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Liu J, Li N, Wei C, Han F, Deng M, Ma J, Zou X, Zhou Y, Yang R, Yuan H. GHS-R1a deficiency protects against lipopolysaccharide-induced spatial memory impairment in mice. Biochem Biophys Res Commun 2024; 727:150270. [PMID: 38917617 DOI: 10.1016/j.bbrc.2024.150270] [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: 05/15/2024] [Accepted: 06/15/2024] [Indexed: 06/27/2024]
Abstract
Neuroinflammation has been implicated in cognitive deficits of neurological and neurodegenerative diseases. There is abundant evidence that the application of ghrelin, an orexigenic hormone regulating appetite and energy balance, abrogates neuroinflammation and rescues associated memory impairment. However, the underlying mechanism is uncertain. In this study, we find that both intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of lipopolysaccharide (LPS) impairs spatial memory in mice. LPS treatment causes neuroinflammation and microglial activation in the hippocampus. Ghsr1a deletion suppresses LPS-induced microglial activation and neuroinflammation, and rescued LPS-induced memory impairment. Our findings thus suggest that GHS-R1a signaling may promote microglial immunoactivation and contribute to LPS-induced neuroinflammation. GHS-R1a may be a new therapeutic target for cognitive dysfunction associated with inflammatory conditions.
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Affiliation(s)
- Junru Liu
- Department of Neurology, Affiliated Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Medical Group)Qingdao, Shandong 266042, China; Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China
| | - Na Li
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Department of Medicine, Qingdao Binhai University, Qingdao, Shandong, 266555, China
| | - Chuang Wei
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Fubing Han
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Department of Neurosurgery, Affiliated Hospital of Qingdao University, Qingdao, Shandong, 266000, China
| | - Mingru Deng
- Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China; Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Jialin Ma
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Xueying Zou
- Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China
| | - Yu Zhou
- Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China; Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Affiliated Qingdao Third People's Hospital, Department of Otorhinolaryngology Head and Neck, Qingdao University, Qingdao, 266021, China.
| | - Rong Yang
- Affiliated Qingdao Third People's Hospital, Department of Otorhinolaryngology Head and Neck, Qingdao University, Qingdao, 266021, China.
| | - Haicheng Yuan
- Department of Neurology, Affiliated Qingdao Central Hospital, University of Health and Rehabilitation Sciences (Qingdao Central Medical Group)Qingdao, Shandong 266042, China; Department of Neurology, School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261053, China.
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Sadee W. Ligand-Free Signaling of G-Protein-Coupled Receptors: Physiology, Pharmacology, and Genetics. Molecules 2023; 28:6375. [PMID: 37687205 PMCID: PMC10489045 DOI: 10.3390/molecules28176375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) are ubiquitous sensors and regulators of cellular functions. Each GPCR exists in complex aggregates with multiple resting and active conformations. Designed to detect weak stimuli, GPCRs can also activate spontaneously, resulting in basal ligand-free signaling. Agonists trigger a cascade of events leading to an activated agonist-receptor G-protein complex with high agonist affinity. However, the ensuing signaling process can further remodel the receptor complex to reduce agonist affinity, causing rapid ligand dissociation. The acutely activated ligand-free receptor can continue signaling, as proposed for rhodopsin and μ opioid receptors, resulting in robust receptor activation at low agonist occupancy with enhanced agonist potency. Continued receptor stimulation can further modify the receptor complex, regulating sustained ligand-free signaling-proposed to play a role in opioid dependence. Basal, acutely agonist-triggered, and sustained elevated ligand-free signaling could each have distinct functions, reflecting multi-state conformations of GPCRs. This review addresses basal and stimulus-activated ligand-free signaling, its regulation, genetic factors, and pharmacological implications, focusing on opioid and serotonin receptors, and the growth hormone secretagogue receptor (GHSR). The hypothesis is proposed that ligand-free signaling of 5-HT2A receptors mediate therapeutic effects of psychedelic drugs. Research avenues are suggested to close the gaps in our knowledge of ligand-free GPCR signaling.
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Affiliation(s)
- Wolfgang Sadee
- Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA;
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
- Aether Therapeutics Inc., Austin, TX 78756, USA
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McCarthy CI, Mustafá ER, Cornejo MP, Yaneff A, Rodríguez SS, Perello M, Raingo J. Chlorpromazine, an Inverse Agonist of D1R-Like, Differentially Targets Voltage-Gated Calcium Channel (Ca V) Subtypes in mPFC Neurons. Mol Neurobiol 2023; 60:2644-2660. [PMID: 36694048 DOI: 10.1007/s12035-023-03221-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/04/2023] [Indexed: 01/26/2023]
Abstract
The dopamine receptor type 1 (D1R) and the dopamine receptor type 5 (D5R), which are often grouped as D1R-like due to their sequence and signaling similarities, exhibit high levels of constitutive activity. The molecular basis for this agonist-independent activation has been well characterized through biochemical and mutagenesis in vitro studies. In this regard, it was reported that many antipsychotic drugs act as inverse agonists of D1R-like constitutive activity. On the other hand, D1R is highly expressed in the medial prefrontal cortex (mPFC), a brain area with important functions such as working memory. Here, we studied the impact of D1R-like constitutive activity and chlorpromazine (CPZ), an antipsychotic drug and D1R-like inverse agonist, on various neuronal CaV conductances, and we explored its effect on calcium-dependent neuronal functions in the mouse medial mPFC. Using ex vivo brain slices containing the mPFC and transfected HEK293T cells, we found that CPZ reduces CaV2.2 currents by occluding D1R-like constitutive activity, in agreement with a mechanism previously reported by our lab, whereas CPZ directly inhibits CaV1 currents in a D1R-like activity independent manner. In contrast, CPZ and D1R constitutive activity did not affect CaV2.1, CaV2.3, or CaV3 currents. Finally, we found that CPZ reduces excitatory postsynaptic responses in mPFC neurons. Our results contribute to understanding CPZ molecular targets in neurons and describe a novel physiological consequence of CPZ non-canonical action as a D1R-like inverse agonist in the mouse brain.
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Affiliation(s)
- Clara Inés McCarthy
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology (Argentine Research Council CONICET, Scientific Research Commission of the Buenos Aires Province and National University of La Plata), La Plata, Buenos Aires, Argentina
| | - Emilio Román Mustafá
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology (Argentine Research Council CONICET, Scientific Research Commission of the Buenos Aires Province and National University of La Plata), La Plata, Buenos Aires, Argentina
| | - María Paula Cornejo
- Neurophysiology Laboratory of the Multidisciplinary Institute of Cell Biology (Argentine Research Council CONICET, Scientific Research Commission of the Buenos Aires Province and National University of La Plata), La Plata, Buenos Aires, Argentina
| | - Agustín Yaneff
- Instituto de Investigaciones Farmacológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Silvia Susana Rodríguez
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology (Argentine Research Council CONICET, Scientific Research Commission of the Buenos Aires Province and National University of La Plata), La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Neurophysiology Laboratory of the Multidisciplinary Institute of Cell Biology (Argentine Research Council CONICET, Scientific Research Commission of the Buenos Aires Province and National University of La Plata), La Plata, Buenos Aires, Argentina
- Department of Surgical Sciences, Functional Pharmacology and Neuroscience, University of Uppsala, Uppsala, Sweden
| | - Jesica Raingo
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology (Argentine Research Council CONICET, Scientific Research Commission of the Buenos Aires Province and National University of La Plata), La Plata, Buenos Aires, Argentina.
