1
|
Harvey T, Rios M. The Role of BDNF and TrkB in the Central Control of Energy and Glucose Balance: An Update. Biomolecules 2024; 14:424. [PMID: 38672441 PMCID: PMC11048226 DOI: 10.3390/biom14040424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/27/2024] [Accepted: 03/29/2024] [Indexed: 04/28/2024] Open
Abstract
The global rise in obesity and related health issues, such as type 2 diabetes and cardiovascular disease, is alarming. Gaining a deeper insight into the central neural pathways and mechanisms that regulate energy and glucose homeostasis is crucial for developing effective interventions to combat this debilitating condition. A significant body of evidence from studies in humans and rodents indicates that brain-derived neurotrophic factor (BDNF) signaling plays a key role in regulating feeding, energy expenditure, and glycemic control. BDNF is a highly conserved neurotrophin that signals via the tropomyosin-related kinase B (TrkB) receptor to facilitate neuronal survival, differentiation, and synaptic plasticity and function. Recent studies have shed light on the mechanisms through which BDNF influences energy and glucose balance. This review will cover our current understanding of the brain regions, neural circuits, and cellular and molecular mechanisms underlying the metabolic actions of BDNF and TrkB.
Collapse
Affiliation(s)
- Theresa Harvey
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA;
| | - Maribel Rios
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA;
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| |
Collapse
|
2
|
Anekwe CV, Ahn YJ, Bajaj SS, Stanford FC. Pharmacotherapy causing weight gain and metabolic alteration in those with obesity and obesity-related conditions: A review. Ann N Y Acad Sci 2024; 1533:145-155. [PMID: 38385953 PMCID: PMC11057385 DOI: 10.1111/nyas.15112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
This review aims to summarize pharmacological interventions that may affect adiposity and metabolic equilibrium in individuals with obesity. Pharmacological therapy is frequently used to treat medical conditions that are both directly related to obesity (such as hypertension and type 2 diabetes) and indirectly related to obesity (such as asthma, insomnia, and type 1 diabetes). This pharmacological therapy may result in weight gain and alterations in the metabolic profile. Many medication classes are implicated in the pharmacologic causes of weight gain, including antipsychotics, glucocorticoids, beta-adrenergic blockers, tricyclic antidepressants, antihistamines, insulin, neuropathic agents, sleep agents, and steroids. This article describes the mechanisms of action and pathways of pharmacological interventions causing obesity.
Collapse
Affiliation(s)
- Chika V. Anekwe
- Massachusetts General Hospital, MGH Weight Center, Department of Internal Medicine-Division of Endocrinology-Metabolism Unit, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Yoon Ji Ahn
- Massachusetts General Hospital, MGH Weight Center, Department of Internal Medicine-Division of Endocrinology-Metabolism Unit, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | | | - Fatima Cody Stanford
- Harvard Medical School, Boston, MA, USA
- Massachusetts General Hospital, MGH Weight Center, Department of Internal Medicine-Division of Endocrinology-Neuroendocrine Unit and Department of Pediatrics-Division of Pediatric Endocrinology, Nutrition Obesity Research Center at Harvard (NORCH), Boston, MA, USA
| |
Collapse
|
3
|
Chu P, Guo W, You H, Lu B. Regulation of Satiety by Bdnf-e2-Expressing Neurons through TrkB Activation in Ventromedial Hypothalamus. Biomolecules 2023; 13:biom13050822. [PMID: 37238691 DOI: 10.3390/biom13050822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 04/23/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
The transcripts for Bdnf (brain-derived neurotrophic factor), driven by different promoters, are expressed in different brain regions to control different body functions. Specific promoter(s) that regulates energy balance remain unclear. We show that disruption of Bdnf promoters I and II but not IV and VI in mice (Bdnf-e1-/-, Bdnf-e2-/-) results in obesity. Whereas Bdnf-e1-/- exhibited impaired thermogenesis, Bdnf-e2-/- showed hyperphagia and reduced satiety before the onset of obesity. The Bdnf-e2 transcripts were primarily expressed in ventromedial hypothalamus (VMH), a nucleus known to regulate satiety. Re-expressing Bdnf-e2 transcript in VMH or chemogenetic activation of VMH neurons rescued the hyperphagia and obesity of Bdnf-e2-/- mice. Deletion of BDNF receptor TrkB in VMH neurons in wildtype mice resulted in hyperphagia and obesity, and infusion of TrkB agonistic antibody into VMH of Bdnf-e2-/- mice alleviated these phenotypes. Thus, Bdnf-e2-transcripts in VMH neurons play a key role in regulating energy intake and satiety through TrkB pathway.
Collapse
Affiliation(s)
- Pengcheng Chu
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Guo
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - He You
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bai Lu
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
- Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Centre, 10 Marais Street, Stellenbosch 7600, South Africa
| |
Collapse
|
4
|
Tuluc P, Theiner T, Jacobo-Piqueras N, Geisler SM. Role of High Voltage-Gated Ca 2+ Channel Subunits in Pancreatic β-Cell Insulin Release. From Structure to Function. Cells 2021; 10:2004. [PMID: 34440773 PMCID: PMC8393260 DOI: 10.3390/cells10082004] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/27/2021] [Accepted: 08/03/2021] [Indexed: 02/07/2023] Open
Abstract
The pancreatic islets of Langerhans secrete several hormones critical for glucose homeostasis. The β-cells, the major cellular component of the pancreatic islets, secrete insulin, the only hormone capable of lowering the plasma glucose concentration. The counter-regulatory hormone glucagon is secreted by the α-cells while δ-cells secrete somatostatin that via paracrine mechanisms regulates the α- and β-cell activity. These three peptide hormones are packed into secretory granules that are released through exocytosis following a local increase in intracellular Ca2+ concentration. The high voltage-gated Ca2+ channels (HVCCs) occupy a central role in pancreatic hormone release both as a source of Ca2+ required for excitation-secretion coupling as well as a scaffold for the release machinery. HVCCs are multi-protein complexes composed of the main pore-forming transmembrane α1 and the auxiliary intracellular β, extracellular α2δ, and transmembrane γ subunits. Here, we review the current understanding regarding the role of all HVCC subunits expressed in pancreatic β-cell on electrical activity, excitation-secretion coupling, and β-cell mass. The evidence we review was obtained from many seminal studies employing pharmacological approaches as well as genetically modified mouse models. The significance for diabetes in humans is discussed in the context of genetic variations in the genes encoding for the HVCC subunits.
