title: Amphibian transition to the oxidant terrestrial environment affects the expression of glutathione S-transferases isoenzymatic pattern.
abstract: It has been postulated that glutathione S-transferases (GST; EC 2.5.1.18) may play a role in protecting against oxidative stress. In previous studies, we have purified and characterised from Bufo bufo embryos a GST isoenzyme (BbGSTP1-1), which falls at very low level in the adult liver, where a novel isoform (BbGSTP2-2), starts to be highly expressed. During transition to adult life, B. bufo leaves the aquatic environment to live predominantly in the terrestrial environment, characterised by higher oxygen concentration. It has been found that BbGSTP2-2 is more efficient in scavenging from organic hydroperoxides. Therefore, the appearance of BbGSTP2-2 may respond to the necessity of providing the adult toad with a more suitable protection against oxygen toxic by-products. In this work, we performed experiments aimed at verifying if oxidative stress (hyperoxic and H(2)O(2) treatments) could act as a modulator of BbGSTP2-2 expression. Results show that: (a) BbGSTP2 mRNA starts to be expressed in the late embryonic period, while protein appears during metamorphosis; (b) oxidative stress induces anticipation of BbGSTP2 gene expression at both transcriptional and translational levels. These findings seem to indicate that the appearance of BbGSTP2-2 is aimed at endowing the adult toad with more efficient antioxidant defence in the terrestrial atmosphere.
authors.affiliation: Department of Basic and Applied Biology, Faculty of Sciences, University of L'Aquila, Via Vetoio Loc, Coppito 67100 (AQ), Italy. fernanda.amicarelli@univaq.it
authors.forename: Fernanda
authors.initials: F
authors.lastname: Amicarelli
authors.forename: Stefano
authors.initials: S
authors.lastname: Falone
authors.forename: Franca
authors.initials: F
authors.lastname: Cattani
authors.forename: Marina T
authors.initials: MT
authors.lastname: Alamanou
authors.forename: Antonella
authors.initials: A
authors.lastname: Bonfigli
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Zarivi
authors.forename: Michele
authors.initials: M
authors.lastname: Miranda
authors.forename: Anna M
authors.initials: AM
authors.lastname: Ragnelli
authors.forename: Carmine
authors.initials: C
authors.lastname: Di Ilio
mesh_terms: D000818:Animals; D002023:Bufo bufo / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000033:anatomy & histology / Q000502:physiology*; D004777:Environment; D018507:Gene Expression Regulation, Developmental; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D017403:In Situ Hybridization; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D007527:Isoenzymes; D016877:Oxidants; D006861:Hydrogen Peroxide; D005982:Glutathione Transferase; D010100:Oxygen