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Li N, Li N, Yang L, Gu H, Ji J, Zhou H, Zhu Q, Yu M, Sun Y, Zhou Y. GHSR1a deficiency suppresses inhibitory drive on dCA1 pyramidal neurons and contributes to memory reinforcement. Cereb Cortex 2023; 33:2612-2625. [PMID: 35797708 DOI: 10.1093/cercor/bhac230] [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] [Received: 04/08/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 11/12/2022] Open
Abstract
Growth hormone secretagogue receptor 1a (GHSR1a)-the receptor for orexigenic hormone ghrelin-is a G protein-coupled receptor that is widely distributed in the brain, including the hippocampus. Studies have demonstrated that genetic deletion of GHSR1a affects memory, suggesting the importance of ghrelin/GHSR1a signaling in cognitive control. However, current reports are controversial, and the mechanism underlying GHSR1a modulation of memory is uncertain. Here, we first report that global GHSR1a knockout enhances hippocampus-dependent memory, facilitates initial LTP in dorsal hippocampal Schaffer Collateral-CA1 synapses, and downregulates Akt activity in the hippocampus. Moreover, we show that the intrinsic excitability of GAD67+ interneurons-rather than neighboring pyramidal neurons in the dCA1-is suppressed by GHSR1a deletion, an effect that is antagonized by acute application of the Akt activator SC79. In addition, the inhibitory postsynaptic currents (IPSCs) on dCA1 pyramidal neurons are selectively reduced in mice with a GHSR1a deficiency. Finally, we demonstrate that selectively increasing the excitability of parvalbumin-expressing interneurons by hM3Dq-DREADDs increases IPSCs on dCA1 pyramidal neurons and normalizes memory in Ghsr1a KO mice. Our findings thus reveal a novel mechanism underlying memory enhancement of GHSR1a deficiency and herein support an adverse effect of GHSR1a signaling in hippocampus-dependent memory processes.
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Affiliation(s)
- Na Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Medicine, Qingdao Binhai University, 425 West Jialing River Rd, Qingdao, Shandong, 266555, China
| | - Nan Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Health and Life Sciences, University of Health and Rehabilitation Sciences, 17 Shandong Rd, Qingdao, Shandong, 266000, China
| | - Liu Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Huating Gu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Junjie Ji
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Hao Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Qianqian Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
| | - Ming Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Health and Life Sciences, University of Health and Rehabilitation Sciences, 17 Shandong Rd, Qingdao, Shandong, 266000, China
| | - Yuxiang Sun
- Department of Nutrition, Texas A&M University, 750 Agronomy Rd, College Station, TX, 77843, United States
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, 308 Ningxia Rd, Qingdao, Shandong, 266071, China
- Department of Health and Life Sciences, University of Health and Rehabilitation Sciences, 17 Shandong Rd, Qingdao, Shandong, 266000, China
- Department of Physiology, Institute of Brain Sciences and Related Disorders, Qingdao University, 308 Ningxia Rd., Qingdao, Shandong, 266071, China
- Department of rehabilitation medicine, Affiliated Hospital of Qingdao University, 16 Jiangsu Rd., Qingdao, Shandong, 266000, China
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Tezenas-du-Montcel C, Tolle V. La régulation de la prise alimentaire au travers des actions antagonistes de la ghréline et du LEAP-2. CAHIERS DE NUTRITION ET DE DIÉTÉTIQUE 2023. [DOI: 10.1016/j.cnd.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Gross JD, Zhou Y, Barak LS, Caron MG. Ghrelin receptor signaling in health and disease: a biased view. Trends Endocrinol Metab 2023; 34:106-118. [PMID: 36567228 PMCID: PMC9852078 DOI: 10.1016/j.tem.2022.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/23/2022] [Accepted: 12/06/2022] [Indexed: 12/25/2022]
Abstract
As allosteric complexes, G-protein-coupled receptors (GPCRs) respond to extracellular stimuli and pleiotropically couple to intracellular transducers to elicit signaling pathway-dependent effects in a process known as biased signaling or functional selectivity. One such GPCR, the ghrelin receptor (GHSR1a), has a crucial role in restoring and maintaining metabolic homeostasis during disrupted energy balance. Thus, pharmacological modulation of GHSR1a bias could offer a promising strategy to treat several metabolism-based disorders. Here, we summarize current evidence supporting GHSR1a functional selectivity in vivo and highlight recent structural data. We propose that precise determinations of GHSR1a molecular pharmacology and pathway-specific physiological effects will enable discovery of GHSR1a drugs with tailored signaling profiles, thereby providing safer and more effective treatments for metabolic diseases.
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Affiliation(s)
- Joshua D Gross
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Yang Zhou
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Lawrence S Barak
- Department of Cell Biology, Duke University, Durham, NC 27710, USA.
| | - Marc G Caron
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
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Mustafá ER, McCarthy CI, Portales AE, Cordisco Gonzalez S, Rodríguez SS, Raingo J. Constitutive activity of the dopamine (D 5 ) receptor, highly expressed in CA1 hippocampal neurons, selectively reduces Ca V 3.2 and Ca V 3.3 currents. Br J Pharmacol 2022; 180:1210-1231. [PMID: 36480023 DOI: 10.1111/bph.16006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/31/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE CaV 3.1-3 currents differentially contribute to neuronal firing patterns. CaV 3 are regulated by G protein-coupled receptors (GPCRs) activity, but information about CaV 3 as targets of the constitutive activity of GPCRs is scarce. We investigate the impact of D5 recpetor constitutive activity, a GPCR with high levels of basal activity, on CaV 3 functionality. D5 recpetor and CaV 3 are expressed in the hippocampus and have been independently linked to pathophysiological states associated with epilepsy. EXPERIMENTAL APPROACH Our study models were HEK293T cells heterologously expressing D1 or D5 receptor and CaV 3.1-3, and mouse brain slices containing the hippocampus. We used chlorpromazine (D1 /D5 inverse agonist) and a D5 receptor mutant lacking constitutive activity as experimental tools. We measured CaV 3 currents and excitability parameters using the patch-clamp technique. We completed our study with computational modelling and imaging technique. KEY RESULTS We found a higher sensitivity to TTA-P2 (CaV 3 blocker) in CA1 pyramidal neurons obtained from chlorpromazine-treated animals compared with vehicle-treated animals. We found that CaV 3.2 and CaV 3.3-but not CaV 3.1-are targets of D5 receptor constitutive activity in HEK293T cells. Finally, we found an increased firing rate in CA1 pyramidal neurons from chlorpromazine-treated animals in comparison with vehicle-treated animals. Similar changes in firing rate were observed on a neuronal model with controlled CaV 3 currents levels. CONCLUSIONS AND IMPLICATIONS Native hippocampal CaV 3 and recombinant CaV 3.2-3 are sensitive to D5 receptor constitutive activity. Manipulation of D5 receptor constitutive activity could be a valuable strategy to control neuronal excitability, especially in exacerbated conditions such as epilepsy.
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Affiliation(s)
- Emilio Román Mustafá
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET), Scientific Research Commission of the Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], Buenos Aires, Argentina
| | - Clara Inés McCarthy
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET), Scientific Research Commission of the Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], Buenos Aires, Argentina
| | - Andrea Estefanía Portales
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET), Scientific Research Commission of the Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], Buenos Aires, Argentina
| | - Santiago Cordisco Gonzalez
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET), Scientific Research Commission of the Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], Buenos Aires, Argentina
| | - Silvia Susana Rodríguez
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET), Scientific Research Commission of the Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], Buenos Aires, Argentina
| | - Jesica Raingo
- Electrophysiology Laboratory of the Multidisciplinary Institute of Cell Biology [Argentine Research Council (CONICET), Scientific Research Commission of the Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], Buenos Aires, Argentina
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Hwang E, Scarlett JM, Baquero AF, Bennett CM, Dong Y, Chau D, Brown JM, Mercer AJ, Meek TH, Grove KL, Phan BAN, Morton GJ, Williams KW, Schwartz MW. Sustained inhibition of NPY/AgRP neuronal activity by FGF1. JCI Insight 2022; 7:e160891. [PMID: 35917179 PMCID: PMC9536267 DOI: 10.1172/jci.insight.160891] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
In rodent models of type 2 diabetes (T2D), central administration of FGF1 normalizes elevated blood glucose levels in a manner that is sustained for weeks or months. Increased activity of NPY/AgRP neurons in the hypothalamic arcuate nucleus (ARC) is implicated in the pathogenesis of hyperglycemia in these animals, and the ARC is a key brain area for the antidiabetic action of FGF1. We therefore sought to determine whether FGF1 inhibits NPY/AgRP neurons and, if so, whether this inhibitory effect is sufficiently durable to offer a feasible explanation for sustained diabetes remission induced by central administration of FGF1. Here, we show that FGF1 inhibited ARC NPY/AgRP neuron activity, both after intracerebroventricular injection in vivo and when applied ex vivo in a slice preparation; we also showed that the underlying mechanism involved increased input from presynaptic GABAergic neurons. Following central administration, the inhibitory effect of FGF1 on NPY/AgRP neurons was also highly durable, lasting for at least 2 weeks. To our knowledge, no precedent for such a prolonged inhibitory effect exists. Future studies are warranted to determine whether NPY/AgRP neuron inhibition contributes to the sustained antidiabetic action elicited by intracerebroventricular FGF1 injection in rodent models of T2D.
