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Rezaei S, Timani KA, He JJ. Metformin Treatment Leads to Increased HIV Transcription and Gene Expression through Increased CREB Phosphorylation and Recruitment to the HIV LTR Promoter. Aging Dis 2024; 15:831-850. [PMID: 37450926 PMCID: PMC10917544 DOI: 10.14336/ad.2023.0705] [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: 05/19/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023] Open
Abstract
Antiretroviral therapy has effectively suppressed HIV infection and replication and prolonged the lifespan of HIV-infected individuals. In the meantime, various complications including type 2 diabetes associated with the long-term antiviral therapy have shown steady increases. Metformin has been the front-line anti-hyperglycemic drug of choice and the most widely prescribed medication for the treatment of type 2 diabetes. However, little is known about the effects of Metformin on HIV infection and replication. In this study, we showed that Metformin treatment enhanced HIV gene expression and transcription in HIV-transfected 293T and HIV-infected Jurkat and human PBMC. Moreover, we demonstrated that Metformin treatment resulted in increased CREB expression and phosphorylation, and TBP expression. Furthermore, we showed that Metformin treatment increased the recruitment of phosphorylated CREB and TBP to the HIV LTR promoter. Lastly, we showed that inhibition of CREB phosphorylation/activation significantly abrogated Metformin-enhanced HIV gene expression. Taken together, these results demonstrated that Metformin treatment increased HIV transcription, gene expression, and production through increased CREB phosphorylation and recruitment to the HIV LTR promoter. These findings may help design the clinical management plan and HIV cure strategy of using Metformin to treat type 2 diabetes, a comorbidity with an increasing prevalence, in people living with HIV.
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Affiliation(s)
- Sahar Rezaei
- Department of Microbiology and Immunology, Rosalind Franklin University, Chicago Medical School, North Chicago, IL 60064, USA.
- Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL 60064, USA.
- School of Graduate and Postdoctoral Studies, Rosalind Franklin University, North Chicago, IL 60064, USA.
| | - Khalid A Timani
- Department of Microbiology and Immunology, Rosalind Franklin University, Chicago Medical School, North Chicago, IL 60064, USA.
- Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL 60064, USA.
- School of Graduate and Postdoctoral Studies, Rosalind Franklin University, North Chicago, IL 60064, USA.
| | - Johnny J He
- Department of Microbiology and Immunology, Rosalind Franklin University, Chicago Medical School, North Chicago, IL 60064, USA.
- Center for Cancer Cell Biology, Immunology and Infection, Rosalind Franklin University, North Chicago, IL 60064, USA.
- School of Graduate and Postdoctoral Studies, Rosalind Franklin University, North Chicago, IL 60064, USA.
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2
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Maurer J, Zhao X, Irmler M, Gudiksen A, Pilmark NS, Li Q, Goj T, Beckers J, Hrabě de Angelis M, Birkenfeld AL, Peter A, Lehmann R, Pilegaard H, Karstoft K, Xu G, Weigert C. Redox state and altered pyruvate metabolism contribute to a dose-dependent metformin-induced lactate production of human myotubes. Am J Physiol Cell Physiol 2023; 325:C1131-C1143. [PMID: 37694284 PMCID: PMC10635655 DOI: 10.1152/ajpcell.00186.2023] [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: 05/04/2023] [Revised: 09/01/2023] [Accepted: 09/01/2023] [Indexed: 09/12/2023]
Abstract
Metformin-induced glycolysis and lactate production can lead to acidosis as a life-threatening side effect, but slight increases in blood lactate levels in a physiological range were also reported in metformin-treated patients. However, how metformin increases systemic lactate concentrations is only partly understood. Because human skeletal muscle has a high capacity to produce lactate, the aim was to elucidate the dose-dependent regulation of metformin-induced lactate production and the potential contribution of skeletal muscle to blood lactate levels under metformin treatment. This was examined by using metformin treatment (16-776 μM) of primary human myotubes and by 17 days of metformin treatment in humans. As from 78 µM, metformin induced lactate production and secretion and glucose consumption. Investigating the cellular redox state by mitochondrial respirometry, we found metformin to inhibit the respiratory chain complex I (776 µM, P < 0.01) along with decreasing the [NAD+]:[NADH] ratio (776 µM, P < 0.001). RNA sequencing and phospho-immunoblot data indicate inhibition of pyruvate oxidation mediated through phosphorylation of the pyruvate dehydrogenase (PDH) complex (39 µM, P < 0.01). On the other hand, in human skeletal muscle, phosphorylation of PDH was not altered by metformin. Nonetheless, blood lactate levels were increased under metformin treatment (P < 0.05). In conclusion, the findings suggest that metformin-induced inhibition of pyruvate oxidation combined with altered cellular redox state shifts the equilibrium of the lactate dehydrogenase (LDH) reaction leading to a dose-dependent lactate production in primary human myotubes.NEW & NOTEWORTHY Metformin shifts the equilibrium of lactate dehydrogenase (LDH) reaction by low dose-induced phosphorylation of pyruvate dehydrogenase (PDH) resulting in inhibition of pyruvate oxidation and high dose-induced increase in NADH, which explains the dose-dependent lactate production of differentiated human skeletal muscle cells.
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Affiliation(s)
- Jennifer Maurer
- Department for Diagnostic Laboratory Medicine, Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
| | - Xinjie Zhao
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Munich, Neuherberg, Germany
| | - Anders Gudiksen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Nanna S Pilmark
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Qi Li
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China
| | - Thomas Goj
- Department for Diagnostic Laboratory Medicine, Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
| | - Johannes Beckers
- Institute of Experimental Genetics, Helmholtz Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Chair of Experimental Genetics, Technical University of Munich, Freising, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, Helmholtz Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Chair of Experimental Genetics, Technical University of Munich, Freising, Germany
| | - Andreas L Birkenfeld
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Munich, University of Tübingen, Tübingen, Germany
- Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
| | - Andreas Peter
- Department for Diagnostic Laboratory Medicine, Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Munich, University of Tübingen, Tübingen, Germany
| | - Rainer Lehmann
- Department for Diagnostic Laboratory Medicine, Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Munich, University of Tübingen, Tübingen, Germany
| | - Henriette Pilegaard
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Karstoft
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark
- Department of Clinical Pharmacology, Bispebjerg and Fredriksberg Hospital, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Guowang Xu
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China
| | - Cora Weigert
- Department for Diagnostic Laboratory Medicine, Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Munich, University of Tübingen, Tübingen, Germany
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3
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Dutta S, Shah RB, Singhal S, Dutta SB, Bansal S, Sinha S, Haque M. Metformin: A Review of Potential Mechanism and Therapeutic Utility Beyond Diabetes. Drug Des Devel Ther 2023; 17:1907-1932. [PMID: 37397787 PMCID: PMC10312383 DOI: 10.2147/dddt.s409373] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/10/2023] [Indexed: 07/04/2023] Open
Abstract
Metformin has been designated as one of the most crucial first-line therapeutic agents in the management of type 2 diabetes mellitus. Primarily being an antihyperglycemic agent, metformin also has a plethora of pleiotropic effects on various systems and processes. It acts majorly by activating AMPK (Adenosine Monophosphate-Activated Protein Kinase) in the cells and reducing glucose output from the liver. It also decreases advanced glycation end products and reactive oxygen species production in the endothelium apart from regulating the glucose and lipid metabolism in the cardiomyocytes, hence minimizing the cardiovascular risks. Its anticancer, antiproliferative and apoptosis-inducing effects on malignant cells might prove instrumental in the malignancy of organs like the breast, kidney, brain, ovary, lung, and endometrium. Preclinical studies have also shown some evidence of metformin's neuroprotective role in Parkinson's disease, Alzheimer's disease, multiple sclerosis and Huntington's disease. Metformin exerts its pleiotropic effects through varied pathways of intracellular signalling and exact mechanism in the majority of them remains yet to be clearly defined. This article has extensively reviewed the therapeutic benefits of metformin and the details of its mechanism for a molecule of boon in various conditions like diabetes, prediabetes, obesity, polycystic ovarian disease, metabolic derangement in HIV, various cancers and aging.
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Affiliation(s)
- Siddhartha Dutta
- Department of Pharmacology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Rima B Shah
- Department of Pharmacology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Shubha Singhal
- Department of Pharmacology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Sudeshna Banerjee Dutta
- Department of Medical Surgical Nursing, Shri Anand Institute of Nursing, Rajkot, Gujarat, 360005, India
| | - Sumit Bansal
- Department of Anaesthesiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Susmita Sinha
- Department of Physiology, Khulna City Medical College and Hospital, Khulna, Bangladesh
| | - Mainul Haque
- Unit of Pharmacology, Faculty of Medicine and Defence Health, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Kuala Lumpur, 57000, Malaysia
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4
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Effect of metformin on intact mitochondria from liver and brain: Concept revisited. Eur J Pharmacol 2022; 931:175177. [DOI: 10.1016/j.ejphar.2022.175177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 07/07/2022] [Accepted: 07/25/2022] [Indexed: 11/18/2022]
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Pavlovic K, Krako Jakovljevic N, Isakovic AM, Ivanovic T, Markovic I, Lalic NM. Therapeutic vs. Suprapharmacological Metformin Concentrations: Different Effects on Energy Metabolism and Mitochondrial Function in Skeletal Muscle Cells in vitro. Front Pharmacol 2022; 13:930308. [PMID: 35873556 PMCID: PMC9299382 DOI: 10.3389/fphar.2022.930308] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/16/2022] [Indexed: 11/30/2022] Open
Abstract
Metformin is an oral antidiabetic agent that has been widely used in clinical practice for over 60 years, and is currently the most prescribed antidiabetic drug worldwide. However, the molecular mechanisms of metformin action in different tissues are still not completely understood. Although metformin-induced inhibition of mitochondrial respiratory chain Complex I and activation of AMP-activated protein kinase have been observed in many studies, published data is inconsistent. Furthermore, metformin concentrations used for in vitro studies and their pharmacological relevance are a common point of debate. The aim of this study was to explore the effects of different metformin concentrations on energy metabolism and activity of relevant signaling pathways in C2C12 muscle cells in vitro. In order to determine if therapeutic metformin concentrations have an effect on skeletal muscle cells, we used micromolar metformin concentrations (50 µM), and compared the effects with those of higher, millimolar concentrations (5 mM), that have already been established to affect mitochondrial function and AMPK activity. We conducted all experiments in conditions of high (25 mM) and low glucose (5.5 mM) concentration, in order to discern the role of glucose availability on metformin action. According to our results, micromolar metformin treatment did not cause Complex I inhibition nor AMPK activation. Also, cells cultured in low glucose medium were more sensitive to Complex I inhibition, mitochondrial membrane depolarization and AMPK activation by millimolar metformin, but cells cultured in high glucose medium were more prone to induction of ROS production. In conclusion, even though suprapharmacological metformin concentrations cause Complex I inhibition and AMPK activation in skeletal muscle cells in vitro, therapeutic concentrations cause no such effect. This raises the question if these mechanisms are relevant for therapeutic effects of metformin in skeletal muscle.
