liver cancer), as well as lysosomal disorders (i.e. Niemann-Pick type C disease) and neurodegenerative diseases (i.e. Alzheimer's disease). In this review, we summarize the metabolism and regulation of mitochondrial cholesterol and its potential impact on liver and neurodegenerative diseases.
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Affiliation(s)
- Leire Goicoechea
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain; Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red (CIBEREHD), Barcelona, Spain
| | - Laura Conde de la Rosa
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain; Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red (CIBEREHD), Barcelona, Spain
| | - Sandra Torres
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain; Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red (CIBEREHD), Barcelona, Spain
| | - Carmen García-Ruiz
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain; Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red (CIBEREHD), Barcelona, Spain; Research Center for ALPD, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
| | - José C Fernández-Checa
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, Barcelona, Spain; Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red (CIBEREHD), Barcelona, Spain; Research Center for ALPD, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
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19
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Baek JI, Kim YR, Lee KY, Kim UK. Mitochondrial redox system: A key target of antioxidant therapy to prevent acquired sensorineural hearing loss. Front Pharmacol 2023; 14:1176881. [PMID: 37063286 PMCID: PMC10102650 DOI: 10.3389/fphar.2023.1176881] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
Noise (noise-induced hearing loss), and ototoxic drugs (drug-induced ototoxicity), and aging (age-related hearing loss) are the major environmental factors that lead to acquired sensorineural hearing loss. So far, there have been numerous efforts to develop protective or therapeutic agents for acquired hearing loss by investigating the pathological mechanisms of each types of hearing loss, especially in cochlear hair cells and auditory nerves. Although there is still a lack of information on the underlying mechanisms of redox homeostasis and molecular redox networks in hair cells, an imbalance in mitochondrial reactive oxygen species (ROS) levels that enhance oxidative stress has been suggested as a key pathological factor eventually causing acquired sensorineural hearing loss. Thus, various types of antioxidants have been investigated for their abilities to support auditory cells in maintenance of the hearing function against ototoxic stimuli. In this review, we will discuss the scientific possibility of developing drugs that target particular key elements of the mitochondrial redox network in prevention or treatment of noise- and ototoxic drug-induced hearing loss.
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Affiliation(s)
- Jeong-In Baek
- Department of Companion Animal Health, College of Rehabilitation and Health, Daegu Haany University, Gyeongsan, Republic of Korea
| | - Ye-Ri Kim
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
- Advanced Bio-Resource Research Center, Kyungpook National University, Daegu, Republic of Korea
| | - Kyu-Yup Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Un-Kyung Kim
- Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
- School of Life Sciences, KNU Creative BioResearch Group (BK21 Plus Project), Kyungpook National University, Daegu, Republic of Korea
- *Correspondence: Un-Kyung Kim,
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20
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Barrett JN, Barrett EF, Rajguru SM. Mitochondrial responses to intracellular Ca 2+ release following infrared stimulation. J Neurophysiol 2023; 129:700-716. [PMID: 36752512 PMCID: PMC10026987 DOI: 10.1152/jn.00293.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Many studies of Ca2+ effects on mitochondrial respiration in intact cells have used electrical and/or chemical stimulation to elevate intracellular [Ca2+], and have reported increases in [NADH] and increased ADP/ATP ratios as dominant controllers of respiration. This study tested a different form of stimulation: brief temperature increases produced by pulses of infrared light (IR, 1,863 nm, 8-10°C for ∼5 s). Fluorescence imaging techniques applied to single PC-12 cells in low µM extracellular [Ca2+] revealed IR stimulation-induced increases in both cytosolic (fluo5F) and mitochondrial (rhod2) [Ca2+]. IR stimulation increased O2 consumption (porphyrin fluorescence), and produced an alkaline shift in mitochondrial matrix pH (Snarf1), indicating activation of the electron transport chain (ETC). The increase in O2 consumption persisted in oligomycin, and began during a decrease in NADH, suggesting that the initial increase in ETC activity was not driven by increased ATP synthase activity or an increased fuel supply to ETC complex I. Imaging with two potentiometric dyes [tetramethyl rhodamine methyl ester (TMRM) and R123] indicated a depolarizing shift in ΔΨm that persisted in high [K+] medium. High-resolution fluorescence imaging disclosed large, reversible mitochondrial depolarizations that were inhibited by cyclosporin A (CSA), consistent with the opening of transient mitochondrial permeability transition pores. IR stimulation also produced a Ca2+-dependent increase in superoxide production (MitoSox) that was not inhibited by CSA, indicating that the increase in superoxide did not require transition pore opening. Thus, the intracellular Ca2+ release that follows pulses of infrared light offers new insights into Ca2+-dependent processes controlling respiration and reactive oxygen species in intact cells.NEW & NOTEWORTHY Pulses of infrared light (IR) provide a novel method for rapidly transferring Ca2+ from the endoplasmic reticulum to mitochondria in intact cells. In PC12 cells the resulting ETC activation was not driven by increased ATP synthase activity or NADH. IR stimulation produced a Ca2+-dependent, reversible depolarization of ΔΨm that was partially blocked by cyclosporin A, and a Ca2+-dependent increase in superoxide that did not require transition pore opening.
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Affiliation(s)
- John N Barrett
- Department of Physiology and Biophysics, University of Miami, Florida, United States
- Neuroscience Program, University of Miami, Florida, United States
| | - Ellen F Barrett
- Department of Physiology and Biophysics, University of Miami, Florida, United States
- Neuroscience Program, University of Miami, Florida, United States
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami, Florida, United States
- Department of Otolaryngology, University of Miami, Florida, United States
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21
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Hung CH, Tsai MH, Wang PS, Liang FW, Hsu CY, Lee KW, Fong YO, Han DS, Lee CH, Lai CL, Chen CC. Oxidative stress involves phenotype modulation of morbid soreness symptoms in fibromyalgia. RMD Open 2023; 9:rmdopen-2022-002741. [PMID: 36918228 PMCID: PMC10016302 DOI: 10.1136/rmdopen-2022-002741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 02/27/2023] [Indexed: 03/16/2023] Open
Abstract
OBJECTIVES Muscle soreness occurs after exercise and also in musculoskeletal diseases, such as fibromyalgia (FM). However, the nosography and pathoetiology of morbid soreness in FM remain unknown. This study aimed to investigate the morbid soreness of FM, evaluate its therapeutic responses and probe its pathophysiology with metabolomics profiling. METHODS Patients with newly diagnosed FM were prospectively recruited and completed self-report questionnaires pertaining to musculoskeletal symptoms. The phenotypes and metabotypes were assessed with variance, classification and correlation analyses. RESULTS Fifty-one patients and 41 healthy controls were included. Soreness symptoms were prevalent in FM individuals (92.2%). In terms of manifestations and metabolomic features, phenotypes diverged between patients with mixed pain and soreness symptoms (FM-PS) and those with pain dominant symptoms. Conventional treatment for FM did not ameliorate soreness severity despite its efficacy on pain. Moreover, despite the salient therapeutic efficacy on pain relief in FM-PS cases, conventional treatment did not improve their general disease severity. Metabolomics analyses suggested oxidative metabolism dysregulation in FM, and high malondialdehyde level indicated excessive oxidative stress in FM individuals as compared with controls (p=0.009). Contrary to exercise-induced soreness, lactate levels were significantly lower in FM individuals than controls, especially in FM-PS. Moreover, FM-PS cases exclusively featured increased malondialdehyde level (p=0.008) and a correlative trend between malondialdehyde expression and soreness intensity (r=0.337, p=0.086). CONCLUSIONS Morbid soreness symptoms were prevalent in FM, with the presentation and therapeutic responses different from FM pain conditions. Oxidative stress rather than lactate accumulation involved phenotype modulation of the morbid soreness in FM. TRIAL REGISTRATION NUMBER NCT04832100.
