Differential expression of peroxiredoxin 6, annexin A5 and ubiquitin carboxyl-terminal hydrolase isozyme L1 in testis of rat fetuses after maternal exposure to di-n-butyl phthalate.

OBJECTIVE

To isolate and identify differentially expressed proteins in testis of rat fetuses after maternal exposure to di-n-butyl phthalate (DBP).

METHODS

Pregnant rats were daily treated by gavage with 1 ml/kg corn oil or 750 mg/kg DBP from GD14 to GD18. We used the technique of proteomic analysis to compare the testis protein patterns obtained by two-dimensional gel electrophoresis from fetal rats of gestation day 19.

RESULTS

We found significant differences in protein spot intensities compared to control. Subsequently several of these variant protein spots were identified by mass spectrometry. Peroxiredoxin 6 (Prdx6), annexin A5 (AnxA5) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UchL1) were three of them, the differential expression of which were confirmed by western blotting. Further, immunohistochemical analyses of fetal rat testes sections were made to determine the cellular distribution of these proteins, consequently strong Prdx6 and AnxA5 stainings were found primarily in Leydig cells, while a weak UchL1 staining was found primarily in spermatogonium.

CONCLUSIONS

The present study had found several differentially regulated proteins and demonstrated the differential expression of Prdx6, AnxA5 and UchL1 in fetal rat testis after maternal exposure to DBP, when compared with controls. Combining the cellular location of these proteins and their function in other tissues, the results of this study indicated that oxidative injury and abnormal apoptotic regulation might participate the formation of testicular dysgenesis in fetuses of dams exposed to DBP.