{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T15:13:44Z","timestamp":1787498024208,"version":"build-2736575974"},"reference-count":52,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2022,12,11]],"date-time":"2022-12-11T00:00:00Z","timestamp":1670716800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004608","name":"Natural Science Foundation of Jiangsu Province","doi-asserted-by":"publisher","award":["BK20220648"],"award-info":[{"award-number":["BK20220648"]}],"id":[{"id":"10.13039\/501100004608","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>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\u2013Ghrelin\u2013GHSR\u2013LEAP2 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\u2014this 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.<\/jats:p>","DOI":"10.3390\/ani12243496","type":"journal-article","created":{"date-parts":[[2022,12,12]],"date-time":"2022-12-12T03:36:09Z","timestamp":1670816169000},"page":"3496","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Chicken LEAP2 Level Substantially Changes with Feed Intake and May Be Regulated by CDX4 in Small Intestine"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5531-3843","authenticated-orcid":false,"given":"Xiaotong","family":"Zheng","sequence":"first","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ziwei","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wuchao","family":"Zhuang","sequence":"additional","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jilong","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiaheng","family":"He","sequence":"additional","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yinku","family":"Xie","sequence":"additional","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6575-4493","authenticated-orcid":false,"given":"Jianfei","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"656","DOI":"10.1038\/45230","article-title":"Ghrelin is a growth-hormone-releasing acylated peptide from stomach","volume":"402","author":"Kojima","year":"1999","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1038\/35051587","article-title":"A role for ghrelin in the central regulation of feeding","volume":"409","author":"Nakazato","year":"2001","journal-title":"Nature"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1097\/MCO.0b013e328365b9be","article-title":"Ghrelin: Much more than a hunger hormone","volume":"16","author":"Pradhan","year":"2013","journal-title":"Curr. Opin. Clin. Nutr. Metab. Care"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1016\/j.cell.2008.01.017","article-title":"Identification of the acyltransferase that octanoylates ghrelin, an appetite-stimulating peptide hormone","volume":"132","author":"Yang","year":"2008","journal-title":"Cell"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"6320","DOI":"10.1073\/pnas.0800708105","article-title":"Ghrelin octanoylation mediated by an orphan lipid transferase","volume":"105","author":"Gutierrez","year":"2008","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1530\/EJE-10-0099","article-title":"GOAT: The master switch for the ghrelin system?","volume":"163","author":"Romero","year":"2010","journal-title":"Eur. J. Endocrinol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1007\/s11427-015-4973-6","article-title":"Ghrelin O-acyltransferase (GOAT) and energy metabolism","volume":"59","author":"Li","year":"2016","journal-title":"Sci. China Life Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1220","DOI":"10.1006\/bbrc.2001.4518","article-title":"Upregulation of Ghrelin Expression in the Stomach upon Fasting, Insulin-Induced Hypoglycemia, and Leptin Administration","volume":"281","author":"Toshinai","year":"2001","journal-title":"Biochem. Bioph. Res. Co."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/S0014-2999(02)02393-2","article-title":"Chicken ghrelin and growth hormone-releasing peptide-2 inhibit food intake of neonatal chicks","volume":"453","author":"Saito","year":"2002","journal-title":"Eur. J. Pharmacol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2305","DOI":"10.3382\/ps.2012-02206","article-title":"The effect of passive immunization against ghrelin on feed and water intake in turkeys1","volume":"91","author":"Vizcarra","year":"2012","journal-title":"Poultry Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.regpep.2004.09.003","article-title":"Inhibitory effect of ghrelin on food intake is mediated by the corticotropin-releasing factor system in neonatal chicks","volume":"125","author":"Saito","year":"2005","journal-title":"Regul. Pept."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.domaniend.2006.03.006","article-title":"Changes in ghrelin levels of plasma and proventriculus and ghrelin mRNA of proventriculus in fasted and refed layer chicks","volume":"32","author":"Kaiya","year":"2007","journal-title":"Domest. Anim. Endocrin."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/j.ygcen.2004.12.021","article-title":"Different effects of peripheral and central ghrelin on regulation of food intake in the Japanese quail","volume":"141","author":"Shousha","year":"2005","journal-title":"Gen. Comp. Endocr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1110\/ps.0213603","article-title":"Isolation and biochemical characterization of LEAP-2, a novel blood peptide expressed in the liver","volume":"12","author":"Krause","year":"2003","journal-title":"Protein Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"973","DOI":"10.1017\/S0022215107006184","article-title":"Expression and immunolocalisation of antimicrobial peptides within human palatine tonsils","volume":"121","author":"Ball","year":"2007","journal-title":"J. Laryngol. Otol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1016\/j.cmet.2017.10.016","article-title":"LEAP2 is an Endogenous Antagonist of the Ghrelin Receptor","volume":"27","author":"Ge","year":"2018","journal-title":"Cell Metab."