Apoptosis Effects on Primary Rats Sertoli Cells by Microcystin-LR

摘要

Microcystin-LR (MC-LR) is the most frequently studied cyclic heptapeptide produced by different genera of cyanobacteria in diverse water systems. The adverse effects of MC-LR on reproductive system have been studied in vitro, however, the mechanisms have not been fully elucidated. The aim of this study was to investigate the apoptosis effects induced by MC-LR on primary rat Sertoli cells, and to explore its potential apoptotic induction mechanism. Sertoli cells isolated and purified from SD rat were treated with MC-LR for 24h.The cytotoxicity was assessed with MTT bioassay; apoptotic cells were identified microscopically by chromatin condensation with Hoechst33258; p53 and other apoptosis-related proteins such as Bax and Bcl-2, were determined by Western blot analysis, and the related mRNA expressions were determined by reverse transcriptase-polymerase chain reaction(RT-PCR). The caspase activity was measured by cleavage of the caspase substrate(Ac-DEVD-pNA for caspase-3).The results of MTT bioassay showed that MC-LR inhibited the growth of Sertoli cells in a concentration-dependent way. The result of Hoechst33258 staining indicated that MC-LR induces Sertoli cells apoptosis. Increase of p53 and bax proteins , decrease of bcl-2 protein were observed.Caspase-3 activities increased. These results suggested that MC-LR exposure can change the expression of apoptosis-related genes, and that MC-LR can induce apoptosis in Sertoli cells of rats and may have relations with some apoptosis-related diseases.