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Ciccarone F, Ciriolo MR. Reprogrammed mitochondria: a central hub of cancer cell metabolism. Biochem Soc Trans 2024; 52:1305-1315. [PMID: 38716960 DOI: 10.1042/bst20231090] [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: 03/18/2024] [Revised: 04/22/2024] [Accepted: 04/26/2024] [Indexed: 06/27/2024]
Abstract
Mitochondria represent the metabolic hub of normal cells and play this role also in cancer but with different functional purposes. While cells in differentiated tissues have the prerogative of maintaining basal metabolism and support the biosynthesis of specialized products, cancer cells have to rewire the metabolic constraints imposed by the differentiation process. They need to balance the bioenergetic supply with the anabolic requirements that entail the intense proliferation rate, including nucleotide and membrane lipid biosynthesis. For this aim, mitochondrial metabolism is reprogrammed following the activation of specific oncogenic pathways or due to specific mutations of mitochondrial proteins. The main process leading to mitochondrial metabolic rewiring is the alteration of the tricarboxylic acid cycle favoring the appropriate orchestration of anaplerotic and cataplerotic reactions. According to the tumor type or the microenvironmental conditions, mitochondria may decouple glucose catabolism from mitochondrial oxidation in favor of glutaminolysis or disable oxidative phosphorylation for avoiding harmful production of free radicals. These and other metabolic settings can be also determined by the neo-production of oncometabolites that are not specific for the tissue of origin or the accumulation of metabolic intermediates able to boost pro-proliferative metabolism also impacting epigenetic/transcriptional programs. The full characterization of tumor-specific mitochondrial signatures may provide the identification of new biomarkers and therapeutic opportunities based on metabolic approaches.
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Affiliation(s)
- Fabio Ciccarone
- Department of Biology, University of Rome 'Tor Vergata', 00133 Rome, Italy
- IRCCS San Raffaele Roma, 00166 Rome, Italy
| | - Maria Rosa Ciriolo
- Department of Biology, University of Rome 'Tor Vergata', 00133 Rome, Italy
- IRCCS San Raffaele Roma, 00166 Rome, Italy
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2
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Guo M, Zhang J, Han J, Hu Y, Ni H, Yuan J, Sun Y, Liu M, Gao L, Liao W, Ma C, Liu Y, Li S, Li N. VEGFR2 blockade inhibits glioblastoma cell proliferation by enhancing mitochondrial biogenesis. J Transl Med 2024; 22:419. [PMID: 38702818 PMCID: PMC11067099 DOI: 10.1186/s12967-024-05155-1] [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: 12/06/2023] [Accepted: 04/02/2024] [Indexed: 05/06/2024] Open
Abstract
BACKGROUND Glioblastoma is an aggressive brain tumor linked to significant angiogenesis and poor prognosis. Anti-angiogenic therapies with vascular endothelial growth factor receptor 2 (VEGFR2) inhibition have been investigated as an alternative glioblastoma treatment. However, little is known about the effect of VEGFR2 blockade on glioblastoma cells per se. METHODS VEGFR2 expression data in glioma patients were retrieved from the public database TCGA. VEGFR2 intervention was implemented by using its selective inhibitor Ki8751 or shRNA. Mitochondrial biogenesis of glioblastoma cells was assessed by immunofluorescence imaging, mass spectrometry, and western blot analysis. RESULTS VEGFR2 expression was higher in glioma patients with higher malignancy (grade III and IV). VEGFR2 inhibition hampered glioblastoma cell proliferation and induced cell apoptosis. Mass spectrometry and immunofluorescence imaging showed that the anti-glioblastoma effects of VEGFR2 blockade involved mitochondrial biogenesis, as evidenced by the increases of mitochondrial protein expression, mitochondria mass, mitochondrial oxidative phosphorylation (OXPHOS), and reactive oxygen species (ROS) production, all of which play important roles in tumor cell apoptosis, growth inhibition, cell cycle arrest and cell senescence. Furthermore, VEGFR2 inhibition exaggerated mitochondrial biogenesis by decreased phosphorylation of AKT and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), which mobilized PGC1α into the nucleus, increased mitochondrial transcription factor A (TFAM) expression, and subsequently enhanced mitochondrial biogenesis. CONCLUSIONS VEGFR2 blockade inhibits glioblastoma progression via AKT-PGC1α-TFAM-mitochondria biogenesis signaling cascade, suggesting that VEGFR2 intervention might bring additive therapeutic values to anti-glioblastoma therapy.
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Affiliation(s)
- Min Guo
- Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
| | - Junhao Zhang
- Department of Medicine-Solna, Division of Cardiovascular Medicine, Karolinska University Hospital, Solna, 171 76, Stockholm, Sweden
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiang Han
- Department of Biopharmaceutical Sciences and National Key Laboratory of Frigid Zone Cardiovascular Diseases (NKLFZCD), College of Pharmacy, Harbin Medical University, Harbin, China
| | - Yingyue Hu
- Department of Biopharmaceutical Sciences and National Key Laboratory of Frigid Zone Cardiovascular Diseases (NKLFZCD), College of Pharmacy, Harbin Medical University, Harbin, China
| | - Hao Ni
- Department of Medicine-Solna, Division of Cardiovascular Medicine, Karolinska University Hospital, Solna, 171 76, Stockholm, Sweden
- Department of Gynaecology and Obstetrics, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Juan Yuan
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Yang Sun
- Department of Immunology and Shandong University-Karolinska Institutet Collaborative Laboratory, Shandong University Cheeloo Medical College, School of Basic Medicine, Jinan, China
| | - Meijuan Liu
- Department of Biopharmaceutical Sciences and National Key Laboratory of Frigid Zone Cardiovascular Diseases (NKLFZCD), College of Pharmacy, Harbin Medical University, Harbin, China
| | - Lifen Gao
- Department of Immunology and Shandong University-Karolinska Institutet Collaborative Laboratory, Shandong University Cheeloo Medical College, School of Basic Medicine, Jinan, China
| | - Wangjun Liao
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chunhong Ma
- Department of Immunology and Shandong University-Karolinska Institutet Collaborative Laboratory, Shandong University Cheeloo Medical College, School of Basic Medicine, Jinan, China
| | - Yaou Liu
- Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shuijie Li
- Department of Biopharmaceutical Sciences and National Key Laboratory of Frigid Zone Cardiovascular Diseases (NKLFZCD), College of Pharmacy, Harbin Medical University, Harbin, China.
| | - Nailin Li
- Department of Medicine-Solna, Division of Cardiovascular Medicine, Karolinska University Hospital, Solna, 171 76, Stockholm, Sweden.
