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Jaykumar AB, Binns D, Taylor CA, Anselmo A, Birnbaum SG, Huber KM, Cobb MH. WNKs regulate mouse behavior and alter central nervous system glucose uptake and insulin signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.09.598125. [PMID: 38915673 PMCID: PMC11195145 DOI: 10.1101/2024.06.09.598125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Certain areas of the brain involved in episodic memory and behavior, such as the hippocampus, express high levels of insulin receptors and glucose transporter-4 (GLUT4) and are responsive to insulin. Insulin and neuronal glucose metabolism improve cognitive functions and regulate mood in humans. Insulin-dependent GLUT4 trafficking has been extensively studied in muscle and adipose tissue, but little work has demonstrated either how it is controlled in insulin-responsive brain regions or its mechanistic connection to cognitive functions. In this study, we demonstrate that inhibition of WNK (With-No-lysine (K)) kinases improves learning and memory in mice. Neuronal inhibition of WNK enhances in vivo hippocampal glucose uptake. Inhibition of WNK enhances insulin signaling output and insulin-dependent GLUT4 trafficking to the plasma membrane in mice primary neuronal cultures and hippocampal slices. Therefore, we propose that the extent of neuronal WNK kinase activity has an important influence on learning, memory and anxiety-related behaviors, in part, by modulation of neuronal insulin signaling.
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Affiliation(s)
- Ankita B. Jaykumar
- Departments of Pharmacology, UT Southwestern Medical Center, Dallas, USA
| | - Derk Binns
- Departments of Pharmacology, UT Southwestern Medical Center, Dallas, USA
| | - Clinton A. Taylor
- Departments of Pharmacology, UT Southwestern Medical Center, Dallas, USA
| | - Anthony Anselmo
- Departments of Pharmacology, UT Southwestern Medical Center, Dallas, USA
| | - Shari G. Birnbaum
- Departments of Peter O’Donnell Jr. Brain Institute and Psychiatry, UT Southwestern Medical Center, Dallas, USA
| | | | - Melanie H. Cobb
- Departments of Pharmacology, UT Southwestern Medical Center, Dallas, USA
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2
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Stark R. The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism. J Neuroendocrinol 2024; 36:e13382. [PMID: 38468186 DOI: 10.1111/jne.13382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/13/2024]
Abstract
Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.
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Affiliation(s)
- Romana Stark
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
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3
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Kula B, Antal B, Weistuch C, Gackière F, Barre A, Velado V, Hubbard JM, Kukley M, Mujica-Parodi LR, Smith NA. D-β-hydroxybutyrate stabilizes hippocampal CA3-CA1 circuit during acute insulin resistance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.23.554428. [PMID: 37662316 PMCID: PMC10473684 DOI: 10.1101/2023.08.23.554428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The brain primarily relies on glycolysis for mitochondrial respiration but switches to alternative fuels such as ketone bodies (KBs) when less glucose is available. Neuronal KB uptake, which does not rely on glucose transporter 4 (GLUT4) or insulin, has shown promising clinical applicability in alleviating the neurological and cognitive effects of disorders with hypometabolic components. However, the specific mechanisms by which such interventions affect neuronal functions are poorly understood. In this study, we pharmacologically blocked GLUT4 to investigate the effects of exogenous KB D-β-hydroxybutyrate (D-βHb) on mouse brain metabolism during acute insulin resistance (AIR). We found that both AIR and D-βHb had distinct impacts across neuronal compartments: AIR decreased synaptic activity and long-term potentiation (LTP) and impaired axonal conduction, synchronization, and action potential (AP) properties, while D-βHb rescued neuronal functions associated with axonal conduction, synchronization, and LTP.
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Affiliation(s)
- Bartosz Kula
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, USA
| | - Botond Antal
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - Corey Weistuch
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Florian Gackière
- Neuroservices Alliance, Les Jardins de l’Entreprise, Quartier de le Confrérie, Le Puy Ste Réparade, France
| | - Alexander Barre
- Neuroservices Alliance, Les Jardins de l’Entreprise, Quartier de le Confrérie, Le Puy Ste Réparade, France
| | - Victor Velado
- Center for Neuroscience Research, Children’s National Research Institute, Children’s National Hospital, Washington D.C., USA
| | - Jeffrey M Hubbard
- Neuroservices Alliance, Les Jardins de l’Entreprise, Quartier de le Confrérie, Le Puy Ste Réparade, France
| | - Maria Kukley
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Ikerbasque - Basque Foundation for Science, Bilbao, Spain
| | - Lilianne R Mujica-Parodi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, USA
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, USA
| | - Nathan A Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, USA
- Center for Neuroscience Research, Children’s National Research Institute, Children’s National Hospital, Washington D.C., USA
- George Washington University School of Medicine and Health Sciences, Washington D.C., USA
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4
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Kula B, Antal B, Weistuch C, Gackière F, Barre A, Velado V, Hubbard JM, Kukley M, Mujica-Parodi LR, Smith NA. D-ꞵ-hydroxybutyrate stabilizes hippocampal CA3-CA1 circuit during acute insulin resistance. PNAS NEXUS 2024; 3:pgae196. [PMID: 38818236 PMCID: PMC11138115 DOI: 10.1093/pnasnexus/pgae196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/06/2024] [Indexed: 06/01/2024]
Abstract
The brain primarily relies on glycolysis for mitochondrial respiration but switches to alternative fuels such as ketone bodies (KBs) when less glucose is available. Neuronal KB uptake, which does not rely on glucose transporter 4 (GLUT4) or insulin, has shown promising clinical applicability in alleviating the neurological and cognitive effects of disorders with hypometabolic components. However, the specific mechanisms by which such interventions affect neuronal functions are poorly understood. In this study, we pharmacologically blocked GLUT4 to investigate the effects of exogenous KB D-ꞵ-hydroxybutyrate (D-ꞵHb) on mouse brain metabolism during acute insulin resistance (AIR). We found that both AIR and D-ꞵHb had distinct impacts across neuronal compartments: AIR decreased synaptic activity and long-term potentiation (LTP) and impaired axonal conduction, synchronization, and action potential properties, while D-ꞵHb rescued neuronal functions associated with axonal conduction, synchronization, and LTP.
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Affiliation(s)
- Bartosz Kula
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Botond Antal
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
| | - Corey Weistuch
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Florian Gackière
- Neuroservices Alliance, Les Jardins de l’Entreprise, Quartier de le Confrérie, 13610 Le Puy-Sainte-Réparade, France
| | - Alexander Barre
- Neuroservices Alliance, Les Jardins de l’Entreprise, Quartier de le Confrérie, 13610 Le Puy-Sainte-Réparade, France
| | - Victor Velado
- Center for Neuroscience Research, Children’s National Research Institute, Children’s National Hospital, Washington, DC 20012, USA
| | - Jeffrey M Hubbard
- Neuroservices Alliance, Les Jardins de l’Entreprise, Quartier de le Confrérie, 13610 Le Puy-Sainte-Réparade, France
| | - Maria Kukley
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Bizkaia, Spain
- Ikerbasque—Basque Foundation for Science, 48009 Bilbao, Spain
| | - Lilianne R Mujica-Parodi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nathan A Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA
- Center for Neuroscience Research, Children’s National Research Institute, Children’s National Hospital, Washington, DC 20012, USA
- School of Medicine and Health Sciences, George Washington University, Washington, DC 20052, USA
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5
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Chen K, Yu G. Tetrahydroalstonine possesses protective potentials on palmitic acid stimulated SK-N-MC cells by suppression of Aβ1-42 and tau through regulation of PI3K/Akt signaling pathway. Eur J Pharmacol 2024; 962:176251. [PMID: 38061471 DOI: 10.1016/j.ejphar.2023.176251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/25/2023] [Accepted: 11/30/2023] [Indexed: 12/20/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease. The morbidity of Alzheimer's disease is currently on the rise worldwide, but no effective treatment is available. Cornus officinalis is an herb and edible plant used in traditional Chinese medicine, whose extract has neuroprotective properties. In this investigation, we endeavored to refine a systems pharmacology strategy combining bioinformatics analysis, drug prediction, network pharmacology, and molecular docking to screen tetrahydroalstonine (THA) from Cornus officinalis as a therapeutic component for AD. Subsequent in vitro experiments were validated using MTT assay, Annexin V-PI flow cytometry, Western blotting, and immunofluorescence analysis. In Palmitate acid-induced SK-N-MC cells, THA restored the impaired PI3K/AKT signaling pathway, regulated insulin resistance, and attenuated BACE1 and GSK3β activity. In addition, THA significantly reduced cell apoptosis rate, down-regulated relative levels of p-JNK/JNK, Bax/Bcl-2, cytochrome C, active caspase-3 and caspase-3, and attenuated Palmitate acid-induced Aβ1-42 and Tau generation. THA may regulate the phenotype of AD and reduce cell apoptosis by modulating the PI3K/AKT signaling pathway. This systematic analysis provides new ramifications concerning the therapeutic utility of tetrahydroalstonine for AD.
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Affiliation(s)
- Kang Chen
- Department of Neurology, Jiangsu Traditional Chinese Medicine Hospital, The Affiliated Hospital of Nanjing University of Traditional Chinese Medicine, Nanjing, 210029, PR China
| | - Guran Yu
- Department of Neurology, Jiangsu Traditional Chinese Medicine Hospital, The Affiliated Hospital of Nanjing University of Traditional Chinese Medicine, Nanjing, 210029, PR China.
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6
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Kueck PJ, Morris JK, Stanford JA. Current Perspectives: Obesity and Neurodegeneration - Links and Risks. Degener Neurol Neuromuscul Dis 2023; 13:111-129. [PMID: 38196559 PMCID: PMC10774290 DOI: 10.2147/dnnd.s388579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/21/2023] [Indexed: 01/11/2024] Open
Abstract
Obesity is increasing in prevalence across all age groups. Long-term obesity can lead to the development of metabolic and cardiovascular diseases through its effects on adipose, skeletal muscle, and liver tissue. Pathological mechanisms associated with obesity include immune response and inflammation as well as oxidative stress and consequent endothelial and mitochondrial dysfunction. Recent evidence links obesity to diminished brain health and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Both AD and PD are associated with insulin resistance, an underlying syndrome of obesity. Despite these links, causative mechanism(s) resulting in neurodegenerative disease remain unclear. This review discusses relationships between obesity, AD, and PD, including clinical and preclinical findings. The review then briefly explores nonpharmacological directions for intervention.
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Affiliation(s)
- Paul J Kueck
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Jill K Morris
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - John A Stanford
- University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, 66160, USA
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, 66160, USA
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7
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Yonamine CY, Michalani MLE, Moreira RJ, Machado UF. Glucose Transport and Utilization in the Hippocampus: From Neurophysiology to Diabetes-Related Development of Dementia. Int J Mol Sci 2023; 24:16480. [PMID: 38003671 PMCID: PMC10671460 DOI: 10.3390/ijms242216480] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
The association of diabetes with cognitive dysfunction has at least 60 years of history, which started with the observation that children with type 1 diabetes mellitus (T1D), who had recurrent episodes of hypoglycemia and consequently low glucose supply to the brain, showed a deficit of cognitive capacity. Later, the growing incidence of type 2 diabetes mellitus (T2D) and dementia in aged populations revealed their high association, in which a reduced neuronal glucose supply has also been considered as a key mechanism, despite hyperglycemia. Here, we discuss the role of glucose in neuronal functioning/preservation, and how peripheral blood glucose accesses the neuronal intracellular compartment, including the exquisite glucose flux across the blood-brain barrier (BBB) and the complex network of glucose transporters, in dementia-related areas such as the hippocampus. In addition, insulin resistance-induced abnormalities in the hippocampus of obese/T2D patients, such as inflammatory stress, oxidative stress, and mitochondrial stress, increased generation of advanced glycated end products and BBB dysfunction, as well as their association with dementia/Alzheimer's disease, are addressed. Finally, we discuss how these abnormalities are accompained by the reduction in the expression and translocation of the high capacity insulin-sensitive glucose transporter GLUT4 in hippocampal neurons, which leads to neurocytoglycopenia and eventually to cognitive dysfunction. This knowledge should further encourage investigations into the beneficial effects of promising therapeutic approaches which could improve central insulin sensitivity and GLUT4 expression, to fight diabetes-related cognitive dysfunctions.