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Affiliation(s)
- Kasja Pavlovic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Center of Serbia, Belgrade, Serbia
| | - Nina Krako Jakovljevic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Center of Serbia, Belgrade, Serbia
| | - Andjelka M Isakovic
- Faculty of Medicine, Institute of Medical and Clinical Biochemistry, University of Belgrade, Belgrade, Serbia
| | - Tijana Ivanovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ivanka Markovic
- Faculty of Medicine, Institute of Medical and Clinical Biochemistry, University of Belgrade, Belgrade, Serbia
| | - Nebojsa M Lalic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Center of Serbia, Belgrade, Serbia
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6
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Wang Y, Lu H, Sun L, Chen X, Wei H, Suo C, Feng J, Yuan M, Shen S, Jia W, Wang Y, Zhang H, Li Z, Zhong X, Gao P. Metformin sensitises hepatocarcinoma cells to methotrexate by targeting dihydrofolate reductase. Cell Death Dis 2021; 12:902. [PMID: 34601503 PMCID: PMC8487431 DOI: 10.1038/s41419-021-04199-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/26/2021] [Accepted: 09/16/2021] [Indexed: 12/01/2022]
Abstract
Metformin, the first-line drug for type II diabetes, has recently been considered an anticancer agent. However, the molecular target and underlying mechanism of metformin's anti-cancer effects remain largely unclear. Herein, we report that metformin treatment increases the sensitivity of hepatocarcinoma cells to methotrexate (MTX) by suppressing the expression of the one-carbon metabolism enzyme DHFR. We show that the combination of metformin and MTX blocks nucleotide metabolism and thus effectively inhibits cell cycle progression and tumorigenesis. Mechanistically, metformin not only transcriptionally represses DHFR via E2F4 but also promotes lysosomal degradation of the DHFR protein. Notably, metformin dramatically increases the response of patient-derived hepatocarcinoma organoids to MTX without obvious toxicity to organoids derived from normal liver tissue. Taken together, our findings identify an important role for DHFR in the suppressive effects of metformin on therapeutic resistance, thus revealing a therapeutically targetable potential vulnerability in hepatocarcinoma.
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Affiliation(s)
- Yinghui Wang
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Hui Lu
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Linchong Sun
- Guangzhou First People's Hospital, School of Medicine and Institutes for Life Sciences, South China University of Technology, Guangzhou, China
| | - Xin Chen
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, China
- Suzhou Hospital of Anhui Medical University, Suzhou, China
| | - Haoran Wei
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Caixia Suo
- Guangzhou First People's Hospital, School of Medicine and Institutes for Life Sciences, South China University of Technology, Guangzhou, China
| | - Junru Feng
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Mengqiu Yuan
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China
| | - Shengqi Shen
- Guangdong Provincial Institute of Geriatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Weidong Jia
- Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, China
| | - Ying Wang
- Guangzhou First People's Hospital, School of Medicine and Institutes for Life Sciences, South China University of Technology, Guangzhou, China
| | - Huafeng Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China.
| | - Zijun Li
- Guangdong Provincial Institute of Geriatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xiuying Zhong
- Guangzhou First People's Hospital, School of Medicine and Institutes for Life Sciences, South China University of Technology, Guangzhou, China.
| | - Ping Gao
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, China.
- Guangzhou First People's Hospital, School of Medicine and Institutes for Life Sciences, South China University of Technology, Guangzhou, China.
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7
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Kurlovics J, Zake DM, Zaharenko L, Berzins K, Klovins J, Stalidzans E. Metformin Transport Rates Between Plasma and Red Blood Cells in Humans. Clin Pharmacokinet 2021; 61:133-142. [PMID: 34309806 PMCID: PMC8761711 DOI: 10.1007/s40262-021-01058-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2021] [Indexed: 11/30/2022]
Abstract
Background Metformin has been used for the treatment of type 2 diabetes for over 60 years; however, its mechanism of pharmacological action is not fully clear. Different hypotheses exist regarding metformin distribution and redistribution mechanisms between plasma and erythrocytes/red blood cells (RBCs). Objective We aimed to test the hypothesis that the metformin distribution between plasma and RBC occurs via concentration difference-driven passive transport and estimated transport rate coefficient values based on metformin concentration time series in plasma and RBCs from in vivo studies. Methods An ordinary differential equation (ODE) system with two compartments was used to describe diffusion-based passive transport between plasma and RBCs. Metformin concentration time series in plasma and RBCs of 35 individuals were used for metformin transport parametrization. Plasma concentration has been approximated by biexponential decline. Results A single passive transport coefficient, k = 0.044 ± 0.014 (h–1), can be applied, describing the uptake and release transport rate versus the linear equation v = k × (Mpl − MRBC), where Mpl is the metformin concentration in plasma and MRBC is the metformin concentration in RBCs. Conclusions Our research suggests that passive transport can explain metformin distribution dynamics between plasma and RBCs because transport speed is proportional to the metformin concentration difference and independent of the transport direction. Concentration difference-driven passive transport can explain the mechanism of faster metformin distribution to RBCs the first few hours after administration, and faster release and domination of the redistribution transport rate after metformin concentration in plasma becomes smaller than in RBCs. Supplementary Information The online version contains supplementary material available at 10.1007/s40262-021-01058-2.
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Affiliation(s)
- Janis Kurlovics
- Computational Systems Biology Group, Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia. .,Division of Pharmaceutical Chemistry and Technology, University of Helsinki, Helsinki, Finland.
| | - Darta Maija Zake
- Computational Systems Biology Group, Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia.,Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | - Kristaps Berzins
- Computational Systems Biology Group, Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
| | - Janis Klovins
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Egils Stalidzans
- Computational Systems Biology Group, Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia.,Latvian Biomedical Research and Study Centre, Riga, Latvia
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Vial G, Lamarche F, Cottet‐Rousselle C, Hallakou‐Bozec S, Borel A, Fontaine E. The mechanism by which imeglimin inhibits gluconeogenesis in rat liver cells. Endocrinol Diabetes Metab 2021; 4:e00211. [PMID: 33855213 PMCID: PMC8029524 DOI: 10.1002/edm2.211] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/09/2020] [Accepted: 11/14/2020] [Indexed: 01/05/2023] Open
Abstract
Aims To understand the mechanism by which imeglimin (a new oral hypoglycemic agent whose phase 3 development program in Japan has now been completed) decreases hepatic glucose production. Materials and methods We compared the effect of imeglimin and metformin on glucose production, ATP/ADP ratio, oxygen consumption rate, mitochondrial redox potential and membrane potential in primary rat hepatocytes. Results We found that both imeglimin and metformin dose-dependently decreased glucose production and the ATP/ADP ratio. Moreover, they both increased mitochondrial redox potential (assessed by mitochondrial NAD(P)H fluorescence) and decreased membrane potential (assessed by TMRM fluorescence). However, contrary to metformin, which inhibits mitochondrial Complex I, imeglimin did not decrease the oxygen consumption rate in intact cells. By measuring the oxygen consumption of in situ respiratory chain as a function of the concentration of NADH, we observed that imeglimin decreased the affinity of NADH for the respiratory chain but did not affect its Vmax (ie competitive inhibition) whereas metformin decreased both the Vmax and the affinity (ie uncompetitive inhibition). Conclusions We conclude that imeglimin induces a kinetic constraint on the respiratory chain that does not affect its maximal activity. This kinetic constraint is offset by a decrease in the mitochondrial membrane potential, which induces a thermodynamic constraint on the ATPase responsible for a decrease in the ATP/ADP ratio.
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Affiliation(s)
- Guillaume Vial
- Université Grenoble AlpesGrenobleFrance
- Inserm U 1042GrenobleFrance
| | - Frédéric Lamarche
- Université Grenoble AlpesLBFAGrenobleFrance
- Inserm U 1055LBFAGrenobleFrance
| | | | | | - Anne‐Laure Borel
- Université Grenoble AlpesGrenobleFrance
- Inserm U 1042GrenobleFrance
| | - Eric Fontaine
- Université Grenoble AlpesLBFAGrenobleFrance
- Inserm U 1055LBFAGrenobleFrance
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Peralta S, Pinto M, Arguello T, Garcia S, Diaz F, Moraes CT. Metformin delays neurological symptom onset in a mouse model of neuronal complex I deficiency. JCI Insight 2020; 5:141183. [PMID: 33148885 PMCID: PMC7710273 DOI: 10.1172/jci.insight.141183] [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: 06/09/2020] [Accepted: 09/21/2020] [Indexed: 12/24/2022] Open
Abstract
Complex I (also known as NADH-ubiquinone oxidoreductase) deficiency is the most frequent mitochondrial disorder present in childhood. NADH-ubiquinone oxidoreductase iron-sulfur protein 3 (NDUFS3) is a catalytic subunit of the mitochondrial complex I; NDUFS3 is conserved from bacteria and essential for complex I function. Mutations affecting complex I, including in the Ndufs3 gene, cause fatal neurodegenerative diseases, such as Leigh syndrome. No treatment is available for these conditions. We developed and performed a detailed molecular characterization of a neuron-specific Ndufs3 conditional KO mouse model. We showed that deletion of Ndufs3 in forebrain neurons reduced complex I activity, altered brain energy metabolism, and increased locomotor activity with impaired motor coordination, balance, and stereotyped behavior. Metabolomics analyses showed an increase of glycolysis intermediates, suggesting an adaptive response to the complex I defect. Administration of metformin to these mice delayed the onset of the neurological symptoms but not of neuronal loss. This improvement was likely related to enhancement of glucose uptake and utilization, which are known effects of metformin in the brain. Despite reports that metformin inhibits complex I activity, our findings did not show worsening a complex I defect nor increases in lactic acid, suggesting that metformin should be further evaluated for use in patients with mitochondrial encephalopathies. Metformin delays onset of mitochondrial encephalopathy in a CNS model of mitochondrial oxidative phosphorylation defect.
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Affiliation(s)
| | | | | | | | | | - Carlos T Moraes
- Department of Neurology and.,Department of Cell Biology, Miller School of Medicine, University of Miami, Miami, Florida, USA
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10
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Sundelin E, Jensen JB, Jakobsen S, Gormsen LC, Jessen N. Metformin Biodistribution: A Key to Mechanisms of Action? J Clin Endocrinol Metab 2020; 105:5850036. [PMID: 32480406 DOI: 10.1210/clinem/dgaa332] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/26/2020] [Indexed: 02/08/2023]
Abstract
Metformin has undisputed glucose-lowering effects in diabetes and an impressive safety record. It has also shown promising effects beyond diabetes, and several hundred clinical trials involving metformin are currently planned or active. Metformin targets intracellular effectors, but exactly which remain to be established, and in an era of precision medicine, an incomplete understanding of mechanisms of action may limit the use of metformin. Distribution of metformin depends on specific organic cation transporter proteins that are organ- and species-specific. Therefore, target tissues of metformin can be identified by cellular uptake of the drug, and exploring the biodistribution of the drug in humans becomes an attractive strategy to assist the many investigations into the mechanisms of action of metformin performed in animals. In this review, we combine the emerging evidence from the use of 11C-labeled metformin in humans to discuss metformin action in liver, intestines, and kidney, which are the organs with the most avid uptake of the drug.
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Affiliation(s)
- Elias Sundelin
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jonas Brorson Jensen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Steen Jakobsen
- Department of Nuclear Medicine & PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Lars C Gormsen
- Department of Nuclear Medicine & PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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11
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Li WD, Zang CJ, Yin S, Shen W, Sun QY, Zhao M. Metformin protects against mouse oocyte apoptosis defects induced by arecoline. Cell Prolif 2020; 53:e12809. [PMID: 32557964 PMCID: PMC7377942 DOI: 10.1111/cpr.12809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVES Arecoline is the main bioactive substance extracted from Areca catechu L, which has cell, neural and genetic toxicity. The function of arecoline in reproductive system has not been well explored. MATERIALS AND METHODS To investigate the toxic effects of arecoline on oocyte development, immunofluorescence staining, qPCR, Western blotting, sperm binding assays and in vitro fertilization were performed to evaluate oocyte meiosis competence and embryo development. RESULTS Our data revealed that arecoline exposure disrupts actin filament dynamics, spindle assembly and kinetochore-microtubule attachment stability in mouse oocytes, leading to aneuploidy and oocyte meiosis arrest. In addition, arecoline treatment disturbs the distribution of mitochondria, reduces ATP production and increases the level of oxidative stress, which ultimately induces oocyte apoptosis. Supplementation with metformin, a medicine for type 2 diabetes in the clinic, partially alleviates these damages. CONCLUSIONS Metformin has a protective effect on arecoline-induced mouse oocytes apoptosis.