Collapse
Affiliation(s)
- Petronel Tuluc
- Centre for Molecular Biosciences, Department of Pharmacology and Toxicology, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; (T.T.); (N.J.-P.); (S.M.G.)
| | | | | | | |
Collapse
|
5
|
Fagan MP, Ameroso D, Meng A, Rock A, Maguire J, Rios M. Essential and sex-specific effects of mGluR5 in ventromedial hypothalamus regulating estrogen signaling and glucose balance. Proc Natl Acad Sci U S A 2020; 117:19566-19577. [PMID: 32719118 PMCID: PMC7430975 DOI: 10.1073/pnas.2011228117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The ventromedial hypothalamus (VMH) plays chief roles regulating energy and glucose homeostasis and is sexually dimorphic. We discovered that expression of metabotropic glutamate receptor subtype 5 (mGluR5) in the VMH is regulated by caloric status in normal mice and reduced in brain-derived neurotrophic factor (BDNF) mutants, which are severely obese and have diminished glucose balance control. These findings led us to investigate whether mGluR5 might act downstream of BDNF to critically regulate VMH neuronal activity and metabolic function. We found that mGluR5 depletion in VMH SF1 neurons did not affect energy balance regulation. However, it significantly impaired insulin sensitivity, glycemic control, lipid metabolism, and sympathetic output in females but not in males. These sex-specific deficits are linked to reductions in intrinsic excitability and firing rate of SF1 neurons. Abnormal excitatory and inhibitory synapse assembly and elevated expression of the GABAergic synthetic enzyme GAD67 also cooperate to decrease and potentiate the synaptic excitatory and inhibitory tone onto mutant SF1 neurons, respectively. Notably, these alterations arise from disrupted functional interactions of mGluR5 with estrogen receptors that switch the normally positive effects of estrogen on SF1 neuronal activity and glucose balance control to paradoxical and detrimental. The collective data inform an essential central mechanism regulating metabolic function in females and underlying the protective effects of estrogen against metabolic disease.
Collapse
Affiliation(s)
- Micaella P Fagan
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
| | - Dominique Ameroso
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
| | - Alice Meng
- Graduate Program in Cell, Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
| | - Anna Rock
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111
| | - Jamie Maguire
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111
| | - Maribel Rios
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111;
- Graduate Program in Cell, Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111
| |
Collapse
|
6
|
Ablinger C, Geisler SM, Stanika RI, Klein CT, Obermair GJ. Neuronal α 2δ proteins and brain disorders. Pflugers Arch 2020; 472:845-863. [PMID: 32607809 PMCID: PMC7351808 DOI: 10.1007/s00424-020-02420-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/08/2020] [Accepted: 06/12/2020] [Indexed: 01/31/2023]
Abstract
α2δ proteins are membrane-anchored extracellular glycoproteins which are abundantly expressed in the brain and the peripheral nervous system. They serve as regulatory subunits of voltage-gated calcium channels and, particularly in nerve cells, regulate presynaptic and postsynaptic functions independently from their role as channel subunits. α2δ proteins are the targets of the widely prescribed anti-epileptic and anti-allodynic drugs gabapentin and pregabalin, particularly for the treatment of neuropathic pain conditions. Recently, the human genes (CACNA2D1-4) encoding for the four known α2δ proteins (isoforms α2δ-1 to α2δ-4) have been linked to a large variety of neurological and neuropsychiatric disorders including epilepsy, autism spectrum disorders, bipolar disorders, schizophrenia, and depressive disorders. Here, we provide an overview of the hitherto identified disease associations of all known α2δ genes, hypothesize on the pathophysiological mechanisms considering their known physiological roles, and discuss the most immanent future research questions. Elucidating their specific physiological and pathophysiological mechanisms may open the way for developing entirely novel therapeutic paradigms for treating brain disorders.
Collapse
Affiliation(s)
- Cornelia Ablinger
- Institute of Physiology, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Stefanie M Geisler
- Department of Pharmacology and Toxicology, University of Innsbruck, 6020, Innsbruck, Austria
| | - Ruslan I Stanika
- Division Physiology, Karl Landsteiner University of Health Sciences, 3500, Krems, Austria
| | - Christian T Klein
- Department of Life Sciences, IMC University of Applied Sciences, 3500, Krems, Austria
| | - Gerald J Obermair
- Institute of Physiology, Medical University Innsbruck, 6020, Innsbruck, Austria.