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3542","DOI":"10.1172\/JCI131023","article-title":"The next big LEAP2 understanding ghrelin function","volume":"129","author":"Andrews","year":"2019","journal-title":"J. Clin. Investig."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3909","DOI":"10.1172\/JCI125332","article-title":"LEAP2 changes with body mass and food intake in humans and mice","volume":"129","author":"Mani","year":"2019","journal-title":"J. Clin. Investig."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.cellimm.2009.11.010","article-title":"Expression and functional analyses of liver expressed antimicrobial peptide-2 (LEAP-2) variant forms in human tissues","volume":"261","author":"Howard","year":"2010","journal-title":"Cell. Immunol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1530\/JOE-19-0102","article-title":"Liver-expressed antimicrobial peptide 2 antagonizes the effect of ghrelin in rodents","volume":"244","author":"Islam","year":"2020","journal-title":"J. Endocrinol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3199","DOI":"10.1042\/BCJ20200228","article-title":"Identifying key residues and key interactions for the binding of LEAP2 to receptor GHSR1a","volume":"477","author":"Li","year":"2020","journal-title":"Biochem. J."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"500","DOI":"10.1016\/j.bbrc.2009.07.046","article-title":"The interaction of the antimicrobial peptide cLEAP-2 and the bacterial membrane","volume":"387","author":"Townes","year":"2009","journal-title":"Biochem. Bioph. Res. Co."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2421","DOI":"10.3382\/ps\/pew468","article-title":"Expression of host defense peptides in the intestine of Eimeria-challenged chickens","volume":"96","author":"Su","year":"2017","journal-title":"Poult. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Niu, S., Jahejo, A.R., Jia, F., Li, X., Ning, G., Zhang, D., Ma, H., Hao, W., Gao, W., and Zhao, Y. (2018). Transcripts of antibacterial peptides in chicken erythrocytes infected with Marek\u2019s disease virus. BMC Vet. Res., 14.","DOI":"10.1186\/s12917-018-1678-7"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Jang, H., Monson, M., Kaiser, M., and Lamont, S.J. (2020). Induction of Chicken Host Defense Peptides within Disease-Resistant and -Susceptible Lines. Genes, 11.","DOI":"10.3390\/genes11101195"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1007\/s00251-004-0675-0","article-title":"Bioinformatic discovery and initial characterisation of nine novel antimicrobial peptide genes in the chicken","volume":"56","author":"Lynn","year":"2004","journal-title":"Immunogenetics"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1007\/s11259-010-9420-3","article-title":"Expression of chicken LEAP-2 in the reproductive organs and embryos and in response to Salmonella enterica infection","volume":"34","author":"Michailidis","year":"2010","journal-title":"Vet. Res. Commun."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3454","DOI":"10.1210\/en.2002-220255","article-title":"Chicken Ghrelin: Purification, cDNA Cloning, and Biological Activity","volume":"143","author":"Kaiya","year":"2002","journal-title":"Endocrinology"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/S0016-6480(03)00250-8","article-title":"Distribution and regulation of chicken growth hormone secretagogue receptor isoforms","volume":"134","author":"Geelissen","year":"2003","journal-title":"Gen. Comp. Endocrinol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.ygcen.2018.11.017","article-title":"Ghrelin serves as a signal of energy utilization and is involved in maintaining energy homeostasis in broilers","volume":"272","author":"Song","year":"2019","journal-title":"Gen. Comp. Endocr."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1016\/j.domaniend.2006.02.006","article-title":"An 8bp indel in exon 1 of Ghrelin gene associated with chicken growth","volume":"32","author":"Fang","year":"2007","journal-title":"Domest. Anim. Endocrin."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1007\/s11033-009-9556-9","article-title":"Associations of GHSR gene polymorphisms with chicken growth and carcass traits","volume":"37","author":"Fang","year":"2010","journal-title":"Mol. Biol. Rep."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.peptides.2014.11.006","article-title":"Correlation of ghrelin concentration and ghrelin, ghrelin-O-acetyltransferase (GOAT) and growth hormone secretagogue receptor 1a mRNAs expression in the proventriculus and brain of the growing chicken","volume":"63","author":"Kitazawa","year":"2015","journal-title":"Peptides"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1038\/nprot.2008.73","article-title":"Analyzing real-time PCR data by the comparative C(T) method","volume":"3","author":"Schmittgen","year":"2008","journal-title":"Nat. Protoc."