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Affiliation(s)
- Wei-Dong Li
- College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, China.,College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
| | - Chuan-Jie Zang
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
| | - Shen Yin
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
| | - Wei Shen
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
| | - Qing-Yuan Sun
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China.,State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Minghui Zhao
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
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12
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Foretz M, Guigas B, Viollet B. Understanding the glucoregulatory mechanisms of metformin in type 2 diabetes mellitus. Nat Rev Endocrinol 2019; 15:569-589. [PMID: 31439934 DOI: 10.1038/s41574-019-0242-2] [Citation(s) in RCA: 346] [Impact Index Per Article: 69.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/11/2019] [Indexed: 02/07/2023]
Abstract
Despite its position as the first-line drug for treatment of type 2 diabetes mellitus, the mechanisms underlying the plasma glucose level-lowering effects of metformin (1,1-dimethylbiguanide) still remain incompletely understood. Metformin is thought to exert its primary antidiabetic action through the suppression of hepatic glucose production. In addition, the discovery that metformin inhibits the mitochondrial respiratory chain complex 1 has placed energy metabolism and activation of AMP-activated protein kinase (AMPK) at the centre of its proposed mechanism of action. However, the role of AMPK has been challenged and might only account for indirect changes in hepatic insulin sensitivity. Various mechanisms involving alterations in cellular energy charge, AMP-mediated inhibition of adenylate cyclase or fructose-1,6-bisphosphatase 1 and modulation of the cellular redox state through direct inhibition of mitochondrial glycerol-3-phosphate dehydrogenase have been proposed for the acute inhibition of gluconeogenesis by metformin. Emerging evidence suggests that metformin could improve obesity-induced meta-inflammation via direct and indirect effects on tissue-resident immune cells in metabolic organs (that is, adipose tissue, the gastrointestinal tract and the liver). Furthermore, the gastrointestinal tract also has a major role in metformin action through modulation of glucose-lowering hormone glucagon-like peptide 1 and the intestinal bile acid pool and alterations in gut microbiota composition.
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Affiliation(s)
- Marc Foretz
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Bruno Guigas
- Department of Parasitology, Leiden University Medical Centre, Leiden, Netherlands
| | - Benoit Viollet
- INSERM, U1016, Institut Cochin, Paris, France.
- CNRS, UMR8104, Paris, France.
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
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13
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Manu KA, Cao PHA, Chai TF, Casey PJ, Wang M. p21cip1/waf1 Coordinate Autophagy, Proliferation and Apoptosis in Response to Metabolic Stress. Cancers (Basel) 2019; 11:cancers11081112. [PMID: 31382612 PMCID: PMC6721591 DOI: 10.3390/cancers11081112] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 12/12/2022] Open
Abstract
Cancer cells possess metabolic properties that are different from benign cells. These unique characteristics have become attractive targets that are being actively investigated for cancer therapy. p21cip1/waf1, also known as Cyclin-Dependent Kinase inhibitor 1A, is encoded by the CDKN1A gene. It is a major p53 target gene involved in cell cycle progression that has been extensively evaluated. To date, p21 has been reported to regulate various cell functions, both dependent and independent of p53. Besides regulating the cell cycle, p21 also modulates apoptosis, induces senescence, and maintains cellular quiescence in response to various stimuli. p21 transcription is induced in response to stresses, including those from oxidative and chemotherapeutic treatment. A recent study has shown that in response to metabolic stresses such as nutrient and energy depletion, p21 expression is induced to regulate various cell functions. Despite the biological significance, the mechanism of p21 regulation in cancer adaptation to metabolic stress is underexplored and thus represents an exciting field. This review focuses on the recent development of p21 regulation in response to metabolic stress and its impact in inducing cell cycle arrest and death in cancer cells.
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Affiliation(s)
- Kanjoormana Aryan Manu
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Pham Hong Anh Cao
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Tin Fan Chai
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Patrick J Casey
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mei Wang
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore.
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14
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Barbieri F, Verduci I, Carlini V, Zona G, Pagano A, Mazzanti M, Florio T. Repurposed Biguanide Drugs in Glioblastoma Exert Antiproliferative Effects via the Inhibition of Intracellular Chloride Channel 1 Activity. Front Oncol 2019; 9:135. [PMID: 30918838 PMCID: PMC6424887 DOI: 10.3389/fonc.2019.00135] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 02/14/2019] [Indexed: 12/12/2022] Open
Abstract
The lack of in-depth knowledge about the molecular determinants of glioblastoma (GBM) occurrence and progression, combined with few effective and BBB crossing-targeted compounds represents a major challenge for the discovery of novel and efficacious drugs for GBM. Among relevant molecular factors controlling the aggressive behavior of GBM, chloride intracellular channel 1 (CLIC1) represents an emerging prognostic and predictive biomarker, as well as a promising therapeutic target. CLIC1 is a metamorphic protein, co-existing as both soluble cytoplasmic and membrane-associated conformers, with the latter acting as chloride selective ion channel. CLIC1 is involved in several physiological cell functions and its abnormal expression triggers tumor development, favoring tumor cell proliferation, invasion, and metastasis. CLIC1 overexpression is associated with aggressive features of various human solid tumors, including GBM, in which its expression level is correlated with poor prognosis. Moreover, increasing evidence shows that modification of microglia ion channel activity, and CLIC1 in particular, contributes to the development of different neuropathological states and brain tumors. Intriguingly, CLIC1 is constitutively active within cancer stem cells (CSCs), while it seems less relevant for the survival of non-CSC GBM subpopulations and for normal cells. CSCs represent GBM development and progression driving force, being endowed with stem cell-like properties (self-renewal and differentiation), ability to survive therapies, to expand and differentiate, causing tumor recurrence. Downregulation of CLIC1 results in drastic inhibition of GBM CSC proliferation in vitro and in vivo, making the control of the activity this of channel a possible innovative pharmacological target. Recently, drugs belonging to the biguanide class (including metformin) were reported to selectively inhibit CLIC1 activity in CSCs, impairing their viability and invasiveness, but sparing normal stem cells, thus representing potential novel antitumor drugs with a safe toxicological profile. On these premises, we review the most recent insights into the biological role of CLIC1 as a potential selective pharmacological target in GBM. Moreover, we examine old and new drugs able to functionally target CLIC1 activity, discussing the challenges and potential development of CLIC1-targeted therapies.
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Affiliation(s)
- Federica Barbieri
- Sezione di Farmacologia, Dipartimento di Medicina Interna & Centro di Eccellenza per la Ricerca Biomedica, Università di Genoa, Genoa, Italy
| | - Ivan Verduci
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milan, Italy
| | - Valentina Carlini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milan, Italy
| | - Gianluigi Zona
- Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili, Università di Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Aldo Pagano
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy.,Dipartimento di Medicina Sperimentale, Università di Genoa, Genoa, Italy
| | - Michele Mazzanti
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milan, Italy
| | - Tullio Florio
- Sezione di Farmacologia, Dipartimento di Medicina Interna & Centro di Eccellenza per la Ricerca Biomedica, Università di Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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15
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Teh JT, Zhu WL, Newgard CB, Casey PJ, Wang M. Respiratory Capacity and Reserve Predict Cell Sensitivity to Mitochondria Inhibitors: Mechanism-Based Markers to Identify Metformin-Responsive Cancers. Mol Cancer Ther 2019; 18:693-705. [DOI: 10.1158/1535-7163.mct-18-0766] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/22/2018] [Accepted: 01/14/2019] [Indexed: 11/16/2022]
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16
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Vial G, Detaille D, Guigas B. Role of Mitochondria in the Mechanism(s) of Action of Metformin. Front Endocrinol (Lausanne) 2019; 10:294. [PMID: 31133988 PMCID: PMC6514102 DOI: 10.3389/fendo.2019.00294] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/24/2019] [Indexed: 12/15/2022] Open
Abstract
Metformin is a drug from the biguanide family that is used for decades as the first-line therapeutic choice for the treatment of type 2 diabetes. Despite its worldwide democratization, owing to its clinical efficacy, high safety profile and cheap cost, the exact mechanism(s) of action of this anti-hyperglycemic molecule with pleiotropic properties still remains to be fully elucidated. The concept that metformin would exert some of its actions though modulation of the mitochondrial bioenergetics was initially forged in the 50s but undeniably revived at the beginning of the twenty-first century when it was shown to induce a weak but specific inhibition of the mitochondrial respiratory-chain complex 1. Furthermore, metformin has been reported to reduce generation of reactive oxygen species at the complex 1 and to prevent mitochondrial-mediated apoptosis, suggesting that it can protect against oxidative stress-induced cell death. Nevertheless, despite some recent progress and the demonstration of its key role in the inhibition of hepatic gluconeogenesis, the exact nature of the mitochondrial interaction between the drug and the complex 1 is still poorly characterized. Recent studies reported that metformin may also have anti-neoplastic properties by inhibiting cancer cell growth and proliferation, at least partly through its mitochondrial action. As such, many trials are currently conducted for exploring the repositioning of metformin as a potential drug for cancer therapy. In this mini-review, we discuss both historical and more recent findings on the central role played by the interaction between metformin and the mitochondria in its cellular mechanism of action.
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Affiliation(s)
- Guillaume Vial
- Laboratoire Hypoxie-Physiopathologies Cardiovasculaires et Respiratoires HP2, Faculté de Médecine et de Pharmacie, INSERM U1042, La Tronche, France
- Laboratoire Hypoxie-Physiopathologies Cardiovasculaires et Respiratoires HP2, Faculté de Médecine et de Pharmacie, Université Grenoble-Alpes, La Tronche, France
| | - Dominique Detaille
- Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM U1045, Université de Bordeaux, Bordeaux, France
| | - Bruno Guigas
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
- *Correspondence: Bruno Guigas
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17
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Faure M, Bertoldo MJ, Khoueiry R, Bongrani A, Brion F, Giulivi C, Dupont J, Froment P. Metformin in Reproductive Biology. Front Endocrinol (Lausanne) 2018; 9:675. [PMID: 30524372 PMCID: PMC6262031 DOI: 10.3389/fendo.2018.00675] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 10/29/2018] [Indexed: 12/19/2022] Open
Abstract
Initially produced in Europe in 1958, metformin is still one of the most widely prescribed drugs to treat type II diabetes and other comorbidities associated with insulin resistance. Metformin has been shown to improve fertility outcomes in females with insulin resistance associated with polycystic ovary syndrome (PCOS) and in obese males with reduced fertility. Metformin treatment reinstates menstrual cyclicity, decreases the incidence of cesareans, and limits the number of premature births. Notably, metformin reduces steroid levels in conditions associated with hyperandrogenism (e.g., PCOS and precocious puberty) in females and improves fertility of adult men with metabolic syndrome through increased testosterone production. While the therapeutical use of metformin is considered to be safe, in the last 10 years some epidemiological studies have described phenotypic differences after prenatal exposure to metformin. The goals of this review are to briefly summarize the current knowledge on metformin focusing on its effects on the female and male reproductive organs, safety concerns, including the potential for modulating fetal imprinting via epigenetics.
