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Tufvesson-Alm M, Zhang Q, Aranäs C, Blid Sköldheden S, Edvardsson CE, Jerlhag E. Decoding the influence of central LEAP2 on food intake and its effect on accumbal dopamine release. Prog Neurobiol 2024; 236:102615. [PMID: 38641041 DOI: 10.1016/j.pneurobio.2024.102615] [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: 11/09/2023] [Revised: 04/03/2024] [Accepted: 04/16/2024] [Indexed: 04/21/2024]
Abstract
The gut-brain peptide ghrelin and its receptor are established as a regulator of hunger and reward-processing. However, the recently recognized ghrelin receptor inverse agonist, liver-expressed antimicrobial peptide 2 (LEAP2), is less characterized. The present study aimed to elucidate LEAP2s central effect on reward-related behaviors through feeding and its mechanism. LEAP2 was administrated centrally in mice and effectively reduced feeding and intake of palatable foods. Strikingly, LEAP2s effect on feeding was correlated to the preference of the palatable food. Further, LEAP2 reduced the rewarding memory of high preference foods, and attenuated the accumbal dopamine release associated with palatable food exposure and eating. Interestingly, LEAP2 was widely expressed in the brain, and particularly in reward-related brain areas such as the laterodorsal tegmental area (LDTg). This expression was markedly altered when allowed free access to palatable foods. Accordingly, infusion of LEAP2 into LDTg was sufficient to transiently reduce acute palatable food intake. Taken together, the present results show that central LEAP2 has a profound effect on dopaminergic reward signaling associated with food and affects several aspects of feeding. The present study highlights LEAP2s effect on reward, which may have applications for obesity and other reward-related psychiatric and neurological disorders.
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Affiliation(s)
- Maximilian Tufvesson-Alm
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, Gothenburg SE-405 30, Sweden
| | - Qian Zhang
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, Gothenburg SE-405 30, Sweden
| | - Cajsa Aranäs
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, Gothenburg SE-405 30, Sweden
| | - Sebastian Blid Sköldheden
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, Gothenburg SE-405 30, Sweden
| | - Christian E Edvardsson
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, Gothenburg SE-405 30, Sweden
| | - Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 13A, Gothenburg SE-405 30, Sweden.
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2
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Lang Y, Liu Y, Ye C, Tang X, Cheng Z, Xie L, Feng L, Liu Y. Loss of LEAP-2 alleviates obesity-induced myocardial injury by regulating macrophage polarization. Exp Cell Res 2023; 430:113702. [PMID: 37414204 DOI: 10.1016/j.yexcr.2023.113702] [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: 12/06/2022] [Revised: 06/24/2023] [Accepted: 06/27/2023] [Indexed: 07/08/2023]
Abstract
BACKGROUND Obesity is a serious public health issue worldwide, which is a risk factor of cardiovascular disorders. Obesity has been shown to be associated with subclinical myocardial injury, increasing the risk of heart failure. Our study aims to explore novel mechanisms underlying obesity-induced myocardial injury. METHODS Mice were fed a high-fat diet (HFD) to establish a mouse model of obesity, and serum levels of TG, TCH, LDL, CK-MB, LDH, cTnI and BNP were examined. Inflammatory response was evaluated by determining the expression and secretion of proinflammatory cytokines IL-1β and TNF-α. Macrophage infiltration in the heart was examined by IHC staining, and H&E staining was applied to evaluate myocardial injury. Primary peritoneal macrophages were isolated from mice and treated with palmitic acid (PA). Macrophage polarization was evaluated by determine the expression of CCL2, iNOS, CD206 and arginase I via Western blot, RT-qPCR, and flow cytometry. Co-IP assays were performed to examine the interaction between LEAP-2, GHSR and ghrelin. RESULTS Hyperlipidemia, increased proinflammatory cytokines and myocardial injury were observed in mice with obesity, and silencing of LEAP-2 ameliorated HFD-induced hyperlipidemia, inflammation, and myocardial injury. Moreover, HFD-induced macrophage infiltration and M1 polarization were reversed by LEAP-2 knockdown in mice. Furthermore, silencing of LEAP-2 suppressed PA-induced M1 polarization but enhanced M2 polarization in vitro. LEAP-2 interacted with GHSR in macrophages, and knockdown of LEAP-2 promoted the interaction of GHSR and ghrelin. Overexpression of ghrelin enhanced LEAP-1 silencing-mediated suppression of inflammatory response and upregulation of M2 polarization in PA-induced macrophages. CONCLUSION Knockdown of LEAP-2 ameliorates obesity-induced myocardial injury via promoting M2 polarization.