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Affiliation(s)
- Caio Yogi Yonamine
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark;
| | - Maria Luiza Estimo Michalani
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (M.L.E.M.); (R.J.M.)
| | - Rafael Junges Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (M.L.E.M.); (R.J.M.)
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (M.L.E.M.); (R.J.M.)
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8
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Kim DY, Park J, Han IO. Hexosamine biosynthetic pathway and O-GlcNAc cycling of glucose metabolism in brain function and disease. Am J Physiol Cell Physiol 2023; 325:C981-C998. [PMID: 37602414 DOI: 10.1152/ajpcell.00191.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/03/2023] [Accepted: 08/03/2023] [Indexed: 08/22/2023]
Abstract
Impaired brain glucose metabolism is considered a hallmark of brain dysfunction and neurodegeneration. Disruption of the hexosamine biosynthetic pathway (HBP) and subsequent O-linked N-acetylglucosamine (O-GlcNAc) cycling has been identified as an emerging link between altered glucose metabolism and defects in the brain. Myriads of cytosolic and nuclear proteins in the nervous system are modified at serine or threonine residues with a single N-acetylglucosamine (O-GlcNAc) molecule by O-GlcNAc transferase (OGT), which can be removed by β-N-acetylglucosaminidase (O-GlcNAcase, OGA). Homeostatic regulation of O-GlcNAc cycling is important for the maintenance of normal brain activity. Although significant evidence linking dysregulated HBP metabolism and aberrant O-GlcNAc cycling to induction or progression of neuronal diseases has been obtained, the issue of whether altered O-GlcNAcylation is causal in brain pathogenesis remains uncertain. Elucidation of the specific functions and regulatory mechanisms of individual O-GlcNAcylated neuronal proteins in both normal and diseased states may facilitate the identification of novel therapeutic targets for various neuronal disorders. The information presented in this review highlights the importance of HBP/O-GlcNAcylation in the neuronal system and summarizes the roles and potential mechanisms of O-GlcNAcylated neuronal proteins in maintaining normal brain function and initiation and progression of neurological diseases.
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Affiliation(s)
- Dong Yeol Kim
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, South Korea
| | - Jiwon Park
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, South Korea
| | - Inn-Oc Han
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, South Korea
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9
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Contreras CM, Gutiérrez-García AG. Insulin and fluoxetine produce opposite actions on lateral septal nucleus-infralimbic region connection responsivity. Behav Brain Res 2023; 437:114146. [PMID: 36202146 DOI: 10.1016/j.bbr.2022.114146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/28/2022] [Accepted: 10/02/2022] [Indexed: 11/07/2022]
Abstract
Some diabetes patients develop depression, the main treatment for which is antidepressants. Pharmacological interactions between insulin and antidepressants (e.g., fluoxetine) are controversial in the literature. Some authors reported hypoglycemic actions of fluoxetine, whereas others reported antidepressant-like actions. In healthy rats, insulin produces an antidespair-like action in rats through an increase in locomotor and exploratory activity, but differences in actions of insulin and fluoxetine on neuronal activity are unknown. The present study evaluated Wistar healthy rats that were treated with saline, insulin, fluoxetine, or fluoxetine + insulin for 3 days (short-term) or 21 days (long-term). The model consisted of electrical stimulation of the lateral septal nucleus (LSN) while we performed single-unit extracellular response recordings in the prelimbic cortex (PL) and infralimbic cortex (IL) subregions of the medial prefrontal cortex (mPFC). Stimulation of the LSN produced an initial brief excitatory paucisynaptic response and then a long-lasting inhibitory afterdischarge in the PL and IL. Treatment with saline and fluoxetine, but not insulin, minimally affected the paucisynaptic response. Differences were found in LSN-IL responsivity. The inhibitory afterdischarge was clearly enhanced in the long-term fluoxetine group but not by insulin alone or fluoxetine + insulin. These findings suggest that insulin produces some actions that are opposite to fluoxetine on LSN-mPFC connection responsivity, with no synergistic actions between the actions of insulin and fluoxetine.
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Affiliation(s)
- Carlos M Contreras
- Unidad Periférica del Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Xalapa, Veracruz 91190, Mexico.
| | - Ana G Gutiérrez-García
- Laboratorio de Neurofarmacología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz 91190, Mexico
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Wei J, Yang B, Wang R, Ye H, Wang Y, Wang L, Zhang X. Risk of stroke and retinopathy during GLP-1 receptor agonist cardiovascular outcome trials: An eight RCTs meta-analysis. Front Endocrinol (Lausanne) 2022; 13:1007980. [PMID: 36545339 PMCID: PMC9760859 DOI: 10.3389/fendo.2022.1007980] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 11/16/2022] [Indexed: 12/12/2022] Open
Abstract
Purpose To explore the risk of stroke (including ischemic and hemorrhagic stroke) in type 2 diabetes mellitus treated with glucagon-like peptide 1 receptor agonist (GLP-1RA) medication according to data from the Cardiovascular Outcome Trials(CVOT). Methods Randomized controlled trials (RCT) on GLP-1RA therapy and cardiovascular outcomes in type 2 diabetics published in full-text journal databases such as Medline (via PubMed), Embase, Clinical Trials.gov, and the Cochrane Library from establishment to May 1, 2022 were searched. We assess the quality of individual studies by using the Cochrane risk of bias algorithm. RevMan 5.4.1 software was use for calculating meta- analysis. Results A total of 60,081 randomized participants were included in the data of these 8 GLP-1RA cardiovascular outcomes trials. Pooled analysis reported statistically significant effect on total stroke risk[RR=0.83, 95%CI(0.73, 0.95), p=0.005], and its subtypes such as ischemic Stroke [RR=0.83, 95%CI(0.73, 0.95), p=0.008] from treatment with GLP-1RA versus placebo, and have no significant effect on the risk of hemorrhagic stroke[RR=0.83, 95%CI(0.57, 1.20), p=0.31] and retinopathy [RR=1.54, 95%CI(0.74, 3.23), p=0.25]. Conclusion GLP-1RA significantly reduces the risk of ischemic stroke in type 2 diabetics with cardiovascular risk factors.
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Affiliation(s)
- Jinjing Wei
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Bing Yang
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Ruxin Wang
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Haowen Ye
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Ying Wang
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lihong Wang
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Jinan University, Guangzhou, China
- The Guangzhou Key Laboratory of Basic and Translational Research on Chronic Diseases, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Xiaofang Zhang
- Department Clinical Experimental Center, First Affiliated Hospital of Jinan University, Guangzhou, China
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11
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Baltaci SB, Unal O, Gulbahce-Mutlu E, Gumus H, Pehlivanoglu S, Yardimci A, Mogulkoc R, Baltaci AK. The Role of Zinc Status on Spatial Memory, Hippocampal Synaptic Plasticity, and Insulin Signaling in icv-STZ-Induced Sporadic Alzheimer's-Like Disease in Rats. Biol Trace Elem Res 2022; 200:4068-4078. [PMID: 34727320 DOI: 10.1007/s12011-021-02999-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 10/26/2021] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD), especially its sporadic form (sAD), is of multifactorial nature. Brain insulin resistance and disrupted zinc homeostasis are two key aspects of AD that remain to be elucidated. Here, we investigated the effects of dietary zinc deficiency and supplementation on memory, hippocampal synaptic plasticity, and insulin signaling in intracerebroventricular streptozotocin (icv-STZ)-induced sAD in rats. The memory performance was evaluated by Morris water maze. The expression of hippocampal protein and mRNA levels of targets related to synaptic plasticity and insulin pathway was assessed by Western blot and real-time quantitative PCR. We found memory deficits in icv-STZ rats, which were fully recovered by zinc supplementation. Western blot analysis revealed that icv-STZ treatment significantly reduced hippocampal PSD95 and p-GSK3β, and zinc supplementation restored the normal protein levels. mRNA levels of BDNF, PSD95, SIRT1, GLUT4, insulin receptor, and ZnT3 were found to be reduced by icv-STZ and reestablished by zinc supplementation. Our data suggest that zinc supplementation improves cognitive deficits and rescues the decline in key molecular targets of synaptic plasticity and insulin signaling in hippocampus caused by icv-STZ induced sAD in rats.
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Affiliation(s)
- Saltuk Bugra Baltaci
- Department of Physiology, Medical Faculty, Selçuk University, Konya, 42031, Turkey
| | - Omer Unal
- Department of Physiology, Medical Faculty, Selçuk University, Konya, 42031, Turkey
| | - Elif Gulbahce-Mutlu
- Department of Medical Biology, Medical Faculty, KTO Karatay University, Konya, Turkey
| | - Haluk Gumus
- Department of Neurology, Medical Faculty, Selçuk University, Konya, Turkey
| | - Suray Pehlivanoglu
- Department of Molecular Biology, Science Faculty, Necmettin Erbakan University, Konya, Turkey
| | - Ahmet Yardimci
- Department of Physiology, Medical Faculty, Firat University, Elazig, Turkey
| | - Rasim Mogulkoc
- Department of Physiology, Medical Faculty, Selçuk University, Konya, 42031, Turkey
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12
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Piccialli I, Tedeschi V, Caputo L, D’Errico S, Ciccone R, De Feo V, Secondo A, Pannaccione A. Exploring the Therapeutic Potential of Phytochemicals in Alzheimer’s Disease: Focus on Polyphenols and Monoterpenes. Front Pharmacol 2022; 13:876614. [PMID: 35600880 PMCID: PMC9114803 DOI: 10.3389/fphar.2022.876614] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/11/2022] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD) is a chronic, complex neurodegenerative disorder mainly characterized by the irreversible loss of memory and cognitive functions. Different hypotheses have been proposed thus far to explain the etiology of this devastating disorder, including those centered on the Amyloid-β (Aβ) peptide aggregation, Tau hyperphosphorylation, neuroinflammation and oxidative stress. Nonetheless, the therapeutic strategies conceived thus far to treat AD neurodegeneration have proven unsuccessful, probably due to the use of single-target drugs unable to arrest the progressive deterioration of brain functions. For this reason, the theoretical description of the AD etiology has recently switched from over-emphasizing a single deleterious process to considering AD neurodegeneration as the result of different pathogenic mechanisms and their interplay. Moreover, much relevance has recently been conferred to several comorbidities inducing insulin resistance and brain energy hypometabolism, including diabetes and obesity. As consequence, much interest is currently accorded in AD treatment to a multi-target approach interfering with different pathways at the same time, and to life-style interventions aimed at preventing the modifiable risk-factors strictly associated with aging. In this context, phytochemical compounds are emerging as an enormous source to draw on in the search for multi-target agents completing or assisting the traditional pharmacological medicine. Intriguingly, many plant-derived compounds have proven their efficacy in counteracting several pathogenic processes such as the Aβ aggregation, neuroinflammation, oxidative stress and insulin resistance. Many strategies have also been conceived to overcome the limitations of some promising phytochemicals related to their poor pharmacokinetic profiles, including nanotechnology and synthetic routes. Considering the emerging therapeutic potential of natural medicine, the aim of the present review is therefore to highlight the most promising phytochemical compounds belonging to two major classes, polyphenols and monoterpenes, and to report the main findings about their mechanisms of action relating to the AD pathogenesis.
