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Guan K, Ye M, Guo A, Chen X, Shan Y, Li X. Deficiency of leap2 promotes somatic growth in zebrafish: Involvement of the growth hormone system. Heliyon 2024; 10:e36397. [PMID: 39347412 PMCID: PMC11437977 DOI: 10.1016/j.heliyon.2024.e36397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 08/13/2024] [Accepted: 08/14/2024] [Indexed: 10/01/2024] Open
Abstract
Purpose Liver-expressed antimicrobial peptide-2 (LEAP2) is identified as an endogenous antagonist and inverse agonist of the growth hormone secretagogue receptor type 1a (GHSR1a), its effect on the GHSR1a is contrary to the role of GHRELIN. Growth hormone (GH) is a crucial hormone for early development. Previous studies report that LEAP2 dose-dependently attenuates ghrelin-induced GH secretion, and Leap2-knockout mice exhibit increased plasma GH levels after GHRELIN administration. Clinical data revealed a possible correlation between LEAP2 and height development. However, the role of LEAP2 in early development remains unclear. This study aimed to investigate the role of LEAP2 in early development using leap2 mutant zebrafish larvae as a model. Method We analyzed the conservation of LEAP2 peptide across multiple species and generated leap2 mutants in zebrafish by CRISPR-Cas9, dynamically observed and measured the growth and development of zebrafish larvae from fertilization to 5 day post fertilization (dpf). In situ hybridization, transcriptome sequencing, quantitative real-time PCR and Western blot were used to detect the expression levels of GH and its signaling in early stage of embryonic development. Result Our data demonstrate that zebrafish with a knockout of the leap2 gene display a significant increase in hatching rate, body length, and the distance between their eyes, all without visible developmental defects in the early stages of development. In addition, both RNA and protein analyses revealed a significant increase in GH expression in leap2 mutant. Conclusion In general, this study demonstrates that LEAP2 regulates the expression of GH during early development, particularly influencing body length.
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Affiliation(s)
- Kaiyu Guan
- Zhejiang Clinical Research Center for Mental Disorders, The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
- Peking University Sixth Hospital, Peking University Institute of Mental Health, Beijing, China
| | - Minjie Ye
- Zhejiang Clinical Research Center for Mental Disorders, The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Anqi Guo
- Zhejiang Clinical Research Center for Mental Disorders, The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Xiaoyu Chen
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Yunfeng Shan
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Xi Li
- Zhejiang Clinical Research Center for Mental Disorders, The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
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Shu X, Chen Z, Zheng X, Hua G, Zhuang W, Zhang J, Chen J. Quail GHRL and LEAP2 gene cloning, polymorphism detection, phylogenetic analysis, tissue expression profiling and its association analysis with feed intake. Gene 2024; 918:148479. [PMID: 38636815 DOI: 10.1016/j.gene.2024.148479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 03/29/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024]
Abstract
The GHRL, LEAP2, and GHSR system have recently been identified as important regulators of feed intake in mammals and chickens. However, the complete cloning of the quail GHRL (qGHRL) and quail LEAP2 (qLEAP2) genes, as well as their association with feed intake, remains unclear. This study cloned the entire qGHRL and qLEAP2 cDNA sequence in Chinese yellow quail (Coturnix japonica), including the 5' and 3' untranslated regions. Sanger sequencing analysis revealed no missense mutations in the coding region of qGHRL and qLEAP2. Subsequently, phylogenetic analysis and protein homology alignment were conducted on the qGHRL and qLEAP2 in major poultry species. The findings of this research indicated that the qGHRL and qLEAP2 sequences exhibit a high degree of similarity with those of chicken and turkey. Specifically, the N-terminal 6 amino acids of GHRL mature peptides and all the mature peptide sequence of LEAP2 exhibited consistent patterns across all species examined. The analysis of tissue gene expression profiles indicated that qGHRL was primarily expressed in the proventriculus and brain tissue, whereas qLEAP2 exhibited higher expression levels in the intestinal tissue, kidney, and liver tissue, differing slightly from previous studies conducted on chicken. It is necessary to investigate the significance of elevated expression of qGHRL in brain and qLEAP2 in kidney in the future. Further research has shown that the expression of qLEAP2 can quickly respond to changes in different energy states, whereas qGHRL does not exhibit the same capability. Overall, this study successfully cloned the complete cDNA sequences of qGHRL and qLEAP2, and conducted a comprehensive examination of their tissue expression profiles and gene expression levels in the main expressing organs across different energy states. Our current findings suggested that qLEAP2 is highly expressed in the liver, intestine, and kidney, and its expression level is regulated by feed intake.
