{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T20:06:47Z","timestamp":1791490007869,"version":"4.3.4"},"reference-count":33,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T00:00:00Z","timestamp":1756857600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"special project of Guangdong Province for the transformation of science and technology to promote the regional coordinated development of urban-rural","award":["2025B0202010041"],"award-info":[{"award-number":["2025B0202010041"]}]},{"name":"special project of Guangdong Province for the transformation of science and technology to promote the regional coordinated development of urban-rural","award":["TJAE201506"],"award-info":[{"award-number":["TJAE201506"]}]},{"name":"special project of Guangdong Province for the transformation of science and technology to promote the regional coordinated development of urban-rural","award":["KCXFZ20211020165547010"],"award-info":[{"award-number":["KCXFZ20211020165547010"]}]},{"name":"special project of Guangdong Province for the transformation of science and technology to promote the regional coordinated development of urban-rural","award":["1303"],"award-info":[{"award-number":["1303"]}]},{"name":"Open Fund of Tianjin Key Lab of aquatic ecology and aquaculture","award":["2025B0202010041"],"award-info":[{"award-number":["2025B0202010041"]}]},{"name":"Open Fund of Tianjin Key Lab of aquatic ecology and aquaculture","award":["TJAE201506"],"award-info":[{"award-number":["TJAE201506"]}]},{"name":"Open Fund of Tianjin Key Lab of aquatic ecology and aquaculture","award":["KCXFZ20211020165547010"],"award-info":[{"award-number":["KCXFZ20211020165547010"]}]},{"name":"Open Fund of Tianjin Key Lab of aquatic ecology and aquaculture","award":["1303"],"award-info":[{"award-number":["1303"]}]},{"name":"Shenzhen Science and Technology Program","award":["2025B0202010041"],"award-info":[{"award-number":["2025B0202010041"]}]},{"name":"Shenzhen Science and Technology Program","award":["TJAE201506"],"award-info":[{"award-number":["TJAE201506"]}]},{"name":"Shenzhen Science and Technology Program","award":["KCXFZ20211020165547010"],"award-info":[{"award-number":["KCXFZ20211020165547010"]}]},{"name":"Shenzhen Science and Technology Program","award":["1303"],"award-info":[{"award-number":["1303"]}]},{"name":"Shenzhen Industrial Development Special Fund Project","award":["2025B0202010041"],"award-info":[{"award-number":["2025B0202010041"]}]},{"name":"Shenzhen Industrial Development Special Fund Project","award":["TJAE201506"],"award-info":[{"award-number":["TJAE201506"]}]},{"name":"Shenzhen Industrial Development Special Fund Project","award":["KCXFZ20211020165547010"],"award-info":[{"award-number":["KCXFZ20211020165547010"]}]},{"name":"Shenzhen Industrial Development Special Fund Project","award":["1303"],"award-info":[{"award-number":["1303"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Liver-expressed antimicrobial peptide 2 (LEAP2) is a cationic peptide that is integral to the innate immune system. However, its regulatory function in the immunity of fish against pathogens remains largely unexplored. This study identifies a LEAP2 homolog (AoLEAP2) in clownfish, Amphiprion ocellaris. Our phylogenetic analysis places AoLEAP2 within the fish LEAP2 cluster, closely related to Tachinotus anak LEAP2. AoLEAP2 mRNA is present across various tissues, with the highest expression in the spleen. Following Vibrio harveyi infection, the AoLEAP2 mRNA levels significantly increased in the liver, spleen, gills, and intestine. The chemically synthesized AoLEAP2 mature peptide exhibits broad-spectrum antibacterial activity without displaying toxicity to FHM cells in vitro. The intraperitoneal injection of AoLEAP2 significantly suppresses the mRNA expression of the pro-inflammatory factors IL1\u03b2 and TNF\u03b1 induced by V. harveyi infection, demonstrating its anti-inflammatory and immune-regulatory role.<\/jats:p>","DOI":"10.3390\/ani15172590","type":"journal-article","created":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T15:15:57Z","timestamp":1756912557000},"page":"2590","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Molecular Characterization of the Liver-Expressed Antimicrobial Peptide 2 (LEAP2) from Amphiprion ocellaris and Its Role in Antibacterial Immunity"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4389-1224","authenticated-orcid":false,"given":"Dapeng","family":"Yu","sequence":"first","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tao","family":"Li","sequence":"additional","affiliation":[{"name":"Shenzhen Base of South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shenzhen 518121, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kang","family":"Wang","sequence":"additional","affiliation":[{"name":"Jiangsu Lianshen Ocean Technology, Co., Ltd., Lianyungang 