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Affiliation(s)
- Ilaria Piccialli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Valentina Tedeschi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Lucia Caputo
- Department of Pharmacy, University of Salerno, Salerno, Italy
| | - Stefano D’Errico
- Department of Pharmacy, University of Naples “Federico II”, Naples, Italy
| | - Roselia Ciccone
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Vincenzo De Feo
- Department of Pharmacy, University of Salerno, Salerno, Italy
| | - Agnese Secondo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Anna Pannaccione
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
- *Correspondence: Anna Pannaccione,
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13
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Henkel ND, Wu X, O'Donovan SM, Devine EA, Jiron JM, Rowland LM, Sarnyai Z, Ramsey AJ, Wen Z, Hahn MK, McCullumsmith RE. Schizophrenia: a disorder of broken brain bioenergetics. Mol Psychiatry 2022; 27:2393-2404. [PMID: 35264726 DOI: 10.1038/s41380-022-01494-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 02/07/2023]
Abstract
A substantial and diverse body of literature suggests that the pathophysiology of schizophrenia is related to deficits of bioenergetic function. While antipsychotics are an effective therapy for the management of positive psychotic symptoms, they are not efficacious for the complete schizophrenia symptom profile, such as the negative and cognitive symptoms. In this review, we discuss the relationship between dysfunction of various metabolic pathways across different brain regions in relation to schizophrenia. We contend that several bioenergetic subprocesses are affected across the brain and such deficits are a core feature of the illness. We provide an overview of central perturbations of insulin signaling, glycolysis, pentose-phosphate pathway, tricarboxylic acid cycle, and oxidative phosphorylation in schizophrenia. Importantly, we discuss pharmacologic and nonpharmacologic interventions that target these pathways and how such interventions may be exploited to improve the symptoms of schizophrenia.
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Affiliation(s)
- Nicholas D Henkel
- Department of Neurosciences, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA.
| | - Xiajoun Wu
- Department of Neurosciences, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Sinead M O'Donovan
- Department of Neurosciences, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Emily A Devine
- Department of Neurosciences, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Jessica M Jiron
- Department of Neurosciences, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Laura M Rowland
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Zoltan Sarnyai
- Laboratory of Psychiatric Neuroscience, Australian Institute for Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia
| | - Amy J Ramsey
- Department of Pharmacology and Toxicology, Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Zhexing Wen
- Departments of Psychiatry and Behavioral Sciences, Cell Biology, and Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Margaret K Hahn
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Robert E McCullumsmith
- Department of Neurosciences, The University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
- Neurosciences Institute, ProMedica, Toledo, OH, USA
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Abstract
The Akt isoforms-AS160-GLUT4 axis is the primary axis that governs glucose homeostasis in the body. The first step on the path to insulin resistance is deregulated Akt isoforms. This could be Akt isoform expression, its phosphorylation, or improper isoform-specific redistribution to the plasma membrane in a specific tissue system. The second step is deregulated AS160 expression, its phosphorylation, improper dissociation from glucose transporter storage vesicles (GSVs), or its inability to bind to 14-3-3 proteins, thus not allowing it to execute its function. The final step is improper GLUT4 translocation and aberrant glucose uptake. These processes lead to insulin resistance in a tissue-specific way affecting the whole-body glucose homeostasis, eventually progressing to an overt diabetic phenotype. Thus, the relationship between these three key proteins and their proper regulation comes out as the defining axis of insulin signaling and -resistance. This review summarizes the role of this central axis in insulin resistance and disease in a new light.
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Affiliation(s)
- Medha Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi, 110016, India
| | - Chinmoy Sankar Dey
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi, 110016, India.
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15
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Milstein JL, Ferris HA. The brain as an insulin-sensitive metabolic organ. Mol Metab 2021; 52:101234. [PMID: 33845179 PMCID: PMC8513144 DOI: 10.1016/j.molmet.2021.101234] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/26/2021] [Accepted: 04/07/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The brain was once thought of as an insulin-insensitive organ. We now know that the insulin receptor is present throughout the brain and serves important functions in whole-body metabolism and brain function. Brain insulin signaling is involved not only in brain homeostatic processes but also neuropathological processes such as cognitive decline and Alzheimer's disease. SCOPE OF REVIEW In this review, we provide an overview of insulin signaling within the brain and the metabolic impact of brain insulin resistance and discuss Alzheimer's disease, one of the neurologic diseases most closely associated with brain insulin resistance. MAJOR CONCLUSIONS While brain insulin signaling plays only a small role in central nervous system glucose regulation, it has a significant impact on the brain's metabolic health. Normal insulin signaling is important for mitochondrial functioning and normal food intake. Brain insulin resistance contributes to obesity and may also play an important role in neurodegeneration.
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Affiliation(s)
- Joshua L Milstein
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA, USA; Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Heather A Ferris
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, VA, USA; Department of Neuroscience, University of Virginia, Charlottesville, VA, USA; Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA.
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16
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Brain Glucose Transporters: Role in Pathogenesis and Potential Targets for the Treatment of Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms22158142. [PMID: 34360906 PMCID: PMC8348194 DOI: 10.3390/ijms22158142] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/06/2021] [Accepted: 07/28/2021] [Indexed: 12/16/2022] Open
Abstract
The most common cause of dementia, especially in elderly people, is Alzheimer’s disease (AD), with aging as its main risk factor. AD is a multifactorial neurodegenerative disease. There are several factors increasing the risk of AD development. One of the main features of Alzheimer’s disease is impairment of brain energy. Hypometabolism caused by decreased glucose uptake is observed in specific areas of the AD-affected brain. Therefore, glucose hypometabolism and energy deficit are hallmarks of AD. There are several hypotheses that explain the role of glucose hypometabolism in AD, but data available on this subject are poor. Reduced transport of glucose into neurons may be related to decreased expression of glucose transporters in neurons and glia. On the other hand, glucose transporters may play a role as potential targets for the treatment of AD. Compounds such as antidiabetic drugs, agonists of SGLT1, insulin, siRNA and liposomes are suggested as therapeutics. Nevertheless, the suggested targets of therapy need further investigations.
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17
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Kyrtata N, Emsley HCA, Sparasci O, Parkes LM, Dickie BR. A Systematic Review of Glucose Transport Alterations in Alzheimer's Disease. Front Neurosci 2021; 15:626636. [PMID: 34093108 PMCID: PMC8173065 DOI: 10.3389/fnins.2021.626636] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/22/2021] [Indexed: 12/12/2022] Open
Abstract
Introduction: Alzheimer's disease (AD) is characterized by cerebral glucose hypometabolism. Hypometabolism may be partly due to reduced glucose transport at the blood-brain barrier (BBB) and across astrocytic and neuronal cell membranes. Glucose transporters (GLUTs) are integral membrane proteins responsible for moving glucose from the bloodstream to parenchymal cells where it is metabolized, and evidence indicates vascular and non-vascular GLUTs are altered in AD brains, a process which could starve the brain of glucose and accelerate cognitive decline. Here we review the literature on glucose transport alterations in AD from human and rodent studies. Methods: Literature published between 1st January 1946 and 1st November 2020 within EMBASE and MEDLINE databases was searched for the terms "glucose transporters" AND "Alzheimer's disease". Human and rodent studies were included while reviews, letters, and in-vitro studies were excluded. Results: Forty-three studies fitting the inclusion criteria were identified, covering human (23 studies) and rodent (20 studies). Post-mortem studies showed consistent reductions in GLUT1 and GLUT3 in the hippocampus and cortex of AD brains, areas of the brain closely associated with AD pathology. Tracer studies in rodent models of AD and human AD also exhibit reduced uptake of glucose and glucose-analogs into the brain, supporting these findings. Longitudinal rodent studies clearly indicate that changes in GLUT1 and GLUT3 only occur after amyloid-β pathology is present, and several studies indicate amyloid-β itself may be responsible for GLUT changes. Furthermore, evidence from human and rodent studies suggest GLUT depletion has severe effects on brain function. A small number of studies show GLUT2 and GLUT12 are increased in AD. Anti-diabetic medications improved glucose transport capacity in AD subjects. Conclusions: GLUT1 and GLUT3 are reduced in hippocampal and cortical regions in patients and rodent models of AD, and may be caused by high levels of amyloid-β in these regions. GLUT3 reductions appear to precede the onset of clinical symptoms. GLUT2 and GLUT12 appear to increase and may have a compensatory role. Repurposing anti-diabetic drugs to modify glucose transport shows promising results in human studies of AD.
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Affiliation(s)
- Natalia Kyrtata
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
- University Hospitals of Morecambe Bay NHS Foundation Trust, Lancaster, United Kingdom
| | - Hedley C. A. Emsley
- Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
- Department of Neurology, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
| | - Oli Sparasci
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
- Greater Manchester Mental Health NHS Foundation Trust, Manchester, United Kingdom
| | - Laura M. Parkes
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Ben R. Dickie
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, United Kingdom
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18
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Zhao ZH, Du KJ, Wang T, Wang JY, Cao ZP, Chen XM, Song H, Zheng G, Shen XF. Maternal Lead Exposure Impairs Offspring Learning and Memory via Decreased GLUT4 Membrane Translocation. Front Cell Dev Biol 2021; 9:648261. [PMID: 33718391 PMCID: PMC7947239 DOI: 10.3389/fcell.2021.648261] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/08/2021] [Indexed: 11/13/2022] Open
Abstract
Lead (Pb) can cause a significant neurotoxicity in both adults and children, leading to the impairment to brain function. Pb exposure plays a key role in the impairment of learning and memory through synaptic neurotoxicity, resulting in the cognitive function. Researches have demonstrated that Pb exposure plays an important role in the etiology and pathogenesis of neurodegenerative diseases, such as Alzheimer's disease. However, the underlying mechanisms remain unclear. In the current study, a gestational Pb exposure (GLE) rat model was established to investigate the underlying mechanisms of Pb-induced cognitive impairment. We demonstrated that low-level gestational Pb exposure impaired spatial learning and memory as well as hippocampal synaptic plasticity at postnatal day 30 (PND 30) when the blood concentration of Pb had already recovered to normal levels. Pb exposure induced a decrease in hippocampal glucose metabolism by reducing glucose transporter 4 (GLUT4) levels in the cell membrane through the phosphatidylinositol 3 kinase-protein kinase B (PI3K-Akt) pathway. In vivo and in vitro GLUT4 over-expression increased the membrane translocation of GLUT4 and glucose uptake, and reversed the Pb-induced impairment to synaptic plasticity and cognition. These findings indicate that Pb exposure impairs synaptic plasticity by reducing the level of GLUT4 in the cell membrane as well as glucose uptake via the PI3K-Akt signaling pathway, demonstrating a novel mechanism for Pb exposure-induced neurotoxicity.
