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Shannon CE, Bakewell T, Fourcaudot MJ, Ayala I, Smelter AA, Hinostroza EA, Romero G, Asmis M, Freitas Lima LC, Wallace M, Norton L. The mitochondrial pyruvate carrier regulates adipose glucose partitioning in female mice. Mol Metab 2024; 88:102005. [PMID: 39137831 PMCID: PMC11382204 DOI: 10.1016/j.molmet.2024.102005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/26/2024] [Accepted: 08/06/2024] [Indexed: 08/15/2024] Open
Abstract
OBJECTIVE The mitochondrial pyruvate carrier (MPC) occupies a critical node in intermediary metabolism, prompting interest in its utility as a therapeutic target for the treatment of obesity and cardiometabolic disease. Dysregulated nutrient metabolism in adipose tissue is a prominent feature of obesity pathophysiology, yet the functional role of adipose MPC has not been explored. We investigated whether the MPC shapes the adaptation of adipose tissue to dietary stress in female and male mice. METHODS The impact of pharmacological and genetic disruption of the MPC on mitochondrial pathways of triglyceride assembly (lipogenesis and glyceroneogenesis) was assessed in 3T3L1 adipocytes and murine adipose explants, combined with analyses of adipose MPC expression in metabolically compromised humans. Whole-body and adipose-specific glucose metabolism were subsequently investigated in male and female mice lacking adipocyte MPC1 (Mpc1AD-/-) and fed either standard chow, high-fat western style, or high-sucrose lipid restricted diets for 24 weeks, using a combination of radiolabeled tracers and GC/MS metabolomics. RESULTS Treatment with UK5099 or siMPC1 impaired the synthesis of lipids and glycerol-3-phosphate from pyruvate and blunted triglyceride accumulation in 3T3L1 adipocytes, whilst MPC expression in human adipose tissue was negatively correlated with indices of whole-body and adipose tissue metabolic dysfunction. Mature adipose explants from Mpc1AD-/- mice were intrinsically incapable of incorporating pyruvate into triglycerides. In vivo, MPC deletion restricted the incorporation of circulating glucose into adipose triglycerides, but only in female mice fed a zero fat diet, and this associated with sex-specific reductions in tricarboxylic acid cycle pool sizes and compensatory transcriptional changes in lipogenic and glycerol metabolism pathways. However, whole-body adiposity and metabolic health were preserved in Mpc1AD-/- mice regardless of sex, even under conditions of zero dietary fat. CONCLUSIONS These findings highlight the greater capacity for mitochondrially driven triglyceride assembly in adipose from female versus male mice and expose a reliance upon MPC-gated metabolism for glucose partitioning in female adipose under conditions of dietary lipid restriction.
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Affiliation(s)
- Christopher E Shannon
- UCD Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland; Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA.
| | - Terry Bakewell
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Marcel J Fourcaudot
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Iriscilla Ayala
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Annie A Smelter
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Edgar A Hinostroza
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Giovanna Romero
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Mara Asmis
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Leandro C Freitas Lima
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Martina Wallace
- UCD Conway Institute, School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Luke Norton
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA; Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA.
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Zhou Q, Cao T, Li F, Zhang M, Li X, Zhao H, Zhou Y. Mitochondria: a new intervention target for tumor invasion and metastasis. Mol Med 2024; 30:129. [PMID: 39179991 PMCID: PMC11344364 DOI: 10.1186/s10020-024-00899-4] [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: 06/08/2024] [Accepted: 08/14/2024] [Indexed: 08/26/2024] Open
Abstract
Mitochondria, responsible for cellular energy synthesis and signal transduction, intricately regulate diverse metabolic processes, mediating fundamental biological phenomena such as cell growth, aging, and apoptosis. Tumor invasion and metastasis, key characteristics of malignancies, significantly impact patient prognosis. Tumor cells frequently exhibit metabolic abnormalities in mitochondria, including alterations in metabolic dynamics and changes in the expression of relevant metabolic genes and associated signal transduction pathways. Recent investigations unveil further insights into mitochondrial metabolic abnormalities, revealing their active involvement in tumor cell proliferation, resistance to chemotherapy, and a crucial role in tumor cell invasion and metastasis. This paper comprehensively outlines the latest research advancements in mitochondrial structure and metabolic function. Emphasis is placed on summarizing the role of mitochondrial metabolic abnormalities in tumor invasion and metastasis, including alterations in the mitochondrial genome (mutations), activation of mitochondrial-to-nuclear signaling, and dynamics within the mitochondria, all intricately linked to the processes of tumor invasion and metastasis. In conclusion, the paper discusses unresolved scientific questions in this field, aiming to provide a theoretical foundation and novel perspectives for developing innovative strategies targeting tumor invasion and metastasis based on mitochondrial biology.
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Affiliation(s)
- Quanling Zhou
- Department of Pathophysiology, Zunyi Medical University, Zunyi Guizhou, 563000, China
- Department of Physics, Zunyi Medical University, Zunyi Guizhou, 563000, China
| | - Tingping Cao
- Department of Pathophysiology, Zunyi Medical University, Zunyi Guizhou, 563000, China
- Department of Physics, Zunyi Medical University, Zunyi Guizhou, 563000, China
| | - Fujun Li
- Department of Pathophysiology, Zunyi Medical University, Zunyi Guizhou, 563000, China
- Department of Physics, Zunyi Medical University, Zunyi Guizhou, 563000, China
| | - Ming Zhang
- Department of Physics, Zunyi Medical University, Zunyi Guizhou, 563000, China
| | - Xiaohui Li
- Department of Physics, Zunyi Medical University, Zunyi Guizhou, 563000, China
| | - Hailong Zhao
- Department of Pathophysiology, Zunyi Medical University, Zunyi Guizhou, 563000, China
| | - Ya Zhou
- Department of Pathophysiology, Zunyi Medical University, Zunyi Guizhou, 563000, China.
- Department of Physics, Zunyi Medical University, Zunyi Guizhou, 563000, China.
- Key Laboratory of Gene Detection and Therapy of Guizhou Province, Zunyi Guizhou, 563000, China.
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Hadfield CM, Walker JK, Arnatt C, McCommis KS. Computational structural prediction and chemical inhibition of the human mitochondrial pyruvate carrier protein heterodimer complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594520. [PMID: 39071381 PMCID: PMC11275797 DOI: 10.1101/2024.05.16.594520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
The mitochondrial pyruvate carrier (MPC) plays a role in numerous diseases including neurodegeneration, metabolically dependent cancers, and the development of insulin resistance. Several previous studies in genetic mouse models or with existing inhibitors suggest that inhibition of the MPC could be used as a viable therapeutic strategy in these diseases. However, the MPC's structure is unknown, making it difficult to screen for and develop therapeutically viable inhibitors. Currently known MPC inhibitors would make for poor drugs due to their poor pharmacokinetic properties, or in the case of the thiazolidinediones (TZDs), off-target specificity for peroxisome-proliferator activated receptor gamma (PPARγ) leads to unwanted side effects. In this study, we develop several structural models for the MPC heterodimer complex and investigate the chemical interactions required for the binding of these known inhibitors to MPC and PPARγ. Based on these models, the MPC most likely takes on outward-facing (OF) and inward-facing (IF) conformations during pyruvate transport, and inhibitors likely plug the carrier to inhibit pyruvate transport. Although some chemical interactions are similar between MPC and PPARγ binding, there is likely enough difference to reduce PPARγ specificity for future development of novel, more specific MPC inhibitors.
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Affiliation(s)
- Christy M Hadfield
- Edward A. Doisy Department of Biochemistry & Molecular Biology, Saint Louis University School of Medicine
| | - John K Walker
- Department of Pharmacology & Physiology, Saint Louis University School of Medicine
- Department of Chemistry, Saint Louis University
| | - Chris Arnatt
- Department of Pharmacology & Physiology, Saint Louis University School of Medicine
- Department of Chemistry, Saint Louis University
| | - Kyle S McCommis
- Edward A. Doisy Department of Biochemistry & Molecular Biology, Saint Louis University School of Medicine
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Bretscher H, O’Connor MB. Glycogen homeostasis and mtDNA expression require motor neuron to muscle TGFβ/Activin Signaling in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.600699. [PMID: 39131342 PMCID: PMC11312462 DOI: 10.1101/2024.06.25.600699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Maintaining metabolic homeostasis requires coordinated nutrient utilization between intracellular organelles and across multiple organ systems. Many organs rely heavily on mitochondria to generate (ATP) from glucose, or stored glycogen. Proteins required for ATP generation are encoded in both nuclear and mitochondrial DNA (mtDNA). We show that motoneuron to muscle signaling by the TGFβ/Activin family member Actβ positively regulates glycogen levels during Drosophila development. Remarkably, we find that levels of stored glycogen are unaffected by altering cytoplasmic glucose catabolism. Instead, Actβ loss reduces levels of mtDNA and nuclearly encoded genes required for mtDNA replication, transcription and translation. Direct RNAi mediated knockdown of these same nuclearly encoded mtDNA expression factors also results in decreased glycogen stores. Lastly, we find that expressing an activated form of the type I receptor Baboon in muscle restores both glycogen and mtDNA levels in actβ mutants, thereby confirming a direct link between Actβ signaling, glycogen homeostasis and mtDNA expression.