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Affiliation(s)
- Chih-Hsien Hung
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ming-Hsien Tsai
- Department of Child Care, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Po-Sheng Wang
- Department of Nutrition and Health Sciences, Fooyin University, Kaohsiung, Taiwan
| | - Fu-Wen Liang
- Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Center for Big Data Research, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chung-Yao Hsu
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Kuo-Wei Lee
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Department of Neurology, Kaohsiung Municipal Hsiao Kang Hospital, Kaohsiung, Taiwan
| | - Yi-On Fong
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Der-Sheng Han
- Department of Physical Medicine and Rehabilitation, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Physical Medicine and Rehabilitation, National Taiwan UniversityHospital, Bei-Hu Branch, Taipei, Taiwan
| | - Cheng-Han Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chiou-Lian Lai
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan .,School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan .,Taiwan Mouse Clinic - National Comprehensive Mouse Phenotyping and DrugTesting Center, Academia Sinica, Taipei, Taiwan
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22
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Lipoamide dehydrogenase (LADH) deficiency: medical perspectives of the structural and functional characterization of LADH and its pathogenic variants. Biol Futur 2023:10.1007/s42977-023-00155-6. [PMID: 36842090 DOI: 10.1007/s42977-023-00155-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/08/2023] [Indexed: 02/27/2023]
Abstract
(Dihydro)lipoamide dehydrogenase (LADH) deficiency is an autosomal recessive genetic metabolic disorder. It generally presents with an onset in the neonatal age and premature death. The clinical picture usually involves metabolic decompensation and lactic acidosis that lead to neurological, cardiological, and/or hepatological outcomes. Severity of the disease is due to the fact that LADH is a common E3 subunit to the pyruvate, alpha-ketoglutarate, alpha-ketoadipate, and branched-chain alpha-keto acid dehydrogenase complexes and is also part of the glycine cleavage system; hence, a loss in LADH activity adversely affects several central metabolic pathways simultaneously. The severe clinical manifestations, however, often do not parallel the LADH activity loss, which implies the existence of auxiliary pathological pathways; stimulated reactive oxygen species (ROS) production as well as dissociation from the relevant multienzyme complexes proved to be auxiliary exacerbating pathomechanisms for selected disease-causing LADH mutations. This review provides an overview on the therapeutic challenges of inherited metabolic diseases, structural and functional characteristics of the mitochondrial alpha-keto acid dehydrogenase complexes, molecular pathogenesis and structural basis of LADH deficiency, and relevant potential future medical perspectives.
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23
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Oh S, Jo S, Bajzikova M, Kim HS, Dao TTP, Rohlena J, Kim JM, Neuzil J, Park S. Non-bioenergetic roles of mitochondrial GPD2 promote tumor progression. Theranostics 2023; 13:438-457. [PMID: 36632231 PMCID: PMC9830446 DOI: 10.7150/thno.75973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 11/19/2022] [Indexed: 12/23/2022] Open
Abstract
Rationale: Despite growing evidence for mitochondria's involvement in cancer, the roles of specific metabolic components outside the respiratory complex have been little explored. We conducted metabolomic studies on mitochondrial DNA (mtDNA)-deficient (ρ0) cancer cells with lower proliferation rates to clarify the undefined roles of mitochondria in cancer growth. Methods and results: Despite extensive metabolic downregulation, ρ0 cells exhibited high glycerol-3-phosphate (G3P) level, due to low activity of mitochondrial glycerol-3-phosphate dehydrogenase (GPD2). Knockout (KO) of GPD2 resulted in cell growth suppression as well as inhibition of tumor progression in vivo. Surprisingly, this was unrelated to the conventional bioenergetic function of GPD2. Instead, multi-omics results suggested major changes in ether lipid metabolism, for which GPD2 provides dihydroxyacetone phosphate (DHAP) in ether lipid biosynthesis. GPD2 KO cells exhibited significantly lower ether lipid level, and their slower growth was rescued by supplementation of a DHAP precursor or ether lipids. Mechanistically, ether lipid metabolism was associated with Akt pathway, and the downregulation of Akt/mTORC1 pathway due to GPD2 KO was rescued by DHAP supplementation. Conclusion: Overall, the GPD2-ether lipid-Akt axis is newly described for the control of cancer growth. DHAP supply, a non-bioenergetic process, may constitute an important role of mitochondria in cancer.
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Affiliation(s)
- Sehyun Oh
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul 08826, Korea
| | - Sihyang Jo
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul 08826, Korea
| | - Martina Bajzikova
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld, Australia
| | - Han Sun Kim
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul 08826, Korea
| | - Thien T. P. Dao
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul 08826, Korea
| | - Jakub Rohlena
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Jin-Mo Kim
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul 08826, Korea
| | - Jiri Neuzil
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld, Australia.,Institute of Biotechnology, Czech Academy of Sciences, Prague-West, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic.,✉ Corresponding authors: Sunghyouk Park, Natural Product Research Institute, College of Pharmacy, Seoul National University, Gwanak-Ro 1, Gwanak-gu, Seoul 08826, Republic of Korea, Tel: +82-2-880-7831; Fax: +82-2-880-7831; E-mail: ; Jiri Neuzil, School of Pharmacy and Medical Science, Griffith University, 1 Parklands Dr, Southport, Qld 4215, Australia, Tel: +61-(0)7-5552-9109; Fax: +61-(0)7-5552-9109; E-mail: or
| | - Sunghyouk Park
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul 08826, Korea.,✉ Corresponding authors: Sunghyouk Park, Natural Product Research Institute, College of Pharmacy, Seoul National University, Gwanak-Ro 1, Gwanak-gu, Seoul 08826, Republic of Korea, Tel: +82-2-880-7831; Fax: +82-2-880-7831; E-mail: ; Jiri Neuzil, School of Pharmacy and Medical Science, Griffith University, 1 Parklands Dr, Southport, Qld 4215, Australia, Tel: +61-(0)7-5552-9109; Fax: +61-(0)7-5552-9109; E-mail: or
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Regulation of Mitochondrial Hydrogen Peroxide Availability by Protein S-glutathionylation. Cells 2022; 12:cells12010107. [PMID: 36611901 PMCID: PMC9818751 DOI: 10.3390/cells12010107] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND It has been four decades since protein S-glutathionylation was proposed to serve as a regulator of cell metabolism. Since then, this redox-sensitive covalent modification has been identified as a cell-wide signaling platform required for embryonic development and regulation of many physiological functions. SCOPE OF THE REVIEW Mitochondria use hydrogen peroxide (H2O2) as a second messenger, but its availability must be controlled to prevent oxidative distress and promote changes in cell behavior in response to stimuli. Experimental data favor the function of protein S-glutathionylation as a feedback loop for the inhibition of mitochondrial H2O2 production. MAJOR CONCLUSIONS The glutathione pool redox state is linked to the availability of H2O2, making glutathionylation an ideal mechanism for preventing oxidative distress whilst playing a part in desensitizing mitochondrial redox signals. GENERAL SIGNIFICANCE The biological significance of glutathionylation is rooted in redox status communication. The present review critically evaluates the experimental evidence supporting its role in negating mitochondrial H2O2 production for cell signaling and prevention of electrophilic stress.