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Shen Z, Sheng H, Zhao J, Xu J, Cai Z, Zhang H, Guo Z, Liu J, Liang H, Tan L, Gan S, Huang J, Zhu S. AQP8 Modulates Mitochondrial H 2O 2 Transport to Influence Glioma Proliferation. Cancer Invest 2024; 42:345-356. [PMID: 38742677 DOI: 10.1080/07357907.2024.2352467] [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: 01/06/2024] [Accepted: 05/03/2024] [Indexed: 05/16/2024]
Abstract
BACKGROUND Aquaporin-8 (AQP8) is involved in impacting glioma proliferation and can effect tumour growth by regulating Intracellular reactive oxygen species (ROS) signalling levels. In addition to transporting H2O2, AQP8 has been shown to affect ROS signaling, but evidence is lacking in gliomas. In this study, we aimed to investigate how AQP8 affects ROS signaling in gliomas. MATERIALS AND METHODS We constructed A172 and U251 cell lines with AQP8 knockdown and AQP8 rescue by CRISPR/Cas9 technology and overexpression of lentiviral vectors. We used CCK-8 and flow cytometry to test cell proliferation and cycle, immunofluorescence and Mito-Tracker CMXRos to observe the distribution of AQP8 expression in glioma cells, Amplex and DHE to study mitochondria release of H2O2, mitochondrial membrane potential (MMP) and NAD+/NADH ratio to assess mitochondrial function and protein blotting to detect p53 and p21 expression. RESULT We found that AQP8 co-localised with mitochondria and that knockdown of AQP8 inhibited the release of H2O2 from mitochondria and led to increased levels of ROS in mitochondria, thereby impairing mitochondrial function. We also discovered that AQP8 knockdown resulted in suppression of cell proliferation and was blocked at the G0/G1 phase with increased expression of mitochondrial ROS signalling-related p53/p21. CONCLUSIONS This finding provides further evidence for mechanistic studies of AQP8 as a prospective target for the treatment of gliomas.
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Affiliation(s)
- ZiHao Shen
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - HuaJun Sheng
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - Jing Zhao
- Xi'an Hospital of TCM, Xi'an, PR China
| | - Jin Xu
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - ZiLing Cai
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - Hao Zhang
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - Zhen Guo
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - JunNan Liu
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - Hang Liang
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - LiHao Tan
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - ShengWei Gan
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - Juan Huang
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
| | - ShuJuan Zhu
- Department of Human Anatomy, College of Basic Medicine, Chongqing Medical University, Chongqing, PR China
- Neuroscience Research Center, Chongqing Medical University, Chongqing, PR China
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Guerbette T, Rioux V, Bostoën M, Ciesielski V, Coppens-Exandier H, Buraud M, Lan A, Boudry G. Saturated fatty acids differently affect mitochondrial function and the intestinal epithelial barrier depending on their chain length in the in vitro model of IPEC-J2 enterocytes. Front Cell Dev Biol 2024; 12:1266842. [PMID: 38362040 PMCID: PMC10867211 DOI: 10.3389/fcell.2024.1266842] [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: 07/25/2023] [Accepted: 01/15/2024] [Indexed: 02/17/2024] Open
Abstract
Introduction: Maintenance of the intestinal barrier mainly relies on the mitochondrial function of intestinal epithelial cells that provide ATP through oxidative phosphorylation (OXPHOS). Dietary fatty acid overload might induce mitochondrial dysfunction of enterocytes and may increase intestinal permeability as indicated by previous in vitro studies with palmitic acid (C16:0). Yet the impact of other dietary saturated fatty acids remains poorly described. Methods: To address this question, the in vitro model of porcine enterocytes IPEC-J2 was treated for 3 days with 250 µM of lauric (C12:0), myristic (C14:0), palmitic (C16:0) or stearic (C18:0) acids. Results and discussion: Measurement of the transepithelial electrical resistance, reflecting tight junction integrity, revealed that only C16:0 and C18:0 increased epithelial permeability, without modifying the expression of genes encoding tight junction proteins. Bioenergetic measurements indicated that C16:0 and C18:0 were barely β-oxidized by IPEC-J2. However, they rather induced significant OXPHOS uncoupling and reduced ATP production compared to C12:0 and C14:0. These bioenergetic alterations were associated with elevated mitochondrial reactive oxygen species production and mitochondrial fission. Although C12:0 and C14:0 treatment induced significant lipid storage and enhanced fusion of the mitochondrial network, it only mildly decreased ATP production without altering epithelial barrier. These results point out that the longer chain fatty acids C16:0 and C18:0 increased intestinal permeability, contrary to C12:0 and C14:0. In addition, C16:0 and C18:0 induced an important energy deprivation, notably via increased proton leaks, mitochondrial remodeling, and elevated ROS production in enterocytes compared to C12:0 and C14:0.
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Affiliation(s)
- Thomas Guerbette
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
| | - Vincent Rioux
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
- Institut Agro Rennes-Angers, Rennes, France
| | - Mégane Bostoën
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
| | - Vincent Ciesielski
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
- Institut Agro Rennes-Angers, Rennes, France
| | | | - Marine Buraud
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
| | - Annaïg Lan
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
- UMR PNCA, AgroParisTech, INRAE, Université Paris-Saclay, Paris, France
| | - Gaëlle Boudry
- Institut NuMeCan, INRAE, INSERM, University Rennes, Rennes, France
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Holendová B, Benáková Š, Křivonosková M, Pavluch V, Tauber J, Gabrielová E, Ježek P, Plecitá-Hlavatá L. NADPH oxidase 4 in mouse β cells participates in inflammation on chronic nutrient overload. Obesity (Silver Spring) 2024; 32:339-351. [PMID: 38086768 DOI: 10.1002/oby.23956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 09/13/2023] [Accepted: 10/06/2023] [Indexed: 01/16/2024]
Abstract
OBJECTIVE By exposing mice carrying a deletion of NADPH oxidase isoform 4, NOX4, specifically in pancreatic β cells (βNOX4-/-) to nutrient excess stimulated by a high-fat diet (HFD), this study aimed to elucidate the role of β-cell redox status in the development of meta-inflammation within the diabetic phenotype. METHODS The authors performed basic phenotyping of βNOX4-/- mice on HFD involving insulin and glycemic analyses, histochemistry of adipocytes, indirect calorimetry, and cytokine analyses. To characterize local inflammation, the study used caspase-1 activity assay, interleukin-1β immunochemistry, and real-time polymerase chain reaction during coculturing of β cells with macrophages. RESULTS The phenotype of βNOX4-/- mice on HFD was not associated with hyperinsulinemia and hyperglycemia but showed accumulation of excessive lipids in epididymal fat and β cells. Surprisingly, mice showed significantly reduced systemic inflammation. Decreased interleukin-1β protein levels and downregulated NLRP3-inflammasome activity were observed on chronic glucose overload in βNOX4-/- isolated islets and NOX4-silenced INS1-E cells resulting in attenuated proinflammatory polarization of macrophages/monocytes in vitro and in situ and reduced local islet inflammation. CONCLUSIONS Experimental evidence suggests that NOX4 pro-oxidant activity in β cells is involved in NLRP3-inflammasome activation during chronic nutrient overload and participates in local inflammatory signaling and perhaps toward peripheral tissues, contributing to a diabetic inflammatory phenotype.