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Affiliation(s)
- Eunsang Hwang
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Jarrad M. Scarlett
- Department of Medicine, University of Washington Medicine Diabetes Institute, Seattle, Washington, USA
- Department of Pediatric Gastroenterology and Hepatology, Seattle Children’s Hospital, Seattle, Washington, USA
| | - Arian F. Baquero
- Obesity Research, Novo Nordisk Research Center Seattle, Seattle, Washington, USA
| | - Camdin M. Bennett
- Obesity Research, Novo Nordisk Research Center Seattle, Seattle, Washington, USA
| | - Yanbin Dong
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Dominic Chau
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Jenny M. Brown
- Department of Medicine, University of Washington Medicine Diabetes Institute, Seattle, Washington, USA
- University of Copenhagen, Novo Nordisk Foundation Center for Basic Metabolic Research, Copenhagen, Denmark
| | - Aaron J. Mercer
- Obesity Research, Novo Nordisk Research Center Seattle, Seattle, Washington, USA
| | - Thomas H. Meek
- Obesity Research, Novo Nordisk Research Center Seattle, Seattle, Washington, USA
- Discovery Technologies & Genomics, Novo Nordisk Research Centre Oxford, Oxford, United Kingdom
| | - Kevin L. Grove
- Obesity Research, Novo Nordisk Research Center Seattle, Seattle, Washington, USA
| | - Bao Anh N. Phan
- Department of Medicine, University of Washington Medicine Diabetes Institute, Seattle, Washington, USA
| | - Gregory J. Morton
- Department of Medicine, University of Washington Medicine Diabetes Institute, Seattle, Washington, USA
| | - Kevin W. Williams
- Department of Internal Medicine, Center for Hypothalamic Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Michael W. Schwartz
- Department of Medicine, University of Washington Medicine Diabetes Institute, Seattle, Washington, USA
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Binding domain characterization of growth hormone secretagogue receptor. J Transl Int Med 2022; 10:146-155. [PMID: 35959447 PMCID: PMC9328036 DOI: 10.2478/jtim-2022-0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background and Objectives Activation of ghrelin receptor growth hormone secretagogue receptor (GHS-R) by endogenous or synthetic ligands amplifies pulsatile release of growth hormone (GH) and enhances food intake, very relevant to development and growth. GHS-R is a G-protein coupled receptor that has great druggable potential. Understanding the precise ligand and receptor interactions is crucial to advance the application of GHS-R. Materials and Methods We used radiolabeled ligand-binding assay and growth hormone release assay to assess the binding and functional characteristics of GHS-R to synthetic agonists MK-0677 and GHS-25, as well as to endogenous peptide ligand ghrelin. We analyzed the ligand-dependent activity of GHS-R by measuring aequorin-based [Ca++]i responses. To define a ligand-binding pocket of GHS-R, we generated a series of human/puffer fish GHS-R chimeras by domain swapping, as well as a series of mutants by site-directed mutagenesis. Results We found that the synthetic ligands have high binding affinity to GHS-R in the in vitro competitive binding assay. Remarkably, the in vivo GH secretagogue activity is higher with the synthetic agonists MK-0677 and GHS-25 than that of ghrelin. Importantly, the activity was completely abolished in GHS-R knockout mice. In GHS-R chimera analysis, we identified the C-terminal region, particularly the transmembrane domain 6 (TM6), to be critical for the ligand-dependent activity. Our site-directed mutagenesis study further revealed that amino acid residues D99 and W276 in GHS-R are essential for ligand binding. Interestingly, critical residues distinctively interact with different ligands, MK-0677 activation depends on E124, while ghrelin and GHS-25 preferentially interact with F279. Conclusion The ligand-binding pocket of human GHS-R is mainly defined by interactive residues in TM6 and the adjacent region of the receptor. This novel finding in GHS-R binding domains advances the structural/ functional understanding of GHS-R, which will help to select/design better GHS-R agonists/ antagonists for future therapeutic applications.
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Péraldi-Roux S, Bayle M, M'Kadmi C, Damian M, Vaillé J, Fernandez G, Paula Cornejo M, Marie J, Banères JL, Ben Haj Salah K, Fehrentz JA, Cantel S, Perello M, Denoyelle S, Oiry C, Neasta J. Design and Characterization of a Triazole-Based Growth Hormone Secretagogue Receptor Modulator Inhibiting the Glucoregulatory and Feeding Actions of Ghrelin. Biochem Pharmacol 2022; 202:115114. [DOI: 10.1016/j.bcp.2022.115114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/26/2022] [Accepted: 05/26/2022] [Indexed: 11/02/2022]
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Han F, Xu F, Zhu Q, Sun P, Zhou Y, Yu M. Virus-mediated GHS-R1a expression in the basolateral amygdala blocks extinction of conditioned taste aversion memory in rats. Biochem Biophys Res Commun 2022; 602:57-62. [PMID: 35255434 DOI: 10.1016/j.bbrc.2022.02.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/26/2022] [Indexed: 11/28/2022]
Abstract
Ghrelin is an orexigenic gastric hormone that promotes feeding behaviors and regulating energy homeostasis in both humans and rodents. Our previous studies have shown that ghrelin, when locally infused into the basolateral amygdala (BLA), blocks both acquisition and extinction of conditioned taste aversion (CTA) memory in rats. In this study, we further investigated the effect of virus-mediated overexpression of ghrelin receptor growth hormone secretagogue receptor 1a (GHS-R1a) in BLA pyramidal neurons on CTA memory processes. We found that upregulation of GHS-R1a expression in BLA pyramidal neurons repressed CTA extinction while it had no effect on CTA acquisition. In addition, we reported that local infusion of the endogenous GHS-R1a antagonist, liver-expressed antimicrobial peptide 2 (LEAP2), in the BLA abolished the inhibitory effect of increased GHS-R1a on CTA memory extinction. Those findings provide new supportive evidence that ghrelin/GHS-R1a signaling in the BLA circuit shapes emotional memory processes.
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Affiliation(s)
- Fubing Han
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China; Department of Neurosurgery, Affiliated Hospital of Qingdao University, Qingdao, Shangdong, 266000, China
| | - Fenghua Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Qianqian Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - Peng Sun
- Department of Neurosurgery, Affiliated Hospital of Qingdao University, Qingdao, Shangdong, 266000, China
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China; Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, Shandong, 266071, China; Department of Rehabilitation Medicine, Affiliated Hospital of Qingdao University, Qingdao, Shangdong, 266000, China.
| | - Ming Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China.