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Affiliation(s)
- Zai-Hua Zhao
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Ke-Jun Du
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Tao Wang
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Ji-Ye Wang
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Zi-Peng Cao
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Xiao-Ming Chen
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Han Song
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China.,Department of Health Service, Chinese PLA General Hospital, Beijing, China
| | - Gang Zheng
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
| | - Xue-Feng Shen
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, China
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19
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Głuchowska K, Pliszka M, Szablewski L. Expression of glucose transporters in human neurodegenerative diseases. Biochem Biophys Res Commun 2021; 540:8-15. [PMID: 33429199 DOI: 10.1016/j.bbrc.2020.12.067] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 12/18/2020] [Indexed: 10/22/2022]
Abstract
The central nervous system (CNS) plays an important role in the human body. It is involved in the receive, store and participation in information retrieval. It can use several substrates as a source of energy, however, the main source of energy is glucose. Cells of the central nervous system need a continuous supply of energy, therefore, transport of glucose into these cells is very important. There are three distinct families of glucose transporters: sodium-independent glucose transporters (GLUTs), sodium-dependent glucose cotransporters (SGLTs), and uniporter, SWEET protein. In the human brain only GLUTs and SGLTs were detected. In neurodegenerative diseases was observed hypometabolism of glucose due to decreased expression of glucose transporters, in particular GLUT1 and GLUT3. On the other hand, animal studies revealed, that increased levels of these glucose transporters, due to for example by the increased copy number of SLC2A genes, may have a beneficial effect and may be a targeted therapy in the treatment of patients with AD, HD and PD.
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Affiliation(s)
- Kinga Głuchowska
- Medical University of Warsaw, Chair and Department of General Biology and Parasitology, 5 Chalubinskiego Str., 02-004 Warsaw, Poland.
| | - Monika Pliszka
- Medical University of Warsaw, Chair and Department of General Biology and Parasitology, 5 Chalubinskiego Str., 02-004 Warsaw, Poland.
| | - Leszek Szablewski
- Medical University of Warsaw, Chair and Department of General Biology and Parasitology, 5 Chalubinskiego Str., 02-004 Warsaw, Poland.
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20
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Glucose transporters in brain in health and disease. Pflugers Arch 2020; 472:1299-1343. [PMID: 32789766 PMCID: PMC7462931 DOI: 10.1007/s00424-020-02441-x] [Citation(s) in RCA: 219] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022]
Abstract
Energy demand of neurons in brain that is covered by glucose supply from the blood is ensured by glucose transporters in capillaries and brain cells. In brain, the facilitative diffusion glucose transporters GLUT1-6 and GLUT8, and the Na+-d-glucose cotransporters SGLT1 are expressed. The glucose transporters mediate uptake of d-glucose across the blood-brain barrier and delivery of d-glucose to astrocytes and neurons. They are critically involved in regulatory adaptations to varying energy demands in response to differing neuronal activities and glucose supply. In this review, a comprehensive overview about verified and proposed roles of cerebral glucose transporters during health and diseases is presented. Our current knowledge is mainly based on experiments performed in rodents. First, the functional properties of human glucose transporters expressed in brain and their cerebral locations are described. Thereafter, proposed physiological functions of GLUT1, GLUT2, GLUT3, GLUT4, and SGLT1 for energy supply to neurons, glucose sensing, central regulation of glucohomeostasis, and feeding behavior are compiled, and their roles in learning and memory formation are discussed. In addition, diseases are described in which functional changes of cerebral glucose transporters are relevant. These are GLUT1 deficiency syndrome (GLUT1-SD), diabetes mellitus, Alzheimer’s disease (AD), stroke, and traumatic brain injury (TBI). GLUT1-SD is caused by defect mutations in GLUT1. Diabetes and AD are associated with changed expression of glucose transporters in brain, and transporter-related energy deficiency of neurons may contribute to pathogenesis of AD. Stroke and TBI are associated with changes of glucose transporter expression that influence clinical outcome.
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21
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Deme P, Rojas C, Slusher BS, Rais R, Afghah Z, Geiger JD, Haughey NJ. Bioenergetic adaptations to HIV infection. Could modulation of energy substrate utilization improve brain health in people living with HIV-1? Exp Neurol 2020; 327:113181. [PMID: 31930991 PMCID: PMC7233457 DOI: 10.1016/j.expneurol.2020.113181] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 12/10/2019] [Accepted: 01/10/2020] [Indexed: 12/18/2022]
Abstract
The human brain consumes more energy than any other organ in the body and it relies on an uninterrupted supply of energy in the form of adenosine triphosphate (ATP) to maintain normal cognitive function. This constant supply of energy is made available through an interdependent system of metabolic pathways in neurons, glia and endothelial cells that each have specialized roles in the delivery and metabolism of multiple energetic substrates. Perturbations in brain energy metabolism is associated with a number of different neurodegenerative conditions including impairments in cognition associated with infection by the Human Immunodeficiency Type 1 Virus (HIV-1). Adaptive changes in brain energy metabolism are apparent early following infection, do not fully normalize with the initiation of antiretroviral therapy (ART), and often worsen with length of infection and duration of anti-retroviral therapeutic use. There is now a considerable amount of cumulative evidence that suggests mild forms of cognitive impairments in people living with HIV-1 (PLWH) may be reversible and are associated with specific modifications in brain energy metabolism. In this review we discuss brain energy metabolism with an emphasis on adaptations that occur in response to HIV-1 infection. The potential for interventions that target brain energy metabolism to preserve or restore cognition in PLWH are also discussed.
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Affiliation(s)
- Pragney Deme
- The Johns Hopkins University School of Medicine, Department of Neurology, United States
| | - Camilo Rojas
- The Johns Hopkins University School of Medicine, Department of Comparative Medicine and Pathobiology, United States
| | - Barbara S Slusher
- The Johns Hopkins University School of Medicine, Department of Neurology, United States; The Johns Hopkins University School of Medicine, Department of The Solomon H. Snyder Department of Neuroscience, United States; The Johns Hopkins University School of Medicine, Department of Comparative Medicine and Pathobiology, United States; The Johns Hopkins University School of Medicine, Department of Psychiatry, United States
| | - Raina Rais
- The Johns Hopkins University School of Medicine, Department of Neurology, United States; The Johns Hopkins University School of Medicine, Department of The Solomon H. Snyder Department of Neuroscience, United States; The Johns Hopkins University School of Medicine, Department of Comparative Medicine and Pathobiology, United States; The Johns Hopkins University School of Medicine, Department of Psychiatry, United States
| | - Zahra Afghah
- The University of North Dakota School of Medicine and Health Sciences, Department of Biomedical Sciences, United States
| | - Jonathan D Geiger
- The University of North Dakota School of Medicine and Health Sciences, Department of Biomedical Sciences, United States
| | - Norman J Haughey
- The Johns Hopkins University School of Medicine, Department of Neurology, United States; The Johns Hopkins University School of Medicine, Department of Psychiatry, United States.
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22
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McNay EC, Pearson-Leary J. GluT4: A central player in hippocampal memory and brain insulin resistance. Exp Neurol 2020; 323:113076. [PMID: 31614121 PMCID: PMC6936336 DOI: 10.1016/j.expneurol.2019.113076] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/19/2019] [Accepted: 10/01/2019] [Indexed: 12/24/2022]
Abstract
Insulin is now well-established as playing multiple roles within the brain, and specifically as regulating hippocampal cognitive processes and metabolism. Impairments to insulin signaling, such as those seen in type 2 diabetes and Alzheimer's disease, are associated with brain hypometabolism and cognitive impairment, but the mechanisms of insulin's central effects are not determined. Several lines of research converge to suggest that the insulin-responsive glucose transporter GluT4 plays a central role in hippocampal memory processes, and that reduced activation of this transporter may underpin the cognitive impairments seen as a consequence of insulin resistance.
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Affiliation(s)
- Ewan C McNay
- Behavioral Neuroscience, University at Albany, Albany, NY, USA.
| | - Jiah Pearson-Leary
- Department of Anesthesiology, Abramson Research Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
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23
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Tetramethylpyrazine prevents diabetes by activating PI3K/Akt/GLUT-4 signalling in animal model of type-2 diabetes. Life Sci 2019; 236:116836. [DOI: 10.1016/j.lfs.2019.116836] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/22/2019] [Accepted: 09/03/2019] [Indexed: 12/16/2022]
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24
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Rai U, Kosuru R, Prakash S, Tiwari V, Singh S. Tetramethylpyrazine alleviates diabetic nephropathy through the activation of Akt signalling pathway in rats. Eur J Pharmacol 2019; 865:172763. [PMID: 31682792 DOI: 10.1016/j.ejphar.2019.172763] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/15/2019] [Accepted: 10/29/2019] [Indexed: 11/28/2022]
Abstract
In the whole world, the principal cause of end-stage renal disease is diabetic nephropathy (DN), which is one of the most relentless complications of diabetes. However, there is a shortfall of compelling DN treatments and the mechanism potentially able to alleviate renal injury remains ambiguous. In this experiment, we estimated the preventive actions of tetramethylpyrazine (TMP) on DN in rats and further investigated the underlying mechanism. The different doses of TMP (100 mg/kg, 150 mg/kg and 200 mg/kg) were orally given each day for 8 weeks in streptozotocin (STZ) - nicotinamide (NCT) - induced type-2 diabetic (T2D) rats. The metabolic parameters of diabetes, blood urea nitrogen (BUN), serum creatinine (SCR), urinary protein and oxidative stress parameters were assessed. Microstructural changes in kidney were observed, and the expression of Akt signalling pathway proteins was measured by western blotting. TMP administration in T2D rats improved diabetic condition, as demonstrated by significant (P < 0.05) increase of body weight and fasting serum insulin (FSI) level, reduction of fasting blood glucose (FBG) and glycosylated haemoglobin (HbA1c) level and regulation of lipid profile and oral glucose tolerance in a dose-dependent manner. TMP treatment also reduced BUN, SCR, urinary protein and oxidative stress and prevented renal injury in diabetic rats. TMP activated Akt signalling pathway, increased the levels of p-Akt and Bcl-2, and diminished the expressions of p-GSK-3β, Bax and cleaved caspase-3. In conclusion, TMP ameliorates diabetic nephropathy in T2D rats by initiating the Akt signalling, improving the metabolic markers of diabetes and suppressing oxidative stress.
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Affiliation(s)
- Uddipak Rai
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (BHU), Varanasi, 221005, India
| | - Ramoji Kosuru
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (BHU), Varanasi, 221005, India
| | - Swati Prakash
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (BHU), Varanasi, 221005, India
| | - Vinod Tiwari
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (BHU), Varanasi, 221005, India.
| | - Sanjay Singh
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (BHU), Varanasi, 221005, India.
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Tiani KA, Stover PJ, Field MS. The Role of Brain Barriers in Maintaining Brain Vitamin Levels. Annu Rev Nutr 2019; 39:147-173. [DOI: 10.1146/annurev-nutr-082018-124235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is increasingly recognized that tissue-specific nutrient deficiencies can exist in the absence of whole-body deficiency and that these deficiencies may result from disease or disease-related physiological processes. Brain and central nervous system tissues require adequate nutrient levels to function. Many nutrients are concentrated in the cerebrospinal fluid relative to the serum in healthy individuals, and other nutrients resist depletion in the presence of whole-body nutrient depletion. The endothelial, epithelial, and arachnoid brain barriers work in concert to selectively transport, concentrate, and maintain levels of the specific nutrients required by the brain while also blocking the passage of blood-borne toxins and pathogens to brain and central nervous system tissues. These barriers preserve nutrient levels within the brain and actively concentrate nutrients within the cerebrospinal fluid and brain. The roles of physical and energetic barriers, including the blood–brain and blood–nerve barriers, in maintaining brain nutrient levels in health and disease are discussed.
