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Abstract
Animal behavior was classically considered to be determined exclusively by neuronal activity, whereas surrounding glial cells such as astrocytes played only supportive roles. However, astrocytes are as numerous as neurons in the mammalian brain, and current findings indicate a chemically based dialog between astrocytes and neurons. Activation of astrocytes by synaptically released neurotransmitters converges on regulating intracellular Ca2+ in astrocytes, which then can regulate the efficacy of near and distant tripartite synapses at diverse timescales through gliotransmitter release. Here, we discuss recent evidence on how diverse behaviors are impacted by this dialog. These recent findings support a paradigm shift in neuroscience, in which animal behavior does not result exclusively from neuronal activity but from the coordinated activity of both astrocytes and neurons. Decoding how astrocytes and neurons interact with each other in various brain circuits will be fundamental to fully understanding how behaviors originate and become dysregulated in disease.
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Affiliation(s)
- Paulo Kofuji
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA;
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA;
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102
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Belsham DD, Dalvi PS. Insulin signalling in hypothalamic neurones. J Neuroendocrinol 2020; 33:e12919. [PMID: 33227171 DOI: 10.1111/jne.12919] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 12/15/2022]
Abstract
Subsequent to the discovery of insulin by Banting and Best in the Department of Physiology at the University of Toronto 100 years ago, the field of insulin signalling and action has grown at a remarkable pace. Yet, the recognition that insulin action in the brain is critical for whole body homeostasis has only recently been appreciated. The hypothalamus is a key region in the brain that responds to circulating insulin by engaging a complex signalling cascade resulting in the ultimate release of neuropeptides that control hunger and feeding. Disruption of this important feedback system can lead to a phenomenon called cellular insulin resistance, where the neurones cease to sense insulin. The factors contributing to insulin resistance, as well as the resulting detrimental effects, include the induction of neuroinflammation, endoplasmic reticulum stress and alterations in the architecture of the blood-brain barrier that allow transport of insulin into the brain. These manifestations usually change energy balance, causing weight gain, often resulting in obesity and its deadly comorbidities, including type 2 diabetes mellitus, cardiovascular disease and metabolic syndrome. Nonetheless, there is still hope because the signal transduction pathways can be targeted at a number of levels by neurone-specific therapeutics. With the advent of unique cell models for investigating the mechanisms involved in these processes, the discovery of novel targets is increasingly possible. Although we are still looking for a cure for diabetes, Banting and Best would be impressed at how far their discovery has advanced and the contemporary knowledge that has been accumulated based on insulin action.
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Affiliation(s)
- Denise D Belsham
- Departments of Physiology, Obstetrics and Gynaecology and Medicine, University of Toronto, Toronto, ON, Canada
| | - Prasad S Dalvi
- Biology Department, Morosky College of Health Professions and Sciences, Gannon University, Erie, PA, USA
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103
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Robb JL, Morrissey NA, Weightman Potter PG, Smithers HE, Beall C, Ellacott KLJ. Immunometabolic Changes in Glia - A Potential Role in the Pathophysiology of Obesity and Diabetes. Neuroscience 2020; 447:167-181. [PMID: 31765625 PMCID: PMC7567742 DOI: 10.1016/j.neuroscience.2019.10.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 12/15/2022]
Abstract
Chronic low-grade inflammation is a feature of the pathophysiology of obesity and diabetes in the CNS as well as peripheral tissues. Glial cells are critical mediators of the response to inflammation in the brain. Key features of glia include their metabolic flexibility, sensitivity to changes in the CNS microenvironment, and ability to rapidly adapt their function accordingly. They are specialised cells which cooperate to promote and preserve neuronal health, playing important roles in regulating the activity of neuronal networks across the brain during different life stages. Increasing evidence points to a role of glia, most notably astrocytes and microglia, in the systemic regulation of energy and glucose homeostasis in the course of normal physiological control and during disease. Inflammation is an energetically expensive process that requires adaptive changes in cellular metabolism and, in turn, metabolic intermediates can also have immunomodulatory actions. Such "immunometabolic" changes in peripheral immune cells have been implicated in contributing to disease pathology in obesity and diabetes. This review will discuss the evidence for a role of immunometabolic changes in glial cells in the systemic regulation of energy and glucose homeostasis, and how this changes in the context of obesity and diabetes.
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Affiliation(s)
- Josephine L Robb
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Nicole A Morrissey
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Paul G Weightman Potter
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Hannah E Smithers
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Craig Beall
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Kate L J Ellacott
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK.
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104
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Bomba M, Granzotto A, Castelli V, Onofrj M, Lattanzio R, Cimini A, Sensi SL. Exenatide Reverts the High-Fat-Diet-Induced Impairment of BDNF Signaling and Inflammatory Response in an Animal Model of Alzheimer's Disease. J Alzheimers Dis 2020; 70:793-810. [PMID: 31256135 DOI: 10.3233/jad-190237] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is a multifactorial condition in which, along with amyloid-β (Aβ) and tau-related pathology, the synergistic activity of co-morbidity factors promote the onset and progression of the disease. Epidemiological evidence indicates that glucose intolerance, deficits in insulin secretion, or type-2 diabetes mellitus (T2DM) participate in increasing cognitive impairment or dementia risk. Insulin plays a pivotal role in the process as the hormone critically regulates brain functioning. GLP-1, the glucagon-like peptide 1, facilitates insulin signaling, regulates glucose homeostasis, and modulates synaptic plasticity. Exenatide is a synthetic GLP-1 analog employed in T2DM. However, exenatide has also been shown to affect the signaling of the brain-derived neurotrophic factor (BDNF), synaptic plasticity, and cognitive performances in animal models. In this study, we tested whether exenatide exerts neuroprotection in a preclinical AD model set to mimic the clinical complexity of the human disease. We investigated the effects of exenatide treatment in 3xTg-AD mice challenged with a high-fat diet (HFD). Endpoints of the study were variations in systemic metabolism, insulin and neurotrophic signaling, neuroinflammation, Aβ and tau pathology, and cognitive performances. Results of the study indicate that exenatide reverts the adverse changes of BDNF signaling and the neuroinflammation status of 3xTg-AD mice undergoing HFD without affecting systemic metabolism or promoting changes in cognitive performances.