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12
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GHS-R1a activity suppresses synaptic function of primary cultured hippocampal neurons. Biochem Biophys Res Commun 2022; 602:91-97. [DOI: 10.1016/j.bbrc.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/01/2022] [Indexed: 11/18/2022]
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13
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Wit JM, Joustra SD, Losekoot M, van Duyvenvoorde HA, de Bruin C. Differential Diagnosis of the Short IGF-I-Deficient Child with Apparently Normal Growth Hormone Secretion. Horm Res Paediatr 2022; 94:81-104. [PMID: 34091447 DOI: 10.1159/000516407] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 04/08/2021] [Indexed: 11/19/2022] Open
Abstract
The current differential diagnosis for a short child with low insulin-like growth factor I (IGF-I) and a normal growth hormone (GH) peak in a GH stimulation test (GHST), after exclusion of acquired causes, includes the following disorders: (1) a decreased spontaneous GH secretion in contrast to a normal stimulated GH peak ("GH neurosecretory dysfunction," GHND) and (2) genetic conditions with a normal GH sensitivity (e.g., pathogenic variants of GH1 or GHSR) and (3) GH insensitivity (GHI). We present a critical appraisal of the concept of GHND and the role of 12- or 24-h GH profiles in the selection of children for GH treatment. The mean 24-h GH concentration in healthy children overlaps with that in those with GH deficiency, indicating that the previously proposed cutoff limit (3.0-3.2 μg/L) is too high. The main advantage of performing a GH profile is that it prevents about 20% of false-positive test results of the GHST, while it also detects a low spontaneous GH secretion in children who would be considered GH sufficient based on a stimulation test. However, due to a considerable burden for patients and the health budget, GH profiles are only used in few centres. Regarding genetic causes, there is good evidence of the existence of Kowarski syndrome (due to GH1 variants) but less on the role of GHSR variants. Several genetic causes of (partial) GHI are known (GHR, STAT5B, STAT3, IGF1, IGFALS defects, and Noonan and 3M syndromes), some responding positively to GH therapy. In the final section, we speculate on hypothetical causes.
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Affiliation(s)
- Jan M Wit
- Department of Paediatrics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Sjoerd D Joustra
- Department of Paediatrics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Monique Losekoot
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Christiaan de Bruin
- Department of Paediatrics, Leiden University Medical Centre, Leiden, The Netherlands
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14
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Petersen N, Greiner TU, Torz L, Bookout A, Gerstenberg MK, Castorena CM, Kuhre RE. Targeting the Gut in Obesity: Signals from the Inner Surface. Metabolites 2022; 12:metabo12010039. [PMID: 35050161 PMCID: PMC8778595 DOI: 10.3390/metabo12010039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 12/26/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Obesity is caused by prolonged energy surplus. Current anti-obesity medications are mostly centralized around the energy input part of the energy balance equation by increasing satiety and reducing appetite. Our gastrointestinal tract is a key organ for regulation of food intake and supplies a tremendous number of circulating signals that modulate the activity of appetite-regulating areas of the brain by either direct interaction or through the vagus nerve. Intestinally derived messengers are manifold and include absorbed nutrients, microbial metabolites, gut hormones and other enterokines, collectively comprising a fine-tuned signalling system to the brain. After a meal, nutrients directly interact with appetite-inhibiting areas of the brain and induce satiety. However, overall feeding behaviour also depends on secretion of gut hormones produced by highly specialized and sensitive enteroendocrine cells. Moreover, circulating microbial metabolites and their interactions with enteroendocrine cells further contribute to the regulation of feeding patterns. Current therapies exploiting the appetite-regulating properties of the gut are based on chemically modified versions of the gut hormone, glucagon-like peptide-1 (GLP-1) or on inhibitors of the primary GLP-1 inactivating enzyme, dipeptidyl peptidase-4 (DPP-4). The effectiveness of these approaches shows that that the gut is a promising target for therapeutic interventions to achieve significant weigh loss. We believe that increasing understanding of the functionality of the intestinal epithelium and new delivery systems will help develop selective and safe gut-based therapeutic strategies for improved obesity treatment in the future. Here, we provide an overview of the major homeostatic appetite-regulating signals generated by the intestinal epithelial cells and how these signals may be harnessed to treat obesity by pharmacological means.
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Affiliation(s)
- Natalia Petersen
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Correspondence:
| | - Thomas U. Greiner
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Lola Torz
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Angie Bookout
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk Research Center, Seattle, WA 98109, USA; (A.B.); (C.M.C.)
| | - Marina Kjærgaard Gerstenberg
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
| | - Carlos M. Castorena
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk Research Center, Seattle, WA 98109, USA; (A.B.); (C.M.C.)
| | - Rune Ehrenreich Kuhre
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk A/S, Novo Park 1, 2670 Måløv, Denmark; (L.T.); (M.K.G.); (R.E.K.)
- Department of Veterinary and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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15
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Price ML, Ley CD, Gorvin CM. The emerging role of heterodimerisation and interacting proteins in ghrelin receptor function. J Endocrinol 2021; 252:R23-R39. [PMID: 34663757 PMCID: PMC8630777 DOI: 10.1530/joe-21-0206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 10/18/2021] [Indexed: 11/14/2022]
Abstract
Ghrelin is a peptide hormone secreted primarily by the stomach that acts upon the growth hormone secretagogue receptor (GHSR1), a G protein-coupled receptor whose functions include growth hormone secretion, appetite regulation, energy expenditure, regulation of adiposity, and insulin release. Following the discovery that GHSR1a stimulates food intake, receptor antagonists were developed as potential therapies to regulate appetite. However, despite reductions in signalling, the desired effects on appetite were absent. Studies in the past 15 years have demonstrated GHSR1a can interact with other transmembrane proteins, either by direct binding (i.e. heteromerisation) or via signalling cross-talk. These interactions have various effects on GHSR1a signalling including preferential coupling to one pathway (i.e. biased signalling), coupling to a unique G protein (G protein switching), suppression of GHSR1a signalling, and enhancement of signalling by both receptors. While many of these interactions have been shown in cells overexpressing the proteins of interest and remain to be verified in tissues, substantial evidence exists showing that GHSR1a and the dopamine receptor D1 (DRD1) form heteromers, which promote synaptic plasticity and formation of hippocampal memory. Additionally, a reduction in GHSR1a-DRD1 complexes in favour of establishment of GHSR1a-Aβ complexes correlates with Alzheimer's disease, indicating that GHSR1a heteromers may have pathological functions. Herein, we summarise the evidence published to date describing interactions between GHSR1a and transmembrane proteins, discuss the experimental strengths and limitations of these studies, describe the physiological evidence for each interaction, and address their potential as novel drug targets for appetite regulation, Alzheimer's disease, insulin secretion, and inflammation.
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Affiliation(s)
- Maria L Price
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
| | - Cameron D Ley
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
| | - Caroline M Gorvin
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, UK
- Correspondence should be addressed to C M Gorvin:
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16
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Liu T, Ji RL, Tao YX. Naturally occurring mutations in G protein-coupled receptors associated with obesity and type 2 diabetes mellitus. Pharmacol Ther 2021; 234:108044. [PMID: 34822948 DOI: 10.1016/j.pharmthera.2021.108044] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors involved in the regulation of almost all known physiological processes. Dysfunctions of GPCR-mediated signaling have been shown to cause various diseases. The prevalence of obesity and type 2 diabetes mellitus (T2DM), two strongly associated disorders, is increasing worldwide, with tremendous economical and health burden. New safer and more efficacious drugs are required for successful weight reduction and T2DM treatment. Multiple GPCRs are involved in the regulation of energy and glucose homeostasis. Mutations in these GPCRs contribute to the development and progression of obesity and T2DM. Therefore, these receptors can be therapeutic targets for obesity and T2DM. Indeed some of these receptors, such as melanocortin-4 receptor and glucagon-like peptide 1 receptor, have provided important new drugs for treating obesity and T2DM. This review will focus on the naturally occurring mutations of several GPCRs associated with obesity and T2DM, especially incorporating recent large genomic data and insights from structure-function studies, providing leads for future investigations.
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Affiliation(s)
- Ting Liu
- Department of Anatomy, Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL 36849, United States
| | - Ren-Lei Ji
- Department of Anatomy, Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL 36849, United States
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL 36849, United States.