- Division Physiology, Karl Landsteiner University of Health Sciences, 3500, Krems, Austria.
| |
Collapse
|
7
|
Felsted JA, Meng A, Ameroso D, Rios M. Sex-specific Effects of α2δ-1 in the Ventromedial Hypothalamus of Female Mice Controlling Glucose and Lipid Balance. Endocrinology 2020; 161:5825490. [PMID: 32337532 PMCID: PMC7286619 DOI: 10.1210/endocr/bqaa068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/21/2020] [Indexed: 01/22/2023]
Abstract
The thrombospondin receptor alpha2delta-1 (α2δ-1) plays essential roles promoting the activity of SF1 neurons in the ventromedial hypothalamus (VMH) and mediating glucose and lipid metabolism in male mice. Its role in the VMH of female mice remains to be defined, especially considering that this hypothalamic region is sexually dimorphic. We found that α2δ-1 depletion in SF1 neurons differentially affects glucose and lipid balance control and sympathetic tone in females compared to males. Mutant females show a modest increase in relative body weight gain when fed a high-fat diet (HFD) and normal energy expenditure, indicating that α2δ-1 is not a critical regulator of energy balance in females, similar to males. However, diminished α2δ-1 function in the VMH leads to enhanced glycemic control in females fed a chow diet, in contrast to the glucose intolerance reported previously in mutant males. Interestingly, the effects of α2δ-1 on glucose balance in females are influenced by diet. Accordingly, females but not males lacking α2δ-1 exhibit diminished glycemic control as well as susceptibility to hepatic steatosis when fed a HFD. Increased hepatic sympathetic tone and CD36 mRNA expression and reduced adiponectin levels underlie these diet-induced metabolic alterations in mutant females. The results indicate that α2δ-1 in VMH SF1 neurons critically regulates metabolic function through sexually dimorphic mechanisms. These findings are clinically relevant since metabolic alterations have been reported as a side effect in human patients prescribed gabapentinoid drugs, known to inhibit α2δ-1 function, for the treatment of seizure disorders, neuropathic pain, and anxiety disorders.
Collapse
Affiliation(s)
- Jennifer A Felsted
- Graduate Program in Biochemical and Molecular Nutrition, Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts
| | - Alice Meng
- Graduate Program in Cell Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts
| | - Dominique Ameroso
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts
| | - Maribel Rios
- Graduate Program in Cell Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts
- Correspondence: Maribel Rios, PhD, 136 Harrison Avenue, Boston, MA 02111. E-mail:
| |
Collapse
|
8
|
Bikbaev A, Ciuraszkiewicz-Wojciech A, Heck J, Klatt O, Freund R, Mitlöhner J, Enrile Lacalle S, Sun M, Repetto D, Frischknecht R, Ablinger C, Rohlmann A, Missler M, Obermair GJ, Di Biase V, Heine M. Auxiliary α2δ1 and α2δ3 Subunits of Calcium Channels Drive Excitatory and Inhibitory Neuronal Network Development. J Neurosci 2020; 40:4824-4841. [PMID: 32414783 PMCID: PMC7326358 DOI: 10.1523/jneurosci.1707-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 03/31/2020] [Accepted: 05/09/2020] [Indexed: 01/21/2023] Open
Abstract
VGCCs are multisubunit complexes that play a crucial role in neuronal signaling. Auxiliary α2δ subunits of VGCCs modulate trafficking and biophysical properties of the pore-forming α1 subunit and trigger excitatory synaptogenesis. Alterations in the expression level of α2δ subunits were implicated in several syndromes and diseases, including chronic neuropathic pain, autism, and epilepsy. However, the contribution of distinct α2δ subunits to excitatory/inhibitory imbalance and aberrant network connectivity characteristic for these pathologic conditions remains unclear. Here, we show that α2δ1 overexpression enhances spontaneous neuronal network activity in developing and mature cultures of hippocampal neurons. In contrast, overexpression, but not downregulation, of α2δ3 enhances neuronal firing in immature cultures, whereas later in development it suppresses neuronal activity. We found that α2δ1 overexpression increases excitatory synaptic density and selectively enhances presynaptic glutamate release, which is impaired on α2δ1 knockdown. Overexpression of α2δ3 increases the excitatory synaptic density as well but also facilitates spontaneous GABA release and triggers an increase in the density of inhibitory synapses, which is accompanied by enhanced axonaloutgrowth in immature interneurons. Together, our findings demonstrate that α2δ1 and α2δ3 subunits play distinct but complementary roles in driving formation of structural and functional network connectivity during early development. An alteration in α2δ surface expression during critical developmental windows can therefore play a causal role and have a profound impact on the excitatory-to-inhibitory balance and network connectivity.SIGNIFICANCE STATEMENT The computational capacity of neuronal networks is determined by their connectivity. Chemical synapses are the main interface for transfer of information between individual neurons. The initial formation of network connectivity requires spontaneous electrical activity and the calcium channel-mediated signaling. We found that, in early development, auxiliary α2δ3 subunits of calcium channels foster presynaptic release of GABA, trigger formation of inhibitory synapses, and promote axonal outgrowth in inhibitory interneurons. In contrast, later in development, α2δ1 subunits promote the glutamatergic neurotransmission and synaptogenesis, as well as strongly enhance neuronal network activity. We propose that formation of connectivity in neuronal networks is associated with a concerted interplay of α2δ1 and α2δ3 subunits of calcium channels.