222000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meiling","family":"Zhang","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingyi","family":"Mo","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianlin","family":"Chen","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongli","family":"Xia","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yishan","family":"Lu","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9501-7336","authenticated-orcid":false,"given":"Jia","family":"Cai","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China"},{"name":"Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 518108, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1186\/s12967-025-06321-9","article-title":"Antimicrobial Peptide Biological Activity, Delivery Systems and Clinical Translation Status and Challenges","volume":"23","author":"Zheng","year":"2025","journal-title":"J. Transl. Med."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Odunitan, T.T., Apanisile, B.T., Afolabi, J.A., Adeniwura, P.O., Akinboade, M.W., Ibrahim, N.O., Alare, K.P., Saibu, O.A., Adeosun, O.A., and Opeyemi, H.S. (2025). Beyond Conventional Drug Design: Exploring the Broad-Spectrum Efficacy of Antimicrobial Peptides. Chem. Biodivers., 22.","DOI":"10.1002\/cbdv.202401349"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"104305","DOI":"10.1016\/j.drudis.2025.104305","article-title":"Antimicrobial Peptides: An Alternative Strategy to Combat Antimicrobial Resistance","volume":"30","author":"Gani","year":"2025","journal-title":"Drug Discov. Today"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2058","DOI":"10.1007\/s12602-024-10430-0","article-title":"Antimicrobial Peptides Against Arboviruses: Mechanisms, Challenges, and Future Directions","volume":"17","author":"Owliaee","year":"2025","journal-title":"Probiotics Antimicrob. Proteins"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1080\/10826068.2024.2365357","article-title":"Antimicrobial Peptides (AMPs) from Microalgae as an Alternative to Conventional Antibiotics in Aquaculture","volume":"55","author":"Merlano","year":"2025","journal-title":"Prep. Biochem. Biotechnol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"112442","DOI":"10.1016\/j.mce.2024.112442","article-title":"Simultaneous Treatment with Palm-LEAP2(1-14) and Feeding High-Fat Diet Attenuates Liver Lipid Metabolism but Not Obesity: Sign of Selective Resistance to Palm-LEAP2(1-14)","volume":"597","author":"Cantel","year":"2025","journal-title":"Mol. Cell Endocrinol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"101996","DOI":"10.1016\/j.xcrm.2025.101996","article-title":"Regulation of LEAP2 by Insulin and Glucagon in Mice and Humans","volume":"6","author":"Johansen","year":"2025","journal-title":"Cell Rep. Med."},{"key":"ref_8","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_9","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1016\/j.fsi.2013.05.021","article-title":"Molecular Cloning and Expression Analysis of Liver-Expressed Antimicrobial Peptide 1 (LEAP-1) and LEAP2 Genes in the Blunt Snout Bream (Megalobrama amblycephala)","volume":"35","author":"Liang","year":"2013","journal-title":"Fish Shellfish Immunol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1016\/j.fsi.2014.04.004","article-title":"Molecular Characterization and Functional Analysis of Two Distinct Liver-Expressed Antimicrobial Peptide 2 (LEAP2) Genes in Large Yellow Croaker (Larimichthys crocea)","volume":"38","author":"Li","year":"2014","journal-title":"Fish Shellfish Immunol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.vetimm.2009.07.014","article-title":"Molecular Cloning and Expression Analysis of the Liver-Expressed Antimicrobial Peptide 2 (LEAP2) Gene in Grass Carp","volume":"133","author":"Liu","year":"2010","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/j.fsi.2014.08.010","article-title":"Characterization, Evolution and Functional Analysis of the Liver-Expressed Antimicrobial Peptide 2 (LEAP2) Gene in Miiuy Croaker","volume":"41","author":"Liu","year":"2014","journal-title":"Fish Shellfish Immunol."},{"key":"ref_13","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_14","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1016\/j.ijantimicag.2004.09.005","article-title":"Antimicrobial Peptides: Premises and Promises","volume":"24","author":"Reddy","year":"2004","journal-title":"Int. J. Antimicrob. Agents"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1016\/j.peptides.2012.06.001","article-title":"Importance of the Disulfide Bridges in the Antibacterial Activity of Human Hepcidin","volume":"36","author":"Hocquellet","year":"2012","journal-title":"Peptides"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.peptides.2009.10.006","article-title":"Structure\u2013Activity Relationship of Human Liver-Expressed Antimicrobial Peptide 2","volume":"31","author":"Hocquellet","year":"2010","journal-title":"Peptides"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.peptides.2016.06.008","article-title":"Overexpression of Leap2 Impairs Xenopus Embryonic Development and Modulates FGF and Activin