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Leclair E, Liggins RT, Peckett AJ, Teich T, Coy DH, Vranic M, Riddell MC. Glucagon responses to exercise-induced hypoglycaemia are improved by somatostatin receptor type 2 antagonism in a rat model of diabetes. Diabetologia 2016; 59:1724-31. [PMID: 27075449 DOI: 10.1007/s00125-016-3953-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/18/2016] [Indexed: 12/18/2022]
Abstract
AIMS/HYPOTHESIS Regular exercise is at the cornerstone of care in type 1 diabetes. However, relative hyperinsulinaemia and a blunted glucagon response to exercise promote hypoglycaemia. Recently, a selective antagonist of somatostatin receptor 2, PRL-2903, was shown to improve glucagon counterregulation to hypoglycaemia in resting streptozotocin-induced diabetic rats. The aim of this study was to test the efficacy of PRL-2903 in enhancing glucagon counterregulation during repeated hyperinsulinaemic exercise. METHODS Diabetic rats performed daily exercise for 1 week and were then exposed to saline (154 mmol/l NaCl) or PRL-2903, 10 mg/kg, before hyperinsulinaemic exercise on two separate occasions spaced 1 day apart. In the following week, animals crossed over to the alternate treatment for a third hyperinsulinaemic exercise protocol. RESULTS Liver glycogen content was lower in diabetic rats compared with control rats, despite daily insulin therapy (p < 0.05). Glucagon levels failed to increase during exercise with saline but increased three-to-six fold with PRL-2903 (all p < 0.05). Glucose concentrations tended to be higher during exercise and early recovery with PRL-2903 on both days of treatment; this difference did not achieve statistical significance (p > 0.05). CONCLUSIONS/INTERPRETATION PRL-2903 improves glucagon counterregulation during exercise. However, liver glycogen stores or other factors limit the prevention of exercise-induced hypoglycaemia in rats with streptozotocin-induced diabetes.
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Affiliation(s)
- Erwan Leclair
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada
| | | | - Ashley J Peckett
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada
| | - Trevor Teich
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada
| | - David H Coy
- Department of Medicine, Peptide Research Labs, Tulane University Medical Center, New Orleans, LA, USA
| | - Mladen Vranic
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON, Canada
| | - Michael C Riddell
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada.
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UCP2 Regulates Mitochondrial Fission and Ventromedial Nucleus Control of Glucose Responsiveness. Cell 2016; 164:872-83. [PMID: 26919426 DOI: 10.1016/j.cell.2016.02.010] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/08/2015] [Accepted: 02/03/2016] [Indexed: 01/21/2023]
Abstract
The ventromedial nucleus of the hypothalamus (VMH) plays a critical role in regulating systemic glucose homeostasis. How neurons in this brain area adapt to the changing metabolic environment to regulate circulating glucose levels is ill defined. Here, we show that glucose load results in mitochondrial fission and reduced reactive oxygen species in VMH neurons mediated by dynamin-related peptide 1 (DRP1) under the control of uncoupling protein 2 (UCP2). Probed by genetic manipulations and chemical-genetic control of VMH neuronal circuitry, we unmasked that this mitochondrial adaptation determines the size of the pool of glucose-excited neurons in the VMH and that this process regulates systemic glucose homeostasis. Thus, our data unmasked a critical cellular biological process controlled by mitochondrial dynamics in VMH regulation of systemic glucose homeostasis.