Collapse
Affiliation(s)
- Arthur Bikbaev
- RG Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Anna Ciuraszkiewicz-Wojciech
- RG Molecular Physiology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Magdeburg, 39106, Germany
| | - Jennifer Heck
- RG Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Oliver Klatt
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Romy Freund
- RG Molecular Physiology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
| | - Jessica Mitlöhner
- RG Brain Extracellular Matrix, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
| | - Sara Enrile Lacalle
- RG Molecular Physiology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
| | - Miao Sun
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Daniele Repetto
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Renato Frischknecht
- RG Brain Extracellular Matrix, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
- Department of Biology, Animal Physiology, Friedrich Alexander University of Erlangen-Nuremberg, Erlangen, 91058, Germany
| | - Cornelia Ablinger
- Institute of Physiology, Medical University Innsbruck, Innsbruck, 6020, Austria
| | - Astrid Rohlmann
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Markus Missler
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Gerald J Obermair
- Division Physiology, Karl Landsteiner University of Health Sciences, Krems, 3500, Austria
| | - Valentina Di Biase
- Institute of Molecular and Clinical Pharmacology, Medical University Innsbruck, Innsbruck, 6020, Austria
| | - Martin Heine
- RG Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Magdeburg, 39106, Germany
| |
Collapse
|
9
|
Risher WC, Eroglu C. Emerging roles for α2δ subunits in calcium channel function and synaptic connectivity. Curr Opin Neurobiol 2020; 63:162-169. [PMID: 32521436 DOI: 10.1016/j.conb.2020.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/29/2020] [Indexed: 12/17/2022]
Abstract
Central nervous system function requires the proper formation and function of synapses. The α2δ auxiliary subunits of voltage-gated calcium channels have emerged as regulators of a number of critical events associated with regulation of synaptic function, including channel trafficking and localization, as well as the initial establishment of synaptic structures. In this review, we will discuss some of these recent studies which have uncovered novel mechanisms for α2δ function at the synapse, including the regulation of calcium channel α1 subunit specificity and the promotion of dendritic spine growth. Moreover, we will cover recent advances that have been made in understanding the consequences of aberrant α2δ signaling in injury and disease.
Collapse
Affiliation(s)
- William Christopher Risher
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV 25705, United States.
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, United States; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, United States; Duke Institute for Brain Sciences (DIBS), Durham, NC 27710, United States; Regeneration Next Initiative, Duke University, Durham, NC 27710, United States
| |
Collapse
|
10
|
Calcium Channel Subunit α2δ4 Is Regulated by Early Growth Response 1 and Facilitates Epileptogenesis. J Neurosci 2019; 39:3175-3187. [PMID: 30792272 DOI: 10.1523/jneurosci.1731-18.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 12/03/2018] [Accepted: 01/08/2019] [Indexed: 12/17/2022] Open
Abstract
Transient brain insults, including status epilepticus (SE), can trigger a period of epileptogenesis during which functional and structural reorganization of neuronal networks occurs resulting in the onset of focal epileptic seizures. In recent years, mechanisms that regulate the dynamic transcription of individual genes during epileptogenesis and thereby contribute to the development of a hyperexcitable neuronal network have been elucidated. Our own results have shown early growth response 1 (Egr1) to transiently increase expression of the T-type voltage-dependent Ca2+ channel (VDCC) subunit CaV3.2, a key proepileptogenic protein. However, epileptogenesis involves complex and dynamic transcriptomic alterations; and so far, our understanding of the transcriptional control mechanism of gene regulatory networks that act in the same processes is limited. Here, we have analyzed whether Egr1 acts as a key transcriptional regulator for genes contributing to the development of hyperexcitability during epileptogenesis. We found Egr1 to drive the expression of the VDCC subunit α2δ4, which was augmented early and persistently after pilocarpine-induced SE. Furthermore, we show that increasing levels of α2δ4 in the CA1 region of the hippocampus elevate seizure susceptibility of mice by slightly decreasing local network activity. Interestingly, we also detected increased expression levels of Egr1 and α2δ4 in human hippocampal biopsies obtained from epilepsy surgery. In conclusion, Egr1 controls the abundance of the VDCC subunits CaV3.2 and α2δ4, which act synergistically in epileptogenesis, and thereby contributes to a seizure-induced "transcriptional Ca2+ channelopathy."SIGNIFICANCE STATEMENT The onset of focal recurrent seizures often occurs after an epileptogenic process induced by transient insults to the brain. Recently, transcriptional control mechanisms for individual genes involved in converting neurons hyperexcitable have been identified, including early growth response 1 (Egr1), which activates transcription of the T-type Ca2+ channel subunit CaV3.2. Here, we find Egr1 to regulate also the expression of the voltage-dependent Ca2+ channel subunit α2δ4, which was augmented after pilocarpine- and kainic acid-induced status epilepticus. In addition, we observed that α2δ4 affected spontaneous network activity and the susceptibility for seizure induction. Furthermore, we detected corresponding dynamics in human biopsies from epilepsy patients. In conclusion, Egr1 orchestrates a seizure-induced "transcriptional Ca2+ channelopathy" consisting of CaV3.2 and α2δ4, which act synergistically in epileptogenesis.