Signals","volume":"83","author":"Garbay","year":"2016","journal-title":"Peptides"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1016\/j.vetimm.2004.05.005","article-title":"Discovery and Characterization of Two Types of Liver-Expressed Antimicrobial Peptide 2 (LEAP2) Genes in Rainbow Trout","volume":"101","author":"Zhang","year":"2004","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1016\/j.fsi.2019.08.054","article-title":"Antimicrobial Activity and Mechanisms of Multiple Antimicrobial Peptides Isolated from Rockfish Sebastiscus marmoratus","volume":"93","author":"Bo","year":"2019","journal-title":"Fish Shellfish Immunol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1110\/ps.0213603","article-title":"Isolation and Biochemical Characterization of LEAP2, a Novel Blood Peptide Expressed in the Liver","volume":"12","author":"Krause","year":"2003","journal-title":"Protein Sci."},{"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":"965","DOI":"10.1021\/acs.jmedchem.8b01644","article-title":"N-Terminal Liver-Expressed Antimicrobial Peptide 2 (LEAP2) Region Exhibits Inverse Agonist Activity toward the Ghrelin Receptor","volume":"62","author":"Cabral","year":"2019","journal-title":"J. Med. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1016\/j.molimm.2015.02.022","article-title":"Molecular Characterization of the Liver-Expressed Antimicrobial Peptide 2 (LEAP2) in a Teleost Fish, Plecoglossus altivelis: Antimicrobial Activity and Molecular Mechanism","volume":"65","author":"Li","year":"2015","journal-title":"Mol. Immunol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.fsi.2016.10.028","article-title":"The Protection Effect of LEAP2 on the Mudskipper (Boleophthalmus pectinirostris) against Edwardsiella Tarda Infection Is Associated with Its Immunomodulatory Activity on Monocytes\/Macrophages","volume":"59","author":"Chen","year":"2016","journal-title":"Fish Shellfish Immunol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"644","DOI":"10.24272\/j.issn.2095-8137.2020.211","article-title":"MOSPD2 Is a Receptor Mediating the LEAP2 Effect on Monocytes\/Macrophages in a Teleost, Boleophthalmus pectinirostris","volume":"41","author":"Li","year":"2020","journal-title":"Zool. Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1186\/s13227-020-00166-7","article-title":"Anemonefish, a Model for Eco-Evo-Devo","volume":"11","author":"Roux","year":"2020","journal-title":"Evodevo"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"104168","DOI":"10.1016\/j.dci.2021.104168","article-title":"Expression Profiling, Immune Functions, and Molecular Characteristics of the Tetraspanin Molecule CD63 from Amphiprion clarkii","volume":"123","author":"Liyanage","year":"2021","journal-title":"Dev. Comp. Immunol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"738321","DOI":"10.1016\/j.aquaculture.2022.738321","article-title":"Study on the Expression of Nk-Lysin from Nile Tilapia (Oreochromis niloticus) in Pichia pastoris and Its Biological Function","volume":"557","author":"Chen","year":"2022","journal-title":"Aquaculture"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Pepi, M., and Focardi, S. (2021). Antibiotic-Resistant Bacteria in Aquaculture and Climate Change: A Challenge for Health in the Mediterranean Area. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18115723"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Zhang, M., Li, M., and Sun, L. (2014). NKLP27: A Teleost NK-Lysin Peptide That Modulates Immune Response, Induces Degradation of Bacterial DNA, and Inhibits Bacterial and Viral Infection. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0106543"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Chen, J., Zhang, C.-Y., Chen, J.-Y., Seah, R.W.X., Zhang, L., Ma, L., and Ding, G.-H. (2023). Host Defence Peptide LEAP2 Contributes to Antimicrobial Activity in a Mustache Toad (Leptobrachium liui). BMC Vet. Res., 19.","DOI":"10.1186\/s12917-023-03606-3"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"878","DOI":"10.1016\/j.fsi.2015.10.031","article-title":"Cathelicidin Modulates the Function of Monocytes\/Macrophages via the P2X7 Receptor in a Teleost, Plecoglossus altivelis","volume":"47","author":"Li","year":"2015","journal-title":"Fish Shellfish Immunol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"984","DOI":"10.1016\/j.jaci.2016.06.033","article-title":"Interleukins (from IL-1 to IL-38), Interferons, Transforming Growth Factor \u03b2, and TNF-\u03b1: Receptors, Functions, and Roles in Diseases","volume":"138","author":"Akdis","year":"2016","journal-title":"J. Allergy Clin. Immunol."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/17\/2590\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:38:56Z","timestamp":1760035136000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/17\/2590"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,3]]},"references-count":33,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["ani15172590"],"URL":"https:\/\/doi.org\/10.3390\/ani15172590","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,3]]}}}