title: Corticotropin-releasing hormone (CRH) stimulates cocaine- and amphetamine-regulated transcript gene (CART1) expression through CRH type 1 receptor (CRHR1) in chicken anterior pituitary.
abstract: Cocaine- and amphetamine-regulated transcript (CART) peptide(s) is generally viewed as neuropeptide(s) and can control food intake in vertebrates, however, our recent study revealed that CART1 peptide is predominantly expressed in chicken anterior pituitary, suggesting that cCART1 peptide is a novel pituitary hormone in chickens and its expression is likely controlled by hypothalamic factor(s). To test this hypothesis, in this study, we examined the spatial expression of CART1 in chicken anterior pituitary and investigated the effect of hypothalamic corticotropin-releasing hormone (CRH) on pituitary cCART1 expression. The results showed that: 1) CART1 is expressed in both caudal and cephalic lobes of chicken anterior pituitary, revealed by quantitative real-time PCR (qPCR), western blot and immuno-histochemical staining; 2) CRH potently stimulates cCART1 mRNA expression in cultured chick pituitary cells, as examined by qPCR, and this effect is blocked by CP154526 (and not K41498), an antagonist specific for chicken CRH type I receptor (cCRHR1), suggesting that cCRHR1 expressed on corticotrophs mediates this action; 3) the stimulatory effect of CRH on pituitary cCART1 expression is inhibited by pharmacological drugs targeting the intracellular AC/cAMP/PKA, PLC/IP3/Ca(2+), and MEK/ERK signaling pathways. This finding, together with the functional coupling of these signaling pathways to cCRHR1 expressed in CHO cells demonstrated by luciferase reporter assay systems, indicates that these intracellular signaling pathways coupled to cCRHR1 can mediate CRH action. Collectively, our present study offers the first substantial evidence that hypothalamic CRH can stimulate pituitary CART1 expression via activation of CRHR1 in a vertebrate species.
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, 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 610065, PR China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Cai
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, PR China.
authors.forename: Long
authors.initials: L
authors.lastname: Huang
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, PR China.
authors.forename: Qiuyang
authors.initials: Q
authors.lastname: Deng
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, 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 610065, 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 610065, PR China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, PR China. Electronic address: lijuanscuhk@163.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D002645:Chickens; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D003412:Cricetulus; D005786:Gene Expression Regulation / Q000187:drug effects; D020935:MAP Kinase Signaling System / Q000187:drug effects; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism*; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; D000099052:CRF Receptor, Type 1
chemical_list: D009419:Nerve Tissue Proteins; D018019:Receptors, Corticotropin-Releasing Hormone; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; D000099052:CRF Receptor, Type 1; D003346:Corticotropin-Releasing Hormone
keywords: CART; CRHR1; CRHR2; Chicken; Corticotropin-releasing hormone (CRH); Pituitary