1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Zhao BH, Ruze A, Zhao L, Li QL, Tang J, Xiefukaiti N, Gai MT, Deng AX, Shan XF, Gao XM. The role and mechanisms of microvascular damage in the ischemic myocardium. Cell Mol Life Sci 2023; 80:341. [PMID: 37898977 PMCID: PMC11073328 DOI: 10.1007/s00018-023-04998-z] [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: 05/22/2023] [Revised: 09/08/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023]
Abstract
Following myocardial ischemic injury, the most effective clinical intervention is timely restoration of blood perfusion to ischemic but viable myocardium to reduce irreversible myocardial necrosis, limit infarct size, and prevent cardiac insufficiency. However, reperfusion itself may exacerbate cell death and myocardial injury, a process commonly referred to as ischemia/reperfusion (I/R) injury, which primarily involves cardiomyocytes and cardiac microvascular endothelial cells (CMECs) and is characterized by myocardial stunning, microvascular damage (MVD), reperfusion arrhythmia, and lethal reperfusion injury. MVD caused by I/R has been a neglected problem compared to myocardial injury. Clinically, the incidence of microvascular angina and/or no-reflow due to ineffective coronary perfusion accounts for 5-50% in patients after acute revascularization. MVD limiting drug diffusion into injured myocardium, is strongly associated with the development of heart failure. CMECs account for > 60% of the cardiac cellular components, and their role in myocardial I/R injury cannot be ignored. There are many studies on microvascular obstruction, but few studies on microvascular leakage, which may be mainly due to the lack of corresponding detection methods. In this review, we summarize the clinical manifestations, related mechanisms of MVD during myocardial I/R, laboratory and clinical examination means, as well as the research progress on potential therapies for MVD in recent years. Better understanding the characteristics and risk factors of MVD in patients after hemodynamic reconstruction is of great significance for managing MVD, preventing heart failure and improving patient prognosis.
Collapse
Affiliation(s)
- Bang-Hao Zhao
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Amanguli Ruze
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Ling Zhao
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Qiu-Lin Li
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Jing Tang
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Nilupaer Xiefukaiti
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Min-Tao Gai
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - An-Xia Deng
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Xue-Feng Shan
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Xiao-Ming Gao
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China.
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China.
| |
Collapse
|
3
|
Tian J, Guo L, Wang T, Jia K, Swerdlow RH, Zigman JM, Du H. Liver-expressed antimicrobial peptide 2 elevation contributes to age-associated cognitive decline. JCI Insight 2023; 8:166175. [PMID: 37212281 DOI: 10.1172/jci.insight.166175] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 03/31/2023] [Indexed: 05/23/2023] Open
Abstract
Elderly individuals frequently report cognitive decline, while various studies indicate hippocampal functional declines with advancing age. Hippocampal function is influenced by ghrelin through hippocampus-expressed growth hormone secretagogue receptor (GHSR). Liver-expressed antimicrobial peptide 2 (LEAP2) is an endogenous GHSR antagonist that attenuates ghrelin signaling. Here, we measured plasma ghrelin and LEAP2 levels in a cohort of cognitively normal individuals older than 60 and found that LEAP2 increased with age while ghrelin (also referred to in literature as "acyl-ghrelin") marginally declined. In this cohort, plasma LEAP2/ghrelin molar ratios were inversely associated with Mini-Mental State Examination scores. Studies in mice showed an age-dependent inverse relationship between plasma LEAP2/ghrelin molar ratio and hippocampal lesions. In aged mice, restoration of the LEAP2/ghrelin balance to youth-associated levels with lentiviral shRNA Leap2 downregulation improved cognitive performance and mitigated various age-related hippocampal deficiencies such as CA1 region synaptic loss, declines in neurogenesis, and neuroinflammation. Our data collectively suggest that LEAP2/ghrelin molar ratio elevation may adversely affect hippocampal function and, consequently, cognitive performance; thus, it may serve as a biomarker of age-related cognitive decline. Moreover, targeting LEAP2 and ghrelin in a manner that lowers the plasma LEAP2/ghrelin molar ratio could benefit cognitive performance in elderly individuals for rejuvenation of memory.