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Affiliation(s)
- Kendra A. Tiani
- Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA
| | - Patrick J. Stover
- College of Agriculture and Life Sciences, Texas A & M University, College Station, Texas 77843-2142, USA
| | - Martha S. Field
- Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA
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26
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Metabolic perturbations after pediatric TBI: It's not just about glucose. Exp Neurol 2019; 316:74-84. [PMID: 30951705 DOI: 10.1016/j.expneurol.2019.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/13/2019] [Accepted: 03/30/2019] [Indexed: 12/22/2022]
Abstract
Improved patient survival following pediatric traumatic brain injury (TBI) has uncovered a currently limited understanding of both the adaptive and maladaptive metabolic perturbations that occur during the acute and long-term phases of recovery. While much is known about the redundancy of metabolic pathways that provide adequate energy and substrates for normal brain growth and development, the field is only beginning to characterize perturbations in these metabolic pathways after pediatric TBI. To date, the majority of studies have focused on dysregulated oxidative glucose metabolism after injury; however, the immature brain is well-equipped to use alternative substrates to fuel energy production, growth, and development. A comprehensive understanding of metabolic changes associated with pediatric TBI cannot be limited to investigations of glucose metabolism alone. All energy substrates used by the brain should be considered in developing nutritional and pharmacological interventions for pediatric head trauma. This review summarizes post-injury changes in brain metabolism of glucose, lipids, ketone bodies, and amino acids with discussion of the therapeutic potential of altering substrate utilization to improve pediatric TBI outcomes.
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Hypothyroidism Causes Endoplasmic Reticulum Stress in Adult Rat Hippocampus: A Mechanism Associated with Hippocampal Damage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2089404. [PMID: 29743975 PMCID: PMC5884203 DOI: 10.1155/2018/2089404] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/14/2018] [Accepted: 03/01/2018] [Indexed: 01/15/2023]
Abstract
Thyroid hormones (TH) are essential for hippocampal neuronal viability in adulthood, and their deficiency causes hypothyroidism, which is related to oxidative stress events and neuronal damage. Also, it has been hypothesized that hypothyroidism causes a glucose deprivation in the neuron. This study is aimed at evaluating the temporal participation of the endoplasmic reticulum stress (ERE) in hippocampal neurons of adult hypothyroid rats and its association with the oxidative stress events. Adult Wistar male rats were divided into euthyroid and hypothyroid groups. Thyroidectomy with parathyroid gland reimplementation caused hypothyroidism at three weeks postsurgery. Oxidative stress, redox environment, and antioxidant enzyme markers, as well as the expression of the ERE through the pathways of PERK, ATF6, and IRE1, were evaluated at the 3rd and 4th weeks postsurgery. We found a rise in ROS and nitrite production; also, catalase increased and glutathione peroxidase diminished their activities. These events promote an enhancement of the lipoperoxidation, as well as of γ-GT, myeloperoxidase, and caspase 3 activities. With respect to ERE, there were ATF6, IRE1, and GADD153 overexpressions with a reduction in mitochondrial activity and GSH2/GSSG ratio. We conclude that the endoplasmic reticulum stress might play a pivotal role in the activation of hypothyroidism-induced hippocampal cell death.
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28
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Koekkoek LL, Mul JD, la Fleur SE. Glucose-Sensing in the Reward System. Front Neurosci 2017; 11:716. [PMID: 29311793 PMCID: PMC5742113 DOI: 10.3389/fnins.2017.00716] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 12/07/2017] [Indexed: 01/14/2023] Open
Abstract
Glucose-sensing neurons are neurons that alter their activity in response to changes in extracellular glucose. These neurons, which are an important mechanism the brain uses to monitor changes in glycaemia, are present in the hypothalamus, where they have been thoroughly investigated. Recently, glucose-sensing neurons have also been identified in brain nuclei which are part of the reward system. However, little is known about the molecular mechanisms by which they function, and their role in the reward system. We therefore aim to provide an overview of molecular mechanisms that have been studied in the hypothalamic glucose-sensing neurons, and investigate which of these transporters, enzymes and channels are present in the reward system. Furthermore, we speculate about the role of glucose-sensing neurons in the reward system.
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Affiliation(s)
- Laura L Koekkoek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Laboratory of Endocrinology, Department of Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Metabolism and Reward Group, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
| | - Joram D Mul
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Laboratory of Endocrinology, Department of Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Metabolism and Reward Group, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
| | - Susanne E la Fleur
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Laboratory of Endocrinology, Department of Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Metabolism and Reward Group, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands
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29
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Insulin modulates hippocampally-mediated spatial working memory via glucose transporter-4. Behav Brain Res 2017; 338:32-39. [PMID: 28943428 DOI: 10.1016/j.bbr.2017.09.033] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/15/2017] [Accepted: 09/20/2017] [Indexed: 01/04/2023]
Abstract
The insulin-regulated glucose transporter, GluT4, is a key molecule in peripheral insulin signaling. Although GluT4 is abundantly expressed in neurons of specific brain regions such as the hippocampus, the functional role of neuronal GluT4 is unclear. Here, we used pharmacological inhibition of GluT4-mediated glucose uptake to determine whether GluT4 mediates insulin-mediated glucose uptake in the hippocampus. Consistent with previous reports, we found that glucose utilization increased in the dorsal hippocampus of male rats during spontaneous alternation (SA), a hippocampally-mediated spatial working memory task. We previously showed that insulin signaling within the hippocampus is required for processing this task, and that administration of exogenous insulin enhances performance. At baseline levels of hippocampal insulin, inhibition of GluT4-mediated glucose uptake did not affect SA performance. However, inhibition of an upstream regulator of GluT4, Akt, did impair SA performance. Conversely, when a memory-enhancing dose of insulin was delivered to the hippocampus prior to SA-testing, inhibition of GluT4-mediated glucose transport prevented cognitive enhancement. These data suggest that baseline hippocampal cognitive processing does not require functional hippocampal GluT4, but that cognitive enhancement by supra-baseline insulin does. Consistent with these findings, we found that in neuronal cell culture, insulin increases glucose utilization in a GluT4-dependent manner. Collectively, these data demonstrate a key role for GluT4 in transducing the procognitive effects of elevated hippocampal insulin.
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30
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Novel Roles for the Insulin-Regulated Glucose Transporter-4 in Hippocampally Dependent Memory. J Neurosci 2017; 36:11851-11864. [PMID: 27881773 DOI: 10.1523/jneurosci.1700-16.2016] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/15/2016] [Accepted: 09/20/2016] [Indexed: 11/21/2022] Open
Abstract
The insulin-regulated glucose transporter-4 (GluT4) is critical for insulin- and contractile-mediated glucose uptake in skeletal muscle. GluT4 is also expressed in some hippocampal neurons, but its functional role in the brain is unclear. Several established molecular modulators of memory processing regulate hippocampal GluT4 trafficking and hippocampal memory formation is limited by both glucose metabolism and insulin signaling. Therefore, we hypothesized that hippocampal GluT4 might be involved in memory processes. Here, we show that, in male rats, hippocampal GluT4 translocates to the plasma membrane after memory training and that acute, selective intrahippocampal inhibition of GluT4-mediated glucose transport impaired memory acquisition, but not memory retrieval. Other studies have shown that prolonged systemic GluT4 blockade causes insulin resistance. Unexpectedly, we found that prolonged hippocampal blockade of glucose transport through GluT4-upregulated markers of hippocampal insulin signaling prevented task-associated depletion of hippocampal glucose and enhanced both working and short-term memory while also impairing long-term memory. These effects were accompanied by increased expression of hippocampal AMPA GluR1 subunits and the neuronal GluT3, but decreased expression of hippocampal brain-derived neurotrophic factor, consistent with impaired ability to form long-term memories. Our findings are the first to show the cognitive impact of brain GluT4 modulation. They identify GluT4 as a key regulator of hippocampal memory processing and also suggest differential regulation of GluT4 in the hippocampus from that in peripheral tissues. SIGNIFICANCE STATEMENT The role of insulin-regulated glucose transporter-4 (GluT4) in the brain is unclear. In the current study, we demonstrate that GluT4 is a critical component of hippocampal memory processes. Memory training increased hippocampal GluT4 translocation and memory acquisition was impaired by GluT4 blockade. Unexpectedly, whereas long-term inhibition of GluT4 impaired long-term memory, short-term memory was enhanced. These data further our understanding of the molecular mechanisms of memory and have particular significance for type 2 diabetes (in which GluT4 activity in the periphery is impaired) and Alzheimer's disease (which is linked to impaired brain insulin signaling and for which type 2 diabetes is a key risk factor). Both diseases cause marked impairment of hippocampal memory linked to hippocampal hypometabolism, suggesting the possibility that brain GluT4 dysregulation may be one cause of cognitive impairment in these disease states.
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31
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Julliard AK, Al Koborssy D, Fadool DA, Palouzier-Paulignan B. Nutrient Sensing: Another Chemosensitivity of the Olfactory System. Front Physiol 2017; 8:468. [PMID: 28747887 PMCID: PMC5506222 DOI: 10.3389/fphys.2017.00468] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/19/2017] [Indexed: 12/31/2022] Open
Abstract
Olfaction is a major sensory modality involved in real time perception of the chemical composition of the external environment. Olfaction favors anticipation and rapid adaptation of behavioral responses necessary for animal survival. Furthermore, recent studies have demonstrated that there is a direct action of metabolic peptides on the olfactory network. Orexigenic peptides such as ghrelin and orexin increase olfactory sensitivity, which in turn, is decreased by anorexigenic hormones such as insulin and leptin. In addition to peptides, nutrients can play a key role on neuronal activity. Very little is known about nutrient sensing in olfactory areas. Nutrients, such as carbohydrates, amino acids, and lipids, could play a key role in modulating olfactory sensitivity to adjust feeding behavior according to metabolic need. Here we summarize recent findings on nutrient-sensing neurons in olfactory areas and delineate the limits of our knowledge on this topic. The present review opens new lines of investigations on the relationship between olfaction and food intake, which could contribute to determining the etiology of metabolic disorders.
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Affiliation(s)
- A-Karyn Julliard
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/Centre National de la Recherche Scientifique UMR5292 Team Olfaction: From Coding to MemoryLyon, France
| | - Dolly Al Koborssy
- Department of Biological Science, Florida State UniversityTallahassee, FL, United States.,Program in Neuroscience, Florida State UniversityTallahassee, FL, United States
| | - Debra A Fadool
- Department of Biological Science, Florida State UniversityTallahassee, FL, United States.,Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Institute of Molecular Biophysics, Florida State UniversityTallahassee, FL, United States
| | - Brigitte Palouzier-Paulignan
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/Centre National de la Recherche Scientifique UMR5292 Team Olfaction: From Coding to MemoryLyon, France
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32
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Reno CM, Puente EC, Sheng Z, Daphna-Iken D, Bree AJ, Routh VH, Kahn BB, Fisher SJ. Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation. Diabetes 2017; 66:587-597. [PMID: 27797912 PMCID: PMC5319720 DOI: 10.2337/db16-0917] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/12/2016] [Indexed: 12/12/2022]
Abstract
GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose.