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Affiliation(s)
- Xin Shu
- Jiangsu Key Laboratory of Sericultural Biology and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Ziwei Chen
- Jiangsu Key Laboratory of Sericultural Biology and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Xiaotong Zheng
- Jiangsu Key Laboratory of Sericultural Biology and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Guoying Hua
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Wuchao Zhuang
- Jiangsu Key Laboratory of Sericultural Biology and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Jilong Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Jianfei Chen
- Jiangsu Key Laboratory of Sericultural Biology and Animal Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Scientific Research Center, Chinese Academy of Agricultural Sciences, Zhenjiang, China.
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3
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Wu H, Hoare BL, Handley TNG, Akhter Hossain M, Bathgate RAD. Development of a synthetic relaxin-3/INSL5 chimeric peptide ligand for NanoBiT complementation binding assays. Biochem Pharmacol 2024; 224:116238. [PMID: 38677442 DOI: 10.1016/j.bcp.2024.116238] [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: 01/16/2024] [Revised: 04/09/2024] [Accepted: 04/25/2024] [Indexed: 04/29/2024]
Abstract
INSL5 and relaxin-3 are relaxin family peptides with important roles in gut and brain function, respectively. They mediate their actions through the class A GPCRs RXFP4 and RXFP3. RXFP4 has been proposed to be a therapeutic target for colon motility disorders whereas RXFP3 targeting could be effective for neurological conditions such as anxiety. Validation of these targets has been limited by the lack of specific ligands and the availability of robust ligand-binding assays for their development. In this study, we have utilized NanoBiT complementation to develop a SmBiT-conjugated tracer for use with LgBiT-fused RXFP3 and RXFP4. The low affinity between LgBiT:SmBiT should result in a low non-specific luminescence signal and enable the quantification of binding without the tedious separation of non-bound ligands. We used solid-phase peptide synthesis to produce a SmBiT-labelled RXFP3/4 agonist, R3/I5, where SmBiT was conjugated to the B-chain N-terminus via a PEG12 linker. Both SmBiT-R3/I5 and R3/I5 were synthesized and purified in high purity and yield. Stable HEK293T cell lines expressing LgBiT-RXFP3 and LgBiT-RXFP4 were produced and demonstrated normal signaling in response to the synthetic R3/I5 peptide. Binding was first characterized in whole-cell binding kinetic assays validating that the SmBiT-R3/I5 bound to both cell lines with nanomolar affinity with minimal non-specific binding without bound and free SmBiT-R3/I5 separation. We then optimized membrane binding assays, demonstrating easy and robust analysis of both saturation and competition binding from frozen membranes. These assays therefore provide an appropriate rigorous binding assay for the high-throughput analysis of RXFP3 and RXFP4 ligands.
