title: Characterization of melanin-concentrating hormone (MCH) and its receptor in chickens: Tissue expression, functional analysis, and fasting-induced up-regulation of hypothalamic MCH expression.
abstract: Melanin-concentrating hormone (MCH) is a neuropeptide expressed in the brain and exerts its actions through interaction with the two known G protein-coupled receptors, namely melanin-concentrating hormone receptor 1 and 2 (MCHR1 and MCHR2) in mammals. However, the information regarding the expression and functionality of MCH and MCHR(s) remains largely unknown in birds. In this study, using RT-PCR and RACE PCR, we amplified and cloned a MCHR1-like receptor, which is named cMCHR4 according to its evolutionary origin, and a MCHR2 from chicken brain. The cloned cMCHR4 was predicted to encode a receptor of 367 amino acids, which shares high amino acid identities with MCHR4 of ducks (90%), western painted turtles (85%), and coelacanths (77%), and a comparatively low identity to human MCHR1 (58%) and MCHR2 (38%), whereas chicken MCHR2 encodes a putative C-terminally truncated receptor and is likely a pseudogene. Using cell-based luciferase reporter assays or Western blot, we further demonstrated that chicken (and duck) MCHR4 could be potently activated by chicken MCH1-19, and its activation can elevate calcium concentration and activate MAPK/ERK and cAMP/PKA signaling pathways, indicating an important role of MCHR4 in mediating MCH actions in birds. Quantitative real-time PCR revealed that both cMCH and cMCHR4 mRNA are expressed in various brain regions including the hypothalamus, and cMCH expression in the hypothalamus of 3-week-old chicks could be induced by 36-h fasting, indicating that cMCH expression is correlated with energy balance. Taken together, characterization of chicken MCH and MCHR4 will aid to uncover the conserved roles of MCH across vertebrates.
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Cui
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Can
authors.initials: C
authors.lastname: Lv
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Jiannan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Chunheng
authors.initials: C
authors.lastname: Mo
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Dongliang
authors.initials: D
authors.lastname: Lin
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China. Electronic address: cdwyjhk@gmail.com.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D004372:Ducks / Q000235:genetics; D005215:Fasting; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D007028:Hypothalamic Hormones / Q000235:genetics* / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D008543:Melanins / Q000235:genetics* / Q000378:metabolism; D010907:Pituitary Hormones / Q000235:genetics* / Q000378:metabolism; D011979:Receptors, Pituitary Hormone / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D007028:Hypothalamic Hormones; D008543:Melanins; D010907:Pituitary Hormones; D011979:Receptors, Pituitary Hormone; C092274:melanin-concentrating hormone receptor; C019463:melanin-concentrating hormone
keywords: Chicken; Fasting; MCHR; Melanin-concentrating hormone