title: Dietary keto-acid feed-back on pituitary activity in gilthead sea bream: effects of oral doses of AKG. A proteomic approach.
abstract: The influence of a daily oral dose of alpha-ketoglutarate (AKG, 0.1 g/kg body weight), an intermediate metabolite in the Krebs cycle and a dietary additive, on the pituitary proteome of gilthead sea bream was determined by two-dimensional electrophoresis (2-DE). A high-resolution map of the sea bream pituitary proteome was generated. Proteins with a modified expression between Controls and AKG treated fish were further analysed by MALDI-TOF/TOF-MS and liquid chromatography combined with a nanoelectrospray (LC-MS/MS). The main changes in the proteome induced by AKG treatment were grouped. Metabolic proteins up-regulated with AKG supplementation included fructose-bis-phosphate aldolase, glyceraldehyde-phosphate dehydrogenase and malate dehydrogenase, all related to glucose metabolism (p<0.000). Protein folding related up-regulation with AKG supplementation included two isoforms of heat shock proteins as well as cyclophylin and chaperonin (p<0.000). An unexpected form of apolipoprotein-A-1 with lower molecular weight (15-16 kDa) was evidenced as being highly abundant in the pituitary proteome of Controls, yet it was down-regulated by AKG treatment. Finally, proteins found to be associated with regeneration of neural function namely cofilin and Vat-protein were up-regulated after AKG supplementation. The only hormone to be modified by AKG treatment was somatolactin, which was significantly down-regulated cf. Controls. In summary, these results provide evidence of a potential endocrine/metabolic regulatory loop activated by AKG supplementation.
authors.affiliation: Xarxa de Referència i Recerca en Aqüicultura de la Generalitat de Catalunya, Dept. Fisiologia (Biologia), Univ Barcelona, Diagonal 645, E-08028 Barcelona, Spain. tibarz@ub.edu
authors.forename: Antoni
authors.initials: A
authors.lastname: Ibarz
authors.forename: Rita
authors.initials: R
authors.lastname: Costa
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Harrison
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Power
mesh_terms: D000818:Animals; D004032:Diet; D005246:Feedback; D007656:Ketoglutaric Acids / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects* / Q000502:physiology*; D017510:Protein Folding / Q000187:drug effects; D020543:Proteome / Q000187:drug effects*; D021541:Sea Bream / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007656:Ketoglutaric Acids; D020543:Proteome