Proteomic analysis of selenium embryotoxicity in cultured postimplantation rat embryos

Developmental toxicity of selenium (Se) is a nutritional, environmental and medicinal concern. Here, we investigated Se embryotoxicity by proteomic analysis of cultured rat embryos.

Rat embryos at day 9.5 or 10.5 of gestation were cultured for 48 or 24 h, respectively, in the presence of sodium selenate (100 or 150 microM) or sodium selenite (20 or 30 microM). Proteins from the embryo proper and yolk sac membrane were analyzed by two-dimensional electrophoresis for quantitative changes from those in control embryos. Proteins with quantitative changes were identified by mass spectrometric analysis.

Growth inhibition and morphological abnormalities of cultured embryos were observed in all the Se treatment groups. By the analysis of the embryo proper, actin-binding proteins were identified as proteins with quantitative changes by selenate: increased phosphorylated-cofilin 1, increased phosphorylated-destrin, decreased drebrin E, and decreased myosin light polypeptide 3. Many proteins showed similar changes between selenate and selenite, including increased ATP-synthase, decreased acidic ribosomal phosphoprotein P0, and decreased pyrroline-5-carboxylate reductase-like. In the yolk sac membrane, antioxidant proteins were identified for protein spots with quantitative changes by selenite: increased peroxiredoxin 1 and increased glutathione S-transferase.

The identified proteins with quantitative changes by selenate or selenite were considered to be candidate proteins involved in Se embryotoxicity: the actin-binding proteins for selenate embryotoxicity, proteins with the similar changes for the common Se embryotoxicity and antioxidant proteins for modification of Se embryotoxicity by redox-related treatments. These proteins may also be used as biomarkers in developmental toxicity studies.