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Mishra D, Richard JE, Maric I, Shevchouk OT, Börchers S, Eerola K, Krieger JP, Skibicka KP. Lateral parabrachial nucleus astrocytes control food intake. Front Endocrinol (Lausanne) 2024; 15:1389589. [PMID: 38887265 PMCID: PMC11180714 DOI: 10.3389/fendo.2024.1389589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 05/03/2024] [Indexed: 06/20/2024] Open
Abstract
Food intake behavior is under the tight control of the central nervous system. Most studies to date focus on the contribution of neurons to this behavior. However, although previously overlooked, astrocytes have recently been implicated to play a key role in feeding control. Most of the recent literature has focused on astrocytic contribution in the hypothalamus or the dorsal vagal complex. The contribution of astrocytes located in the lateral parabrachial nucleus (lPBN) to feeding behavior control remains poorly understood. Thus, here, we first investigated whether activation of lPBN astrocytes affects feeding behavior in male and female rats using chemogenetic activation. Astrocytic activation in the lPBN led to profound anorexia in both sexes, under both ad-libitum feeding schedule and after a fasting challenge. Astrocytes have a key contribution to glutamate homeostasis and can themselves release glutamate. Moreover, lPBN glutamate signaling is a key contributor to potent anorexia, which can be induced by lPBN activation. Thus, here, we determined whether glutamate signaling is necessary for lPBN astrocyte activation-induced anorexia, and found that pharmacological N-methyl D-aspartate (NMDA) receptor blockade attenuated the food intake reduction resulting from lPBN astrocyte activation. Since astrocytes have been shown to contribute to feeding control by modulating the feeding effect of peripheral feeding signals, we further investigated whether lPBN astrocyte activation is capable of modulating the anorexic effect of the gut/brain hormone, glucagon like peptide -1, as well as the orexigenic effect of the stomach hormone - ghrelin, and found that the feeding effect of both signals is modulated by lPBN astrocytic activation. Lastly, we found that lPBN astrocyte activation-induced anorexia is affected by a diet-induced obesity challenge, in a sex-divergent manner. Collectively, current findings uncover a novel role for lPBN astrocytes in feeding behavior control.
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Affiliation(s)
- Devesh Mishra
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Jennifer E. Richard
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Ivana Maric
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States
| | - Olesya T. Shevchouk
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Stina Börchers
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States
| | - Kim Eerola
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Jean-Philippe Krieger
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich - VetSuisse, Zurich, Switzerland
| | - Karolina P. Skibicka
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States
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Skowronski AA, Leibel RL, LeDuc CA. Neurodevelopmental Programming of Adiposity: Contributions to Obesity Risk. Endocr Rev 2024; 45:253-280. [PMID: 37971140 PMCID: PMC10911958 DOI: 10.1210/endrev/bnad031] [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: 06/07/2023] [Revised: 09/29/2023] [Accepted: 10/19/2023] [Indexed: 11/19/2023]
Abstract
This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity. The in utero and early postnatal periods represent critically sensitive developmental windows during which the hormonal and metabolic milieu affects the maturation of the hypothalamus. Maternal hyperglycemia is associated with increased transfer of glucose to the fetus driving fetal hyperinsulinemia. Elevated fetal insulin causes increased adiposity and consequently higher fetal circulating leptin concentration. Mechanistic studies in animal models indicate important roles of leptin and insulin in central and peripheral programming of adiposity, and suggest that optimal concentrations of these hormones are critical during early life. Additionally, the environmental milieu during development may be conveyed to progeny through epigenetic marks and these can potentially be vertically transmitted to subsequent generations. Thus, nutritional and metabolic/endocrine signals during perinatal development can have lifelong (and possibly multigenerational) impacts on offspring body weight regulation.
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Affiliation(s)
- Alicja A Skowronski
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Rudolph L Leibel
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Charles A LeDuc
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
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3
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Liu Z, Xiao T, Liu H. Leptin signaling and its central role in energy homeostasis. Front Neurosci 2023; 17:1238528. [PMID: 38027481 PMCID: PMC10644276 DOI: 10.3389/fnins.2023.1238528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Leptin plays a critical role in regulating appetite, energy expenditure and body weight, making it a key factor in maintaining a healthy balance. Despite numerous efforts to develop therapeutic interventions targeting leptin signaling, their effectiveness has been limited, underscoring the importance of gaining a better understanding of the mechanisms through which leptin exerts its functions. While the hypothalamus is widely recognized as the primary site responsible for the appetite-suppressing and weight-reducing effects of leptin, other brain regions have also been increasingly investigated for their involvement in mediating leptin's action. In this review, we summarize leptin signaling pathways and the neural networks that mediate the effects of leptin, with a specific emphasis on energy homeostasis.
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Affiliation(s)
- Zhaoxun Liu
- Nursing Department, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Emergency, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Tao Xiao
- Nursing Department, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hailan Liu
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
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Gogiraju R, Witzler C, Shahneh F, Hubert A, Renner L, Bochenek ML, Zifkos K, Becker C, Thati M, Schäfer K. Deletion of endothelial leptin receptors in mice promotes diet-induced obesity. Sci Rep 2023; 13:8276. [PMID: 37217565 DOI: 10.1038/s41598-023-35281-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023] Open
Abstract
Obesity promotes endothelial dysfunction. Endothelial cells not only respond, but possibly actively promote the development of obesity and metabolic dysfunction. Our aim was to characterize the role of endothelial leptin receptors (LepR) for endothelial and whole body metabolism and diet-induced obesity. Mice with tamoxifen-inducible, Tie2.Cre-ERT2-mediated deletion of LepR in endothelial cells (End.LepR knockout, KO) were fed high-fat diet (HFD) for 16 weeks. Body weight gain, serum leptin levels, visceral adiposity and adipose tissue inflammation were more pronounced in obese End.LepR-KO mice, whereas fasting serum glucose and insulin levels or the extent of hepatic steatosis did not differ. Reduced brain endothelial transcytosis of exogenous leptin, increased food intake and total energy balance were observed in End.LepR-KO mice and accompanied by brain perivascular macrophage accumulation, whereas physical activity, energy expenditure and respiratory exchange rates did not differ. Metabolic flux analysis revealed no changes in the bioenergetic profile of endothelial cells from brain or visceral adipose tissue, but higher glycolysis and mitochondrial respiration rates in those isolated from lungs. Our findings support a role for endothelial LepRs in the transport of leptin into the brain and neuronal control of food intake, and also suggest organ-specific changes in endothelial cell, but not whole-body metabolism.
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Affiliation(s)
- Rajinikanth Gogiraju
- Department of Cardiology, Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Claudius Witzler
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
| | - Fatemeh Shahneh
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
| | - Astrid Hubert
- Department of Cardiology, Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Luisa Renner
- Department of Cardiology, Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Magdalena L Bochenek
- Department of Cardiology, Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
| | - Konstantinos Zifkos
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
| | - Christian Becker
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
- Clinic of Dermatology, University Clinic Münster, Münster, Germany
| | - Madhusudhan Thati
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany
| | - Katrin Schäfer
- Department of Cardiology, Cardiology I, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
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Effect of a high-fat diet and leptin on STAT3 phosphorylation in hippocampal astrocytes. Neuroreport 2023; 34:30-37. [PMID: 36504039 DOI: 10.1097/wnr.0000000000001855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The aim of the current study was to evaluate the influence of HFD on the functionality of LepR by quantifying phosphorylated levels of 705Tyr-STAT3 in hippocampus astrocytes from mice that consumed an HFD either during the juvenile or the adult period. METHODS Five- and eight-week-old male mice, fed during 8 weeks with either control chow or HFD, received a single dose of leptin and their brains were prepared for immunofluorescence to identify double-positive GFAP/p705Tyr-STAT3 cells. RESULTS HFD intake led to increased pSTAT3 immunoreactivity in GFAP+ cells in the CA1/CA3 hippocampus areas. The effect was observed both in adolescent and adult mice. Leptin increased pSTAT3 immunoreactivity in control animals but was devoid of effect in HFD mice. HFD itself has no effect on the number of GFAP+ cells. CONCLUSIONS Our data show that regular intake of HFD enhances STAT3 signaling in CA1/CA3 astrocytes, an effect that could be linked to the increase of leptin triggered by HFD. The increase of pSTAT3 might be integral to homeostatic mechanisms aimed at maintaining hippocampus function.
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6
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Derkach KV, Sorokoumov VN, Bakhtyukov AA, Bondareva VM, Shpakov AO. Insulin and Leptin Levels in Blood and Brain Structures of Rats with Diet-Induced Obesity and the Effect of Various Drugs on Them. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022060187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Rhea EM, Banks WA, Raber J. Insulin Resistance in Peripheral Tissues and the Brain: A Tale of Two Sites. Biomedicines 2022; 10:1582. [PMID: 35884888 PMCID: PMC9312939 DOI: 10.3390/biomedicines10071582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 12/12/2022] Open
Abstract
The concept of insulin resistance has been around since a few decades after the discovery of insulin itself. To allude to the classic Charles Dicken's novel published 62 years before the discovery of insulin, in some ways, this is the best of times, as the concept of insulin resistance has expanded to include the brain, with the realization that insulin has a life beyond the regulation of glucose. In other ways, it is the worst of times as insulin resistance is implicated in devastating diseases, including diabetes mellitus, obesity, and Alzheimer's disease (AD) that affect the brain. Peripheral insulin resistance affects nearly a quarter of the United States population in adults over age 20. More recently, it has been implicated in AD, with the degree of brain insulin resistance correlating with cognitive decline. This has led to the investigation of brain or central nervous system (CNS) insulin resistance and the question of the relation between CNS and peripheral insulin resistance. While both may involve dysregulated insulin signaling, the two conditions are not identical and not always interlinked. In this review, we compare and contrast the similarities and differences between peripheral and CNS insulin resistance. We also discuss how an apolipoprotein involved in insulin signaling and related to AD, apolipoprotein E (apoE), has distinct pools in the periphery and CNS and can indirectly affect each system. As these systems are both separated but also linked via the blood-brain barrier (BBB), we discuss the role of the BBB in mediating some of the connections between insulin resistance in the brain and in the peripheral tissues.
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Affiliation(s)
- Elizabeth M. Rhea
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA 98195, USA; (E.M.R.); (W.A.B.)
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - William A. Banks
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA 98195, USA; (E.M.R.); (W.A.B.)
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
- Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR 97239, USA
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8
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LeDuc CA, Skowronski AA, Rosenbaum M. The Role of Leptin in the Development of Energy Homeostatic Systems and the Maintenance of Body Weight. Front Physiol 2021; 12:789519. [PMID: 34955895 PMCID: PMC8703217 DOI: 10.3389/fphys.2021.789519] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/17/2021] [Indexed: 12/12/2022] Open
Abstract
LEP is a pleiotropic gene and the actions of leptin extend well beyond simply acting as the signal of the size of adipose tissue stores originally proposed. This is a discussion of the multi-system interactions of leptin with the development of the neural systems regulating energy stores, and the subsequent maintenance of energy stores throughout the lifespan. The prenatal, perinatal, and later postnatal effects of leptin on systems regulating body energy stores and on the energy stores themselves are heavily influenced by the nutritional environment which leptin exposure occurs. This review discusses the prenatal and perinatal roles of leptin in establishing the neuronal circuitry and other systems relevant to the adiposity set-point (or “threshold”) and the role of leptin in maintaining weight homeostasis in adulthood. Therapeutic manipulation of the intrauterine environment, use of leptin sensitizing agents, and identification of specific cohorts who may be more responsive to leptin or other means of activating the leptin signaling pathway are ripe areas for future research.