Collapse
Affiliation(s)
- Jing Tian
- Department of Pharmacology and Toxicology and
| | - Lan Guo
- Higuchi Biosciences Center, University of Kansas, Lawrence, Kansas, USA
| | - Tienju Wang
- Department of Pharmacology and Toxicology and
| | - Kun Jia
- Department of Pharmacology and Toxicology and
| | - Russell H Swerdlow
- Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jeffrey M Zigman
- Departments of Internal Medicine and Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Heng Du
- Department of Pharmacology and Toxicology and
- Higuchi Biosciences Center, University of Kansas, Lawrence, Kansas, USA
- Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, Kansas, USA
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Hirono M, Nakata M. Ghrelin signaling in the cerebellar cortex enhances GABAergic transmission onto Purkinje cells. Sci Rep 2023; 13:2150. [PMID: 36750743 PMCID: PMC9905081 DOI: 10.1038/s41598-023-29226-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 01/31/2023] [Indexed: 02/09/2023] Open
Abstract
Ghrelin, an orexigenic peptide ligand for growth hormone secretagogue receptor 1a (GHS-R1a), occurs not only in the stomach but also in the brain, and modulates neuronal activity and synaptic efficacy. Previous studies showed that GHS-R1a exists in the cerebellum, and ghrelin facilitates spontaneous firing of Purkinje cells (PCs). However, the effects of ghrelin on cerebellar GABAergic transmission have yet to be elucidated. We found that ghrelin enhanced GABAergic transmission between molecular layer interneurons (MLIs) and PCs using electrophysiological recordings in mouse cerebellar slices. This finding was consistent with the possibility that blocking synaptic transmission enhanced the ghrelin-induced facilitation of PC firing. Ghrelin profoundly increased the frequency of spontaneous inhibitory postsynaptic currents (IPSCs) in PCs without affecting miniature or stimulation-evoked IPSCs, whereas it significantly facilitated spontaneous firing of MLIs. This facilitation of MLI spiking disappeared during treatments with blockers of GHS-R1a, type 1 transient receptor potential canonical (TRPC1) channels and KCNQ channels. These results suggest that both activating TRPC1 channels and inhibiting KCNQ channels occur downstream the ghrelin-GHS-R1a signaling pathway probably in somatodendritic sites of MLIs. Thus, ghrelin can control PC firing directly and indirectly via its modulation of GABAergic transmission, thereby impacting activity in cerebellar circuitry.
Collapse
Affiliation(s)
- Moritoshi Hirono
- Department of Physiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, Wakayama, 641-8509, Japan.
| | - Masanori Nakata
- Department of Physiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, Wakayama, 641-8509, Japan
| |
Collapse
|
6
|
Quantifying postsynaptic receptor dynamics: insights into synaptic function. Nat Rev Neurosci 2023; 24:4-22. [PMID: 36352031 DOI: 10.1038/s41583-022-00647-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 11/11/2022]
Abstract
The molecular composition of presynaptic and postsynaptic neuronal terminals is dynamic, and yet long-term stabilizations in postsynaptic responses are necessary for synaptic development and long-term plasticity. The need to reconcile these concepts is further complicated by learning- and memory-related plastic changes in the molecular make-up of synapses. Advances in single-particle tracking mean that we can now quantify the number and diffusive properties of specific synaptic molecules, while statistical thermodynamics provides a framework to analyse these molecular fluctuations. In this Review, we discuss the use of these approaches to gain quantitative descriptions of the processes underlying the turnover, long-term stability and plasticity of postsynaptic receptors and show how these can help us to understand the balance between local molecular turnover and synaptic structural identity and integrity.