Collapse
|
11
|
de Oliveira C, de Freitas JS, Macedo IC, Scarabelot VL, Ströher R, Santos DS, Souza A, Fregni F, Caumo W, Torres ILS. Transcranial direct current stimulation (tDCS) modulates biometric and inflammatory parameters and anxiety-like behavior in obese rats. Neuropeptides 2019; 73:1-10. [PMID: 30446297 DOI: 10.1016/j.npep.2018.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 07/14/2018] [Accepted: 09/19/2018] [Indexed: 12/16/2022]
Abstract
Obesity is a multifactorial disease associated with metabolic dysfunction and the prevention and treatment of obesity are often unsatisfactory. Transcranial direct-current stimulation (tDCS) is a non-invasive brain stimulation technique that has proven promising in the treatment of eating disorders such as obesity. We investigate the effects of tDCS on locomotor and exploratory activities, anxiety-like and feeding behavior, and levels of brain-derived neurotrophic factor (BDNF), IL (interleukin)-10, IL-1β, and tumor necrosis factor-alpha (TNF-α) in the cerebral cortex of obese rats. A total of 40 adult male Wistar rats were used in our study. Animals were divided into groups of three or four animals per cage and allocated to four treatment groups: standard diet plus sham tDCS treatment (SDS), standard diet plus tDCS treatment (SDT), hypercaloric diet plus sham tDCS treatment (HDS), hypercaloric diet plus tDCS treatment (HDT). After 40 days on a hypercaloric diet and/or standard diet were to assessed the locomotor and exploratory activity and anxiety-like behavior to by the open field (OF) and elevated plus maze (EPM) tests respectively before and after exposure to tDCS treatment. The experimental groups were submitted to active or sham treatment tDCS during eight days. Palatable food consumption test (PFT) was performed 24 h after the last tDCS session under fasting and feeding conditions. Obese animals submitted to tDCS treatment showed a reduction in the Lee index, visceral adipose tissue weight, and food craving. In addition, bicephalic tDCS decreased the cerebral cortex levels of IL-1β and TNF-α in these animals. Exposure to a hypercaloric diet produced an anxiolytic effect, which was reversed by bicephalic tDCS treatment. These results suggest that, in accordance with studies in humans, bicephalic tDCS could modulate biometric and inflammatory parameters, as well as anxiety-like and feeding behavior, of rats subjected to the consumption of a hypercaloric diet.
Collapse
Affiliation(s)
- Carla de Oliveira
- Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post-Graduate Program in Medicine: Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Joice Soares de Freitas
- Post-Graduate Program in Biological Sciences, Pharmacology and Therapeutics, Institute of Basic Health Sciences, Universidade Federal Rio Grande do Sul, Porto Alegre, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Isabel Cristina Macedo
- Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Vanessa Leal Scarabelot
- Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Roberta Ströher
- Post-Graduate Program in Biological Sciences, Pharmacology and Therapeutics, Institute of Basic Health Sciences, Universidade Federal Rio Grande do Sul, Porto Alegre, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Daniela Silva Santos
- Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post-Graduate Program in Medicine: Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Andressa Souza
- Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil
| | - Felipe Fregni
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Wolnei Caumo
- Post-Graduate Program in Medicine: Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Iraci L S Torres
- Post-Graduate Program in Biological Sciences, Pharmacology and Therapeutics, Institute of Basic Health Sciences, Universidade Federal Rio Grande do Sul, Porto Alegre, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Pre clinical studies, Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post-Graduate Program in Medicine: Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
| |
Collapse
|
12
|
Baldo B, Gabery S, Soylu-Kucharz R, Cheong RY, Henningsen JB, Englund E, McLean C, Kirik D, Halliday G, Petersén Å. SIRT1 is increased in affected brain regions and hypothalamic metabolic pathways are altered in Huntington disease. Neuropathol Appl Neurobiol 2018; 45:361-379. [PMID: 30019499 DOI: 10.1111/nan.12514] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/11/2018] [Indexed: 01/03/2023]
Abstract
AIMS Metabolic dysfunction is involved in modulating the disease process in Huntington disease (HD) but the underlying mechanisms are not known. The aim of this study was to investigate if the metabolic regulators sirtuins are affected in HD. METHODS Quantitative real-time polymerase chain reactions were used to assess levels of SIRT1-3 and downstream targets in post mortem brain tissue from HD patients and control cases as well as after selective hypothalamic expression of mutant huntingtin (HTT) using recombinant adeno-associated viral vectors in mice. RESULTS We show that mRNA levels of the metabolic regulator SIRT1 are increased in the striatum and the cerebral cortex but not in the less affected cerebellum in post mortem HD brains. Levels of SIRT2 are only increased in the striatum and SIRT3 is not affected in HD. Interestingly, mRNA levels of SIRT1 are selectively increased in the lateral hypothalamic area (LHA) and ventromedial hypothalamus (VMH) in HD. Further analyses of the LHA and VMH confirmed pathological changes in these regions including effects on SIRT1 downstream targets and reduced mRNA levels of orexin (hypocretin), prodynorphin and melanin-concentrating hormone (MCH) in the LHA and of brain-derived neurotrophic factor (BDNF) in the VMH. Analyses after selective hypothalamic expression of mutant HTT suggest that effects on BDNF, orexin, dynorphin and MCH are early and direct, whereas changes in SIRT1 require more widespread expression of mutant HTT. CONCLUSIONS We show that SIRT1 expression is increased in HD-affected brain regions and that metabolic pathways are altered in the HD hypothalamus.