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Affiliation(s)
- Yuanyuan Lang
- The Image Center, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Yanling Liu
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Chunfeng Ye
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Xiaomin Tang
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Zugen Cheng
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Lixin Xie
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Lihua Feng
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Yang Liu
- Pediatrics, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China.
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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: 0] [Impact Index Per Article: 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.
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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
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Ghrelin system in Alzheimer's disease. Curr Opin Neurobiol 2023; 78:102655. [PMID: 36527939 PMCID: PMC10395051 DOI: 10.1016/j.conb.2022.102655] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/16/2022] [Indexed: 12/23/2022]
Abstract
Alzheimer's disease (AD) is the most common type of dementia in seniors. Current efforts to understand the etiopathogenesis of this neurodegenerative disorder have brought forth questions about systemic factors in the development of AD. Ghrelin is a brain-gut peptide that is activated by ghrelin O-acyltransferase (GOAT) and signals via its receptor, growth hormone secretagogue receptor (GHSR). With increasing recognition of the neurotropic effects of ghrelin, the role of ghrelin system deregulation in the development of AD has been accentuated in recent years. In this review, we summarized recent research progress regarding the mechanisms of ghrelin signaling dysregulation and its contribution to AD brain pathology. In addition, we also discussed the therapeutic potential of strategies targeting ghrelin signaling for the treatment of this neurological disease.
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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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Jerlhag E. Animal studies reveal that the ghrelin pathway regulates alcohol-mediated responses. Front Psychiatry 2023; 14:1050973. [PMID: 36970276 PMCID: PMC10030715 DOI: 10.3389/fpsyt.2023.1050973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 02/21/2023] [Indexed: 03/29/2023] Open
Abstract
Alcohol use disorder (AUD) is often described as repeated phases of binge drinking, compulsive alcohol-taking, craving for alcohol during withdrawal, and drinking with an aim to a reduce the negative consequences. Although multifaceted, alcohol-induced reward is one aspect influencing the former three of these. The neurobiological mechanisms regulating AUD processes are complex and one of these systems is the gut-brain peptide ghrelin. The vast physiological properties of ghrelin are mediated via growth hormone secretagogue receptor (GHSR, ghrelin receptor). Ghrelin is well known for its ability to control feeding, hunger, and metabolism. Moreover, ghrelin signaling appears central for alcohol-mediated responses; findings reviewed herein. In male rodents GHSR antagonism reduces alcohol consumption, prevents relapse drinking, and attenuates the motivation to consume alcohol. On the other hand, ghrelin increases the consumption of alcohol. This ghrelin-alcohol interaction is also verified to some extent in humans with high alcohol consumption. In addition, either pharmacological or genetic suppression of GHSR decreases several alcohol-related effects (behavioral or neurochemical). Indeed, this suppression blocks the alcohol-induced hyperlocomotion and dopamine release in nucleus accumbens as well as ablates the alcohol reward in the conditioned place preference model. Although not fully elucidated, this interaction appears to involve areas central for reward, such as the ventral tegmental area (VTA) and brain nodes targeted by VTA projections. As reviewed briefly, the ghrelin pathway does not only modulate alcohol-mediated effects, it regulates reward-related behaviors induced by addictive drugs. Although personality traits like impulsivity and risk-taking behaviors are common in patients with AUD, the role of the ghrelin pathway thereof is unknown and remains to be studied. In summary, the ghrelin pathway regulates addiction processes like AUD and therefore the possibility that GHSR antagonism reduces alcohol or drug-taking should be explored in randomized clinical trials.