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Affiliation(s)
- Heidi Bretscher
- Department of Genetics, Cell Biology and Development University of Minnesota, Minneapolis, MN 55455
| | - Michael B. O’Connor
- Department of Genetics, Cell Biology and Development University of Minnesota, Minneapolis, MN 55455
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5
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Shannon CE, Bakewell T, Fourcaudot MJ, Ayala I, Romero G, Asmis M, Lima LCF, Wallace M, Norton L. Sex-dependent adipose glucose partitioning by the mitochondrial pyruvate carrier. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.11.593540. [PMID: 38798427 PMCID: PMC11118482 DOI: 10.1101/2024.05.11.593540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Objective The mitochondrial pyruvate carrier (MPC) occupies a critical node in intermediary metabolism, prompting interest in its utility as a therapeutic target for the treatment of obesity and cardiometabolic disease. Dysregulated nutrient metabolism in adipose tissue is a prominent feature of obesity pathophysiology, yet the functional role of adipose MPC has not been explored. We investigated whether the MPC shapes the adaptation of adipose tissue to dietary stress in female and male mice. Methods The impact of pharmacological and genetic disruption of the MPC on mitochondrial pathways of triglyceride assembly (lipogenesis and glyceroneogenesis) was assessed in 3T3L1 adipocytes and murine adipose explants, combined with analyses of adipose MPC expression in metabolically compromised humans. Whole-body and adipose-specific glucose metabolism were subsequently investigated in male and female mice lacking adipocyte MPC1 (Mpc1AD-/-) and fed either standard chow, high-fat western style, or high-sucrose lipid restricted diets for 24 weeks, using a combination of radiolabeled tracers and GC/MS metabolomics. Results Treatment with UK5099 or siMPC1 impaired the synthesis of lipids and glycerol-3-phosphate from pyruvate and blunted triglyceride accumulation in 3T3L1 adipocytes, whilst MPC expression in human adipose tissue was negatively correlated with indices of whole-body and adipose tissue metabolic dysfunction. Mature adipose explants from Mpc1AD-/- mice were intrinsically incapable of incorporating pyruvate into triglycerides. In vivo, MPC deletion restricted the incorporation of circulating glucose into adipose triglycerides, but only in female mice fed a zero fat diet, and this associated with sex-specific reductions in tricarboxylic acid cycle pool sizes and compensatory transcriptional changes in lipogenic and glycerol metabolism pathways. However, whole-body adiposity and metabolic health were preserved in Mpc1AD-/- mice regardless of sex, even under conditions of zero dietary fat. Conclusion These findings highlight the greater capacity for mitochondrially driven triglyceride assembly in adipose from female versus male mice and expose a reliance upon MPC-gated metabolism for glucose partitioning in female adipose under conditions of dietary lipid restriction.
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Affiliation(s)
- Christopher E Shannon
- UCD Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Terry Bakewell
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Marcel J Fourcaudot
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Iriscilla Ayala
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Giovanna Romero
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Mara Asmis
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Leandro C Freitas Lima
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Martina Wallace
- UCD Conway Institute, School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Luke Norton
- Diabetes Division, Department of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
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Maffioli E, Murtas G, Rabattoni V, Badone B, Tripodi F, Iannuzzi F, Licastro D, Nonnis S, Rinaldi AM, Motta Z, Sacchi S, Canu N, Tedeschi G, Coccetti P, Pollegioni L. Insulin and serine metabolism as sex-specific hallmarks of Alzheimer's disease in the human hippocampus. Cell Rep 2022; 40:111271. [PMID: 36070700 DOI: 10.1016/j.celrep.2022.111271] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 07/01/2022] [Accepted: 08/05/2022] [Indexed: 11/24/2022] Open
Abstract
Healthy aging is an ambitious aspiration for humans, but neurodegenerative disorders, such as Alzheimer's disease (AD), strongly affect quality of life. Using an integrated omics approach, we investigate alterations in the molecular composition of postmortem hippocampus samples of healthy persons and individuals with AD. Profound differences are apparent between control and AD male and female cohorts in terms of up- and downregulated metabolic pathways. A decrease in the insulin response is evident in AD when comparing the female with the male group. The serine metabolism (linked to the glycolytic pathway and generating the N-methyl-D-aspartate [NMDA] receptor coagonist D-serine) is also significantly modulated: the D-Ser/total serine ratio represents a way to counteract age-related cognitive decline in healthy men and during AD onset in women. These results show how AD changes and, in certain respects, almost reverses sex-specific proteomic and metabolomic profiles, highlighting how different pathophysiological mechanisms are active in men and women.
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Affiliation(s)
- Elisa Maffioli
- DIVAS, Department of Veterinary Medicine and Animal Science, University of Milano, 20121 Milano, Italy; CIMAINA, University of Milano, 20121 Milano, Italy
| | - Giulia Murtas
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
| | - Valentina Rabattoni
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
| | - Beatrice Badone
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milano, Italy
| | - Farida Tripodi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milano, Italy
| | - Filomena Iannuzzi
- Department of System Medicine, University of Rome "Tor Vergata," 00133 Rome, Italy
| | | | - Simona Nonnis
- DIVAS, Department of Veterinary Medicine and Animal Science, University of Milano, 20121 Milano, Italy; CIMAINA, University of Milano, 20121 Milano, Italy
| | - Anna Maria Rinaldi
- Department of System Medicine, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Zoraide Motta
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
| | - Silvia Sacchi
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
| | - Nadia Canu
- Department of System Medicine, University of Rome "Tor Vergata," 00133 Rome, Italy; Istituto di Biochimica e Biologia Cellulare (IBBC) CNR, 00015 Monterotondo Scalo, Italy.
| | - Gabriella Tedeschi
- DIVAS, Department of Veterinary Medicine and Animal Science, University of Milano, 20121 Milano, Italy; CIMAINA, University of Milano, 20121 Milano, Italy.
| | - Paola Coccetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milano, Italy.
| | - Loredano Pollegioni
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
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Bayazit MB, Jacovetti C, Cosentino C, Sobel J, Wu K, Brozzi F, Rodriguez-Trejo A, Stoll L, Guay C, Regazzi R. Small RNAs derived from tRNA fragmentation regulate the functional maturation of neonatal β cells. Cell Rep 2022; 40:111069. [PMID: 35830789 DOI: 10.1016/j.celrep.2022.111069] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/03/2022] [Accepted: 06/17/2022] [Indexed: 11/03/2022] Open
Abstract
tRNA-derived fragments (tRFs) are an emerging class of small non-coding RNAs with distinct cellular functions. Here, we studied the contribution of tRFs to the regulation of postnatal β cell maturation, a critical process that may lead to diabetes susceptibility in adulthood. We identified three tRFs abundant in neonatal rat islets originating from 5' halves (tiRNA-5s) of histidine and glutamate tRNAs. Their inhibition in these islets reduced β cell proliferation and insulin secretion. Mitochondrial respiration was also perturbed, fitting with the mitochondrial enrichment of nuclear-encoded tiRNA-5HisGTG and tiRNA-5GluCTC. Notably, tiRNA-5 inhibition reduced Mpc1, a mitochondrial pyruvate carrier whose knock down largely phenocopied tiRNA-5 inhibition. tiRNA-5HisGTG interactome revealed binding to Musashi-1, which was essential for the mitochondrial enrichment of tiRNA-5HisGTG. Finally, tiRNA-5s were dysregulated in the islets of diabetic and diabetes-prone animals. Altogether, tiRNA-5s represent a class of regulators of β cell maturation, and their deregulation in neonatal islets may lead to diabetes susceptibility in adulthood.
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Affiliation(s)
- Mustafa Bilal Bayazit
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Cécile Jacovetti
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Cristina Cosentino
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Jonathan Sobel
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Kejing Wu
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Flora Brozzi
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | | | - Lisa Stoll
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Claudiane Guay
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Romano Regazzi
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, 1005 Lausanne, Switzerland.
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Yiew NKH, Finck BN. The mitochondrial pyruvate carrier at the crossroads of intermediary metabolism. Am J Physiol Endocrinol Metab 2022; 323:E33-E52. [PMID: 35635330 PMCID: PMC9273276 DOI: 10.1152/ajpendo.00074.2022] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/04/2022] [Accepted: 05/18/2022] [Indexed: 11/22/2022]
Abstract
Pyruvate metabolism, a central nexus of carbon homeostasis, is an evolutionarily conserved process and aberrant pyruvate metabolism is associated with and contributes to numerous human metabolic disorders including diabetes, cancer, and heart disease. As a product of glycolysis, pyruvate is primarily generated in the cytosol before being transported into the mitochondrion for further metabolism. Pyruvate entry into the mitochondrial matrix is a critical step for efficient generation of reducing equivalents and ATP and for the biosynthesis of glucose, fatty acids, and amino acids from pyruvate. However, for many years, the identity of the carrier protein(s) that transported pyruvate into the mitochondrial matrix remained a mystery. In 2012, the molecular-genetic identification of the mitochondrial pyruvate carrier (MPC), a heterodimeric complex composed of protein subunits MPC1 and MPC2, enabled studies that shed light on the many metabolic and physiological processes regulated by pyruvate metabolism. A better understanding of the mechanisms regulating pyruvate transport and the processes affected by pyruvate metabolism may enable novel therapeutics to modulate mitochondrial pyruvate flux to treat a variety of disorders. Herein, we review our current knowledge of the MPC, discuss recent advances in the understanding of mitochondrial pyruvate metabolism in various tissue and cell types, and address some of the outstanding questions relevant to this field.
