European Journal of Biomedical and Pharmaceutical Sciences

SALINOMYCIN INDUCES APOPTOSIS IN GERM CELLS OF MOUSE TESTIS

Olajumoke Omolara Ojo and Srikanta Kumar Rath*

ABSTRACT

Apoptosis is a strictly regulated process involving sequential activation of specific signal transduction pathway, disturbance of mitochondrial membrane function causing the release of intermembrane proteins into the cytosol and subsequent stepwise degradation of the cell. Adverse effect of Salinomycin on male reproductive organs and male infertility had been reported, however, the underlying mechanisms are still unclear. This study therefore investigates the possibility of Salinomycin-induced apoptosis through the interplay of bcl-2 and bax proteins in mouse testis. Eight groups of mice received 1, 3 and 5 mg/kg Salinomycin per day for a 28 days period. Four groups were sacrificed directly after the treatment while four groups were sacrificed 28 days after withdrawal of the treatment. Primarily, the role of apoptosis following Salinomycin exposure was evaluated using microarray profiling to assess effect of Salinomycin on essential genes in reproductive pathways. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling method (TUNEL) shows an increased number of positive staining germ cells in the testicles of Salinomycin-treated mice across the dose groups (< 0.05). Down regulation of Caspase 3 activity was also observed. Western blot analysis further reveals down regulation of bcl-2 protein with simultaneous up-regulation of bax apoptosis protein in testicles samples. A number of the regulated genes involved in reproductive pathways such as Adam 2, Spam, Tnp1, Tnp2, CYP11A1 and STRAD 6 are grossly affected. In general, microarray study reveals distinct expression profiles and patterns of regulated genes, dependent on the specific dose of Salinomycin. Conclusively, this study confirmed induction of apoptosis and further established dose dependent- adverse effects of Salinomycin on the male reproductive system.

Keywords: Salinomycin; Apoptosis; Testicular Germ cell; Gene expression.