Collapse
Affiliation(s)
- B Baldo
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - S Gabery
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - R Soylu-Kucharz
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - R Y Cheong
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - J B Henningsen
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - E Englund
- Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - C McLean
- Department of Pathology, Alfred Hospital, Melbourne, Vic, Australia
| | - D Kirik
- B.R.A.I.N.S. Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - G Halliday
- Brain and Mind Centre, Sydney Medical School, UNSW Medicine and NeuRA, The University of Sydney, Sydney, NSW, Australia
| | - Å Petersén
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| |
Collapse
|
13
|
α-Neurexins Together with α2δ-1 Auxiliary Subunits Regulate Ca 2+ Influx through Ca v2.1 Channels. J Neurosci 2018; 38:8277-8294. [PMID: 30104341 DOI: 10.1523/jneurosci.0511-18.2018] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/03/2018] [Accepted: 07/10/2018] [Indexed: 11/21/2022] Open
Abstract
Action potential-evoked neurotransmitter release is impaired in knock-out neurons lacking synaptic cell-adhesion molecules α-neurexins (αNrxns), the extracellularly longer variants of the three vertebrate Nrxn genes. Ca2+ influx through presynaptic high-voltage gated calcium channels like the ubiquitous P/Q-type (CaV2.1) triggers release of fusion-ready vesicles at many boutons. α2δ Auxiliary subunits regulate trafficking and kinetic properties of CaV2.1 pore-forming subunits but it has remained unclear if this involves αNrxns. Using live cell imaging with Ca2+ indicators, we report here that the total presynaptic Ca2+ influx in primary hippocampal neurons of αNrxn triple knock-out mice of both sexes is reduced and involved lower CaV2.1-mediated transients. This defect is accompanied by lower vesicle release, reduced synaptic abundance of CaV2.1 pore-forming subunits, and elevated surface mobility of α2δ-1 on axons. Overexpression of Nrxn1α in αNrxn triple knock-out neurons is sufficient to restore normal presynaptic Ca2+ influx and synaptic vesicle release. Moreover, coexpression of Nrxn1α together with α2δ-1 subunits facilitates Ca2+ influx further but causes little augmentation together with a different subunit, α2δ-3, suggesting remarkable specificity. Expression of defined recombinant CaV2.1 channels in heterologous cells validates and extends the findings from neurons. Whole-cell patch-clamp recordings show that Nrxn1α in combination with α2δ-1, but not with α2δ-3, facilitates Ca2+ currents of recombinant CaV2.1 without altering channel kinetics. These results suggest that presynaptic Nrxn1α acts as a positive regulator of Ca2+ influx through CaV2.1 channels containing α2δ-1 subunits. We propose that this regulation represents an important way for neurons to adjust synaptic strength.SIGNIFICANCE STATEMENT Synaptic transmission between neurons depends on the fusion of neurotransmitter-filled vesicles with the presynaptic membrane, which subsequently activates postsynaptic receptors. Influx of calcium ions into the presynaptic terminal is the key step to trigger vesicle release and involves different subtypes of voltage-gated calcium channels. We study the regulation of calcium channels by neurexins, a family of synaptic cell-adhesion molecules that are essential for many synapse properties. Using optical measurements of calcium influx in cultured neurons and electrophysiological recordings of calcium currents from recombinant channels, we show that a major neurexin variant facilitates calcium influx through P/Q-type channels by interacting with their α2δ-1 auxiliary subunits. These results propose a novel way how neurons can modulate the strength of distinct synapses.
Collapse
|
14
|
Felsted JA, Chien CH, Wang D, Panessiti M, Ameroso D, Greenberg A, Feng G, Kong D, Rios M. Alpha2delta-1 in SF1 + Neurons of the Ventromedial Hypothalamus Is an Essential Regulator of Glucose and Lipid Homeostasis. Cell Rep 2018; 21:2737-2747. [PMID: 29212022 DOI: 10.1016/j.celrep.2017.11.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 10/06/2017] [Accepted: 11/13/2017] [Indexed: 12/29/2022] Open
Abstract
The central mechanisms controlling glucose and lipid homeostasis are inadequately understood. We show that α2δ-1 is an essential regulator of glucose and lipid balance, acting in steroidogenic factor-1 (SF1) neurons of the ventromedial hypothalamus (VMH). These effects are body weight independent and involve regulation of SF1+ neuronal activity and sympathetic output to metabolic tissues. Accordingly, mice with α2δ-1 deletion in SF1 neurons exhibit glucose intolerance, altered lipolysis, and decreased cholesterol content in adipose tissue despite normal energy balance regulation. Profound reductions in the firing rate of SF1 neurons, decreased sympathetic output, and elevated circulating levels of serotonin are associated with these alterations. Normal calcium currents but reduced excitatory postsynaptic currents in mutant SF1 neurons implicate α2δ-1 in the promotion of excitatory synaptogenesis separate from its canonical role as a calcium channel subunit. Collectively, these findings identify an essential mechanism that regulates VMH neuronal activity and glycemic and lipid control and may be a target for tackling metabolic disease.
Collapse
Affiliation(s)
- Jennifer A Felsted
- Graduate Program in Biochemical and Molecular Nutrition, Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA 02111, USA
| | - Cheng-Hao Chien
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Dongqing Wang
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Micaella Panessiti
- Graduate Program in Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Dominique Ameroso
- Graduate Program in Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Andrew Greenberg
- Graduate Program in Biochemical and Molecular Nutrition, Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA 02111, USA; USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA
| | - Guoping Feng
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dong Kong
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Maribel Rios
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Neuroscience, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA.
| |
Collapse
|
15
|
Elibol B, Kilic U. High Levels of SIRT1 Expression as a Protective Mechanism Against Disease-Related Conditions. Front Endocrinol (Lausanne) 2018; 9:614. [PMID: 30374331 PMCID: PMC6196295 DOI: 10.3389/fendo.2018.00614] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/27/2018] [Indexed: 01/11/2023] Open
Abstract
SIRT1 protein, a member of Silent Information Regulator 2 (Sir2) protein family, have gained considerable attention as epigenetic regulators for a great area in the human physiology. Changes in sirtuin expression are critical in several diseases, including metabolic syndrome, cardiovascular diseases, cancer and neurodegeneration. Here, we provide an overview of the association of the increasing level of SIRT1 protein for regulating some disease related conditions such as obesity, cardiovascular diseases and neurodegeneration. This review also provides a detailed molecular understanding of the interaction of the some basic molecules with increasing SIRT1 levels rather than reduction of the SIRT1 expression. In this context, the current approaches to enhancing the expression of SIRT1 points the importance of epigenetics in several age-related diseases to provide a healthy aging by developing novel therapies which can prevent or damp the progression of some diseases.
