Selenoprotein W in overexpressed and underexpressed rat glial cells in culture

Selenium deficiency results in undetectable levels of selenoprotein W (SeW) in muscle but has very little effect upon its content in the brain and thus rat glial cells were studied. Previous work showed that glutathione (GSH) is bound to SeW and this study was undertaken to elucidate its possible antioxidant functions. Full length cDNA of SeW was cloned to inducible LacSwitch expression vector and stably transfected in C6 rat glial cells. After induction, SeW and its mRNA were expressed 22- and 11-fold higher respectively than control. The cDNA coding region of SeW was cloned to the vector in the antisense direction and stably transfected in C6 cells for underexpression of the protein. After induction, SeW expression was reduced to 20% of the control cells. Glutathione peroxidase activity and GSH levels were not significantly different between induced and control cells. There was a greater survival rate of overexpressed than control cells when incubated with 2,2'-Azobis (2-amidinopropane) dihydrochloride (AAPH), suggesting SeW possibly has an antioxidant function.