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Affiliation(s)
- Blanka Holendová
- Laboratory of Pancreatic Islet Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Štěpánka Benáková
- Laboratory of Pancreatic Islet Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Monika Křivonosková
- Laboratory of Pancreatic Islet Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University, Prague, Czech Republic
| | - Vojtěch Pavluch
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Tauber
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Eva Gabrielová
- Department of Medical Chemistry and Biochemistry, Palacký University, Olomouc, Czech Republic
| | - Petr Ježek
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Lydie Plecitá-Hlavatá
- Laboratory of Pancreatic Islet Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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Ježek P, Jabůrek M, Holendová B, Engstová H, Dlasková A. Mitochondrial Cristae Morphology Reflecting Metabolism, Superoxide Formation, Redox Homeostasis, and Pathology. Antioxid Redox Signal 2023; 39:635-683. [PMID: 36793196 PMCID: PMC10615093 DOI: 10.1089/ars.2022.0173] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023]
Abstract
Significance: Mitochondrial (mt) reticulum network in the cell possesses amazing ultramorphology of parallel lamellar cristae, formed by the invaginated inner mitochondrial membrane. Its non-invaginated part, the inner boundary membrane (IBM) forms a cylindrical sandwich with the outer mitochondrial membrane (OMM). Crista membranes (CMs) meet IBM at crista junctions (CJs) of mt cristae organizing system (MICOS) complexes connected to OMM sorting and assembly machinery (SAM). Cristae dimensions, shape, and CJs have characteristic patterns for different metabolic regimes, physiological and pathological situations. Recent Advances: Cristae-shaping proteins were characterized, namely rows of ATP-synthase dimers forming the crista lamella edges, MICOS subunits, optic atrophy 1 (OPA1) isoforms and mitochondrial genome maintenance 1 (MGM1) filaments, prohibitins, and others. Detailed cristae ultramorphology changes were imaged by focused-ion beam/scanning electron microscopy. Dynamics of crista lamellae and mobile CJs were demonstrated by nanoscopy in living cells. With tBID-induced apoptosis a single entirely fused cristae reticulum was observed in a mitochondrial spheroid. Critical Issues: The mobility and composition of MICOS, OPA1, and ATP-synthase dimeric rows regulated by post-translational modifications might be exclusively responsible for cristae morphology changes, but ion fluxes across CM and resulting osmotic forces might be also involved. Inevitably, cristae ultramorphology should reflect also mitochondrial redox homeostasis, but details are unknown. Disordered cristae typically reflect higher superoxide formation. Future Directions: To link redox homeostasis to cristae ultramorphology and define markers, recent progress will help in uncovering mechanisms involved in proton-coupled electron transfer via the respiratory chain and in regulation of cristae architecture, leading to structural determination of superoxide formation sites and cristae ultramorphology changes in diseases. Antioxid. Redox Signal. 39, 635-683.
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Affiliation(s)
- Petr Ježek
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Martin Jabůrek
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Blanka Holendová
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Hana Engstová
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Andrea Dlasková
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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7
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Kawano I, Bazila B, Ježek P, Dlasková A. Mitochondrial Dynamics and Cristae Shape Changes During Metabolic Reprogramming. Antioxid Redox Signal 2023; 39:684-707. [PMID: 37212238 DOI: 10.1089/ars.2023.0268] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Significance: The architecture of the mitochondrial network and cristae critically impact cell differentiation and identity. Cells undergoing metabolic reprogramming to aerobic glycolysis (Warburg effect), such as immune cells, stem cells, and cancer cells, go through controlled modifications in mitochondrial architecture, which is critical for achieving the resulting cellular phenotype. Recent Advances: Recent studies in immunometabolism have shown that the manipulation of mitochondrial network dynamics and cristae shape directly affects T cell phenotype and macrophage polarization through altering energy metabolism. Similar manipulations also alter the specific metabolic phenotypes that accompany somatic reprogramming, stem cell differentiation, and cancer cells. The modulation of oxidative phosphorylation activity, accompanied by changes in metabolite signaling, reactive oxygen species generation, and adenosine triphosphate levels, is the shared underlying mechanism. Critical Issues: The plasticity of mitochondrial architecture is particularly vital for metabolic reprogramming. Consequently, failure to adapt the appropriate mitochondrial morphology often compromises the differentiation and identity of the cell. Immune, stem, and tumor cells exhibit striking similarities in their coordination of mitochondrial morphology with metabolic pathways. However, although many general unifying principles can be observed, their validity is not absolute, and the mechanistic links thus need to be further explored. Future Directions: Better knowledge of the molecular mechanisms involved and their relationships to both mitochondrial network and cristae morphology will not only further deepen our understanding of energy metabolism but may also contribute to improved therapeutic manipulation of cell viability, differentiation, proliferation, and identity in many different cell types. Antioxid. Redox Signal. 39, 684-707.
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Affiliation(s)
- Ippei Kawano
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Bazila Bazila
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Petr Ježek
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Andrea Dlasková
- Laboratory of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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8
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Ježek P. Pitfalls of Mitochondrial Redox Signaling Research. Antioxidants (Basel) 2023; 12:1696. [PMID: 37759999 PMCID: PMC10525995 DOI: 10.3390/antiox12091696] [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: 08/04/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Redox signaling from mitochondria (mt) to the cytosol and plasma membrane (PM) has been scarcely reported, such as in the case of hypoxic cell adaptation or (2-oxo-) 2-keto-isocaproate (KIC) β-like-oxidation stimulating insulin secretion in pancreatic β-cells. Mutual redox state influence between mitochondrial major compartments, the matrix and the intracristal space, and the cytosol is therefore derived theoretically in this article to predict possible conditions, when mt-to-cytosol and mt-to-PM signals may occur, as well as conditions in which the cytosolic redox signaling is not overwhelmed by the mitochondrial antioxidant capacity. Possible peroxiredoxin 3 participation in mt-to-cytosol redox signaling is discussed, as well as another specific case, whereby mitochondrial superoxide release is diminished, whereas the matrix MnSOD is activated. As a result, the enhanced conversion to H2O2 allows H2O2 diffusion into the cytosol, where it could be a predominant component of the H2O2 release. In both of these ways, mt-to-cytosol and mt-to-PM signals may be realized. Finally, the use of redox-sensitive probes is discussed, which disturb redox equilibria, and hence add a surplus redox-buffering to the compartment, where they are localized. Specifically, when attempts to quantify net H2O2 fluxes are to be made, this should be taken into account.
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Affiliation(s)
- Petr Ježek
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, 14220 Prague, Czech Republic
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Weiser A, Hermant A, Bermont F, Sizzano F, Karaz S, Alvarez-Illera P, Santo-Domingo J, Sorrentino V, Feige JN, De Marchi U. The mitochondrial calcium uniporter (MCU) activates mitochondrial respiration and enhances mobility by regulating mitochondrial redox state. Redox Biol 2023; 64:102759. [PMID: 37302345 PMCID: PMC10363449 DOI: 10.1016/j.redox.2023.102759] [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: 04/21/2023] [Revised: 05/14/2023] [Accepted: 05/21/2023] [Indexed: 06/13/2023] Open
Abstract
Regulation of mitochondrial redox balance is emerging as a key event for cell signaling in both physiological and pathological conditions. However, the link between the mitochondrial redox state and the modulation of these conditions remains poorly defined. Here, we discovered that activation of the evolutionary conserved mitochondrial calcium uniporter (MCU) modulates mitochondrial redox state. By using mitochondria-targeted redox and calcium sensors and genetic MCU-ablated models, we provide evidence of the causality between MCU activation and net reduction of mitochondrial (but not cytosolic) redox state. Redox modulation of redox-sensitive groups via MCU stimulation is required for maintaining respiratory capacity in primary human myotubes and C. elegans, and boosts mobility in worms. The same benefits are obtained bypassing MCU via direct pharmacological reduction of mitochondrial proteins. Collectively, our results demonstrate that MCU regulates mitochondria redox balance and that this process is required to promote the MCU-dependent effects on mitochondrial respiration and mobility.
