Effect of pharmaceutical potential endocrine disruptor compounds on protein disulfide isomerase reductase activity using di-eosin-oxidized-glutathione.
BACKGROUND
Protein Disulfide Isomerase (PDI) in the endoplasmic reticulum of all cells catalyzes the rearrangement of disulfide bridges during folding of membrane and secreted proteins. As PDI is also known to bind various molecules including hormones such as estradiol and thyroxin, we considered the hypothesis that adverse effects of endocrine-disrupter compounds (EDC) could be mediated through their interaction with PDI leading to defects in membrane or secreted proteins.


RESULTS
Taking advantage of the recent description of the fluorescence self quenched substrate di-eosin-oxidized-glutathione (DiE-GSSG), we determined kinetically the effects of various potential pharmaceutical EDCs on the in-vitro reductase activity of bovine liver PDI by measuring the fluorescence of the reaction product (E-GSH). Our data show that estrogens (ethynylestradiol and bisphenol-A) as well as indomethacin exert an inhibition whereas medroxyprogesteroneacetate and nortestosterone exert a potentiation of bovine PDI reductase activity.


CONCLUSIONS
The present data indicate that the tested EDCs could not only affect endocrine target cells through nuclear receptors as previously shown, but could also affect these and all other cells by positively or negatively affecting PDI activity. The substrate DiE-GSSG has been demonstrated to be a convenient substrate to measure PDI reductase activity in the presence of various potential EDCs. It will certainly be usefull for the screening of potential effect of all kinds of chemicals on PDI reductase activity.
Klett
Danièle
D
Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, Unit Physiologie de la Reproduction et des Comportements, Nouzilly, France.
Cahoreau
Claire
C
Villeret
Mélanie
M
Combarnous
Yves
Y
D002467:Cell Nucleus / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000378:metabolism* / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D004801:Eosine Yellowish-(YS) / Q000737:chemistry*; D004997:Ethinyl Estradiol / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry / Q000494:pharmacology; D005978:Glutathione / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry; D019704:Protein Disulfide-Isomerases / Q000378:metabolism*; D017510:Protein Folding; D013050:Spectrometry, Fluorescence / Q000379:methods
D004220:Disulfides; D052244:Endocrine Disruptors; D005456:Fluorescent Dyes; D004997:Ethinyl Estradiol; D019704:Protein Disulfide-Isomerases; D005978:Glutathione; D010100:Oxygen; D004801:Eosine Yellowish-(YS)