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Affiliation(s)
- Melanie Faure
- Unité de Physiologie de la Reproduction et des Comportements, Centre Val de Loire, Institut National de la Recherche Agronomique, UMR85, Nouzilly, France
| | - Michael J Bertoldo
- Discipline of Obstetrics and Gynaecology, School of Women's and Children's Health, University of New South Wales, Sydney, NSW, Australia
| | - Rita Khoueiry
- Department of Development and Regeneration, Stem Cell Institute, KU Leuven, Leuven, Belgium
| | - Alice Bongrani
- Unité de Physiologie de la Reproduction et des Comportements, Centre Val de Loire, Institut National de la Recherche Agronomique, UMR85, Nouzilly, France
| | - François Brion
- INERIS, Direction des Risques Chroniques, Pole VIVA, Unite d'ecotoxicologie in vitro et in vivo, BP2, Verneuil-en-Halatte, France
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
- Medical Investigations of Neurodevelopmental Disorders Institute, University of California, Davis, Davis, CA, United States
| | - Joelle Dupont
- Unité de Physiologie de la Reproduction et des Comportements, Centre Val de Loire, Institut National de la Recherche Agronomique, UMR85, Nouzilly, France
| | - Pascal Froment
- Unité de Physiologie de la Reproduction et des Comportements, Centre Val de Loire, Institut National de la Recherche Agronomique, UMR85, Nouzilly, France
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18
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Metformin exerts antitumor activity via induction of multiple death pathways in tumor cells and activation of a protective immune response. Oncotarget 2018; 9:25808-25825. [PMID: 29899823 PMCID: PMC5995253 DOI: 10.18632/oncotarget.25380] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 04/24/2018] [Indexed: 12/22/2022] Open
Abstract
The antitumor effect of metformin has been demonstrated in several types of cancer; however, the mechanisms involved are incompletely understood. In this study, we showed that metformin acts directly on melanoma cells as well as on the tumor microenvironment, particularly in the context of the immune response. In vitro, metformin induces a complex interplay between apoptosis and autophagy in melanoma cells. The anti-metastatic activity of metformin in vivo was assessed in several mouse models challenged with B16F10 cells. Metformin's activity was, in part, immune system-dependent, whereas its antitumor properties were abrogated in immunodeficient (NSG) mice. Metformin treatment increased the number of lung CD8-effector-memory T and CD4+Foxp3+IL-10+ T cells in B16F10-transplanted mice. It also decreased the levels of Gr-1+CD11b+ and RORγ+ IL17+CD4+ cells in B16F10-injected mice and the anti-metastatic effect was impaired in RAG-1−/− mice challenged with B16F10 cells, suggesting an important role for T cells in the protection induced by metformin. Finally, metformin in combination with the clinical metabolic agents rapamycin and sitagliptin showed a higher antitumor effect. The metformin/sitagliptin combination was effective in a BRAFV600E/PTEN tamoxifen-inducible murine melanoma model. Taken together, these results suggest that metformin has a pronounced effect on melanoma cells, including the induction of a strong protective immune response in the tumor microenvironment, leading to tumor growth control, and the combination with other metabolic agents may increase this effect.
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19
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Fontaine E. Metformin-Induced Mitochondrial Complex I Inhibition: Facts, Uncertainties, and Consequences. Front Endocrinol (Lausanne) 2018; 9:753. [PMID: 30619086 PMCID: PMC6304344 DOI: 10.3389/fendo.2018.00753] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 11/27/2018] [Indexed: 12/24/2022] Open
Abstract
Metformin is the most widely prescribed drug to treat patients with type II diabetes, for whom retrospective studies suggest that metformin may have anticancer properties. However, in experiments performed with isolated cells, authors have reported both pro- and anti-apoptotic effects of metformin. The exact molecular mechanism of action of metformin remains partly unknown despite its use for over 60 years and more than 17,000 articles in PubMed. Among the various widely recognized or recently proposed targets, it has been reported consistently that metformin is capable of inhibiting mitochondrial respiratory chain Complex I. Since most of the effects of metformin have been replicated by other inhibitors of Complex I, it has been suggested that the mechanism of action of metformin involved the inhibition of Complex I. However, compared to conventional Complex I inhibitors, the metformin-induced inhibition of Complex I has unique characteristics. Among these, the most original one is that the concentrations of metformin required to inhibit Complex I are lower in intact cells than in isolated mitochondria. Experiments with isolated mitochondria or Complex I were generally performed using millimolar concentrations of metformin, while plasma levels remain in the micromolar range in both human and animal studies, highlighting that metformin concentration is an important issue. In order to explain the effects in animals based on observations in cells and mitochondria, some authors proposed a direct effect of the drug on Complex I involving an accumulation of metformin inside the mitochondria while others proposed an indirect effect (the drug no longer having to diffuse into the mitochondria). This brief review attempts to: gather arguments for and against each hypothesis concerning the mechanism by which metformin inhibits Complex I and to highlight remaining questions about the toxicity mechanism of metformin for certain cancer cells.
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20
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Abstract
The canonical Wnt/β-catenin signaling pathway, an important modulator of progenitor cell proliferation and differentiation, is highly regulated for the maintenance of critical biological homeostasis. Decades of studies in cancer genetics and genomics have demonstrated that multiple genes encoding key proteins in this signaling pathway serve as targets for recurrent mutational alterations. Among these proteins, β-catenin and adenomatosis polyposis coli (APC) are two key nodes. β-catenin contributes in transporting extracellular signals for nuclear programming. Mutations of the CTNNB1 gene that encodes β-catenin occur in a wide spectrum of cancers. These mutations alter the spatial characteristics of the β-catenin protein, leading to drastic reprogramming of the nuclear transcriptional network. Among the outcomes of this reprogramming are increased cell proliferation, enhanced immunosuppression, and disruption of metabolic regulation. Herein we review the current understanding of CTNNB1 mutations, their roles in tumorigenesis and discuss their possible therapeutic implications for cancer.
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21
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Lalau JD, Kajbaf F, Protti A, Christensen MM, De Broe ME, Wiernsperger N. Metformin-associated lactic acidosis (MALA): Moving towards a new paradigm. Diabetes Obes Metab 2017; 19:1502-1512. [PMID: 28417525 DOI: 10.1111/dom.12974] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/03/2017] [Accepted: 04/11/2017] [Indexed: 12/15/2022]
Abstract
Although metformin has been used for over 60 years, the balance between the drug's beneficial and adverse effects is still subject to debate. Following an analysis of how cases of so-called "metformin-associated lactic acidosis" (MALA) are reported in the literature, the present article reviews the pitfalls to be avoided when assessing the purported association between metformin and lactic acidosis. By starting from pathophysiological considerations, we propose a new paradigm for lactic acidosis in metformin-treated patients. Metformin therapy does not necessarily induce metformin accumulation, just as metformin accumulation does not necessarily induce hyperlactatemia, and hyperlactatemia does not necessarily induce lactic acidosis. In contrast to the conventional view, MALA probably accounts for a smaller proportion of cases than either metformin-unrelated lactic acidosis or metformin-induced lactic acidosis. Lastly, this review highlights the need for substantial improvements in the reporting of cases of lactic acidosis in metformin-treated patients. Accordingly, we propose a check-list as a guide to clinical practice.
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Affiliation(s)
- Jean-Daniel Lalau
- Department of Endocrinology-Nutrition, Amiens University Hospital, Amiens, France
| | - Farshad Kajbaf
- Department of Endocrinology-Nutrition, Amiens University Hospital, Amiens, France
| | - Alessandro Protti
- Department of Anesthesia and Intensive Care, IRCCS Fondazione Ca' Granda, Maggiore Policlinico Hospital, Milan, Italy
| | - Mette M Christensen
- Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, Odense, Denmark
| | - Marc E De Broe
- Laboratory of Pathophysiology, University of Antwerp, Wilrijk, Belgium
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22
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Shafiei-Irannejad V, Samadi N, Salehi R, Yousefi B, Zarghami N. New insights into antidiabetic drugs: Possible applications in cancer treatment. Chem Biol Drug Des 2017; 90:1056-1066. [DOI: 10.1111/cbdd.13013] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 03/27/2017] [Accepted: 04/23/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Vahid Shafiei-Irannejad
- Stem Cell Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Department of Clinical Biochemistry and Laboratory Medicine; Faculty of Medicine; Tabriz University of Medical Sciences; Tabriz Iran
| | - Nasser Samadi
- Department of Clinical Biochemistry and Laboratory Medicine; Faculty of Medicine; Tabriz University of Medical Sciences; Tabriz Iran
| | - Roya Salehi
- Department of Medical Nanotechnology; Faculty of Advanced Medical Sciences; Tabriz University of Medical Sciences; Tabriz Iran
| | - Bahman Yousefi
- Department of Clinical Biochemistry and Laboratory Medicine; Faculty of Medicine; Tabriz University of Medical Sciences; Tabriz Iran
| | - Nosratollah Zarghami
- Stem Cell Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Department of Clinical Biochemistry and Laboratory Medicine; Faculty of Medicine; Tabriz University of Medical Sciences; Tabriz Iran
- Department of Medical Biotechnology; Faculty of Advanced Medical Sciences; Tabriz University of Medical Sciences; Tabriz Iran
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23
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Niclosamide reduces glucagon sensitivity via hepatic PKA inhibition in obese mice: Implications for glucose metabolism improvements in type 2 diabetes. Sci Rep 2017; 7:40159. [PMID: 28054648 PMCID: PMC5214666 DOI: 10.1038/srep40159] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/02/2016] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes (T2D) is a global pandemic. Currently, the drugs used to treat T2D improve hyperglycemic symptom of the disease but the underlying mechanism causing the high blood glucose levels have not been fully resolved. Recently published data showed that salt form of niclosamide improved glucose metabolism in high fat fed mice via mitochondrial uncoupling. However, based on our previous work we hypothesised that niclosamide might also improve glucose metabolism via inhibition of the glucagon signalling in liver in vivo. In this study, mice were fed either a chow or high fat diet containing two different formulations of niclosamide (niclosamide ethanolamine salt - NENS or niclosamide - Nic) for 10 weeks. We identified both forms of niclosamide significantly improved whole body glucose metabolism without altering total body weight or body composition, energy expenditure or insulin secretion or sensitivity. Our study provides evidence that inhibition of the glucagon signalling pathway contributes to the beneficial effects of niclosamide (NENS or Nic) on whole body glucose metabolism. In conclusion, our results suggest that the niclosamide could be a useful adjunctive therapeutic strategy to treat T2D, as hepatic glucose output is elevated in people with T2D and current drugs do not redress this adequately.
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Mamputu JC, Wiernsperger N, Renier G. Metformin inhibits monocyte adhesion to endothelial cells and foam cell formation. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/14746514030030041501] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The United Kingdom Prospective Diabetes Study (UKPDS) found that metformin reduces macrovascular complications in type 2 diabetic patients. To investigate the mechanisms involved we examined the effect of metformin on monocyte adhesion to human endothelial cells (ECs) induced by advanced glycation end-products (AGE), and on monocyte differentiation into macrophages and foam cell formation. Treatment of human ECs with AGEs (100 µg/ml) for up to 12 hours significantly increased human monocyte adhesion. Pre-treatment of the cells with metformin (0.1—2.5 µg/ml) inhibited AGE-induced monocyte adhesion and expression of endothelial cell adhesion molecules. In culture, human monocytes spontaneously differentiated into macrophages, as indicated by phenotypic changes, and increased expression of lectin-like oxidised low-density lipoprotein (LDL) receptor and scavenger receptor type A. Incubation of these cells in the presence of metformin decreased expression of all of these parameters. Metformin also inhibited foam cell formation induced by minimally modified LDL. Overall, these results suggest new mechanisms by which metformin may reduce the risk of vascular complications in patients with type 2 diabetes.