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Affiliation(s)
- Nicole K H Yiew
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, Missouri
| | - Brian N Finck
- Center for Human Nutrition, Washington University School of Medicine, St. Louis, Missouri
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Colca JR, Finck BN. Metabolic Mechanisms Connecting Alzheimer's and Parkinson's Diseases: Potential Avenues for Novel Therapeutic Approaches. Front Mol Biosci 2022; 9:929328. [PMID: 35782864 PMCID: PMC9243557 DOI: 10.3389/fmolb.2022.929328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's (AD) and Parkinson's Diseases (PD) are common neurodegenerative disorders growing in incidence and prevalence and for which there are no disease-modifying treatments. While there are considerable complexities in the presentations of these diseases, the histological pictures of these pathologies, as well as several rare genetic predispositions for each, point to the involvement of maladaptive protein processing and inflammation. Importantly, the common presentations of AD and PD are connected to aging and to dysmetabolism, including common co-diagnosis of metabolic syndrome or diabetes. Examination of anti-diabetic therapies in preclinical models and in some observational clinical studies have suggested effectiveness of the first generation insulin sensitizer pioglitazone in both AD and PD. Recently, the mitochondrial pyruvate carrier (MPC) was shown to be a previously unrecognized target of pioglitazone. New insulin sensitizers are in development that can be dosed to full engagement of this previously unappreciated mitochondrial target. Here we review molecular mechanisms that connect modification of pyruvate metabolism with known liabilities of AD and PD. The mechanisms involve modification of autophagy, inflammation, and cell differentiation in various cell types including neurons, glia, macrophages, and endothelium. These observations have implications for the understanding of the general pathology of neurodegeneration and suggest general therapeutic approaches to disease modification.
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Affiliation(s)
- Jerry R. Colca
- Metabolic Solutions Development Company, Western Michigan University, Kalamazoo, MI, United States
| | - Brian N. Finck
- Washington University School of Medicine, St. Louis, MO, United States
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10
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Zhang W, Wang C, Hu X, Lian Y, Ding C, Ming L. Inhibition of LDHA suppresses cell proliferation and increases mitochondrial apoptosis via the JNK signaling pathway in cervical cancer cells. Oncol Rep 2022; 47:77. [PMID: 35191522 PMCID: PMC8892607 DOI: 10.3892/or.2022.8288] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/28/2022] [Indexed: 11/08/2022] Open
Abstract
The Warburg effect or aerobic glycolysis is a hallmark of cancer. Lactate dehydrogenase (LDH), which catalyzes conversion of pyruvate into lactate, serves a critical role during Warburg effect. LDH A chain (LDHA), a member of the LDH family, is upregulated in multiple types of cancer and serves a vital role in tumor growth and progression. However, its expression and function in cervical cancer has not been characterized. The present study evaluated LDHA expression in The Cancer Genome Atlas database and found that LDHA was upregulated in cervical cancer compared with normal tissue. To clarify the role of LDHA in cervical cancer HeLa and SiHa cells, lentiviral shRNA was used to stably knockdown LDHA and oxamate, a small-molecule inhibitor of LDHA, was used to inhibit the activity of LDHA. Glucose uptake assay, lactate production measurement and ATP detection assay demonstrated LDHA inhibition notably decreased glucose consumption, lactate production and ATP levels in both HeLa and SiHa cells. Furthermore, the effect of LDHA inhibition on cell proliferation, cell cycle and apoptosis was investigated by MTT, BrdU incorporation, colony formation assay, flow cytometry and western blotting; LDHA knockdown or oxamate treatment led to decreased cell proliferation and increased apoptosis. Inhibition of LDHA induced G2/M cell cycle arrest and activated the mitochondrial apoptosis pathway. Mechanistically, the JNK signaling pathway was key for LDHA inhibition-mediated cell cycle arrest and apoptosis. Collectively, these results indicated that LDHA was involved in cervical cancer pathogenesis and may be a promising therapeutic target for treatment.
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Affiliation(s)
- Wenjing Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R China
| | - Cui Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R China
| | - Xiaomei Hu
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R China
| | - Yanzhen Lian
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R China
| | - Caili Ding
- Zhengzhou Hang Gang Ding Shi Medical Laboratory Co., Ltd., Zhengzhou, Henan 450000, P.R. China
| | - Liang Ming
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R Chin
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Mitochondrial pyruvate carrier inhibitors improve metabolic parameters in diet-induced obese mice. J Biol Chem 2021; 298:101554. [PMID: 34973337 PMCID: PMC8808181 DOI: 10.1016/j.jbc.2021.101554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 11/21/2022] Open
Abstract
The mitochondrial pyruvate carrier (MPC) is an inner mitochondrial membrane complex that plays a critical role in intermediary metabolism. Inhibition of the MPC, especially in liver, may have efficacy for treating type 2 diabetes mellitus. Herein, we examined the antidiabetic effects of zaprinast and 7ACC2, small molecules which have been reported to act as MPC inhibitors. Both compounds activated a bioluminescence resonance energy transfer–based MPC reporter assay (reporter sensitive to pyruvate) and potently inhibited pyruvate-mediated respiration in isolated mitochondria. Furthermore, zaprinast and 7ACC2 acutely improved glucose tolerance in diet-induced obese mice in vivo. Although some findings were suggestive of improved insulin sensitivity, hyperinsulinemic–euglycemic clamp studies did not detect enhanced insulin action in response to 7ACC2 treatment. Rather, our data suggest acute glucose-lowering effects of MPC inhibition may be due to suppressed hepatic gluconeogenesis. Finally, we used reporter sensitive to pyruvate to screen a chemical library of drugs and identified 35 potentially novel MPC modulators. Using available evidence, we generated a pharmacophore model to prioritize which hits to pursue. Our analysis revealed carsalam and six quinolone antibiotics, as well as 7ACC1, share a common pharmacophore with 7ACC2. We validated that these compounds are novel inhibitors of the MPC and suppress hepatocyte glucose production and demonstrated that one quinolone (nalidixic acid) improved glucose tolerance in obese mice. In conclusion, these data demonstrate the feasibility of therapeutic targeting of the MPC for treating diabetes and provide scaffolds that can be used to develop potent and novel classes of MPC inhibitors.
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Touaibia M, St-Coeur PD, Duff P, Faye DC, Pichaud N. 5-Benzylidene, 5-benzyl, and 3-benzylthiazolidine-2,4-diones as potential inhibitors of the mitochondrial pyruvate carrier: Effects on mitochondrial functions and survival in Drosophila melanogaster. Eur J Pharmacol 2021; 913:174627. [PMID: 34774497 DOI: 10.1016/j.ejphar.2021.174627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/29/2021] [Accepted: 11/08/2021] [Indexed: 01/17/2023]
Abstract
A series of thiazolidinediones (TZDs) were synthesized and screened for their effect on the mitochondrial respiration as well as on several mitochondrial respiratory system components of Drosophila melanogaster. Substituted and non-substituted 5-benzylidene and 5-benzylthiazolidine-2,4-diones were investigated. The effect of a substitution in position 3, at the nitrogen atom, of the thiozolidine heterocycle was also investigated. The designed TZDs were compared to UK5099, the most potent mitochondrial pyruvate carrier (MPC) inhibitor, in in vitro and in vivo tests. Compared to 5-benzylthiazolidine-2,4-diones 6-7 and 3-benzylthiazolidine-2,4-dione 8, 5-benzylidenethiazolidine-2,4-diones 2-5 showed more inhibitory capacity on mitochondrial respiration. 5-(4-Hydroxybenzylidene)thiazolidine-2,4-dione (3) and 5-(3-hydroxy-4-methoxybenzylidene)thiazolidine-2,4-dione (5) were among the best compounds that compared well with UK5099. Additionally, TZDs 3 and 5, showed no effects on the non-coupled respiration and weak effects on pathways using substrates such as proline, succinate, and G3P. 5-Benzylidenethiazolidine-2,4-dione 3 showed a positive effect on survival and lifespan when added to Drosophila standard and high fat diet. Interestingly, analog 3 completely reversed the effects of high fat diet on Drosophila longevity and induced metabolic changes which suggests an in vivo inhibition of MPC at the mitochondrial level.
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Affiliation(s)
- Mohamed Touaibia
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada.
| | | | - Patrick Duff
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | - Diene Codou Faye
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada
| | - Nicolas Pichaud
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada.
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Pretta A, Ziranu P, Puzzoni M, Lai E, Orsi G, Liscia N, Molinaro E, Mariani S, Riggi L, Rovesti G, Dubois M, Migliari M, Persano M, Saba G, Impera V, Musio F, Batzella E, Demurtas L, Pusceddu V, Astara G, Faloppi L, Casadei Gardini A, Andrikou K, Cascinu S, Scartozzi M. Retrospective survival analysis in patients with metastatic pancreatic ductal adenocarcinoma with insulin-treated type 2 diabetes mellitus. TUMORI JOURNAL 2021; 107:550-555. [PMID: 33243068 DOI: 10.1177/0300891620976945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION The association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated and the role of antidiabetic medications such as metformin has also been investigated. The objective of this study was to examine the association between insulin use and overall survival (OS) in patients with advanced PDAC and DM2. METHODS We retrospectively collected data from 164 patients, including an exploratory cohort of 96 patients from Medical Oncology Unit, University Hospital and University of Cagliari, Italy, and a validation cohort of 68 patients from Medical Oncology of Modena University Hospital. Patients had metastatic disease and received a first-line gemcitabine-based chemotherapy and, subsequently, a second-line fluoropyrimidines-based chemotherapy. We performed univariate analysis to evaluate correlation between long-term diabetes and overall survival. Then we performed multivariate analysis, adjusting for sex, metastatic sites, Eastern Cooperative Oncology Group Performance Status, Ca19.9 levels, N/L ratio, and lactate dehydrogenase levels at diagnosis, to confirm the independence of the variable. RESULTS In the exploratory cohort, DM2 was significantly associated with higher median OS at univariate analysis (16 vs 10 months; p = 0.004). This result was confirmed by validation cohort (11 months vs 6 months; p = 0.01). In multivariate analysis, insulin-treated patients compared with non diabetic patients showed a significantly increased survival of 4.6 months (p = 0.03). CONCLUSIONS Patients with insulin-treated metastatic PDAC showed better OS than non diabetic patients, as demonstrated by both cohorts. The correlation between OS and insulin-treated DM2 should be investigated further through a prospective clinical trial.