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Affiliation(s)
- Candace M Reno
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St. Louis, St. Louis, MO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Internal Medicine, University of Utah, Salt Lake City, UT
| | - Erwin C Puente
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St. Louis, St. Louis, MO
| | - Zhenyu Sheng
- Department of Pharmacology and Physiology, Rutgers New Jersey Medical School, Newark, NJ
| | - Dorit Daphna-Iken
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St. Louis, St. Louis, MO
| | - Adam J Bree
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St. Louis, St. Louis, MO
| | - Vanessa H Routh
- Department of Pharmacology and Physiology, Rutgers New Jersey Medical School, Newark, NJ
| | - Barbara B Kahn
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Simon J Fisher
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University in St. Louis, St. Louis, MO
- Division of Endocrinology, Metabolism, and Diabetes, Department of Internal Medicine, University of Utah, Salt Lake City, UT
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33
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Weiler A, Volkenhoff A, Hertenstein H, Schirmeier S. Metabolite transport across the mammalian and insect brain diffusion barriers. Neurobiol Dis 2017; 107:15-31. [PMID: 28237316 DOI: 10.1016/j.nbd.2017.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 01/02/2017] [Accepted: 02/20/2017] [Indexed: 12/31/2022] Open
Abstract
The nervous system in higher vertebrates is separated from the circulation by a layer of specialized endothelial cells. It protects the sensitive neurons from harmful blood-derived substances, high and fluctuating ion concentrations, xenobiotics or even pathogens. To this end, the brain endothelial cells and their interlinking tight junctions build an efficient diffusion barrier. A structurally analogous diffusion barrier exists in insects, where glial cell layers separate the hemolymph from the neural cells. Both types of diffusion barriers, of course, also prevent influx of metabolites from the circulation. Because neuronal function consumes vast amounts of energy and necessitates influx of diverse substrates and metabolites, tightly regulated transport systems must ensure a constant metabolite supply. Here, we review the current knowledge about transport systems that carry key metabolites, amino acids, lipids and carbohydrates into the vertebrate and Drosophila brain and how this transport is regulated. Blood-brain and hemolymph-brain transport functions are conserved and we can thus use a simple, genetically accessible model system to learn more about features and dynamics of metabolite transport into the brain.
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Affiliation(s)
- Astrid Weiler
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Anne Volkenhoff
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Helen Hertenstein
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Stefanie Schirmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany.
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34
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Ismail MAM, Mateos L, Maioli S, Merino-Serrais P, Ali Z, Lodeiro M, Westman E, Leitersdorf E, Gulyás B, Olof-Wahlund L, Winblad B, Savitcheva I, Björkhem I, Cedazo-Mínguez A. 27-Hydroxycholesterol impairs neuronal glucose uptake through an IRAP/GLUT4 system dysregulation. J Exp Med 2017; 214:699-717. [PMID: 28213512 PMCID: PMC5339669 DOI: 10.1084/jem.20160534] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/17/2016] [Accepted: 10/28/2016] [Indexed: 01/23/2023] Open
Abstract
Ismail et al. show that 27-hydroxycholesterol, a peripheral cholesterol metabolite capable of passing the blood–brain barrier, reduces brain glucose uptake by upregulating the renin-angiotensin system and inhibiting GLUT4. This alteration affects memory processes and is likely to have implications on neurodegenerative diseases. Hypercholesterolemia is associated with cognitively deteriorated states. Here, we show that excess 27-hydroxycholesterol (27-OH), a cholesterol metabolite passing from the circulation into the brain, reduced in vivo brain glucose uptake, GLUT4 expression, and spatial memory. Furthermore, patients exhibiting higher 27-OH levels had reduced 18F-fluorodeoxyglucose uptake. This interplay between 27-OH and glucose uptake revealed the engagement of the insulin-regulated aminopeptidase (IRAP). 27-OH increased the levels and activity of IRAP, countered the IRAP antagonist angiotensin IV (AngIV)–mediated glucose uptake, and enhanced the levels of the AngIV-degrading enzyme aminopeptidase N (AP-N). These effects were mediated by liver X receptors. Our results reveal a molecular link between cholesterol, brain glucose, and the brain renin-angiotensin system, all of which are affected in some neurodegenerative diseases. Thus, reducing 27-OH levels or inhibiting AP-N maybe a useful strategy in the prevention of the altered glucose metabolism and memory decline in these disorders.
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Affiliation(s)
- Muhammad-Al-Mustafa Ismail
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Laura Mateos
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Silvia Maioli
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Paula Merino-Serrais
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Zeina Ali
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, 141 86 Huddinge, Sweden
| | - Maria Lodeiro
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Eric Westman
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Eran Leitersdorf
- Center for Research, Prevention, and Treatment of Atherosclerosis, Hadassah Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Balázs Gulyás
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Lars Olof-Wahlund
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Bengt Winblad
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Irina Savitcheva
- Department of Radiology, Karolinska University Hospital, 141 86 Huddinge, Sweden
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, 141 86 Huddinge, Sweden
| | - Angel Cedazo-Mínguez
- Division of Neurogeriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet, 141 86 Stockholm, Sweden
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35
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Grote CW, Wright DE. A Role for Insulin in Diabetic Neuropathy. Front Neurosci 2016; 10:581. [PMID: 28066166 PMCID: PMC5179551 DOI: 10.3389/fnins.2016.00581] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 12/06/2016] [Indexed: 12/13/2022] Open
Abstract
The peripheral nervous system is one of several organ systems that are profoundly affected in diabetes. The longstanding view is that insulin does not have a major role in modulating neuronal function in both central and peripheral nervous systems is now being challenged. In the setting of insulin deficiency or excess insulin, it is logical to propose that insulin dysregulation can contribute to neuropathic changes in sensory neurons. This is particularly important as sensory nerve damage associated with prediabetes, type 1 and type 2 diabetes is so prevalent. Here, we discuss the current experimental literature related to insulin's role as a potential neurotrophic factor in peripheral nerve function, as well as the possibility that insulin deficiency plays a role in diabetic neuropathy. In addition, we discuss how sensory neurons in the peripheral nervous system respond to insulin similar to other insulin-sensitive tissues. Moreover, studies now suggest that sensory neurons can also become insulin resistant like other tissues. Collectively, emerging studies are revealing that insulin signaling pathways are active contributors to sensory nerve modulation, and this review highlights this novel activity and should provide new insight into insulin's role in both peripheral and central nervous system diseases.
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Affiliation(s)
- Caleb W Grote
- Department of Anatomy and Cell Biology, University of Kansas Medical Center Kansas City, KS, USA
| | - Douglas E Wright
- Department of Anatomy and Cell Biology, University of Kansas Medical Center Kansas City, KS, USA
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36
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Szablewski L. Glucose Transporters in Brain: In Health and in Alzheimer’s Disease. J Alzheimers Dis 2016; 55:1307-1320. [DOI: 10.3233/jad-160841] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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37
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Kovach CP, Al Koborssy D, Huang Z, Chelette BM, Fadool JM, Fadool DA. Mitochondrial Ultrastructure and Glucose Signaling Pathways Attributed to the Kv1.3 Ion Channel. Front Physiol 2016; 7:178. [PMID: 27242550 PMCID: PMC4871887 DOI: 10.3389/fphys.2016.00178] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/04/2016] [Indexed: 12/20/2022] Open
Abstract
Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3−∕−) results in “Super-smeller” mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3−∕− mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3−∕− male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3−∕− mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3−∕− mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very interested to understand how targeted disruption of the Kv1.3 channel in the OB can modify TEE. Our study demonstrates that Kv1.3 regulates mitochondrial structure and alters glucose utilization; two important metabolic changes that could drive whole system changes in metabolism initiated at the OB.
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Affiliation(s)
- Christopher P Kovach
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA
| | - Dolly Al Koborssy
- Program in Neuroscience, Florida State University Tallahassee, FL, USA
| | - Zhenbo Huang
- Program in Neuroscience, Florida State University Tallahassee, FL, USA
| | | | - James M Fadool
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA
| | - Debra A Fadool
- Program in Neuroscience, Florida State UniversityTallahassee, FL, USA; Department of Biological Science, Florida State UniversityTallahassee, FL, USA; Institute of Molecular Biophysics, Florida State UniversityTallahassee, FL, USA
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38
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Kojo A, Yamada K, Yamamoto T. Glucose transporter 5 (GLUT5)-like immunoreactivity is localized in subsets of neurons and glia in the rat brain. J Chem Neuroanat 2016; 74:55-70. [PMID: 27036089 DOI: 10.1016/j.jchemneu.2016.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 03/24/2016] [Accepted: 03/24/2016] [Indexed: 12/13/2022]
Abstract
This study aimed at examining the distribution of glucose transporter 5 (GLUT5), which preferentially transports fructose, in the rat brain by immunohistochemistry and Western blotting. Small immunoreactive puncta (less than 0.7μm) were sparsely distributed all over the brain, some of which appeared to be associated with microglial processes detected by an anti-ionized calcium-binding adapter molecule 1 (Iba-1) monoclonal antibody. In addition, some of these immunoreactive puncta seemed to be associated with tanycyte processes that were labeled with anti-glial fibrillary acidic protein (GFAP) monoclonal antibody. Ependymal cells were also found to be immunopositive for GLUT5. Furthermore, several noticeable GLUT5 immunoreactive profiles were observed. GLUT5 immunoreactive neurons, confirmed by double staining with neuronal nuclei (NeuN), were seen in the entopeduncular nucleus and lateral hypothalamus. Cerebellar Purkinje cells were immunopositve for GLUT5. Dense accumulation of immunoreactive puncta, some of which were neuronal elements (confirmed by immunoelectron microscopy), were observed in the optic tract and their terminal fields, namely, superior colliculus, pretectum, nucleus of the optic tract, and medial terminal nucleus of the optic tract. In addition to the associated areas of the visual system, the vestibular and cochlear nuclei also contained dense GLUT5 immunoreactive puncta. Western blot analysis of the cerebellum indicated that the antibody used recognized the 33.5 and 37.0kDa bands that were also contained in jejunum and kidney extracts. Thus, these results suggest that GLUT5 may transport fructose in subsets of the glia and neurons for an energy source of these cells.
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Affiliation(s)
- Akiko Kojo
- Division of Medical Nutrition, Faculty of Healthcare, Tokyo Healthcare University, Setagaya-ku, Tokyo 154-8568, Japan
| | - Kentaro Yamada
- Department of Oral Science, Division of Neuroscience and Brain Functions, Kanagawa Dental University, Yokosuka 238-8580, Japan
| | - Toshiharu Yamamoto
- Department of Oral Science, Division of Neuroscience and Brain Functions, Kanagawa Dental University, Yokosuka 238-8580, Japan.
