The Apoptotic Molecular Changes of Cellular Injury in Mouse Testis Induced by Endocrine Disrupting Chemicals

ABSTRACT

BACKGROUND: Spermatogenesis is regulated by various cellular reactions, and especially cell proliferation and apoptosis. METHODS: We investigated the morphological changes and the apoptotic molecular changes in mouse testis induced by the endocrine disrupting chemicals. ICR mice were treated with bisphenol A (BPA), 2-bromopropane (2-BP) and diethylstilbesterol (DES). Histological examination and immunohistochemical staining, TUNNEL staining and RNAse protection assay were conducted. RESULTS: Testes treated with BPA showed normal spermatogenesis and the proliferation activity, and the density of the cells was similar with those in the control. 2-BP and DES groups, which showed a decrease of germ cells near the basal layer and degenerative changes. The proliferative activity identified by PCNA staining was significantly decreased in the 2-BP and DES groups (p<0.05). The apoptosis was significantly increased in the 2-BP group however, a significant decrease was noted in the BPA group (p<0.05). Among apoptosis-related molecules, the expression of Fas, Fas ligand, TRAIL, TNFp55 and caspase 1, 3, 6 and 8 were changed according to the change of the degree of apoptosis in all groups. CONCLUSIONS: Endocrine disrupting chemicals induced cellular injury in mouse testis through the changes of proliferative activity and apoptosis which was regulated by a number of apoptosis-related molecules. This probably results in the abnormality of spermatogenesis in mouse testis.