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Yu T, Zhang Y, Zheng WQ, Wu S, Li G, Zhang Y, Li N, Yao R, Fang P, Wang J, Zhou XL. Selective degradation of tRNASer(AGY) is the primary driver for mitochondrial seryl-tRNA synthetase-related disease. Nucleic Acids Res 2022; 50:11755-11774. [PMID: 36350636 PMCID: PMC9723649 DOI: 10.1093/nar/gkac1028] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/13/2022] [Accepted: 10/21/2022] [Indexed: 11/11/2022] Open
Abstract
Mitochondrial translation is of high significance for cellular energy homeostasis. Aminoacyl-tRNA synthetases (aaRSs) are crucial translational components. Mitochondrial aaRS variants cause various human diseases. However, the pathogenesis of the vast majority of these diseases remains unknown. Here, we identified two novel SARS2 (encoding mitochondrial seryl-tRNA synthetase) variants that cause a multisystem disorder. c.654-14T > A mutation induced mRNA mis-splicing, generating a peptide insertion in the active site; c.1519dupC swapped a critical tRNA-binding motif in the C-terminus due to stop codon readthrough. Both mutants exhibited severely diminished tRNA binding and aminoacylation capacities. A marked reduction in mitochondrial tRNASer(AGY) was observed due to RNA degradation in patient-derived induced pluripotent stem cells (iPSCs), causing impaired translation and comprehensive mitochondrial function deficiencies. These impairments were efficiently rescued by wild-type SARS2 overexpression. Either mutation caused early embryonic fatality in mice. Heterozygous mice displayed reduced muscle tissue-specific levels of tRNASers. Our findings elucidated the biochemical and cellular consequences of impaired translation mediated by SARS2, suggesting that reduced abundance of tRNASer(AGY) is a key determinant for development of SARS2-related diseases.
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Affiliation(s)
| | | | - Wen-Qiang Zheng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Siqi Wu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Guoqiang Li
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Key Laboratory of Clinical Molecular Diagnostics for Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dong Fang Road, Shanghai 200127, China
| | - Yong Zhang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Niu Li
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Key Laboratory of Clinical Molecular Diagnostics for Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dong Fang Road, Shanghai 200127, China
| | - Ruen Yao
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Key Laboratory of Clinical Molecular Diagnostics for Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dong Fang Road, Shanghai 200127, China
| | - Pengfei Fang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Jian Wang
- Correspondence may also be addressed to Jian Wang. Tel: +86 21 3808 7371;
| | - Xiao-Long Zhou
- To whom correspondence should be addressed. Tel: +86 21 5492 1247; Fax: +86 21 5492 1011;
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26
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Zelentsova AS, Deykin AV, Soldatov VO, Ulezko AA, Borisova AY, Belyaeva VS, Skorkina MY, Angelova PR. P2X7 Receptor and Purinergic Signaling: Orchestrating Mitochondrial Dysfunction in Neurodegenerative Diseases. eNeuro 2022; 9:ENEURO.0092-22.2022. [PMID: 36376084 PMCID: PMC9665882 DOI: 10.1523/eneuro.0092-22.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/14/2022] [Accepted: 08/09/2022] [Indexed: 11/15/2022] Open
Abstract
Mitochondrial dysfunction is one of the basic hallmarks of cellular pathology in neurodegenerative diseases. Since the metabolic activity of neurons is highly dependent on energy supply, nerve cells are especially vulnerable to impaired mitochondrial function. Besides providing oxidative phosphorylation, mitochondria are also involved in controlling levels of second messengers such as Ca2+ ions and reactive oxygen species (ROS). Interestingly, the critical role of mitochondria as producers of ROS is closely related to P2XR purinergic receptors, the activity of which is modulated by free radicals. Here, we review the relationships between the purinergic signaling system and affected mitochondrial function. Purinergic signaling regulates numerous vital biological processes in the CNS. The two main purines, ATP and adenosine, act as excitatory and inhibitory neurotransmitters, respectively. Current evidence suggests that purinergic signaling best explains how neuronal activity is related to neuronal electrical activity and energy homeostasis, especially in the development of Alzheimer's and Parkinson's diseases. In this review, we focus on the mechanisms underlying the involvement of the P2RX7 purinoreceptor in triggering mitochondrial dysfunction during the development of neurodegenerative disorders. We also summarize various avenues by which the purine signaling pathway may trigger metabolic dysfunction contributing to neuronal death and the inflammatory activation of glial cells. Finally, we discuss the potential role of the purinergic system in the search for new therapeutic approaches to treat neurodegenerative diseases.
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27
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Hansen GE, Gibson GE. The α-Ketoglutarate Dehydrogenase Complex as a Hub of Plasticity in Neurodegeneration and Regeneration. Int J Mol Sci 2022; 23:12403. [PMID: 36293260 PMCID: PMC9603878 DOI: 10.3390/ijms232012403] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/06/2022] [Accepted: 10/11/2022] [Indexed: 07/30/2023] Open
Abstract
Abnormal glucose metabolism is central to neurodegeneration, and considerable evidence suggests that abnormalities in key enzymes of the tricarboxylic acid (TCA) cycle underlie the metabolic deficits. Significant recent advances in the role of metabolism in cancer provide new insight that facilitates our understanding of the role of metabolism in neurodegeneration. Research indicates that the rate-limiting step of the TCA cycle, the α-ketoglutarate dehydrogenase complex (KGDHC) and its substrate alpha ketoglutarate (KG), serve as a signaling hub that regulates multiple cellular processes: (1) is the rate-limiting step of the TCA cycle, (2) is sensitive to reactive oxygen species (ROS) and produces ROS, (3) determines whether KG is used for energy or synthesis of compounds to support growth, (4) regulates the cellular responses to hypoxia, (5) controls the post-translational modification of hundreds of cell proteins in the mitochondria, cytosol, and nucleus through succinylation, (6) controls critical aspects of transcription, (7) modulates protein signaling within cells, and (8) modulates cellular calcium. The primary focus of this review is to understand how reductions in KGDHC are translated to pathologically important changes that underlie both neurodegeneration and cancer. An understanding of each role is necessary to develop new therapeutic strategies to treat neurodegenerative disease.
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Affiliation(s)
- Grace E. Hansen
- Department of Biology, University of Massachusetts, Lowell, MA 01852, USA
| | - Gary E. Gibson
- Weill Cornell Medicine, Brain and Mind Research Institute, Burke Neurological Institute, White Plains, NY 10605, USA
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28
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Bettendorff L. Reduced Nucleotides, Thiols and O 2 in Cellular Redox Balance: A Biochemist's View. Antioxidants (Basel) 2022; 11:1877. [PMID: 36290600 PMCID: PMC9598635 DOI: 10.3390/antiox11101877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 07/30/2023] Open
Abstract
In the present review, which is aimed at researchers, teachers and students in life sciences, we try to show how the physicochemical properties of the elements and molecules define the concept of redox balance. Living organism are open systems traversed by fluxes of energy and matter. During catabolic oxidative metabolism, matter-mostly hydrogenated organic molecules-is oxidized and ultimately released as CO2. Electrons are passed over to coupling molecules, such as NAD+ and FAD, whose reduced forms serve as electrons donors in anabolic reactions. Early photosynthetic activity led to the accumulation of O2 and the transformation of the reduction to an oxidizing atmosphere, favoring the development of oxidative metabolism in living organisms. We focus on the specific properties of O2 that provide the chemical energy for the combustion reactions occurring in living cells. We explain the concepts of redox potential and redox balance in complex systems such as living cells, we present the main redox couples involved in cellular redox balance and we discuss the chemical properties underlying their cellular roles and, in particular, their antioxidant properties in the defense against reactive oxygen species (ROS). Finally, we try to provide an integrative view emphasizing the interplay between metabolism, oxidative stress and metabolic compartmentation in mammalian cells.