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Affiliation(s)
- Jean-Claude Mamputu
- CHUM Research Centre, Notre-Dame Hospital, Department of Nutrition, University of Montreal, Montreal, Canada
| | | | - Geneviève Renier
- CHUM Research Centre, Notre-Dame Hospital, Department of Nutrition, University of Montreal, Montreal, Canada,
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25
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The Role of Metformin in Controlling Oxidative Stress in Muscle of Diabetic Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:6978625. [PMID: 27579154 PMCID: PMC4989083 DOI: 10.1155/2016/6978625] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 06/15/2016] [Accepted: 07/04/2016] [Indexed: 12/24/2022]
Abstract
Metformin can act in muscle, inhibiting the complex I of the electron transport chain and decreasing mitochondrial reactive oxygen species. Our hypothesis is that the inhibition of complex I can minimize damage oxidative in muscles of hypoinsulinemic rats. The present study investigated the effects of insulin and/or metformin treatment on oxidative stress levels in the gastrocnemius muscle of diabetic rats. Rats were rendered diabetic (D) with an injection of streptozotocin and were submitted to treatment with insulin (D+I), metformin (D+M), or insulin plus metformin (D+I+M) for 7 days. The body weight, glycemic control, and insulin resistance were evaluated. Then, oxidative stress levels, glutathione antioxidant defense system, and antioxidant status were analyzed in the gastrocnemius muscle of hypoinsulinemic rats. The body weight decreased in D+M compared to ND rats. D+I and D+I+M rats decreased the glycemia and D+I+M rats increased the insulin sensitivity compared to D rats. D+I+M reduced the oxidative stress levels and the activity of catalase and superoxide dismutase in skeletal muscle when compared to D+I rats. In conclusion, our results reveal that dual therapy with metformin and insulin promotes more benefits to oxidative stress control in muscle of hypoinsulinemic rats than insulinotherapy alone.
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Picone P, Vilasi S, Librizzi F, Contardi M, Nuzzo D, Caruana L, Baldassano S, Amato A, Mulè F, San Biagio PL, Giacomazza D, Di Carlo M. Biological and biophysics aspects of metformin-induced effects: cortex mitochondrial dysfunction and promotion of toxic amyloid pre-fibrillar aggregates. Aging (Albany NY) 2016; 8:1718-34. [PMID: 27509335 PMCID: PMC5032692 DOI: 10.18632/aging.101004] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 07/15/2016] [Indexed: 12/26/2022]
Abstract
The onset of Alzheimer disease (AD) is influenced by several risk factors comprising diabetes. Within this context, antidiabetic drugs, including metformin, are investigated for their effect on AD. We report that in the C57B6/J mice, metformin is delivered to the brain where activates AMP-activated kinase (AMPK), its molecular target. This drug affects the levels of β-secretase (BACE1) and β-amyloid precursor protein (APP), promoting processing and aggregation of β-amyloid (Aβ), mainly in the cortex region. Moreover, metformin induces mitochondrial dysfunction and cell death by affecting the level and conformation of Translocase of the Outer Membrane 40 (TOM40), voltage-dependent anion-selective channels 1 (VDAC1) and hexokinase I (HKI), proteins involved in mitochondrial transport of molecules, including Aβ. By using biophysical techniques we found that metformin is able to directly interact with Aβ influencing its aggregation kinetics and features. These findings indicate that metformin induces different adverse effects, leading to an overall increase of the risk of AD onset.
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Affiliation(s)
- Pasquale Picone
- Istituto di Biomedicina e Immunologia Molecolare, CNR, Palermo, Italy
| | | | | | - Marco Contardi
- Istituto di Biofisica, CNR, Palermo, Italy
- Current address: Italian Institute of Technology, Genova, Italy
| | - Domenico Nuzzo
- Istituto di Biomedicina e Immunologia Molecolare, CNR, Palermo, Italy
| | - Luca Caruana
- Istituto di Biomedicina e Immunologia Molecolare, CNR, Palermo, Italy
| | - Sara Baldassano
- Departimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, University of Palermo, Palermo, Italy
| | - Antonella Amato
- Departimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, University of Palermo, Palermo, Italy
| | - Flavia Mulè
- Departimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, University of Palermo, Palermo, Italy
| | | | | | - Marta Di Carlo
- Istituto di Biomedicina e Immunologia Molecolare, CNR, Palermo, Italy
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Wang H, Sharma L, Lu J, Finch P, Fletcher S, Prochownik EV. Structurally diverse c-Myc inhibitors share a common mechanism of action involving ATP depletion. Oncotarget 2016; 6:15857-70. [PMID: 26036281 PMCID: PMC4599242 DOI: 10.18632/oncotarget.4327] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 04/10/2015] [Indexed: 12/29/2022] Open
Abstract
The c-Myc (Myc) oncoprotein is deregulated in a large proportion of diverse human cancers. Considerable effort has therefore been directed at identifying pharmacologic inhibitors as potential anti-neoplastic agents. Three such groups of small molecule inhibitors have been described. The first is comprised of so-called “direct” inhibitors, which perturb Myc's ability to form productive DNA-binding heterodimers in association with its partner, Max. The second group is comprised of indirect inhibitors, which largely function by targeting the BET-domain protein BRD4 to prevent the proper formation of transcriptional complexes that assemble in response to Myc-Max DNA binding. Thirdly, synthetic lethal inhibitors cause the selective apoptosis of Myc over-expressing either by promoting mitotic catastrophe or altering Myc protein stability. We report here a common mechanism by which all Myc inhibitors, irrespective of class, lead to eventual cellular demise. This involves the depletion of ATP stores due to mitochondrial dysfunction and the eventual down-regulation of Myc protein. The accompanying metabolic de-regulation causes neutral lipid accumulation, cell cycle arrest, and an attempt to rectify the ATP deficit by up-regulating AMP-activated protein kinase (AMPK). These responses are ultimately futile due to the lack of functional Myc to support the requisite anabolic response. Finally, the effects of Myc depletion on ATP levels, cell cycle arrest, differentiation and AMPK activation can be mimicked by pharmacologic inhibition of the mitochondrial electron transport chain without affecting Myc levels. Thus, all Myc inhibitors promote a global energy collapse that appears to underlie many of their phenotypic consequences.
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Affiliation(s)
- Huabo Wang
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lokendra Sharma
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Jie Lu
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Paul Finch
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Steven Fletcher
- Department of Pharmaceutical Sciences, The University of Maryland School of Pharmacy, Baltimore, MD, USA.,The Greenebaum Cancer Center, Baltimore, MD, USA
| | - Edward V Prochownik
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Department of Microbiology and Molecular Genetics, The University of Pittsburgh, Pittsburgh, PA, USA.,The University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
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Imeglimin prevents human endothelial cell death by inhibiting mitochondrial permeability transition without inhibiting mitochondrial respiration. Cell Death Discov 2016; 2:15072. [PMID: 27551496 PMCID: PMC4979505 DOI: 10.1038/cddiscovery.2015.72] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 11/22/2015] [Indexed: 02/07/2023] Open
Abstract
Imeglimin is the first in a new class of oral glucose-lowering agents, having recently completed its phase 2b trial. As Imeglimin did show a full prevention of β-cell apoptosis, and since angiopathy represents a major complication of diabetes, we studied Imeglimin protective effects on hyperglycemia-induced death of human endothelial cells (HMEC-1). These cells were incubated in several oxidative stress environments (exposure to high glucose and oxidizing agent tert-butylhydroperoxide) which led to mitochondrial permeability transition pore (PTP) opening, cytochrome c release and cell death. These events were fully prevented by Imeglimin treatment. This protective effect on cell death occurred without any effect on oxygen consumption rate, on lactate production and on cytosolic redox or phosphate potentials. Imeglimin also dramatically decreased reactive oxygen species production, inhibiting specifically reverse electron transfer through complex I. We conclude that Imeglimin prevents hyperglycemia-induced cell death in HMEC-1 through inhibition of PTP opening without inhibiting mitochondrial respiration nor affecting cellular energy status. Considering the high prevalence of macrovascular and microvascular complications in type 2 diabetic subjects, these results together suggest a potential benefit of Imeglimin in diabetic angiopathy.
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Cai H, Zhang Y, Han TK, Everett RS, Thakker DR. Cation-selective transporters are critical to the AMPK-mediated antiproliferative effects of metformin in human breast cancer cells. Int J Cancer 2016; 138:2281-92. [DOI: 10.1002/ijc.29965] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 12/03/2015] [Indexed: 01/01/2023]
Affiliation(s)
- Hao Cai
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy; the University of North Carolina at Chapel Hill; Chapel Hill NC
| | - Yunhui Zhang
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy; the University of North Carolina at Chapel Hill; Chapel Hill NC
- Research Center for Drug Metabolism, Jilin University; Changchun People's Republic of China
| | - Tianxiang Kevin Han
- Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy; the University of North Carolina at Chapel Hill; Chapel Hill NC
| | - Ruth S. Everett
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy; the University of North Carolina at Chapel Hill; Chapel Hill NC
| | - Dhiren R. Thakker
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy; the University of North Carolina at Chapel Hill; Chapel Hill NC
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Cui H, Hense BA, Müller J, Schröder P. Short term uptake and transport process for metformin in roots of Phragmites australis and Typha latifolia. CHEMOSPHERE 2015; 134:307-312. [PMID: 25966936 DOI: 10.1016/j.chemosphere.2015.04.072] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 04/24/2015] [Accepted: 04/26/2015] [Indexed: 05/29/2023]
Abstract
Metformin (MET) as an emerging contaminant has been detected in surface water and wastewater in numerous countries, due to insufficient retention in classical waste water treatment plants. In order to characterize the uptake of the compound during phytotreatment of waste water, a short term Pitman chamber experiment was carried out to assess the characteristics of MET uptake and transport by roots. Three different concentrations (0.5, 1.0 and 2.0 mmol L(-)(1)) were applied to cattail (Typha latifolia) and reed (Phragmites australis) roots which were used to investigate the uptake mechanism because they are frequently utilized in phytoremediation. In addition, quinidine was used as an inhibitor to assess the role of organic cation transporters (OCTs) in the uptake of MET by T. latifolia. The transport process of MET is different from carbamazepine (CBZ) and caffeine (CFN). In both T. latifolia and P. australis, the uptake processes were independent of initial concentrations. Quinidine, a known inhibitor of organic cation transporters, can significantly affect MET uptake by T. latifolia roots with inhibition ratios of 70-74%. Uptake into the root could be characterized by a linear model with R(2) values in the range of 0.881-0.999. Overall, the present study provides evidence that MET is taken up by plant roots and has the potential for subsequent translocation. OCTs could be one of the important pathways for MET uptake into the plant.
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Affiliation(s)
- H Cui
- Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit Environmental Genomics, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - B A Hense
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute for Computational Biology, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - J Müller
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute for Computational Biology, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; Technical University of Munich, Centre for Mathematical Sciences Unit M12, Botzmannstr. 3, 85747 Garching, Germany
| | - P Schröder
- Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit Environmental Genomics, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany.
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Differential associations of circulating asymmetric dimethylarginine and cell adhesion molecules with metformin use in patients with type 2 diabetes mellitus and stable coronary artery disease. Amino Acids 2015; 47:1951-9. [DOI: 10.1007/s00726-015-1976-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/30/2015] [Indexed: 10/23/2022]
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Picone P, Nuzzo D, Caruana L, Messina E, Barera A, Vasto S, Di Carlo M. Metformin increases APP expression and processing via oxidative stress, mitochondrial dysfunction and NF-κB activation: Use of insulin to attenuate metformin's effect. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1046-59. [PMID: 25667085 DOI: 10.1016/j.bbamcr.2015.01.017] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 01/21/2015] [Accepted: 01/25/2015] [Indexed: 12/14/2022]
Abstract
Clinical and experimental biomedical studies have shown Type 2 diabetes mellitus (T2DM) to be a risk factor for the development of Alzheimer's disease (AD). This study demonstrates the effect of metformin, a therapeutic biguanide administered for T2DM therapy, on β-amyloid precursor protein (APP) metabolism in in vitro, ex vivo and in vivo models. Furthermore, the protective role of insulin against metformin is also demonstrated. In LAN5 neuroblastoma cells, metformin increases APP and presenilin levels, proteins involved in AD. Overexpression of APP and presenilin 1 (Pres 1) increases APP cleavage and intracellular accumulation of β-amyloid peptide (Aβ), which, in turn, promotes aggregation of Aβ. In the experimental conditions utilized the drug causes oxidative stress, mitochondrial damage, decrease of Hexokinase-II levels and cytochrome C release, all of which lead to cell death. Several changes in oxidative stress-related genes following metformin treatment were detected by PCR arrays specific for the oxidative stress pathway. These effects of metformin were found to be antagonized by the addition of insulin, which reduced Aβ levels, oxidative stress, mitochondrial dysfunction and cell death. Similarly, antioxidant molecules, such as ferulic acid and curcumin, are able to revert metformin's effect. Comparable results were obtained using peripheral blood mononuclear cells. Finally, the involvement of NF-κB transcription factor in regulating APP and Pres 1 expression was investigated. Upon metformin treatment, NF-κB is activated and translocates from the cytoplasm to the nucleus, where it induces increased APP and Pres 1 transcription. The use of Bay11-7085 inhibitor suppressed the effect of metformin on APP and Pres 1 expression.