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Affiliation(s)
- Anna Weiser
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland; Molecular Nutritional Medicine, Else Kröner Fresenius Center for Nutritional Medicine, Technische Universität München, 85354 Freising, Germany
| | - Aurélie Hermant
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Flavien Bermont
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Federico Sizzano
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Sonia Karaz
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Pilar Alvarez-Illera
- Department of Biochemistry and Molecular Biology, University of Valladolid, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), 47003 Valladolid, Spain
| | - Jaime Santo-Domingo
- Department of Biochemistry and Molecular Biology, University of Valladolid, Unidad de Excelencia Instituto de Biología y Genética Molecular (IBGM), 47003 Valladolid, Spain
| | - Vincenzo Sorrentino
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 119228, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117596, Singapore
| | - Jerome N Feige
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Umberto De Marchi
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, CH-1015 Lausanne, Switzerland.
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Kushwaha AD, Varshney R, Saraswat D. Effect of hypobaric hypoxia on the fiber type transition of skeletal muscle: a synergistic therapy of exercise preconditioning with a nanocurcumin formulation. J Physiol Biochem 2023:10.1007/s13105-023-00965-1. [PMID: 37147493 DOI: 10.1007/s13105-023-00965-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 04/26/2023] [Indexed: 05/07/2023]
Abstract
Hypobaric hypoxia (HH) leads to various adverse effects on skeletal muscles, including atrophy and reduced oxidative work capacity. However, the effects of HH on muscle fatigue resistance and myofiber remodeling are largely unexplored. Therefore, the present study aimed to explore the impact of HH on slow-oxidative fibers and to evaluate the ameliorative potential of exercise preconditioning and nanocurcumin formulation on muscle anti-fatigue ability. C2C12 cells (murine myoblasts) were used to assess the effect of hypoxia (0.5%, 24 h) with and without the nanocurcumin formulation (NCF) on myofiber phenotypic conversion. To further validate this hypothesis, male Sprague Dawley rats were exposed to a simulated HH (7620 m) for 7 days, along with NCF administration and/or exercise training. Both in vitro and in vivo studies revealed a significant reduction in slow-oxidative fibers (p < 0.01, 61% vs. normoxia control) under hypoxia. There was also a marked decrease in exhaustion time (p < 0.01, 65% vs. normoxia) in hypoxia control rats, indicating a reduced work capacity. Exercise preconditioning along with NCF supplementation significantly increased the slow-oxidative fiber proportion and exhaustion time while maintaining mitochondrial homeostasis. These findings suggest that HH leads to an increased transition of slow-oxidative fibers to fast glycolytic fibers and increased muscular fatigue. Administration of NCF in combination with exercise preconditioning restored this myofiber remodeling and improved muscle anti-fatigue ability.
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Affiliation(s)
- Asha D Kushwaha
- Pathophysiology and Disruptive Technologies, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India, 110054
| | - Rajeev Varshney
- Pathophysiology and Disruptive Technologies, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India, 110054
| | - Deepika Saraswat
- Pathophysiology and Disruptive Technologies, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India, 110054.
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11
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Vitale M, Sanz A, Scialò F. Mitochondrial redox signaling: a key player in aging and disease. Aging (Albany NY) 2023; 15:2817-2818. [PMID: 37052982 PMCID: PMC10188336 DOI: 10.18632/aging.204659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/16/2023] [Indexed: 04/14/2023]
Affiliation(s)
- Maria Vitale
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
- CEINGE, Biotecnologie Avanzate, Naples, 80131, Italy
| | - Alberto Sanz
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, Glasgow, United Kingdom
| | - Filippo Scialò
- CEINGE, Biotecnologie Avanzate, Naples, 80131, Italy
- Department of Translational Medical Sciences, University of Campania Luigi Vanvitelli, 80131 Naples, Italy
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12
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Shannon N, Gravelle R, Cunniff B. Mitochondrial trafficking and redox/phosphorylation signaling supporting cell migration phenotypes. Front Mol Biosci 2022; 9:925755. [PMID: 35936783 PMCID: PMC9355248 DOI: 10.3389/fmolb.2022.925755] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/05/2022] [Indexed: 11/13/2022] Open
Abstract
Regulation of cell signaling cascades is critical in making sure the response is activated spatially and for a desired duration. Cell signaling cascades are spatially and temporally controlled through local protein phosphorylation events which are determined by the activation of specific kinases and/or inactivation of phosphatases to elicit a complete and thorough response. For example, A-kinase-anchoring proteins (AKAPs) contribute to the local regulated activity protein kinase A (PKA). The activity of kinases and phosphatases can also be regulated through redox-dependent cysteine modifications that mediate the activity of these proteins. A primary example of this is the activation of the epidermal growth factor receptor (EGFR) and the inactivation of the phosphatase and tensin homologue (PTEN) phosphatase by reactive oxygen species (ROS). Therefore, the local redox environment must play a critical role in the timing and magnitude of these events. Mitochondria are a primary source of ROS and energy (ATP) that contributes to redox-dependent signaling and ATP-dependent phosphorylation events, respectively. The strategic positioning of mitochondria within cells contributes to intracellular gradients of ROS and ATP, which have been shown to correlate with changes to protein redox and phosphorylation status driving downstream cellular processes. In this review, we will discuss the relationship between subcellular mitochondrial positioning and intracellular ROS and ATP gradients that support dynamic oxidation and phosphorylation signaling and resulting cellular effects, specifically associated with cell migration signaling.
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Affiliation(s)
- Nathaniel Shannon
- Department of Pathology and Laboratory Medicine, Redox Biology Program, University of Vermont Larner College of Medicine, Burlington, VT, United States
| | - Randi Gravelle
- Department of Pathology and Laboratory Medicine, Redox Biology Program, University of Vermont Larner College of Medicine, Burlington, VT, United States
| | - Brian Cunniff
- Department of Pathology and Laboratory Medicine, Redox Biology Program, University of Vermont Larner College of Medicine, Burlington, VT, United States
- University of Vermont Cancer Center, University of Vermont Larner College of Medicine, Burlington, VT, United States
- *Correspondence: Brian Cunniff,
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13
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Abstract
Low-level laser therapy (LLLT) has become an important part of the therapeutic process in various diseases. However, despite the broad use of LLLT in everyday clinical practice, the full impact of LLLT on cell life processes has not been fully understood. This paper presents the current state of knowledge concerning the mechanisms of action of LLLT on cells. A better understanding of the molecular processes occurring within the cell after laser irradiation may result in introducing numerous novel clinical applications of LLLT and potentially increases the safety profile of this therapy.
