title: Goldfish Leptin-AI and Leptin-AII: Function and Central Mechanism in Feeding Control.
abstract: In mammals, leptin is a peripheral satiety factor that inhibits feeding by regulating a variety of appetite-related hormones in the brain. However, most of the previous studies examining leptin in fish feeding were performed with mammalian leptins, which share very low sequence homologies with fish leptins. To elucidate the function and mechanism of endogenous fish leptins in feeding regulation, recombinant goldfish leptin-AI and leptin-AII were expressed in methylotrophic yeast and purified by immobilized metal ion affinity chromatography (IMAC). By intraperitoneal (IP) injection, both leptin-AI and leptin-AII were shown to inhibit the feeding behavior and to reduce the food consumption of goldfish in 2 h. In addition, co-treatment of leptin-AI or leptin-AII could block the feeding behavior and reduce the food consumption induced by neuropeptide Y (NPY) injection. High levels of leptin receptor (lepR) mRNA were detected in the hypothalamus, telencephalon, optic tectum and cerebellum of the goldfish brain. The appetite inhibitory effects of leptins were mediated by downregulating the mRNA levels of orexigenic NPY, agouti-related peptide (AgRP) and orexin and upregulating the mRNA levels of anorexigenic cocaine-amphetamine-regulated transcript (CART), cholecystokinin (CCK), melanin-concentrating hormone (MCH) and proopiomelanocortin (POMC) in different areas of the goldfish brain. Our study, as a whole, provides new insights into the functions and mechanisms of leptins in appetite control in a fish model.
authors.affiliation: College of Medicine, Foshan University, Foshan 528000, China. yanaifen@mail3.sysu.edu.cn.
authors.forename: Ai-Fen
authors.initials: AF
authors.lastname: Yan
authors.affiliation: CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. chan1010@scsio.ac.cn.|South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. chan1010@scsio.ac.cn.
authors.forename: Ting
authors.initials: T
authors.lastname: Chen
authors.affiliation: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China. chenss@connect.hku.hk.
authors.forename: Shuang
authors.initials: S
authors.lastname: Chen
authors.affiliation: CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. rosemary166@sina.com.|South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. rosemary166@sina.com.
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Ren
authors.affiliation: CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. hucq@scsio.ac.cn.|South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. hucq@scsio.ac.cn.
authors.forename: Chao-Qun
authors.initials: CQ
authors.lastname: Hu
authors.affiliation: CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. cym052065@163.com.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Cai
authors.affiliation: College of Medicine, Foshan University, Foshan 528000, China. 1115fang@sina.com.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.affiliation: College of Medicine, Foshan University, Foshan 528000, China. tangdsh@163.com.
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Tang
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D029941:Fish Proteins / Q000008:administration & dosage / Q000235:genetics / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006054:Goldfish / Q000502:physiology*; D020738:Leptin / Q000008:administration & dosage* / Q000235:genetics* / Q000494:pharmacology; D009478:Neuropeptide Y / Q000008:administration & dosage; D054411:Receptors, Leptin / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D020738:Leptin; D009478:Neuropeptide Y; D054411:Receptors, Leptin; D011994:Recombinant Proteins
keywords: appetite regulators; feeding control; gene regulation; goldfish; leptin; methylotrophic yeast