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Affiliation(s)
- Pasquale Picone
- Institute of Biomedicine and Molecular Immunology "Alberto Monroy" (IBIM), Consiglio Nazionale delle Ricerche (CNR), 90146 Palermo, Italy
| | - Domenico Nuzzo
- Institute of Biomedicine and Molecular Immunology "Alberto Monroy" (IBIM), Consiglio Nazionale delle Ricerche (CNR), 90146 Palermo, Italy
| | - Luca Caruana
- Institute of Biomedicine and Molecular Immunology "Alberto Monroy" (IBIM), Consiglio Nazionale delle Ricerche (CNR), 90146 Palermo, Italy
| | - Elisa Messina
- Institute of Biomedicine and Molecular Immunology "Alberto Monroy" (IBIM), Consiglio Nazionale delle Ricerche (CNR), 90146 Palermo, Italy
| | - Annalisa Barera
- Department of STEBICEF, University of Palermo, 90100 Palermo, Italy
| | - Sonya Vasto
- Institute of Biomedicine and Molecular Immunology "Alberto Monroy" (IBIM), Consiglio Nazionale delle Ricerche (CNR), 90146 Palermo, Italy; Department of STEBICEF, University of Palermo, 90100 Palermo, Italy
| | - Marta Di Carlo
- Institute of Biomedicine and Molecular Immunology "Alberto Monroy" (IBIM), Consiglio Nazionale delle Ricerche (CNR), 90146 Palermo, Italy.
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Abstract
Metformin is the most widely prescribed drug used to treat patients affected by Type 2 diabetes. Metformin has also been shown to prevent some forms of cell death; however, evidence suggests that it may have anti-neoplastic properties. All of these effects have been attributed to complex I inhibition, but the mechanism by which metformin leads to complex I inhibition is not fully understood. Although it has been reported that the incubation of functionally isolated complex I in the presence of high concentrations of metformin led to its inhibition, much lower concentrations of metformin have been shown to inhibit complex I in intact cells. In a recent issue of the Biochemical Journal, Bridges, Jones, Pollak and Hirst [(2014) Biochem. J. 462, 475-487] studied for the first time the effect of metformin on purified complex I. They report that millimolar concentrations of metformin directly inhibit complex I activity in a non-competitive manner. They also specify that the binding of metformin to complex I depends on its conformation. To explain the difference in concentration required to inhibit complex I in intact cells and on isolated enzyme, Bridges et al. (2014) propose that metformin concentrates within mitochondria in intact cells. Albeit theoretically plausible, this attractive hypothesis is not directly tested by Bridges et al. (2014) Moreover, although sparse, the current literature does not support this hypothesis.
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Tsai CM, Kuo HC, Hsu CN, Huang LT, Tain YL. Metformin reduces asymmetric dimethylarginine and prevents hypertension in spontaneously hypertensive rats. Transl Res 2014; 164:452-9. [PMID: 25168015 DOI: 10.1016/j.trsl.2014.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 07/15/2014] [Accepted: 07/16/2014] [Indexed: 10/24/2022]
Abstract
Elevated asymmetric dimethylarginine (ADMA) levels and nitric oxide (NO) deficiency are associated with the development of hypertension. Metformin, an antidiabetic agent, is a structural analog of ADMA. We examined whether metformin can prevent the development of hypertension in spontaneously hypertensive rats (SHRs) by restoration of ADMA-NO balance. SHRs and control normotensive Wistar-Kyoto (WKY) rats were assigned to 4 groups (N = 8 for each group): untreated SHRs and WKY rats, metformin-treated SHRs and WKY rats. Metformin-treated rats received metformin 500 mg/kg per day via oral gavage for 8 weeks. All rats were sacrificed at the age of 12 weeks. We found an increase in the blood pressure of SHRs was prevented by metformin. ADMA levels in the plasma and lung were elevated in SHRs, which metformin prevented. Lung dimethylarginine dimethylaminohydrolase (DDAH, ADMA-metabolizing enzyme) activity was lower in SHRs than WKY rats. Next, metformin had no effect on protein arginine methyltransferase 1 (ADMA-synthesizing enzyme), DDAH-1, DDAH-2, NO synthase enzymes, and DDAH activity in the kidney. Moreover, metformin increased the levels of NO in kidney. Conclusively, the observed antihypertensive effect of metformin in SHRs is because of the restoration of the ADMA-NO pathway. Our findings support the consideration of metformin as an antihypertensive agent for diabetic patients with prehypertension.
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Affiliation(s)
- Chih-Min Tsai
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University, College of Medicine, Taoyuan, Taiwan
| | - Hsuan-Chang Kuo
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University, College of Medicine, Taoyuan, Taiwan
| | - Chien-Ning Hsu
- Department of Pharmacy, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; School of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Li-Tung Huang
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University, College of Medicine, Taoyuan, Taiwan
| | - You-Lin Tain
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Chang Gung University, College of Medicine, Taoyuan, Taiwan; Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
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Ali I, Hussain I, Sanagi MM, Ibrahim WAW, Aboul-Enein HY. Analyses of Biguanides and Related Compounds in Biological and Environmental Samples by HPLC. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2014.940803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Imran Ali
- a Department of Chemistry , Jamia Millia Islamia (Central University) , New Delhi , India
| | - Iqbal Hussain
- b Department of Chemistry, Faculty of Science , Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
- c Ibnu Sina Institute for Fundamental Science Studies, Nanotechnology Reseach Alliance , Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
| | - Mohd Marsin Sanagi
- b Department of Chemistry, Faculty of Science , Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
- c Ibnu Sina Institute for Fundamental Science Studies, Nanotechnology Reseach Alliance , Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
| | - Wan Aini Wan Ibrahim
- b Department of Chemistry, Faculty of Science , Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
- c Ibnu Sina Institute for Fundamental Science Studies, Nanotechnology Reseach Alliance , Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
| | - Hassan Y. Aboul-Enein
- d Department of Pharmaceutical and Medicinal Chemistry , Pharmaceutical and Drug Industries Research Division, National Research Centre , Dokki , Cairo , Egypt
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Bertoldo MJ, Faure M, Dupont J, Froment P. Impact of metformin on reproductive tissues: an overview from gametogenesis to gestation. ANNALS OF TRANSLATIONAL MEDICINE 2014; 2:55. [PMID: 25333030 DOI: 10.3978/j.issn.2305-5839.2014.06.04] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 05/21/2014] [Indexed: 12/29/2022]
Abstract
Metformin is an oral anti-hyperglycemic drug that acts as an insulin sensitizer in the treatment of diabetes mellitus type 2. It has also been widely used in the treatment of polycystic ovary syndrome (PCOS) and gestational diabetes. This drug has been shown to activate a protein kinase called 5' AMP-activated protein kinase or AMPK. AMPK is present in many tissues making metformin's effect multi factorial. However as metformin crosses the placenta, its use during pregnancy raises concerns regarding potential adverse effects on the mother and fetus. The majority of reports suggest no significant adverse effects or teratogenicity. However, disconcerting reports of male mouse offspring that were exposed to metformin in utero that present with a reduction in testis size, seminiferous tubule size and in Sertoli cell number suggest that we do not understand the full suite of effects of metformin. In addition, recent molecular evidence is suggesting an epigenetic effect of metformin which could explain some of the long-term effects reported. Nevertheless, the data are still insufficient to completely confirm or disprove negative effects of metformin. The aims of this review are to provide a summary of the safety of metformin in various aspects of sexual reproduction, the use of metformin by gestating mothers, and its possible side-effects on offspring from women who are administered metformin during pregnancy.
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Affiliation(s)
- Michael J Bertoldo
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, Centre Val de Loire, UMR85, 37380 Nouzilly, France
| | - Melanie Faure
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, Centre Val de Loire, UMR85, 37380 Nouzilly, France
| | - Joelle Dupont
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, Centre Val de Loire, UMR85, 37380 Nouzilly, France
| | - Pascal Froment
- Unité de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, Centre Val de Loire, UMR85, 37380 Nouzilly, France
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Wessels B, Ciapaite J, van den Broek NMA, Nicolay K, Prompers JJ. Metformin impairs mitochondrial function in skeletal muscle of both lean and diabetic rats in a dose-dependent manner. PLoS One 2014; 9:e100525. [PMID: 24950069 PMCID: PMC4065055 DOI: 10.1371/journal.pone.0100525] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/28/2014] [Indexed: 12/02/2022] Open
Abstract
Metformin is a widely prescribed drug for the treatment of type 2 diabetes. Previous studies have demonstrated in vitro that metformin specifically inhibits Complex I of the mitochondrial respiratory chain. This seems contraindicative since muscle mitochondrial dysfunction has been linked to the pathogenesis of type 2 diabetes. However, its significance for in vivo skeletal muscle mitochondrial function has yet to be elucidated. The aim of this study was to assess the effects of metformin on in vivo and ex vivo skeletal muscle mitochondrial function in a rat model of diabetes. Healthy (fa/+) and diabetic (fa/fa) Zucker diabetic fatty rats were treated by oral gavage with metformin dissolved in water (30, 100 or 300 mg/kg bodyweight/day) or water as a control for 2 weeks. After 2 weeks of treatment, muscle oxidative capacity was assessed in vivo using 31P magnetic resonance spectroscopy and ex vivo by measuring oxygen consumption in isolated mitochondria using high-resolution respirometry. Two weeks of treatment with metformin impaired in vivo muscle oxidative capacity in a dose-dependent manner, both in healthy and diabetic rats. Whereas a dosage of 30 mg/kg/day had no significant effect, in vivo oxidative capacity was 21% and 48% lower after metformin treatment at 100 and 300 mg/kg/day, respectively, independent of genotype. High-resolution respirometry measurements demonstrated a similar dose-dependent effect of metformin on ex vivo mitochondrial function. In conclusion, metformin compromises in vivo and ex vivo muscle oxidative capacity in Zucker diabetic fatty rats in a dose-dependent manner.
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Affiliation(s)
- Bart Wessels
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Jolita Ciapaite
- Department of Pediatrics, Centre for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Nicole M. A. van den Broek
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Jeanine J. Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- * E-mail:
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Abstract
Metformin has been the mainstay of therapy for diabetes mellitus for many years; however, the mechanistic aspects of metformin action remained ill-defined. Recent advances revealed that this drug, in addition to its glucose-lowering action, might be promising for specifically targeting metabolic differences between normal and abnormal metabolic signalling. The knowledge gained from dissecting the principal mechanisms by which metformin works can help us to develop novel treatments. The centre of metformin's mechanism of action is the alteration of the energy metabolism of the cell. Metformin exerts its prevailing, glucose-lowering effect by inhibiting hepatic gluconeogenesis and opposing the action of glucagon. The inhibition of mitochondrial complex I results in defective cAMP and protein kinase A signalling in response to glucagon. Stimulation of 5'-AMP-activated protein kinase, although dispensable for the glucose-lowering effect of metformin, confers insulin sensitivity, mainly by modulating lipid metabolism. Metformin might influence tumourigenesis, both indirectly, through the systemic reduction of insulin levels, and directly, via the induction of energetic stress; however, these effects require further investigation. Here, we discuss the updated understanding of the antigluconeogenic action of metformin in the liver and the implications of the discoveries of metformin targets for the treatment of diabetes mellitus and cancer.