Collapse
Affiliation(s)
- Birsen Elibol
- Department of Medical Biology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Ulkan Kilic
- Department of Medical Biology, Faculty of Medicine, University of Health Sciences, Istanbul, Turkey
- *Correspondence: Ulkan Kilic
| |
Collapse
|
16
|
Harcourt BE, Bullen DVR, Kao KT, Tassoni D, Alexander EJ, Burgess T, White SM, Sabin MA. Maternal inheritance of BDNF deletion, with phenotype of obesity and developmental delay in mother and child. Am J Med Genet A 2017; 176:194-200. [PMID: 29160031 DOI: 10.1002/ajmg.a.38539] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 09/28/2017] [Accepted: 10/08/2017] [Indexed: 12/21/2022]
Abstract
Childhood obesity is a significant world health problem. Understanding the genetic and environmental factors contributing to the development of obesity in childhood is important for the rational design of strategies for obesity prevention and treatment. Brain-derived neurotrophic factor (BDNF) plays an important role in the growth and development of the central nervous system, there is also an evidence that BDNF plays a role in regulation of appetite. Disruption of the expression of this gene in a child has been previously reported to result in a phenotype of severe obesity, hyperphagia, impaired cognitive function, and hyperactivity. We report a mother and child, both with micro-deletions encompassing the BDNF gene locus, who both have obesity and developmental delay, although without hyperactivity. This report highlights the maternal inheritance of a rare genetic cause of childhood obesity.
Collapse
Affiliation(s)
- Brooke E Harcourt
- Obesity Research, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia.,Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Australia.,Mater Research Institute-UQ, The University of Queensland, Brisbane, Australia
| | | | - Kung-Ting Kao
- Obesity Research, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia.,Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Australia
| | | | - Erin J Alexander
- Obesity Research, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Australia
| | - Trent Burgess
- Victorian Clinical Genetic Services, The Royal Children's Hospital, Melbourne, Australia
| | - Susan M White
- Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia.,Victorian Clinical Genetic Services, The Royal Children's Hospital, Melbourne, Australia.,Murdoch Childrens Research Institute, Parkville, Australia
| | - Matthew A Sabin
- Obesity Research, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia.,Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Australia
| |
Collapse
|
17
|
Zhang Y, Reichel JM, Han C, Zuniga-Hertz JP, Cai D. Astrocytic Process Plasticity and IKKβ/NF-κB in Central Control of Blood Glucose, Blood Pressure, and Body Weight. Cell Metab 2017; 25:1091-1102.e4. [PMID: 28467927 PMCID: PMC5576872 DOI: 10.1016/j.cmet.2017.04.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/07/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022]
Abstract
Central regulation of metabolic physiology is mediated critically through neuronal functions; however, whether astrocytes are also essential remains unclear. Here we show that the high-order processes of astrocytes in the mediobasal hypothalamus displayed shortening in fasting and elongation in fed status. Chronic overnutrition and astrocytic IKKβ/NF-κB upregulation similarly impaired astrocytic plasticity, leading to sustained shortening of high-order processes. In physiology, astrocytic IKKβ/NF-κB upregulation resulted in early-onset effects, including glucose intolerance and blood pressure rise, and late-onset effects, including body weight and fat gain. Appropriate inhibition in astrocytic IKKβ/NF-κB protected against chronic overnutrition impairing astrocytic plasticity and these physiological functions. Mechanistically, astrocytic regulation of hypothalamic extracellular GABA level and therefore BDNF expression were found partly accountable. Hence, astrocytic process plasticity and IKKβ/NF-κB play significant roles in central control of blood glucose, blood pressure, and body weight as well as the central induction of these physiological disorders leading to disease.
Collapse
Affiliation(s)
- Yalin Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Judith M Reichel
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Cheng Han
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Juan Pablo Zuniga-Hertz
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute of Aging, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| |
Collapse
|
18
|
Abstract
Energy balance--that is, the relationship between energy intake and energy expenditure--is regulated by a complex interplay of hormones, brain circuits and peripheral tissues. Leptin is an adipocyte-derived cytokine that suppresses appetite and increases energy expenditure. Ironically, obese individuals have high levels of plasma leptin and are resistant to leptin treatment. Neurotrophic factors, particularly ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF), are also important for the control of body weight. CNTF can overcome leptin resistance in order to reduce body weight, although CNTF and leptin activate similar signalling cascades. Mutations in the gene encoding BDNF lead to insatiable appetite and severe obesity.
Collapse
Affiliation(s)
- Baoji Xu
- Department of Neuroscience, The Scripps Research Institute Florida, 130 Scripps Way, Jupiter, Florida 33458, USA
| | - Xiangyang Xie
- Department of Neuroscience, The Scripps Research Institute Florida, 130 Scripps Way, Jupiter, Florida 33458, USA
| |
Collapse
|
19
|
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.
Collapse
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.
| |
Collapse
|
20
|
Medici V, McClave SA, Miller KR. Common Medications Which Lead to Unintended Alterations in Weight Gain or Organ Lipotoxicity. Curr Gastroenterol Rep 2016; 18:2. [PMID: 26700070 DOI: 10.1007/s11894-015-0479-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Obesity is one of the most common chronic conditions in the world. Its management is difficult, partly due to the multiple associated comorbidities including fatty liver, diabetes, hypertension, and hyperlipidemia. As a result, the choice of prescription medications in overweight and obese patients has important implications as some of them can actually worsen the fat accumulation and its associated metabolic complications. Several prescription medications are associated with weight gain with mechanisms that are often poorly understood and under-recognized. Even less data are available on the distribution of fat and lipotoxicity (the organ damage related to fat accumulation). The present review will discuss the drugs associated with weight gain, their mechanism of action, and the magnitude and timing of their effect.