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Affiliation(s)
- Charles A LeDuc
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, United States
| | - Alicja A Skowronski
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, United States
| | - Michael Rosenbaum
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, United States
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9
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Butiaeva LI, Slutzki T, Swick HE, Bourguignon C, Robins SC, Liu X, Storch KF, Kokoeva MV. Leptin receptor-expressing pericytes mediate access of hypothalamic feeding centers to circulating leptin. Cell Metab 2021; 33:1433-1448.e5. [PMID: 34129812 DOI: 10.1016/j.cmet.2021.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/19/2021] [Accepted: 05/21/2021] [Indexed: 12/18/2022]
Abstract
Knowledge of how leptin receptor (LepR) neurons of the mediobasal hypothalamus (MBH) access circulating leptin is still rudimentary. Employing intravital microscopy, we found that almost half of the blood-vessel-enwrapping pericytes in the MBH express LepR. Selective disruption of pericytic LepR led to increased food intake, increased fat mass, and loss of leptin-dependent signaling in nearby LepR neurons. When delivered intravenously, fluorescently tagged leptin accumulated at hypothalamic LepR pericytes, which was attenuated upon pericyte-specific LepR loss. Because a paracellular tracer was also preferentially retained at LepR pericytes, we pharmacologically targeted regulators of inter-endothelial junction tightness and found that they affect LepR neuronal signaling and food intake. Optical imaging in MBH slices revealed a long-lasting, tonic calcium increase in LepR pericytes in response to leptin, suggesting pericytic contraction and vessel constriction. Together, our data indicate that LepR pericytes facilitate localized, paracellular blood-brain barrier leaks, enabling MBH LepR neurons to access circulating leptin.
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Affiliation(s)
- Liliia I Butiaeva
- Division of Endocrinology, Department of Medicine, McGill University Health Center Research Institute, McGill University, Montreal QC H4A 3J1, Canada; Integrated Program in Neuroscience, McGill University, Montreal QC H3A 2B4, Canada
| | - Tal Slutzki
- Division of Endocrinology, Department of Medicine, McGill University Health Center Research Institute, McGill University, Montreal QC H4A 3J1, Canada; Integrated Program in Neuroscience, McGill University, Montreal QC H3A 2B4, Canada
| | - Hannah E Swick
- Division of Endocrinology, Department of Medicine, McGill University Health Center Research Institute, McGill University, Montreal QC H4A 3J1, Canada; Integrated Program in Neuroscience, McGill University, Montreal QC H3A 2B4, Canada
| | - Clément Bourguignon
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal QC H4H 1R3, Canada; Integrated Program in Neuroscience, McGill University, Montreal QC H3A 2B4, Canada
| | - Sarah C Robins
- Division of Endocrinology, Department of Medicine, McGill University Health Center Research Institute, McGill University, Montreal QC H4A 3J1, Canada
| | - Xiaohong Liu
- Division of Endocrinology, Department of Medicine, McGill University Health Center Research Institute, McGill University, Montreal QC H4A 3J1, Canada
| | - Kai-Florian Storch
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal QC H4H 1R3, Canada
| | - Maia V Kokoeva
- Division of Endocrinology, Department of Medicine, McGill University Health Center Research Institute, McGill University, Montreal QC H4A 3J1, Canada.
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10
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ADORA 1-driven brain-sympathetic neuro-adipose connections control body weight and adipose lipid metabolism. Mol Psychiatry 2021; 26:2805-2819. [PMID: 33067580 PMCID: PMC8050129 DOI: 10.1038/s41380-020-00908-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 09/14/2020] [Accepted: 10/01/2020] [Indexed: 12/21/2022]
Abstract
It is essential to elucidate brain-adipocyte interactions in order to tackle obesity and its comorbidities, as the precise control of brain-adipose tissue cross-talk is crucial for energy and glucose homeostasis. Recent studies show that in the peripheral adipose tissue, adenosine induces adipogenesis through peripheral adenosine A1 receptor (pADORA1) signaling; however, it remains unclear whether systemic and adipose tissue metabolism would also be under the control of central (c) ADORA1 signaling. Here, we use tissue-specific pharmacology and metabolic tools to clarify the roles of cADORA1 signaling in energy and adipocyte physiology. We found that cADORA1 signaling reduces body weight while also inducing adipose tissue lipolysis. cADORA1 signaling also increases adipose tissue sympathetic norepinephrine content. In contrast, pADORA1 signaling facilitates a high-fat diet-induced obesity (DIO). We propose here a novel mechanism in which cADORA1 and pADORA1 signaling hinder and aggravate DIO, respectively.
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11
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Hypothalamic Astrocytes as a Specialized and Responsive Cell Population in Obesity. Int J Mol Sci 2021; 22:ijms22126176. [PMID: 34201099 PMCID: PMC8228119 DOI: 10.3390/ijms22126176] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are a type of glial cell anatomically and functionally integrated into the neuronal regulatory circuits for the neuroendocrine control of metabolism. Being functional integral compounds of synapses, astrocytes are actively involved in the physiological regulatory aspects of metabolic control, but also in the pathological processes that link neuronal dysfunction and obesity. Between brain areas, the hypothalamus harbors specialized functional circuits that seem selectively vulnerable to metabolic damage, undergoing early cellular rearrangements which are thought to be at the core of the pathogenesis of diet-induced obesity. Such changes in the hypothalamic brain region consist of a rise in proinflammatory cytokines, the presence of a reactive phenotype in astrocytes and microglia, alterations in the cytoarchitecture and synaptology of hypothalamic circuits, and angiogenesis, a phenomenon that cannot be found elsewhere in the brain. Increasing evidence points to the direct involvement of hypothalamic astrocytes in such early metabolic disturbances, thus moving the study of these glial cells to the forefront of obesity research. Here we provide a comprehensive review of the most relevant findings of molecular and pathophysiological mechanisms by which hypothalamic astrocytes might be involved in the pathogenesis of obesity.
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12
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Guzmán-Ruiz MA, Jiménez A, Cárdenas-Rivera A, Guerrero-Vargas NN, Organista-Juárez D, Guevara-Guzmán R. Regulation of Metabolic Health by an "Olfactory-Hypothalamic Axis" and Its Possible Implications for the Development of Therapeutic Approaches for Obesity and T2D. Cell Mol Neurobiol 2021; 42:1727-1743. [PMID: 33813677 DOI: 10.1007/s10571-021-01080-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 03/12/2021] [Indexed: 12/12/2022]
Abstract
The olfactory system is responsible for the reception, integration and interpretation of odors. However, in the last years, it has been discovered that the olfactory perception of food can rapidly modulate the activity of hypothalamic neurons involved in the regulation of energy balance. Conversely, the hormonal signals derived from changes in the metabolic status of the body can also change the sensitivity of the olfactory system, suggesting that the bidirectional relationship established between the olfactory and the hypothalamic systems is key for the maintenance of metabolic homeostasis. In the first part of this review, we describe the possible mechanisms and anatomical pathways involved in the modulation of energy balance regulated by the olfactory system. Hence, we propose a model to explain its implication in the maintenance of the metabolic homeostasis of the organism. In the second part, we discuss how the olfactory system could be involved in the development of metabolic diseases such as obesity and type two diabetes and, finally, we propose the use of intranasal therapies aimed to regulate and improve the activity of the olfactory system that in turn will be able to control the neuronal activity of hypothalamic centers to prevent or ameliorate metabolic diseases.
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Affiliation(s)
- Mara Alaide Guzmán-Ruiz
- Laboratorio Sensorial, Departamento de Fisiología, Facultad de Medicina, Edificio A, 4º piso, Universidad Nacional Autónoma de México (UNAM), 04510, Ciudad de México, México.
| | - Adriana Jiménez
- Laboratorio Sensorial, Departamento de Fisiología, Facultad de Medicina, Edificio A, 4º piso, Universidad Nacional Autónoma de México (UNAM), 04510, Ciudad de México, México
| | - Alfredo Cárdenas-Rivera
- Centro de Investigación en Bioingeniería, Universidad de Ingeniería y Tecnología, Lima, Perú
| | - Natalí N Guerrero-Vargas
- Departamento de Anatomía, Facultad de Medicina, Universidad Nacional Autónoma de México, México City, México
| | - Diana Organista-Juárez
- Laboratorio Sensorial, Departamento de Fisiología, Facultad de Medicina, Edificio A, 4º piso, Universidad Nacional Autónoma de México (UNAM), 04510, Ciudad de México, México
| | - Rosalinda Guevara-Guzmán
- Laboratorio Sensorial, Departamento de Fisiología, Facultad de Medicina, Edificio A, 4º piso, Universidad Nacional Autónoma de México (UNAM), 04510, Ciudad de México, México.
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13
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Pretz D, Le Foll C, Rizwan MZ, Lutz TA, Tups A. Hyperleptinemia as a contributing factor for the impairment of glucose intolerance in obesity. FASEB J 2020; 35:e21216. [PMID: 33230896 DOI: 10.1096/fj.202001147r] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 10/20/2020] [Accepted: 11/10/2020] [Indexed: 12/21/2022]
Abstract
Obesity has emerged as a major risk factor for insulin resistance leading to the development of type 2 diabetes (T2D). The condition is characterized by high circulating levels of the adipose-derived hormone leptin and a state of chronic low-grade inflammation. Pro-inflammatory signaling in the hypothalamus is associated with a decrease of central leptin- and insulin action leading to impaired systemic glucose tolerance. Intriguingly, leptin not only regulates body weight and glucose homeostasis but also acts as a pro-inflammatory cytokine. Here we demonstrate that increasing leptin levels (62,5 µg/kg/d, PEGylated leptin) in mice fed a high-fat diet (HFD) exacerbated body weight gain and aggravated hypothalamic micro- as well as astrogliosis. In contrast, administration of a predetermined dose of a long-acting leptin antagonist (100 µg/kg/d, PESLAN) chosen to block excessive leptin signaling during diet-induced obesity (DIO) showed the opposite effect and significantly improved glucose tolerance as well as decreased the total number of microglia and astrocytes in the hypothalamus of mice fed HFD. These results suggest that high levels of leptin, such as in obesity, worsen HFD-induced micro-and astrogliosis, whereas the partial reduction of hyperleptinemia in DIO mice may have beneficial metabolic effects and improves hypothalamic gliosis.