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Affiliation(s)
- Ida Pernicova
- Department of Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1A 6BQ, UK
| | - Márta Korbonits
- Department of Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1A 6BQ, UK
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Effect of metformin on the fertilizing ability of mouse spermatozoa. Cryobiology 2014; 68:262-8. [PMID: 24556364 DOI: 10.1016/j.cryobiol.2014.02.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 02/07/2014] [Accepted: 02/07/2014] [Indexed: 01/11/2023]
Abstract
Numerous antioxidants have been added to cryopreservation media with varied success. The biguanide, metformin, commonly used for the treatment of type II diabetes, possesses properties impacting metabolism control that have not been yet assessed in cryopreservation protocols. The aim of this experiment was to; (i) determine the effect of metformin on fresh spermatozoa properties; and (ii) to assess positive or negative effects of metformin in post-thaw function and fertilizing capacity of mouse spermatozoa when used in cryopreservation media. The experiments have shown that the presence of metformin in fresh semen did not induce negative effects on spermatozoa quality, except a slight reduction in sperm motility at 5000μM metformin. However, when metformin was included in a cryopreservation protocol, an improvement in the fertilization rate and a reduction in the percentage of abnormal zygotes after in vitro fertilization was observed. In conclusion, metformin did not affect sperm quality at low concentrations (50μM), but its presence in the cryopreservation media could represent a benefit to improve the quality of frozen semen.
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New molecules and old drugs as emerging approaches to selectively target human glioblastoma cancer stem cells. BIOMED RESEARCH INTERNATIONAL 2014; 2014:126586. [PMID: 24527434 PMCID: PMC3909978 DOI: 10.1155/2014/126586] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 12/04/2013] [Indexed: 02/07/2023]
Abstract
Despite relevant progress obtained by multimodal treatment, glioblastoma (GBM), the most aggressive primary brain tumor, is still incurable. The most encouraging advancement of GBM drug research derives from the identification of cancer stem cells (CSCs), since these cells appear to represent the determinants of resistance to current standard therapies. The goal of most ongoing studies is to identify drugs able to affect CSCs biology, either inducing selective toxicity or differentiating this tumor cell population into nontumorigenic cells. Moreover, the therapeutic approach for GBM could be improved interfering with chemo- or radioresistance mechanisms, microenvironment signals, and the neoangiogenic process. During the last years, molecular targeted compounds such as sorafenib and old drugs, like metformin, displayed interesting efficacy in preclinical studies towards several tumors, including GBM, preferentially affecting CSC viability. In this review, the latest experimental results, controversies, and prospective application concerning these promising anticancer drugs will be discussed.
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Viollet B, Foretz M. Revisiting the mechanisms of metformin action in the liver. ANNALES D'ENDOCRINOLOGIE 2013; 74:123-9. [PMID: 23582849 DOI: 10.1016/j.ando.2013.03.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Although considerable efforts have been made since the 1950s to better understand the action of metformin, the first line therapeutic for type 2 diabetes, its mechanisms of action has not been fully elucidated. The main antidiabetic effect of this drug is to decrease hepatic glucose production. A plausible molecular mechanism of action now emerges from recent breakthroughs that place metformin at the control of energy homeostasis. Metformin was shown to induce a mild and transient inhibition of the mitochondrial respiratory chain complex 1. The resulting decrease in hepatic energy state activates the AMP-activated protein kinase (AMPK), a cellular metabolic sensor, and provided a generally accepted mechanism for metformin action on hepatic gluconeogenic program. However, the role of AMPK activation in metformin action has recently been challenged by loss-of-function experiments. Recent evidence showed that metformin-induced inhibition of hepatic glucose output is mediated by reducing cellular energy charge rather than direct inhibition of gluconeogenic gene expression. Furthermore, recent data support a novel mechanism of action for metformin involving antagonism of glucagon signaling pathways by inducing the accumulation of AMP, which inhibits adenylate cyclase and reduced levels of cAMP.
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Affiliation(s)
- Benoit Viollet
- Département endocrinologie, métabolisme et cancer, Inserm, U1016, Institut Cochin, 24, rue du Faubourg-Saint-Jacques, 75014 Paris, France.
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Fu A, Eberhard CE, Screaton RA. Role of AMPK in pancreatic beta cell function. Mol Cell Endocrinol 2013; 366:127-34. [PMID: 22766107 DOI: 10.1016/j.mce.2012.06.020] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 05/08/2012] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
Abstract
Pharmacological activation of AMP activated kinase (AMPK) by metformin has proven to be a beneficial therapeutic approach for the treatment of type II diabetes. Despite improved glucose regulation achieved by administration of small molecule activators of AMPK, the potential negative impact of enhanced AMPK activity on insulin secretion by the pancreatic beta cell is an important consideration. In this review, we discuss our current understanding of the role of AMPK in central functions of the pancreatic beta cell, including glucose-stimulated insulin secretion (GSIS), proliferation, and survival. In addition we discuss the controversy surrounding the role of AMPK in insulin secretion, underscoring the merits and caveats of methods used to date.
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Affiliation(s)
- Accalia Fu
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada
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Buler M, Aatsinki SM, Izzi V, Hakkola J. Metformin reduces hepatic expression of SIRT3, the mitochondrial deacetylase controlling energy metabolism. PLoS One 2012; 7:e49863. [PMID: 23166782 PMCID: PMC3500349 DOI: 10.1371/journal.pone.0049863] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 10/18/2012] [Indexed: 02/07/2023] Open
Abstract
Metformin inhibits ATP production in mitochondria and this may be involved in the anti-hyperglycemic effects of the drug. Sirtuin 3 (SIRT3) is a mitochondrial protein deacetylase that regulates the function of the electron transport chain and maintains basal ATP yield. We hypothesized that metformin treatment could diminish mitochondrial ATP production through downregulation of SIRT3 expression. Glucagon and cAMP induced SIRT3 mRNA in mouse primary hepatocytes. Metformin prevented SIRT3 induction by glucagon. Moreover, metformin downregulated constitutive expression of SIRT3 in primary hepatocytes and in the liver in vivo. Estrogen related receptor alpha (ERRα) mediates regulation of Sirt3 gene by peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). ERRα mRNA expression was regulated in a similar manner as SIRT3 mRNA by glucagon, cAMP and metformin. However, a higher metformin concentration was required for downregulation of ERRα than SIRT3. ERRα siRNA attenuated PGC-1α mediated induction of SIRT3, but did not affect constitutive expression. Overexpression of the constitutively active form of AMP-activated protein kinase (AMPK) induced SIRT3 mRNA, indicating that the SIRT3 downregulation by metformin is not mediated by AMPK. Metformin reduced the hepatocyte ATP level. This effect was partially counteracted by SIRT3 overexpression. Furthermore, metformin decreased mitochondrial SIRT3 protein levels and this was associated with enhanced acetylation of several mitochondrial proteins. However, metformin increased mitochondrial mass in hepatocytes. Altogether, our results indicate that metformin attenuates mitochondrial expression of SIRT3 and suggest that this mechanism is involved in regulation of energy metabolism by metformin in the liver and may contribute to the therapeutic action of metformin.
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Affiliation(s)
- Marcin Buler
- Department of Pharmacology and Toxicology, Institute of Biomedicine, University of Oulu, Oulu, Finland
| | - Sanna-Mari Aatsinki
- Department of Pharmacology and Toxicology, Institute of Biomedicine, University of Oulu, Oulu, Finland
| | - Valerio Izzi
- Center for Cell-Matrix Research and Biocenter Oulu, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - Jukka Hakkola
- Department of Pharmacology and Toxicology, Institute of Biomedicine, University of Oulu, Oulu, Finland
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Protti A, Lecchi A, Fortunato F, Artoni A, Greppi N, Vecchio S, Fagiolari G, Moggio M, Comi GP, Mistraletti G, Lanticina B, Faraldi L, Gattinoni L. Metformin overdose causes platelet mitochondrial dysfunction in humans. Crit Care 2012; 16:R180. [PMID: 23034133 PMCID: PMC3682281 DOI: 10.1186/cc11663] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/10/2012] [Accepted: 08/31/2012] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION We have recently demonstrated that metformin intoxication causes mitochondrial dysfunction in several porcine tissues, including platelets. The aim of the present work was to clarify whether it also causes mitochondrial dysfunction (and secondary lactate overproduction) in human platelets, in vitro and ex vivo. METHODS Human platelets were incubated for 72 hours with saline or increasing doses of metformin (in vitro experiments). Lactate production, respiratory chain complex activities (spectrophotometry), mitochondrial membrane potential (flow-cytometry after staining with JC-1) and oxygen consumption (Clark-type electrode) were then measured. Platelets were also obtained from ten patients with lactic acidosis (arterial pH 6.97 ± 0.18 and lactate 16 ± 7 mmol/L) due to accidental metformin intoxication (serum drug level 32 ± 14 mg/L) and ten healthy volunteers of similar sex and age. Respiratory chain complex activities were measured as above (ex vivo experiments). RESULTS In vitro, metformin dose-dependently increased lactate production (P < 0.001), decreased respiratory chain complex I activity (P = 0.009), mitochondrial membrane potential (P = 0.003) and oxygen consumption (P < 0.001) of human platelets. Ex vivo, platelets taken from intoxicated patients had significantly lower complex I (P = 0.045) and complex IV (P < 0.001) activity compared to controls. CONCLUSIONS Depending on dose, metformin can cause mitochondrial dysfunction and lactate overproduction in human platelets in vitro and, possibly, in vivo. TRIAL REGISTRATION NCT 00942123.
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Affiliation(s)
- Alessandro Protti
- Dipartimento di Anestesia, Rianimazione (Intensiva e Sub-Intensiva) e Terapia del Dolore, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, via F. Sforza 35, 20122 Milan, Italy
| | - Anna Lecchi
- Centro Emofilia e Trombosi Angelo Bianchi Bonomi, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, via F. Sforza 35, 20122 Milan, Italy
| | - Francesco Fortunato
- Centro Dino Ferrari - Dipartimento di Scienze Neurologiche, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, via F. Sforza 35, 20122 Milan, Italy
| | - Andrea Artoni
- Centro Emofilia e Trombosi Angelo Bianchi Bonomi, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, via F. Sforza 35, 20122 Milan, Italy
| | - Noemi Greppi
- Centro Trasfusionale e di Immunoematologia, Dipartimento di Medicina Rigenerativa, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, via F. Sforza 35, 20122 Milan, Italy
| | - Sarah Vecchio
- Centro Nazionale di Informazione Tossicologica - Centro Antiveleni, Fondazione IRCCS Salvatore Maugeri, via S. Maugeri 10/10A, 27100 Pavia, Italy
| | - Gigliola Fagiolari
- Centro Dino Ferrari - Dipartimento di Scienze Neurologiche, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, via F. Sforza 35, 20122 Milan, Italy
| | - Maurizio Moggio
- Centro Dino Ferrari - Dipartimento di Scienze Neurologiche, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, via F. Sforza 35, 20122 Milan, Italy
| | - Giacomo Pietro Comi
- Centro Dino Ferrari - Dipartimento di Scienze Neurologiche, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, via F. Sforza 35, 20122 Milan, Italy
| | - Giovanni Mistraletti
- U.O. Anestesia e Rianimazione, A.O. San Paolo, Università degli Studi di Milano, via A. Di Rudiní 8, 20142 Milan, Italy
| | - Barbara Lanticina
- U.O. Rianimazione, A.O. San Carlo Borromeo, via Pio II 3, 20147 Milan, Italy
| | - Loredana Faraldi
- Servizio Anestesia e Rianimazione 1°, Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore 3, 20162 Milan, Italy
| | - Luciano Gattinoni
- Dipartimento di Anestesia, Rianimazione (Intensiva e Sub-Intensiva) e Terapia del Dolore, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, via F. Sforza 35, 20122 Milan, Italy
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Mitochondrial stress causes increased succination of proteins in adipocytes in response to glucotoxicity. Biochem J 2012; 445:247-54. [PMID: 22524437 DOI: 10.1042/bj20112142] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
2SC [S-(2-succino)-cysteine] is a chemical modification formed by a Michael addition reaction of fumarate with cysteine residues in proteins. Formation of 2SC, termed 'succination' of proteins, increases in adipocytes grown in high-glucose medium and in adipose tissues of Type 2 diabetic mice. However, the metabolic mechanisms leading to increased fumarate and succination of protein in the adipocyte are unknown. Treatment of 3T3 cells with high glucose (30 mM compared with 5 mM) caused a significant increase in cellular ATP/ADP, NADH/NAD+ and Δψm (mitochondrial membrane potential). There was also a significant increase in the cellular fumarate concentration and succination of proteins, which may be attributed to the increase in NADH/NAD+ and subsequent inhibition of tricarboxylic acid cycle NAD+-dependent dehydrogenases. Chemical uncouplers, which dissipated Δψm and reduced the NADH/NAD+ ratio, also decreased the fumarate concentration and protein succination. High glucose plus metformin, an inhibitor of complex I in the electron transport chain, caused an increase in fumarate and succination of protein. Thus excess fuel supply (glucotoxicity) appears to create a pseudohypoxic environment (high NADH/NAD+ without hypoxia), which drives the increase in succination of protein. We propose that increased succination of proteins is an early marker of glucotoxicity and mitochondrial stress in adipose tissue in diabetes.