Collapse
|
7
|
Ringuet MT, Furness JB, Furness SGB. G protein-coupled receptor interactions and modification of signalling involving the ghrelin receptor, GHSR1a. J Neuroendocrinol 2022; 34:e13077. [PMID: 34931385 DOI: 10.1111/jne.13077] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/05/2021] [Indexed: 12/28/2022]
Abstract
The growth hormone secretagogue receptor 1a (GHSR1a) is intriguing because of its potential as a therapeutic target and its diverse molecular interactions. Initial studies of the receptor focused on the potential therapeutic ability for growth hormone (GH) release to reduce wasting in aging individuals, as well as food intake regulation for treatment of cachexia. Known roles of GHSR1a now extend to regulation of neurogenesis, learning and memory, gastrointestinal motility, glucose/lipid metabolism, the cardiovascular system, neuronal protection, motivational salience, and hedonic feeding. Ghrelin, the endogenous agonist of GHSR1a, is primarily located in the stomach and is absent from the central nervous system (CNS), including the spinal cord. However, ghrelin in the circulation does have access to a small number of CNS sites, including the arcuate nucleus, which is important in feeding control. At some sites, such as at somatotrophs, GHSR1a has high constitutive activity. Typically, ghrelin-dependent and constitutive GHSR1a activation occurs via Gαq/11 pathways. In vitro and in vivo data suggest that GHSR1a heterodimerises with multiple G protein-coupled receptors (GPCRs), including dopamine D1 and D2, serotonin 2C, orexin, oxytocin and melanocortin 3 receptors (MCR3), as well as the MCR3 accessory protein, MRAP2, providing possible mechanisms for its many physiological effects. In all cases, the receptor interaction changes downstream signalling and the responses to receptor agonists. This review discusses the signalling mechanisms of GHSR1a alone and in combination with other GPCRs, and explores the physiological consequences of GHSR1a coupling with other GPCRs.
Collapse
Affiliation(s)
- Mitchell Ty Ringuet
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
| | - John Barton Furness
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | | |
Collapse
|
8
|
Ghosh-Swaby OR, Reichelt AC, Sheppard PAS, Davies J, Bussey TJ, Saksida LM. Metabolic hormones mediate cognition. Front Neuroendocrinol 2022; 66:101009. [PMID: 35679900 DOI: 10.1016/j.yfrne.2022.101009] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 05/18/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
Recent biochemical and behavioural evidence indicates that metabolic hormones not only regulate energy intake and nutrient content, but also modulate plasticity and cognition in the central nervous system. Disruptions in metabolic hormone signalling may provide a link between metabolic syndromes like obesity and diabetes, and cognitive impairment. For example, altered metabolic homeostasis in obesity is a strong determinant of the severity of age-related cognitive decline and neurodegenerative disease. Here we review the evidence that eating behaviours and metabolic hormones-particularly ghrelin, leptin, and insulin-are key players in the delicate regulation of neural plasticity and cognition. Caloric restriction and antidiabetic therapies, both of which affect metabolic hormone levels can restore metabolic homeostasis and enhance cognitive function. Thus, metabolic hormone pathways provide a promising target for the treatment of cognitive decline.
Collapse
Affiliation(s)
- Olivia R Ghosh-Swaby
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada
| | - Amy C Reichelt
- Faculty of Health and Medical Sciences, Adelaide Medical School, Adelaide, Australia
| | - Paul A S Sheppard
- Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Jeffrey Davies
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Timothy J Bussey
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada; Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Lisa M Saksida
- Schulich School of Medicine and Dentistry, Neuroscience Program, Western University, London, ON, Canada; Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, Western University, London, ON, Canada.
| |
Collapse
|
9
|
Mitre M, Saadipour K, Williams K, Khatri L, Froemke RC, Chao MV. Transactivation of TrkB Receptors by Oxytocin and Its G Protein-Coupled Receptor. Front Mol Neurosci 2022; 15:891537. [PMID: 35721318 PMCID: PMC9201241 DOI: 10.3389/fnmol.2022.891537] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/11/2022] [Indexed: 12/28/2022] Open
Abstract
Brain-derived Neurotrophic Factor (BDNF) binds to the TrkB tyrosine kinase receptor, which dictates the sensitivity of neurons to BDNF. A unique feature of TrkB is the ability to be activated by small molecules in a process called transactivation. Here we report that the brain neuropeptide oxytocin increases BDNF TrkB activity in primary cortical neurons and in the mammalian neocortex during postnatal development. Oxytocin produces its effects through a G protein-coupled receptor (GPCR), however, the receptor signaling events that account for its actions have not been fully defined. We find oxytocin rapidly transactivates TrkB receptors in bath application of acute brain slices of 2-week-old mice and in primary cortical culture by increasing TrkB receptor tyrosine phosphorylation. The effects of oxytocin signaling could be distinguished from the related vasopressin receptor. The transactivation of TrkB receptors by oxytocin enhances the clustering of gephyrin, a scaffold protein responsible to coordinate inhibitory responses. Because oxytocin displays pro-social functions in maternal care, cognition, and social attachment, it is currently a focus of therapeutic strategies in autism spectrum disorders. Interestingly, oxytocin and BDNF are both implicated in the pathophysiology of depression, schizophrenia, anxiety, and cognition. These results imply that oxytocin may rely upon crosstalk with BDNF signaling to facilitate its actions through receptor transactivation.