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Affiliation(s)
- Lucien Bettendorff
- Laboratory of Neurophysiology, GIGA Neurosciences, University of Liège, 4000 Liège, Belgium
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29
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Gao X, Fu Y, Sun S, Gu T, Li Y, Sun T, Li H, Du W, Suo C, Li C, Gao Y, Meng Y, Ni Y, Yang S, Lan T, Sai S, Li J, Yu K, Wang P, Ding C. Cryptococcal Hsf3 controls intramitochondrial ROS homeostasis by regulating the respiratory process. Nat Commun 2022; 13:5407. [PMID: 36109512 PMCID: PMC9477856 DOI: 10.1038/s41467-022-33168-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 09/06/2022] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial quality control prevents accumulation of intramitochondrial-derived reactive oxygen species (mtROS), thereby protecting cells against DNA damage, genome instability, and programmed cell death. However, underlying mechanisms are incompletely understood, particularly in fungal species. Here, we show that Cryptococcus neoformans heat shock factor 3 (CnHsf3) exhibits an atypical function in regulating mtROS independent of the unfolded protein response. CnHsf3 acts in nuclei and mitochondria, and nuclear- and mitochondrial-targeting signals are required for its organelle-specific functions. It represses the expression of genes involved in the tricarboxylic acid cycle while promoting expression of genes involved in electron transfer chain. In addition, CnHsf3 responds to multiple intramitochondrial stresses; this response is mediated by oxidation of the cysteine residue on its DNA binding domain, which enhances DNA binding. Our results reveal a function of HSF proteins in regulating mtROS homeostasis that is independent of the unfolded protein response. Mitochondrial quality control prevents accumulation of intramitochondrial reactive oxygen species (mtROS), thus protecting cells against DNA damage. Here, Gao et al. show that an atypical heat shock factor responds to intramitochondrial stresses and regulates mtROS homeostasis in the pathogenic fungus Cryptococcus neoformans.
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30
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Effect of metformin on intact mitochondria from liver and brain: Concept revisited. Eur J Pharmacol 2022; 931:175177. [DOI: 10.1016/j.ejphar.2022.175177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 07/07/2022] [Accepted: 07/25/2022] [Indexed: 11/18/2022]
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31
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Hughey CC, Puchalska P, Crawford PA. Integrating the contributions of mitochondrial oxidative metabolism to lipotoxicity and inflammation in NAFLD pathogenesis. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159209. [DOI: 10.1016/j.bbalip.2022.159209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/25/2022] [Accepted: 07/27/2022] [Indexed: 11/28/2022]
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32
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Horváth G, Sváb G, Komlódi T, Ravasz D, Kacsó G, Doczi J, Chinopoulos C, Ambrus A, Tretter L. Reverse and Forward Electron Flow-Induced H2O2 Formation Is Decreased in α-Ketoglutarate Dehydrogenase (α-KGDH) Subunit (E2 or E3) Heterozygote Knock Out Animals. Antioxidants (Basel) 2022; 11:antiox11081487. [PMID: 36009207 PMCID: PMC9404749 DOI: 10.3390/antiox11081487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 12/04/2022] Open
Abstract
α-ketoglutarate dehydrogenase complex (KGDHc), or 2-oxoglutarate dehydrogenase complex (OGDHc) is a rate-limiting enzyme in the tricarboxylic acid cycle, that has been identified in neurodegenerative diseases such as in Alzheimer’s disease. The aim of the present study was to establish the role of the KGDHc and its subunits in the bioenergetics and reactive oxygen species (ROS) homeostasis of brain mitochondria. To study the bioenergetic profile of KGDHc, genetically modified mouse strains were used having a heterozygous knock out (KO) either in the dihydrolipoyl succinyltransferase (DLST+/−) or in the dihydrolipoyl dehydrogenase (DLD+/−) subunit. Mitochondrial oxygen consumption, hydrogen peroxide (H2O2) production, and expression of antioxidant enzymes were measured in isolated mouse brain mitochondria. Here, we demonstrate that the ADP-stimulated respiration of mitochondria was partially arrested in the transgenic animals when utilizing α-ketoglutarate (α-KG or 2-OG) as a fuel substrate. Succinate and α-glycerophosphate (α-GP), however, did not show this effect. The H2O2 production in mitochondria energized with α-KG was decreased after inhibiting the adenine nucleotide translocase and Complex I (CI) in the transgenic strains compared to the controls. Similarly, the reverse electron transfer (RET)-evoked H2O2 formation supported by succinate or α-GP were inhibited in mitochondria isolated from the transgenic animals. The decrease of RET-evoked ROS production by DLST+/− or DLD+/− KO-s puts the emphasis of the KGDHc in the pathomechanism of ischemia-reperfusion evoked oxidative stress. Supporting this notion, expression of the antioxidant enzyme glutathione peroxidase was also decreased in the KGDHc transgenic animals suggesting the attenuation of ROS-producing characteristics of KGDHc. These findings confirm the contribution of the KGDHc to the mitochondrial ROS production and in the pathomechanism of ischemia-reperfusion injury.
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33
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Guo Y, Li Q, Xia R, Cai C. Farrerol exhibits inhibitory effects on lung adenocarcinoma cells by activating the mitochondrial apoptotic pathway. J Biochem Mol Toxicol 2022; 36:e23157. [PMID: 35833306 DOI: 10.1002/jbt.23157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 04/11/2022] [Accepted: 07/01/2022] [Indexed: 11/11/2022]
Abstract
Farrerol is an herbal compound extracted from rhododendron. Here, our study is to investigate biological effects of farrerol on lung adenocarcinoma (LAC) cells. Human LAC cell lines and xenograft mouse model were utilized to define the effects of farrerol on tumor growth. Our findings indicated that farrerol significantly reduced LAC cell viability as well as the colony-forming capacity. Flow cytometry analysis demonstrated that farrerol contributed to cell apoptosis and G0/G1 phase cell cycle arrest. Mechanistically, farrerol treatment upregulated proapoptotic molecules (Bak, Bid, cleaved caspase-3 and cleaved caspase-9) and senescence markers (p16 and p2), but downregulated antiapoptosis genes (Bcl-2 and Bcl-XL) and cell cycle-associated genes (CyclinD1 and CDK4); meanwhile, the phosphorylation of retinoblastoma (Rb) protein was attenuated upon pretreatment of LAC cells with farrerol in comparison to untreated control. Further studies indicated that farrerol elevated reactive oxygen species levels, activating mitochondrial apoptotic pathway and causing cell apoptosis. However, exposure to farrerol did not result in significant apoptosis in normal lung epithelial cells, suggesting a tumor-specific effect of farrerol on LAC cells. In animal model, farrerol showed a significant inhibitory effect on LAC xenograft tumor growth. And gene expressions in tumor tissues, as mentioned above, were in line with the in vitro results. Taken together, these results suggested that farrerol caused LAC cell apoptosis by activating mitochondrial apoptotic pathway, whereas farrerol treatment had no notable effect on normal lung epithelial cells. Farrerol might be an effective therapeutic drug for LAC.
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Affiliation(s)
- Yi Guo
- Department of Pneumology, Shanxi Provincial Cancer Hospital, Taiyuan, Shanxi, China
| | - Quan Li
- Department of Oncology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, Hubei, China
| | - Rongmu Xia
- School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Chuanshu Cai
- Department of Radiotherapy, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
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34
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Chang LC, Chiang SK, Chen SE, Hung MC. Targeting 2-oxoglutarate dehydrogenase for cancer treatment. Am J Cancer Res 2022; 12:1436-1455. [PMID: 35530286 PMCID: PMC9077069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023] Open
Abstract
Tricarboxylic acid (TCA) cycle, also called Krebs cycle or citric acid cycle, is an amphoteric pathway, contributing to catabolic degradation and anaplerotic reactions to supply precursors for macromolecule biosynthesis. Oxoglutarate dehydrogenase complex (OGDHc, also called α-ketoglutarate dehydrogenase) a highly regulated enzyme in TCA cycle, converts α-ketoglutarate (αKG) to succinyl-Coenzyme A in accompany with NADH generation for ATP generation through oxidative phosphorylation. The step collaborates with glutaminolysis at an intersectional point to govern αKG levels for energy production, nucleotide and amino acid syntheses, and the resources for macromolecule synthesis in cancer cells with rapid proliferation. Despite being a flavoenzyme susceptible to electron leakage contributing to mitochondrial reactive oxygen species (ROS) production, OGDHc is highly sensitive to peroxides such as HNE (4-hydroxy-2-nonenal) and moreover, its activity mediates the activation of several antioxidant pathways. The characteristics endow OGDHc as a critical redox sensor in mitochondria. Accumulating evidences suggest that dysregulation of OGDHc impairs cellular redox homeostasis and disturbs substrate fluxes, leading to a buildup of oncometabolites along the pathogenesis and development of cancers. In this review, we describe molecular interactions, regulation of OGDHc expression and activity and its relationships with diseases, specifically focusing on cancers. In the end, we discuss the potential of OGDHs as a therapeutic target for cancer treatment.
