Abstract
Previous studies have shown that transcription factors, API and NFkB exert important roles in the process by which selenium regulates spermatogenesis. Glutathione, an intracellular thiol, acts as a source of reducing power and aids in maintenance of the cellular redox status. The activities of selenium are closely related to the availability of glutathione. Presently, mouse testicular cells were cultured in the presence of BSO, a known glutathione depletor, to generate oxidative stress. Selenium (Se) was added as sodium selenite to these cells at concentrations of 0.5 microM and 1.5 microM. It was observed that at 1.5 microM, Se acted as a pro-oxidant and significantly decreased the redox ratio. RT PCR analysis revealed that cjun, cfos expression increased in testicular cells cultured with Se compared to control. However, the major outcome was that the combined effect of Se supplementation and GSH depletion resulted in reduced expression of cjun and cfos while p65 expression increased. This suggests that selenium affects both these transcription factors differently. Our study indicates that though low levels of oxidative stress generated by moderate doses of selenium augments the expression of cjun and cfos, a robust increase in the ROS generation caused by the dual effect high levels of selenium and glutathione depletion leads to decrease in the expression of these genes. The present work substantiates our in vivo experiments and indicates the detrimental effect of excess selenium supplementation on male fertility.
Highlights
Oxidative stress due to excessive generation of reactive oxygen species (ROS) has been associated with defective sperm function and infertility (Sharma and Agarwal, 1996; Agarwal and Saleh, 2002)
Oxidized Glutathione (GSSG): There was a significant decrease in the levels of oxidized glutathione (GSSG), when testicular cells were exposed to 10 nM Buthionine sulfoximine (BSO) compared to the control cells
No change was observed in cells exposed to varying concentrations of selenium compared to the control cells or when incubated simultaneously with selenium and BSO (Table III)
Summary
Oxidative stress due to excessive generation of reactive oxygen species (ROS) has been associated with defective sperm function and infertility (Sharma and Agarwal, 1996; Agarwal and Saleh, 2002). Selenium (Se), a essential trace element, plays an important role in the process of sperm development in mammals. It forms an important constituent of the enzyme glutathione peroxidase (GSH Px) which is actively involved in the removal of both organic and inorganic peroxides (Rotruck et al, 1973). It is known that selenium plays a crucial role in the function of many important enzymes, such as glutathione peroxidase and thioredoxin reductase which are closely related to the antioxidant defense mechanism or cell growth regulation (Powis et al, 1997; Ganther, 1999). It has been demonstrated that reaction of selenite with reduced form of glutathione (GSH) during metabolism leads to the formation of reactive oxygen species, ROS (Shen et al, 2000)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.