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Affiliation(s)
- Andrea Pretta
- Medical Oncology Unit, Sapienza University of Rome, Roma, Italy
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Pina Ziranu
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Marco Puzzoni
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Eleonora Lai
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Giulia Orsi
- Department of Oncology and Hematology, Division of Oncology, University of Modena and Reggio Emilia, Modena, Italy
| | - Nicole Liscia
- Medical Oncology Unit, Sapienza University of Rome, Roma, Italy
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Eleonora Molinaro
- Department of Oncology and Hematology, Division of Oncology, University of Modena and Reggio Emilia, Modena, Italy
| | - Stefano Mariani
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Laura Riggi
- Department of Oncology and Hematology, Division of Oncology, University of Modena and Reggio Emilia, Modena, Italy
| | - Giulia Rovesti
- Department of Oncology and Hematology, Division of Oncology, University of Modena and Reggio Emilia, Modena, Italy
| | - Marco Dubois
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Marco Migliari
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Mara Persano
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Giorgio Saba
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Valentino Impera
- Medical Oncology Unit, Sapienza University of Rome, Roma, Italy
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Francesca Musio
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Erich Batzella
- Department of Statistical Science, University of Padova, Padova, Veneto, Italy
| | - Laura Demurtas
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Valeria Pusceddu
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Giorgio Astara
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
| | - Luca Faloppi
- Department of Medical Oncology, Macerata General Hospital, Macerata, Italy
| | - Andrea Casadei Gardini
- Department of Oncology and Hematology, Division of Oncology, University of Modena and Reggio Emilia, Modena, Italy
| | - Kalliopi Andrikou
- Department of Oncology and Hematology, Division of Oncology, University of Modena and Reggio Emilia, Modena, Italy
| | - Stefano Cascinu
- IRCCS San Raffaele Scientific Institute Hospital, Milan, Italy
| | - Mario Scartozzi
- Medical Oncology Unit, University Hospital and University of Cagliari, Monserrato, Cagliari, Italy
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Veluthakal R, Thurmond DC. Emerging Roles of Small GTPases in Islet β-Cell Function. Cells 2021; 10:1503. [PMID: 34203728 PMCID: PMC8232272 DOI: 10.3390/cells10061503] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/08/2021] [Accepted: 06/08/2021] [Indexed: 12/16/2022] Open
Abstract
Several small guanosine triphosphatases (GTPases) from the Ras protein superfamily regulate glucose-stimulated insulin secretion in the pancreatic islet β-cell. The Rho family GTPases Cdc42 and Rac1 are primarily involved in relaying key signals in several cellular functions, including vesicle trafficking, plasma membrane homeostasis, and cytoskeletal dynamics. They orchestrate specific changes at each spatiotemporal region within the β-cell by coordinating with signal transducers, guanine nucleotide exchange factors (GEFs), GTPase-activating factors (GAPs), and their effectors. The Arf family of small GTPases is involved in vesicular trafficking (exocytosis and endocytosis) and actin cytoskeletal dynamics. Rab-GTPases regulate pre-exocytotic and late endocytic membrane trafficking events in β-cells. Several additional functions for small GTPases include regulating transcription factor activity and mitochondrial dynamics. Importantly, defects in several of these GTPases have been found associated with type 2 diabetes (T2D) etiology. The purpose of this review is to systematically denote the identities and molecular mechanistic steps in the glucose-stimulated insulin secretion pathway that leads to the normal release of insulin. We will also note newly identified defects in these GTPases and their corresponding regulatory factors (e.g., GDP dissociation inhibitors (GDIs), GEFs, and GAPs) in the pancreatic β-cells, which contribute to the dysregulation of metabolism and the development of T2D.
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Affiliation(s)
- Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope Beckman Research Institute, Duarte, CA 91010, USA
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope Beckman Research Institute, Duarte, CA 91010, USA
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15
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Kamm DR, Pyles KD, Sharpe MC, Healy LN, Colca JR, McCommis KS. Novel insulin sensitizer MSDC-0602K improves insulinemia and fatty liver disease in mice, alone and in combination with liraglutide. J Biol Chem 2021; 296:100807. [PMID: 34022222 PMCID: PMC8192871 DOI: 10.1016/j.jbc.2021.100807] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 01/04/2023] Open
Abstract
Insulin sensitizers and incretin mimetics are antidiabetic agents with vastly different mechanisms of action. Thiazolidinedione (TZD) insulin sensitizers are associated with weight gain, whereas glucagon-like peptide-1 receptor agonists can induce weight loss. We hypothesized that combination of a TZD insulin sensitizer and the glucagon-like peptide-1 receptor agonist liraglutide would more significantly improve mouse models of diabetes and nonalcoholic steatohepatitis (NASH). Diabetic db/db and MS-NASH mice were treated with the TZD MSDC-0602K by oral gavage, liraglutide (Lira) by s.c. injection, or combination 0602K+Lira. Lira slightly reduced body weight and modestly improved glycemia in db/db mice. Comparatively, 0602K-treated and 0602K+Lira-treated mice exhibited slight weight gain but completely corrected glycemia and improved glucose tolerance. 0602K reduced plasma insulin, whereas Lira further increased the hyperinsulinemia of db/db mice. Surprisingly, 0602K+Lira treatment reduced plasma insulin and C-peptide to the same extent as mice treated with 0602K alone. 0602K did not reduce glucose-stimulated insulin secretion in vivo, or in isolated islets, indicating the reduced insulinemia was likely compensatory to improved insulin sensitivity. In MS-NASH mice, both 0602K or Lira alone improved plasma alanine aminotransferase and aspartate aminotransferase, as well as liver histology, but more significant improvements were observed with 0602K+Lira treatment. 0602K or 0602K+Lira also increased pancreatic insulin content in both db/db and MS-NASH mice. In conclusion, MSDC-0602K corrected glycemia and reduced insulinemia when given alone, or in combination with Lira. However, 0602K+Lira combination more significantly improved glucose tolerance and liver histology, suggesting that this combination treatment may be an effective therapeutic strategy for diabetes and NASH.
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Affiliation(s)
- Dakota R Kamm
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Kelly D Pyles
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Martin C Sharpe
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Laura N Healy
- LNH Tox Path Consulting LLC, Newbury Park, California, USA
| | - Jerry R Colca
- Cirius Therapeutics, Kalamazoo, Michigan, USA; Cirius Therapeutics, San Diego, California, USA
| | - Kyle S McCommis
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA.
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16
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Fernandez-Caggiano M, Eaton P. Heart failure-emerging roles for the mitochondrial pyruvate carrier. Cell Death Differ 2021; 28:1149-1158. [PMID: 33473180 PMCID: PMC8027425 DOI: 10.1038/s41418-020-00729-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/14/2020] [Accepted: 12/27/2020] [Indexed: 01/30/2023] Open
Abstract
The mitochondrial pyruvate carrier (MPC) is the entry point for the glycolytic end-product pyruvate to the mitochondria. MPC activity, which is controlled by its abundance and post-translational regulation, determines whether pyruvate is oxidised in the mitochondria or metabolised in the cytosol. MPC serves as a crucial metabolic branch point that determines the fate of pyruvate in the cell, enabling metabolic adaptations during health, such as exercise, or as a result of disease. Decreased MPC expression in several cancers limits the mitochondrial oxidation of pyruvate and contributes to lactate accumulation in the cytosol, highlighting its role as a contributing, causal mediator of the Warburg effect. Pyruvate is handled similarly in the failing heart where a large proportion of it is reduced to lactate in the cytosol instead of being fully oxidised in the mitochondria. Several recent studies have found that the MPC abundance was also reduced in failing human and mouse hearts that were characterised by maladaptive hypertrophic growth, emulating the anabolic scenario observed in some cancer cells. In this review we discuss the evidence implicating the MPC as an important, perhaps causal, mediator of heart failure progression.
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Affiliation(s)
- Mariana Fernandez-Caggiano
- grid.4868.20000 0001 2171 1133The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ UK
| | - Philip Eaton
- grid.4868.20000 0001 2171 1133The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ UK
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17
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Ruiz-Iglesias A, Mañes S. The Importance of Mitochondrial Pyruvate Carrier in Cancer Cell Metabolism and Tumorigenesis. Cancers (Basel) 2021; 13:cancers13071488. [PMID: 33804985 PMCID: PMC8037430 DOI: 10.3390/cancers13071488] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 02/06/2023] Open
Abstract
Simple Summary The characteristic metabolic hallmark of cancer cells is the massive catabolism of glucose by glycolysis, even under aerobic conditions—the so-called Warburg effect. Although energetically unfavorable, glycolysis provides “building blocks” to sustain the unlimited growth of malignant cells. Aberrant glycolysis is also responsible for lactate accumulation and acidosis in the tumor milieu, which fosters hypoxia and immunosuppression. One of the mechanisms used by cancer cells to increase glycolytic flow is the negative regulation of the proteins that conform the mitochondrial pyruvate carrier (MPC) complex, which transports pyruvate into the mitochondrial matrix to be metabolized in the tricarboxylic acid (TCA) cycle. Evidence suggests that MPC downregulation in tumor cells impacts many aspects of tumorigenesis, including cancer cell-intrinsic (proliferation, invasiveness, stemness, resistance to therapy) and -extrinsic (angiogenesis, anti-tumor immune activity) properties. In many cancers, but not in all, MPC downregulation is associated with poor survival. MPC regulation is therefore central to tackling glycolysis in tumors. Abstract Pyruvate is a key molecule in the metabolic fate of mammalian cells; it is the crossroads from where metabolism proceeds either oxidatively or ends with the production of lactic acid. Pyruvate metabolism is regulated by many enzymes that together control carbon flux. Mitochondrial pyruvate carrier (MPC) is responsible for importing pyruvate from the cytosol to the mitochondrial matrix, where it is oxidatively phosphorylated to produce adenosine triphosphate (ATP) and to generate intermediates used in multiple biosynthetic pathways. MPC activity has an important role in glucose homeostasis, and its alteration is associated with diabetes, heart failure, and neurodegeneration. In cancer, however, controversy surrounds MPC function. In some cancers, MPC upregulation appears to be associated with a poor prognosis. However, most transformed cells undergo a switch from oxidative to glycolytic metabolism, the so-called Warburg effect, which, amongst other possibilities, is induced by MPC malfunction or downregulation. Consequently, impaired MPC function might induce tumors with strong proliferative, migratory, and invasive capabilities. Moreover, glycolytic cancer cells secrete lactate, acidifying the microenvironment, which in turn induces angiogenesis, immunosuppression, and the expansion of stromal cell populations supporting tumor growth. This review examines the latest findings regarding the tumorigenic processes affected by MPC.