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Sałat K, Gdula-Argasińska J, Malikowska N, Podkowa A, Lipkowska A, Librowski T. Effect of pregabalin on contextual memory deficits and inflammatory state-related protein expression in streptozotocin-induced diabetic mice. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:613-23. [PMID: 26984821 PMCID: PMC4866991 DOI: 10.1007/s00210-016-1230-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/07/2016] [Indexed: 01/02/2023]
Abstract
Diabetes mellitus is a metabolic disease characterized by hyperglycemia due to defects in insulin secretion or its action. Complications from long-term diabetes consist of numerous biochemical, molecular, and functional tissue alterations, including inflammation, oxidative stress, and neuropathic pain. There is also a link between diabetes mellitus and vascular dementia or Alzheimer’s disease. Hence, it is important to treat diabetic complications using drugs which do not aggravate symptoms induced by the disease itself. Pregabalin is widely used for the treatment of diabetic neuropathic pain, but little is known about its impact on cognition or inflammation-related proteins in diabetic patients. Thus, this study aimed to evaluate the effect of intraperitoneal (ip) pregabalin on contextual memory and the expression of inflammatory state-related proteins in the brains of diabetic, streptozotocin (STZ)-treated mice. STZ (200 mg/kg, ip) was used to induce diabetes mellitus. To assess the impact of pregabalin (10 mg/kg) on contextual memory, a passive avoidance task was applied. Locomotor and exploratory activities in pregabalin-treated diabetic mice were assessed by using activity cages. Using Western blot analysis, the expression of cyclooxygenase-2 (COX-2), cytosolic prostaglandin E synthase (cPGES), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), nuclear factor-ĸB (NF-ĸB) p50 and p65, aryl hydrocarbon receptor (AhR), as well as glucose transporter type-4 (GLUT4) was assessed in mouse brains after pregabalin treatment. Pregabalin did not aggravate STZ-induced learning deficits in vivo or influence animals’ locomotor activity. We observed significantly lower expression of COX-2, cPGES, and NF-κB p50 subunit, and higher expression of AhR and Nrf2 in the brains of pregabalin-treated mice in comparison to STZ-treated controls, which suggested immunomodulatory and anti-inflammatory effects of pregabalin. Antioxidant properties of pregabalin in the brains of diabetic animals were also demonstrated. Pregabalin does not potentiate STZ-induced cognitive decline, and it has antioxidant, immunomodulatory, and anti-inflammatory properties in mice. These results confirm the validity of its use in diabetic patients. Effect of pregabalin on fear-motivated memory and markers of brain tissue inflammation in diabetic mice ![]()
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Affiliation(s)
- Kinga Sałat
- Faculty of Pharmacy, Department of Pharmacodynamics, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Krakow, Poland.
| | - Joanna Gdula-Argasińska
- Faculty of Pharmacy, Department of Radioligands, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Krakow, Poland
| | - Natalia Malikowska
- Faculty of Pharmacy, Department of Pharmacodynamics, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Krakow, Poland
| | - Adrian Podkowa
- Faculty of Pharmacy, Department of Pharmacodynamics, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Krakow, Poland
| | - Anna Lipkowska
- Faculty of Pharmacy, Department of Radioligands, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Krakow, Poland
| | - Tadeusz Librowski
- Faculty of Pharmacy, Department of Radioligands, Jagiellonian University Medical College, 9 Medyczna St, 30-688, Krakow, Poland
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Ren H, Lu TY, McGraw TE, Accili D. Anorexia and impaired glucose metabolism in mice with hypothalamic ablation of Glut4 neurons. Diabetes 2015; 64:405-17. [PMID: 25187366 PMCID: PMC4303970 DOI: 10.2337/db14-0752] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The central nervous system (CNS) uses glucose independent of insulin. Nonetheless, insulin receptors and insulin-responsive glucose transporters (Glut4) often colocalize in neurons (Glut4 neurons) in anatomically and functionally distinct areas of the CNS. The apparent heterogeneity of Glut4 neurons has thus far thwarted attempts to understand their function. To answer this question, we used Cre-dependent, diphtheria toxin-mediated cell ablation to selectively remove basal hypothalamic Glut4 neurons and investigate the resulting phenotypes. After Glut4 neuron ablation, mice demonstrate altered hormone and nutrient signaling in the CNS. Accordingly, they exhibit negative energy balance phenotype characterized by reduced food intake and increased energy expenditure, without locomotor deficits or gross neuronal abnormalities. Glut4 neuron ablation affects orexigenic melanin-concentrating hormone neurons but has limited effect on neuropeptide Y/agouti-related protein and proopiomelanocortin neurons. The food intake phenotype can be partially normalized by GABA administration, suggesting that it arises from defective GABAergic transmission. Glut4 neuron-ablated mice show peripheral metabolic defects, including fasting hyperglycemia and glucose intolerance, decreased insulin levels, and elevated hepatic gluconeogenic genes. We conclude that Glut4 neurons integrate hormonal and nutritional cues and mediate CNS actions of insulin on energy balance and peripheral metabolism.
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Affiliation(s)
- Hongxia Ren
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY
| | - Taylor Y Lu
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY
| | - Timothy E McGraw
- Department of Biochemistry, Weill Cornell Medical College, New York, NY
| | - Domenico Accili
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY
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Al Koborssy D, Palouzier-Paulignan B, Salem R, Thevenet M, Romestaing C, Julliard AK. Cellular and molecular cues of glucose sensing in the rat olfactory bulb. Front Neurosci 2014; 8:333. [PMID: 25400540 PMCID: PMC4212682 DOI: 10.3389/fnins.2014.00333] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 10/03/2014] [Indexed: 11/13/2022] Open
Abstract
In the brain, glucose homeostasis of extracellular fluid is crucial to the point that systems specifically dedicated to glucose sensing are found in areas involved in energy regulation and feeding behavior. Olfaction is a major sensory modality regulating food consumption. Nutritional status in turn modulates olfactory detection. Recently it has been proposed that some olfactory bulb (OB) neurons respond to glucose similarly to hypothalamic neurons. However, the precise molecular cues governing glucose sensing in the OB are largely unknown. To decrypt these molecular mechanisms, we first used immunostaining to demonstrate a strong expression of two neuronal markers of glucose-sensitivity, insulin-dependent glucose transporter type 4 (GLUT4), and sodium glucose co-transporter type 1 (SGLT1) in specific OB layers. We showed that expression and mapping of GLUT4 but not SGLT1 were feeding state-dependent. In order to investigate the impact of metabolic status on the delivery of blood-borne glucose to the OB, we measured extracellular fluid glucose concentration using glucose biosensors simultaneously in the OB and cortex of anesthetized rats. We showed that glucose concentration in the OB is higher than in the cortex, that metabolic steady-state glucose concentration is independent of feeding state in the two brain areas, and that acute changes in glycemic conditions affect bulbar glucose concentration alone. These data provide new evidence of a direct relationship between the OB and peripheral metabolism, and emphasize the importance of glucose for the OB network, providing strong arguments toward establishing the OB as a glucose-sensing organ.
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Affiliation(s)
- Dolly Al Koborssy
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Brigitte Palouzier-Paulignan
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Rita Salem
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Marc Thevenet
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
| | - Caroline Romestaing
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés CNRS 5023, University Lyon 1, Bâtiments Darwin C and Forel Villeurbanne, France
| | - A Karyn Julliard
- Team "Olfaction: From Coding to Memory," Lyon Neuroscience Center, INSERM U1028-CNRS, University Lyon 1 Lyon, France
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Grote CW, Ryals JM, Wright DE. In vivo peripheral nervous system insulin signaling. J Peripher Nerv Syst 2014; 18:209-19. [PMID: 24028189 DOI: 10.1111/jns5.12033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 06/07/2013] [Accepted: 07/24/2013] [Indexed: 01/06/2023]
Abstract
Alterations in peripheral nervous system (PNS) insulin support may contribute to diabetic neuropathy (DN); yet, PNS insulin signaling is not fully defined. Here, we investigated in vivo insulin signaling in the PNS and compared the insulin responsiveness to that of muscle, liver, and adipose. Non-diabetic mice were administered increasing doses of insulin to define a dose-response relationship between insulin and Akt activation in the dorsal root ganglion (DRG) and sciatic nerve. Resulting EC50 doses were used to characterize the PNS insulin signaling time course and make comparisons between insulin signaling in the PNS and other peripheral tissues (i.e., muscle, liver, and adipose). The results demonstrate that the PNS is responsive to insulin and that differences in insulin signaling pathway activation exist between PNS compartments. At a therapeutically relevant dose, Akt was activated in the muscle, liver, and adipose at 30 min, correlating with the changes in blood glucose levels. Interestingly, the sciatic nerve showed a similar signaling profile as insulin-sensitive tissues; however, there was not a comparable activation in the DRG or spinal cord. These results present new evidence regarding PNS insulin signaling pathways in vivo and provide a baseline for studies investigating the contribution of disrupted PNS insulin signaling to DN pathogenesis.
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Affiliation(s)
- Caleb W Grote
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
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Jensen VFH, Bøgh IB, Lykkesfeldt J. Effect of insulin-induced hypoglycaemia on the central nervous system: evidence from experimental studies. J Neuroendocrinol 2014; 26:123-50. [PMID: 24428753 DOI: 10.1111/jne.12133] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 12/13/2013] [Accepted: 01/08/2014] [Indexed: 12/12/2022]
Abstract
Insulin-induced hypoglycaemia (IIH) is a major acute complication in type 1 as well as in type 2 diabetes, particularly during intensive insulin therapy. The brain plays a central role in the counter-regulatory response by eliciting parasympathetic and sympathetic hormone responses to restore normoglycaemia. Brain glucose concentrations, being approximately 15-20% of the blood glucose concentration in humans, are rigorously maintained during hypoglycaemia through adaptions such as increased cerebral glucose transport, decreased cerebral glucose utilisation and, possibly, by using central nervous system glycogen as a glucose reserve. However, during sustained hypoglycaemia, the brain cannot maintain a sufficient glucose influx and, as the cerebral hypoglycaemia becomes severe, electroencephalogram changes, oxidative stress and regional neuronal death ensues. With particular focus on evidence from experimental studies on nondiabetic IIH, this review outlines the central mechanisms behind the counter-regulatory response to IIH, as well as cerebral adaption to avoid sequelae of cerebral neuroglycopaenia, including seizures and coma.
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Affiliation(s)
- V F H Jensen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Diabetes Toxicology and Safety Pharmacology, Novo Nordisk A/S, Maaloev, Denmark
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Steviol glycosides modulate glucose transport in different cell types. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:348169. [PMID: 24327825 PMCID: PMC3845854 DOI: 10.1155/2013/348169] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/27/2013] [Accepted: 09/30/2013] [Indexed: 12/21/2022]
Abstract
Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.
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45
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Cura AJ, Carruthers A. Role of monosaccharide transport proteins in carbohydrate assimilation, distribution, metabolism, and homeostasis. Compr Physiol 2013; 2:863-914. [PMID: 22943001 DOI: 10.1002/cphy.c110024] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The facilitated diffusion of glucose, galactose, fructose, urate, myoinositol, and dehydroascorbicacid in mammals is catalyzed by a family of 14 monosaccharide transport proteins called GLUTs. These transporters may be divided into three classes according to sequence similarity and function/substrate specificity. GLUT1 appears to be highly expressed in glycolytically active cells and has been coopted in vitamin C auxotrophs to maintain the redox state of the blood through transport of dehydroascorbate. Several GLUTs are definitive glucose/galactose transporters, GLUT2 and GLUT5 are physiologically important fructose transporters, GLUT9 appears to be a urate transporter while GLUT13 is a proton/myoinositol cotransporter. The physiologic substrates of some GLUTs remain to be established. The GLUTs are expressed in a tissue specific manner where affinity, specificity, and capacity for substrate transport are paramount for tissue function. Although great strides have been made in characterizing GLUT-catalyzed monosaccharide transport and mapping GLUT membrane topography and determinants of substrate specificity, a unifying model for GLUT structure and function remains elusive. The GLUTs play a major role in carbohydrate homeostasis and the redistribution of sugar-derived carbons among the various organ systems. This is accomplished through a multiplicity of GLUT-dependent glucose sensing and effector mechanisms that regulate monosaccharide ingestion, absorption,distribution, cellular transport and metabolism, and recovery/retention. Glucose transport and metabolism have coevolved in mammals to support cerebral glucose utilization.