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Affiliation(s)
- Hongkang Wu
- The Florey, University of Melbourne, Victoria, Australia
| | | | | | - Mohammed Akhter Hossain
- The Florey, University of Melbourne, Victoria, Australia; School of Chemistry, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
| | - Ross A D Bathgate
- The Florey, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
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Tuero C, Becerril S, Ezquerro S, Neira G, Frühbeck G, Rodríguez A. Molecular and cellular mechanisms underlying the hepatoprotective role of ghrelin against NAFLD progression. J Physiol Biochem 2023; 79:833-849. [PMID: 36417140 DOI: 10.1007/s13105-022-00933-1] [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: 09/06/2022] [Accepted: 11/12/2022] [Indexed: 11/24/2022]
Abstract
The underlying mechanisms for the development and progression of nonalcoholic fatty liver disease (NAFLD) are complex and multifactorial. Within the last years, experimental and clinical evidences support the role of ghrelin in the development of NAFLD. Ghrelin is a gut hormone that plays a major role in the short-term regulation of appetite and long-term regulation of adiposity. The liver constitutes a target for ghrelin, where this gut-derived peptide triggers intracellular pathways regulating lipid metabolism, inflammation, and fibrosis. Interestingly, circulating ghrelin levels are altered in patients with metabolic diseases, such as obesity, type 2 diabetes, and metabolic syndrome, which, in turn, are well-known risk factors for the pathogenesis of NAFLD. This review summarizes the molecular and cellular mechanisms involved in the hepatoprotective action of ghrelin, including the reduction of hepatocyte lipotoxicity via autophagy and fatty acid β-oxidation, mitochondrial dysfunction, endoplasmic reticulum stress and programmed cell death, the reversibility of the proinflammatory phenotype in Kupffer cells, and the inactivation of hepatic stellate cells. Together, the metabolic and inflammatory pathways regulated by ghrelin in the liver support its potential as a therapeutic target to prevent NAFLD in patients with metabolic disorders.
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Affiliation(s)
- Carlota Tuero
- Department of General Surgery, Clínica Universidad de Navarra, School of Medicine, University of Navarra, Pamplona, Spain
| | - Sara Becerril
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008, Pamplona, Irunlarrea 1, Spain
- CIBER Fisiopatología de La Obesidad Y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Silvia Ezquerro
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008, Pamplona, Irunlarrea 1, Spain
| | - Gabriela Neira
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008, Pamplona, Irunlarrea 1, Spain
| | - Gema Frühbeck
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008, Pamplona, Irunlarrea 1, Spain
- CIBER Fisiopatología de La Obesidad Y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
- Department of Endocrinology & Nutrition, Clínica Universidad de Navarra, Pamplona, Spain
| | - Amaia Rodríguez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008, Pamplona, Irunlarrea 1, Spain.
- CIBER Fisiopatología de La Obesidad Y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain.
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5
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Li HZ, Wang YF, Zheng YS, Liu YL, Xu ZG, Guo ZY. The ghrelin receptor GHSR has two efficient agonists in the lobe-finned fish Latimeria chalumnae. Biochem Biophys Res Commun 2023; 679:110-115. [PMID: 37677979 DOI: 10.1016/j.bbrc.2023.09.002] [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: 08/14/2023] [Revised: 08/25/2023] [Accepted: 09/01/2023] [Indexed: 09/09/2023]
Abstract
The peptide hormone ghrelin (an agonist) and LEAP2 (an antagonist) play important functions in energy metabolism via their receptor GHSR, an A-class G protein-coupled receptor. Ghrelin, LEAP2, and GHSR are widely present from fishes to mammals. However, our recent study suggested that fish GHSRs have different binding properties to ghrelin: a GHSR from the lobe-finned fish Latimeria chalumnae (coelacanth) is efficiently activated by ghrelin, but GHSRs from the ray-finned fish Danio rerio (zebrafish) and Larimichthys crocea (large yellow croaker) have lost binding to ghrelin. Do fish GHSRs use another peptide as their agonist? In the present study we tested to two fish motilins from D. rerio and L. chalumnae because motilin is distantly related to ghrelin. In ligand binding and activation assays, the fish GHSRs from D. rerio and L. crocea displayed no detectable or very low binding to all tested motilins; however, the fish GHSR from L. chalumnae bound to its motilin with high affinity and was efficiently activated by it. Therefore, it seemed that motilin is not a ligand for GHSR in the ray-finned fish D. rerio and L. crocea, but is an efficient agonist for GHSR in the lobe-finned fish L. chalumnae, one of the closest fish relatives of tetrapods. The results of present study suggested that GHSR might have two efficient agonists, ghrelin and motilin, in ancient fishes; however, this feature might be only preserved in some extant fishes with ancient evolutionary origins.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Fen Wang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yong-Shan Zheng