Collapse
Affiliation(s)
- Mariela Mitre
- Departments of Cell Biology, Neuroscience & Physiology, and Psychiatry, Skirball Institute for Biomolecular Medicine, New York, NY, United States
- Neuroscience Institute, New York University Langone Medical Center, New York, NY, United States
- Departments of Cell Biology, Psychiatry, New York University Langone Medical Center, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Langone Medical Center, New York, NY, United States
- Department of Otolaryngology, New York University Langone Medical Center, New York, NY, United States
- Center for Neural Science, New York University, New York, NY, United States
| | - Khalil Saadipour
- Departments of Cell Biology, Neuroscience & Physiology, and Psychiatry, Skirball Institute for Biomolecular Medicine, New York, NY, United States
| | - Kevin Williams
- Departments of Biology and Psychology, University of Georgia, Athens, GA, United States
| | - Latika Khatri
- Departments of Cell Biology, Neuroscience & Physiology, and Psychiatry, Skirball Institute for Biomolecular Medicine, New York, NY, United States
| | - Robert C. Froemke
- Departments of Cell Biology, Neuroscience & Physiology, and Psychiatry, Skirball Institute for Biomolecular Medicine, New York, NY, United States
- Neuroscience Institute, New York University Langone Medical Center, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Langone Medical Center, New York, NY, United States
- Department of Otolaryngology, New York University Langone Medical Center, New York, NY, United States
- Center for Neural Science, New York University, New York, NY, United States
| | - Moses V. Chao
- Departments of Cell Biology, Neuroscience & Physiology, and Psychiatry, Skirball Institute for Biomolecular Medicine, New York, NY, United States
- Neuroscience Institute, New York University Langone Medical Center, New York, NY, United States
- Departments of Cell Biology, Psychiatry, New York University Langone Medical Center, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Langone Medical Center, New York, NY, United States
- Center for Neural Science, New York University, New York, NY, United States
- *Correspondence: Moses V. Chao
| |
Collapse
|
10
|
Cai C, Guo Z, Chang X, Li Z, Wu F, He J, Cao T, Wang K, Shi N, Zhou H, Toan S, Muid D, Tan Y. Empagliflozin attenuates cardiac microvascular ischemia/reperfusion through activating the AMPKα1/ULK1/FUNDC1/mitophagy pathway. Redox Biol 2022; 52:102288. [PMID: 35325804 PMCID: PMC8938627 DOI: 10.1016/j.redox.2022.102288] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/07/2022] [Accepted: 03/12/2022] [Indexed: 02/07/2023] Open
Abstract
Mitophagy preserves microvascular structure and function during myocardial ischemia/reperfusion (I/R) injury. Empagliflozin, an anti-diabetes drug, may also protect mitochondria. We explored whether empagliflozin could reduce cardiac microvascular I/R injury by enhancing mitophagy. In mice, I/R injury induced luminal stenosis, microvessel wall damage, erythrocyte accumulation and perfusion defects in the myocardial microcirculation. Additionally, I/R triggered endothelial hyperpermeability and myocardial neutrophil infiltration, which upregulated adhesive factors and endothelin-1 but downregulated vascular endothelial cadherin and endothelial nitric oxide synthase in heart tissue. In vitro, I/R impaired the endothelial barrier function and integrity of cardiac microvascular endothelial cells (CMECs), while empagliflozin preserved CMEC homeostasis and thus maintained cardiac microvascular structure and function. I/R activated mitochondrial fission, oxidative stress and apoptotic signaling in CMECs, whereas empagliflozin normalized mitochondrial fission and fusion, neutralized supraphysiologic reactive oxygen species concentrations and suppressed mitochondrial apoptosis. Empagliflozin exerted these protective effects by activating FUNDC1-dependent mitophagy through the AMPKα1/ULK1 pathway. Both in vitro and in vivo, genetic ablation of AMPKα1 or FUNDC1 abolished the beneficial effects of empagliflozin on the myocardial microvasculature and CMECs. Taken together, the preservation of mitochondrial function through an activation of the AMPKα1/ULK1/FUNDC1/mitophagy pathway is the working mechanism of empagliflozin in attenuating cardiac microvascular I/R injury. Empagliflozin reduces I/R-induced microvascular damage. Empagliflozin suppresses I/R-induced endothelial cell damage. Empagliflozin activates FUNDC1-dependent mitophagy through the AMPKα1/ULK1 pathway. Ablation of FUNDC1 or AMPKα1 abolishes the protective effects of empagliflozin against I/R-induced microvascular damage.