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Affiliation(s)
- Anthony J Cura
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Emmanuel Y, Cochlin LE, Tyler DJ, de Jager CA, David Smith A, Clarke K. Human hippocampal energy metabolism is impaired during cognitive activity in a lipid infusion model of insulin resistance. Brain Behav 2013; 3:134-44. [PMID: 23533158 PMCID: PMC3607154 DOI: 10.1002/brb3.124] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 11/11/2012] [Accepted: 12/23/2012] [Indexed: 11/13/2022] Open
Abstract
Neuronal glucose uptake was thought to be independent of insulin, being facilitated by glucose transporters GLUT1 and GLUT3, which do not require insulin signaling. However, it is now known that components of the insulin-mediated glucose uptake pathway, including neuronal insulin synthesis and the insulin-dependent glucose transporter GLUT4, are present in brain tissue, particularly in the hippocampus. There is considerable recent evidence that insulin signaling is crucial to optimal hippocampal function. The physiological basis, however, is not clear. We propose that while noninsulin-dependent GLUT1 and GLUT3 transport is adequate for resting needs, the surge in energy use during sustained cognitive activity requires the additional induction of insulin-signaled GLUT4 transport. We studied hippocampal high-energy phosphate metabolism in eight healthy volunteers, using a lipid infusion protocol to inhibit insulin signaling. Contrary to conventional wisdom, it is now known that free fatty acids do cross the blood-brain barrier in significant amounts. Energy metabolism within the hippocampus was assessed during standardized cognitive activity. (31)Phosphorus magnetic resonance spectroscopy was used to determine the phosphocreatine (PCr)-to-adenosine triphosphate (ATP) ratio. This ratio reflects cellular energy production in relation to concurrent cellular energy expenditure. With lipid infusion, the ratio was significantly reduced during cognitive activity (PCr/ATP 1.0 ± 0.4 compared with 1.4 ± 0.4 before infusion, P = 0.01). Without lipid infusion, there was no reduction in the ratio during cognitive activity (PCr/ATP 1.5 ± 0.3 compared with 1.4 ± 0.4, P = 0.57). This provides supporting evidence for a physiological role for insulin signaling in facilitating increased neuronal glucose uptake during sustained cognitive activity. Loss of this response, as may occur in type 2 diabetes, would lead to insufficient neuronal energy availability during cognitive activity.
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Affiliation(s)
- Yaso Emmanuel
- Cardiac Metabolism Research Group Department of Physiology, Anatomy and Genetics, University of OxfordOxford, United Kingdom
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of OxfordOxford, United Kingdom
- Oxford Project to Investigate Memory and Ageing (OPTIMA) Nuffield Department of Medicine, University of OxfordOxford, United Kingdom
| | - Lowri E Cochlin
- Cardiac Metabolism Research Group Department of Physiology, Anatomy and Genetics, University of OxfordOxford, United Kingdom
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of OxfordOxford, United Kingdom
| | - Damian J Tyler
- Cardiac Metabolism Research Group Department of Physiology, Anatomy and Genetics, University of OxfordOxford, United Kingdom
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of OxfordOxford, United Kingdom
| | - Celeste A de Jager
- Oxford Project to Investigate Memory and Ageing (OPTIMA) Nuffield Department of Medicine, University of OxfordOxford, United Kingdom
| | - A David Smith
- Oxford Project to Investigate Memory and Ageing (OPTIMA) Nuffield Department of Medicine, University of OxfordOxford, United Kingdom
| | - Kieran Clarke
- Cardiac Metabolism Research Group Department of Physiology, Anatomy and Genetics, University of OxfordOxford, United Kingdom
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Palouzier-Paulignan B, Lacroix MC, Aimé P, Baly C, Caillol M, Congar P, Julliard AK, Tucker K, Fadool DA. Olfaction under metabolic influences. Chem Senses 2012; 37:769-97. [PMID: 22832483 PMCID: PMC3529618 DOI: 10.1093/chemse/bjs059] [Citation(s) in RCA: 227] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Recently published work and emerging research efforts have suggested that the olfactory system is intimately linked with the endocrine systems that regulate or modify energy balance. Although much attention has been focused on the parallels between taste transduction and neuroendocrine controls of digestion due to the novel discovery of taste receptors and molecular components shared by the tongue and gut, the equivalent body of knowledge that has accumulated for the olfactory system, has largely been overlooked. During regular cycles of food intake or disorders of endocrine function, olfaction is modulated in response to changing levels of various molecules, such as ghrelin, orexins, neuropeptide Y, insulin, leptin, and cholecystokinin. In view of the worldwide health concern regarding the rising incidence of diabetes, obesity, and related metabolic disorders, we present a comprehensive review that addresses the current knowledge of hormonal modulation of olfactory perception and how disruption of hormonal signaling in the olfactory system can affect energy homeostasis.
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Affiliation(s)
- Brigitte Palouzier-Paulignan
- Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028/CNRS 5292, Université de Lyon150 Ave. Tony Garnier, 69366, Lyon, Cedex 07,France
- Equal contribution
| | - Marie-Christine Lacroix
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
- Equal contribution
| | - Pascaline Aimé
- Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028/CNRS 5292, Université de Lyon150 Ave. Tony Garnier, 69366, Lyon, Cedex 07,France
| | - Christine Baly
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
| | - Monique Caillol
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
| | - Patrice Congar
- INRA, UR1197 Neurobiologie de l’Olfaction et Modélisation en ImagerieF-78350, Jouy-en-JosasFrance
- IFR 144NeuroSud Paris, 91190 Gif-Sur-YvetteFrance
| | - A. Karyn Julliard
- Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028/CNRS 5292, Université de Lyon150 Ave. Tony Garnier, 69366, Lyon, Cedex 07,France
| | - Kristal Tucker
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of MedicinePittsburgh, PA 15261USAand
| | - Debra Ann Fadool
- Department of Biological Science, Programs in Neuroscience and Molecular Biophysics, The Florida State UniversityTallahassee, FL 32306-4295USA
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Pearson-Leary J, McNay EC. Intrahippocampal administration of amyloid-β(1-42) oligomers acutely impairs spatial working memory, insulin signaling, and hippocampal metabolism. J Alzheimers Dis 2012; 30:413-22. [PMID: 22430529 DOI: 10.3233/jad-2012-112192] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Increasing evidence suggests that abnormal brain accumulation of amyloid-β(1-42) (Aβ(1-42)) oligomers plays a causal role in Alzheimer's disease (AD), and in particular may cause the cognitive deficits that are the hallmark of AD. In vitro, Aβ(1-42) oligomers impair insulin signaling and suppress neural functioning. We previously showed that endogenous insulin signaling is an obligatory component of normal hippocampal function, and that disrupting this signaling led to a rapid impairment of spatial working memory, while delivery of exogenous insulin to the hippocampus enhanced both memory and metabolism; diet-induced insulin resistance both impaired spatial memory and prevented insulin from increasing metabolism or cognitive function. Hence, we tested the hypothesis that Aβ(1-42) oligomers could acutely impair hippocampal metabolic and cognitive processes in vivo in the rat. Our findings support this hypothesis: Aβ(1-42) oligomers impaired spontaneous alternation behavior while preventing the task-associated dip in hippocampal ECF glucose observed in control animals. In addition, Aβ(1-42) oligomers decreased plasma membrane translocation of the insulin-sensitive glucose transporter 4 (GluT4), and impaired insulin signaling as measured by phosphorylation of Akt. These data show in vivo that Aβ(1-42) oligomers can rapidly impair hippocampal cognitive and metabolic processes, and provide support for the hypothesis that elevated Aβ(1-42) leads to cognitive impairment via interference with hippocampal insulin signaling.
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Kumar P, Taha A, Kale RK, Cowsik SM, Baquer NZ. Physiological and biochemical effects of 17β estradiol in aging female rat brain. Exp Gerontol 2011; 46:597-605. [PMID: 21377519 DOI: 10.1016/j.exger.2011.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 01/13/2011] [Accepted: 02/22/2011] [Indexed: 01/10/2023]
Abstract
Aging in females and males is considered as the end of natural protection against age related diseases like osteoporosis, coronary heart disease, diabetes, Alzheimer's disease and Parkinson's disease. These changes increase during menopausal condition in females when the level of estradiol is decreased. The objective of this study was to observe the changes in activities of monoamine oxidase, glucose transporter-4 levels, membrane fluidity, lipid peroxidation levels and lipofuscin accumulation occurring in brains of female rats of 3 months (young), 12 months (adult) and 24 months (old) age groups, and to see whether these changes are restored to normal levels after exogenous administration of estradiol (0.1 μg/g body weight for 1 month). The results obtained in the present work revealed that normal aging was associated with significant increases in the activity of monoamine oxidase, lipid peroxidation levels and lipofuscin accumulation in the brains of aging female rats, and a decrease in glucose transporter-4 level and membrane fluidity. Our data showed that estradiol treatment significantly decreased monoamine oxidase activity, lipid peroxidation and lipofuscin accumulation in brain regions of aging rats, and a reversal of glucose transporter-4 levels and membrane fluidity was achieved, therefore it can be concluded from the present findings that estradiol's beneficial effects seemed to arise from its antilipofuscin, antioxidant and antilipidperoxidative effects, implying an overall anti-aging action. The results of this study will be useful for pharmacological modification of the aging process and applying new strategies for control of age related disorders.
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Affiliation(s)
- Pardeep Kumar
- School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India
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50
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Gómez O, Ballester-Lurbe B, Poch E, Mesonero JE, Terrado J. Developmental regulation of glucose transporters GLUT3, GLUT4 and GLUT8 in the mouse cerebellar cortex. J Anat 2010; 217:616-23. [PMID: 20819112 DOI: 10.1111/j.1469-7580.2010.01291.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Glucose uptake into the mammalian nervous system is mediated by the family of facilitative glucose transporter proteins (GLUT). In this work we investigate how the expression of the main neuronal glucose transporters (GLUT3, GLUT4 and GLUT8) is modified during cerebellar cortex maturation. Our results reveal that the levels of the three transporters increase during the postnatal development of the cerebellum. GLUT3 localizes in the growing molecular layer and in the internal granule cell layer. However, the external granule cell layer, Purkinje cell cytoplasm and cytoplasm of the other cerebellar cells lack GLUT3 expression. GLUT4 and GLUT8 have partially overlapping patterns, which are detected in the cytoplasm and dendrites of Purkinje cells, and also in the internal granule cell layer where GLUT8 displays a more diffuse pattern. The differential localization of the transporters suggests that they play different roles in the cerebellum, although GLUT4 and GLUT8 could also perform some compensatory or redundant functions. In addition, the increase in the levels and the area expressing the three transporters suggests that these roles become more important as development advances. Interestingly, the external granule cells, which have been shown to express the monocarboxylate transporter MCT2, express none of the three main neuronal GLUTs. However, when these cells migrate inwardly to differentiate in the internal granule cells, they begin to produce GLUT3, GLUT4 and GLUT8, suggesting that the maturation of the cerebellar granule cells involves a switch in their metabolism in such a way that they start using glucose as they mature.
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Affiliation(s)
- Olga Gómez
- Departamento de Medicina y Cirugía Animal, Universidad CEU-Cardenal Herrera, Moncada, Valencia, Spain
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