},{"key":"ref_35","first-page":"494","article-title":"Identification of Reliable Reference Genes for Quantification of MicroRNAs in Serum Samples of Sulfur Mustard-Exposed Veterans","volume":"17","author":"Gharbi","year":"2015","journal-title":"Cell J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1124\/pr.55.1.3","article-title":"International Union of Pharmacology. XXXVI. Current Status of the Nomenclature for Receptors for Corticotropin-Releasing Factor and Their Ligands","volume":"55","author":"Hauger","year":"2003","journal-title":"Pharmacol. Rev."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/S0092-8674(00)81865-6","article-title":"Targeted Disruption of the Melanocortin-4 Receptor Results in Obesity in Mice","volume":"88","author":"Huszar","year":"1997","journal-title":"Cell"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.npep.2015.07.005","article-title":"The central anorexigenic mechanism of adrenocorticotropic hormone involves the caudal hypothalamus in chicks","volume":"53","author":"Shipp","year":"2015","journal-title":"Neuropeptides"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/j.physbeh.2014.11.043","article-title":"Central administration of chicken growth hormone-releasing hormone decreases food intake in chicks","volume":"139","author":"Tachibana","year":"2015","journal-title":"Physiol. Behav."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1016\/0196-9781(84)90165-7","article-title":"Neuropeptide Y: A potent inducer of consummatory behavior in rats","volume":"5","author":"Levine","year":"1984","journal-title":"Peptides"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Chen, G., Yang, F., Wu, T., Jiang, J., and Zhou, W. (2016). The Stimulatory Effect of Cerebral Intraventricular Injection of cNPY on Precocial Feeding Behavior in Neonatal Chicks (Gallus domesticus). PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0153342"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1210\/en.2015-1634","article-title":"Identification of the Long-Sought Leptin in Chicken and Duck: Expression Pattern of the Highly GC-Rich Avian leptin Fits an Autocrine\/Paracrine Rather Than Endocrine Function","volume":"157","author":"Seroussi","year":"2016","journal-title":"Endocrinology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1016\/j.aggene.2016.04.001","article-title":"Identification of a GC-rich leptin gene in chicken","volume":"1","author":"Hron","year":"2016","journal-title":"Agri. Gene"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Seroussi, E., Pitel, F., Leroux, S., Morisson, M., Bornel\u00f6v, S., Miyara, S., Yosefi, S., Cogburn, L.A., Burt, D.W., and Anderson, L. (2017). Mapping of leptin and its syntenic genes to chicken chromosome 1p. BMC Genet., 18.","DOI":"10.1186\/s12863-017-0543-1"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1016\/j.ygcen.2005.09.013","article-title":"Characterization of turkey and chicken ghrelin genes, and regulation of ghrelin and ghrelin receptor mRNA levels in broiler chickens","volume":"145","author":"Richards","year":"2006","journal-title":"Gen. Comp. Endocr."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1113\/jphysiol.2003.040600","article-title":"Ghrelin Induces Fasted Motor Activity of the Gastrointestinal Tract in Conscious Fed Rats","volume":"550","author":"Fujino","year":"2003","journal-title":"J. Physiol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"278","DOI":"10.3389\/fendo.2019.00278","article-title":"Regulation of Gastrointestinal Motility by Motilin and Ghrelin in Vertebrates","volume":"10","author":"Kitazawa","year":"2019","journal-title":"Front. Endocrinol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"101327","DOI":"10.1016\/j.molmet.2021.101327","article-title":"LEAP2 deletion in mice enhances ghrelin\u2019s actions as an orexigen and growth hormone secretagogue","volume":"53","author":"Shankar","year":"2021","journal-title":"Mol. Metab."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1007\/s00726-021-02998-6","article-title":"LEAP2 has antagonized the ghrelin receptor GHSR1a since its emergence in ancient fish","volume":"53","author":"Li","year":"2021","journal-title":"Amino Acids"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Xiao, Y., Hughes, A.L., Ando, J., Matsuda, Y., Cheng, J.F., Skinner-Noble, D., and Zhang, G. (2004). A genome-wide screen identifies a single beta-defensin gene cluster in the chicken: Implications for the origin and evolution of mammalian defensins. BMC Genom., 5.","DOI":"10.1186\/1471-2164-5-56"},{"key":"ref_51","first-page":"7340","article-title":"A homeodomain protein related to caudal regulates intestine-specific gene transcription","volume":"14","author":"Suh","year":"1994","journal-title":"Mol. Cell. Biol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"21361","DOI":"10.1074\/jbc.M110261200","article-title":"Cloning of the Human Claudin-2 5\u2032-Flanking Region Revealed a TATA-less Promoter with Conserved Binding Sites in Mouse and Human for Caudal-related Homeodomain Proteins and Hepatocyte Nuclear Factor-1\u03b1","volume":"277","author":"Sakaguchi","year":"2002","journal-title":"J. Biol. Chem."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/12\/24\/3496\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:38:00Z","timestamp":1760146680000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/12\/24\/3496"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,11]]},"references-count":52,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["ani12243496"],"URL":"https:\/\/doi.org\/10.3390\/ani12243496","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,11]]}}}