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Targeting metabolism for cancer treatment and prevention: metformin, an old drug with multi-faceted effects. Oncogene 2012; 32:1475-87. [PMID: 22665053 DOI: 10.1038/onc.2012.181] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding the complexity of cancer and of the underlying regulatory networks provides a new paradigm that tackles cancer development and treatment through a system biology approach, contemporarily acting on various intersecting pathways. Cancer cell metabolism is an old pathogenetic issue that has recently gained new interest as target for therapeutic approaches. More than 70 years ago, Warburg discovered that malignant cells generally have altered metabolism with high rates of glucose uptake and increased glycolysis, even under aerobic condition. Observational studies have provided evidence that impaired metabolism, obesity, hyperglycemia and hyperinsulinemia may have a role in cancer development, progression and prognosis, and actually diabetic and obese patients have increased cancer risk. On the other hand, caloric restriction has been shown to prolong life span and reduce cancer incidence in several animal models, having an impact on different metabolic pathways. Metformin, an antidiabetic drug widely used for over 40 years, mimics caloric restriction acting on cell metabolism at multiple levels, reducing all energy-consuming processes in the cells, including cell proliferation. By overviewing molecular mechanisms of action, epidemiological evidences, experimental data in tumor models and early clinical study results, this review provides information supporting the promising use of metformin in cancer prevention and treatment.
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Lamming DW, Sabatini DM, Baur JA. Pharmacologic Means of Extending Lifespan. JOURNAL OF CLINICAL & EXPERIMENTAL PATHOLOGY 2012; Suppl 4:7327. [PMID: 25379357 PMCID: PMC4219537 DOI: 10.4172/2161-0681.s4-002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Dudley W. Lamming
- Department of Biology, MIT, Cambridge, MA 02139, Howard
Hughes Medical Institute, MIT, Cambridge, MA 02139; Whitehead Institute for
Biomedical Research, Cambridge MA 02142, Broad Institute of Harvard and MIT, Seven
Cambridge Center, Cambridge, MA 02142, The David H. Koch Institute for Integrative
Cancer Research at MIT, Cambridge, MA 02139, USA
| | - David M. Sabatini
- Department of Biology, MIT, Cambridge, MA 02139, Howard
Hughes Medical Institute, MIT, Cambridge, MA 02139; Whitehead Institute for
Biomedical Research, Cambridge MA 02142, Broad Institute of Harvard and MIT, Seven
Cambridge Center, Cambridge, MA 02142, The David H. Koch Institute for Integrative
Cancer Research at MIT, Cambridge, MA 02139, USA
| | - Joseph A. Baur
- Department of Physiology, Institute for Diabetes, Obesity,
and Metabolism, Perelman School of Medicine, University of Pennsylvania,
Philadelphia PA 19104, USA
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Langelueddecke C, Jakab M, Ketterl N, Lehner L, Hufnagl C, Schmidt S, Geibel JP, Fuerst J, Ritter M. Effect of the AMP-kinase modulators AICAR, metformin and compound C on insulin secretion of INS-1E rat insulinoma cells under standard cell culture conditions. Cell Physiol Biochem 2012; 29:75-86. [PMID: 22415077 DOI: 10.1159/000337589] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The function of β-cells is regulated by nutrient uptake and metabolism. The cells' metabolic state can be expressed as concentration ratios of AMP, ADP and ATP. Relative changes in these ratios regulate insulin release. An increase in the intracellular ATP concentration causes closure of K(ATP) channels and cell membrane depolarization, which triggers stimulus-secretion coupling (SSC). In addition to K(ATP) channels, the AMP-dependent protein kinase (AMPK), a major cellular fuel sensor in a variety of cells and tissues, also affects insulin secretion and β-cell survival. In a previous study we found that the widely used AMPK inhibitor compound C retards proliferation and induces apoptosis in the rat β-cell line INS-1E. We therefore tested the effects of AMPK activators (AICAR and metformin), and compound C on AMPK phosphorylation, insulin secretion, K(ATP) channel currents, cell membrane potential, intracellular calcium concentration, apoptosis and cell cycle distribution of INS-1E cells under standard cell culture conditions (11 mM glucose). METHODS Western blotting, ELISA, patch-clamp, calcium imaging and flow cytometry. RESULTS We found that basal AMPK phosphorylation is enhanced by AICAR (1 mM) and metformin (1 mM) but remained unaffected by compound C (10 μM). Both AICAR and compound C stimulated basal insulin secretion whereas metformin had no effect. Pre-incubation with AICAR (1 mM) caused an inhibition of K(ATP) currents but did not significantly alter the average cell membrane potential (Vm) or the threshold potential of electrical activity. Acute administration of AICAR (300 μM) led to a depolarization of Vm, which was not due to an inhibition of the basal- or glucose-induced chloride conductance, and was not accompanied by elevations of intracellular calcium (Ca(i)). AICAR had no additive blocking effect on K(ATP) currents when applied together with tolbutamide. Compound C applied over 24 hours induced an increase in the percentage of cells positive for caspase activity, whereas AICAR (1 mM) applied for 48 hours was without effect. Medium glucose concentration <3 mM caused cell cycle arrest, caspase activation and an increase of cell granularity. CONCLUSION We conclude that under standard cell culture conditions the AMPK modulators AICAR and compound C, but not metformin, stimulate insulin secretion by AMPK-independent mechanisms.
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Abstract
Considerable efforts have been made since the 1950s to better understand the cellular and molecular mechanisms of action of metformin, a potent antihyperglycaemic agent now recommended as the first-line oral therapy for T2D (Type 2 diabetes). The main effect of this drug from the biguanide family is to acutely decrease hepatic glucose production, mostly through a mild and transient inhibition of the mitochondrial respiratory chain complex I. In addition, the resulting decrease in hepatic energy status activates AMPK (AMP-activated protein kinase), a cellular metabolic sensor, providing a generally accepted mechanism for the action of metformin on hepatic gluconeogenesis. The demonstration that respiratory chain complex I, but not AMPK, is the primary target of metformin was recently strengthened by showing that the metabolic effect of the drug is preserved in liver-specific AMPK-deficient mice. Beyond its effect on glucose metabolism, metformin has been reported to restore ovarian function in PCOS (polycystic ovary syndrome), reduce fatty liver, and to lower microvascular and macrovascular complications associated with T2D. Its use has also recently been suggested as an adjuvant treatment for cancer or gestational diabetes and for the prevention in pre-diabetic populations. These emerging new therapeutic areas for metformin will be reviewed together with recent findings from pharmacogenetic studies linking genetic variations to drug response, a promising new step towards personalized medicine in the treatment of T2D.
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Stephenne X, Foretz M, Taleux N, van der Zon GC, Sokal E, Hue L, Viollet B, Guigas B. Metformin activates AMP-activated protein kinase in primary human hepatocytes by decreasing cellular energy status. Diabetologia 2011; 54:3101-10. [PMID: 21947382 PMCID: PMC3210354 DOI: 10.1007/s00125-011-2311-5] [Citation(s) in RCA: 199] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Accepted: 08/18/2011] [Indexed: 01/27/2023]
Abstract
AIM/HYPOTHESIS The glucose-lowering drug metformin has been shown to activate hepatic AMP-activated protein kinase (AMPK), a master kinase regulating cellular energy homeostasis. However, the underlying mechanisms remain controversial and have never been investigated in primary human hepatocytes. METHODS Hepatocytes isolated from rat, mouse and human livers were treated with various concentrations of metformin. Isoform-specific AMPKα abundance and activity, as well as intracellular adenine nucleotide levels and mitochondrial oxygen consumption rates were determined at different time points. RESULTS Metformin dose- and time-dependently increased AMPK activity in rat and human hepatocytes, an effect associated with a significant rise in cellular AMP:ATP ratio. Surprisingly, we found that AMPKα2 activity was undetectable in human compared with rat hepatocytes, while AMPKα1 activities were comparable. Accordingly, metformin only increased AMPKα1 activity in human hepatocytes, although both AMPKα isoforms were activated in rat hepatocytes. Analysis of mRNA expression and protein levels confirmed that only AMPKα1 is present in human hepatocytes; it also showed that the distribution of β and γ regulatory subunits differed between species. Finally, we demonstrated that the increase in AMP:ATP ratio in hepatocytes from liver-specific Ampkα1/2 (also known as Prkaa1/2) knockout mice and humans is due to a similar and specific inhibition of the mitochondrial respiratory-chain complex 1 by metformin. CONCLUSIONS/INTERPRETATION Activation of hepatic AMPK by metformin results from a decrease in cellular energy status owing to metformin's AMPK-independent inhibition of the mitochondrial respiratory-chain complex 1. The unique profile of AMPK subunits found in human hepatocytes should be considered when developing new pharmacological agents to target the kinase.
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Affiliation(s)
- X. Stephenne
- Laboratory of Paediatric Hepatology and Cell Therapy, Université catholique de Louvain and Cliniques St Luc, Brussels, Belgium
| | - M. Foretz
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Paris, France
| | - N. Taleux
- Hormone and Metabolic Research Unit, Université catholique de Louvain and de Duve Institute, Brussels, Belgium
- Bioénergétique Fondamentale et Appliquée Inserm-U884, Université J. Fourier, Grenoble, France
| | - G. C. van der Zon
- Department of Molecular Cell Biology, Leiden University Medical Center, Postzone S1-P, Postbus 9600, 2300 RC Leiden, the Netherlands
| | - E. Sokal
- Laboratory of Paediatric Hepatology and Cell Therapy, Université catholique de Louvain and Cliniques St Luc, Brussels, Belgium
| | - L. Hue
- Hormone and Metabolic Research Unit, Université catholique de Louvain and de Duve Institute, Brussels, Belgium
| | - B. Viollet
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Paris, France
| | - B. Guigas
- Hormone and Metabolic Research Unit, Université catholique de Louvain and de Duve Institute, Brussels, Belgium
- Department of Molecular Cell Biology, Leiden University Medical Center, Postzone S1-P, Postbus 9600, 2300 RC Leiden, the Netherlands
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