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Affiliation(s)
- Manuela Bomba
- Center of Excellence on Aging and Translational Medicine - CeSI-MeT, University G. d'Annunzio of Chieti-Pescara, Italy.,Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Italy
| | - Alberto Granzotto
- Center of Excellence on Aging and Translational Medicine - CeSI-MeT, University G. d'Annunzio of Chieti-Pescara, Italy.,Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Italy
| | - Vanessa Castelli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy
| | - Marco Onofrj
- Center of Excellence on Aging and Translational Medicine - CeSI-MeT, University G. d'Annunzio of Chieti-Pescara, Italy.,Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Italy
| | - Rossano Lattanzio
- Center of Excellence on Aging and Translational Medicine - CeSI-MeT, University G. d'Annunzio of Chieti-Pescara, Italy.,Department of Medical, Oral, and Biotechnological Sciences, University G. d'Annunzio of Chieti-Pescara, Italy
| | - Annamaria Cimini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Italy.,Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, PA, USA.,National Institute for Nuclear Physics (INFN), Gran Sasso National Laboratory (LNGS), Assergi, Italy
| | - Stefano L Sensi
- Center of Excellence on Aging and Translational Medicine - CeSI-MeT, University G. d'Annunzio of Chieti-Pescara, Italy.,Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Italy.,Departments of Neurology and Pharmacology, Institute for Mind Impairments and Neurological Disorders - iMIND, University of California - Irvine, Irvine, CA, USA
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105
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Frazier HN, Anderson KL, Ghoweri AO, Lin RL, Hawkinson TR, Popa GJ, Sompol P, Mendenhall MD, Norris CM, Thibault O. Molecular elevation of insulin receptor signaling improves memory recall in aged Fischer 344 rats. Aging Cell 2020; 19:e13220. [PMID: 32852134 PMCID: PMC7576226 DOI: 10.1111/acel.13220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/16/2020] [Accepted: 07/22/2020] [Indexed: 12/24/2022] Open
Abstract
As demonstrated by increased hippocampal insulin receptor density following learning in animal models and decreased insulin signaling, receptor density, and memory decline in aging and Alzheimer's diseases, numerous studies have emphasized the importance of insulin in learning and memory processes. This has been further supported by work showing that intranasal delivery of insulin can enhance insulin receptor signaling, alter cerebral blood flow, and improve memory recall. Additionally, inhibition of insulin receptor function or expression using molecular techniques has been associated with reduced learning. Here, we sought a different approach to increase insulin receptor activity without the need for administering the ligand. A constitutively active, modified human insulin receptor (IRβ) was delivered to the hippocampus of young (2 months) and aged (18 months) male Fischer 344 rats in vivo. The impact of increasing hippocampal insulin receptor expression was investigated using several outcome measures, including Morris water maze and ambulatory gait performance, immunofluorescence, immunohistochemistry, and Western immunoblotting. In aged animals, the IRβ construct was associated with enhanced performance on the Morris water maze task, suggesting that this receptor was able to improve memory recall. Additionally, in both age-groups, a reduced stride length was noted in IRβ-treated animals along with elevated hippocampal insulin receptor levels. These results provide new insights into the potential impact of increasing neuronal insulin signaling in the hippocampus of aged animals and support the efficacy of molecularly elevating insulin receptor activity in vivo in the absence of the ligand to directly study this process.
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Affiliation(s)
| | - Katie L. Anderson
- Department of Pharmacology and Nutritional SciencesLexingtonKentuckyUSA
| | - Adam O. Ghoweri
- Department of Pharmacology and Nutritional SciencesLexingtonKentuckyUSA
| | - Ruei-Lung Lin
- Department of Pharmacology and Nutritional SciencesLexingtonKentuckyUSA
| | - Tara R. Hawkinson
- Department of Pharmacology and Nutritional SciencesLexingtonKentuckyUSA
| | - Gabriel J. Popa
- Department of Molecular and Cellular BiochemistryLexingtonKentuckyUSA
| | - Pradoldej Sompol
- Sanders-Brown Center on AgingUniversity of KentuckyLexingtonKentuckyUSA
| | | | | | - Olivier Thibault
- Department of Pharmacology and Nutritional SciencesLexingtonKentuckyUSA
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106
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Manaserh IH, Maly E, Jahromi M, Chikkamenahalli L, Park J, Hill J. Insulin sensing by astrocytes is critical for normal thermogenesis and body temperature regulation. J Endocrinol 2020; 247:39-52. [PMID: 32698146 PMCID: PMC7456332 DOI: 10.1530/joe-20-0052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 12/23/2022]
Abstract
The important role of astrocytes in the central control of energy balance and glucose homeostasis has recently been recognized. Changes in thermoregulation can lead to metabolic dysregulation, but the role of astrocytes in this process is not yet clear. Therefore, we generated mice congenitally lacking insulin receptors (Ir) in astrocytes (IrKOGFAP mice) to investigate the involvement of astrocyte insulin signaling. IrKOGFAP mice displayed significantly lower energy expenditure and a strikingly lower basal and fasting body temperature. When exposed to cold, however, they were able to mount a thermogenic response. IrKOGFAP mice displayed sex differences in metabolic function and thermogenesis that may contribute to the development of obesity and type II diabetes as early as 2 months of age. While brown adipose tissue exhibited higher adipocyte size in both sexes, more apoptosis was seen in IrKOGFAP males. Less innervation and lower BAR3 expression levels were also observed in IrKOGFAP brown adipose tissue. These effects have not been reported in models of astrocyte Ir deletion in adulthood. In contrast, body weight and glucose regulatory defects phenocopied such models. These findings identify a novel role for astrocyte insulin signaling in the development of normal body temperature control and sympathetic activation of BAT. Targeting insulin signaling in astrocytes has the potential to serve as a novel target for increasing energy expenditure.
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Affiliation(s)
- Iyad H Manaserh
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Emily Maly
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Marziyeh Jahromi
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Lakshmikanth Chikkamenahalli
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Joshua Park
- Department of Neuroscience, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Jennifer Hill
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
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107
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Clinical Evidence of Antidepressant Effects of Insulin and Anti-Hyperglycemic Agents and Implications for the Pathophysiology of Depression-A Literature Review. Int J Mol Sci 2020; 21:ijms21186969. [PMID: 32971941 PMCID: PMC7554794 DOI: 10.3390/ijms21186969] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/21/2020] [Accepted: 09/15/2020] [Indexed: 02/07/2023] Open
Abstract
Close connections between depression and type 2 diabetes (T2DM) have been suggested by many epidemiological and experimental studies. Disturbances in insulin sensitivity due to the disruption of various molecular pathways cause insulin resistance, which underpins many metabolic disorders, including diabetes, as well as depression. Several anti-hyperglycemic agents have demonstrated antidepressant properties in clinical trials, probably due to their action on brain targets based on the shared pathophysiology of depression and T2DM. In this article, we review reports of clinical trials examining the antidepressant effect of these medications, including insulin, metformin, glucagon like peptide-1 receptor agonists (GLP-1RA), and peroxisome proliferator-activated receptor (PPAR)-γ agonists, and briefly consider possible molecular mechanisms underlying the associations between amelioration of insulin resistance and improvement of depressive symptoms. In doing so, we intend to suggest an integrative perspective for understanding the pathophysiology of depression.
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108
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Heni M, Eckstein SS, Schittenhelm J, Böhm A, Hogrefe N, Irmler M, Beckers J, Hrabě de Angelis M, Häring HU, Fritsche A, Staiger H. Ectopic fat accumulation in human astrocytes impairs insulin action. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200701. [PMID: 33047031 PMCID: PMC7540778 DOI: 10.1098/rsos.200701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/12/2020] [Indexed: 05/13/2023]
Abstract
Astrocytes provide neurons with structural support and energy in form of lactate, modulate synaptic transmission, are insulin sensitive and act as gatekeeper for water, ions, glutamate and second messengers. Furthermore, astrocytes are important for glucose sensing, possess neuroendocrine functions and also play an important role in cerebral lipid metabolism. To answer the question, if there is a connection between lipid metabolism and insulin action in human astrocytes, we investigated if storage of ectopic lipids in human astrocytes has an impact on insulin signalling in those cells. Human astrocytes were cultured in the presence of a lipid emulsion, consisting of fatty acids and triglycerides, to induce ectopic lipid storage. After several days, cells were stimulated with insulin and gene expression profiling was performed. In addition, phosphorylation of Akt as well as glycogen synthesis and cell proliferation was assessed. Ectopic lipid storage was detected in human astrocytes after lipid exposure and lipid storage was persistent even when the fat emulsion was removed from the cell culture medium. Chronic exposure to lipids induced profound changes in the gene expression profile, whereby some genes showed a reversible gene expression profile upon removal of fat, and some did not. This included FOXO-dependent expression patterns. Furthermore, insulin-induced phosphorylation of Akt was diminished and also insulin-induced glycogen synthesis and proliferation was impaired in lipid-laden astrocytes. Chronic lipid exposure induces lipid storage in human astrocytes accompanied by insulin resistance. Analyses of the gene expression pattern indicated the potential of a partially reversible gene expression profile. Targeting astrocytic insulin resistance by reducing ectopic lipid load might represent a promising treatment target for insulin resistance of the brain in obesity, diabetes and neurodegeneration.