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Affiliation(s)
- Ling-Chu Chang
- Center for Molecular Medicine, China Medical University Hospital, China Medical UniversityTaichung 404, Taiwan
| | - Shih-Kai Chiang
- Department of Animal Science, National Chung Hsing UniversityTaichung 40227, Taiwan
| | - Shuen-Ei Chen
- Department of Animal Science, National Chung Hsing UniversityTaichung 40227, Taiwan
- The iEGG and Animal Biotechnology Center, National Chung Hsing UniversityTaichung 40227, Taiwan
- Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing UniversityTaiwan
- Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing UniversityTaichung 40227, Taiwan
| | - Mien-Chie Hung
- Center for Molecular Medicine, China Medical University Hospital, China Medical UniversityTaichung 404, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical UniversityTaichung 404, Taiwan
- Deparment of Biotechnology, Asia UniversityTaichung 413, Taiwan
- Research Center for Cancer Biology, China Medical UniversityTaichung 404, Taiwan
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35
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Palmer BF, Clegg DJ. Metabolic Flexibility and Its Impact on Health Outcomes. Mayo Clin Proc 2022; 97:761-776. [PMID: 35287953 DOI: 10.1016/j.mayocp.2022.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/04/2022] [Accepted: 01/12/2022] [Indexed: 02/06/2023]
Abstract
A metabolically flexible state exists when there is a rapid switch between glucose and fatty acids during the transition between the fed and fasting state. This flexibility in fuel choice serves to prevent hyperglycemia following a meal and simultaneously ensures an adequate amount of blood glucose is available for delivery to the brain and exclusively glycolytic tissues during fasting. The modern era is characterized by chronic overnutrition in which a mixture of fuels is delivered to the mitochondria in an unabated manner thereby uncoupling the feast and famine situation. The continuous influx of fuel leads to accumulation of reducing equivalents in the mitochondria and an increase in the mitochondrial membrane potential. These changes create a microenvironment fostering the generation of reactive oxygen species and other metabolites leading to deleterious protein modification, cell injury, and ultimately clinical disease. Insulin resistance may also play a primary role in this deleterious effect. The imbalance between mitochondrial energy delivery and use is made worse with a sedentary lifestyle. Maneuvers that restore energy balance across the mitochondria activate pathways that remove or repair damaged molecules and restore the plasticity characteristic of normal energy metabolism. Readily available strategies to maintain energy balance across the mitochondria include exercise, various forms of caloric restriction, administration of sodium-glucose cotransporter-2 inhibitors, cold exposure, and hypobaric hypoxia.
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Affiliation(s)
- Biff F Palmer
- Department of Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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36
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Mitochondrial Ca 2+ Homeostasis: Emerging Roles and Clinical Significance in Cardiac Remodeling. Int J Mol Sci 2022; 23:ijms23063025. [PMID: 35328444 PMCID: PMC8954803 DOI: 10.3390/ijms23063025] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 01/27/2023] Open
Abstract
Mitochondria are the sites of oxidative metabolism in eukaryotes where the metabolites of sugars, fats, and amino acids are oxidized to harvest energy. Notably, mitochondria store Ca2+ and work in synergy with organelles such as the endoplasmic reticulum and extracellular matrix to control the dynamic balance of Ca2+ concentration in cells. Mitochondria are the vital organelles in heart tissue. Mitochondrial Ca2+ homeostasis is particularly important for maintaining the physiological and pathological mechanisms of the heart. Mitochondrial Ca2+ homeostasis plays a key role in the regulation of cardiac energy metabolism, mechanisms of death, oxygen free radical production, and autophagy. The imbalance of mitochondrial Ca2+ balance is closely associated with cardiac remodeling. The mitochondrial Ca2+ uniporter (mtCU) protein complex is responsible for the uptake and release of mitochondrial Ca2+ and regulation of Ca2+ homeostasis in mitochondria and consequently, in cells. This review summarizes the mechanisms of mitochondrial Ca2+ homeostasis in physiological and pathological cardiac remodeling and the regulatory effects of the mitochondrial calcium regulatory complex on cardiac energy metabolism, cell death, and autophagy, and also provides the theoretical basis for mitochondrial Ca2+ as a novel target for the treatment of cardiovascular diseases.
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37
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Singh V, Ahlawat S, Mohan H, Gill SS, Sharma KK. Balancing reactive oxygen species generation by rebooting gut microbiota. J Appl Microbiol 2022; 132:4112-4129. [PMID: 35199405 DOI: 10.1111/jam.15504] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 11/30/2022]
Abstract
Reactive oxygen species (ROS; free radical form O2 •‾ , superoxide radical; OH• , hydroxyl radical; ROO• , peroxyl; RO• , alkoxyl and non-radical form 1 O2 , singlet oxygen; H2 O2 , hydrogen peroxide) are inevitable companions of aerobic life with crucial role in gut health. But, overwhelming production of ROS can cause serious damage to biomolecules. In this review, we have discussed several sources of ROS production that can be beneficial or dangerous to the human gut. Microorganisms, organelles and enzymes play crucial role in ROS generation, where, NOX1 is the main intestinal enzyme, which produce ROS in the intestine epithelial cells. Previous studies have reported that probiotics play significant role in gut homeostasis by checking the ROS generation, maintaining the antioxidant level, immune system and barrier protection. With current knowledge, we have critically analyzed the available literature and presented the outcome in the form of bubble maps to suggest the probiotics that help in controlling the ROS-specific intestinal diseases, such as inflammatory bowel disease (IBD) and colon cancer. Finally, it has been concluded that rebooting of the gut microbiota with probiotics, postbiotics or fecal microbiota transplantation (FMT) can have crucial implications in the structuring of gut communities for the personalized management of the gastrointestinal (GI) diseases.
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Affiliation(s)
- Vandna Singh
- Department of Medical Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Shruti Ahlawat
- Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India.,Presently at SGT University, Badli Road Chandu, Budhera, Gurugr, Gurgaon, Haryana, India
| | - Hari Mohan
- Department of Medical Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Sarvajeet Singh Gill
- Department of Plant Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Krishna Kant Sharma
- Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
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Over-Reduced State of Mitochondria as a Trigger of "β-Oxidation Shuttle" in Cancer Cells. Cancers (Basel) 2022; 14:cancers14040871. [PMID: 35205619 PMCID: PMC8870273 DOI: 10.3390/cancers14040871] [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: 12/09/2021] [Revised: 01/27/2022] [Accepted: 02/07/2022] [Indexed: 11/17/2022] Open
Abstract
A considerable amount of data have accumulated in the last decade on the pronounced mitochondrial fatty acid oxidation (mFAO) in many types of cancer cells. As a result, mFAO was found to coexist with abnormally activated fatty acid synthesis (FAS) and the mevalonate pathway. Recent studies have demonstrated that overactivated mitochondrial β-oxidation may aggravate the impaired mitochondrial redox state and vice versa. Furthermore, the impaired redox state of cancerous mitochondria can ensure the continuous operation of β-oxidation by disconnecting it from the Krebs cycle and connecting it to the citrate-malate shuttle. This could create a new metabolic state/pathway in cancer cells, which we have called the "β-oxidation-citrate-malate shuttle", or "β-oxidation shuttle" for short, which forces them to proliferate. The calculation of the phosphate/oxygen ratio indicates that it is inefficient as an energy source and must consume significantly more oxygen per mole of ATP produced when combined with acetyl-CoA consuming pathways, such as the FAS and mevalonate pathways. The "β-oxidation shuttle" is an unconventional mFAO, a separate metabolic pathway that has not yet been explored as a source of energy, as well as a source of cataplerosis, leading to biomass accumulation, accelerated oxygen consumption, and, ultimately, a source of proliferation. The role of the "β-oxidation shuttle" and its contribution to redox-altered cancer metabolism provides a new direction for the development of future anticancer strategies. This may represent the metabolic "secret" of cancer underlying hypoxia and genomic instability.