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Affiliation(s)
- Dominik Pretz
- Centre for Neuroendocrinology, Department of Physiology, School of Medical Sciences, University of Otago, Dunedin, New Zealand.,Department of Animal Physiology, Faculty of Biology, Philipps-University Marburg, Marburg, Germany
| | - Christelle Le Foll
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland
| | - Mohammed Z Rizwan
- Centre for Neuroendocrinology, Department of Physiology, School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Thomas A Lutz
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland
| | - Alexander Tups
- Centre for Neuroendocrinology, Department of Physiology, School of Medical Sciences, University of Otago, Dunedin, New Zealand.,Department of Animal Physiology, Faculty of Biology, Philipps-University Marburg, Marburg, Germany
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14
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Pratap AA, Holsinger RMD. Altered Brain Leptin and Leptin Receptor Expression in the 5XFAD Mouse Model of Alzheimer's Disease. Pharmaceuticals (Basel) 2020; 13:E401. [PMID: 33218163 PMCID: PMC7698839 DOI: 10.3390/ph13110401] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/17/2020] [Accepted: 11/17/2020] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by the accumulation of amyloid plaques and neurofibrillary tangles. Interestingly, individuals with metabolic syndromes share some pathologies with those diagnosed with AD including neuroinflammation, insulin resistance and cognitive deficits. Leptin, an adipocyte-derived hormone, regulates metabolism, energy expenditure and satiety via its receptor, LepR. To investigate the possible involvement of leptin in AD, we examined the distribution of leptin and LepR in the brains of the 5XFAD mouse model of AD, utilizing immunofluorescent staining in young (10-12-weeks; n = 6) and old (48-52-weeks; n = 6) transgenic (Tg) mice, together with age-matched wild-type (WT) controls for both age groups (young-WT, n = 6; old-WT, n = 6). We also used double immunofluorescent staining to examine the distribution of leptin and leptin receptor expression in astrocytes. In young 5XFAD, young-WT and old-WT mice, we observed neuronal and endothelial expression of leptin and LepR throughout the brain. However, neuronal leptin and LepR expression in the old 5XFAD brain was significantly diminished. Reduced neuronal leptin and LepR expression was accompanied by plaque loading and neuroinflammation in the AD brain. A marked increase in astrocytic leptin and LepR was also observed in old 5XFAD mice compared to younger 5XFAD mice. We postulate that astrocytes may utilize LepR signalling to mediate and drive their metabolically active state when degrading amyloid in the AD brain. Overall, these findings provide evidence of impaired leptin and LepR signalling in the AD brain, supporting clinical and epidemiological studies performed in AD patients.
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Affiliation(s)
- Anishchal A. Pratap
- Brain and Mind Centre, Laboratory of Molecular Neuroscience and Dementia, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia;
- Discipline of Pathology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - R. M. Damian Holsinger
- Brain and Mind Centre, Laboratory of Molecular Neuroscience and Dementia, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia;
- Discipline of Pathology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
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15
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Robb JL, Morrissey NA, Weightman Potter PG, Smithers HE, Beall C, Ellacott KLJ. Immunometabolic Changes in Glia - A Potential Role in the Pathophysiology of Obesity and Diabetes. Neuroscience 2020; 447:167-181. [PMID: 31765625 PMCID: PMC7567742 DOI: 10.1016/j.neuroscience.2019.10.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 12/15/2022]
Abstract
Chronic low-grade inflammation is a feature of the pathophysiology of obesity and diabetes in the CNS as well as peripheral tissues. Glial cells are critical mediators of the response to inflammation in the brain. Key features of glia include their metabolic flexibility, sensitivity to changes in the CNS microenvironment, and ability to rapidly adapt their function accordingly. They are specialised cells which cooperate to promote and preserve neuronal health, playing important roles in regulating the activity of neuronal networks across the brain during different life stages. Increasing evidence points to a role of glia, most notably astrocytes and microglia, in the systemic regulation of energy and glucose homeostasis in the course of normal physiological control and during disease. Inflammation is an energetically expensive process that requires adaptive changes in cellular metabolism and, in turn, metabolic intermediates can also have immunomodulatory actions. Such "immunometabolic" changes in peripheral immune cells have been implicated in contributing to disease pathology in obesity and diabetes. This review will discuss the evidence for a role of immunometabolic changes in glial cells in the systemic regulation of energy and glucose homeostasis, and how this changes in the context of obesity and diabetes.
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Affiliation(s)
- Josephine L Robb
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Nicole A Morrissey
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Paul G Weightman Potter
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Hannah E Smithers
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Craig Beall
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Kate L J Ellacott
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK.
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16
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Specific Deletion of the Astrocyte Leptin Receptor Induces Changes in Hippocampus Glutamate Metabolism, Synaptic Transmission and Plasticity. Neuroscience 2020; 447:182-190. [DOI: 10.1016/j.neuroscience.2019.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 12/30/2022]
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17
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Barca‐Mayo O, Boender AJ, Armirotti A, De Pietri Tonelli D. Deletion of astrocytic BMAL1 results in metabolic imbalance and shorter lifespan in mice. Glia 2020; 68:1131-1147. [PMID: 31833591 PMCID: PMC7496695 DOI: 10.1002/glia.23764] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 12/19/2022]
Abstract
Disruption of the circadian cycle is strongly associated with metabolic imbalance and reduced longevity in humans. Also, rodent models of circadian arrhythmia, such as the constitutive knockout of the clock gene Bmal1, leads to metabolic disturbances and early death. Although astrocyte clock regulates molecular and behavioral circadian rhythms, its involvement in the regulation of energy balance and lifespan is unknown. Here, we show that astrocyte-specific deletion of Bmal1 is sufficient to alter energy balance, glucose homeostasis, and reduce lifespan. Mutant animals displayed impaired hypothalamic molecular clock, age-dependent astrogliosis, apoptosis of hypothalamic astrocytes, and increased glutamate and GABA levels. Importantly, modulation of GABAA-receptor signaling completely restored glutamate levels, delayed the reactive gliosis as well as the metabolic phenotypes and expanded the lifespan of the mutants. Our results demonstrate that the astrocytic clock can influence many aspects of brain function and neurological disease and suggest astrocytes and GABAA receptor as pharmacological targets to prevent the metabolic dysfunctions and shortened lifespan associated with alterations of circadian rhythms.
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Affiliation(s)
- Olga Barca‐Mayo
- Neurobiology of miRNA labFondazione Istituto Italiano di TecnologiaGenoaItaly
| | - Arjen J. Boender
- Neuromodulation of Cortical and Subcortical Circuits LabFondazione Istituto Italiano di TecnologiaGenoaItaly
| | - Andrea Armirotti
- D3 PharmaChemistryFondazione Istituto Italiano di TecnologiaGenoaItaly
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18
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Dorsal vagal complex and hypothalamic glia differentially respond to leptin and energy balance dysregulation. Transl Psychiatry 2020; 10:90. [PMID: 32152264 PMCID: PMC7062837 DOI: 10.1038/s41398-020-0767-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/18/2020] [Accepted: 02/25/2020] [Indexed: 01/16/2023] Open
Abstract
Previous studies identify a role for hypothalamic glia in energy balance regulation; however, a narrow hypothalamic focus provides an incomplete understanding of how glia throughout the brain respond to and regulate energy homeostasis. We examined the responses of glia in the dorsal vagal complex (DVC) to the adipokine leptin and high fat diet-induced obesity. DVC astrocytes functionally express the leptin receptor; in vivo pharmacological studies suggest that DVC astrocytes partly mediate the anorectic effects of leptin in lean but not diet-induced obese rats. Ex vivo calcium imaging indicated that these changes were related to a lower proportion of leptin-responsive cells in the DVC of obese versus lean animals. Finally, we investigated DVC microglia and astroglia responses to leptin and energy balance dysregulation in vivo: obesity decreased DVC astrogliosis, whereas the absence of leptin signaling in Zucker rats was associated with extensive astrogliosis in the DVC and decreased hypothalamic micro- and astrogliosis. These data uncover a novel functional heterogeneity of astrocytes in different brain nuclei of relevance to leptin signaling and energy balance regulation.
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19
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Ardid-Ruiz A, Harazin A, Barna L, Walter FR, Bladé C, Suárez M, Deli MA, Aragonès G. The effects of Vitis vinifera L. phenolic compounds on a blood-brain barrier culture model: Expression of leptin receptors and protection against cytokine-induced damage. JOURNAL OF ETHNOPHARMACOLOGY 2020; 247:112253. [PMID: 31562952 DOI: 10.1016/j.jep.2019.112253] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The medicinal properties of grapes (Vitis vinifera L.) are well known since ancient times. Ethnobotanical grape preparations, like the Ayurvedic Darakchasava are used as cardiotonic and for the treatment of cardiovascular diseases. Dried grape products are also applied in Iranian traditional medicine for memory problems, which are linked to the pathology of brain microvessels, a special part of the cardiovascular system. The anti-inflammatory and protective effects of these traditional preparations on the cardiovascular system are related to their bioactive phenolic compounds. AIM OF THE STUDY The blood-brain barrier (BBB), formed by brain capillaries, is not only involved in inflammatory and other diseases of the central nervous system, but also in many systemic diseases with an inflammatory component. Dietary obesity is a systemic chronic inflammatory condition in which the peripheral and central vascular system is affected. Among the cerebrovascular changes in obesity defective leptin transport across the BBB related to central leptin resistance is observed. Our aim was to study the protective effects of grape phenolic compounds epicatechin (EC), gallic acid (GA) and resveratrol (RSV) and grape-seed proanthocyanidin-rich extract (GSPE) on a cytokine-induced vascular endothelial inflammation model. Using a culture model of the BBB we investigated cytokine-induced endothelial damage and changes in the expression of leptin receptors and leptin transfer. MATERIALS AND METHODS For the BBB model, primary cultures of rat brain endothelial cells, glial cells and pericytes were used in co-culture. Cells were treated by tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β) (10 ng/ml each) to induce damage. Cell toxicity was evaluated by the measurement of impedance. The expression of leptin receptors was assessed by RT-qPCR and western blot. The production of reactive oxygen species (ROS) and nitric oxide (NO) were detected by fluorescent probes. RESULTS GSPE (10 μg/ml), EC (10 μM), GA (1 μM) or RSV (10 μM) did not change the viability of brain endothelial cells. The gene expression of the short leptin receptor isoform, Ob-Ra, was up-regulated by GSPE, EC and RSV, while the mRNA levels of Lrp2 and clusterin, clu/ApoJ were not affected. The tested compounds did not change the expression of the long leptin receptor isoform, Ob-Rb. RSV protected against the cytokine-induced increase in albumin permeability of the BBB model. GSPE and EC exerted an antioxidant effect and GSPE increased NO both alone and in the presence of cytokines. The cytokine-induced nuclear translocation of transcription factor NF-κB was blocked by GSPE, GA and RSV. Cytokines increased the mRNA expression of Lrp2 which was inhibited by EC. RSV increased Ob-Ra and Clu in the presence of cytokines. Cytokines elevated leptin transfer across the BBB model, which was not modified by GSPE or RSV. CONCLUSION Our results obtained on cell culture models confirm that natural grape compounds protect vascular endothelial cells against inflammatory damage in accordance with the ethnopharmacological use of grape preparations in cardiovascular diseases. Furthermore, grape compounds and GSPE, by exerting a beneficial effect on the BBB, may also be considered in the treatment of obesity after validation in clinical trials.