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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6
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Li HZ, Shao XX, Wang YF, Liu YL, Xu ZG, Guo ZY. LEAP2 is a more conserved ligand than ghrelin for fish GHSRs. Biochimie 2023; 209:10-19. [PMID: 36669723 DOI: 10.1016/j.biochi.2023.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/10/2022] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Recently, liver-expressed antimicrobial peptide 2 (LEAP2) was identified as an endogenous antagonist and an inverse agonist of the ghrelin receptor GHSR. However, its functions in lower vertebrates are not well understood. Our recent study demonstrated that both LEAP2 and ghrelin are functional towards a fish GHSR from Latimeria chalumnae, an extant coelacanth believed to be one of the closest ancestors of tetrapods. However, amino acid sequence alignment identified that the 6.58 position (Ballesteros-Weinstein numbering system) of most fish GHSRs are not occupied by an aromatic Phe residue, which is absolutely conserved in all known GHSRs from amphibians to mammals, and is responsible for human GHSR binding to its agonist, ghrelin. To test whether these unusual fish receptors are functional, we studied the ligand binding properties of three representative fish GHSRs, two from Danio rerio (zebrafish) and one from Larimichthys crocea (large yellow croaker). After overexpression in human embryonic kidney 293T cells, the three fish GHSRs retained normal binding to all tested LEAP2s, except for a second LEAP2 from L. crocea. However, they displayed almost no binding to all chemically synthesized n-octanoylated ghrelins, despite these ghrelins all retaining normal function towards human and coelacanth GHSRs. Thus, it seems that LEAP2 is a more conserved ligand than ghrelin towards fish GHSRs. Our results not only provided new insights into the interaction mechanism of GHSRs with LEAP2s and ghrelins, but also shed new light on the functions of LEAP2 and ghrelin in different fish species.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Fen Wang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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7
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Wada R, Takemi S, Matsumoto M, Iijima M, Sakai T, Sakata I. Molecular cloning and analysis of the ghrelin/GHSR system in Xenopus tropicalis. Gen Comp Endocrinol 2023; 331:114167. [PMID: 36402245 DOI: 10.1016/j.ygcen.2022.114167] [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: 04/12/2022] [Revised: 10/16/2022] [Accepted: 11/12/2022] [Indexed: 11/18/2022]
Abstract
Ghrelin is a gut-derived peptide with several physiological functions, including feeding, gastrointestinal motility, and hormonal secretion. Recently, a host defense peptide, liver-expressed antimicrobial peptide-2 (LEAP2), was reported as an endogenous antagonist of growth hormone secretagogue receptor (GHS-R). The physiological relevance of the molecular LEAP2-GHS-R interaction in mammals has been explored; however, studies on non-mammals are limited. Here, we report the identification and functional characterization of ghrelin and its related molecules in Western clawed frog (Xenopus tropicalis), a known model organism. We first identified cDNA encoding X. tropicalis ghrelin and GHS-R. RT-qPCR revealed that ghrelin mRNA expression was most abundant in the stomach. GHS-R mRNA was widely distributed in the brain and peripheral tissues, and a relatively strong signal was observed in the stomach and intestine. In addition, LEAP2 was mainly expressed in intestinal tissues at higher levels than in the liver. In functional analysis, X. tropicalis ghrelin and human ghrelin induced intracellular Ca2+ mobilization with EC50 values in the low nanomolar range in CHO-K1 cells expressing X. tropicalis GHS-R. Furthermore, ghrelin-induced GHS-R activation was antagonized with IC50 values in the nanomolar range by heterologous human LEAP2. We also validated the expression of ghrelin and feeding-related factors under fasting conditions. After 2 days of fasting, no changes in ghrelin mRNA levels were observed in the stomach, but GHS-R mRNA levels were significantly increased, associated with significant downregulation of nucb2. In addition, LEAP2 upregulation was observed in the duodenum. These results provide the first evidence that LEAP2 functions as an antagonist of GHS-R in the anuran amphibian X. tropicalis. It has also been suggested that the ghrelin/GHS-R/LEAP2 system may be involved in energy homeostasis in X. tropicalis.
