Effects of steroid hormones on gene expression of glial markers in the central and peripheral nervous system: Variations induced by aging

The present article summarizes our data regarding: (a) the effect of sex st eroids on the expression of a specific astrocytic marker in glial cell cult ures (GFAP); (b) the effects of aging on two markers of the peripheral myel in (glycoprotein Po and the myelin basic protein, MBP); (c) the possible mo dification of the damaging effects of aging on these two markers by the in vivo administration of progesterone and its derivatives; and, finally, (d) the effect of progesterone derivatives on the gene expression of Po in cult ures of rat Schwannn cells. The data obtained have indicated that progester one and its 5 alpha-reduced metabolites may play an important role in the c ontrol of gene expression of GFAP and Po, respectively, in type 1 astrocyte s and Schwann cells. It has also been found that the gene expression of Po and MBP is dramatically decreased in the myelin of the sciatic nerve of age d male rats and that the aged-linked decrease of the gene expression of Po is partially reversible with steroid treatment. (C) 1998 Elsevier Science I nc.