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Affiliation(s)
- Andrea Ardid-Ruiz
- Department of Biochemistry and Biotechnology, Nutrigenomics Research Group, Universitat Rovira I Virgili, Tarragona, Spain
| | - András Harazin
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Lilla Barna
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Fruzsina R Walter
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Cinta Bladé
- Department of Biochemistry and Biotechnology, Nutrigenomics Research Group, Universitat Rovira I Virgili, Tarragona, Spain
| | - Manuel Suárez
- Department of Biochemistry and Biotechnology, Nutrigenomics Research Group, Universitat Rovira I Virgili, Tarragona, Spain.
| | - Maria A Deli
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary; Department of Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary.
| | - Gerard Aragonès
- Department of Biochemistry and Biotechnology, Nutrigenomics Research Group, Universitat Rovira I Virgili, Tarragona, Spain
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20
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Liu X, Zheng H. Leptin-Mediated Sympathoexcitation in Obese Rats: Role for Neuron-Astrocyte Crosstalk in the Arcuate Nucleus. Front Neurosci 2019; 13:1217. [PMID: 31803004 PMCID: PMC6877670 DOI: 10.3389/fnins.2019.01217] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/28/2019] [Indexed: 11/13/2022] Open
Abstract
Introduction Accumulated evidence indicates that obesity is associated with enhanced sympathetic activation. Hypothalamic leptin-mediated signaling may contribute to the exaggerated sympathoexcitation of obesity. The goal of this study was to investigate the "neuron-astrocyte" interaction affecting leptin-mediated sympathoexcitation within the arcuate nucleus (ARCN) of the hypothalamus in obese rats. Methods and Results Obesity was induced by high-fat diet (HFD, 42% of calories from fat) in Sprague Dawley rats. Twelve weeks of HFD produced hyperleptinemia, hyperlipidemia, and insulin resistance. In anesthetized rats, microinjections of leptin into the ARCN induced increases in heart rate (HR), renal sympathetic nerve activity (RSNA), and mean arterial pressure (MAP) in both control and HFD rats. However, microinjections of leptin in HFD rats elicited higher responses of RSNA and arterial pressure than control-fed rats. It also caused the inhibition of astrocytes within the ARCN using an astrocytic metabolic inhibitor, fluorocitrate, and reduced leptin-induced sympathetic activity and blood pressure responses. Moreover, the expression of the leptin receptor in the ARCN of HFD-fed rats was significantly increased compared to rats fed a control diet. Immunohistochemistry analysis revealed leptin receptor localization from both neurons and astrocytes of the ARCN. HFD rats exhibited increased protein expression of glial fibrillary acidic protein (GFAP) in the ARCN. We also found that the expression of astrocyte-specific glutamate transporters and excitatory amino acid transporter 1 (EAAT1) and 2 (EAAT2) were decreased within the ARCN of the HFD rats. In cultured astrocytic C6 cells, 24 h of leptin treatment increased the protein expression of GFAP and reduced the expression of EAAT1 and EAAT2. Conclusion The results suggest that central leptin signaling occurs via neuron-astrocyte interactions in the ARCN and contributing to the exaggerated sympathoexcitation observed in obese rats. The effects may be mediated by the action of leptin on regulating astrocytic glutamate transporters within the ARCN of the hypothalamus.
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Affiliation(s)
- Xuefei Liu
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
| | - Hong Zheng
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
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21
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Izquierdo AG, Crujeiras AB, Casanueva FF, Carreira MC. Leptin, Obesity, and Leptin Resistance: Where Are We 25 Years Later? Nutrients 2019; 11:nu11112704. [PMID: 31717265 PMCID: PMC6893721 DOI: 10.3390/nu11112704] [Citation(s) in RCA: 243] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/27/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Leptin, a hormone that is capable of effectively reducing food intake and body weight, was initially considered for use in the treatment of obesity. However, obese subjects have since been found to have high levels of circulating leptin and to be insensitive to the exogenous administration of leptin. The inability of leptin to exert its anorexigenic effects in obese individuals, and therefore, the lack of clinical utility of leptin in obesity, is defined as leptin resistance. This phenomenon has not yet been adequately characterized. Elucidation of the molecular mechanisms underlying leptin resistance is of vital importance for the application of leptin as an effective treatment for obesity. Leptin must cross the blood–brain barrier (BBB) to reach the hypothalamus and exert its anorexigenic functions. The mechanisms involved in leptin transportation across the blood–brain barrier continue to be unclear, thereby preventing the clinical application of leptin in the treatment of obesity. In recent years, new strategies have been developed to recover the response to leptin in obesity. We have summarized these strategies in this review.
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Affiliation(s)
- Andrea G. Izquierdo
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Ana B. Crujeiras
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Felipe F. Casanueva
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Molecular Endocrinolgy, Universidad de Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| | - Marcos C. Carreira
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
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22
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Fujita Y, Yamashita T. The Effects of Leptin on Glial Cells in Neurological Diseases. Front Neurosci 2019; 13:828. [PMID: 31447640 PMCID: PMC6692660 DOI: 10.3389/fnins.2019.00828] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 07/25/2019] [Indexed: 12/11/2022] Open
Abstract
It is known that various endocrine modulators, including leptin and ghrelin, have neuroprotective roles in neurological diseases. Leptin is a hormone produced by adipocytes and was originally identified as a gene related to obesity in mice. The leptin receptors in the hypothalamus are the main target for the homeostatic regulation of body weight. Recent studies have demonstrated that leptin receptors are also expressed in other regions of the central nervous system (CNS), such as the hippocampus, cerebral cortex, and spinal cord. Accordingly, these studies identified the involvement of leptin in the regulation of neuronal survival and neural development. Furthermore, leptin has been shown to have neuroprotective functions in animal models of neurological diseases and demyelination. These observations also suggest that dysregulation of leptin signaling may be involved in the association between neurodegeneration and obesity. In this review, we summarize novel functions of leptin in animal models of neurodegenerative diseases. Specifically, we focus on the emerging evidence for the role of leptin in non-neuronal cells in the CNS, including astrocytes, microglia, and oligodendrocytes. Understanding leptin-mediated neuroprotective signals and molecular mechanisms underlying remyelination will be helpful to establish therapeutic strategies against neurological diseases.
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Affiliation(s)
- Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.,Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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23
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MacDonald AJ, Robb JL, Morrissey NA, Beall C, Ellacott KLJ. Astrocytes in neuroendocrine systems: An overview. J Neuroendocrinol 2019; 31:e12726. [PMID: 31050045 DOI: 10.1111/jne.12726] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/11/2022]
Abstract
A class of glial cell, astrocytes, is highly abundant in the central nervous system (CNS). In addition to maintaining tissue homeostasis, astrocytes regulate neuronal communication and synaptic plasticity. There is an ever-increasing appreciation that astrocytes are involved in the regulation of physiology and behaviour in normal and pathological states, including within neuroendocrine systems. Indeed, astrocytes are direct targets of hormone action in the CNS, via receptors expressed on their surface, and are also a source of regulatory neuropeptides, neurotransmitters and gliotransmitters. Furthermore, as part of the neurovascular unit, astrocytes can regulate hormone entry into the CNS. This review is intended to provide an overview of how astrocytes are impacted by and contribute to the regulation of a diverse range of neuroendocrine systems: energy homeostasis and metabolism, reproduction, fluid homeostasis, the stress response and circadian rhythms.
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Affiliation(s)
- Alastair J MacDonald
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Josephine L Robb
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Nicole A Morrissey
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Craig Beall
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Kate L J Ellacott
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
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24
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Yoo S, Cha D, Kim DW, Hoang TV, Blackshaw S. Tanycyte-Independent Control of Hypothalamic Leptin Signaling. Front Neurosci 2019; 13:240. [PMID: 30941008 PMCID: PMC6433882 DOI: 10.3389/fnins.2019.00240] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/01/2019] [Indexed: 12/29/2022] Open
Abstract
Leptin is secreted by adipocytes to regulate appetite and body weight. Recent studies have reported that tanycytes actively transport circulating leptin across the brain barrier into the hypothalamus, and are required for normal levels of hypothalamic leptin signaling. However, direct evidence for leptin receptor (LepR) expression is lacking, and the effect of tanycyte-specific deletion of LepR has not been investigated. In this study, we analyze the expression and function of the tanycytic LepR in mice. Using single-molecule fluorescent in situ hybridization (smfISH), RT-qPCR, single-cell RNA sequencing (scRNA-Seq), and selective deletion of the LepR in tanycytes, we are unable to detect expression of LepR in the tanycytes. Tanycyte-specific deletion of LepR likewise did not affect leptin-induced pSTAT3 expression in hypothalamic neurons, regardless of whether leptin was delivered by intraperitoneal or intracerebroventricular injection. Finally, we use activity-regulated scRNA-Seq (act-Seq) to comprehensively profile leptin-induced changes in gene expression in all cell types in mediobasal hypothalamus. Clear evidence for leptin signaling is only seen in endothelial cells and subsets of neurons, although virtually all cell types show leptin-induced changes in gene expression. We thus conclude that LepR expression in tanycytes is either absent or undetectably low, that tanycytes do not directly regulate hypothalamic leptin signaling through a LepR-dependent mechanism, and that leptin regulates gene expression in diverse hypothalamic cell types through both direct and indirect mechanisms.
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Affiliation(s)
- Sooyeon Yoo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - David Cha
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States.,Department of Ophthalmology, Johns Hopkins University, Baltimore, MD, United States.,Department of Neurology, Johns Hopkins University, Baltimore, MD, United States.,Center for Human Systems Biology, Johns Hopkins University, Baltimore, MD, United States.,School of Medicine, Institute for Cell Engineering, Johns Hopkins University, Baltimore, MD, United States
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25
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Derkach K, Zakharova I, Zorina I, Bakhtyukov A, Romanova I, Bayunova L, Shpakov A. The evidence of metabolic-improving effect of metformin in Ay/a mice with genetically-induced melanocortin obesity and the contribution of hypothalamic mechanisms to this effect. PLoS One 2019; 14:e0213779. [PMID: 30870482 PMCID: PMC6417728 DOI: 10.1371/journal.pone.0213779] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 02/19/2019] [Indexed: 12/16/2022] Open
Abstract
In diet-induced obesity, metformin (MF) has weight-lowering effect and improves glucose homeostasis and insulin sensitivity. However, there is no information on the efficiency of MF and the mechanisms of its action in melanocortin-type obesity. We studied the effect of the 10-day treatment with MF at the doses of 200, 400 and 600 mg/kg/day on the food intake and the metabolic and hormonal parameters in female C57Bl/6J (genotype Ay/a) agouti-mice with melanocortin-type obesity, and the influence of MF on the hypothalamic signaling in obese animals at the most effective metabolic dose (600 mg/kg/day). MF treatment led to a decrease in food intake, the body and fat weights, the plasma levels of glucose, insulin and leptin, all increased in agouti-mice, to an improvement of the lipid profile and glucose sensitivity, and to a reduced fatty liver degeneration. In the hypothalamus of obese agouti-mice, the leptin and insulin content was reduced and the expression of the genes encoding leptin receptor (LepR), MC3- and MC4-melanocortin receptors and pro-opiomelanocortin (POMC), the precursor of anorexigenic melanocortin peptides, was increased. The activities of AMP-activated kinase (AMPK) and the transcriptional factor STAT3 were increased, while Akt-kinase activity did not change from control C57Bl/6J (a/a) mice. In the hypothalamus of MF-treated agouti-mice (10 days, 600 mg/kg/day), the leptin and insulin content was restored, Akt-kinase activity was increased, and the activities of AMPK and STAT3 were reduced and did not differ from control mice. In the hypothalamus of MF-treated agouti-mice, the Pomc gene expression was six times higher than in control, while the gene expression for orexigenic neuropeptide Y was decreased by 39%. Thus, we first showed that MF treatment leads to an improvement of metabolic parameters and a decrease of hyperleptinemia and hyperinsulinaemia in genetically-induced melanocortin obesity, and the specific changes in the hypothalamic signaling makes a significant contribution to this effect of MF.