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Affiliation(s)
- Reiko Wada
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Shota Takemi
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Mio Matsumoto
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Mio Iijima
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan
| | - Takafumi Sakai
- Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Ichiro Sakata
- Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakuraku, Saitama 338-8570, Japan.
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8
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Chicken LEAP2 Level Substantially Changes with Feed Intake and May Be Regulated by CDX4 in Small Intestine. Animals (Basel) 2022; 12:ani12243496. [PMID: 36552416 PMCID: PMC9774203 DOI: 10.3390/ani12243496] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Ghrelin O-acyltransferase (GOAT), ghrelin, and GHSR have been reported to play important roles that influence feed intake in mammals. LEAP2, an endogenous antagonist of GHSR, plays an important role in the regulation of feed intake. However, chicken ghrelin has also been reported to have an inhibitory effect on feed intake. The role of the GOAT-Ghrelin-GHSR-LEAP2 axis in chicken-feed intake remains unclear. Therefore, it is necessary to systematically evaluate the changes in the tissue expression levels of these genes under different energy states. In this study, broiler chicks in different energy states were subjected to starvation and feeding, and relevant gene expression levels were measured using quantitative real-time PCR. Different energy states significantly modulated the expression levels of LEAP2 and GHSR but did not significantly affect the expression levels of GOAT and ghrelin. A high expression level of LEAP2 was detected in the liver and the whole small intestine. Compared to the fed group, the fasted chicks showed significantly reduced LEAP2 expression levels in the liver and the small intestine; 2 h after being refed, the LEAP2 expression of the fasted chicks returned to the level of the fed group. Transcription factor prediction and results of a dual luciferase assay indicated that the transcription factor CDX4 binds to the LEAP2 promoter region and positively regulates its expression. High expression levels of GHSR were detected in the hypothalamus and pituitary. Moreover, we detected GHSR highly expressed in the jejunum-this finding has not been previously reported. Thus, GHSR may regulate intestinal motility, and this aspect needs further investigation. In conclusion, this study revealed the function of chicken LEAP2 as a potential feed-intake regulator and identified the potential mechanism governing its intestine-specific expression. Our study lays the foundations for future studies on avian feed-intake regulation.
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9
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Li HZ, Shao XX, Shou LL, Li N, Liu YL, Xu ZG, Guo ZY. Development of Esterase-Resistant and Highly Active Ghrelin Analogs via Thiol-Ene Click Chemistry. ACS Med Chem Lett 2022; 13:1655-1662. [PMID: 36262400 PMCID: PMC9575166 DOI: 10.1021/acsmedchemlett.2c00339] [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: 07/22/2022] [Accepted: 09/27/2022] [Indexed: 11/29/2022] Open
Abstract
The orexigenic peptide ghrelin exerts important functions in energy metabolism and has therapeutic potential to treat certain diseases. Native ghrelin carries an essential O-fatty acyl moiety; however, this post-translational modification is susceptible to hydrolysis by certain esterases in circulation, representing a major route of its in vivo inactivation. In the present study, we developed a novel approach to prepare various esterase-resistant ghrelin analogs via photoinduced thiol-ene click chemistry. A recombinant unacylated human ghrelin mutant was reacted with commercially available terminal alkenes; thus, various alkyl moieties were introduced to the side chain of its unique Cys3 residue via a thioether bond. Among 11 S-alkylated ghrelin analogs, analog 11, generated by reacting with 2-methyl-1-octene, not only acquired much higher stability in serum but also retained full activity compared with native human ghrelin. Thus, the present study provided an efficient approach to prepare highly stable and highly active ghrelin analogs with therapeutic potential.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Li-Li Shou
