title: Tryptophan hydroxylase 2 (TPH2) in a neuronal cell line: modulation by cell differentiation and NRSF/rest activity.
abstract: Serotonin (5-HT) is a neurotransmitter involved in many aspects of the neuronal function. The synthesis of 5-HT is initiated by the hydroxylation of tryptophan, catalyzed by tryptophan hydroxylase (TPH). Two isoforms of TPH (TPH1 and TPH2) have been identified, with TPH2 almost exclusively expressed in the brain. Following TPH2 discovery, it was reported that polymorphisms of both gene and non-coding regions are associated with a spectrum of psychiatric disorders. Thus, insights into the mechanisms that specifically regulate TPH2 expression and its modulation by exogenous stimuli may represent a new therapeutic approach to modify serotonergic neurotransmission. To this aim, a CNS-originated cell line expressing TPH2 endogenously represents a valid model system. In this study, we report that TPH2 transcript and protein are modulated by neuronal differentiation in the cell line A1 mes-c-myc (A1). Moreover, we show luciferase activity driven by the human TPH2 promoter region and demonstrate that upon mutation of the NRSF/REST responsive element, the promoter activity strongly increases with cell differentiation. Our data suggest that A1 cells could represent a model system, allowing an insight into the mechanisms of regulation of TPH2 and to identify novel therapeutic targets in the development of drugs for the management of psychiatric disorders.
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Second University of Naples, Caserta, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Gentile
authors.forename: Yukino
authors.initials: Y
authors.lastname: Nawa
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Lunardi
authors.forename: Tullio
authors.initials: T
authors.lastname: Florio
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsui
authors.forename: Luca
authors.initials: L
authors.lastname: Colucci-D'Amato
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D002461:Cell Line, Transformed; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000166:cytology* / Q000201:enzymology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D014365:Tryptophan Hydroxylase / Q000096:biosynthesis* / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics; D000099229:RE1-Silencing Transcription Factor
chemical_list: D012097:Repressor Proteins; D014365:Tryptophan Hydroxylase; D000099229:RE1-Silencing Transcription Factor; C487801:Tph1 protein, mouse; C487802:Tph2 protein, mouse