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A “Weird” Mitochondrial Fatty Acid Oxidation as a Metabolic “Secret” of Cancer. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:2339584. [PMID: 35178152 PMCID: PMC8847026 DOI: 10.1155/2022/2339584] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/29/2021] [Indexed: 12/15/2022]
Abstract
Cancer metabolism is an extensively studied field since the discovery of the Warburg effect about 100 years ago and continues to be increasingly intriguing and enigmatic so far. It has become clear that glycolysis is not the only abnormally activated metabolic pathway in the cancer cells, but the same is true for the fatty acid synthesis (FAS) and mevalonate pathway. In the last decade, a lot of data have been accumulated on the pronounced mitochondrial fatty acid oxidation (mFAO) in many types of cancer cells. In this article, we discuss how mFAO can escape normal regulation under certain conditions and be overactivated. Such abnormal activation of mitochondrial β-oxidation can also be combined with mutations in certain enzymes of the Krebs cycle that are common in cancer. If overactivated β-oxidation is combined with other common cancer conditions, such as dysfunctions in the electron transport complexes, and/or hypoxia, this may alter the redox state of the mitochondrial matrix. We propose the idea that the altered mitochondrial redox state and/or inhibited Krebs cycle at certain segments may link mitochondrial β-oxidation to the citrate-malate shuttle instead to the Krebs cycle. We call this abnormal metabolic condition “β-oxidation shuttle”. It is unconventional mFAO, a separate metabolic pathway, unexplored so far as a source of energy, as well as a source of cataplerosis, leading to biomass accumulation, accelerated oxygen consumption, and ultimately a source of proliferation. It is inefficient as an energy source and must consume significantly more oxygen per mole of ATP produced when combined with acetyl-CoA consuming pathways, such as the FAS and mevalonate pathway.
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Mitochondrial Management of Reactive Oxygen Species. Antioxidants (Basel) 2021; 10:antiox10111824. [PMID: 34829696 PMCID: PMC8614740 DOI: 10.3390/antiox10111824] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 01/10/2023] Open
Abstract
Mitochondria in aerobic eukaryotic cells are both the site of energy production and the formation of harmful species, such as radicals and other reactive oxygen species, known as ROS. They contain an efficient antioxidant system, including low-molecular-mass molecules and enzymes that specialize in removing various types of ROS or repairing the oxidative damage of biological molecules. Under normal conditions, ROS production is low, and mitochondria, which are their primary target, are slightly damaged in a similar way to other cellular compartments, since the ROS released by the mitochondria into the cytosol are negligible. As the mitochondrial generation of ROS increases, they can deactivate components of the respiratory chain and enzymes of the Krebs cycle, and mitochondria release a high amount of ROS that damage cellular structures. More recently, the feature of the mitochondrial antioxidant system, which does not specifically deal with intramitochondrial ROS, was discovered. Indeed, the mitochondrial antioxidant system detoxifies exogenous ROS species at the expense of reducing the equivalents generated in mitochondria. Thus, mitochondria are also a sink of ROS. These observations highlight the importance of the mitochondrial antioxidant system, which should be considered in our understanding of ROS-regulated processes. These processes include cell signaling and the progression of metabolic and neurodegenerative disease.
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Ahmad W, Ebert PR. Suppression of a core metabolic enzyme dihydrolipoamide dehydrogenase ( dld) protects against amyloid beta toxicity in C. elegans model of Alzheimer's disease. Genes Dis 2021; 8:849-866. [PMID: 34522713 PMCID: PMC8427249 DOI: 10.1016/j.gendis.2020.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/24/2020] [Accepted: 08/14/2020] [Indexed: 01/24/2023] Open
Abstract
A decrease in energy metabolism is associated with Alzheimer's disease (AD), but it is not known whether the observed decrease exacerbates or protects against the disease. The importance of energy metabolism in AD is reinforced by the observation that variants of dihydrolipoamide dehydrogenase (DLD), is genetically linked to late-onset AD. To determine whether DLD is a suitable therapeutic target, we suppressed the dld-1 gene in Caenorhabditis elegans that express human Aβ peptide in either muscles or neurons. Suppression of the dld-1 gene resulted in significant restoration of vitality and function that had been degraded by Aβ pathology. This included protection of neurons and muscles cells. The observed decrease in proteotoxicity was associated with a decrease in the formation of toxic oligomers rather than a decrease in the abundance of the Aβ peptide. The mitochondrial uncoupler, carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), which like dld-1 gene expression inhibits ATP synthesis, had no significant effect on Aβ toxicity. Proteomics data analysis revealed that beneficial effects after dld-1 suppression could be due to change in energy metabolism and activation of the pathways associated with proteasomal degradation, improved cell signaling and longevity. Thus, some features unique to dld-1 gene suppression are responsible for the therapeutic benefit. By direct genetic intervention, we have shown that acute inhibition of dld-1 gene function may be therapeutically beneficial. This result supports the hypothesis that lowering energy metabolism protects against Aβ pathogenicity and that DLD warrants further investigation as a therapeutic target.
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Affiliation(s)
- Waqar Ahmad
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul R. Ebert
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
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Jurcau A. Insights into the Pathogenesis of Neurodegenerative Diseases: Focus on Mitochondrial Dysfunction and Oxidative Stress. Int J Mol Sci 2021; 22:11847. [PMID: 34769277 PMCID: PMC8584731 DOI: 10.3390/ijms222111847] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 12/12/2022] Open
Abstract
As the population ages, the incidence of neurodegenerative diseases is increasing. Due to intensive research, important steps in the elucidation of pathogenetic cascades have been made and significantly implicated mitochondrial dysfunction and oxidative stress. However, the available treatment in Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis is mainly symptomatic, providing minor benefits and, at most, slowing down the progression of the disease. Although in preclinical setting, drugs targeting mitochondrial dysfunction and oxidative stress yielded encouraging results, clinical trials failed or had inconclusive results. It is likely that by the time of clinical diagnosis, the pathogenetic cascades are full-blown and significant numbers of neurons have already degenerated, making it impossible for mitochondria-targeted or antioxidant molecules to stop or reverse the process. Until further research will provide more efficient molecules, a healthy lifestyle, with plenty of dietary antioxidants and avoidance of exogenous oxidants may postpone the onset of neurodegeneration, while familial cases may benefit from genetic testing and aggressive therapy started in the preclinical stage.
