title: In vitro neuroendocrine effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the AhR-expressing hypothalamic rat GnV-3 cell line.
abstract: The aryl hydrocarbon receptor (AhR) is involved in a wide variety of biological and toxicological responses, including neuroendocrine signaling. Due to the complexity of neuroendocrine pathways in e.g. the hypothalamus and pituitary, there are limited in vitro models available despite the strong demand for such systems to study and predict neuroendocrine effects of chemicals. In this study, the applicability of the AhR-expressing rat hypothalamic GnV-3 cell line was investigated as a novel model to screen for neuroendocrine effects of AhR ligands using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as reference compound. The qRT-PCR analyses demonstrated the presence of several sets of neurotransmitter receptors in the GnV-3 cells. TCDD (10nM) altered neurotransmitter signaling by up-regulation of glutamate (Grik2), gamma-amino butyric acid (Gabra2) and serotonin (Ht2C) receptor mRNA levels. However, no significant changes in basal and serotonin-evoked intracellular Ca(2+) concentration ([Ca(2+)]i) or serotonin release were observed. On the other hand, TCDD de-regulated period circadian protein homolog 1 (Per1) and gonadotropin releasing hormone (Gnrh) mRNA levels within a 24-h time period. Both Per1 and Gnrh genes displayed a similar mRNA expression pattern in GnV-3 cells. Moreover, the involvement of AhR in TCDD-induced alteration of Neuropeptide Y (Npy) gene expression was found and confirmed by using siRNA targeted against Ahr in GnV-3 cells. Overall, the combined results demonstrate that GnV-3 cells may be a suitable model to predict some mechanisms of action and effects of AhR ligands in the hypothalamus.
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. K.A.Solak@uu.nl
authors.forename: K A
authors.initials: KA
authors.lastname: Solak
authors.forename: F M J
authors.initials: FM
authors.lastname: Wijnolts
authors.forename: F P
authors.initials: FP
authors.lastname: Pralong
authors.forename: B J
authors.initials: BJ
authors.lastname: Blaauboer
authors.forename: M
authors.initials: M
authors.lastname: van den Berg
authors.forename: R H
authors.initials: RH
authors.lastname: Westerink
authors.forename: M B M
authors.initials: MB
authors.lastname: van Duursen
mesh_terms: D000818:Animals; D002460:Cell Line; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D004785:Environmental Pollutants / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D009478:Neuropeptide Y / Q000235:genetics; D056950:Period Circadian Proteins / Q000235:genetics; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D009478:Neuropeptide Y; C539024:Per1 protein, rat; D056950:Period Circadian Proteins; D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D018336:Receptors, Aryl Hydrocarbon; D012701:Serotonin; D007987:Gonadotropin-Releasing Hormone; D019363:Cytochrome P-450 CYP1A1
keywords: AhR; GnV-3 cell line; Hypothalamus; TCDD