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Affiliation(s)
- Kira Derkach
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Irina Zakharova
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Inna Zorina
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Andrey Bakhtyukov
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Irina Romanova
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Liubov Bayunova
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Alexander Shpakov
- Department of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
- * E-mail:
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26
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Snow AD, Castillo GM, Nguyen BP, Choi PY, Cummings JA, Cam J, Hu Q, Lake T, Pan W, Kastin AJ, Kirschner DA, Wood SG, Rockenstein E, Masliah E, Lorimer S, Tanzi RE, Larsen L. The Amazon rain forest plant Uncaria tomentosa (cat's claw) and its specific proanthocyanidin constituents are potent inhibitors and reducers of both brain plaques and tangles. Sci Rep 2019; 9:561. [PMID: 30728442 PMCID: PMC6365538 DOI: 10.1038/s41598-019-38645-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 01/04/2019] [Indexed: 01/15/2023] Open
Abstract
Brain aging and Alzheimer's disease both demonstrate the accumulation of beta-amyloid protein containing "plaques" and tau protein containing "tangles" that contribute to accelerated memory loss and cognitive decline. In the present investigation we identified a specific plant extract and its constituents as a potential alternative natural solution for preventing and reducing both brain "plaques and tangles". PTI-00703 cat's claw (Uncaria tomentosa from a specific Peruvian source), a specific and natural plant extract from the Amazon rain forest, was identified as a potent inhibitor and reducer of both beta-amyloid fibrils (the main component of "plaques") and tau protein paired helical filaments/fibrils (the main component of "tangles"). PTI-00703 cat's claw demonstrated both the ability to prevent formation/aggregation and disaggregate preformed Aβ fibrils (1-42 and 1-40) and tau protein tangles/filaments. The disaggregation/dissolution of Aβ fibrils occurred nearly instantly when PTI-00703 cat's claw and Aβ fibrils were mixed together as shown by a variety of methods including Thioflavin T fluorometry, Congo red staining, Thioflavin S fluorescence and electron microscopy. Sophisticated structural elucidation studies identified the major fractions and specific constituents within PTI-00703 cat's claw responsible for both the observed "plaque" and "tangle" inhibitory and reducing activity. Specific proanthocyanidins (i.e. epicatechin dimers and variants thereof) are newly identified polyphenolic components within Uncaria tomentosa that possess both "plaque and tangle" reducing and inhibitory activity. One major identified specific polyphenol within PTI-00703 cat's claw was epicatechin-4β-8-epicatechin (i.e. an epicatechin dimer known as proanthocyanidin B2) that markedly reduced brain plaque load and improved short-term memory in younger and older APP "plaque-producing" (TASD-41) transgenic mice (bearing London and Swedish mutations). Proanthocyanidin B2 was also a potent inhibitor of brain inflammation as shown by reduction in astrocytosis and gliosis in TASD-41 transgenic mice. Blood-brain-barrier studies in Sprague-Dawley rats and CD-1 mice indicated that the major components of PTI-00703 cat's claw crossed the blood-brain-barrier and entered the brain parenchyma within 2 minutes of being in the blood. The discovery of a natural plant extract from the Amazon rain forest plant (i.e. Uncaria tomentosa or cat's claw) as both a potent "plaque and tangle" inhibitor and disaggregator is postulated to represent a potential breakthrough for the natural treatment of both normal brain aging and Alzheimer's disease.
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Affiliation(s)
- Alan D Snow
- Cognitive Clarity Inc., Edmonds, WA, USA.
- ProteoTech Inc., Kirkland, WA, USA.
| | | | - Beth P Nguyen
- ProteoTech Inc., Kirkland, WA, USA
- Healthcare Legacy Consulting LLC, Dallas, TX, USA
| | | | - Joel A Cummings
- Cognitive Clarity Inc., Edmonds, WA, USA
- ProteoTech Inc., Kirkland, WA, USA
| | - Judy Cam
- ProteoTech Inc., Kirkland, WA, USA
- Preclinical GPS, Washington University, St. Louis, MO, USA
| | - Qubai Hu
- ProteoTech Inc., Kirkland, WA, USA
| | - Thomas Lake
- Cognitive Clarity Inc., Edmonds, WA, USA
- ProteoTech Inc., Kirkland, WA, USA
| | - Weihong Pan
- Blood-Brain Barrier Laboratory, Pennington Biomedical Research Center at Louisiana State University, Baton Rouge, Louisiana, USA
- Biopotentials Sleep Center, Baton Rouge, LA, USA
| | - Abba J Kastin
- Blood-Brain Barrier Laboratory, Pennington Biomedical Research Center at Louisiana State University, Baton Rouge, Louisiana, USA
| | | | - Steven G Wood
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Edward Rockenstein
- Departments of Neurosciences and Pathology, University of California- San Diego, La Jolla, CA, USA
| | - Eliezer Masliah
- Departments of Neurosciences and Pathology, University of California- San Diego, La Jolla, CA, USA
- Division of Neurosciences, National Institute on Aging, Bethesda, MD, USA
| | - Stephen Lorimer
- Department of Chemistry, University of Otago, Dunedin, New Zealand
- VicLink Ltd., Wellington, New Zealand
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Lesley Larsen
- Department of Chemistry, University of Otago, Dunedin, New Zealand
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Clyburn C, Browning KN. Role of astroglia in diet-induced central neuroplasticity. J Neurophysiol 2019; 121:1195-1206. [PMID: 30699056 DOI: 10.1152/jn.00823.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Obesity, characterized by increased adiposity that develops when energy intake outweighs expenditure, is rapidly becoming a serious health crisis that affects millions of people worldwide and is associated with severe comorbid disorders including hypertension, cardiovascular disease, and type II diabetes. Obesity is also associated with the dysregulation of central neurocircuits involved in the control of autonomic, metabolic, and cognitive functions. Systemic inflammation associated with diet-induced obesity (DIO) has been proposed to be responsible for the development of these comorbidities as well as the dysregulation of central neurocircuits. A growing body of evidence suggests, however, that exposure to a high-fat diet (HFD) may cause neuroinflammation and astroglial activation even before systemic inflammation develops, which may be sufficient to cause dysregulation of central neurocircuits involved in energy homeostasis before the development of obesity. The purpose of this review is to summarize the current literature exploring astroglial-dependent modulation of central circuits following exposure to HFD and DIO, including not only dysregulation of neurocircuits involved in energy homeostasis and feeding behavior, but also the dysregulation of learning, memory, mood, and reward pathways.
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Affiliation(s)
- Courtney Clyburn
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine , Hershey, Pennsylvania
| | - Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine , Hershey, Pennsylvania
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28
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Mora-Muñoz L, Guerrero-Naranjo A, Rodríguez-Jimenez EA, Mastronardi CA, Velez-van-Meerbeke A. Leptin: role over central nervous system in epilepsy. BMC Neurosci 2018; 19:51. [PMID: 30185147 PMCID: PMC6126011 DOI: 10.1186/s12868-018-0453-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/29/2018] [Indexed: 02/05/2023] Open
Abstract
Adipose tissue is a dynamic organ with different effects on the body. Many of these effects are mediated by leptin, a hormone strongly involved in regulation of feeding and energy metabolism. It has an important role as a mediator of neuronal excitatory activity and higher brain functions. The aim of this study was to review the association between leptin and cerebral neuronal function, in particular its anticonvulsant or convulsant effects and the possible therapeutic role for treating epilepsy. For this purpose, the databases Pubmed, Science Direct, Elsevier, ResearchGate and Scielo were searched to identify experimental studies, reviews and systematic review articles, published in English, Spanish or Portuguese. Experimental studies and the presence of leptin receptors in nervous system sites other than the hypothalamus suggest an influence on higher brain functions. Indeed several animal studies have demonstrated a role of these channels in epileptiform activity as both anticonvulsive and convulsive effects have been found. The reason for these discrepancies is unclear but provides clear evidence of a potential role of leptin and leptin therapy in epileptiform activity. The association between leptin and brain function demonstrates the importance of peripheral metabolic hormones on central nervous system and opens a new way for the development of novel therapeutic interventions in diseases like epilepsy. Nevertheless further investigations are important to clarify the dynamics and diverse actions of leptin on excitatory regulation in the brain.
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Affiliation(s)
- Laura Mora-Muñoz
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Cra 24 No 63C-69, Bogotá, Colombia
| | | | | | | | - Alberto Velez-van-Meerbeke
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Cra 24 No 63C-69, Bogotá, Colombia.
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29
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Joaquim AO, Coelho CP, Motta PD, Felício LF, Bondan EF, Teodorov E, Martins MFM, Kirsten TB, Bonamin LV, Bernardi MM. Maternal food restriction in rats of the F 0 generation increases retroperitoneal fat, the number and size of adipocytes and induces periventricular astrogliosis in female F 1 and male F 2 generations. Reprod Fertil Dev 2018; 29:1340-1348. [PMID: 27239683 DOI: 10.1071/rd15309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 04/25/2016] [Indexed: 12/26/2022] Open
Abstract
The present study investigated whether male offspring (F2 generation) from female rats (F1 generation) whose mothers (F0 generation) were food restricted during gestation inherit a phenotypic transgenerational tendency towards being overweight and obese in the juvenile period, in the absence of food restriction in the F1/F2 generations. Dams of the F0 generation were 40% food restricted during pregnancy. Bodyweight, the number and size of larger and small hypodermal adipocytes (HAs), total retroperitoneal fat (RPF) weight and the expression of glial fibrillary acidic protein (GFAP) in periventricular hypothalamic astrocytes (PHAs), as determined by immunohistochemistry, were evaluated in both generations. In the female F1 generation, there was low bodyweight gain only during the juvenile period (30-65 days of age), a decrease in the size of small adipocytes, an increase in the number of small adipocytes, an increase in RPF weight and an increase in GFAP expression in PHAs at 90-95 days of age. In males of the F2 generation at 50 days of age, there was increased bodyweight and RPF weight, and a small number of adipocytes and GFAP expression in PHAs. These data indicate that the phenotypic transgenerational tendency towards being overweight and obese was observed in females (F1) from mothers (F0) that were prenatally food restricted was transmitted to their male offspring.
