Identification of Protein Targets of Reactive Metabolites of Tienilic Acid in Human Hepatocytes

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemical Research in Toxicology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/tx300103jTienilic acid (TA) is a uricosuric diuretic that was withdrawn from the market only months after its introduction because of reports of serious incidents of drug-induced liver injury including some fatalities. Its hepatotoxicity is considered to be primarily immunoallergic in nature. Like other thiophene compounds, TA undergoes biotransformation to a S-oxide metabolite which then reacts covalently with cellular proteins. To identify protein targets of TA metabolites, we incubated [14C]-TA with human hepatocytes, separated cellular proteins by 2D gel electrophoresis, and analyzed proteins in 36 radioactive spots by tryptic digestion followed by LC-MS/MS. Thirty one spots contained at least one identifiable protein. Sixteen spots contained only one of 14 non-redundant proteins which were thus considered to be targets of TA metabolites. Six of the 14 were also found in other radioactive spots that contained from 1 to 3 additional proteins. Eight of the 14 had not been reported to be targets for any reactive metabolite other than TA. The other 15 spots each contained from 2–4 identifiable proteins, many of which are known targets of other chemically reactive metabolites, but since adducted peptides were not observed, the identity of the adducted protein(s) in these spots is ambiguous. Interestingly, all the radioactive spots corresponded to proteins of low abundance, while many highly abundant proteins in the mixture showed no radioactivity. Furthermore, of approximately 16 previously reported protein targets of TA in rat liver (Methogo, R., Dansette, P. and Klarskov, K. (2007) Int. J. Mass Spectrom., 268, 284–295), only one (fumarylacetoacetase) is among the 14 targets identified in this work. One reason for this difference may be statistical, given that each study identified a small number of targets from among thousands present in hepatocytes. Another may be the species difference (i.e. rat vs. human), and still another may be the method of detection of adducted proteins (i.e. Western blot vs. C-14). Knowledge of human target proteins is very limited. Of more than 350 known protein targets of reactive metabolites, only 42 are known from human and only 21 of these are known to be targets for more than one chemical. Nevertheless, the demonstration that human target proteins can be identified using isolated hepatocytes in vitro should enable the question of species differences to be addressed more fully in the future

Accélération de la production de matériel "mélèze hybride" (2 ème tranche) : rapport d'activité 1992

This report is a summary of the results of experiments conducted in 1992 by the CEMAGREF to improve the production techniques of seeds and plants of hybrid larch (Larix eurolepis Henry). The projects covered four main topics: - floral induction, in orchards, in open-fields and on Japanese larch grown in containers - pollen harvesting including a detailed analysis of the performances of the harvesting machine, and the study on the influence of greenhouse environment on the production of the male strobiles and on pollen quality- artificial pollination - vegetative multiplication. / Ce rapport synthétise les résultats des recherches entreprises en 1992 par le CEMAGREF en vue d'améliorer les techniques de production de graines et de plants de Mélèze hybride (Larix eurolepis Henry). Les travaux concernent 4 grands thèmes : - l'induction florale, en verger de plein-champs et sur plants de mélèze du Japon élevés en conteneurs - la récolte de pollen incluant notamment une analyse détaillée des performances de la machine à récolter et l'étude de l'influence de l'environnement-serre sur la production des stroliles mâles et sur la qualité du pollen - la pollinisation artificielle - la multiplication végétative en vrac

Composantes de la résistance aux rouilles chez les peupliers : utilisation en sélection

25 ref.;Etat et perspectives de la populicultureNational audienceBreeding is a major tool for the control of rust infection in poplar clone stands in Europe. The recent overcoming of resistance by new Melampsora larici-populina rust races raises the question of resistance stability. Based on the assumption that a simple and complete race-specific incompatibility may not be, alone, the most durable form of resistance, this note presents the current knowledge on the different resistance mechanisms under genetic control that could be combined in a selected variety. The physiological basis of general defense mechanisms is also approached. Controlled crosses with Populus deltoides, P. trichocarpa and P. nigra have been used to detect the genetic control of epidemiologic components with high heritability. European poplar breeding programmes benefit from a strong cooperation between scientists in different research field and from the development of new tools for the detailed analysis of the genome which fasten the selection of new clonal varieties. Therefore, special attention should be paid to a real development and diversified use of the selected clones.L'amélioration génétique est le principal outil de protection sanitaire de la peupleraie cultivée en Europe. Le contournement récent des résistances par de nouvelles races de Melampsora larici-populina pose le problème de la stabilité de la résistance. Faisant l'hypothèse que l'incompatibilité race-spécifique seule (ou résistance totale) ne présente pas les garanties de durabilité, nous présentons les différents mécanismes connus de résistance qui sont sous contrôle génétique et qui pourraient être pris en compte dans les schémas de sélection. Nous abordons également l'étude physiologique des mécanismes de défense générale. L'étude du déterminisme génétique des composantes épidémiologiques présentant une forte héritabilité porte sur des croisements contrôlés impliquant Populus deltoides, P. trichocarpa, et P. nigra. Les programmes européens d'amélioration des peupliers bénéficient actuellement d'une collaboration étroite entre différentes disciplines scientifiques et du développement de nouveaux clones. Une attention particulière doit alors être portée à la diffusion et à la diversification des sélections effectivement mises en culture