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Affiliation(s)
- Martin Heni
- Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Department for Diagnostic Laboratory Medicine, Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
- Author for correspondence: Martin Heni e-mail:
| | - Sabine S. Eckstein
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Jens Schittenhelm
- Division of Neuropathology, University Hospital Tübingen, Tübingen, Germany
| | - Anja Böhm
- Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Norbert Hogrefe
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Johannes Beckers
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Chair for Experimental Genetics, Technische Universität München, Freising, Germany
| | - Martin Hrabě de Angelis
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Chair for Experimental Genetics, Technische Universität München, Freising, Germany
| | - Hans-Ulrich Häring
- Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Andreas Fritsche
- Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Harald Staiger
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute of Pharmaceutical Sciences, Department of Pharmacy and Biochemistry, Eberhard Karls University Tübingen, Tübingen, Germany
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109
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Kullmann S, Kleinridders A, Small DM, Fritsche A, Häring HU, Preissl H, Heni M. Central nervous pathways of insulin action in the control of metabolism and food intake. Lancet Diabetes Endocrinol 2020; 8:524-534. [PMID: 32445739 DOI: 10.1016/s2213-8587(20)30113-3] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/22/2020] [Accepted: 03/20/2020] [Indexed: 12/18/2022]
Abstract
Insulin acts on the CNS to modulate behaviour and systemic metabolism. Disturbances in brain insulin action represent a possible link between metabolic and cognitive health. Current findings from human research suggest that boosting central insulin action in the brain modulates peripheral metabolism, enhancing whole-body insulin sensitivity and suppressing endogenous glucose production. Moreover, central insulin action curbs food intake by reducing the salience of highly palatable food cues and increasing cognitive control. Animal models show that the mesocorticolimbic circuitry is finely tuned in response to insulin, driven mainly by the dopamine system. These mechanisms are impaired in people with obesity, which might increase their risk of developing type 2 diabetes and associated diseases. Overall, current findings highlight the role of insulin action in the brain and its consequences on peripheral metabolism and cognition. Hence, improving central insulin action could represent a therapeutic option for people at an increased risk of developing metabolic and cognitive diseases.
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Affiliation(s)
- Stephanie Kullmann
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Neuherberg, Germany.
| | - André Kleinridders
- German Center for Diabetes Research, Neuherberg, Germany; Central Regulation of Metabolism, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Dana M Small
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Psychiatry, Yale University, New Haven, CT, USA; Modern Diet and Physiology Research Centre, Yale University, New Haven, CT, USA
| | - Andreas Fritsche
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Neuherberg, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Neuherberg, Germany
| | - Hubert Preissl
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Pharmacy and Biochemistry, Interfaculty Centre for Pharmacogenomics and Pharma Research, Eberhard Karls University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Martin Heni
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, and Nephrology, Eberhard Karls University of Tübingen, Tübingen, Germany; German Center for Diabetes Research, Neuherberg, Germany
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110
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Cai Y, Guo H, Fan Z, Zhang X, Wu D, Tang W, Gu T, Wang S, Yin A, Tao L, Ji X, Dong H, Li Y, Xiong L. Glycogenolysis Is Crucial for Astrocytic Glycogen Accumulation and Brain Damage after Reperfusion in Ischemic Stroke. iScience 2020; 23:101136. [PMID: 32446205 PMCID: PMC7240195 DOI: 10.1016/j.isci.2020.101136] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/27/2020] [Accepted: 04/30/2020] [Indexed: 12/23/2022] Open
Abstract
Astrocytic glycogen is an important energy reserve in the brain and is believed to supply fuel during energy crisis. However, the pattern of glycogen metabolism in ischemic stroke and its potential therapeutic impact on neurological outcomes are still unknown. Here, we found extensive brain glycogen accumulation after reperfusion in ischemic stroke patients and primates. Glycogenolytic dysfunction in astrocytes is responsible for glycogen accumulation, caused by inactivation of the protein kinase A (PKA)-glycogen phosphorylase kinase (PhK)-glycogen phosphorylase (GP) cascade accompanied by the activation of glycogen synthase kinase-3β (GSK3β). Genetic or pharmacological augmentation of astrocytic GP could promote astrocyte and neuron survival and improve neurological behaviors. In addition, we found that insulin exerted a neuroprotective effect, at least in part by rescuing the PKA-PhK-GP cascade to maintain homeostasis of glycogen metabolism during reperfusion. Together, our findings suggest a promising intervention for undesirable outcomes in ischemic stroke.
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Affiliation(s)
- Yanhui Cai
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Haiyun Guo
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Ze Fan
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Xinlei Zhang
- Department of Medicinal Chemistry, School of Pharmacy, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Di Wu
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Wenhong Tang
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Tingting Gu
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Shiquan Wang
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Anqi Yin
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Liang Tao
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Xunming Ji
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Hailong Dong
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Yan Li
- Center for Brain Science & Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Lize Xiong
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
- Translational Research Institute of Brain and Brain-Like Intelligence & Department of Anesthesiology and Perioperative Medicine, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai 200081, China
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111
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Mansur RB, Lee Y, McIntyre RS, Brietzke E. What is bipolar disorder? A disease model of dysregulated energy expenditure. Neurosci Biobehav Rev 2020; 113:529-545. [PMID: 32305381 DOI: 10.1016/j.neubiorev.2020.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/30/2020] [Accepted: 04/05/2020] [Indexed: 12/24/2022]
Abstract
Advances in the understanding and management of bipolar disorder (BD) have been slow to emerge. Despite notable recent developments in neurosciences, our conceptualization of the nature of this mental disorder has not meaningfully progressed. One of the key reasons for this scenario is the continuing lack of a comprehensive disease model. Within the increasing complexity of modern research methods, there is a clear need for an overarching theoretical framework, in which findings are assimilated and predictions are generated. In this review and hypothesis article, we propose such a framework, one in which dysregulated energy expenditure is a primary, sufficient cause for BD. Our proposed model is centered on the disruption of the molecular and cellular network regulating energy production and expenditure, as well its potential secondary adaptations and compensatory mechanisms. We also focus on the putative longitudinal progression of this pathological process, considering its most likely periods for onset, such as critical periods that challenges energy homeostasis (e.g. neurodevelopment, social isolation), and the resulting short and long-term phenotypical manifestations.
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Affiliation(s)
- Rodrigo B Mansur
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
| | - Yena Lee
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Elisa Brietzke
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Kingston General Hospital, Providence Care Hospital, Department of Psychiatry, Queen's University School of Medicine, Kingston, ON, Canada
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112
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Kleinridders A, Pothos EN. Impact of Brain Insulin Signaling on Dopamine Function, Food Intake, Reward, and Emotional Behavior. Curr Nutr Rep 2020; 8:83-91. [PMID: 31001792 DOI: 10.1007/s13668-019-0276-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Dietary obesity is primarily attributed to an imbalance between food intake and energy expenditure. Adherence to lifestyle interventions reducing weight is typically low. As a result, obesity becomes a chronic state with increased co-morbidities such as insulin resistance and diabetes. We review the effects of brain insulin action and dopaminergic signal transmission on food intake, reward, and mood as well as potential modulations of these systems to counteract the obesity epidemic. RECENT FINDINGS Central insulin and dopamine action are interlinked and impact on food intake, reward, and mood. Brain insulin resistance causes hyperphagia, anxiety, and depressive-like behavior and compromises the dopaminergic system. Such effects can induce reduced compliance to medical treatment. Insulin receptor sensitization and dopamine receptor agonists show attenuation of obesity and improvement of mental health in rodents and humans. Modulating brain insulin and dopamine signaling in obese patients can potentially improve therapeutic outcomes.