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17
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Peris-Sampedro F, Le May MV, Stoltenborg I, Schéle E, Dickson SL. A skeleton in the cupboard in ghrelin research: Where are the skinny dwarfs? J Neuroendocrinol 2021; 33:e13025. [PMID: 34427011 DOI: 10.1111/jne.13025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/09/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022]
Abstract
Based on studies delivering ghrelin or ghrelin receptor agonists, we have learned a great deal about the importance of the brain ghrelin signalling system for a wide range of physiological processes that include feeding behaviours, growth hormone secretion and glucose homeostasis. Because these processes can be considered as essential to life, the question arises as to why mouse models of depleted ghrelin signalling are not all skinny dwarfs with a host of behavioural and metabolic problems. Here, we provide a systematic detailed review of the phenotype of mice with deficient ghrelin signalling to help better understand the relevance and importance of the brain ghrelin signalling system, with a particular emphasis on those questions that remain unanswered.
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Affiliation(s)
- Fiona Peris-Sampedro
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Schéle
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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18
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Li N, Li N, Xu F, Yu M, Qiao Z, Zhou Y. Selectively increasing GHS-R1a expression in dCA1 excitatory/inhibitory neurons have opposite effects on memory encoding. Mol Brain 2021; 14:157. [PMID: 34641940 PMCID: PMC8513281 DOI: 10.1186/s13041-021-00866-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/04/2021] [Indexed: 11/20/2022] Open
Abstract
Aim Growth hormone secretagogue receptor 1a (GHS-R1a) is widely distributed in brain including the hippocampus. Studies have demonstrated the critical role of hippocampal ghrelin/GHS-R1a signaling in synaptic physiology, memory and cognitive dysfunction associated with Alzheimer’s disease (AD). However, current reports are inconsistent, and the mechanism underlying memory modulation of GHS-R1a signaling is uncertain. In this study, we aim to investigate the direct impact of selective increase of GHS-R1a expression in dCA1 excitatory/inhibitory neurons on learning and memory. Methods Endogenous GHS-R1a distribution in dCA1 excitatory/inhibitory neurons was assessed by fluorescence in situ hybridization. Cre-dependent GHS-R1a overexpression in excitatory or inhibitory neurons was done by stereotaxic injection of aav-hSyn-DIO-hGhsr1a-2A-eGFP virus in dCA1 region of vGlut1-Cre or Dlx5/6-Cre mice respectively. Virus-mediated GHS-R1a upregulation in dCA1 neurons was confirmed by quantitative RT-PCR. Different behavioral paradigms were used to evaluate long-term memory performance. Results GHS-R1a is distributed both in dCA1 excitatory pyramidal neurons (αCaMKII+) and in inhibitory interneurons (GAD67+). Selective increase of GHS-R1a expression in dCA1 pyramidal neurons impaired spatial memory and object-place recognition memory. In contrast, selective increase of GHS-R1a expression in dCA1 interneurons enhanced long-term memory performance. Our findings reveal, for the first time, a neuronal type-specific role that hippocampal GHS-R1a signaling plays in regulating memory. Therefore, manipulating GHS-R1a expression/activity in different subpopulation of neurons may help to clarify current contradictory findings and to elucidate mechanism of memory control by ghrelin/GHS-R1a signaling, under both physiological and pathological conditions such as AD. Supplementary Information The online version contains supplementary material available at 10.1186/s13041-021-00866-8.
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Affiliation(s)
- Nan Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, 266071, Shandong, China
| | - Na Li
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, 266071, Shandong, China
| | - Fenghua Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, 266071, Shandong, China
| | - Ming Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, 266071, Shandong, China
| | - Zichen Qiao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, 266071, Shandong, China
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, 266071, Shandong, China. .,Institute of Brain Sciences and Related Disorders, Qingdao University, Qingdao, 266071, Shandong, China. .,Department of Rehabilitation Medicine, Affiliated Hospital of Qingdao University, Qingdao, 266000, Shangdong, China.
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19
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Peris-Sampedro F, Stoltenborg I, Le May MV, Zigman JM, Adan RAH, Dickson SL. Genetic deletion of the ghrelin receptor (GHSR) impairs growth and blunts endocrine response to fasting in Ghsr-IRES-Cre mice. Mol Metab 2021; 51:101223. [PMID: 33798772 PMCID: PMC8102639 DOI: 10.1016/j.molmet.2021.101223] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE The orexigenic hormone ghrelin exerts its physiological effects by binding to and activating the growth hormone secretagogue receptor (GHSR). The recent development of a Ghsr-IRES-Cre knock-in mouse line has enabled to genetically access GHSR-expressing neurons. Inserting a Cre construct using a knock-in strategy, even when following an upstream internal ribosome entry site (IRES) can, however, interfere with expression of a targeted gene, with consequences for the phenotype emerging. This study aimed to phenotype, both physically and metabolically, heterozygous and homozygous Ghsr-IRES-Cre mice, with a view to discovering the extent to which the ghrelin signalling system remains functional in these mice. METHODS We assessed feeding and arcuate nucleus (Arc) Fos activation in wild-type, heterozygous and homozygous Ghsr-IRES-Cre mice in response to peripherally-administered ghrelin. We also characterised their developmental and growth phenotypes, as well as their metabolic responses upon an overnight fast. RESULTS Insertion of the IRES-Cre cassette into the 3'-untranslated region of the Ghsr gene led to a gene-dosage GHSR depletion in the Arc. Whereas heterozygotes remained ghrelin-responsive and more closely resembled wild-types, ghrelin had reduced orexigenic efficacy and failed to induce Arc Fos expression in homozygous littermates. Homozygotes had a lower body weight accompanied by a shorter body length, less fat tissue content, altered bone parameters, and lower insulin-like growth factor-1 levels compared to wild-type and heterozygous littermates. Moreover, both heterozygous and homozygous Ghsr-IRES-Cre mice lacked the usual fasting-induced rise in growth hormone (GH) and displayed an exaggerated drop in blood glucose and insulin compared to wild-types. Unexpectedly, fasting acyl-ghrelin levels were allele-dependently increased. CONCLUSIONS Our data suggest that (i) heterozygous but not homozygous Ghsr-IRES-Cre mice retain the usual responsiveness to administered ghrelin, (ii) the impact of fasting on GH release and glucose homeostasis is altered even when only one copy of the Ghsr gene is non-functional (as in heterozygous Ghsr-IRES-Cre mice) and (iii) homozygous Ghsr-IRES-Cre mice exhibit growth retardation. Of the many transgenic models of suppressed ghrelin signalling, Ghsr-IRES-Cre mice emerge as best representing the full breadth of the expected phenotype with respect to body weight, growth, and metabolic parameters.
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Affiliation(s)
- Fiona Peris-Sampedro
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Jeffrey M Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA
| | - Roger A H Adan
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; Department of Translational Neuroscience, UMC Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Suzanne L Dickson
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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20
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Mustafá ER, Cordisco González S, Damian M, Cantel S, Denoyelle S, Wagner R, Schiöth HB, Fehrentz JA, Banères JL, Perelló M, Raingo J. LEAP2 Impairs the Capability of the Growth Hormone Secretagogue Receptor to Regulate the Dopamine 2 Receptor Signaling. Front Pharmacol 2021; 12:712437. [PMID: 34447311 PMCID: PMC8383165 DOI: 10.3389/fphar.2021.712437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/26/2021] [Indexed: 12/12/2022] Open
Abstract
The growth hormone secretagogue receptor (GHSR) signals in response to ghrelin, but also acts via ligand-independent mechanisms that include either constitutive activation or interaction with other G protein-coupled receptors, such as the dopamine 2 receptor (D2R). A key target of GHSR in neurons is voltage-gated calcium channels type 2.2 (CaV2.2). Recently, the liver-expressed antimicrobial peptide 2 (LEAP2) was recognized as a novel GHSR ligand, but the mechanism of action of LEAP2 on GHSR is not well understood. Here, we investigated the role of LEAP2 on the canonical and non-canonical modes of action of GHSR on CaV2.2 function. Using a heterologous expression system and patch-clamp recordings, we found that LEAP2 impairs the reduction of CaV2.2 currents induced by ghrelin-evoked and constitutive GHSR activities, acting as a GHSR antagonist and inverse agonist, respectively. We also found that LEAP2 prevents GHSR from modulating the effects of D2R signaling on CaV2.2 currents, and that the GHSR-binding N-terminal region LEAP2 underlies these effects. Using purified labeled receptors assembled into lipid nanodiscs and Forster Resonance Energy Transfer (FRET) assessments, we found that the N-terminal region of LEAP2 stabilizes an inactive conformation of GHSR that is dissociated from Gq protein and, consequently, reverses the effect of GHSR on D2R-dependent Gi activation. Thus, our results provide critical molecular insights into the mechanism mediating LEAP2 modulation of GHSR.