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14
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Ježek P, Holendová B, Jabůrek M, Dlasková A, Plecitá-Hlavatá L. Contribution of Mitochondria to Insulin Secretion by Various Secretagogues. Antioxid Redox Signal 2022; 36:920-952. [PMID: 34180254 PMCID: PMC9125579 DOI: 10.1089/ars.2021.0113] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Significance: Mitochondria determine glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells by elevating ATP synthesis. As the metabolic and redox hub, mitochondria provide numerous links to the plasma membrane channels, insulin granule vesicles (IGVs), cell redox, NADH, NADPH, and Ca2+ homeostasis, all affecting insulin secretion. Recent Advances: Mitochondrial redox signaling was implicated in several modes of insulin secretion (branched-chain ketoacid [BCKA]-, fatty acid [FA]-stimulated). Mitochondrial Ca2+ influx was found to enhance GSIS, reflecting cytosolic Ca2+ oscillations induced by action potential spikes (intermittent opening of voltage-dependent Ca2+ and K+ channels) or the superimposed Ca2+ release from the endoplasmic reticulum (ER). The ATPase inhibitory factor 1 (IF1) was reported to tune the glucose sensitivity range for GSIS. Mitochondrial protein kinase A was implicated in preventing the IF1-mediated inhibition of the ATP synthase. Critical Issues: It is unknown how the redox signal spreads up to the plasma membrane and what its targets are, what the differences in metabolic, redox, NADH/NADPH, and Ca2+ signaling, and homeostasis are between the first and second GSIS phase, and whether mitochondria can replace ER in the amplification of IGV exocytosis. Future Directions: Metabolomics studies performed to distinguish between the mitochondrial matrix and cytosolic metabolites will elucidate further details. Identifying the targets of cell signaling into mitochondria and of mitochondrial retrograde metabolic and redox signals to the cell will uncover further molecular mechanisms for insulin secretion stimulated by glucose, BCKAs, and FAs, and the amplification of secretion by glucagon-like peptide (GLP-1) and metabotropic receptors. They will identify the distinction between the hub β-cells and their followers in intact and diabetic states. Antioxid. Redox Signal. 36, 920-952.
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Affiliation(s)
- Petr Ježek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Blanka Holendová
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Jabůrek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Andrea Dlasková
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Lydie Plecitá-Hlavatá
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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15
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Antioxidant Role and Cardiolipin Remodeling by Redox-Activated Mitochondrial Ca 2+-Independent Phospholipase A 2γ in the Brain. Antioxidants (Basel) 2022; 11:antiox11020198. [PMID: 35204081 PMCID: PMC8868467 DOI: 10.3390/antiox11020198] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
Mitochondrial Ca2+-independent phospholipase A2γ (iPLA2γ/PNPLA8) was previously shown to be directly activated by H2O2 and release free fatty acids (FAs) for FA-dependent H+ transport mediated by the adenine nucleotide translocase (ANT) or uncoupling protein 2 (UCP2). The resulting mild mitochondrial uncoupling and consequent partial attenuation of mitochondrial superoxide production lead to an antioxidant effect. However, the antioxidant role of iPLA2γ in the brain is not completely understood. Here, using wild-type and iPLA2γ-KO mice, we demonstrate the ability of tert-butylhydroperoxide (TBHP) to activate iPLA2γ in isolated brain mitochondria, with consequent liberation of FAs and lysophospholipids. The liberated FA caused an increase in respiratory rate, which was fully inhibited by carboxyatractyloside (CATR), a specific inhibitor of ANT. Employing detailed lipidomic analysis, we also demonstrate a typical cleavage pattern for TBHP-activated iPLA2γ, reflecting cleavage of glycerophospholipids from both sn-1 and sn-2 positions releasing saturated FAs, monoenoic FAs, and predominant polyunsaturated FAs. The acute antioxidant role of iPLA2γ-released FAs is supported by monitoring both intramitochondrial superoxide and extramitochondrial H2O2 release. We also show that iPLA2γ-KO mice were more sensitive to stimulation by pro-inflammatory lipopolysaccharide, as reflected by the concomitant increase in protein carbonyls in the brain and pro-inflammatory IL-6 release in the serum. These data support the antioxidant and anti-inflammatory role of iPLA2γ in vivo. Our data also reveal a substantial decrease of several high molecular weight cardiolipin (CL) species and accumulation of low molecular weight CL species in brain mitochondria of iPLA2γ-KO mice. Collectively, our results support a key role of iPLA2γ in the remodeling of lower molecular weight immature cardiolipins with predominantly saturated acyl chains to high molecular weight mature cardiolipins with highly unsaturated PUFA acyl chains, typical for the brain.
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16
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Putative role of uncoupling proteins in mitochondria-nucleus communications and DNA damage response. J Biosci 2021. [DOI: 10.1007/s12038-021-00224-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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de Siqueira Patriota LL, do Nascimento Santos DKD, da Silva Barros BR, de Souza Aguiar LM, Silva YA, Dos Santos ACLA, Gama E Silva M, Barroso Coelho LCB, Paiva PMG, Pontual EV, de Melo CML, Mendes RL, Napoleáo TH. Evaluation of the In Vivo Acute Toxicity and In Vitro Hemolytic and Immunomodulatory Activities of the Moringa oleifera Flower Trypsin Inhibitor (MoFTI). Protein Pept Lett 2021; 28:665-674. [PMID: 33191881 DOI: 10.2174/0929866527999201113105858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/09/2020] [Accepted: 10/16/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Protease inhibitors have been isolated from plants and present several biological activities, including immunomodulatory action. OBJECTIVE This work aimed to evaluate a Moringa oleifera flower trypsin inhibitor (MoFTI) for acute toxicity in mice, hemolytic activity on mice erythrocytes and immunomodulatory effects on mice splenocytes. METHODS The acute toxicity was evaluated using Swiss female mice that received a single dose of the vehicle control or MoFTI (300 mg/kg, i.p.). Behavioral alterations were observed 15-240 min after administration, and survival, weight gain, and water and food consumption were analyzed daily. Organ weights and hematological parameters were analyzed after 14 days. Hemolytic activity of MoFTI was tested using Swiss female mice erythrocytes. Splenocytes obtained from BALB/c mice were cultured in the absence or presence of MoFTI for the evaluation of cell viability and proliferation. Mitochondrial membrane potential (Δψm) and reactive oxygen species (ROS) levels were also determined. Furthermore, the culture supernatants were analyzed for the presence of cytokines and nitric oxide (NO). RESULTS MoFTI did not cause death or any adverse effects on the mice except for abdominal contortions at 15-30 min after administration. MoFTI did not exhibit a significant hemolytic effect. In addition, MoFTI did not induce apoptosis or necrosis in splenocytes and had no effect on cell proliferation. Increases in cytosolic and mitochondrial ROS release, as well as Δψm reduction, were observed in MoFTI-treated cells. MoFTI was observed to induce TNF-α, IFN-γ, IL-6, IL-10, and NO release. CONCLUSION These results contribute to the ongoing evaluation of the antitumor potential of MoFTI and its effects on other immunological targets.