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53
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The ventromedial hypothalamus oxytocin induces locomotor behavior regulated by estrogen. Physiol Behav 2016; 164:107-12. [PMID: 27237044 DOI: 10.1016/j.physbeh.2016.05.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 01/06/2023]
Abstract
Our previous studies demonstrated that excitation of neurons in the rat ventromedial hypothalamus (VMH) induced locomotor activity. An oxytocin receptor (Oxtr) exists in the VMH and plays a role in regulating sexual behavior. However, the role of Oxtr in the VMH in locomotor activity is not clear. In this study we examined the roles of oxytocin in the VMH in running behavior, and also investigated the involvement of estrogen in this behavioral change. Microinjection of oxytocin into the VMH induced a dose-dependent increase in the running behavior in male rats. The oxytocin-induced running activity was inhibited by simultaneous injection of Oxtr-antagonist, (d(CH2)5(1), Try(Me)(2), Orn(8))-oxytocin. Oxytocin injection also induced running behavior in ovariectomized (OVX) female rats. Pretreatment of the OVX rats with estrogen augmented the oxytocin-induced running activity twofold, and increased the Oxtr mRNA in the VMH threefold. During the estrus cycle locomotor activity spontaneously increased in the dark period of proestrus. The Oxtr mRNA was up-regulated in the proestrus afternoon. Blockade of oxytocin neurotransmission by its antagonist before the onset of the dark period of proestrus decreased the following nocturnal locomotor activity. These findings demonstrate that Oxtr in the VMH is involved in the induction of running behavior and that estrogen facilitates this effect by means of Oxtr up-regulation, suggesting the involvement of oxytocin in the locomotor activity of proestrus female rats.
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54
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Rijnsburger M, Belegri E, Eggels L, Unmehopa UA, Boelen A, Serlie MJ, la Fleur SE. The effect of diet interventions on hypothalamic nutrient sensing pathways in rodents. Physiol Behav 2016; 162:61-8. [PMID: 27083123 DOI: 10.1016/j.physbeh.2016.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/25/2016] [Accepted: 04/07/2016] [Indexed: 12/13/2022]
Abstract
The hypothalamus plays a fundamental role in regulating homeostatic processes including regulation of food intake. Food intake is driven in part by energy balance, which is sensed by specific brain structures through signaling molecules such as nutrients and hormones. Both circulating glucose and fatty acids decrease food intake via a central mechanism involving the hypothalamus and brain stem. Besides playing a role in signaling energy status, glucose and fatty acids serve as fuel for neurons. This review focuses on the effects of glucose and fatty acids on hypothalamic pathways involved in regulation of energy metabolism as well as on the role of the family of peroxisome proliferator activated receptors (PPARs) which are implicated in regulation of central energy homeostasis. We further discuss the effects of different hypercaloric diets on these pathways.
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Affiliation(s)
- Merel Rijnsburger
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Evita Belegri
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Leslie Eggels
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Unga A Unmehopa
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Anita Boelen
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Mireille J Serlie
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - Susanne E la Fleur
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands.
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55
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Functional identification of a neurocircuit regulating blood glucose. Proc Natl Acad Sci U S A 2016; 113:E2073-82. [PMID: 27001850 DOI: 10.1073/pnas.1521160113] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Previous studies implicate the hypothalamic ventromedial nucleus (VMN) in glycemic control. Here, we report that selective inhibition of the subset of VMN neurons that express the transcription factor steroidogenic-factor 1 (VMN(SF1) neurons) blocks recovery from insulin-induced hypoglycemia whereas, conversely, activation of VMN(SF1) neurons causes diabetes-range hyperglycemia. Moreover, this hyperglycemic response is reproduced by selective activation of VMN(SF1) fibers projecting to the anterior bed nucleus of the stria terminalis (aBNST), but not to other brain areas innervated by VMN(SF1) neurons. We also report that neurons in the lateral parabrachial nucleus (LPBN), a brain area that is also implicated in the response to hypoglycemia, make synaptic connections with the specific subset of glucoregulatory VMN(SF1) neurons that project to the aBNST. These results collectively establish a physiological role in glucose homeostasis for VMN(SF1) neurons and suggest that these neurons are part of an ascending glucoregulatory LPBN→VMN(SF1)→aBNST neurocircuit.
