title: Butyrate, a gut-derived environmental signal, regulates tyrosine hydroxylase gene expression via a novel promoter element.
abstract: Butyrate is a diet-derived, gut fermentation product with an array of effects on cultured mammalian cells including inhibition of proliferation, induction of differentiation and regulation of gene expression. We showed that physiological concentrations of butyrate can regulate transcription of tyrosine hydroxylase (TH) and preproenkephalin (ppEnk) gene in PC12 cells. In promoter deletion studies, electrophoretic mobility shift assays and by site-directed mutagenesis, we identified a novel butyrate response element (BRE) in the 5' upstream region of the rat TH gene, homologous to the previously mapped motif in the ppEnk promoter. No such enhancers were found in DBH or PNMT promoters, and both catecholamine system-related gene promoters were unaffected by butyrate. The BRE motif interacts with nuclear proteins in a sequence-specific manner, shows binding potentiation in butyrate-differentiated PC12 cells and bound protein(s) are competed away with TH-CRE oligonucleotides or by the addition of CREB-specific antibodies, suggesting involvement of CREB or CREB-related transcription factors. Moreover, single point mutation in the distal BRE abolished binding of transcription factors and reduced the response to butyrate in transient transfection studies. The canonical CRE motif of the TH promoter was also found necessary for transcriptional activation of the TH gene by butyrate. Our data identified a novel functional element in the promoter of both the TH and ppEnk genes mediating transcriptional responses to butyrate. Dietary butyrate may have an extended role in the control of catecholamine and endogenous opioid production at the level of TH and ppEnk gene transcription neuronal plasticity, cardiovascular functions, stress adaptation and behavior.
authors.affiliation: Division of Newborn Medicine, Department of Pediatrics, New York Medical College, Valhalla, NY 10595, USA.
authors.forename: Pranav
authors.initials: P
authors.lastname: Patel
authors.forename: Bistra B
authors.initials: BB
authors.lastname: Nankova
authors.forename: Edmund F
authors.initials: EF
authors.lastname: LaGamma
mesh_terms: D000313:Adrenal Medulla / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D000818:Animals; D002087:Butyrates / Q000378:metabolism* / Q000494:pharmacology; D002395:Catecholamines / Q000096:biosynthesis*; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000235:genetics; D004745:Enkephalins / Q000096:biosynthesis / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics*; D016297:Mutagenesis, Site-Directed; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D016716:PC12 Cells; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics; D051381:Rats; D020218:Response Elements / Q000187:drug effects / Q000235:genetics; D015533:Transcriptional Activation / Q000187:drug effects / Q000235:genetics; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*
chemical_list: D002087:Butyrates; D002395:Catecholamines; D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D004745:Enkephalins; D011498:Protein Precursors; C033660:preproenkephalin; D014446:Tyrosine 3-Monooxygenase