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Affiliation(s)
| | | | | | | | - Yasmym Araújo Silva
- Laboratorio de Oncologia Experimental, Universidade Federal do Vale do Sao Francisco, Petrolina, Brazil
| | | | - Mariana Gama E Silva
- Laboratorio de Oncologia Experimental, Universidade Federal do Vale do Sao Francisco, Petrolina, Brazil
| | | | | | - Emmanuel Viana Pontual
- Departamento de Morfologia e Fisiologia Animal, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | | | - Rosemairy Luciane Mendes
- Laboratorio de Oncologia Experimental, Universidade Federal do Vale do Sao Francisco, Petrolina, Brazil
| | - Thiago Henrique Napoleáo
- Departamento de Bioquimica, Centro de Biociencias, Universidade Federal de Pernambuco, Recife, Brazil
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18
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Stimulation of AMPK Prevents Diabetes-Induced Photoreceptor Cell Degeneration. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5587340. [PMID: 34093959 PMCID: PMC8140850 DOI: 10.1155/2021/5587340] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/19/2021] [Accepted: 04/01/2021] [Indexed: 12/18/2022]
Abstract
Diabetic retinopathy (DR) is a kind of severe retinal neurodegeneration. The advanced glycation end products (AGEs) affect autophagy, and mitochondrial function is involved in DR. Adenosine-activated protein kinase (AMPK) is an important metabolic sensor that can regulate energy homeostasis in cells. However, the effect of AMPK in DR is still not fully understood. In this study, we investigated the effect of AMPK on diabetes-induced photoreceptor cell degeneration. In vivo, a diabetic mouse model was established by streptozotocin (STZ) injection. Haematoxylin-eosin (HE) staining was used to observe retinal morphology and measure the thicknesses of different layers in the retina. Electroretinogram (ERG) was used to evaluate retinal function. In vitro, 661w cells were treated with AGEs with/without an AMPK agonist (metformin) or AMPK inhibitor (compound C). Flow cytometry and CCK-8 assays were used to analyse apoptosis. Mitochondrial membrane potential was analysed by JC-1. Western blotting and qRT-PCR were used to examine the expression of related proteins and genes, respectively. The wave amplitude and the thickness of the outer nuclear layer were decreased in diabetic mice. The expression of rhodopsin and opsin was also decreased in diabetic mice. In vitro, the percentage of apoptotic cells was increased, the expression of the apoptosis-related protein Bax was increased, and Bcl-2 was decreased after AGE treatment in 661w cells. The expression of the autophagy-related protein LC3 was decreased, and p62 was increased. The mitochondrial-related gene expression and membrane potential were decreased, and mitochondrial morphology was abnormal, as observed by TEM. However, AMPK stimulation ameliorated this effect. These results indicate that AMPK stimulation can delay diabetes-induced photoreceptor degeneration by regulating autophagy and mitochondrial function.
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19
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Jabůrek M, Průchová P, Holendová B, Galkin A, Ježek P. Antioxidant Synergy of Mitochondrial Phospholipase PNPLA8/iPLA2γ with Fatty Acid-Conducting SLC25 Gene Family Transporters. Antioxidants (Basel) 2021; 10:antiox10050678. [PMID: 33926059 PMCID: PMC8146845 DOI: 10.3390/antiox10050678] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/13/2021] [Accepted: 04/22/2021] [Indexed: 02/07/2023] Open
Abstract
Patatin-like phospholipase domain-containing protein PNPLA8, also termed Ca2+-independent phospholipase A2γ (iPLA2γ), is addressed to the mitochondrial matrix (or peroxisomes), where it may manifest its unique activity to cleave phospholipid side-chains from both sn-1 and sn-2 positions, consequently releasing either saturated or unsaturated fatty acids (FAs), including oxidized FAs. Moreover, iPLA2γ is directly stimulated by H2O2 and, hence, is activated by redox signaling or oxidative stress. This redox activation permits the antioxidant synergy with mitochondrial uncoupling proteins (UCPs) or other SLC25 mitochondrial carrier family members by FA-mediated protonophoretic activity, termed mild uncoupling, that leads to diminishing of mitochondrial superoxide formation. This mechanism allows for the maintenance of the steady-state redox status of the cell. Besides the antioxidant role, we review the relations of iPLA2γ to lipid peroxidation since iPLA2γ is alternatively activated by cardiolipin hydroperoxides and hypothetically by structural alterations of lipid bilayer due to lipid peroxidation. Other iPLA2γ roles include the remodeling of mitochondrial (or peroxisomal) membranes and the generation of specific lipid second messengers. Thus, for example, during FA β-oxidation in pancreatic β-cells, H2O2-activated iPLA2γ supplies the GPR40 metabotropic FA receptor to amplify FA-stimulated insulin secretion. Cytoprotective roles of iPLA2γ in the heart and brain are also discussed.
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Affiliation(s)
- Martin Jabůrek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1084, 14220 Prague, Czech Republic; (P.P.); (B.H.); (P.J.)
- Correspondence: ; Tel.: +420-296442789
| | - Pavla Průchová
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1084, 14220 Prague, Czech Republic; (P.P.); (B.H.); (P.J.)
| | - Blanka Holendová
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1084, 14220 Prague, Czech Republic; (P.P.); (B.H.); (P.J.)
| | - Alexander Galkin
- Department of Pediatrics, Division of Neonatology, Columbia University William Black Building, New York, NY 10032, USA;
| | - Petr Ježek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1084, 14220 Prague, Czech Republic; (P.P.); (B.H.); (P.J.)
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20
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Pagacz J, Broniec A, Wolska M, Osyczka A, Borek A. ROS signaling capacity of cytochrome bc 1: Opposing effects of adaptive and pathogenic mitochondrial mutations. Free Radic Biol Med 2021; 163:243-254. [PMID: 33352219 DOI: 10.1016/j.freeradbiomed.2020.12.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Accepted: 12/12/2020] [Indexed: 01/06/2023]
Abstract
Cytochrome bc1, also known as mitochondrial complex III, is considered to be one of the important producers of reactive oxygen species (ROS) in living organisms. Under physiological conditions, a certain level of ROS produced by mitochondrial electron transport chain (ETC) might be beneficial and take part in cellular signaling. However, elevated levels of ROS might exhibit negative effects, resulting in cellular damage. It is well known that inhibiting the electron flow within mitochondrial complex III leads to high production of ROS. However, superoxide production by cytochrome bc1 in a non-inhibited system remained controversial. Here, we propose a novel method for ROS detection in ETC hybrid system in solution comprising bacterial cytochrome bc1 and mitochondrial complex IV. We clearly show that non-inhibited cytochrome bc1 generates ROS and that adaptive and pathogenic mitochondrial mutations suppress and enhance ROS production, respectively. We also noted that cytochrome bc1 produces ROS in a rate-dependent manner and that the mechanism of ROS generation changes according to the rate of operation of the enzyme. This dependency has not yet been reported, but seems to be crucial when discussing ROS signaling originating from mitochondria.
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Affiliation(s)
- Jakub Pagacz
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Agnieszka Broniec
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Małgorzata Wolska
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Artur Osyczka
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Arkadiusz Borek
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
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Ježek P, Holendová B, Jabůrek M, Tauber J, Dlasková A, Plecitá-Hlavatá L. The Pancreatic β-Cell: The Perfect Redox System. Antioxidants (Basel) 2021; 10:antiox10020197. [PMID: 33572903 PMCID: PMC7912581 DOI: 10.3390/antiox10020197] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/20/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Pancreatic β-cell insulin secretion, which responds to various secretagogues and hormonal regulations, is reviewed here, emphasizing the fundamental redox signaling by NADPH oxidase 4- (NOX4-) mediated H2O2 production for glucose-stimulated insulin secretion (GSIS). There is a logical summation that integrates both metabolic plus redox homeostasis because the ATP-sensitive K+ channel (KATP) can only be closed when both ATP and H2O2 are elevated. Otherwise ATP would block KATP, while H2O2 would activate any of the redox-sensitive nonspecific calcium channels (NSCCs), such as TRPM2. Notably, a 100%-closed KATP ensemble is insufficient to reach the -50 mV threshold plasma membrane depolarization required for the activation of voltage-dependent Ca2+ channels. Open synergic NSCCs or Cl- channels have to act simultaneously to reach this threshold. The resulting intermittent cytosolic Ca2+-increases lead to the pulsatile exocytosis of insulin granule vesicles (IGVs). The incretin (e.g., GLP-1) amplification of GSIS stems from receptor signaling leading to activating the phosphorylation of TRPM channels and effects on other channels to intensify integral Ca2+-influx (fortified by endoplasmic reticulum Ca2+). ATP plus H2O2 are also required for branched-chain ketoacids (BCKAs); and partly for fatty acids (FAs) to secrete insulin, while BCKA or FA β-oxidation provide redox signaling from mitochondria, which proceeds by H2O2 diffusion or hypothetical SH relay via peroxiredoxin "redox kiss" to target proteins.