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Affiliation(s)
- André Kleinridders
- Central Regulation of Metabolism, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558, Nuthetal, Germany. .,German Center for Diabetes Research (DZD), Ingolstaedter Land Str. 1, 85764, Neuherberg, Germany.
| | - Emmanuel N Pothos
- Program in Pharmacology and Experimental Therapeutics and Pharmacology and Drug Development, Sackler School of Graduate Biomedical Sciences and Department of Immunology, Tufts University School of Medicine, Boston, MA, 02111, USA.
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113
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Kulas JA, Weigel TK, Ferris HA. Insulin resistance and impaired lipid metabolism as a potential link between diabetes and Alzheimer's disease. Drug Dev Res 2020; 81:194-205. [PMID: 32022298 DOI: 10.1002/ddr.21643] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/20/2019] [Accepted: 01/23/2020] [Indexed: 12/13/2022]
Abstract
Diabetes disrupts organs throughout the body including the brain. Evidence suggests diabetes is a risk factor for Alzheimer's disease (AD) and neurodegeneration. In this review, we focus on understanding how diabetes contributes to the progression of neurodegeneration by influencing several aspects of the disease process. We emphasize the potential roles of brain insulin resistance, as well as cholesterol and lipid disruption, as factors which worsen AD.
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Affiliation(s)
- Joshua A Kulas
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, Virginia
| | - Thaddeus K Weigel
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Heather A Ferris
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, Virginia.,Department of Neuroscience, University of Virginia, Charlottesville, Virginia
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114
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Gralle M, Labrecque S, Salesse C, De Koninck P. Spatial dynamics of the insulin receptor in living neurons. J Neurochem 2020; 156:88-105. [PMID: 31886886 DOI: 10.1111/jnc.14950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/11/2019] [Accepted: 12/27/2019] [Indexed: 12/23/2022]
Abstract
Insulin signaling through the insulin receptor has long been studied in classic target organs, such as adipose tissue and skeletal muscle, where one of its effects is to increase glucose uptake. Insulin and insulin receptor are present in many areas of the brain, but the functions of brain insulin signaling outside feeding circuits are not well defined. It has been proposed that hippocampal insulin signaling is important for memory, that brain insulin signaling is deficient in Alzheimer's disease, and that intranasal insulin treatment improves cognition, but the mechanisms remain unclear and do not seem to involve increased glucose uptake by neurons. The molecular behavior of the insulin receptor itself is not well known in living neurons; therefore, we investigated the spatial dynamics of the insulin receptor on somatodendritic membranes of live rat hippocampal neurons in culture. Using single-molecule tracking of quantum dot-tagged insulin receptors and single-particle tracking photoactivation localization microscopy, we show that the insulin receptor is distributed over both dendritic shafts and spines. Using colocalization with synaptic markers, we also show that in contrast to the glutamate receptor subunit glutamate receptor subunit A1, the dynamics of the insulin receptor are not affected by association with excitatory synapses; however, the insulin receptor is immobilized by components of inhibitory synapses. The mobility of the insulin receptor is reduced both by low concentrations of the pro-inflammatory cytokine tumor necrosis factor α and by cholesterol depletion, suggesting an association with sphingolipid-rich membrane domains. On the other hand, the insulin receptor dynamics in hippocampal neurons are not affected by increased excitatory signaling. Finally, using real-time single-event quantification, we find evidence of strong insulin receptor exocytosis on dendritic shafts. Our results suggest an association of the neuronal insulin receptor with specific elements of the dendritic shaft, rather than excitatory synapses.
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Affiliation(s)
- Matthias Gralle
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,CERVO Brain Research Center, Québec, QC, Canada
| | | | | | - Paul De Koninck
- CERVO Brain Research Center, Québec, QC, Canada.,Département de biochimie, microbiologie et bio-informatique, Université Laval, Québec, QC, Canada
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115
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Liu S, Borgland SL. Insulin actions in the mesolimbic dopamine system. Exp Neurol 2019; 320:113006. [DOI: 10.1016/j.expneurol.2019.113006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/21/2019] [Accepted: 07/03/2019] [Indexed: 01/22/2023]
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116
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Bloch K, Gil-Ad I, Vanichkin A, Hornfeld SH, Taler M, Dar S, Azarov D, Vardi P, Weizman A. Intracranial Transplantation of Pancreatic Islets Attenuates Cognitive and Peripheral Metabolic Dysfunctions in a Rat Model of Sporadic Alzheimer's Disease. J Alzheimers Dis 2019; 65:1445-1458. [PMID: 30175977 DOI: 10.3233/jad-180623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is often associated with brain insulin resistance and peripheral metabolic dysfunctions. Recently, we developed a model of sporadic AD associated with obesity-related peripheral metabolic abnormalities in Lewis rats using intracerebroventricular administration of streptozotocin (icv-STZ). OBJECTIVE We aimed to assess the effect of intracranially grafted pancreatic islets on cognitive and peripheral metabolic dysfunctions in the icv-STZ Lewis rats. METHODS AD-like dementia associated with obesity was induced in inbred Lewis rats using a single icv-STZ. Two months after icv-STZ, syngeneic islets (100 islets per recipient) were implanted in the cranial subarachnoid cavity of icv-STZ rats. Morris water maze and marble burying tests were used for studying cognitive and behavioral functions. Central and peripheral metabolic alterations were assessed by histological and biochemical assays. RESULTS The icv-STZ induced increases in food intake, body weight, and blood levels of insulin and leptin without alteration of glucose homeostasis. Grafted islets reduced body weight gain, food consumption, peripheral insulin resistance, and hyperleptinemia. Biochemical and histological analysis of the brain revealed viable grafted islets expressing insulin and glucagon. The grafted islets did not affect expression of brain insulin receptors and peripheral glucose homeostasis. Two months after islet transplantation, cognitive and behavioral functioning in transplanted rats were significantly better than the sham-operated icv-STZ rats. No significant differences in the locomotor activity between transplanted and non-transplanted icv-STZ rats were found. CONCLUSIONS Intracranial islet transplantation attenuates cognitive decline and peripheral metabolic dysfunctions providing a novel therapeutic approach for sporadic AD associated with peripheral metabolic dysfunctions.
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Affiliation(s)
- Konstantin Bloch
- Laboratory of Diabetes and Obesity Research, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Irit Gil-Ad
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Alexey Vanichkin
- Laboratory of Transplantation, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Shay Henry Hornfeld
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Michal Taler
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Shira Dar
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Dmitry Azarov
- Laboratory of Diabetes and Obesity Research, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Pnina Vardi
- Laboratory of Diabetes and Obesity Research, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel
| | - Abraham Weizman
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Petah Tikva, Israel.,Research Unit, Geha Mental Health Center, Petah Tikva, Israel
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117
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Chudoba C, Wardelmann K, Kleinridders A. Molecular effects of dietary fatty acids on brain insulin action and mitochondrial function. Biol Chem 2019; 400:991-1003. [PMID: 30730834 DOI: 10.1515/hsz-2018-0477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 01/28/2019] [Indexed: 01/17/2023]
Abstract
The prevalence of obesity and its co-morbidities such as insulin resistance and type 2 diabetes are tightly linked to increased ingestion of palatable fat enriched food. Thus, it seems intuitive that the brain senses elevated amounts of fatty acids (FAs) and affects adaptive metabolic response, which is connected to mitochondrial function and insulin signaling. This review will address the effect of dietary FAs on brain insulin and mitochondrial function with a special emphasis on the impact of different FAs on brain function and metabolism.