Collapse
|
11
|
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]
|
12
|
Sustkova-Fiserova M, Charalambous C, Khryakova A, Certilina A, Lapka M, Šlamberová R. The Role of Ghrelin/GHS-R1A Signaling in Nonalcohol Drug Addictions. Int J Mol Sci 2022; 23:761. [PMID: 35054944 PMCID: PMC8776007 DOI: 10.3390/ijms23020761] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 01/27/2023] Open
Abstract
Drug addiction causes constant serious health, social, and economic burden within the human society. The current drug dependence pharmacotherapies, particularly relapse prevention, remain limited, unsatisfactory, unreliable for opioids and tobacco, and even symptomatic for stimulants and cannabinoids, thus, new more effective treatment strategies are researched. The antagonism of the growth hormone secretagogue receptor type A (GHS-R1A) has been recently proposed as a novel alcohol addiction treatment strategy, and it has been intensively studied in experimental models of other addictive drugs, such as nicotine, stimulants, opioids and cannabinoids. The role of ghrelin signaling in these drugs effects has also been investigated. The present review aims to provide a comprehensive overview of preclinical and clinical studies focused on ghrelin's/GHS-R1A possible involvement in these nonalcohol addictive drugs reinforcing effects and addiction. Although the investigation is still in its early stage, majority of the existing reviewed experimental results from rodents with the addition of few human studies, that searched correlations between the genetic variations of the ghrelin signaling or the ghrelin blood content with the addictive drugs effects, have indicated the importance of the ghrelin's/GHS-R1As involvement in the nonalcohol abused drugs pro-addictive effects. Further research is necessary to elucidate the exact involved mechanisms and to verify the future potential utilization and safety of the GHS-R1A antagonism use for these drug addiction therapies, particularly for reducing the risk of relapse.
Collapse
Affiliation(s)
- Magdalena Sustkova-Fiserova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Chrysostomos Charalambous
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Anna Khryakova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Alina Certilina
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Marek Lapka
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Romana Šlamberová
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic;
| |
Collapse
|
13
|
Labarthe A, Zizzari P, Fiquet O, Lebrun N, Veldhuis JD, Roelfsema F, Chauveau C, Bohlooly-Y M, Epelbaum J, Tolle V. Effect of Growth Hormone Secretagogue Receptor Deletion on Growth, Pulsatile Growth Hormone Secretion, and Meal Pattern in Male and Female Mice. Neuroendocrinology 2022; 112:215-234. [PMID: 33774644 DOI: 10.1159/000516147] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 03/25/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION While the vast majority of research investigating the role of ghrelin or its receptor, GHS-R1a, in growth, feeding, and metabolism has been conducted in male rodents, very little is known about sex differences in this system. Furthermore, the role of GHS-R1a signaling in the control of pulsatile GH secretion and its link with growth or metabolic parameters has never been characterized. METHODS We assessed the sex-specific contribution of GHS-R1a signaling in the activity of the GH/IGF-1 axis, metabolic parameters, and feeding behavior in adolescent (5-6 weeks old) or adult (10-19 weeks old) GHS-R KO (Ghsr-/-) and WT (Ghsr+/+) male and female mice. RESULTS Adult Ghsr-/- male and female mice displayed deficits in weight and linear growth that were correlated with reduced GH pituitary contents in males only. GHS-R1a deletion was associated