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18
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Systemic Regulation of Host Energy and Oogenesis by Microbiome-Derived Mitochondrial Coenzymes. Cell Rep 2021; 34:108583. [PMID: 33406416 DOI: 10.1016/j.celrep.2020.108583] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/02/2020] [Accepted: 12/10/2020] [Indexed: 12/23/2022] Open
Abstract
Gut microbiota have been shown to promote oogenesis and fecundity, but the mechanistic basis of remote influence on oogenesis remained unknown. Here, we report a systemic mechanism of influence mediated by bacterial-derived supply of mitochondrial coenzymes. Removal of microbiota decreased mitochondrial activity and ATP levels in the whole-body and ovary, resulting in repressed oogenesis. Similar repression was caused by RNA-based knockdown of mitochondrial function in ovarian follicle cells. Reduced mitochondrial function in germ-free (GF) females was reversed by bacterial recolonization or supplementation of riboflavin, a precursor of FAD and FMN. Metabolomics analysis of GF females revealed a decrease in oxidative phosphorylation and FAD levels and an increase in metabolites that are degraded by FAD-dependent enzymes (e.g., amino and fatty acids). Riboflavin supplementation opposed this effect, elevating mitochondrial function, ATP, and oogenesis. These findings uncover a bacterial-mitochondrial axis of influence, linking gut bacteria with systemic regulation of host energy and reproduction.
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19
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Gaviraghi A, Aveiro Y, Carvalho SS, Rosa RS, Oliveira MP, Oliveira MF. Mechanical Permeabilization as a New Method for Assessment of Mitochondrial Function in Insect Tissues. Methods Mol Biol 2021; 2276:67-85. [PMID: 34060033 DOI: 10.1007/978-1-0716-1266-8_5] [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: 03/24/2023]
Abstract
Respirometry analysis is an effective technique to assess mitochondrial physiology. Insects are valuable biochemical models to understand metabolism and human diseases. Insect flight muscle and brain have been extensively used to explore mitochondrial function due to dissection feasibility and the low sample effort to allow oxygen consumption measurements. However, adequate plasma membrane permeabilization is required for substrates/modulators to reach mitochondria. Here, we describe a new method for study of mitochondrial physiology in insect tissues based on mechanical permeabilization as a fast and reliable method that do not require the use of detergents for chemical permeabilization of plasma membrane, while preserves mitochondrial integrity.
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Affiliation(s)
- Alessandro Gaviraghi
- Federal University of Rio de Janeiro, Institute of Medical Biochemistry Leopoldo de Meis, Rio De Janeiro, RJ, Brazil
| | - Yan Aveiro
- Federal University of Rio de Janeiro, Institute of Medical Biochemistry Leopoldo de Meis, Rio De Janeiro, RJ, Brazil
| | - Stephanie S Carvalho
- Federal University of Rio de Janeiro, Institute of Medical Biochemistry Leopoldo de Meis, Rio De Janeiro, RJ, Brazil
| | - Rodiesley S Rosa
- Federal University of Rio de Janeiro, Institute of Medical Biochemistry Leopoldo de Meis, Rio De Janeiro, RJ, Brazil
| | - Matheus P Oliveira
- Federal University of Rio de Janeiro, Institute of Medical Biochemistry Leopoldo de Meis, Rio De Janeiro, RJ, Brazil
| | - Marcus F Oliveira
- Federal University of Rio de Janeiro, Institute of Medical Biochemistry Leopoldo de Meis, Rio De Janeiro, RJ, Brazil.
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20
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Chareyron I, Christen S, Moco S, Valsesia A, Lassueur S, Dayon L, Wollheim CB, Santo Domingo J, Wiederkehr A. Augmented mitochondrial energy metabolism is an early response to chronic glucose stress in human pancreatic beta cells. Diabetologia 2020; 63:2628-2640. [PMID: 32960311 PMCID: PMC7641954 DOI: 10.1007/s00125-020-05275-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/04/2020] [Indexed: 01/15/2023]
Abstract
AIMS/HYPOTHESIS In islets from individuals with type 2 diabetes and in islets exposed to chronic elevated glucose, mitochondrial energy metabolism is impaired. Here, we studied early metabolic changes and mitochondrial adaptations in human beta cells during chronic glucose stress. METHODS Respiration and cytosolic ATP changes were measured in human islet cell clusters after culture for 4 days in 11.1 mmol/l glucose. Metabolomics was applied to analyse intracellular metabolite changes as a result of glucose stress conditions. Alterations in beta cell function were followed using insulin secretion assays or cytosolic calcium signalling after expression of the calcium probe YC3.6 specifically in beta cells of islet clusters. RESULTS At early stages of glucose stress, mitochondrial energy metabolism was augmented in contrast to the previously described mitochondrial dysfunction in beta cells from islets of diabetic donors. Following chronic glucose stress, mitochondrial respiration increased (by 52.4%, p < 0.001) and, as a consequence, the cytosolic ATP/ADP ratio in resting human pancreatic islet cells was elevated (by 27.8%, p < 0.05). Because of mitochondrial overactivation in the resting state, nutrient-induced beta cell activation was reduced. In addition, chronic glucose stress caused metabolic adaptations that resulted in the accumulation of intermediates of the glycolytic pathway, the pentose phosphate pathway and the TCA cycle; the most strongly augmented metabolite was glycerol 3-phosphate. The changes in metabolites observed are likely to be due to the inability of mitochondria to cope with continuous nutrient oversupply. To protect beta cells from chronic glucose stress, we inhibited mitochondrial pyruvate transport. Metabolite concentrations were partially normalised and the mitochondrial respiratory response to nutrients was markedly improved. Furthermore, stimulus-secretion coupling as assessed by cytosolic calcium signalling, was restored. CONCLUSION/INTERPRETATION We propose that metabolic changes and associated mitochondrial overactivation are early adaptations to glucose stress, and may reflect what happens as a result of poor blood glucose control. Inhibition of mitochondrial pyruvate transport reduces mitochondrial nutrient overload and allows beta cells to recover from chronic glucose stress. Graphical abstract.
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Affiliation(s)
- Isabelle Chareyron
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
- Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Stefan Christen
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
| | - Sofia Moco
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
| | - Armand Valsesia
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
| | - Steve Lassueur
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
| | - Loïc Dayon
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
- Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Claes B Wollheim
- Department of Cell Physiology and Metabolism, University Medical Center, Geneva, Switzerland
| | - Jaime Santo Domingo
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland
| | - Andreas Wiederkehr
- Nestlé Institute of Health Sciences, Nestlé Research, EPFL Innovation Park, Lausanne, Switzerland.
- Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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21
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McCommis KS, Kovacs A, Weinheimer CJ, Shew TM, Koves TR, Ilkayeva OR, Kamm DR, Pyles KD, King MT, Veech RL, DeBosch BJ, Muoio DM, Gross RW, Finck BN. Nutritional modulation of heart failure in mitochondrial pyruvate carrier-deficient mice. Nat Metab 2020; 2:1232-1247. [PMID: 33106690 PMCID: PMC7957960 DOI: 10.1038/s42255-020-00296-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 09/10/2020] [Indexed: 01/04/2023]
Abstract
The myocardium is metabolically flexible; however, impaired flexibility is associated with cardiac dysfunction in conditions including diabetes and heart failure. The mitochondrial pyruvate carrier (MPC) complex, composed of MPC1 and MPC2, is required for pyruvate import into the mitochondria. Here we show that MPC1 and MPC2 expression is downregulated in failing human and mouse hearts. Mice with cardiac-specific deletion of Mpc2 (CS-MPC2-/-) exhibited normal cardiac size and function at 6 weeks old, but progressively developed cardiac dilation and contractile dysfunction, which was completely reversed by a high-fat, low-carbohydrate ketogenic diet. Diets with higher fat content, but enough carbohydrate to limit ketosis, also improved heart failure, while direct ketone body provisioning provided only minor improvements in cardiac remodelling in CS-MPC2-/- mice. An acute fast also improved cardiac remodelling. Together, our results reveal a critical role for mitochondrial pyruvate use in cardiac function, and highlight the potential of dietary interventions to enhance cardiac fat metabolism to prevent or reverse cardiac dysfunction and remodelling in the setting of MPC deficiency.