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Affiliation(s)
- Chantal Chudoba
- Central Regulation of Metabolism, German Institute of Human Nutrition (DIfE), Arthur-Scheunert-Allee 114-116, D-14558 Nuthetal, Germany.,German Center for Diabetes Research (DZD), Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - Kristina Wardelmann
- Central Regulation of Metabolism, German Institute of Human Nutrition (DIfE), Arthur-Scheunert-Allee 114-116, D-14558 Nuthetal, Germany.,German Center for Diabetes Research (DZD), Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
| | - André Kleinridders
- Central Regulation of Metabolism, German Institute of Human Nutrition (DIfE), Arthur-Scheunert-Allee 114-116, D-14558 Nuthetal, Germany.,German Center for Diabetes Research (DZD), Ingolstädter Landstraße 1, D-85764 Neuherberg, Germany
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118
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Jeong JK, Horwath JA, Simonyan H, Blackmore KA, Butler SD, Young CN. Subfornical organ insulin receptors tonically modulate cardiovascular and metabolic function. Physiol Genomics 2019; 51:333-341. [PMID: 31172876 DOI: 10.1152/physiolgenomics.00021.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Insulin acts within the central nervous system through the insulin receptor to influence both metabolic and cardiovascular physiology. While a major focus has been placed on hypothalamic regions, participation of extrahypothalamic insulin receptors in cardiometabolic regulation remains largely unknown. We hypothesized that insulin receptors in the subfornical organ (SFO), a forebrain circumventricular region devoid of a blood-brain barrier, are involved in metabolic and cardiovascular regulation. Immunohistochemistry in mice revealed widespread insulin receptor-positive cells throughout the rostral to caudal extent of the SFO. SFO-targeted adenoviral delivery of Cre-recombinase in insulin receptorlox/lox mice resulted in sufficient ablation of insulin receptors in the SFO. Interestingly, when mice were maintained on a normal chow diet, deletion of SFO insulin receptors resulted in greater weight gain and adiposity, relative to controls, independently of changes in food intake. In line with this, ablation of insulin receptors in the SFO was associated with marked hepatic steatosis and hypertriglyceridemia. Selective removal of SFO insulin receptors also resulted in a lower mean arterial blood pressure, which was primarily due to a reduction in diastolic blood pressure, whereas systolic blood pressure remained unchanged. Cre-mediated targeting of SFO insulin receptors did not influence heart rate. These data demonstrate multidirectional roles for insulin receptor signaling in the SFO, with ablation of SFO insulin receptors resulting in an overall deleterious metabolic state while at the same time maintaining blood pressure at low levels. These novel findings further suggest that alterations in insulin receptor signaling in the SFO could contribute to metabolic syndrome phenotypes.
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Affiliation(s)
- Jin Kwon Jeong
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Julie A Horwath
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Katherine A Blackmore
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Scott D Butler
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
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119
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Zhou X, Xiao Q, Xie L, Yang F, Wang L, Tu J. Astrocyte, a Promising Target for Mood Disorder Interventions. Front Mol Neurosci 2019; 12:136. [PMID: 31231189 PMCID: PMC6560156 DOI: 10.3389/fnmol.2019.00136] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/09/2019] [Indexed: 01/03/2023] Open
Abstract
Mood disorders have multiple phenotypes and complex underlying biological mechanisms and, as such, there are no effective therapeutic strategies. A review of recent work on the role of astrocytes in mood disorders is thus warranted, which we embark on here. We argue that there is tremendous potential for novel strategies for therapeutic interventions based on the role of astrocytes. Astrocytes are traditionally considered to have supporting roles within the brain, yet emerging evidence has shown that astrocytes have more direct roles in influencing brain function. Notably, evidence from postmortem human brain tissues has highlighted changes in glial cell morphology, density and astrocyte-related biomarkers and genes following mood disorders, indicating astrocyte involvement in mood disorders. Findings from animal models strongly imply that astrocytes not only change astrocyte morphology and physiological characteristics but also influence neural circuits via synapse structure and formation. This review pays particular attention to interactions between astrocytes and neurons and argues that astrocyte dysfunction affects the monoaminergic system, excitatory–inhibitory balance and neurotrophic states of local networks. Together, these studies provide a foundation of knowledge about the exact role of astrocytes in mood disorders. Importantly, we then change the focus from neurons to glial cells and the interactions between the two, so that we can understand newly proposed mechanisms underlying mood disorders, and to identify more diagnostic indicators or effective targets for treatment of these diseases.
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Affiliation(s)
- Xinyi Zhou
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.,Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Qian Xiao
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.,Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Li Xie
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Fan Yang
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Liping Wang
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Jie Tu
- Shenzhen Key Lab of Neuropsychiatric Modulation, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
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120
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Rhea EM, Banks WA. Role of the Blood-Brain Barrier in Central Nervous System Insulin Resistance. Front Neurosci 2019; 13:521. [PMID: 31213970 PMCID: PMC6558081 DOI: 10.3389/fnins.2019.00521] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/06/2019] [Indexed: 01/01/2023] Open
Abstract
The blood-brain barrier (BBB) mediates the communication between the periphery and the central nervous system (CNS). Recently, CNS insulin resistance has been elucidated to play a role in neurodegenerative disease. This has stimulated a wealth of information on the molecular impact of insulin in the brain, particularly in the improvement of cognition. Since the BBB regulates the transport of insulin into the brain and thus, helps to regulate CNS levels, alterations in the BBB response to insulin could impact CNS insulin resistance. In this review, we summarize the effect of insulin on some of the cell types that make up the BBB, including endothelial cells, neurons, astrocytes, and pericytes. We broadly discuss how these changes in specific cell types could ultimately impact the BBB. We also summarize how insulin can regulate levels of the pathological hallmarks of Alzheimer's disease, including amyloid beta (Aβ) and tau within each cell type. Finally, we suggest interventional approaches to overcome detrimental effects on the BBB in regards to changes in insulin transport.
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Affiliation(s)
- Elizabeth M Rhea
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
| | - William A Banks
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
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121
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Choi I, Rickert E, Fernandez M, Webster NJG. SIRT1 in Astrocytes Regulates Glucose Metabolism and Reproductive Function. Endocrinology 2019; 160:1547-1560. [PMID: 31127273 PMCID: PMC6542483 DOI: 10.1210/en.2019-00223] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/19/2019] [Indexed: 12/13/2022]
Abstract
Sirtuin 1 (Sirt1) is an NAD-dependent class III deacetylase that functions as a cellular energy sensor. In addition to its well-characterized effects in peripheral tissues, evidence suggests that SIRT1 in neurons plays a role in the central regulation of energy balance and reproduction, but no studies have addressed the contribution of astrocytes. We show here that overexpression of SIRT1 in astrocytes causes markedly increased food intake, body weight gain, and glucose intolerance, but expression of a deacetylase-deficient SIRT1 mutant decreases food intake and body weight and improves glucose tolerance, particularly in female mice. Paradoxically, the effect of these SIRT1 mutants on insulin tolerance was reversed, with overexpression showing greater insulin sensitivity. The mice overexpressing SIRT1 were more active, generated more heat, and had elevated oxygen consumption, possibly in compensation for the increased food intake. The female overexpressing mice were also more sensitive to diet-induced obesity. Reproductively, the mice expressing the deacetylase-deficient SIRT1 mutant had impaired estrous cycles, decreased LH surges, and fewer corpora lutea, indicating decreased ovulation. The GnRH neurons were responsive to kisspeptin stimulation, but hypothalamic expression of Kiss1 was reduced in the mutant mice. Our results showed that SIRT1 signaling in astrocytes can contribute to metabolic and reproductive regulation independent of SIRT1 effects in neurons.