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Interplay among Oxidative Stress, Methylglyoxal Pathway and S-Glutathionylation. Antioxidants (Basel) 2020; 10:antiox10010019. [PMID: 33379155 PMCID: PMC7824032 DOI: 10.3390/antiox10010019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 12/17/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) are produced constantly inside the cells as a consequence of nutrient catabolism. The balance between ROS production and elimination allows to maintain cell redox homeostasis and biological functions, avoiding the occurrence of oxidative distress causing irreversible oxidative damages. A fundamental player in this fine balance is reduced glutathione (GSH), required for the scavenging of ROS as well as of the reactive 2-oxoaldehydes methylglyoxal (MGO). MGO is a cytotoxic compound formed constitutively as byproduct of nutrient catabolism, and in particular of glycolysis, detoxified in a GSH-dependent manner by the glyoxalase pathway consisting in glyoxalase I and glyoxalase II reactions. A physiological increase in ROS production (oxidative eustress, OxeS) is promptly signaled by the decrease of cellular GSH/GSSG ratio which can induce the reversible S-glutathionylation of key proteins aimed at restoring the redox balance. An increase in MGO level also occurs under oxidative stress (OxS) conditions probably due to several events among which the decrease in GSH level and/or the bottleneck of glycolysis caused by the reversible S-glutathionylation and inhibition of glyceraldehyde-3-phosphate dehydrogenase. In the present review, it is shown how MGO can play a role as a stress signaling molecule in response to OxeS, contributing to the coordination of cell metabolism with gene expression by the glycation of specific proteins. Moreover, it is highlighted how the products of MGO metabolism, S-D-lactoylglutathione (SLG) and D-lactate, which can be taken up and metabolized by mitochondria, could play important roles in cell response to OxS, contributing to cytosol-mitochondria crosstalk, cytosolic and mitochondrial GSH pools, energy production, and the restoration of the GSH/GSSG ratio. The role for SLG and glyoxalase II in the regulation of protein function through S-glutathionylation under OxS conditions is also discussed. Overall, the data reported here stress the need for further studies aimed at understanding what role the evolutionary-conserved MGO formation and metabolism can play in cell signaling and response to OxS conditions, the aberration of which may importantly contribute to the pathogenesis of diseases associated to elevated OxS.
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Silva-Rodrigues T, de-Souza-Ferreira E, Machado CM, Cabral-Braga B, Rodrigues-Ferreira C, Galina A. Hyperglycemia in a type 1 Diabetes Mellitus model causes a shift in mitochondria coupled-glucose phosphorylation and redox metabolism in rat brain. Free Radic Biol Med 2020; 160:796-806. [PMID: 32949665 DOI: 10.1016/j.freeradbiomed.2020.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 12/26/2022]
Abstract
Hyperglycemia associated with Diabetes Mellitus type 1 (DM1) comorbidity may cause severe complications in several tissues that lead to premature death. These dysfunctions are related, among others, to redox imbalances caused by the uncontrolled cellular levels of reactive oxygen species (ROS). Brain is potentially prone to develop diabetes complications because of its great susceptibility to oxidative stress. In addition to antioxidant enzymes, mitochondria-coupled hexokinase (mt-HK) plays an essential role in maintaining high flux of oxygen and glucose to control the mitochondrial membrane and redox potential in brain. This redox control is critical for healthy conditions in brain and in the pathophysiological progression of DM1. The mitochondrial and mt-HK contribution in this process is essential to understand the relationship between DM1 complications and the management of the cellular redox balance. Using a rat model of one month of hyperglycemia induced by a single administration intraperitoneally of streptozotocin, we showed in the present work that, in rat brain mitochondria, there is a specifically reduction of the mitochondrial complex I (CI) activity and an increase in the activity of the antioxidant enzyme thioredoxin reductase, which are related to decreased hydrogen peroxide generation, oxygen consumption and mt-HK coupled-to-OxPhos activity via mitochondrial CI. Surprisingly, DM1 increases respiratory parameters and mt-HK activity via mitochondrial complex II (CII). This way, for the first time, we provide evidence that early progression of hyperglycemia, in brain tissue, changes the coupling of glucose phosphorylation at the level of mitochondria by rearranging the oxidative machinery of brain mitochondria towards CII dependent electron harvest. In addition, DM1 increased the production of H2O2 by α-ketoglutarate dehydrogenase without causing oxidative stress. Finally, DM1 increased the oxidation status of PTEN and decreased the activation of NF-kB in DM1. These results indicate that this reorganization of glucose-oxygen-ROS axis in mitochondria may impact turnover of glucose, brain amino acids, redox and inflammatory signaling. In addition, this reorganization may be involved in early protection mechanisms against the development of cognitive degeneration and neurodegenerative disease, widely associated to mitochondrial CI deficits.
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Affiliation(s)
- Thaia Silva-Rodrigues
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Laboratory of Bioenergetics and Mitochondrial Phisiology, Av. Carlos Chagas Filho 373, Centro de Ciências da Saúde (CCS), Cidade Universitária, Rio de Janeiro, RJ, CEP: 21941902, Brazil.
| | - Eduardo de-Souza-Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Laboratory of Bioenergetics and Mitochondrial Phisiology, Av. Carlos Chagas Filho 373, Centro de Ciências da Saúde (CCS), Cidade Universitária, Rio de Janeiro, RJ, CEP: 21941902, Brazil
| | - Caio Mota Machado
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Laboratory of Bioenergetics and Mitochondrial Phisiology, Av. Carlos Chagas Filho 373, Centro de Ciências da Saúde (CCS), Cidade Universitária, Rio de Janeiro, RJ, CEP: 21941902, Brazil
| | - Bruno Cabral-Braga
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho 373, Centro de Ciências da Saúde (CCS)- Cidade Universitária, Rio de Janeiro, RJ, CEP: 21941902, Brazil
| | - Clara Rodrigues-Ferreira
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho 373, Centro de Ciências da Saúde (CCS)- Cidade Universitária, Rio de Janeiro, RJ, CEP: 21941902, Brazil
| | - Antonio Galina
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Laboratory of Bioenergetics and Mitochondrial Phisiology, Av. Carlos Chagas Filho 373, Centro de Ciências da Saúde (CCS), Cidade Universitária, Rio de Janeiro, RJ, CEP: 21941902, Brazil.