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Affiliation(s)
- Anamaria Jurcau
- Department of Psycho-Neurosciences and Rehabilitation, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania;
- Neurology Ward, Clinical Municipal Hospital “dr. G. Curteanu” Oradea, 410154 Oradea, Romania
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Duong QV, Levitsky Y, Dessinger MJ, Strubbe-Rivera JO, Bazil JN. Identifying Site-Specific Superoxide and Hydrogen Peroxide Production Rates From the Mitochondrial Electron Transport System Using a Computational Strategy. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab050. [PMID: 35330793 PMCID: PMC8788716 DOI: 10.1093/function/zqab050] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/02/2021] [Accepted: 09/14/2021] [Indexed: 01/07/2023]
Abstract
Mitochondrial reactive oxygen species (ROS) play important roles in cellular signaling; however, certain pathological conditions such as ischemia/reperfusion (I/R) injury disrupt ROS homeostasis and contribute to cell death. A major impediment to developing therapeutic measures against oxidative stress-induced cellular damage is the lack of a quantitative framework to identify the specific sources and regulatory mechanisms of mitochondrial ROS production. We developed a thermodynamically consistent, mass-and-charge balanced, kinetic model of mitochondrial ROS homeostasis focused on redox sites of electron transport chain complexes I, II, and III. The model was calibrated and corroborated using comprehensive data sets relevant to ROS homeostasis. The model predicts that complex I ROS production dominates other sources under conditions favoring a high membrane potential with elevated nicotinamide adenine dinucleotide (NADH) and ubiquinol (QH2) levels. In general, complex I contributes to significant levels of ROS production under pathological conditions, while complexes II and III are responsible for basal levels of ROS production, especially when QH2 levels are elevated. The model also reveals that hydrogen peroxide production by complex I underlies the non-linear relationship between ROS emission and O2 at low O2 concentrations. Lastly, the model highlights the need to quantify scavenging system activity under different conditions to establish a complete picture of mitochondrial ROS homeostasis. In summary, we describe the individual contributions of the electron transport system complex redox sites to total ROS emission in mitochondria respiring under various combinations of NADH- and Q-linked respiratory fuels under varying workloads.
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Affiliation(s)
- Quynh V Duong
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Yan Levitsky
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Maria J Dessinger
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Jasiel O Strubbe-Rivera
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan 48824, USA
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Chen J, Su Y, Lin R, Lin F, Shang P, Hussain R, Shi D. Effects of Acute Diquat Poisoning on Liver Mitochondrial Apoptosis and Autophagy in Ducks. Front Vet Sci 2021; 8:727766. [PMID: 34458360 PMCID: PMC8385319 DOI: 10.3389/fvets.2021.727766] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 07/12/2021] [Indexed: 12/21/2022] Open
Abstract
Diquat (DQ) is an effective herbicide and is widely used in agriculture. Due to persistent and frequent applications, it can enter into aquatic ecosystem and induce toxic effects to exposed aquatic animals. The residues of DQ via food chain accumulate in different tissues of exposed animals including humans and cause adverse toxic effects. Therefore, it is crucial and important to understand the mechanisms of toxic effects of DQ in exposed animals. We used ducks as test specimens to know the effects of acute DQ poisoning on mechanisms of apoptosis and autophagy in liver tissues. Results on comparison of various indexes of visceral organs including histopathological changes, apoptosis, autophagy-related genes, and protein expression indicated the adverse effects of DQ on the liver. The results of our experimental trial showed that DQ induces non-significant toxic effects on pro-apoptotic factors like BAX, BAK1, TNF-α, caspase series, and p53. The results revealed that anti-apoptotic gene Parkin was significantly upregulated, while an upward trend was also observed for Bcl2, suggesting that involvement of the anti-apoptotic factors in ducklings plays an important role in DQ poisoning. Results showed that DQ significantly increased the protein expression level of the autophagy factor Beclin 1 in the liver. Results on key autophagy factors like LC3A, LC3B, and p62 showed an upward trend at gene level, while the protein expression level of both LC3B and p62 reduced that might be associated with process of translation affected by the pro-apoptotic components such as apoptotic protease that inhibits the occurrence of autophagy while initiating cell apoptosis. The above results indicate that DQ can induce cell autophagy and apoptosis and the exposed organism may resist the toxic effects of DQ by increasing anti-apoptotic factors.
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Affiliation(s)
- Jiaxin Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yalin Su
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Renzhao Lin
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Fei Lin
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Peng Shang
- College of Animal Science, Tibet Agriculture and Animal Husbandry College, Linzhi, China
| | - Riaz Hussain
- Department of Pathology, Faculty of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Dayou Shi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
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Seminotti B, Roginski AC, Zanatta Â, Amaral AU, Fernandes T, Spannenberger KP, da Silva LHR, Ribeiro RT, Leipnitz G, Wajner M. S-adenosylmethionine induces mitochondrial dysfunction, permeability transition pore opening and redox imbalance in subcellular preparations of rat liver. J Bioenerg Biomembr 2021; 53:525-539. [PMID: 34347214 DOI: 10.1007/s10863-021-09914-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 07/17/2021] [Indexed: 01/03/2023]
Abstract
S-adenosylmethionine (AdoMet) predominantly accumulates in tissues and biological fluids of patients affected by liver dysmethylating diseases, particularly glycine N-methyltransferase, S-adenosylhomocysteine hydrolase and adenosine kinase deficiencies, as well as in some hepatic mtDNA depletion syndromes, whose pathogenesis of liver dysfunction is still poorly established. Therefore, in the present work, we investigated the effects of S-adenosylmethionine (AdoMet) on mitochondrial functions and redox homeostasis in rat liver. AdoMet decreased mitochondrial membrane potential and Ca2+ retention capacity, and these effects were fully prevented by cyclosporin A and ADP, indicating mitochondrial permeability transition (mPT) induction. It was also verified that the thiol-alkylating agent NEM prevented AdoMet-induced ΔΨm dissipation, implying a role for thiol oxidation in the mPT pore opening. AdoMet also increased ROS production and provoked protein and lipid oxidation. Furthermore, AdoMet reduced GSH levels and the activities of aconitase and α-ketoglutarate dehydrogenase. Free radical scavengers attenuated AdoMet effects on lipid peroxidation and GSH levels, supporting a role of ROS in these effects. It is therefore presumed that disturbance of mitochondrial functions associated with mPT and redox unbalance may represent relevant pathomechanisms of liver damage provoked by AdoMet in disorders in which this metabolite accumulates.
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Affiliation(s)
- Bianca Seminotti
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ana Cristina Roginski
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ângela Zanatta
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Alexandre Umpierrez Amaral
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Departamento de Ciências Biológicas, Universidade Regional Integrada do Alto Uruguai e das Missões, Avenida Sete de Setembro, 1621, Erechim, RS, 99709-910, Brazil
| | - Thabata Fernandes
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Kaleb Pinto Spannenberger
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Lucas Henrique Rodrigues da Silva
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rafael Teixeira Ribeiro
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Guilhian Leipnitz
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600, Prédio 21111, Porto Alegre, RS, 90035-003, Brazil
| | - Moacir Wajner
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. .,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600, Prédio 21111, Porto Alegre, RS, 90035-003, Brazil. .,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350, Porto Alegre, RS, 90035-007, Brazil.
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Weissman D, Maack C. Redox signaling in heart failure and therapeutic implications. Free Radic Biol Med 2021; 171:345-364. [PMID: 34019933 DOI: 10.1016/j.freeradbiomed.2021.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/17/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
Heart failure is a growing health burden worldwide characterized by alterations in excitation-contraction coupling, cardiac energetic deficit and oxidative stress. While current treatments are mostly limited to antagonization of neuroendocrine activation, more recent data suggest that also targeting metabolism may provide substantial prognostic benefit. However, although in a broad spectrum of preclinical models, oxidative stress plays a causal role for the development and progression of heart failure, no treatment that targets reactive oxygen species (ROS) directly has entered the clinical arena yet. In the heart, ROS derive from various sources, such as NADPH oxidases, xanthine oxidase, uncoupled nitric oxide synthase and mitochondria. While mitochondria are the primary source of ROS in the heart, communication between different ROS sources may be relevant for physiological signalling events as well as pathologically elevated ROS that deteriorate excitation-contraction coupling, induce hypertrophy and/or trigger cell death. Here, we review the sources of ROS in the heart, the modes of pathological activation of ROS formation as well as therapeutic approaches that may target ROS specifically in mitochondria.
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Affiliation(s)
- David Weissman
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany; Department of Internal Medicine 1, University Clinic Würzburg, Würzburg, Germany.