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Affiliation(s)
- Irene Choi
- VA San Diego Healthcare System, San Diego, California
| | - Emily Rickert
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California
| | - Marina Fernandez
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California
| | - Nicholas J G Webster
- VA San Diego Healthcare System, San Diego, California
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California
- Moores Cancer Center, University of California San Diego, La Jolla, California
- Correspondence: Nicholas J. G. Webster, PhD, Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093. E-mail:
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122
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Fuente-Martín E, Mellado-Gil JM, Cobo-Vuilleumier N, Martín-Montalvo A, Romero-Zerbo SY, Diaz Contreras I, Hmadcha A, Soria B, Martin Bermudo F, Reyes JC, Bermúdez-Silva FJ, Lorenzo PI, Gauthier BR. Dissecting the Brain/Islet Axis in Metabesity. Genes (Basel) 2019; 10:genes10050350. [PMID: 31072002 PMCID: PMC6562925 DOI: 10.3390/genes10050350] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 12/17/2022] Open
Abstract
The high prevalence of type 2 diabetes mellitus (T2DM), together with the fact that current treatments are only palliative and do not avoid major secondary complications, reveals the need for novel approaches to treat the cause of this disease. Efforts are currently underway to identify therapeutic targets implicated in either the regeneration or re-differentiation of a functional pancreatic islet β-cell mass to restore insulin levels and normoglycemia. However, T2DM is not only caused by failures in β-cells but also by dysfunctions in the central nervous system (CNS), especially in the hypothalamus and brainstem. Herein, we review the physiological contribution of hypothalamic neuronal and glial populations, particularly astrocytes, in the control of the systemic response that regulates blood glucose levels. The glucosensing capacity of hypothalamic astrocytes, together with their regulation by metabolic hormones, highlights the relevance of these cells in the control of glucose homeostasis. Moreover, the critical role of astrocytes in the response to inflammation, a process associated with obesity and T2DM, further emphasizes the importance of these cells as novel targets to stimulate the CNS in response to metabesity (over-nutrition-derived metabolic dysfunctions). We suggest that novel T2DM therapies should aim at stimulating the CNS astrocytic response, as well as recovering the functional pancreatic β-cell mass. Whether or not a common factor expressed in both cell types can be feasibly targeted is also discussed.
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Affiliation(s)
- Esther Fuente-Martín
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Jose M Mellado-Gil
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Nadia Cobo-Vuilleumier
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Alejandro Martín-Montalvo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Silvana Y Romero-Zerbo
- Instituto de Investigación Biomédica de Málaga-IBIMA, UGC Endocrinología y Nutrición. Hospital Regional Universitario de Málaga, 29009 Málaga, Spain.
| | - Irene Diaz Contreras
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Abdelkrim Hmadcha
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Bernat Soria
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Francisco Martin Bermudo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Jose C Reyes
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Francisco J Bermúdez-Silva
- Instituto de Investigación Biomédica de Málaga-IBIMA, UGC Endocrinología y Nutrición. Hospital Regional Universitario de Málaga, 29009 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Petra I Lorenzo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Benoit R Gauthier
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
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Bouyakdan K, Martin H, Liénard F, Budry L, Taib B, Rodaros D, Chrétien C, Biron É, Husson Z, Cota D, Pénicaud L, Fulton S, Fioramonti X, Alquier T. The gliotransmitter ACBP controls feeding and energy homeostasis via the melanocortin system. J Clin Invest 2019; 129:2417-2430. [PMID: 30938715 PMCID: PMC6546475 DOI: 10.1172/jci123454] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Glial cells have emerged as key players in the central control of energy balance and etiology of obesity. Astrocytes play a central role in neural communication via the release of gliotransmitters. Acyl-CoA binding protein (ACBP)-derived endozepines are secreted peptides that modulate the GABAA receptor. In the hypothalamus, ACBP is enriched in arcuate nucleus (ARC) astrocytes, ependymocytes and tanycytes. Central administration of the endozepine octadecaneuropeptide (ODN) reduces feeding and improves glucose tolerance, yet the contribution of endogenous ACBP in energy homeostasis is unknown. We demonstrated that ACBP deletion in GFAP+ astrocytes, but not in Nkx2.1-lineage neural cells, promoted diet-induced hyperphagia and obesity in both male and female mice, an effect prevented by viral rescue of ACBP in ARC astrocytes. ACBP-astrocytes were observed in apposition with proopiomelanocortin (POMC) neurons and ODN selectively activated POMC neurons through the ODN-GPCR but not GABAA, and supressed feeding while increasing carbohydrate utilization via the melanocortin system. Similarly, ACBP overexpression in ARC astrocytes reduced feeding and weight gain. Finally, the ODN-GPCR agonist decreased feeding and promoted weight loss in ob/ob mice. These findings uncover ACBP as an ARC gliopeptide playing a key role in energy balance control and exerting strong anorectic effects via the central melanocortin system.
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Affiliation(s)
- Khalil Bouyakdan
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine, Pathology and Cell Biology, Biochemistry, Neurosciences, and Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Hugo Martin
- Université de Bordeaux, INRA, NutriNeuro, Bordeaux, France
- Bordeaux INP, NutriNeuro, Talence, France
| | - Fabienne Liénard
- Centre des Sciences du Goût et de l’Alimentation, UMR 6265 CNRS, 1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
| | - Lionel Budry
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine, Pathology and Cell Biology, Biochemistry, Neurosciences, and Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Bouchra Taib
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine, Pathology and Cell Biology, Biochemistry, Neurosciences, and Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Demetra Rodaros
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine, Pathology and Cell Biology, Biochemistry, Neurosciences, and Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Chloé Chrétien
- Centre des Sciences du Goût et de l’Alimentation, UMR 6265 CNRS, 1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
| | - Éric Biron
- Faculty of Pharmacy, Université Laval and Laboratory of Medicinal Chemistry, Centre de Recherche du Centre Hospitalier Universitaire de Québec (CRCHUQ), Quebec, Quebec, Canada
| | - Zoé Husson
- Université de Bordeaux, INRA, NutriNeuro, Bordeaux, France
- Bordeaux INP, NutriNeuro, Talence, France
- INSERM, Université de Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, Bordeaux, France
| | - Daniela Cota
- INSERM, Université de Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, Bordeaux, France
| | - Luc Pénicaud
- Centre des Sciences du Goût et de l’Alimentation, UMR 6265 CNRS, 1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
- Stromalab, CNRS ERL 5311, Université de Toulouse, Université Paul Sabatier, Toulouse, France
| | - Stephanie Fulton
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine, Pathology and Cell Biology, Biochemistry, Neurosciences, and Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Xavier Fioramonti
- Université de Bordeaux, INRA, NutriNeuro, Bordeaux, France
- Bordeaux INP, NutriNeuro, Talence, France
- Centre des Sciences du Goût et de l’Alimentation, UMR 6265 CNRS, 1324 INRA, Université de Bourgogne Franche-Comté, Dijon, France
| | - Thierry Alquier
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal Diabetes Research Center, and Departments of Medicine, Pathology and Cell Biology, Biochemistry, Neurosciences, and Nutrition, Université de Montréal, Montreal, Quebec, Canada
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124
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Melo HM, Santos LE, Ferreira ST. Diet-Derived Fatty Acids, Brain Inflammation, and Mental Health. Front Neurosci 2019; 13:265. [PMID: 30983955 PMCID: PMC6448040 DOI: 10.3389/fnins.2019.00265] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/06/2019] [Indexed: 12/21/2022] Open
Abstract
Western societies experienced drastic changes in eating habits during the past century. The modern nutritional profile, typically rich in saturated fats and refined sugars, is recognized as a major contributing factor, along with reduced physical activity, to the current epidemics of metabolic disorders, notably obesity and diabetes. Alongside these conditions, recent years have witnessed a gradual and significant increase in prevalence of brain diseases, particularly mood disorders. While substantial clinical/epidemiological evidence supports a correlation between metabolic and neuropsychiatric disorders, the mechanisms of pathogenesis in the latter are often multifactorial and causal links have been hard to establish. Neuroinflammation stands out as a hallmark feature of brain disorders that may be linked to peripheral metabolic dyshomeostasis caused by an unhealthy diet. Dietary fatty acids are of particular interest, as they may play a dual role, both as a component of high-calorie obesogenic diets and as signaling molecules involved in inflammatory responses. Here, we review current literature connecting diet-related nutritional imbalance and neuropsychiatric disorders, focusing on the role of dietary fatty acids as signaling molecules directly relevant to inflammatory processes and to neuronal function.