Collapse
Affiliation(s)
- Valentina Medici
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis, 4150 V Street, Sacramento, CA, 95816, USA.
| | - Stephen A McClave
- Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Louisville School of Medicine, 550 South Jackson Street, Louisville, KY, 40202, USA.
| | - Keith R Miller
- Department of Surgery, University of Louisville, ACB 2nd Floor, 550 South Jackson Street, Louisville, KY, 40202, USA.
| |
Collapse
|
21
|
Zhou C, Luo ZD. Nerve injury-induced calcium channel alpha-2-delta-1 protein dysregulation leads to increased pre-synaptic excitatory input into deep dorsal horn neurons and neuropathic allodynia. Eur J Pain 2015; 19:1267-76. [PMID: 25691360 DOI: 10.1002/ejp.656] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND Up-regulation of voltage-gated calcium channel α2 δ1 subunit post spinal nerve ligation (SNL) injury or in α2 δ1 -overexpressing transgenic (Tg) mice correlates with tactile allodynia, a pain state mediated mainly by Aβ sensory fibres forming synaptic connections with deep dorsal horn (DDH) neurons. It is not clear, however, whether dysregulated α2 δ1 alters DDH synaptic neurotransmission that underlies tactile allodynia development post nerve injury. METHODS Tactile allodynia was tested in the SNL and α2 δ1 Tg models. Miniature excitatory/inhibitory post-synaptic currents were recorded in DDH neurons from these animal models using whole-cell patch clamp slice recording techniques. RESULTS There was a significant increase in the frequency, but not amplitude, of miniature excitatory post-synaptic currents (mEPSC) in DDH neurons that correlated with tactile allodynia in SNL and α2 δ1 Tg mice. Gabapentin, an α2 δ1 ligand that is known to block tactile allodynia in these models, also normalized mEPSC frequency dose-dependently in DDH neurons from SNL and α2 δ1 Tg mice. In contrast, neither frequency nor amplitude of miniature inhibitory post-synaptic currents was altered in DDH neurons from SNL and α2 δ1 Tg mice. CONCLUSION Our data suggest that α2 δ1 dysregulation is highly likely contributing to tactile allodynia through a pre-synaptic mechanism involving facilitation of excitatory synaptic neurotransmission in DDH of spinal cord.
Collapse
Affiliation(s)
- C Zhou
- Department of Pharmacology, School of Medicine, University of California Irvine, USA
| | - Z D Luo
- Department of Pharmacology, School of Medicine, University of California Irvine, USA.,Department of Anesthesiology and Perioperative Care, School of Medicine, University of California Irvine, USA
| |
Collapse
|
22
|
Numakawa T, Richards M, Nakajima S, Adachi N, Furuta M, Odaka H, Kunugi H. The role of brain-derived neurotrophic factor in comorbid depression: possible linkage with steroid hormones, cytokines, and nutrition. Front Psychiatry 2014; 5:136. [PMID: 25309465 PMCID: PMC4175905 DOI: 10.3389/fpsyt.2014.00136] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/12/2014] [Indexed: 01/09/2023] Open
Abstract
Increasing evidence demonstrates a connection between growth factor function (including brain-derived neurotrophic factor, BDNF), glucocorticoid levels (one of the steroid hormones), and the pathophysiology of depressive disorders. Because both BDNF and glucocorticoids regulate synaptic function in the central nervous system, their functional interaction is of major concern. Interestingly, alterations in levels of estrogen, another steroid hormone, may play a role in depressive-like behavior in postpartum females with fluctuations of BDNF-related molecules in the brain. BDNF and cytokines, which are protein regulators of inflammation, stimulate multiple intracellular signaling cascades involved in neuropsychiatric illness. Pro-inflammatory cytokines may increase vulnerability to depressive symptoms, such as the increased risk observed in patients with cancer and/or autoimmune diseases. In this review, we discuss the possible relationship between inflammation and depression, in addition to the cross-talk among cytokines, BDNF, and steroids. Further, since nutritional status has been shown to affect critical pathways involved in depression through both BDNF function and the monoamine system, we also review current evidence surrounding diet and supplementation (e.g., flavonoids) on BDNF-mediated brain functions.
Collapse
Affiliation(s)
- Tadahiro Numakawa
- Department of Mental Disorder Research, National Center of Neurology and Psychiatry, National Institute of Neuroscience , Tokyo , Japan
| | - Misty Richards
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles , Los Angeles, CA , USA
| | - Shingo Nakajima
- Department of Mental Disorder Research, National Center of Neurology and Psychiatry, National Institute of Neuroscience , Tokyo , Japan
| | - Naoki Adachi
- Department of Mental Disorder Research, National Center of Neurology and Psychiatry, National Institute of Neuroscience , Tokyo , Japan
| | - Miyako Furuta
- Department of Physiology, St. Marianna University School of Medicine , Kanagawa , Japan
| | - Haruki Odaka
- Department of Mental Disorder Research, National Center of Neurology and Psychiatry, National Institute of Neuroscience , Tokyo , Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Center of Neurology and Psychiatry, National Institute of Neuroscience , Tokyo , Japan
| |
Collapse
|