Possible Involvement of 5α-Reduced Neurosteroids in Adrenergic and Serotonergic Stimulation of GFAP Gene Expression in Rat C6 Glioma Cells

The study investigated the effects of adrenergic and serotonergic stimulation on glial fibrillary acidic protein (GFAP) gene expression in rat C6 glioma cells, serving as a model for glial cell differentiation. It was found that both isoproterenol and serotonin increased GFAP mRNA and protein levels, suggesting their role in glioma cell differentiation. Additionally, progesterone and its 5α-reduced metabolite, dihydroprogesterone, also elevated GFAP mRNA levels. The study demonstrated that the effects of these stimulants were inhibited by finasteride, a 5α-reductase inhibitor, and by antagonists of GABAA and progesterone receptors. This suggested that 5α-reduced neurosteroids might play a role in neuronal regulation of glial cell differentiation.