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56
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Orozco-Solis R, Aguilar-Arnal L, Murakami M, Peruquetti R, Ramadori G, Coppari R, Sassone-Corsi P. The Circadian Clock in the Ventromedial Hypothalamus Controls Cyclic Energy Expenditure. Cell Metab 2016; 23:467-78. [PMID: 26959185 PMCID: PMC5373494 DOI: 10.1016/j.cmet.2016.02.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 12/07/2015] [Accepted: 02/05/2016] [Indexed: 11/21/2022]
Abstract
Organismal homeostasis relies on coherent interactions among tissues, specifically between brain-driven functions and peripheral metabolic organs. Hypothalamic circuits compute metabolic information to optimize energetic resources, but the role of the circadian clock in these pathways remains unclear. We have generated mice with targeted ablation of the core-clock gene Bmal1 within Sf1-neurons of the ventromedial hypothalamus (VMH). While this mutation does not affect the central clock in the suprachiasmatic nucleus (SCN), the VMH clock controls cyclic thermogenesis in brown adipose tissue (BAT), a tissue that governs energy balance by dissipating chemical energy as heat. VMH-driven control is exerted through increased adrenergic signaling within the sympathetic nervous system, without affecting the BAT's endogenous clock. Moreover, we show that the VMH circadian clock computes light and feeding inputs to modulate basal energy expenditure. Thus, we reveal a previously unsuspected circuit where an SCN-independent, hypothalamic circadian clock controls BAT function, energy expenditure, and thermogenesis.
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Affiliation(s)
- Ricardo Orozco-Solis
- Center for Epigenetics and Metabolism, Unite 904 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Lorena Aguilar-Arnal
- Center for Epigenetics and Metabolism, Unite 904 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Mari Murakami
- Center for Epigenetics and Metabolism, Unite 904 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Rita Peruquetti
- Center for Epigenetics and Metabolism, Unite 904 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Giorgio Ramadori
- CMU Departement Phyme, Universite de Geneve, rue Michel Servet 1, 1211 Geneva, Switzerland
| | - Roberto Coppari
- CMU Departement Phyme, Universite de Geneve, rue Michel Servet 1, 1211 Geneva, Switzerland
| | - Paolo Sassone-Corsi
- Center for Epigenetics and Metabolism, Unite 904 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA.
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Rooijackers HMM, Wiegers EC, Tack CJ, van der Graaf M, de Galan BE. Brain glucose metabolism during hypoglycemia in type 1 diabetes: insights from functional and metabolic neuroimaging studies. Cell Mol Life Sci 2016; 73:705-22. [PMID: 26521082 PMCID: PMC4735263 DOI: 10.1007/s00018-015-2079-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 10/16/2015] [Accepted: 10/20/2015] [Indexed: 12/30/2022]
Abstract
Hypoglycemia is the most frequent complication of insulin therapy in patients with type 1 diabetes. Since the brain is reliant on circulating glucose as its main source of energy, hypoglycemia poses a threat for normal brain function. Paradoxically, although hypoglycemia commonly induces immediate decline in cognitive function, long-lasting changes in brain structure and cognitive function are uncommon in patients with type 1 diabetes. In fact, recurrent hypoglycemia initiates a process of habituation that suppresses hormonal responses to and impairs awareness of subsequent hypoglycemia, which has been attributed to adaptations in the brain. These observations sparked great scientific interest into the brain's handling of glucose during (recurrent) hypoglycemia. Various neuroimaging techniques have been employed to study brain (glucose) metabolism, including PET, fMRI, MRS and ASL. This review discusses what is currently known about cerebral metabolism during hypoglycemia, and how findings obtained by functional and metabolic neuroimaging techniques contributed to this knowledge.
