title: Chronic ethanol treatment alters purine nucleotide hydrolysis and nucleotidase gene expression pattern in zebrafish brain.
abstract: Ethanol is a widely consumed drug that acts on the central nervous system (CNS), modifying several signal transduction pathways activated by hormones and neurotransmitters. The zebrafish is an experimental model for the study of human diseases and the use of this species in biochemical and behavioral studies on alcoholism and alcohol-dependence has increased recently. However, there are no data concerning the effects of chronic ethanol exposure on the purinergic system, where extracellular nucleotides act as signaling molecules. Purinergic signaling is controlled by a group of enzymes named ectonucleotidases, which include NTPDases and ecto-5'-nucleotidase already characterized in zebrafish brain. The aim of this study was to evaluate nucleotide hydrolysis by NTPDases and ecto-5'-nucleotidase after long-term ethanol exposure. Additionally, the gene expression patterns of NTPDases1-3 and 5'-nucleotidase were determined. Animals were exposed to 0.5% ethanol for 7, 14, and 28 days. There were no significant changes in ATP and GTP hydrolysis after all treatments. However, a decrease in ADP (46% and 34%) and GDP (48% and 36%) hydrolysis was verified after 7 and 14 days, respectively. After 7 and 14 days of ethanol exposure, a significant decrease in AMP hydrolysis (48% and 36%) was also observed, whereas GMP hydrolysis was inhibited only after 7 days (46%). NTPDase2_mv and NTPDase3 mRNA transcript levels decreased after 7 and 14 days, respectively. In contrast, ethanol increased NTPDase1, NTPDase2_mq, and NTPDase3 transcript levels after 28 days of exposure. NTPDase2_mg and 5'-nucleotidase gene expression was not altered. Therefore, the ectonucleotidase pathway may be a target of chronic ethanol toxicity and the regulation of purinergic system could play a key role in the neurochemical mechanisms underlying the effects of ethanol on the CNS.
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil. edurico@portoweb.com.br
authors.forename: Eduardo Pacheco
authors.initials: EP
authors.lastname: Rico
authors.forename: Denis Broock
authors.initials: DB
authors.lastname: Rosemberg
authors.forename: Andrei da Silveira
authors.initials: Ada S
authors.lastname: Langoni
authors.forename: André Arigony
authors.initials: AA
authors.lastname: Souto
authors.forename: Renato Dutra
authors.initials: RD
authors.lastname: Dias
authors.forename: Maurício Reis
authors.initials: MR
authors.lastname: Bogo
authors.forename: Carla Denise
authors.initials: CD
authors.lastname: Bonan
authors.forename: Diogo Onofre
authors.initials: DO
authors.lastname: Souza
mesh_terms: D015720:5'-Nucleotidase / Q000235:genetics / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D000431:Ethanol / Q000633:toxicity*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006868:Hydrolysis; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D029961:Zebrafish Proteins; D006153:Guanosine Diphosphate; D000431:Ethanol; D000244:Adenosine Diphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D015720:5'-Nucleotidase; D000251:Adenosine Triphosphatases; C027201:ectoATPase