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Affiliation(s)
- Emilio R Mustafá
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata (UNLP)], La Plata, Argentina
| | - Santiago Cordisco González
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata (UNLP)], La Plata, Argentina
| | - Marjorie Damian
- Institut des Biomolécules Max Mousseron (IBMM), Université Montpellier, CNRS, Montpellier, France
| | - Sonia Cantel
- Institut des Biomolécules Max Mousseron (IBMM), Université Montpellier, CNRS, Montpellier, France
| | - Severine Denoyelle
- Institut des Biomolécules Max Mousseron (IBMM), Université Montpellier, CNRS, Montpellier, France
| | - Renaud Wagner
- Plateforme IMPReSs, CNRS UMR7242, Biotechnologie et Signalisation Cellulaire, École Supérieure de Biotechnologie de Strasbourg, Strasbourg, France
| | - Helgi B Schiöth
- Department of Neuroscience, Uppsala University, Uppsala, Sweden.,Institute for Translational Medicine and Biothechnology, I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Jean-Alain Fehrentz
- Institut des Biomolécules Max Mousseron (IBMM), Université Montpellier, CNRS, Montpellier, France
| | - Jean-Louis Banères
- Institut des Biomolécules Max Mousseron (IBMM), Université Montpellier, CNRS, Montpellier, France
| | - Mario Perelló
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata (UNLP)], La Plata, Argentina
| | - Jesica Raingo
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata (UNLP)], La Plata, Argentina
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21
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Shankar K, Metzger NP, Singh O, Mani BK, Osborne-Lawrence S, Varshney S, Gupta D, Ogden SB, Takemi S, Richard CP, Nandy K, Liu C, Zigman JM. LEAP2 deletion in mice enhances ghrelin's actions as an orexigen and growth hormone secretagogue. Mol Metab 2021; 53:101327. [PMID: 34428557 PMCID: PMC8452786 DOI: 10.1016/j.molmet.2021.101327] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 02/03/2023] Open
Abstract
Objective The hormone liver-expressed antimicrobial peptide-2 (LEAP2) is a recently identified antagonist and an inverse agonist of the growth hormone secretagogue receptor (GHSR). GHSR's other well-known endogenous ligand, acyl-ghrelin, increases food intake, body weight, and GH secretion and is lowered in obesity but elevated upon fasting. In contrast, LEAP2 reduces acyl-ghrelin-induced food intake and GH secretion and is found elevated in obesity but lowered upon fasting. Thus, the plasma LEAP2/acyl-ghrelin molar ratio could be a key determinant modulating GHSR signaling in response to changes in body mass and feeding status. In particular, LEAP2 may serve to dampen acyl-ghrelin action in the setting of obesity, which is associated with ghrelin resistance. Here, we sought to determine the metabolic effects of genetic LEAP2 deletion. Methods We generated the first known LEAP2-KO mouse line. Food intake, GH secretion, and cellular activation (c-fos induction) in different brain regions following s.c. acyl-ghrelin administration in LEAP2-KO mice and wild-type littermates were determined. LEAP2-KO mice and wild-type littermates were submitted to a battery of tests (such as measurements of body weight, food intake, and body composition; indirect calorimetry, determination of locomotor activity, and meal patterning while housed in metabolic cages) over the course of 16 weeks of high-fat diet and/or standard chow feeding. Fat accumulation was assessed in hematoxylin & eosin-stained and oil red O-stained liver sections from these mice. Results LEAP2-KO mice were more sensitive to s.c. ghrelin. In particular, acyl-ghrelin acutely stimulated food intake at a dose of 0.5 mg/kg BW in standard chow-fed LEAP2-KO mice while a 2× higher dose was required by wild-type littermates. Also, acyl-ghrelin stimulated food intake at a dose of 1 mg/kg BW in high-fat diet-fed LEAP2-KO mice while not even a 10× higher dose was effective in wild-type littermates. Acyl-ghrelin induced a 90.9% higher plasma GH level and 77.2–119.7% higher numbers of c-fos-immunoreactive cells in the arcuate nucleus and olfactory bulb, respectively, in LEAP2-KO mice than in wild-type littermates. LEAP2 deletion raised body weight (by 15.0%), food intake (by 18.4%), lean mass (by 6.1%), hepatic fat (by 42.1%), and body length (by 1.7%) in females on long-term high-fat diet as compared to wild-type littermates. After only 4 weeks on the high-fat diet, female LEAP2-KO mice exhibited lower O2 consumption (by 13%), heat production (by 9.5%), and locomotor activity (by 49%) than by wild-type littermates during the first part of the dark period. These genotype-dependent differences were not observed in high-fat diet-exposed males or female and male mice exposed for long term to standard chow diet. Conclusions LEAP2 deletion sensitizes lean and obese mice to the acute effects of administered acyl-ghrelin on food intake and GH secretion. LEAP2 deletion increases body weight in females chronically fed a high-fat diet as a result of lowered energy expenditure, reduced locomotor activity, and increased food intake. Furthermore, in female mice, LEAP2 deletion increases body length and exaggerates the hepatic fat accumulation normally associated with chronic high-fat diet feeding. A novel line of LEAP2-knockout mice was generated. LEAP2 deletion sensitizes mice to the GH secretory effects of administered ghrelin. LEAP2 deletion reduces ghrelin resistance in diet-induced obese mice. HFD-fed female LEAP2-KO mice eat more and gain more body weight and hepatic fat. HFD-fed female LEAP2-KO mice exhibit lowered energy expenditure and activity.
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Affiliation(s)
- Kripa Shankar
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Nathan P Metzger
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Omprakash Singh
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Bharath K Mani
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Salil Varshney
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Deepali Gupta
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sean B Ogden
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Shota Takemi
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Corine P Richard
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Karabi Nandy
- Division of Biostatistics, Department of Population and Data Sciences, UT Southwestern Medical Center, Dallas, TX, USA
| | - Chen Liu
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA.
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22
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Lewiński A, Karbownik-Lewińska M, Wieczorek-Szukała K, Stasiak M, Stawerska R. Contribution of Ghrelin to the Pathogenesis of Growth Hormone Deficiency. Int J Mol Sci 2021; 22:9066. [PMID: 34445772 PMCID: PMC8396656 DOI: 10.3390/ijms22169066] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 02/07/2023] Open
Abstract
In this review we described the interactions between ghrelin and the growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis in children and adults with growth hormone deficiency (GHD). A possible involvement of these interactions in the pathogenesis of unexplained cases of GHD was suggested. Current research provides more and more details to the knowledge on the circadian rhythm of ghrelin. We gathered reports on the decreasing effect of Helicobacter pylori-related chronic gastritis on the number of ghrelin immunopositive cells and the consequent decrease in ghrelin serum concentration. The gastrointestinal tract microflora modification of the ghrelin action, by the mechanism of molecular mimicry, was also stressed. Moreover, the mutual relationships between ghrelin and the TSH-FT4/FT3 axis in growth and metabolic processes are described. It is to be recalled that FT4 and FT3 exert a permissive impact on IGF-1 action and, in turn, GH, in reaction mediated by IGF-1, enhances the monodeiodination of FT4 to FT3. Finally, we discussed the latest attempts to use the GH secretagogue receptor (GHS-R) analogues for possible diagnostic and therapeutic purposes.