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Affiliation(s)
- Hanne M M Rooijackers
- Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
| | - Evita C Wiegers
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cees J Tack
- Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Marinette van der Graaf
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bastiaan E de Galan
- Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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Kamitakahara A, Xu B, Simerly R. Ventromedial hypothalamic expression of Bdnf is required to establish normal patterns of afferent GABAergic connectivity and responses to hypoglycemia. Mol Metab 2016; 5:91-101. [PMID: 26909317 PMCID: PMC4735662 DOI: 10.1016/j.molmet.2015.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 11/27/2015] [Accepted: 11/30/2015] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE The ventromedial nucleus of the hypothalamus (VMH) controls energy and glucose homeostasis through direct connections to a distributed network of nuclei in the hypothalamus, midbrain, and hindbrain. Structural changes in VMH circuit morphology have the potential to alter VMH function throughout life, however, molecular signals responsible for specifying its neural connections are not fully defined. The VMH contains a high density of neurons that express brain-derived neurotrophic factor (BDNF), a potent neurodevelopmental effector known to regulate neuronal survival, growth, differentiation, and connectivity in a number of neural systems. In the current study, we examined whether BDNF impacts the afferent and efferent connections of the VMH, as well as energy homeostatic function. METHODS To determine if BDNF is required for VMH circuit formation, a transgenic mouse model was used to conditionally delete Bdnf from steroidogenic factor 1 (SF1) expressing neurons of the VMH prior to the onset of establishing neural connections with other regions. Projections of SF1 expressing neurons were visualized with a genetically targeted fluorescent label and immunofluorescence was used to measure the density of afferents to SF1 neurons in the absence of BDNF. Physiological changes in body weight and circulating blood glucose were also evaluated in the mutant mice. RESULTS Our findings suggest that BDNF is required to establish normal densities of GABAergic afferents onto SF1 neurons located in the ventrolateral part of the VMH. Furthermore, loss of BDNF from VMH SF1 neurons results in impaired physiological responses to insulin-induced hypoglycemia. CONCLUSION The results of this study indicate that BDNF is required for formation and/or maintenance of inhibitory inputs to SF1 neurons, with enduring effects on glycemic control.
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Affiliation(s)
- Anna Kamitakahara
- Neuroscience Program, The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Richard Simerly
- Neuroscience Program, The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA.
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59
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Ghanem SS, Heinrich G, Lester SG, Pfeiffer V, Bhattacharya S, Patel PR, DeAngelis AM, Dai T, Ramakrishnan SK, Smiley ZN, Jung DY, Lee Y, Kitamura T, Ergun S, Kulkarni RN, Kim JK, Giovannucci DR, Najjar SM. Increased Glucose-induced Secretion of Glucagon-like Peptide-1 in Mice Lacking the Carcinoembryonic Antigen-related Cell Adhesion Molecule 2 (CEACAM2). J Biol Chem 2015; 291:980-8. [PMID: 26586918 DOI: 10.1074/jbc.m115.692582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Indexed: 01/11/2023] Open
Abstract
Carcinoembryonic antigen-related cell adhesion molecule 2 (CEACAM2) regulates food intake as demonstrated by hyperphagia in mice with the Ceacam2 null mutation (Cc2(-/-)). This study investigated whether CEACAM2 also regulates insulin secretion. Ceacam2 deletion caused an increase in β-cell secretory function, as assessed by hyperglycemic clamp analysis, without affecting insulin response. Although CEACAM2 is expressed in pancreatic islets predominantly in non-β-cells, basal plasma levels of insulin, glucagon and somatostatin, islet areas, and glucose-induced insulin secretion in pooled Cc2(-/-) islets were all normal. Consistent with immunofluorescence analysis showing CEACAM2 expression in distal intestinal villi, Cc2(-/-) mice exhibited a higher release of oral glucose-mediated GLP-1, an incretin that potentiates insulin secretion in response to glucose. Compared with wild type, Cc2(-/-) mice also showed a higher insulin excursion during the oral glucose tolerance test. Pretreating with exendin(9-39), a GLP-1 receptor antagonist, suppressed the effect of Ceacam2 deletion on glucose-induced insulin secretion. Moreover, GLP-1 release into the medium of GLUTag enteroendocrine cells was increased with siRNA-mediated Ceacam2 down-regulation in parallel to an increase in Ca(2+) entry through L-type voltage-dependent Ca(2+) channels. Thus, CEACAM2 regulates insulin secretion, at least in part, by a GLP-1-mediated mechanism, independent of confounding metabolic factors.