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Ning Li
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Ya-Li Liu
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine
at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
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10
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Liu YL, Guo ZY. The NanoBiT-Based Homogenous Ligand-Receptor Binding Assay. Methods Mol Biol 2022; 2525:139-153. [PMID: 35836065 DOI: 10.1007/978-1-0716-2473-9_10] [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] [Indexed: 06/15/2023]
Abstract
NanoLuc Binary Technology (NanoBiT) was recently developed by Promega, based on a large NanoLuc fragment (LgBiT) and two small complementation tags, the low-affinity SmBiT tag and the high-affinity HiBiT tag. In recent studies, we applied NanoBiT to ligand-binding assays of some G protein-coupled receptors via genetic fusion of a secretory LgBiT (sLgBiT) to the extracellular N-terminus of the receptors and covalent attachment of the low-affinity SmBiT tag to an appropriate position of their peptide ligands. The NanoBiT-based homogenous ligand-receptor binding assay is convenient for use and suitable for both the wild-type and mutant receptors, representing a novel tool for interaction mechanism studies of these receptors with their ligands. In the present chapter, we provide detailed protocols for setting up the NanoBiT-based homogenous binding assay using growth hormone secretagogue receptor type 1a (GHSR1a) and its endogenous agonist and antagonist as a representative model system.
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Affiliation(s)
- Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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11
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Li HZ, Shou LL, Shao XX, Li N, Liu YL, Xu ZG, Guo ZY. LEAP2 has antagonized the ghrelin receptor GHSR1a since its emergence in ancient fish. Amino Acids 2021; 53:939-949. [PMID: 33966114 DOI: 10.1007/s00726-021-02998-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 05/03/2021] [Indexed: 11/30/2022]
Abstract
Recent studies have demonstrated that liver-expressed antimicrobial peptide 2 (LEAP2) antagonizes the ghrelin receptor GHSR1a in mammals. However, its antagonistic function in lower vertebrates has not yet been tested. LEAP2 orthologs have been identified from a variety of fish species; however, previous studies all focused on their antimicrobial activity. To test whether LEAP2 functions as a GHSR1a antagonist in the lowest vertebrates, we studied the antagonism of a fish LEAP2 from Latimeria chalumnae, an extant coelacanth that is one of the closest living fish relatives of tetrapods. Using binding assays, we demonstrated that the coelacanth LEAP2 and ghrelin bound to the coelacanth GHSR1a with IC50 values in the nanomolar range. Using activation assays, we demonstrated that the coelacanth ghrelin activated the coelacanth GHSR1a with an EC50 value in the nanomolar range, and this activation effect was efficiently antagonized by a nanomolar range of the coelacanth LEAP2. In addition, we also showed that the human LEAP2 and ghrelin were as effective as their coelacanth orthologs towards the coelacanth GHSR1a; however, the coelacanth peptides had moderately lower activity towards the human GHSR1a. Thus, LEAP2 serves as an endogenous antagonist of the ghrelin receptor GHSR1a in coelacanth and the ghrelin-LEAP2-GHSR1a system has evolved slowly since its emergence in ancient fish.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Li-Li Shou
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Ning Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
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Li HZ, Shao XX, Shou LL, Li N, Liu YL, Xu ZG, Guo ZY. Unusual orthologs shed new light on the binding mechanism of ghrelin to its receptor GHSR1a. Arch Biochem Biophys 2021; 704:108872. [PMID: 33857472 DOI: 10.1016/j.abb.2021.108872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/23/2021] [Accepted: 04/06/2021] [Indexed: 01/18/2023]
Abstract