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Affiliation(s)
- A O Joaquim
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - C P Coelho
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - P Dias Motta
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - L F Felício
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, Av. Prof. Dr Orlando Marques de Paiva, 87, Sao Paulo, SP, 05508-270, Brazil
| | - E F Bondan
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - E Teodorov
- Mathematics, Computing and Cognition Center, Federal University of ABC, Av. dos Estados, 5001, Santo André, SP, 09210-971, Brazil
| | - M F M Martins
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - T B Kirsten
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - L V Bonamin
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
| | - M M Bernardi
- Environmental and Experimental Pathology, Paulista University, UNIP, Rua Dr Bacelar, 1212, São Paulo, SP, 04026-002, Brazil
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30
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Marina N, Turovsky E, Christie IN, Hosford PS, Hadjihambi A, Korsak A, Ang R, Mastitskaya S, Sheikhbahaei S, Theparambil SM, Gourine AV. Brain metabolic sensing and metabolic signaling at the level of an astrocyte. Glia 2018; 66:1185-1199. [PMID: 29274121 PMCID: PMC5947829 DOI: 10.1002/glia.23283] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/04/2017] [Accepted: 11/29/2017] [Indexed: 12/18/2022]
Abstract
Astrocytes support neuronal function by providing essential structural and nutritional support, neurotransmitter trafficking and recycling and may also contribute to brain information processing. In this article we review published results and report new data suggesting that astrocytes function as versatile metabolic sensors of central nervous system (CNS) milieu and play an important role in the maintenance of brain metabolic homeostasis. We discuss anatomical and functional features of astrocytes that allow them to detect and respond to changes in the brain parenchymal levels of metabolic substrates (oxygen and glucose), and metabolic waste products (carbon dioxide). We report data suggesting that astrocytes are also sensitive to circulating endocrine signals-hormones like ghrelin, glucagon-like peptide-1 and leptin, that have a major impact on the CNS mechanisms controlling food intake and energy balance. We discuss signaling mechanisms that mediate communication between astrocytes and neurons and consider how these mechanisms are recruited by astrocytes activated in response to various metabolic challenges. We review experimental data suggesting that astrocytes modulate the activities of the respiratory and autonomic neuronal networks that ensure adaptive changes in breathing and sympathetic drive in order to support the physiological and behavioral demands of the organism in ever-changing environmental conditions. Finally, we discuss evidence suggesting that altered astroglial function may contribute to the pathogenesis of disparate neurological, respiratory and cardiovascular disorders such as Rett syndrome and systemic arterial hypertension.
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Affiliation(s)
- Nephtali Marina
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
- Research Department of Metabolism and Experimental Therapeutics, Division of MedicineUniversity College LondonLondonWC1E 6JJUnited Kingdom
| | - Egor Turovsky
- Laboratory of Intracellular SignallingInstitute of Cell Biophysics, Russian Academy of SciencesPushchinoRussia
| | - Isabel N Christie
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Anna Hadjihambi
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Richard Ang
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Shahriar Sheikhbahaei
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Shefeeq M Theparambil
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Neuroscience, Physiology & PharmacologyUniversity College LondonLondonWC1E 6BTUnited Kingdom
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31
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Yasumoto Y, Miyazaki H, Ogata M, Kagawa Y, Yamamoto Y, Islam A, Yamada T, Katagiri H, Owada Y. Glial Fatty Acid-Binding Protein 7 (FABP7) Regulates Neuronal Leptin Sensitivity in the Hypothalamic Arcuate Nucleus. Mol Neurobiol 2018; 55:9016-9028. [PMID: 29623545 DOI: 10.1007/s12035-018-1033-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 03/23/2018] [Indexed: 10/17/2022]
Abstract
The hypothalamus is involved in the regulation of food intake and energy homeostasis. The arcuate nucleus (ARC) and median eminence (ME) are the primary hypothalamic sites that sense leptin and nutrients in the blood, thereby mediating food intake. Recently, studies demonstrating a role for non-neuronal cell types, including astrocytes and tanycytes, in these regulatory processes have begun to emerge. However, the molecular mechanisms involved in these activities remain largely unknown. In this study, we examined in detail the localization of fatty acid-binding protein 7 (FABP7) in the hypothalamic ARC and sought to determine its role in the hypothalamus. We performed a phenotypic analysis of diet-induced FABP7 knockout (KO) obese mice and of FABP7 KO mice treated with a single leptin injection. Immunohistochemistry revealed that FABP7+ cells are NG2+ or GFAP+ in the ARC and ME. In mice fed a high-fat diet, weight gain and food intake were lower in FABP7 KO mice than in wild-type (WT) mice. FABP7 KO mice also had lower food intake and weight gain after a single injection of leptin, and we consistently confirmed that the number of pSTAT3+ cells in the ARC indicated that the leptin-induced activation of neurons was significantly more frequent in FABP7 KO mice than in WT mice. In FABP7 KO mice-derived primary astrocyte cultures, the level of ERK phosphorylation was lower after leptin treatment. Collectively, these results indicate that in hypothalamic astrocytes, FABP7 might be involved in sensing neuronal leptin via glia-mediated mechanisms and plays a pivotal role in controlling systemic energy homeostasis.
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Affiliation(s)
- Yuki Yasumoto
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Hirofumi Miyazaki
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Masaki Ogata
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yoshiteru Kagawa
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yui Yamamoto
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Ariful Islam
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Tetsuya Yamada
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Hideki Katagiri
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Yuji Owada
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
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Inokuchi JI, Inamori KI, Kabayama K, Nagafuku M, Uemura S, Go S, Suzuki A, Ohno I, Kanoh H, Shishido F. Biology of GM3 Ganglioside. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 156:151-195. [PMID: 29747813 DOI: 10.1016/bs.pmbts.2017.10.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Since the successful molecular cloning in 1998 of GM3 synthase (GM3S, ST3GAL5), the enzyme responsible for initiating biosynthesis of all complex gangliosides, the efforts of our research group have been focused on clarifying the physiological and pathological implications of gangliosides, particularly GM3. We have identified isoforms of GM3S proteins having distinctive lengths of N-terminal cytoplasmic tails, and found that these cytoplasmic tails define subcellular localization, stability, and in vivo activity of GM3S isoforms. Our studies of the molecular pathogenesis of type 2 diabetes, focused on interaction between insulin receptor and GM3 in membrane microdomains, led to a novel concept: type 2 diabetes and certain other lifestyle-related diseases are membrane microdomain disorders resulting from aberrant expression of gangliosides. This concept has enhanced our understanding of the pathophysiological roles of GM3 and related gangliosides in various diseases involving chronic inflammation, such as insulin resistance, leptin resistance, and T-cell function and immune disorders (e.g., allergic asthma). We also demonstrated an essential role of GM3 in murine and human auditory systems; a common pathological feature of GM3S deficiency is deafness. This is the first direct link reported between gangliosides and auditory functions.
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Affiliation(s)
- Jin-Ichi Inokuchi
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan.
| | - Kei-Ichiro Inamori
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | | | - Masakazu Nagafuku
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Satoshi Uemura
- Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Shinji Go
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Akemi Suzuki
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Isao Ohno
- Center for Medical Education, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Hirotaka Kanoh
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
| | - Fumi Shishido
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan
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33
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Di Spiezio A, Sandin ES, Dore R, Müller-Fielitz H, Storck SE, Bernau M, Mier W, Oster H, Jöhren O, Pietrzik CU, Lehnert H, Schwaninger M. The LepR-mediated leptin transport across brain barriers controls food reward. Mol Metab 2018; 8:13-22. [PMID: 29254602 PMCID: PMC5985039 DOI: 10.1016/j.molmet.2017.12.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/26/2017] [Accepted: 12/02/2017] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Leptin is a key hormone in the control of appetite and body weight. Predominantly produced by white adipose tissue, it acts on the brain to inhibit homeostatic feeding and food reward. Leptin has free access to circumventricular organs, such as the median eminence, but entry into other brain centers is restricted by the blood-brain and blood-CSF barriers. So far, it is unknown for which of its central effects leptin has to penetrate brain barriers. In addition, the mechanisms mediating the transport across barriers are unclear although high expression in brain barriers suggests an important role of the leptin receptor (LepR). METHODS We selectively deleted LepR in brain endothelial and epithelial cells of mice (LepRbeKO). The expression of LepR in fenestrated vessels of the periphery and the median eminence as well as in tanycytes was not affected. RESULTS Perfusion studies showed that leptin uptake by the brain depended on LepR in brain barriers. When being fed with a rewarding high-fat diet LepRbeKO mice gained more body weight than controls. The aggravated obesity of LepRbeKO mice was due to hyperphagia and a higher sensitivity to food reward. CONCLUSIONS The LepR-mediated transport of leptin across brain barriers in endothelial cells lining microvessels and in epithelial cells of the choroid plexus controls food reward but is apparently not involved in homeostatic control of feeding.
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Affiliation(s)
- Alessandro Di Spiezio
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Elvira Sonia Sandin
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Riccardo Dore
- Department of Internal Medicine, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Helge Müller-Fielitz
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Steffen E Storck
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University of Mainz, Duesbergweg 6, 55099 Mainz, Germany
| | - Mareike Bernau
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Walter Mier
- Department of Radiochemistry, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Henrik Oster
- Institute of Neurobiology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Olaf Jöhren
- Center of Brain, Behavior and Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Claus U Pietrzik
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University of Mainz, Duesbergweg 6, 55099 Mainz, Germany
| | - Hendrik Lehnert
- Department of Internal Medicine, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany; Deutsches Zentrum für Diabetesforschung, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
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Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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Verkhratsky A, Nedergaard M. Physiology of Astroglia. Physiol Rev 2018; 98:239-389. [PMID: 29351512 PMCID: PMC6050349 DOI: 10.1152/physrev.00042.2016] [Citation(s) in RCA: 899] [Impact Index Per Article: 149.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/22/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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37
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Abstract
Obesity, a major risk factor for the development of diabetes mellitus, cardiovascular diseases and certain types of cancer, arises from a chronic positive energy balance that is often due to unlimited access to food and an increasingly sedentary lifestyle on the background of a genetic and epigenetic vulnerability. Our understanding of the humoral and neuronal systems that mediate the control of energy homeostasis has improved dramatically in the past few decades. However, our ability to develop effective strategies to slow the current epidemic of obesity has been hampered, largely owing to the limited knowledge of the mechanisms underlying resistance to the action of metabolic hormones such as leptin and ghrelin. The development of resistance to leptin and ghrelin, hormones that are crucial for the neuroendocrine control of energy homeostasis, is a hallmark of obesity. Intensive research over the past several years has yielded tremendous progress in our understanding of the cellular pathways that disrupt the action of leptin and ghrelin. In this Review, we discuss the molecular mechanisms underpinning resistance to leptin and ghrelin and how they can be exploited as targets for pharmacological management of obesity.