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Affiliation(s)
- Kyle S McCommis
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA.
| | - Attila Kovacs
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Carla J Weinheimer
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Trevor M Shew
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Timothy R Koves
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA
| | - Olga R Ilkayeva
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA
| | - Dakota R Kamm
- Department of Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Kelly D Pyles
- Department of Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - M Todd King
- Laboratory of Metabolic Control, National Institute on Alcohol Abuse and Alcoholism, National Institute of Health, Bethesda, MD, USA
| | - Richard L Veech
- Laboratory of Metabolic Control, National Institute on Alcohol Abuse and Alcoholism, National Institute of Health, Bethesda, MD, USA
| | - Brian J DeBosch
- Departments of Pediatrics and Cell Biology & Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Deborah M Muoio
- Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC, USA
| | - Richard W Gross
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Chemistry, Washington University, St. Louis, MO, USA
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
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Role of the Mitochondrial Pyruvate Carrier in the Occurrence of Metabolic Inflexibility in Drosophila melanogaster Exposed to Dietary Sucrose. Metabolites 2020; 10:metabo10100411. [PMID: 33066485 PMCID: PMC7602203 DOI: 10.3390/metabo10100411] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/01/2020] [Accepted: 10/10/2020] [Indexed: 01/12/2023] Open
Abstract
Excess dietary carbohydrates are linked to dysregulation of metabolic pathways converging to mitochondria and metabolic inflexibility. Here, we determined the role of the mitochondrial pyruvate carrier (MPC) in the occurrence of this metabolic inflexibility in wild-type (WT) and MPC1-deficient (MPC1def) flies that were exposed to diets with different sucrose concentrations for 15–25 days (Standard Diet: SD, Medium-Sucrose Diet: MSD, and High-Sucrose Diet: HSD). Our results showed that MPC1def flies had lower mitochondrial respiration rates than WT flies on the SD and MSD. However, when exposed to the HSD, WT flies displayed decreased mitochondrial respiration rates compared to MPC1def flies. WT flies exposed to the HSD also displayed increased proline contribution and slightly decreased MPC1 expression. Surprisingly, when fed the MSD and the HSD, few metabolites were altered in WT flies whereas MPC1def flies display significant accumulation of glycogen, glucose, fructose, lactate, and glycerol. Overall, this suggests that metabolic inflexibility starts to occur in WT flies after 15–25 days of exposure to the HSD whereas the MPC1def flies display metabolic inflexibility independently of the diet provided. This study thus highlights the involvement of MPC as an essential protein in Drosophila to maintain proper metabolic homeostasis during changes in dietary resources.
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Simard C, Lebel A, Allain EP, Touaibia M, Hebert-Chatelain E, Pichaud N. Metabolic Characterization and Consequences of Mitochondrial Pyruvate Carrier Deficiency in Drosophila melanogaster. Metabolites 2020; 10:metabo10090363. [PMID: 32899962 PMCID: PMC7570025 DOI: 10.3390/metabo10090363] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/24/2020] [Accepted: 09/03/2020] [Indexed: 01/31/2023] Open
Abstract
In insect, pyruvate is generally the predominant oxidative substrate for mitochondria. This metabolite is transported inside mitochondria via the mitochondrial pyruvate carrier (MPC), but whether and how this transporter controls mitochondrial oxidative capacities in insects is still relatively unknown. Here, we characterize the importance of pyruvate transport as a metabolic control point for mitochondrial substrate oxidation in two genotypes of an insect model, Drosophila melanogaster, differently expressing MPC1, an essential protein for the MPC function. We evaluated the kinetics of pyruvate oxidation, mitochondrial oxygen consumption, metabolic profile, activities of metabolic enzymes, and climbing abilities of wild-type (WT) flies and flies harboring a deficiency in MPC1 (MPC1def). We hypothesized that MPC1 deficiency would cause a metabolic reprogramming that would favor the oxidation of alternative substrates. Our results show that the MPC1def flies display significantly reduced climbing capacity, pyruvate-induced oxygen consumption, and enzymatic activities of pyruvate kinase, alanine aminotransferase, and citrate synthase. Moreover, increased proline oxidation capacity was detected in MPC1def flies, which was associated with generally lower levels of several metabolites, and particularly those involved in amino acid catabolism such as ornithine, citrulline, and arginosuccinate. This study therefore reveals the flexibility of mitochondrial substrate oxidation allowing Drosophila to maintain cellular homeostasis.
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Affiliation(s)
- Chloé Simard
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada; (C.S.); (A.L.); (M.T.)
| | - Andréa Lebel
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada; (C.S.); (A.L.); (M.T.)
| | | | - Mohamed Touaibia
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada; (C.S.); (A.L.); (M.T.)
| | - Etienne Hebert-Chatelain
- Department of Biology, Université de Moncton, Moncton, NB E1A 3E9, Canada;
- Canada Research Chair in Mitochondrial Signaling and Physiopathology, Moncton, NB E1A 3E9, Canada
| | - Nicolas Pichaud
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada; (C.S.); (A.L.); (M.T.)
- Correspondence:
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24
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Buchanan JL, Taylor EB. Mitochondrial Pyruvate Carrier Function in Health and Disease across the Lifespan. Biomolecules 2020; 10:biom10081162. [PMID: 32784379 PMCID: PMC7464753 DOI: 10.3390/biom10081162] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 12/25/2022] Open
Abstract
As a nodal mediator of pyruvate metabolism, the mitochondrial pyruvate carrier (MPC) plays a pivotal role in many physiological and pathological processes across the human lifespan, from embryonic development to aging-associated neurodegeneration. Emerging research highlights the importance of the MPC in diverse conditions, such as immune cell activation, cancer cell stemness, and dopamine production in Parkinson’s disease models. Whether MPC function ameliorates or contributes to disease is highly specific to tissue and cell type. Cell- and tissue-specific differences in MPC content and activity suggest that MPC function is tightly regulated as a mechanism of metabolic, cellular, and organismal control. Accordingly, recent studies on cancer and diabetes have identified protein–protein interactions, post-translational processes, and transcriptional factors that modulate MPC function. This growing body of literature demonstrates that the MPC and other mitochondrial carriers comprise a versatile and dynamic network undergirding the metabolism of health and disease.
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Affiliation(s)
- Jane L. Buchanan
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA;
| | - Eric B. Taylor
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA;
- Holden Comprehensive Cancer Center, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Fraternal Order of Eagles Diabetes Research Center (FOEDRC), University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA 52240, USA
- Correspondence:
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25
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The Multifaceted Pyruvate Metabolism: Role of the Mitochondrial Pyruvate Carrier. Biomolecules 2020; 10:biom10071068. [PMID: 32708919 PMCID: PMC7407832 DOI: 10.3390/biom10071068] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/09/2020] [Accepted: 07/14/2020] [Indexed: 12/17/2022] Open
Abstract
Pyruvate, the end product of glycolysis, plays a major role in cell metabolism. Produced in the cytosol, it is oxidized in the mitochondria where it fuels the citric acid cycle and boosts oxidative phosphorylation. Its sole entry point into mitochondria is through the recently identified mitochondrial pyruvate carrier (MPC). In this review, we report the latest findings on the physiology of the MPC and we discuss how a dysfunctional MPC can lead to diverse pathologies, including neurodegenerative diseases, metabolic disorders, and cancer.
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26
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Zhu H, Wan H, Wu L, Li Q, Liu S, Duan S, Huang Z, Zhang C, Zhang B, Xing C, Yuan Y. Mitochondrial pyruvate carrier: a potential target for diabetic nephropathy. BMC Nephrol 2020; 21:274. [PMID: 32664896 PMCID: PMC7362444 DOI: 10.1186/s12882-020-01931-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/06/2020] [Indexed: 12/19/2022] Open
Abstract
Background Mitochondrial dysfunction contributes to the pathogenesis of diabetic nephropathy (DN). Mitochondrial pyruvate carrier 1 (MPC1) and mitochondrial pyruvate carrier 2 (MPC2) play a bottleneck role in the transport of pyruvate into mitochondrial across the mitochondrial inner membrane. A previous study showed that increasing mitochondrial pyruvate carrier content might ameliorate diabetic kidney disease in db/db mice. However, the expression status of MPC1 and MPC2 in patients with DN is unclear. Methods Patients with primary glomerulonephropathy (PGN, n = 30), PGN with diabetes mellitus (PGN-DM, n = 30) and diabetic nephropathy (DN, n = 30) were included. MPC1 and MPC2 protein levels were examined by immunohistochemistry. The expression of MPC in different groups was evaluated by the Kruskal-Wallis test. Spearman’s rank correlation was performed for correlation analysis between MPC levels and clinical factors. Results Both MPC1 and MPC2 were localized in renal tubules. Levels of MPC1 and MPC2 were lower in DN patients than in PGN patients and in PGN patients with DM, whereas there were no differences in MPC1 and MPC2 levels among DN stage II to stage IV. Moreover, both MPC1 and MPC2 levels were significantly correlated with serum creatinine, BUN and eGFR in patients with DN, whereas no analogous trend was observed in nondiabetic kidney disease. Conclusions Our study indicated that MPC localized in renal tubules, which were significantly decreased in DN. MPC was associated with clinical features, especially those representing renal functions.
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Affiliation(s)
- Huanhuan Zhu
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Huiting Wan
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Lin Wu
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Qing Li
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Simeng Liu
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Suyan Duan
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Zhimin Huang
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Chengning Zhang
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Bo Zhang
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China
| | - Changying Xing
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China.
| | - Yanggang Yuan
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, 300 Guangzhou Road, Nanjing, 210029, Jiangsu Province, P. R. of China.
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27
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Wisidagama DR, Thummel CS. Regulation of Drosophila Intestinal Stem Cell Proliferation by Enterocyte Mitochondrial Pyruvate Metabolism. G3 (BETHESDA, MD.) 2019; 9:3623-3630. [PMID: 31488514 PMCID: PMC6829144 DOI: 10.1534/g3.119.400633] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/02/2019] [Indexed: 12/16/2022]
Abstract
Multiple signaling pathways in the adult Drosophila enterocyte sense cellular damage or stress and signal to intestinal stem cells (ISCs) to undergo proliferation and differentiation, thereby maintaining intestinal homeostasis. Here we show that misregulation of mitochondrial pyruvate metabolism in enterocytes can stimulate ISC proliferation and differentiation. Our studies focus on the Mitochondrial Pyruvate Carrier (MPC), which is an evolutionarily-conserved protein complex that resides in the inner mitochondrial membrane and transports cytoplasmic pyruvate into the mitochondrial matrix. Loss of MPC function in enterocytes induces Unpaired cytokine expression, which activates the JAK/STAT pathway in ISCs, promoting their proliferation. Upd3 and JNK signaling are required in enterocytes for ISC proliferation, indicating that this reflects a canonical non-cell autonomous damage response. Disruption of lactate dehydrogenase in enterocytes has no effect on ISC proliferation but it suppresses the proliferative response to a loss of enterocyte MPC function, suggesting that lactate contributes to this pathway. These studies define an important role for cellular pyruvate metabolism in differentiated enterocytes to maintain stem cell proliferation rates.