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Affiliation(s)
- Andrzej Lewiński
- Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, 93-338 Lodz, Poland;
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
| | - Małgorzata Karbownik-Lewińska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
- Department of Oncological Endocrinology, Medical University of Lodz, 90-419 Lodz, Poland
| | | | - Magdalena Stasiak
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
| | - Renata Stawerska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
- Department of Paediatric Endocrinology, Medical University of Lodz, 90-419 Lodz, Poland
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23
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Gupta D, Patterson AM, Osborne-Lawrence S, Bookout AL, Varshney S, Shankar K, Singh O, Metzger NP, Richard CP, Wyler SC, Elmquist JK, Zigman JM. Disrupting the ghrelin-growth hormone axis limits ghrelin's orexigenic but not glucoregulatory actions. Mol Metab 2021; 53:101258. [PMID: 34023483 PMCID: PMC8203846 DOI: 10.1016/j.molmet.2021.101258] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/26/2021] [Accepted: 05/14/2021] [Indexed: 12/19/2022] Open
Abstract
Objective Acyl-ghrelin regulates eating, body weight, blood glucose, and GH secretion upon binding to its receptor GHSR (growth hormone secretagogue receptor; ghrelin receptor). GHSR is distributed in several brain regions and some peripheral cell-types including pituitary somatotrophs. The objective of the current study was to determine the functional significance of acyl-ghrelin's action on GHSR-expressing somatotrophs in mediating GH secretion and several of acyl-ghrelin's metabolic actions. Methods GH-IRES-Cre mice and loxP-flanked (floxed) GHSR mice were newly developed and then crossed to one another to generate mice that lacked GHSR selectively from somatotrophs. Following validation of mice with somatotroph-selective GHSR deletion, metabolic responses of these mice and control littermates were assessed following both acute and chronic acyl-ghrelin administration, a 24-h fast, and a prolonged 60% chronic caloric restriction protocol modeling starvation. Results In mice with somatotroph-selective GHSR deletion, a single peripheral injection of acyl-ghrelin failed to induce GH secretion or increase food intake, unlike wild-type and other littermate control groups. However, the usual acute blood glucose increase in response to the acyl-ghrelin bolus was preserved. Similarly, chronic s.c. acyl-ghrelin administration to mice with somatotroph-selective GHSR deletion failed to increase plasma GH, food intake, or body weight. Physiologically elevating plasma acyl-ghrelin via a 24-h fast also failed to raise plasma GH and resulted in a limited hyperphagic response upon food reintroduction in mice with somatotroph-selective GHSR deletion, although those mice nonetheless did not exhibit an exaggerated reduction in blood glucose. Physiologically elevating plasma acyl-ghrelin via a 15-day caloric restriction protocol which provided only 40% of usual daily calories failed to raise plasma GH in mice with somatotroph-selective GHSR deletion, although those mice did not exhibit life-threatening hypoglycemia. Conclusions These results reveal that direct engagement of GHSR-expressing somatotrophs is required for a peripheral ghrelin bolus to acutely stimulate GH secretion and the actions of chronic acyl-ghrelin delivery and physiological plasma acyl-ghrelin elevations to increase plasma GH. These results also suggest that actions of acyl-ghrelin to increase food intake and body weight are reliant on direct activation of GHSRs expressed on somatotrophs. Furthermore, these results suggest that the glucoregulatory actions of acyl-ghrelin – in particular, its actions to raise blood glucose when acutely administered, prevent small blood glucose drops following a 24-h fast, and avert life-threatening hypoglycemia during an acute-on-chronic caloric restriction protocol – do not depend on GHSR expression by somatotrophs. Mice with pituitary somatotroph-selective GHSR deletion were generated. Somatotroph-expressed GHSRs mediate GH secretion and food intake after acute ghrelin. Body weight effects of chronic ghrelin infusion require somatotroph-expressed GHSRs. Somatotroph-expressed GHSRs enable GH to increase upon chronic caloric restriction. Mice lacking somatotroph GHSRs maintain euglycemia upon chronic caloric restriction.
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Affiliation(s)
- Deepali Gupta
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Anna M Patterson
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Angie L Bookout
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Salil Varshney
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Kripa Shankar
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Omprakash Singh
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Nathan P Metzger
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Corine P Richard
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven C Wyler
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Joel K Elmquist
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey M Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA; Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA.
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24
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Ribeiro LF, Catarino T, Carvalho M, Cortes L, Santos SD, Opazo PO, Ribeiro LR, Oliveiros B, Choquet D, Esteban JA, Peça J, Carvalho AL. Ligand-independent activity of the ghrelin receptor modulates AMPA receptor trafficking and supports memory formation. Sci Signal 2021; 14:14/670/eabb1953. [PMID: 33593997 DOI: 10.1126/scisignal.abb1953] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The biological signals of hunger, satiety, and memory are interconnected. The role of the hormone ghrelin in regulating feeding and memory makes ghrelin receptors attractive targets for associated disorders. We investigated the effects of the high ligand-independent activity of the ghrelin receptor GHS-R1a on the physiology of excitatory synapses in the hippocampus. Blocking this activity produced a decrease in the synaptic content of AMPA receptors in hippocampal neurons and a reduction in GluA1 phosphorylation at Ser845 Reducing the ligand-independent activity of GHS-R1a increased the surface diffusion of AMPA receptors and impaired AMPA receptor-dependent synaptic delivery induced by chemical long-term potentiation. Accordingly, we found that blocking this GHS-R1a activity impaired spatial and recognition memory in mice. These observations support a role for the ligand-independent activity of GHS-R1a in regulating AMPA receptor trafficking under basal conditions and in the context of synaptic plasticity that underlies learning.
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Affiliation(s)
- Luís F Ribeiro
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.
| | - Tatiana Catarino
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,University of Coimbra, IIIUC-Institute for Interdisciplinary Research, 3030-789 Coimbra, Portugal
| | - Mário Carvalho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,MIT-Portugal Bioengineering Systems Doctoral Program, NOVA University of Lisbon, 1099-85, Lisboa, Portugal
| | - Luísa Cortes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,University of Coimbra, IIIUC-Institute for Interdisciplinary Research, 3030-789 Coimbra, Portugal
| | - Sandra D Santos
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,University of Coimbra, IIIUC-Institute for Interdisciplinary Research, 3030-789 Coimbra, Portugal
| | - Patricio O Opazo
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France.,CNRS, UMR 5297, 33000 Bordeaux, France
| | - Lyn Rosenbrier Ribeiro
- Functional and Mechanistic Safety, Clinical Pharmacology and Safety Sciences, R&D AstraZeneca, Cambridge CB2 0SL, UK
| | - Bárbara Oliveiros
- Laboratory of Biostatistics and Medical Informatics (LBIM), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal.,Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Daniel Choquet
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France.,CNRS, UMR 5297, 33000 Bordeaux, France.,Bordeaux Imaging Center, UMS 3420, CNRS-Bordeaux University, US4 INSERM, 33000 Bordeaux, France
| | - José A Esteban
- Department of Molecular Neurobiology, Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - João Peça
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,University of Coimbra, Department of Life Sciences, 3000-456 Coimbra, Portugal
| | - Ana Luísa Carvalho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal. .,University of Coimbra, Department of Life Sciences, 3000-456 Coimbra, Portugal
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25
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Cornejo MP, Mustafá ER, Cassano D, Banères JL, Raingo J, Perello M. The ups and downs of growth hormone secretagogue receptor signaling. FEBS J 2021; 288:7213-7229. [PMID: 33460513 DOI: 10.1111/febs.15718] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/05/2021] [Accepted: 01/14/2021] [Indexed: 12/14/2022]
Abstract
The growth hormone secretagogue receptor (GHSR) has emerged as one of the most fascinating molecules from the perspective of neuroendocrine control. GHSR is mainly expressed in the pituitary and the brain, and plays key roles regulating not only growth hormone secretion but also food intake, adiposity, body weight, glucose homeostasis and other complex functions. Quite atypically, GHSR signaling displays a basal constitutive activity that can be up- or downregulated by two digestive system-derived hormones: the octanoylated-peptide ghrelin and the liver-expressed antimicrobial peptide 2 (LEAP2), which was recently recognized as an endogenous GHSR ligand. The existence of two ligands with contrary actions indicates that GHSR activity can be tightly regulated and that the receptor displays the capability to integrate such opposing inputs in order to provide a balanced intracellular signal. This article provides a summary of the current understanding of the biology of ghrelin, LEAP2 and GHSR and discusses the reconceptualization of the cellular and physiological implications of the ligand-regulated GHSR signaling, based on the latest findings.