with reduced meal frequency and increased meal intervals, as well as reduced hypothalamic GHRH and NPY mRNA in males, not females. In adult, GH release from Ghsr-/- mice pituitary explants ex vivo was reduced independently of the sex. However, in vivo pulsatile GH secretion decreased in adult but not adolescent Ghsr-/- females, while in males, GHS-R1a deletion was associated with reduction in pulsatile GH secretion during adolescence exclusively. In males, linear growth did not correlate with pulsatile GH secretion, but rather with ApEn, a measure that reflects irregularity of the rhythmic secretion. Fat mass, plasma leptin concentrations, or ambulatory activity did not predict differences in GH secretion. DISCUSSION/CONCLUSION These results point to a sex-dependent dimorphic effect of GHS-R1a signaling to modulate pulsatile GH secretion and meal pattern in mice with different compensatory mechanisms occurring in the hypothalamus of adult males and females after GHS-R1a deletion. Altogether, we show that GHS-R1a signaling plays a more critical role in the regulation of pulsatile GH secretion during adolescence in males and adulthood in females.
Collapse
Affiliation(s)
- Alexandra Labarthe
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Philippe Zizzari
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Oriane Fiquet
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Nicolas Lebrun
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Johannes D Veldhuis
- Endocrine Research Unit, Department of Medicine, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, New York, USA
| | - Ferdinand Roelfsema
- Department of Internal Medicine, Section of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, The Netherlands
| | - Christophe Chauveau
- Marrow Adiposity and Bone Lab - MABLab ULR 4490, University Littoral Côte d'Opale, Boulogne-sur-Mer, France
- University Lille, CHU Lille, Lille, France
| | - Mohammad Bohlooly-Y
- Translational Genomics, Discovery Sciences, Biopharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Jacques Epelbaum
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
- UMR CNRS/MNHN 7179, Mécanismes Adaptatifs et Evolution, Brunoy, France
| | - Virginie Tolle
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| |
Collapse
|
14
|
Aberrant hippocampal transmission and behavior in mice with a stargazin mutation linked to intellectual disability. Mol Psychiatry 2022; 27:2457-2469. [PMID: 35256745 PMCID: PMC9135633 DOI: 10.1038/s41380-022-01487-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/31/2022] [Accepted: 02/14/2022] [Indexed: 11/08/2022]
Abstract
Mutations linked to neurodevelopmental disorders, such as intellectual disability (ID), are frequently found in genes that encode for proteins of the excitatory synapse. Transmembrane AMPA receptor regulatory proteins (TARPs) are AMPA receptor auxiliary proteins that regulate crucial aspects of receptor function. Here, we investigate a mutant form of the TARP family member stargazin, described in an ID patient. Molecular dynamics analyses predicted that the ID-associated stargazin variant, V143L, weakens the overall interface of the AMPAR:stargazin complex and impairs the stability of the complex. Knock-in mice harboring the V143L stargazin mutation manifest cognitive and social deficits and hippocampal synaptic transmission defects, resembling phenotypes displayed by ID patients. In the hippocampus of stargazin V143L mice, CA1 neurons show impaired spine maturation, abnormal synaptic transmission and long-term potentiation specifically in basal dendrites, and synaptic ultrastructural alterations. These data suggest a causal role for mutated stargazin in the pathogenesis of ID and unveil a new role for stargazin in the development and function of hippocampal synapses.