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Affiliation(s)
- Dona R Wisidagama
- Department of Human Genetics, University of Utah School of Medicine, 15 North 2030 East Room 5100, Salt Lake City UT 84112-5330, USA
| | - Carl S Thummel
- Department of Human Genetics, University of Utah School of Medicine, 15 North 2030 East Room 5100, Salt Lake City UT 84112-5330, USA
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28
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Tavoulari S, Thangaratnarajah C, Mavridou V, Harbour ME, Martinou JC, Kunji ER. The yeast mitochondrial pyruvate carrier is a hetero-dimer in its functional state. EMBO J 2019; 38:e100785. [PMID: 30979775 PMCID: PMC6517818 DOI: 10.15252/embj.2018100785] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 03/13/2019] [Accepted: 03/20/2019] [Indexed: 02/02/2023] Open
Abstract
The mitochondrial pyruvate carrier (MPC) is critical for cellular homeostasis, as it is required in central metabolism for transporting pyruvate from the cytosol into the mitochondrial matrix. MPC has been implicated in many diseases and is being investigated as a drug target. A few years ago, small membrane proteins, called MPC1 and MPC2 in mammals and Mpc1, Mpc2 and Mpc3 in yeast, were proposed to form large protein complexes responsible for this function. However, the MPC complexes have never been isolated and their composition, oligomeric state and functional properties have not been defined. Here, we identify the functional unit of MPC from Saccharomyces cerevisiae In contrast to earlier hypotheses, we demonstrate that MPC is a hetero-dimer, not a multimeric complex. When not engaged in hetero-dimers, the yeast Mpc proteins can also form homo-dimers that are, however, inactive. We show that the earlier described substrate transport properties and inhibitor profiles are embodied by the hetero-dimer. This work provides a foundation for elucidating the structure of the functional complex and the mechanism of substrate transport and inhibition.
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Affiliation(s)
- Sotiria Tavoulari
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | | | - Vasiliki Mavridou
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Michael E Harbour
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | | | - Edmund Rs Kunji
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
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29
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Zou H, Chen Q, Zhang A, Wang S, Wu H, Yuan Y, Wang S, Yu J, Luo M, Wen X, Cui W, Fu W, Yu R, Chen L, Zhang M, Lan H, Zhang X, Xie Q, Jin G, Xu C. MPC1 deficiency accelerates lung adenocarcinoma progression through the STAT3 pathway. Cell Death Dis 2019; 10:148. [PMID: 30770798 PMCID: PMC6377639 DOI: 10.1038/s41419-019-1324-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 11/30/2018] [Accepted: 01/07/2019] [Indexed: 12/14/2022]
Abstract
Mitochondrial pyruvate carrier 1 (MPC1), a key factor that controls pyruvate transportation in the mitochondria, is known to be frequently dysregulated in tumor initiation and progression. However, the clinical relevance and potential molecular mechanisms of MPC1 in lung adenocarcinoma (LAC) progression remain to be illustrated. Herein, MPC1 was lowly expressed in LAC tissues and significantly associated with favorable survival of patients with LAC. Functionally, MPC1 markedly suppressed stemness, invasion, and migration in vitro and spreading growth of LAC cells in vivo. Further study revealed that MPC1 could interact with mitochondrial signal transducer and activator of transcription 3 (mito-STAT3), disrupting the distribution of STAT3 and reducing cytoplasmic signal transducer and activator of transcription 3 (cyto-STAT3) as well as its phosphorylation, while the activation of cyto-STAT3 by IL-6 reversed the attenuated malignant progression in MPC1-overexpression LAC cells. Collectively, we reveal that MPC1/STAT3 axis plays an important role in the progression of LAC, and our work may promote the development of new therapeutic strategies for LAC.
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Affiliation(s)
- Hongbo Zou
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.,Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Oncology, Third Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qian Chen
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China
| | - Anmei Zhang
- Department of Oncology, Xinqiao Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Songtao Wang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.,Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Oncology, Chengdu Military General Hospital, Chengdu, China
| | - Hong Wu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.,Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Ye Yuan
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China
| | - Shuang Wang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.,Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jing Yu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.,Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Oncology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Mao Luo
- Department of Dermatology, Chongqing Yubei District People's Hospital, Chongqing, China
| | - Xianmei Wen
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China
| | - Wei Cui
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Wenjuan Fu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China
| | - Ruilian Yu
- Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Lin Chen
- Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Ming Zhang
- Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Haitao Lan
- Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Xia Zhang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China
| | - Qichao Xie
- Department of Oncology, Third Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guoxiang Jin
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.
| | - Chuan Xu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), and Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China. .,Department of Oncology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
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30
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Regulation of Carbohydrate Energy Metabolism in Drosophila melanogaster. Genetics 2018; 207:1231-1253. [PMID: 29203701 DOI: 10.1534/genetics.117.199885] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/02/2017] [Indexed: 02/08/2023] Open
Abstract
Carbohydrate metabolism is essential for cellular energy balance as well as for the biosynthesis of new cellular building blocks. As animal nutrient intake displays temporal fluctuations and each cell type within the animal possesses specific metabolic needs, elaborate regulatory systems are needed to coordinate carbohydrate metabolism in time and space. Carbohydrate metabolism is regulated locally through gene regulatory networks and signaling pathways, which receive inputs from nutrient sensors as well as other pathways, such as developmental signals. Superimposed on cell-intrinsic control, hormonal signaling mediates intertissue information to maintain organismal homeostasis. Misregulation of carbohydrate metabolism is causative for many human diseases, such as diabetes and cancer. Recent work in Drosophila melanogaster has uncovered new regulators of carbohydrate metabolism and introduced novel physiological roles for previously known pathways. Moreover, genetically tractable Drosophila models to study carbohydrate metabolism-related human diseases have provided new insight into the mechanisms of pathogenesis. Due to the high degree of conservation of relevant regulatory pathways, as well as vast possibilities for the analysis of gene-nutrient interactions and tissue-specific gene function, Drosophila is emerging as an important model system for research on carbohydrate metabolism.
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31
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Simard CJ, Pelletier G, Boudreau LH, Hebert-Chatelain E, Pichaud N. Measurement of Mitochondrial Oxygen Consumption in Permeabilized Fibers of Drosophila Using Minimal Amounts of Tissue. J Vis Exp 2018. [PMID: 29683457 DOI: 10.3791/57376] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The fruit fly, Drosophila melanogaster, represents an emerging model for the study of metabolism. Indeed, drosophila have structures homologous to human organs, possess highly conserved metabolic pathways and have a relatively short lifespan that allows the study of different fundamental mechanisms in a short period of time. It is, however, surprising that one of the mechanisms essential for cellular metabolism, the mitochondrial respiration, has not been thoroughly investigated in this model. It is likely because the measure of the mitochondrial respiration in Drosophila usually requires a very large number of individuals and the results obtained are not highly reproducible. Here, a method allowing the precise measurement of mitochondrial oxygen consumption using minimal amounts of tissue from Drosophila is described. In this method, the thoraxes are dissected and permeabilized both mechanically with sharp forceps and chemically with saponin, allowing different compounds to cross the cell membrane and modulate the mitochondrial respiration. After permeabilization, a protocol is performed to evaluate the capacity of the different complexes of the electron transport system (ETS) to oxidize different substrates, as well as their response to an uncoupler and to several inhibitors. This method presents many advantages compared to methods using mitochondrial isolations, as it is more physiologically relevant because the mitochondria are still interacting with the other cellular components and the mitochondrial morphology is conserved. Moreover, sample preparations are faster, and the results obtained are highly reproducible. By combining the advantages of Drosophila as a model for the study of metabolism with the evaluation of mitochondrial respiration, important new insights can be unveiled, especially when the flies are experiencing different environmental or pathophysiological conditions.
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Affiliation(s)
- Chloé J Simard
- Département de chimie et biochimie, Université de Moncton
| | | | - Luc H Boudreau
- Département de chimie et biochimie, Université de Moncton
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32
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Chen Y, McCommis KS, Ferguson D, Hall AM, Harris CA, Finck BN. Inhibition of the Mitochondrial Pyruvate Carrier by Tolylfluanid. Endocrinology 2018; 159:609-621. [PMID: 29126303 PMCID: PMC5774852 DOI: 10.1210/en.2017-00695] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/01/2017] [Indexed: 12/20/2022]
Abstract
Several recent studies have suggested that compounds known as endocrine-disrupting chemicals (EDCs) can promote obesity by serving as ligands for nuclear receptors, including the peroxisome proliferator-activated receptor γ (PPARγ) and the glucocorticoid receptor (GR). Thiazolidinedione insulin sensitizers, which act as ligands for PPARγ, also interact with and regulate the activity of the mitochondrial pyruvate carrier (MPC). We evaluated whether several EDCs might also affect MPC activity. Most of the EDCs evaluated did not acutely affect pyruvate metabolism. However, the putative endocrine disruptors tributyltin (TBT) and tolylfluanid (TF) acutely and markedly suppressed pyruvate metabolism in isolated mitochondria. Using mitochondria isolated from brown adipose tissue in mice with adipocyte-specific deletion of the MPC2 protein, we determined that the effect of TF on pyruvate metabolism required MPC2, whereas TBT did not. We attempted to determine whether the obesogenic effects of TF might involve MPC2 in adipose tissue. However, we were unable to replicate the published effects of TF on weight gain and adipose tissue gene expression in wild-type or fat-specific MPC2 knockout mice. Treatment with TF modestly enhanced adipogenic gene expression in vitro but had no effect on GR activation or phosphorylation in cultured cells. These data suggest that TF may affect mitochondrial pyruvate metabolism via the MPC complex but also call into question whether this compound affects GR activity and is obesogenic in mice.