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Affiliation(s)
- María P Cornejo
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Emilio R Mustafá
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Daniela Cassano
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Jean-Louis Banères
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Montpellier cedex 5, France
| | - Jesica Raingo
- Laboratory of Electrophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], Buenos Aires, Argentina
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26
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Xiao X, Bi M, Jiao Q, Chen X, Du X, Jiang H. A new understanding of GHSR1a--independent of ghrelin activation. Ageing Res Rev 2020; 64:101187. [PMID: 33007437 DOI: 10.1016/j.arr.2020.101187] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/13/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
Growth hormone secretagogue receptor 1a (GHSR1a), a member of the G protein-coupled receptor (GPCR) family, is a functional receptor of ghrelin. The expression levels and activities of GHSR1a are affected by various factors. In past years, it has been found that the ghrelin-GHSR1a system can perform biological functions such as anti-inflammation, anti-apoptosis, and anti-oxidative stress. In addition to mediating the effect of ghrelin, GHSR1a also has abnormally high constitutive activity; that is, it can still transmit intracellular signals without activation of the ghrelin ligand. This constitutive activity affects brain functions, growth and development of the body; therefore, it has profound impacts on neurodegenerative diseases and some other age-related diseases. In addition, GHSR1a can also form homodimers or heterodimers with other GPCRs, affecting the release of neurotransmitters, appetite regulation, cell proliferation and insulin release. Therefore, further understanding of the constitutive activities and dimerization of GHSR1a will enable us to better clarify the characteristics of GHSR1a and provide more therapeutic targets for drug development. Here, we focus on the roles of GHSR1a in various biological functions and provide a comprehensive summary of the current research on GHSR1a to provide broader therapeutic prospects for age-related disease treatment.
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Affiliation(s)
- Xue Xiao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Mingxia Bi
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Qian Jiao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xi Chen
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xixun Du
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China.
| | - Hong Jiang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China.
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27
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"A LEAP 2 conclusions? Targeting the ghrelin system to treat obesity and diabetes". Mol Metab 2020; 46:101128. [PMID: 33246141 PMCID: PMC8085568 DOI: 10.1016/j.molmet.2020.101128] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 11/15/2020] [Accepted: 11/20/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND The hormone ghrelin stimulates food intake, promotes adiposity, increases body weight, and elevates blood glucose. Consequently, alterations in plasma ghrelin levels and the functioning of other components of the broader ghrelin system have been proposed as potential contributors to obesity and diabetes. Furthermore, targeting the ghrelin system has been proposed as a novel therapeutic strategy for obesity and diabetes. SCOPE OF REVIEW The current review focuses on the potential for targeting ghrelin and other proteins comprising the ghrelin system as a treatment for obesity and diabetes. The main components of the ghrelin system are introduced. Data supporting a role for the endogenous ghrelin system in the development of obesity and diabetes along with data that seemingly refute such a role are outlined. An argument for further research into the development of ghrelin system-targeted therapeutic agents is delineated. Also, an evidence-based discussion of potential factors and contexts that might influence the efficacy of this class of therapeutics is provided. MAJOR CONCLUSIONS It would not be a "leap to" conclusions to suggest that agents which target the ghrelin system - including those that lower acyl-ghrelin levels, raise LEAP2 levels, block GHSR activity, and/or raise desacyl-ghrelin signaling - could represent efficacious novel treatments for obesity and diabetes.
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28
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Goswami C, Dezaki K, Wang L, Inui A, Seino Y, Yada T. Ninjin'yoeito Targets Distinct Ca 2+ Channels to Activate Ghrelin-Responsive vs. Unresponsive NPY Neurons in the Arcuate Nucleus. Front Nutr 2020; 7:104. [PMID: 32766273 PMCID: PMC7379896 DOI: 10.3389/fnut.2020.00104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/08/2020] [Indexed: 12/22/2022] Open
Abstract
Appetite loss or anorexia substantially deteriorates quality of life in various diseases, and stand upstream of frailty. Neuropeptide Y (NPY) in the hypothalamic arcuate nucleus (ARC) and ghrelin released from stomach are potent inducers of appetite. We previously reported that Ninjin'yoeito, a Japanese kampo medicine comprising twelve herbs, restores food intake, and body weight in cisplatin-treated anorectic mice. Furthermore, Ninjin'yoeito increased cytosolic Ca2+ concentration ([Ca2+]i) in not only ghrelin-responsive but ghrelin-unresponsive NPY neurons in ARC. The cellular lineage/differentiation of ghrelin-unresponsive neuron is less defined but might alter along with aging and diet. This study examined the occupancy of ghrelin-unresponsive neurons among ARC NPY neurons in adult mice fed normal chow, and explored the mechanisms underlying Ninjin'yoeito-induced [Ca2+]i increases in ghrelin-unresponsive vs. ghrelin-responsive NPY neurons. Single ARC neurons were subjected to [Ca2+]i measurement and subsequent immunostaining for NPY. Ghrelin failed to increase [Ca2+]i in 42% of ARC NPY neurons. Ninjin'yoeito (10 μg/ml)-induced increases in [Ca2+]i were abolished in Ca2+ free condition in ghrelin-responsive and ghrelin-unresponsive ARC NPY neurons. Ninjin'yoeito-induced [Ca2+]i increases were inhibited by N-type Ca2+ channel blocker ω-conotoxin in the majority (17 of 20), while by L-type Ca2+ channel blocker nitrendipine in the minority (2 of 23), of ghrelin-responsive neurons. In contrast, Ninjin'yoeito-induced [Ca2+]i increases were inhibited by nitrendipine in the majority (14 of 17), while by ω-conotoxin in the minority (8 of 24), of ghrelin-unresponsive neurons. These results indicate that ghrelin-unresponsive neurons occur substantially among NPY neurons of ARC in adult mice fed normal chow. Ninjin'yoeito preferentially target N-type and L-type Ca2+ channels in the majority of ghrelin-responsive and ghrelin-unresponsive neurons, respectively, to increase [Ca2+]i. We suggest ARC N- and L-type Ca2+ channels as potential targets for activating, respectively, ghrelin-responsive, and unresponsive NPY neurons to treat anorexia.
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Affiliation(s)
- Chayon Goswami
- Division of Integrative Physiology, Center for Integrative Physiology, Kansai Electric Power Medical Research Institute, Kobe, Japan.,Division of Diabetes, Metabolism and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan.,Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Tochigi, Japan.,Department of Biochemistry and Molecular Biology, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Katsuya Dezaki
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Tochigi, Japan.,Faculty of Pharmacy, Iryo Sosei University, Iwaki, Japan
| | - Lei Wang
- Division of Integrative Physiology, Center for Integrative Physiology, Kansai Electric Power Medical Research Institute, Kobe, Japan.,Division of Diabetes, Metabolism and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan.,Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Tochigi, Japan
| | - Akio Inui
- Pharmacological Department of Herbal Medicine, Kagoshima University Graduate School of Medical & Dental Sciences, Kagoshima, Japan
| | - Yutaka Seino
- Division of Integrative Physiology, Center for Integrative Physiology, Kansai Electric Power Medical Research Institute, Kobe, Japan.,Center for Diabetes Research, Division of Diabetes and Endocrinology, Kansai Electric Power Medical Research Institute, Kobe, Japan
| | - Toshihiko Yada
- Division of Integrative Physiology, Center for Integrative Physiology, Kansai Electric Power Medical Research Institute, Kobe, Japan.,Division of Diabetes, Metabolism and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan.,Division of Integrative Physiology, Department of Physiology, Jichi Medical University School of Medicine, Tochigi, Japan.,Pharmacological Department of Herbal Medicine, Kagoshima University Graduate School of Medical & Dental Sciences, Kagoshima, Japan
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