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Chen RB, Wang QY, Wang YY, Wang YD, Liu JH, Liao ZZ, Xiao XH. Feeding-induced hepatokines and crosstalk with multi-organ: A novel therapeutic target for Type 2 diabetes. Front Endocrinol (Lausanne) 2023; 14:1094458. [PMID: 36936164 PMCID: PMC10020511 DOI: 10.3389/fendo.2023.1094458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 02/15/2023] [Indexed: 03/06/2023] Open
Abstract
Hyperglycemia, which can be caused by either an insulin deficit and/or insulin resistance, is the main symptom of Type 2 diabetes, a significant endocrine metabolic illness. Conventional medications, including insulin and oral antidiabetic medicines, can alleviate the signs of diabetes but cannot restore insulin release in a physiologically normal amount. The liver detects and reacts to shifts in the nutritional condition that occur under a wide variety of metabolic situations, making it an essential organ for maintaining energy homeostasis. It also performs a crucial function in glucolipid metabolism through the secretion of hepatokines. Emerging research shows that feeding induces hepatokines release, which regulates glucose and lipid metabolism. Notably, these feeding-induced hepatokines act on multiple organs to regulate glucolipotoxicity and thus influence the development of T2DM. In this review, we focus on describing how feeding-induced cross-talk between hepatokines, including Adropin, Manf, Leap2 and Pcsk9, and metabolic organs (e.g.brain, heart, pancreas, and adipose tissue) affects metabolic disorders, thus revealing a novel approach for both controlling and managing of Type 2 diabetes as a promising medication.
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Affiliation(s)
- Rong-Bin Chen
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Qi-Yu Wang
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
- Department of Clinical Laboratory Medicine, Institution of Microbiology and Infectious Diseases, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Yuan-Yuan Wang
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Ya-Di Wang
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Jiang-Hua Liu
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Zhe-Zhen Liao
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
- *Correspondence: Xin-Hua Xiao, ; Zhe-Zhen Liao,
| | - Xin-Hua Xiao
- Department of Metabolism and Endocrinology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
- *Correspondence: Xin-Hua Xiao, ; Zhe-Zhen Liao,
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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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Tufvesson-Alm M, Shevchouk OT, Jerlhag E. Insight into the role of the gut-brain axis in alcohol-related responses: Emphasis on GLP-1, amylin, and ghrelin. Front Psychiatry 2022; 13:1092828. [PMID: 36699502 PMCID: PMC9868418 DOI: 10.3389/fpsyt.2022.1092828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Alcohol use disorder (AUD) contributes substantially to global morbidity and mortality. Given the heterogenicity of this brain disease, available pharmacological treatments only display efficacy in sub-set of individuals. The need for additional treatment options is thus substantial and is the goal of preclinical studies unraveling neurobiological mechanisms underlying AUD. Although these neurobiological processes are complex and numerous, one system gaining recent attention is the gut-brain axis. Peptides of the gut-brain axis include anorexigenic peptide like glucagon-like peptide-1 (GLP-1) and amylin as well as the orexigenic peptide ghrelin. In animal models, agonists of the GLP-1 or amylin receptor and ghrelin receptor (GHSR) antagonists reduce alcohol drinking, relapse drinking, and alcohol-seeking. Moreover, these three gut-brain peptides modulate alcohol-related responses (behavioral and neurochemical) in rodents, suggesting that the alcohol reduction may involve a suppression of alcohol's rewarding properties. Brain areas participating in the ability of these gut-brain peptides to reduce alcohol-mediated behaviors/neurochemistry involve those important for reward. Human studies support these preclinical studies as polymorphisms of the genes encoding for GLP-1 receptor or the ghrelin pathway are associated with AUD. Moreover, a GLP-1 receptor agonist decreases alcohol drinking in overweight patients with AUD and an inverse GHSR agonist reduces alcohol craving. Although preclinical and clinical studies reveal an interaction between the gut-brain axis and AUD, additional studies should explore this in more detail.
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Affiliation(s)
- Maximilian Tufvesson-Alm
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Olesya T Shevchouk
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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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.
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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
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11
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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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