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Affiliation(s)
- Helen M. Melo
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luís Eduardo Santos
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sergio T. Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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125
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Manaserh IH, Chikkamenahalli L, Ravi S, Dube PR, Park JJ, Hill JW. Ablating astrocyte insulin receptors leads to delayed puberty and hypogonadism in mice. PLoS Biol 2019; 17:e3000189. [PMID: 30893295 PMCID: PMC6443191 DOI: 10.1371/journal.pbio.3000189] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 04/01/2019] [Accepted: 03/05/2019] [Indexed: 11/18/2022] Open
Abstract
Insulin resistance and obesity are associated with reduced gonadotropin-releasing hormone (GnRH) release and infertility. Mice that lack insulin receptors (IRs) throughout development in both neuronal and non-neuronal brain cells are known to exhibit subfertility due to hypogonadotropic hypogonadism. However, attempts to recapitulate this phenotype by targeting specific neurons have failed. To determine whether astrocytic insulin sensing plays a role in the regulation of fertility, we generated mice lacking IRs in astrocytes (astrocyte-specific insulin receptor deletion [IRKOGFAP] mice). IRKOGFAP males and females showed a delay in balanopreputial separation or vaginal opening and first estrous, respectively. In adulthood, IRKOGFAP female mice also exhibited longer, irregular estrus cycles, decreased pregnancy rates, and reduced litter sizes. IRKOGFAP mice show normal sexual behavior but hypothalamic-pituitary-gonadotropin (HPG) axis dysregulation, likely explaining their low fecundity. Histological examination of testes and ovaries showed impaired spermatogenesis and ovarian follicle maturation. Finally, reduced prostaglandin E synthase 2 (PGES2) levels were found in astrocytes isolated from these mice, suggesting a mechanism for low GnRH/luteinizing hormone (LH) secretion. These findings demonstrate that insulin sensing by astrocytes is indispensable for the function of the reproductive axis. Additional work is needed to elucidate the role of astrocytes in the maturation of hypothalamic reproductive circuits.
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Affiliation(s)
- Iyad H Manaserh
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
- Center for Diabetes and Endocrine Research, University of Toledo, Toledo, Ohio, United States of America
| | - Lakshmikanth Chikkamenahalli
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Samyuktha Ravi
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Prabhatchandra R Dube
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Joshua J Park
- Center for Diabetes and Endocrine Research, University of Toledo, Toledo, Ohio, United States of America
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Jennifer W Hill
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
- Center for Diabetes and Endocrine Research, University of Toledo, Toledo, Ohio, United States of America
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126
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Morrill SJ, Gibas KJ. Ketogenic diet rescues cognition in ApoE4+ patient with mild Alzheimer's disease: A case study. Diabetes Metab Syndr 2019; 13:1187-1191. [PMID: 31336463 DOI: 10.1016/j.dsx.2019.01.035] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 01/18/2019] [Indexed: 11/16/2022]
Abstract
It has been established that there is a correlation between Alzheimer's disease and apolipoprotein E, specifically the ApoE4 genetic variant. However, the correlation between Apoe4, insulin resistance and metabolic syndrome (MetS) pathologies still remains elusive. As apolipoprotein E has many important physiological functions, individuals with the ApoE4 allele variant, also known as the Alzheimer's disease gene, are primarily at a greater risk for physiological consequences, specifically cognitive impairment (Chan et al., 2016). In this case study, a 71-year old female, heterozygous for ApoE4 with a family history of Alzheimer's Disease (AD) and the dual diagnosis of mild AD/metabolic syndrome (MetS) was placed on a 10-week nutrition protocol purposed at raising plasma ketones through carbohyrdrate restricted, high fat ketogenic diet (KD), time- restricted eating and physical/cognitive exercise. Primary biomarkers for MetS were measured pre/mid-/post intervention. The MoCA (Montreal Cognitive Assessment) was administered pre/post intervention by a licensed clinical therapist. The results were statistically significant. The HOMA-IR decreased by 75% from 13.9 to 3.48. Triglycerides decreased by 50% from 170mg/dL to 85mg/dL. VLDL dropped by 50% from 34mg/dL to 17mg/dL, and HgA1c decreased from 5.7% to 4.9%. The baseline MoCA score was 21/30; post treatment score was 28/30. The significant results in both MetS biomarkers and the MoCA score suggest that a ketogenic diet may serve to rescue cognition in patients with mild AD. The results of this case study are particularly compelling for ApoE4 positive (ApoE4+) subjects as ketogenic protocols extend hope and promise for AD prevention.
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Affiliation(s)
- Sarah J Morrill
- Human Bioenergetics & Applied Health Science, Bethel University, MN, USA
| | - Kelly J Gibas
- Behavioral Health Sciences, Human Bioenergetics & Applied Health Science, Bethel University, MN, USA.
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127
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Morita M, Ikeshima-Kataoka H, Kreft M, Vardjan N, Zorec R, Noda M. Metabolic Plasticity of Astrocytes and Aging of the Brain. Int J Mol Sci 2019; 20:ijms20040941. [PMID: 30795555 PMCID: PMC6413111 DOI: 10.3390/ijms20040941] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 01/03/2023] Open
Abstract
As part of the blood-brain-barrier, astrocytes are ideally positioned between cerebral vasculature and neuronal synapses to mediate nutrient uptake from the systemic circulation. In addition, astrocytes have a robust enzymatic capacity of glycolysis, glycogenesis and lipid metabolism, managing nutrient support in the brain parenchyma for neuronal consumption. Here, we review the plasticity of astrocyte energy metabolism under physiologic and pathologic conditions, highlighting age-dependent brain dysfunctions. In astrocytes, glycolysis and glycogenesis are regulated by noradrenaline and insulin, respectively, while mitochondrial ATP production and fatty acid oxidation are influenced by the thyroid hormone. These regulations are essential for maintaining normal brain activities, and impairments of these processes may lead to neurodegeneration and cognitive decline. Metabolic plasticity is also associated with (re)activation of astrocytes, a process associated with pathologic events. It is likely that the recently described neurodegenerative and neuroprotective subpopulations of reactive astrocytes metabolize distinct energy substrates, and that this preference is supposed to explain some of their impacts on pathologic processes. Importantly, physiologic and pathologic properties of astrocytic metabolic plasticity bear translational potential in defining new potential diagnostic biomarkers and novel therapeutic targets to mitigate neurodegeneration and age-related brain dysfunctions.