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Affiliation(s)
- Simona S Ghanem
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Garrett Heinrich
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Sumona G Lester
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Verena Pfeiffer
- the Institut für Anatomie und Zellbiologie, Universität Würzburg, D-97070 Würzburg, Germany
| | - Sumit Bhattacharya
- Neurosciences, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, Ohio 43614
| | - Payal R Patel
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Anthony M DeAngelis
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Tong Dai
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Sadeesh K Ramakrishnan
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Zachary N Smiley
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
| | - Dae Y Jung
- the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Yongjin Lee
- the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Tadahiro Kitamura
- the Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 371-8512 Gunma, Japan, and
| | - Suleyman Ergun
- the Institut für Anatomie und Zellbiologie, Universität Würzburg, D-97070 Würzburg, Germany
| | - Rohit N Kulkarni
- the Islet Cell and Regenerative Biology, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02215
| | - Jason K Kim
- the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - David R Giovannucci
- Neurosciences, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, Ohio 43614
| | - Sonia M Najjar
- From the Center for Diabetes and Endocrine Research and Departments of Physiology and Pharmacology and
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60
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Steinbusch L, Labouèbe G, Thorens B. Brain glucose sensing in homeostatic and hedonic regulation. Trends Endocrinol Metab 2015; 26:455-66. [PMID: 26163755 DOI: 10.1016/j.tem.2015.06.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 11/21/2022]
Abstract
Glucose homeostasis as well as homeostatic and hedonic control of feeding is regulated by hormonal, neuronal, and nutrient-related cues. Glucose, besides its role as a source of metabolic energy, is an important signal controlling hormone secretion and neuronal activity, hence contributing to whole-body metabolic integration in coordination with feeding control. Brain glucose sensing plays a key, but insufficiently explored, role in these metabolic and behavioral controls, which when deregulated may contribute to the development of obesity and diabetes. The recent introduction of innovative transgenic, pharmacogenetic, and optogenetic techniques allows unprecedented analysis of the complexity of central glucose sensing at the molecular, cellular, and neuronal circuit levels, which will lead to a new understanding of the pathogenesis of metabolic diseases.
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Affiliation(s)
- Laura Steinbusch
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Gwenaël Labouèbe
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Bernard Thorens
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.
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Sejling AS, Lange KHW, Frandsen CS, Diemar SS, Tarnow L, Faber J, Holst JJ, Hartmann B, Hilsted L, Kjaer TW, Juhl CB, Thorsteinsson B, Pedersen-Bjergaard U. Infrared thermographic assessment of changes in skin temperature during hypoglycaemia in patients with type 1 diabetes. Diabetologia 2015; 58:1898-906. [PMID: 25985748 DOI: 10.1007/s00125-015-3616-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 04/07/2015] [Indexed: 01/22/2023]
Abstract
AIMS/HYPOTHESIS Hypoglycaemia is associated with reduced skin temperature (Ts). We studied whether infrared thermography can detect Ts changes during hypoglycaemia in patients with type 1 diabetes and how the Ts response differs between patients with normal hypoglycaemia awareness and hypoglycaemia unawareness. METHODS Twenty-four patients with type 1 diabetes (ten aware, 14 unaware) were studied during normoglycaemia (5.0-6.0 mmol/l), hypoglycaemia (2.0-2.5 mmol/l) and during recovery from hypoglycaemia (5.0-6.0 mmol/l) using hyperinsulinaemic glucose clamping. During each 1 h phase, Ts was measured twice by infrared thermography imaging in pre-defined areas (nose, glabella and the five left fingertips), symptoms of hypoglycaemia were scored and blood was sampled. RESULTS Ts decreased during hypoglycaemia on the nose and glabella. The highest decrements were recorded on the nose (aware: -2.6 °C, unaware: -1.1 °C). In aware patients, the differences in temperature were statistically significant on both nose and glabella, whereas there was only a trend in the unaware group. There was a significant difference in hypoglycaemia-induced temperature changes between the groups. Patients in the aware group had higher hypoglycaemia symptom scores and higher adrenaline (epinephrine) levels during hypoglycaemia. CONCLUSIONS/INTERPRETATION The hypoglycaemia-associated decrement in Ts can be assessed by infrared thermography and is larger in patients with normal hypoglycaemia awareness compared with unaware patients.