Collapse
|
15
|
Shevchouk OT, Tufvesson-Alm M, Jerlhag E. An Overview of Appetite-Regulatory Peptides in Addiction Processes; From Bench to Bed Side. Front Neurosci 2021; 15:774050. [PMID: 34955726 PMCID: PMC8695496 DOI: 10.3389/fnins.2021.774050] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
There is a substantial need for new pharmacological treatments of addiction, and appetite-regulatory peptides are implied as possible candidates. Appetite regulation is complex and involves anorexigenic hormones such as glucagon-like peptide-1 (GLP-1) and amylin, and orexigenic peptides like ghrelin and all are well-known for their effects on feeding behaviors. This overview will summarize more recent physiological aspects of these peptides, demonstrating that they modulate various aspects of addiction processes. Findings from preclinical, genetic, and experimental clinical studies exploring the association between appetite-regulatory peptides and the acute or chronic effects of addictive drugs will be introduced. Short or long-acting GLP-1 receptor agonists independently attenuate the acute rewarding properties of addictive drugs or reduce the chronic aspects of drugs. Genetic variation of the GLP-1 system is associated with alcohol use disorder. Also, the amylin pathway modulates the acute and chronic behavioral responses to addictive drugs. Ghrelin has been shown to activate reward-related behaviors. Moreover, ghrelin enhances, whereas pharmacological or genetic suppression of the ghrelin receptor attenuates the responses to various addictive drugs. Genetic studies and experimental clinical studies further support the associations between ghrelin and addiction processes. Further studies should explore the mechanisms modulating the ability of appetite-regulatory peptides to reduce addiction, and the effects of combination therapies or different diets on substance use are warranted. In summary, these studies provide evidence that appetite-regulatory peptides modulate reward and addiction processes, and deserve to be investigated as potential treatment target for addiction.
Collapse
Affiliation(s)
- Olesya T Shevchouk
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Maximilian Tufvesson-Alm
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
16
|
Airapetov MI, Eresko SO, Lebedev AA, Bychkov ER, Shabanov PD. Expression of the growth hormone secretagogue receptor 1a (GHS-R1a) in the brain. Physiol Rep 2021; 9:e15113. [PMID: 34755494 PMCID: PMC8578894 DOI: 10.14814/phy2.15113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/23/2021] [Accepted: 10/26/2021] [Indexed: 12/17/2022] Open
Abstract
The review presents data on the expression of growth hormone secretagogue receptor 1a (GHS-R1a) in the brain regions in model animals (zebrafish, rodents, primates), and in the human brain. Studies show widespread distribution of the receptor in the brain, which evidences the involvement of the receptor in many physiological processes. Using various organisms, data have been obtained regarding the participation of the GHS-R1a in the regulation of the anti- and pro-inflammatory response, proliferation, and apoptosis. It is known that the receptor plays an important role in eating behavior and is also involved in the pathogenetic mechanisms of drug addiction, obesity, and chronic alcohol consumption. Based on this, research is underway with the use of various therapeutic agents that can be used for the pharmacological correction of these conditions. This review also presents hypothetical pathways of intracellular signaling, in which GHS-R1a may participate. A complete understanding of these mechanisms has not yet been reached. The ghrelin intracellular signaling seem to be specific to brain region and, probably, also depend on the metabolic or stress status of the organism.
Collapse
Affiliation(s)
- Marat I. Airapetov
- Department of NeuropharmacologyInstitute of Experimental MedicineSt. PetersburgRussia
- Department of PharmacologySt. Petersburg State Pediatric Medical UniversitySt. PetersburgRussia
| | - Sergei O. Eresko
- Department of NeuropharmacologyInstitute of Experimental MedicineSt. PetersburgRussia
- Research and Training Center of Molecular and Cellular TechnologiesSt. Petersburg State Chemical Pharmaceutical UniversitySt PetersburgRussia
- Department of BiologySaint‐Petersburg State UniversitySt PetersburgRussia
| | - Andrei A. Lebedev
- Department of NeuropharmacologyInstitute of Experimental MedicineSt. PetersburgRussia
| | - Evgenii R. Bychkov
- Department of NeuropharmacologyInstitute of Experimental MedicineSt. PetersburgRussia
- Department of PharmacologyKirov Military Medical AcademySt. PetersburgRussia
| | - Petr D. Shabanov
- Department of NeuropharmacologyInstitute of Experimental MedicineSt. PetersburgRussia
- Department of PharmacologyKirov Military Medical AcademySt. PetersburgRussia
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Airapetov MI, Eresko SO, Lebedev AA, Bychkov ER, Shabanov PD. Expression of Ghrelin Receptor GHS-R1a in the Brain (Mini Review). Mol Biol 2021. [DOI: 10.1134/s002689332103002x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|