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Affiliation(s)
- Mitsuhiro Morita
- Department of Biology, Graduate School of Sciences, Kobe University, 657-8501 Kobe, Japan.
| | - Hiroko Ikeshima-Kataoka
- Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
| | - Marko Kreft
- Laboratory of Cell Engineering, Celica Biomedical, 1000 Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
- Department of Biology, Biotechnical Faculty University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Nina Vardjan
- Laboratory of Cell Engineering, Celica Biomedical, 1000 Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica Biomedical, 1000 Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Mami Noda
- Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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128
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Insulin signaling in the hippocampus and amygdala regulates metabolism and neurobehavior. Proc Natl Acad Sci U S A 2019; 116:6379-6384. [PMID: 30765523 DOI: 10.1073/pnas.1817391116] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Previous studies have shown that insulin and IGF-1 signaling in the brain, especially the hypothalamus, is important for regulation of systemic metabolism. Here, we develop mice in which we have specifically inactivated both insulin receptors (IRs) and IGF-1 receptors (IGF1Rs) in the hippocampus (Hippo-DKO) or central amygdala (CeA-DKO) by stereotaxic delivery of AAV-Cre into IRlox/lox/IGF1Rlox/lox mice. Consequently, both Hippo-DKO and CeA-DKO mice have decreased levels of the GluA1 subunit of glutamate AMPA receptor and display increased anxiety-like behavior, impaired cognition, and metabolic abnormalities, including glucose intolerance. Hippo-DKO mice also display abnormal spatial learning and memory whereas CeA-DKO mice have impaired cold-induced thermogenesis. Thus, insulin/IGF-1 signaling has common roles in the hippocampus and central amygdala, affecting synaptic function, systemic glucose homeostasis, behavior, and cognition. In addition, in the hippocampus, insulin/IGF-1 signaling is important for spatial learning and memory whereas insulin/IGF-1 signaling in the central amygdala controls thermogenesis via regulation of neural circuits innervating interscapular brown adipose tissue.
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129
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Lyra E Silva NDM, Lam MP, Soares CN, Munoz DP, Milev R, De Felice FG. Insulin Resistance as a Shared Pathogenic Mechanism Between Depression and Type 2 Diabetes. Front Psychiatry 2019; 10:57. [PMID: 30837902 PMCID: PMC6382695 DOI: 10.3389/fpsyt.2019.00057] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 01/25/2019] [Indexed: 12/28/2022] Open
Abstract
Neuropsychiatric disorders and type 2 diabetes (T2D) are major public health concerns proposed to be intimately connected. T2D is associated with increased risk of dementia, neuropsychiatric and mood disorders. Evidences of the involvement of insulin signaling on brain mechanisms related to depression indicate that insulin resistance, a hallmark of type 2 diabetes, could develop in the brains of depressive patients. In this article, we briefly review possible molecular mechanisms associating defective brain insulin signaling with reward system, neurogenesis, synaptic plasticity and hypothalamic-pituitary-adrenal (HPA) stress axis in depression. We further discuss the involvement of tumor necrosis factor α (TNFα) promoting defective insulin signaling and depressive-like behavior in rodent models. Finally, due to the high resistant rate of anti-depressants, novel insights into the link between insulin resistance and depression may advance the development of alternative treatments for this disease.
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Affiliation(s)
| | - Minh P Lam
- Department of Psychiatry, Queen's University, Kingston, ON, Canada
| | - Claudio N Soares
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.,Department of Psychiatry, Queen's University, Kingston, ON, Canada
| | - Douglas P Munoz
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Roumen Milev
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.,Department of Psychiatry, Queen's University, Kingston, ON, Canada
| | - Fernanda G De Felice
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.,Department of Psychiatry, Queen's University, Kingston, ON, Canada.,Institute of Medical Biochemistry Leopoldo De Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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130
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Naef L, Seabrook L, Hsiao J, Li C, Borgland SL. Insulin in the ventral tegmental area reduces cocaine-evoked dopamine in the nucleus accumbens in vivo. Eur J Neurosci 2018; 50:2146-2155. [PMID: 30471157 DOI: 10.1111/ejn.14291] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 02/06/2023]
Abstract
Mesolimbic dopamine circuits, implicated in incentive motivation, are sensitive to changes in metabolic state such as weight loss and diet-induced obesity. These neurons are important targets for metabolic hormones such as leptin, glucagon-like peptide-1, ghrelin and insulin. Insulin receptors are located on dopamine neurons in the ventral tegmental area (VTA) and we have previously demonstrated that insulin induces long-term depression of excitatory synapses onto VTA dopamine neurons. While insulin can decrease dopamine concentration in somatodendritic regions, it can increase dopamine in striatal slices. Whether insulin directly targets the VTA to alter dopamine release in projection areas, such as the nucleus accumbens (NAc), remains unknown. The main goal of the present experiments was to examine NAc dopamine concentration following VTA administration of insulin. Using in vivo FSCV to detect rapid fluctuations in dopamine concentration, we showed that intra-VTA insulin via action at insulin receptors reduced pedunculopontine nucleus-evoked dopamine release in the NAc. Furthermore, intra-VTA insulin reduced cocaine-potentiated NAc dopamine. Finally, intra-VTA or intranasal insulin decreased locomotor responses to cocaine, an effect blocked by an intra-VTA administered insulin receptor antagonist. Together, these data demonstrate that mesolimbic dopaminergic projections are important targets of the metabolic hormone, insulin.
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Affiliation(s)
- Lindsay Naef
- Department of Physiology & Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Lauren Seabrook
- Department of Physiology & Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Jeff Hsiao
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Calvin Li
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephanie L Borgland
- Department of Physiology & Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
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131
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Ferreira LSS, Fernandes CS, Vieira MNN, De Felice FG. Insulin Resistance in Alzheimer's Disease. Front Neurosci 2018; 12:830. [PMID: 30542257 PMCID: PMC6277874 DOI: 10.3389/fnins.2018.00830] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/23/2018] [Indexed: 12/22/2022] Open
Abstract
The epidemiological connection between diabetes, obesity, and dementia represents an important public health challenge but also an opportunity to further understand these conditions. The key intersection among the three diseases is insulin resistance, which has been classically described to occur in peripheral tissues in diabetes and obesity and has recently been shown to develop in Alzheimer's disease (AD) brains. Here we review encouraging preclinical and clinical data indicating the potential of targeting impaired insulin signaling with antidiabetic drugs to treat dementia. We further discuss biological mechanisms through which peripheral metabolic dysregulation may lead to brain malfunction, providing possible explanations for the connection between diabetes, obesity, and AD. Finally, we briefly discuss how lifelong allostatic load may interact with aging to increase the risk of dementia in late life.
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Affiliation(s)
- Laís S. S. Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Caroline S. Fernandes
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo N. N. Vieira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda G. De Felice
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Biomedical and Molecular Sciences, Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
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