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Affiliation(s)
- Yana Chen
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Kyle S McCommis
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Daniel Ferguson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Angela M Hall
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Charles A Harris
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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33
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Shi TT, Yang FY, Liu C, Cao X, Lu J, Zhang XL, Yuan MX, Chen C, Yang JK. Angiotensin-converting enzyme 2 regulates mitochondrial function in pancreatic β-cells. Biochem Biophys Res Commun 2017; 495:860-866. [PMID: 29128354 DOI: 10.1016/j.bbrc.2017.11.055] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 11/08/2017] [Indexed: 12/12/2022]
Abstract
Mitochondrial metabolism plays an essential role in the regulation of insulin release and glucose homeostasis. Evidence demonstrated that the angiotensin-converting enzyme 2 (ACE2) participates in the regulation of glucose metabolism, however, its role in mitochondrial metabolism remains unclear. The purpose of our study was to determine if ACE2 can regulate mitochondrial function in pancreatic β-cells. We found that ACE2 over-expression restored glucose-stimulated insulin secretion (GSIS) and mitochondrial membrane potential (MMP) in the presence of H2O2 in INS-1 cells. PCR array demonstrated that ACE2 over-expression up-regulated 67 mitochondria-related genes in INS-1 cells. In pancreatic islets, ACE2 ablation attenuated intracellular calcium influx with a decrease in GSIS. Ace2-/y mice islets exhibited impaired mitochondrial respiration and lower production of ATP, along with decreased expression of genes involved in mitochondrial oxidation. In islets from db/db mice, ACE2 over-expression increased intracellular calcium influx and restored impaired mitochondrial oxidation, potentially causing an increase in GSIS. These results shed light on the potential roles of ACE2 in mitochondrial metabolism, moreover, may improve our understanding of diabetes.
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Affiliation(s)
- Ting-Ting Shi
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Fang-Yuan Yang
- Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Chang Liu
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Xi Cao
- Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Jing Lu
- Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Xue-Lian Zhang
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Ming-Xia Yuan
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jin-Kui Yang
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; Beijing Key Laboratory of Diabetes Research and Care, Beijing 100730, China.
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Vigueira PA, McCommis KS, Hodges WT, Schweitzer GG, Cole SL, Oonthonpan L, Taylor EB, McDonald WG, Kletzien RF, Colca JR, Finck BN. The beneficial metabolic effects of insulin sensitizers are not attenuated by mitochondrial pyruvate carrier 2 hypomorphism. Exp Physiol 2017; 102:985-999. [PMID: 28597936 DOI: 10.1113/ep086380] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/06/2017] [Indexed: 12/24/2022]
Abstract
NEW FINDINGS What is the central question of this study? The antidiabetic effects of thiazolidinedione (TZD) drugs may be mediated in part by a molecular interaction with the constituent proteins of the mitochondrial pyruvate carrier complex (MPC1 and MPC2). We examined the ability of a mutant mouse strain expressing an N-terminal truncation of MPC2 (Mpc2Δ16 mice) to respond to TZD treatment. What is the main finding and its importance? The response of Mpc2Δ16 mice to TZD treatment was not significantly different from that of wild-type C57BL6/J control animals, suggesting that the 16 N-terminal amino acids of MPC2 are dispensable for the effects of TZD treatment. Rosiglitazone and pioglitazone are thiazolidinedione (TZD) compounds that have been used clinically as insulin-sensitizing drugs and are generally believed to mediate their effects via activation of the peroxisome proliferator-activated receptor γ (PPARγ). Recent work has shown that it is possible to synthesize TZD compounds with potent insulin-sensitizing effects and markedly diminished affinity for PPARγ. Both clinically used TZDs and investigational PPARγ-sparing TZDs, such as MSDC-0602, interact with the mitochondrial pyruvate carrier (MPC) and inhibit its activity. The MPC complex is composed of two proteins, MPC1 and MPC2. Herein, we used mice expressing a hypomorphic MPC2 protein missing 16 amino acids in the N-terminus (Mpc2Δ16 mice) to determine the effects of these residues in mediating the insulin-sensitizing effects of TZDs in diet-induced obese mice. We found that both pioglitazone and MSDC-0602 elicited their beneficial metabolic effects, including improvement in glucose tolerance, attenuation of hepatic steatosis, reduction of adipose tissue inflammation and stimulation of adipocyte browning, in both wild-type and Mpc2Δ16 mice after high-fat diet feeding. In addition, truncation of MPC2 failed to attenuate the interaction between TZDs and the MPC in a bioluminescence resonance energy transfer-based assay or to affect the suppression of pyruvate-stimulated respiration in cells. Collectively, these data suggest that the interaction between TZDs and MPC2 is not affected by loss of the N-terminal 16 amino acids nor are these residues required for the insulin-sensitizing effects of these compounds.
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Affiliation(s)
- Patrick A Vigueira
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Kyle S McCommis
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Wesley T Hodges
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - George G Schweitzer
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Serena L Cole
- Metabolic Solutions Development Company, Kalamazoo, MI, 49007, USA
| | - Lalita Oonthonpan
- Department of Biochemistry and Fraternal Order of the Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52240, USA
| | - Eric B Taylor
- Department of Biochemistry and Fraternal Order of the Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52240, USA
| | | | - Rolf F Kletzien
- Metabolic Solutions Development Company, Kalamazoo, MI, 49007, USA
| | - Jerry R Colca
- Metabolic Solutions Development Company, Kalamazoo, MI, 49007, USA
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
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35
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Taylor EB. Functional Properties of the Mitochondrial Carrier System. Trends Cell Biol 2017; 27:633-644. [PMID: 28522206 DOI: 10.1016/j.tcb.2017.04.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/16/2017] [Accepted: 04/18/2017] [Indexed: 11/28/2022]
Abstract
The mitochondrial carrier system (MCS) transports small molecules between mitochondria and the cytoplasm. It is integral to the core mitochondrial function to regulate cellular chemistry by metabolism. The mammalian MCS comprises the transporters of the 53-member canonical SLC25A family and a lesser number of identified noncanonical transporters. The recent discovery and investigations of the mitochondrial pyruvate carrier (MPC) illustrate the diverse effects a single mitochondrial carrier may exert on cellular function. However, the transport selectivities of many carriers remain unknown, and most have not been functionally investigated in mammalian cells. The mechanisms coordinating their function as a unified system remain undefined. Increased accessibility to molecular genetic and metabolomic technologies now greatly enables investigation of the MCS. Continued investigation of the MCS may reveal how mitochondria encode complex regulatory information within chemical thermodynamic gradients. This understanding may enable precision modulation of cellular chemistry to counteract the dysmetabolism inherent in disease.
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Affiliation(s)
- Eric B Taylor
- Department of Biochemistry, Fraternal Order of the Eagles Diabetes Center, Holden Comprehensive Cancer Center, Abboud Cardiovascular Research Center, Pappajohn Biomedical Discovery Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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McCommis KS, Hodges WT, Brunt EM, Nalbantoglu ILK, McDonald WG, Holley C, Fujiwara H, Schaffer JE, Colca JR, Finck BN. Targeting the mitochondrial pyruvate carrier attenuates fibrosis in a mouse model of nonalcoholic steatohepatitis. Hepatology 2017; 65:1543-1556. [PMID: 28027586 PMCID: PMC5397348 DOI: 10.1002/hep.29025] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/30/2016] [Accepted: 12/22/2016] [Indexed: 12/30/2022]
Abstract
Diseases of the liver related to metabolic syndrome have emerged as the most common and undertreated hepatic ailments. The cause of nonalcoholic fatty liver disease is the aberrant accumulation of lipid in hepatocytes, though the mechanisms whereby this leads to hepatocyte dysfunction, death, and hepatic fibrosis are still unclear. Insulin-sensitizing thiazolidinediones have shown efficacy in treating nonalcoholic steatohepatitis (NASH), but their widespread use is constrained by dose-limiting side effects thought to be due to activation of the peroxisome proliferator-activated receptor γ. We sought to determine whether a next-generation thiazolidinedione with markedly diminished ability to activate peroxisome proliferator-activated receptor γ (MSDC-0602) would retain its efficacy for treating NASH in a rodent model. We also determined whether some or all of these beneficial effects would be mediated through an inhibitory interaction with the mitochondrial pyruvate carrier 2 (MPC2), which was recently identified as a mitochondrial binding site for thiazolidinediones, including MSDC-0602. We found that MSDC-0602 prevented and reversed liver fibrosis and suppressed expression of markers of stellate cell activation in livers of mice fed a diet rich in trans-fatty acids, fructose, and cholesterol. Moreover, mice with liver-specific deletion of MPC2 were protected from development of NASH on this diet. Finally, MSDC-0602 directly reduced hepatic stellate cell activation in vitro, and MSDC-0602 treatment or hepatocyte MPC2 deletion also limited stellate cell activation indirectly by affecting secretion of exosomes from hepatocytes. CONCLUSION Collectively, these data demonstrate the effectiveness of MSDC-0602 for attenuating NASH in a rodent model and suggest that targeting hepatic MPC2 may be an effective strategy for pharmacologic development. (Hepatology 2017;65:1543-1556).
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Affiliation(s)
- Kyle S. McCommis
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Wesley T. Hodges
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Elizabeth M. Brunt
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - ILKe Nalbantoglu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | | | - Christopher Holley
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Hideji Fujiwara
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Jean E. Schaffer
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Jerry R. Colca
- Metabolic Solutions Development Company, Kalamazoo, MI 49007
| | - Brian N. Finck
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
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