The gastric peptide ghrelin has important functions in energy metabolism and cellular homeostasis by activating growth hormone secretagogue receptor type 1a (GHSR1a). The N-terminal residues of ghrelin orthologs from all vertebrates are quite conserved; however, in orthologs from Cavia porcellus and Phyllostomus discolor, Ser2 and Leu5 are replaced by a smaller Ala and a positively charged Arg, respectively. In the present study, we first demonstrated that the hydrophobic Leu5 is essential for the function of human ghrelin, because Ala replacement caused an approximately 100-fold decrease in activity. However, replacement of Leu5 by an Arg residue caused much less disruption; further replacement of Ser2 by Ala almost restored full activity, although the [S2A] mutation itself showed slight detriments, implying that the positively charged Arg5 in the [S2A,L5R] mutant might form alternative interactions with certain receptor residues to compensate for the loss of the essential Leu5. To identify the responsible receptor residues, we screened GHSR1a mutants in which all conserved negatively charged residues in the extracellular regions and all aromatic residues in the ligand-binding pocket were mutated separately. According to the decrease in selectivity of the mutant receptors towards [S2A,L5R]ghrelin, we deduced that the positively charged Arg5 of the ghrelin mutant primarily interacts with the essential aromatic Phe286 at the extracellular end of the sixth transmembrane domain of GHSR1a by forming cation-π and π-π interactions. The present study provided new insights into the binding mechanism of ghrelin with its receptor, and thus would facilitate the design of novel ligands for GHSR1a.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Li-Li Shou
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ning Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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13
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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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Lu X, Huang L, Huang Z, Feng D, Clark RJ, Chen C. LEAP-2: An Emerging Endogenous Ghrelin Receptor Antagonist in the Pathophysiology of Obesity. Front Endocrinol (Lausanne) 2021; 12:717544. [PMID: 34512549 PMCID: PMC8428150 DOI: 10.3389/fendo.2021.717544] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/28/2021] [Indexed: 11/20/2022] Open
Abstract
Liver-expressed antimicrobial peptide 2 (LEAP-2), originally described as an antimicrobial peptide, has recently been recognized as an endogenous blocker of growth hormone secretagogue receptor 1a (GHS-R1a). GHS-R1a, also known as ghrelin receptor, is a G protein-coupled receptor (GPCR) widely distributed on the hypothalamus and pituitary gland where it exerts its major functions of regulating appetite and growth hormone (GH) secretion. The activity of GHS-R1a is controlled by two counter-regulatory endogenous ligands: Ghrelin (activation) and LEAP-2 (inhibition). Ghrelin activates GHS-R1a on the neuropeptide Y/Agouti-related protein (NPY/AgRP) neurons at the arcuate nucleus (ARC) to promote appetite, and on the pituitary somatotrophs to stimulate GH release. On the flip side, LEAP-2, acts both as an endogenous competitive antagonist of ghrelin and an inverse agonist of constitutive GHS-R1a activity. Such a biological property of LEAP-2 vigorously blocks ghrelin's effects on food intake and hormonal secretion. In circulation, LEAP-2 displays an inverse pattern as to ghrelin; it increases with food intake and obesity (positive energy balance), whereas decreases upon fasting and weight loss (negative energy balance). Thus, the LEAP-2/ghrelin molar ratio fluctuates in response to energy status and modulation of this ratio conversely influences energy intake. Inhibiting ghrelin's activity has shown beneficial effects on obesity in preclinical experiments, which sheds light on LEAP-2's anti-obesity potential. In this review, we will analyze LEAP-2's effects from a metabolic point of view with a focus on metabolic hormones (e.g., ghrelin, GH, and insulin), and discuss LEAP-2's potential as a promising therapeutic target for obesity.
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Affiliation(s)
- Xuehan Lu
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Lili Huang
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Zhengxiang Huang
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Dandan Feng
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
- Department of Physiology, Xiangya Medical School, Central South University, Changsha, China
| | - Richard J. Clark
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
- *Correspondence: Chen Chen,
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