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Affiliation(s)
- Anne-Sophie Sejling
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital, Dyrehavevej 29, 3400, Hillerød, Denmark,
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Abstract
Hypoglycemia caused by treatment with a sulfonylurea, a glinide, or insulin coupled with compromised defenses against the resulting falling plasma glucose concentrations is a problem for many people with diabetes. It is often recurrent, causes significant morbidity and occasional mortality, limits maintenance of euglycemia, and impairs physiological and behavioral defenses against subsequent hypoglycemia. Minimizing hypoglycemia includes acknowledging the problem; considering each risk factor; and applying the principles of intensive glycemic therapy, including drug selection and selective application of diabetes treatment technologies. For diabetes health-care providers treating most people with diabetes who are at risk for or are suffering from iatrogenic hypoglycemia, these principles include selecting appropriate individualized glycemic goals and providing structured patient education to reduce the incidence of hypoglycemia. This is typically combined with short-term scrupulous avoidance of hypoglycemia, which often will reverse impaired awareness of hypoglycemia. Clearly, the risk of hypoglycemia is modifiable.
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63
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Nessa A, Rahman SA, Hussain K. Molecular mechanisms of congenital hyperinsulinism and prospective therapeutic targets. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1064819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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64
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Sejling AS, Kjær TW, Pedersen-Bjergaard U, Diemar SS, Frandsen CSS, Hilsted L, Faber J, Holst JJ, Tarnow L, Nielsen MN, Remvig LS, Thorsteinsson B, Juhl CB. Hypoglycemia-associated changes in the electroencephalogram in patients with type 1 diabetes and normal hypoglycemia awareness or unawareness. Diabetes 2015; 64:1760-9. [PMID: 25488900 DOI: 10.2337/db14-1359] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 12/02/2014] [Indexed: 11/13/2022]
Abstract
Hypoglycemia is associated with increased activity in the low-frequency bands in the electroencephalogram (EEG). We investigated whether hypoglycemia awareness and unawareness are associated with different hypoglycemia-associated EEG changes in patients with type 1 diabetes. Twenty-four patients participated in the study: 10 with normal hypoglycemia awareness and 14 with hypoglycemia unawareness. The patients were studied at normoglycemia (5-6 mmol/L) and hypoglycemia (2.0-2.5 mmol/L), and during recovery (5-6 mmol/L) by hyperinsulinemic glucose clamp. During each 1-h period, EEG, cognitive function, and hypoglycemia symptom scores were recorded, and the counterregulatory hormonal response was measured. Quantitative EEG analysis showed that the absolute amplitude of the θ band and α-θ band up to doubled during hypoglycemia with no difference between the two groups. In the recovery period, the θ amplitude remained increased. Cognitive function declined equally during hypoglycemia in both groups and during recovery reaction time was still prolonged in a subset of tests. The aware group reported higher hypoglycemia symptom scores and had higher epinephrine and cortisol responses compared with the unaware group. In patients with type 1 diabetes, EEG changes and cognitive performance during hypoglycemia are not affected by awareness status during a single insulin-induced episode with hypoglycemia.