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47
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Fleminger G, Dayan A. The moonlighting activities of dihydrolipoamide dehydrogenase: Biotechnological and biomedical applications. J Mol Recognit 2021; 34:e2924. [PMID: 34164859 DOI: 10.1002/jmr.2924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 06/13/2021] [Indexed: 12/13/2022]
Abstract
Dihydrolipoamide dehydrogenase (DLDH) is a homodimeric flavin-dependent enzyme that catalyzes the NAD+ -dependent oxidation of dihydrolipoamide. The enzyme is part of several multi-enzyme complexes such as the Pyruvate Dehydrogenase system that transforms pyruvate into acetyl-co-A. Concomitantly with its redox activity, DLDH produces Reactive Oxygen Species (ROS), which are involved in cellular apoptotic processes. DLDH possesses several moonlighting functions. One of these is the capacity to adhere to metal-oxides surfaces. This was first exemplified by the presence of an exocellular form of the enzyme on the cell-wall surface of Rhodococcus ruber. This capability was evolutionarily conserved and identified in the human, mitochondrial, DLDH. The enzyme was modified with Arg-Gly-Asp (RGD) groups, which enabled its interaction with integrin-rich cancer cells followed by "integrin-assisted-endocytosis." This allowed harnessing the enzyme for cancer therapy. Combining the TiO2 -binding property with DLDH's ROS-production, enabled us to develop several medical applications including improving oesseointegration of TiO2 -based implants and photodynamic treatment for melanoma. The TiO2 -binding sites of both the bacterial and human DLDH's were identified on the proteins' molecules at regions that overlap with the binding site of E3-binding protein (E3BP). This protein is essential in forming the multiunit structure of PDC. Another moonlighting activity of DLDH, which is described in this Review, is its DNA-binding capacity that may affect DNA chelation and shredding leading to apoptotic processes in living cells. The typical ROS-generation by DLDH, which occurs in association with its enzymatic activity and its implications in cancer and apoptotic cell death are also discussed.
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Affiliation(s)
- Gideon Fleminger
- The Shmunis School of Biomedicine and Cancer Research, The George Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
| | - Avraham Dayan
- The Shmunis School of Biomedicine and Cancer Research, The George Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel
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48
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Mailloux RJ. An update on methods and approaches for interrogating mitochondrial reactive oxygen species production. Redox Biol 2021; 45:102044. [PMID: 34157640 PMCID: PMC8220584 DOI: 10.1016/j.redox.2021.102044] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/11/2021] [Indexed: 12/11/2022] Open
Abstract
The chief ROS formed by mitochondria are superoxide (O2·−) and hydrogen peroxide (H2O2). Superoxide is converted rapidly to H2O2 and therefore the latter is the chief ROS emitted by mitochondria into the cell. Once considered an unavoidable by-product of aerobic respiration, H2O2 is now regarded as a central mitokine used in mitochondrial redox signaling. However, it has been postulated that O2·− can also serve as a signal in mammalian cells. Progress in understanding the role of mitochondrial H2O2 in signaling is due to significant advances in the development of methods and technologies for its detection. Unfortunately, the development of techniques to selectively measure basal O2·− changes has been met with more significant hurdles due to its short half-life and the lack of specific probes. The development of sensitive techniques for the selective and real time measure of O2·− and H2O2 has come on two fronts: development of genetically encoded fluorescent proteins and small molecule reporters. In 2015, I published a detailed comprehensive review on the state of knowledge for mitochondrial ROS production and how it is controlled, which included an in-depth discussion of the up-to-date methods utilized for the detection of both superoxide (O2·−) and H2O2. In the article, I presented the challenges associated with utilizing these probes and their significance in advancing our collective understanding of ROS signaling. Since then, many other authors in the field of Redox Biology have published articles on the challenges and developments detecting O2·− and H2O2 in various organisms [[1], [2], [3]]. There has been significant advances in this state of knowledge, including the development of novel genetically encoded fluorescent H2O2 probes, several O2·− sensors, and the establishment of a toolkit of inhibitors and substrates for the interrogation of mitochondrial H2O2 production and the antioxidant defenses utilized to maintain the cellular H2O2 steady-state. Here, I provide an update on these methods and their implementation in furthering our understanding of how mitochondria serve as cell ROS stabilizing devices for H2O2 signaling. Details on the toolkit for interrogating the 12 sites for mitochondrial ROS production. Approaches to assess mitochondrial ROS clearance. Novel genetically encoded H2O2 sensors. Small chemical probes for sensitive detection of O2·−.
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Affiliation(s)
- Ryan J Mailloux
- The School of Human Nutrition, Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, Canada.
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Nemeria NS, Zhang X, Leandro J, Zhou J, Yang L, Houten SM, Jordan F. Toward an Understanding of the Structural and Mechanistic Aspects of Protein-Protein Interactions in 2-Oxoacid Dehydrogenase Complexes. Life (Basel) 2021; 11:407. [PMID: 33946784 PMCID: PMC8146983 DOI: 10.3390/life11050407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 12/24/2022] Open
Abstract
The 2-oxoglutarate dehydrogenase complex (OGDHc) is a key enzyme in the tricarboxylic acid (TCA) cycle and represents one of the major regulators of mitochondrial metabolism through NADH and reactive oxygen species levels. The OGDHc impacts cell metabolic and cell signaling pathways through the coupling of 2-oxoglutarate metabolism to gene transcription related to tumor cell proliferation and aging. DHTKD1 is a gene encoding 2-oxoadipate dehydrogenase (E1a), which functions in the L-lysine degradation pathway. The potentially damaging variants in DHTKD1 have been associated to the (neuro) pathogenesis of several diseases. Evidence was obtained for the formation of a hybrid complex between the OGDHc and E1a, suggesting a potential cross talk between the two metabolic pathways and raising fundamental questions about their assembly. Here we reviewed the recent findings and advances in understanding of protein-protein interactions in OGDHc and 2-oxoadipate dehydrogenase complex (OADHc), an understanding that will create a scaffold to help design approaches to mitigate the effects of diseases associated with dysfunction of the TCA cycle or lysine degradation. A combination of biochemical, biophysical and structural approaches such as chemical cross-linking MS and cryo-EM appears particularly promising to provide vital information for the assembly of 2-oxoacid dehydrogenase complexes, their function and regulation.
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Affiliation(s)
- Natalia S. Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Xu Zhang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Joao Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (J.L.); (S.M.H.)
| | - Jieyu Zhou
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Luying Yang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
| | - Sander M. Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (J.L.); (S.M.H.)
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA; (J.Z.); (L.Y.)
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Peng HY, Lucavs J, Ballard D, Das JK, Kumar A, Wang L, Ren Y, Xiong X, Song J. Metabolic Reprogramming and Reactive Oxygen Species in T Cell Immunity. Front Immunol 2021; 12:652687. [PMID: 33868291 PMCID: PMC8044852 DOI: 10.3389/fimmu.2021.652687] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/08/2021] [Indexed: 12/17/2022] Open
Abstract
T cells undergo metabolic reprogramming and multiple biological processes to satisfy their energetic and biosynthetic demands throughout their lifespan. Several of these metabolic pathways result in the generation of reactive oxygen species (ROS). The imbalance between ROS generation and scavenging could result in severe damage to the cells and potential cell death, ultimately leading to T cell-related diseases. Interestingly, ROS play an essential role in T cell immunity. Here, we introduce the important connectivity between T cell lifespan and the metabolic reprogramming among distinct T cell subsets. We also discuss the generation and sources of ROS production within T cell immunity as well as highlight recent research concerning the effects of ROS on T cell activities.
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Affiliation(s)
- Hao-Yun Peng
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Jason Lucavs
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Darby Ballard
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Jugal Kishore Das
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Anil Kumar
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Liqing Wang
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Yijie Ren
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Xiaofang Xiong
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Jianxun Song
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
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