Institut National de la Recherche Agronomique, Centre National de la Recherche Scientifique, Unit Physiologie de la Reproduction et des Comportements, Nouzilly, France.
PLoS One. 2010 Mar 3;5(3):e9507. doi: 10.1371/journal.pone.0009507.
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.
METHODOLOGY/PRINCIPAL FINDINGS: 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.
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.
所有细胞内质网中的蛋白二硫键异构酶（PDI）在膜结合蛋白和分泌蛋白折叠过程中催化二硫键重排。由于 PDI 已知还可以结合各种分子，包括激素如雌二醇和甲状腺素，我们假设内分泌干扰化合物（EDC）的不良影响可能通过其与 PDI 的相互作用介导，导致膜结合或分泌蛋白的缺陷。
方法/主要发现：利用最近描述的荧光自猝灭底物二-eosin-氧化谷胱甘肽（DiE-GSSG），我们通过测量反应产物（E-GSH）的荧光，测定了各种潜在药物 EDC 对牛肝 PDI 体外还原酶活性的影响。我们的数据表明，雌激素（乙炔雌二醇和双酚 A）以及吲哚美辛表现出抑制作用，而醋酸甲地孕酮和诺特雌醇表现出增强牛 PDI 还原酶活性的作用。
目前的数据表明，测试的 EDC 不仅可以像以前显示的那样通过核受体影响内分泌靶细胞，还可以通过正或负地影响 PDI 活性来影响这些和所有其他细胞。底物 DiE-GSSG 已被证明是一种在存在各种潜在 EDC 的情况下测量 PDI 还原酶活性的方便底物。它肯定会对筛选各种化学物质对 PDI 还原酶活性的潜在影响有用。