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Affiliation(s)
- Anne-Sophie Sejling
- Faculty of Health, University of Southern Denmark, Odense, Denmark Nordsjællands Hospital Hillerød, Hillerød, Denmark
| | - Troels W Kjær
- Roskilde Hospital, Roskilde, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Rigshospitalet, Copenhagen, Denmark
| | | | - Sarah S Diemar
- Nordsjællands Hospital Hillerød, Hillerød, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christian S S Frandsen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Hvidovre Hospital, Hvidovre, Denmark
| | | | - Jens Faber
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Herlev Hospital, Herlev, Denmark
| | - Jens J Holst
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lise Tarnow
- Nordsjællands Hospital Hillerød, Hillerød, Denmark Health, Aarhus University, Aarhus, Denmark
| | | | | | - Birger Thorsteinsson
- Nordsjællands Hospital Hillerød, Hillerød, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus B Juhl
- Faculty of Health, University of Southern Denmark, Odense, Denmark HypoSafe A/S, Lyngby, Denmark Sydvestjysk Sygehus, Esbjerg, Denmark
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LaGamma EF, Kirtok N, Chan O, Nankova BB. Partial blockade of nicotinic acetylcholine receptors improves the counterregulatory response to hypoglycemia in recurrently hypoglycemic rats. Am J Physiol Endocrinol Metab 2014; 307:E580-8. [PMID: 25117409 PMCID: PMC4250232 DOI: 10.1152/ajpendo.00237.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recurrent exposure to hypoglycemia can impair the normal counterregulatory hormonal responses that guard against hypoglycemia, leading to hypoglycemia unawareness. This pathological condition known as hypoglycemia-associated autonomic failure (HAAF) is the main adverse consequence that prevents individuals with type 1 diabetes mellitus from attaining the long-term health benefits of tight glycemic control. The underlying molecular mechanisms responsible for the progressive loss of the epinephrine response to subsequent bouts of hypoglycemia, a hallmark sign of HAAF, are largely unknown. Normally, hypoglycemia triggers both the release and biosynthesis of epinephrine through activation of nicotinic acetylcholine receptors (nAChR) on the adrenal glands. We hypothesize that excessive cholinergic stimulation may contribute to impaired counterregulation. Here, we tested whether administration of the nAChR partial agonist cytisine to reduce postganglionic synaptic activity can preserve the counterregulatory hormone responses in an animal model of HAAF. Compared with nicotine, cytisine has limited efficacy to activate nAChRs and stimulate epinephrine release and synthesis. We evaluated adrenal catecholamine production and secretion in nondiabetic rats subjected to two daily episodes of hypoglycemia for 3 days, followed by a hyperinsulinemic hypoglycemic clamp on day 4. Recurrent hypoglycemia decreased epinephrine responses, and this was associated with suppressed TH mRNA induction (a measure of adrenal catecholamine synthetic capacity). Treatment with cytisine improved glucagon responses as well as epinephrine release and production in recurrently hypoglycemic animals. These data suggest that pharmacological manipulation of ganglionic nAChRs may be promising as a translational adjunctive therapy to avoid HAAF in type 1 diabetes mellitus.
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Affiliation(s)
- Edmund F LaGamma
- Division of Newborn Medicine, Departments of Pediatrics, Biochemistry, and Molecular Biology, New York Medical College, Valhalla, New York; Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, New York; and
| | - Necla Kirtok
- Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, New York; and
| | - Owen Chan
- Department of Internal Medicine, Section of Endocrinology, Yale School of Medicine, New Haven, Connecticut
| | - Bistra B Nankova
- Division of Newborn Medicine, Departments of Pediatrics, Biochemistry, and Molecular Biology, New York Medical College, Valhalla, New York;
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Affiliation(s)
- Owen Chan
- Department of Internal Medicine-Section of Endocrinology, Yale University School of Medicine, New Haven, CT
| | - Robert S Sherwin
- Department of Internal Medicine-Section of Endocrinology, Yale University School of Medicine, New Haven, CT
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