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Diabetic Retinopathy: The Role of Mitochondria in the Neural Retina and Microvascular Disease. Antioxidants (Basel) 2020; 9:antiox9100905. [PMID: 32977483 PMCID: PMC7598160 DOI: 10.3390/antiox9100905] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy (DR), a common chronic complication of diabetes mellitus and the leading cause of vision loss in the working-age population, is clinically defined as a microvascular disease that involves damage of the retinal capillaries with secondary visual impairment. While its clinical diagnosis is based on vascular pathology, DR is associated with early abnormalities in the electroretinogram, indicating alterations of the neural retina and impaired visual signaling. The pathogenesis of DR is complex and likely involves the simultaneous dysregulation of multiple metabolic and signaling pathways through the retinal neurovascular unit. There is evidence that microvascular disease in DR is caused in part by altered energetic metabolism in the neural retina and specifically from signals originating in the photoreceptors. In this review, we discuss the main pathogenic mechanisms that link alterations in neural retina bioenergetics with vascular regression in DR. We focus specifically on the recent developments related to alterations in mitochondrial metabolism including energetic substrate selection, mitochondrial function, oxidation-reduction (redox) imbalance, and oxidative stress, and critically discuss the mechanisms of these changes and their consequences on retinal function. We also acknowledge implications for emerging therapeutic approaches and future research directions to find novel mitochondria-targeted therapeutic strategies to correct bioenergetics in diabetes. We conclude that retinal bioenergetics is affected in the early stages of diabetes with consequences beyond changes in ATP content, and that maintaining mitochondrial integrity may alleviate retinal disease.
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Placenta-Derived Mesenchymal Stem Cells Restore the Ovary Function in an Ovariectomized Rat Model via an Antioxidant Effect. Antioxidants (Basel) 2020; 9:antiox9070591. [PMID: 32640638 PMCID: PMC7402146 DOI: 10.3390/antiox9070591] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress is one of the major etiologies of ovarian dysfunction, including premature ovarian failure (POF). Previous reports have demonstrated the therapeutic effects of human placenta-derived mesenchymal stem cells (PD-MSCs) in an ovariectomized rat model (OVX). However, their therapeutic mechanism in oxidative stress has not been reported. Therefore, we investigated to profile the exosome of serum and demonstrate the therapeutic effect of PD-MSCs transplantation for the ovary function. We established an OVX model by ovariectomy and PD-MSCs transplantation was conducted by intravenous injection. Additionally, various factors in the exosome were profiled by LC-MS analysis. As a result, the transplanted PD-MSCs were engrafted into the ovary and the existence of antioxidant factors in the exosome. A decreased expression of oxidative stress markers and increased expression of antioxidant markers were shown in the transplantation (Tx) in comparison to the non-transplantation group (NTx) (* p < 0.05). The apoptosis factors were decreased, and ovary function was improved in Tx in comparison to NTx (* p < 0.05). These results suggest that transplanted PD-MSCs restore the ovarian function in an OVX model via upregulated antioxidant factors. These findings offer new insights for further understanding of stem cell therapy for reproductive systems.
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Plecitá-Hlavatá L, Jabůrek M, Holendová B, Tauber J, Pavluch V, Berková Z, Cahová M, Schröder K, Brandes RP, Siemen D, Ježek P. Glucose-Stimulated Insulin Secretion Fundamentally Requires H 2O 2 Signaling by NADPH Oxidase 4. Diabetes 2020; 69:1341-1354. [PMID: 32245800 DOI: 10.2337/db19-1130] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/30/2020] [Indexed: 11/13/2022]
Abstract
NADPH facilitates glucose-stimulated insulin secretion (GSIS) in pancreatic islets (PIs) of β-cells through an as yet unknown mechanism. We found NADPH oxidase isoform 4 (NOX4) to be the main producer of cytosolic H2O2, which is essential for GSIS; an increase in ATP alone was insufficient for GSIS. The fast GSIS phase was absent from PIs from NOX4-null, β-cell-specific knockout mice (NOX4βKO) (though not from NOX2 knockout mice) and from NOX4-silenced or catalase-overexpressing INS-1E cells. Lentiviral NOX4 overexpression or H2O2 rescued GSIS in PIs from NOX4βKO mice. NOX4 silencing suppressed Ca2+ oscillations, and the patch-clamped KATP channel opened more frequently when glucose was high. Mitochondrial H2O2, decreasing upon GSIS, provided alternative redox signaling when 2-oxo-isocaproate or fatty acid oxidation formed superoxides through electron-transfer flavoprotein:Q-oxidoreductase. Unlike GSIS, such insulin secretion was blocked with mitochondrial antioxidant SkQ1. Both NOX4 knockout and NOX4βKO mice exhibited impaired glucose tolerance and peripheral insulin resistance. Thus, the redox signaling previously suggested to cause β-cells to self-check hypothetically induces insulin resistance when it is absent. In conclusion, increases in ATP and H2O2 constitute an essential signal that switches on insulin exocytosis for glucose and branched-chain oxoacids as secretagogues (it does so partially for fatty acids). Redox signaling could be impaired by cytosolic antioxidants; hence, those targeting mitochondria should be preferred for clinical applications to treat (pre)diabetes at any stage.
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Affiliation(s)
- Lydie Plecitá-Hlavatá
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Jabůrek
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Blanka Holendová
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Tauber
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vojtěch Pavluch
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Berková
- Institute of Clinical and Experimental Medicine, Prague, Czech Republic
| | - Monika Cahová
- Institute of Clinical and Experimental Medicine, Prague, Czech Republic
| | - Katrin Schröder
- Institut für Kardiovaskuläre Physiologie, Goethe-Universität, Frankfurt, Germany
| | - Ralf P Brandes
- Institut für Kardiovaskuläre Physiologie, Goethe-Universität, Frankfurt, Germany
| | - Detlef Siemen
- Klinik für Neurologie, Universität Magdeburg, Magdeburg, Germany
| | - Petr Ježek
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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Lennicke C, Cochemé HM. Redox signalling and ageing: insights from Drosophila. Biochem Soc Trans 2020; 48:367-377. [PMID: 32196546 PMCID: PMC7200633 DOI: 10.1042/bst20190052] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/23/2020] [Accepted: 02/25/2020] [Indexed: 12/12/2022]
Abstract
Ageing and age-related diseases are major challenges for the social, economic and healthcare systems of our society. Amongst many theories, reactive oxygen species (ROS) have been implicated as a driver of the ageing process. As by-products of aerobic metabolism, ROS are able to randomly oxidise macromolecules, causing intracellular damage that accumulates over time and ultimately leads to dysfunction and cell death. However, the genetic overexpression of enzymes involved in the detoxification of ROS or treatment with antioxidants did not generally extend lifespan, prompting a re-evaluation of the causal role for ROS in ageing. More recently, ROS have emerged as key players in normal cellular signalling by oxidising redox-sensitive cysteine residues within proteins. Therefore, while high levels of ROS may be harmful and induce oxidative stress, low levels of ROS may actually be beneficial as mediators of redox signalling. In this context, enhancing ROS production in model organisms can extend lifespan, with biological effects dependent on the site, levels, and specific species of ROS. In this review, we examine the role of ROS in ageing, with a particular focus on the importance of the fruit fly Drosophila as a powerful model system to study redox processes in vivo.
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Affiliation(s)
- Claudia Lennicke
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, U.K
- Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K
| | - Helena M. Cochemé
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, U.K
- Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, U.K
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