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Affiliation(s)
- Huxing Cui
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52246, USA
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Miguel López
- Department of Physiology, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain
- Centro de Investigación Biomédica en Red-Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52246, USA
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
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Differential hypothalamic leptin sensitivity in obese rat offspring exposed to maternal and postnatal intake of chocolate and soft drink. Nutr Diabetes 2017; 7:e242. [PMID: 28092346 PMCID: PMC5301042 DOI: 10.1038/nutd.2016.53] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/09/2016] [Accepted: 10/19/2016] [Indexed: 12/27/2022] Open
Abstract
Background/objective: Intake of high-energy foods and maternal nutrient overload increases the risk of metabolic diseases in the progeny such as obesity and diabetes. We hypothesized that maternal and postnatal intake of chocolate and soft drink will affect leptin sensitivity and hypothalamic astrocyte morphology in adult rat offspring. Methods: Pregnant Sprague-Dawley rats were fed ad libitum chow diet only (C) or with chocolate and high sucrose soft drink supplement (S). At birth, litter size was adjusted into 10 male offspring per mother. After weaning, offspring from both dietary groups were assigned to either S or C diet, giving four groups until the end of the experiment at 26 weeks of age. Results: As expected, adult offspring fed the S diet post weaning became obese (body weight: P<0.01, %body fat per kg: P<0.001) and this was due to the reduced energy expenditure (P<0.05) and hypothalamic astrogliosis (P<0.001) irrespective of maternal diet. Interesting, offspring born to S-diet-fed mothers and fed the S diet throughout postnatal life became obese despite lower energy intake than controls (P<0.05). These SS offspring showed increased feed efficiency (P<0.001) and reduced fasting pSTAT3 activity (P<0.05) in arcuate nucleus (ARC) compared with other groups. The findings indicated that the combination of the maternal and postnatal S-diet exposure induced persistent changes in leptin signalling, hence affecting energy balance. Thus, appetite regulation was more sensitive to the effect of leptin than energy expenditure, suggesting differential programming of leptin sensitivity in ARC in SS offspring. Effects of the maternal S diet were normalized when offspring were fed a chow diet after weaning. Conclusions: Maternal intake of chocolate and soft drink had long-term consequences for the metabolic phenotype in the offspring if they continued on the S diet in postnatal life. These offspring displayed obesity despite lowered energy intake associated with alterations in hypothalamic leptin signalling.
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Tsunekawa T, Banno R, Mizoguchi A, Sugiyama M, Tominaga T, Onoue T, Hagiwara D, Ito Y, Iwama S, Goto M, Suga H, Sugimura Y, Arima H. Deficiency of PTP1B Attenuates Hypothalamic Inflammation via Activation of the JAK2-STAT3 Pathway in Microglia. EBioMedicine 2017; 16:172-183. [PMID: 28094236 PMCID: PMC5474442 DOI: 10.1016/j.ebiom.2017.01.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/05/2017] [Accepted: 01/05/2017] [Indexed: 02/06/2023] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B) regulates leptin signaling in hypothalamic neurons via the JAK2-STAT3 pathway. PTP1B has also been implicated in the regulation of inflammation in the periphery. However, the role of PTP1B in hypothalamic inflammation, which is induced by a high-fat diet (HFD), remains to be elucidated. Here, we showed that STAT3 phosphorylation (p-STAT3) was increased in microglia in the hypothalamic arcuate nucleus of PTP1B knock-out mice (KO) on a HFD, accompanied by decreased Tnf and increased Il10 mRNA expression in the hypothalamus compared to wild-type mice (WT). In hypothalamic organotypic cultures, incubation with TNFα led to increased p-STAT3, accompanied by decreased Tnf and increased Il10 mRNA expression, in KO compared to WT. Incubation with p-STAT3 inhibitors or microglial depletion eliminated the differences in inflammation between genotypes. These data indicate an important role of JAK2-STAT3 signaling negatively regulated by PTP1B in microglia, which attenuates hypothalamic inflammation under HFD conditions.
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Affiliation(s)
- Taku Tsunekawa
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Ryoichi Banno
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Akira Mizoguchi
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Mariko Sugiyama
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Takashi Tominaga
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Takeshi Onoue
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Daisuke Hagiwara
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Yoshihiro Ito
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Shintaro Iwama
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya 464-8601, Japan.
| | - Motomitsu Goto
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Hidetaka Suga
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Yoshihisa Sugimura
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Hiroshi Arima
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
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Argente-Arizón P, Guerra-Cantera S, Garcia-Segura LM, Argente J, Chowen JA. Glial cells and energy balance. J Mol Endocrinol 2017; 58:R59-R71. [PMID: 27864453 DOI: 10.1530/jme-16-0182] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/18/2016] [Indexed: 12/31/2022]
Abstract
The search for new strategies and drugs to abate the current obesity epidemic has led to the intensification of research aimed at understanding the neuroendocrine control of appetite and energy expenditure. This intensified investigation of metabolic control has also included the study of how glial cells participate in this process. Glia, the most abundant cell type in the central nervous system, perform a wide spectrum of functions and are vital for the correct functioning of neurons and neuronal circuits. Current evidence indicates that hypothalamic glia, in particular astrocytes, tanycytes and microglia, are involved in both physiological and pathophysiological mechanisms of appetite and metabolic control, at least in part by regulating the signals reaching metabolic neuronal circuits. Glia transport nutrients, hormones and neurotransmitters; they secrete growth factors, hormones, cytokines and gliotransmitters and are a source of neuroprogenitor cells. These functions are regulated, as glia also respond to numerous hormones and nutrients, with the lack of specific hormonal signaling in hypothalamic astrocytes disrupting metabolic homeostasis. Here, we review some of the more recent advances in the role of glial cells in metabolic control, with a special emphasis on the differences between glial cell responses in males and females.
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Affiliation(s)
- Pilar Argente-Arizón
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
| | - Santiago Guerra-Cantera
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
| | | | - Jesús Argente
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
| | - Julie A Chowen
- Departments of Pediatrics & Pediatric EndocrinologyHospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Department of Pediatrics, Universidad Autónoma de Madrid, CIBEROBN, Instituto de Salud Carlos III, Madrid, Spain
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41
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Chen N, Sugihara H, Kim J, Fu Z, Barak B, Sur M, Feng G, Han W. Direct modulation of GFAP-expressing glia in the arcuate nucleus bi-directionally regulates feeding. eLife 2016; 5. [PMID: 27751234 PMCID: PMC5068968 DOI: 10.7554/elife.18716] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 09/17/2016] [Indexed: 12/18/2022] Open
Abstract
Multiple hypothalamic neuronal populations that regulate energy balance have been identified. Although hypothalamic glia exist in abundance and form intimate structural connections with neurons, their roles in energy homeostasis are less known. Here we show that selective Ca2+ activation of glia in the mouse arcuate nucleus (ARC) reversibly induces increased food intake while disruption of Ca2+ signaling pathway in ARC glia reduces food intake. The specific activation of ARC glia enhances the activity of agouti-related protein/neuropeptide Y (AgRP/NPY)-expressing neurons but induces no net response in pro-opiomelanocortin (POMC)-expressing neurons. ARC glial activation non-specifically depolarizes both AgRP/NPY and POMC neurons but a strong inhibitory input to POMC neurons balances the excitation. When AgRP/NPY neurons are inactivated, ARC glial activation fails to evoke any significant changes in food intake. Collectively, these results reveal an important role of ARC glia in the regulation of energy homeostasis through its interaction with distinct neuronal subtype-specific pathways.
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Affiliation(s)
- Naiyan Chen
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore.,Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Hiroki Sugihara
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Jinah Kim
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Zhanyan Fu
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Boaz Barak
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Guoping Feng
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
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42
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Chowen JA, Argente-Arizón P, Freire-Regatillo A, Frago LM, Horvath TL, Argente J. The role of astrocytes in the hypothalamic response and adaptation to metabolic signals. Prog Neurobiol 2016; 144:68-87. [PMID: 27000556 DOI: 10.1016/j.pneurobio.2016.03.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 02/09/2016] [Accepted: 03/04/2016] [Indexed: 12/19/2022]
Abstract
The hypothalamus is crucial in the regulation of homeostatic functions in mammals, with the disruption of hypothalamic circuits contributing to chronic conditions such as obesity, diabetes mellitus, hypertension, and infertility. Metabolic signals and hormonal inputs drive functional and morphological changes in the hypothalamus in attempt to maintain metabolic homeostasis. However, the dramatic increase in the incidence of obesity and its secondary complications, such as type 2 diabetes, have evidenced the need to better understand how this system functions and how it can go awry. Growing evidence points to a critical role of astrocytes in orchestrating the hypothalamic response to metabolic cues by participating in processes of synaptic transmission, synaptic plasticity and nutrient sensing. These glial cells express receptors for important metabolic signals, such as the anorexigenic hormone leptin, and determine the type and quantity of nutrients reaching their neighboring neurons. Understanding the mechanisms by which astrocytes participate in hypothalamic adaptations to changes in dietary and metabolic signals is fundamental for understanding the neuroendocrine control of metabolism and key in the search for adequate treatments of metabolic diseases.
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Affiliation(s)
- Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain.
| | - Pilar Argente-Arizón
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Alejandra Freire-Regatillo
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
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43
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Pan W. From blood to brain through BBB and astrocytic signaling. Peptides 2015; 72:121-7. [PMID: 26111490 DOI: 10.1016/j.peptides.2015.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 12/14/2022]
Abstract
In this Festschrift, I discuss the career and guiding principles to which Abba J. Kastin has adhered during the last 20 years we worked together. I briefly describe the history of our joint laboratory group, the context of studies of peptide permeation across the blood-brain barrier (BBB), and newer developments in the BBB Group as Abba steps down after serving 35 years as the founding Editor-in-Chief for Peptides. Abba's BBB studies on peptides have contributed to concepts in the neuroendocrinology of feeding and developed information on molecular trafficking across BBB cells. The astroglial leptin signaling studies and the interactions of sleep and BBB are two major directions, whereas the long-term MIF-1 project demarcates a tortuous road on translational research.
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Affiliation(s)
- Weihong Pan
- Biopotentials Sleep Center, Baton Rouge, LA 70809, USA.
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44
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Rottkamp DM, Rudenko IA, Maier MT, Roshanbin S, Yulyaningsih E, Perez L, Valdearcos M, Chua S, Koliwad SK, Xu AW. Leptin potentiates astrogenesis in the developing hypothalamus. Mol Metab 2015; 4:881-9. [PMID: 26629411 PMCID: PMC4632125 DOI: 10.1016/j.molmet.2015.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 08/18/2015] [Accepted: 08/24/2015] [Indexed: 12/05/2022] Open
Abstract
Background The proper establishment of hypothalamic feeding circuits during early development has a profound influence on energy homeostasis, and perturbing this process could predispose individuals to obesity and its associated consequences later in life. The maturation of hypothalamic neuronal circuitry in rodents takes place during the initial postnatal weeks, and this coincides with a dramatic surge in the circulating level of leptin, which is known to regulate the outgrowth of key neuronal projections in the maturing hypothalamus. Coincidently, this early postnatal period also marks the rapid proliferation and expansion of astrocytes in the brain. Methods Here we examined the effects of leptin on the proliferative capacity of astrocytes in the developing hypothalamus by treating postnatal mice with leptin. Mutant mice were also generated to conditionally remove leptin receptors from glial fibrillary acidic protein (GFAP)-expressing cells in the postnatal period. Results and conclusions We show that GFAP-expressing cells in the periventricular zone of the 3rd ventricle were responsive to leptin during the initial postnatal week. Leptin enhanced the proliferation of astrocytes in the postnatal hypothalamus and conditional removal of leptin receptors from GFAP-expressing cells during early postnatal period limited astrocyte proliferation. While increasing evidence demonstrates a direct role of leptin in regulating astrocytes in the adult brain, and given the essential function of astrocytes in modulating neuronal function and connectivity, our study indicates that leptin may exert its metabolic effects, in part, by promoting hypothalamic astrogenesis during early postnatal development. GFAP-expressing cells in the periventricular zone of 3rd ventricle are leptin-responsive during the initial postnatal week. Leptin enhances the proliferation of astrocytes in the postnatal hypothalamus. Conditional removal of leptin receptors in GFAP-expressing cells in early postnatal period reduces astrocyte proliferation.
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Affiliation(s)
- Daniele M Rottkamp
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ivan A Rudenko
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Matthew T Maier
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sahar Roshanbin
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ernie Yulyaningsih
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Luz Perez
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Martin Valdearcos
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Streamson Chua
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Suneil K Koliwad
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Allison W Xu
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
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45
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Chowen JA, Argente J. Leptin and the brain. Horm Mol Biol Clin Investig 2015; 7:351-60. [PMID: 25961273 DOI: 10.1515/hmbci.2011.113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 07/13/2011] [Indexed: 02/03/2023]
Abstract
Leptin, which comes from the Greek root leptos meaning thin, has been the focus of intense investigation since its discovery in 1994. This hormone belongs to the cytokine family and is produced by adipocytes and circulates in proportion to fat mass, thus serving as a satiety signal and informing central metabolic control centers as to the status of peripheral energy stores. However, it participates in numerous other functions both peripherally and centrally, as indicated by the wide distribution of its various receptor isoforms. Leptin is involved in brain development, most notably in development of hypothalamic centers that control metabolism, but also in other brain areas. It acts as a nutritional cue to indicate adequacy of energy stores for pubertal development and reproductive capacity. The effects of this hormone on behavior and cognition are less well studied, but it clearly is involved in specific aspects of these physiological phenomena. As obesity is a major health problem in many areas of the world, the search for pharmacological treatments to decrease appetite and increase energy expenditure is intense. Understanding the mechanisms of actions of all physiological effects of this hormone is of great interest in the pursuit of such treatment.
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46
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Role of Astrocytes in Leptin Signaling. J Mol Neurosci 2015; 56:829-839. [PMID: 25687329 DOI: 10.1007/s12031-015-0518-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 02/04/2015] [Indexed: 12/11/2022]
Abstract
To test the hypothesis that astrocytic leptin signaling induces an overall potentiation of the neuronal response to leptin, we generated a new line of astrocyte-specific leptin receptor knockout (ALKO-Δ1) mice in which no leptin receptor is expressed in astrocytes. Corresponding to cell-specific Cre recombinase expression in hypothalamic astrocytes but not neurons, this new strain of ALKO mice had attenuated pSTAT3 signaling in the arcuate nucleus of the hypothalamus 30 min after intracerebroventricular delivery of leptin. In response to high-fat diet for 2 months, the ALKO mice showed a greater increase of percent fat and blood leptin concentration. This coincided with a mild reactive gliosis in the hypothalamus. Overall, the absence of leptin receptors in astrocytes attenuated hypothalamic pSTAT3 signaling, induced a mild reactive morphology, and promoted the development of diet-induced obesity. We conclude that leptin signaling in astrocytes is essential for the homeostasis of neuroendocrine regulation in obesity.
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Argente-Arizón P, Freire-Regatillo A, Argente J, Chowen JA. Role of non-neuronal cells in body weight and appetite control. Front Endocrinol (Lausanne) 2015; 6:42. [PMID: 25859240 PMCID: PMC4374626 DOI: 10.3389/fendo.2015.00042] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/11/2015] [Indexed: 12/14/2022] Open
Abstract
The brain is composed of neurons and non-neuronal cells, with the latter encompassing glial, ependymal and endothelial cells, as well as pericytes and progenitor cells. Studies aimed at understanding how the brain operates have traditionally focused on neurons, but the importance of non-neuronal cells has become increasingly evident. Once relegated to supporting roles, it is now indubitable that these diverse cell types are fundamental for brain development and function, including that of metabolic circuits, and they may play a significant role in obesity onset and complications. They participate in processes of neurogenesis, synaptogenesis, and synaptic plasticity of metabolic circuits both during development and in adulthood. Some glial cells, such as tanycytes and astrocytes, transport circulating nutrients and metabolic factors that are fundamental for neuronal viability and activity into and within the hypothalamus. All of these cell types express receptors for a variety of metabolic factors and hormones, suggesting that they participate in metabolic function. They are the first line of defense against any assault to neurons. Indeed, microglia and astrocytes participate in the hypothalamic inflammatory response to high fat diet (HFD)-induced obesity, with this process contributing to inflammatory-related insulin and leptin resistance. Moreover, HFD-induced obesity and hyperleptinemia modify hypothalamic astroglial morphology, which is associated with changes in the synaptic inputs to neuronal metabolic circuits. Astrocytic contact with the microvasculature is increased by HFD intake and this could modify nutrient/hormonal uptake into the brain. In addition, progenitor cells in the hypothalamus are now known to have the capacity to renew metabolic circuits, and this can be affected by HFD intake and obesity. Here, we discuss our current understanding of how non-neuronal cells participate in physiological and physiopathological metabolic control.
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Affiliation(s)
- Pilar Argente-Arizón
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Fisiopatología de la Obesidad y Nutrición (CIBERobn), Centros de Investigación Biomédica en Red, Instituto de Salud Carlos III, Madrid, Spain
| | - Alejandra Freire-Regatillo
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Fisiopatología de la Obesidad y Nutrición (CIBERobn), Centros de Investigación Biomédica en Red, Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Fisiopatología de la Obesidad y Nutrición (CIBERobn), Centros de Investigación Biomédica en Red, Instituto de Salud Carlos III, Madrid, Spain
| | - Julie A. Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Fisiopatología de la Obesidad y Nutrición (CIBERobn), Centros de Investigación Biomédica en Red, Instituto de Salud Carlos III, Madrid, Spain
- *Correspondence: Julie A. Chowen, Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Avda. Menéndez Pelayo, 65, Madrid E-28009, Spain e-mail: ;
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Pan W, Kastin AJ. Can sleep apnea cause Alzheimer's disease? Neurosci Biobehav Rev 2014; 47:656-69. [DOI: 10.1016/j.neubiorev.2014.10.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/17/2014] [Accepted: 10/22/2014] [Indexed: 11/29/2022]
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He J, Kastin AJ, Wang Y, Pan W. Sleep fragmentation has differential effects on obese and lean mice. J Mol Neurosci 2014; 55:644-52. [PMID: 25152064 DOI: 10.1007/s12031-014-0403-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/13/2014] [Indexed: 12/16/2022]
Abstract
Chronic sleep fragmentation (SF), common in patients with sleep apnea, correlates with the development of obesity. We hypothesized that SF differentially affects neurobehavior in lean wild-type (WT) and obese pan-leptin receptor knockout (POKO) mice fed the same normal diet. First, we established an SF paradigm by interrupting sleep every 2 min during the inactive light span. The maneuver was effective in decreasing sleep duration and bout length, and in increasing sleep state transition and waking, without significant rebound sleep in the dark span. Changes of sleep architecture were evident in the light span and consistent across days 1-10 of SF. There was reduced NREM, shortened sleep latency, and increased state transitions. During the light span of the first day of SF, there also was reduction of REM and increased delta power of slow-wave sleep. Potential effects of SF on thermal pain threshold, locomotor activity, and anxiety were then tested. POKO mice had a lower circadian amplitude of pain latency than WT mice in the hot plate test, and both groups had lowest tolerance at 4 pm (zeitgeber time (ZT) 10) and longest latency at 4 am (ZT 22). SF increased the pain threshold in WT but not in POKO mice when tested at 8 a.m. (ZT 2). Both the POKO mutation and SF resulted in reduced physical activity and increased anxiety, but there was no additive effect of these two factors. Overall, SF and the POKO mutation differentially regulate mouse behavior. The results suggest that obesity can blunt neurobehavioral responses to SF.
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Affiliation(s)
- Junyun He
- Blood Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA
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Ouyang S, Hsuchou H, Kastin AJ, Mishra PK, Wang Y, Pan W. Leukocyte infiltration into spinal cord of EAE mice is attenuated by removal of endothelial leptin signaling. Brain Behav Immun 2014; 40:61-73. [PMID: 24576482 PMCID: PMC4131983 DOI: 10.1016/j.bbi.2014.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 02/04/2014] [Accepted: 02/06/2014] [Indexed: 01/17/2023] Open
Abstract
Leptin, a pleiotropic adipokine, crosses the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) from the periphery and facilitates experimental autoimmune encephalomyelitis (EAE). EAE induces dynamic changes of leptin receptors in enriched brain and spinal cord microvessels, leading to further questions about the potential roles of endothelial leptin signaling in EAE progression. In endothelial leptin receptor specific knockout (ELKO) mice, there were lower EAE behavioral scores in the early phase of the disorder, better preserved BSCB function shown by reduced uptake of sodium fluorescein and leukocyte infiltration into the spinal cord. Flow cytometry showed that the ELKO mutation decreased the number of CD3 and CD45 cells in the spinal cord, although immune cell profiles in peripheral organs were unchanged. Not only were CD4(+) and CD8(+) T lymphocytes reduced, there were also lower numbers of CD11b(+)Gr1(+) granulocytes in the spinal cord of ELKO mice. In enriched microvessels from the spinal cord of the ELKO mice, the decreased expression of mRNAs for a few tight junction proteins was less pronounced in ELKO than WT mice, as was the elevation of mRNA for CCL5, CXCL9, IFN-γ, and TNF-α. Altogether, ELKO mice show reduced inflammation at the level of the BSCB, less leukocyte infiltration, and better preserved tight junction protein expression and BBB function than WT mice after EAE. Although leptin concentrations were high in ELKO mice and microvascular leptin receptors show an initial elevation before inhibition during the course of EAE, removal of leptin signaling helped to reduce disease burden. We conclude that endothelial leptin signaling exacerbates BBB dysfunction to worsen EAE.
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Affiliation(s)
- Suidong Ouyang
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Hung Hsuchou
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Abba J Kastin
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Pramod K Mishra
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Yuping Wang
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Weihong Pan
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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