Figure 3

mRNA expression of myelin genes P0, and KROX-20 of rat Schwann cells (rSCs) and myelin morphology after stimulation with interleukin 17 (IL-17). (A) mRNA expression of myelin genes P0 and KROX-20 is normalized to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and to control cultures. A significant decrease in KROX-20 mRNA expression to 51% (**P ≤0.01) was seen on stimulation with 5 and 50 ng/mL IL-17. P0 mRNA showed a significant down-regulation to 84% expression with 5 ng/mL IL-17 (*P ≤0.05) and a non-significant down-regulation to 92% expression with 50 ng/mL IL-17. For P0 and KROX-20 and both concentrations applied; an analysis of variance between the three independent experiments revealed no significant difference. (B) Ultrastructure of the myelin layer of dorsal root ganglia (DRG) co-cultures after IL-17 stimulation (5 ng/mL IL-17, top row) and control cultures (bottom row). Cultures were stimulated from day 6 after preparation and fixed after 28 days in vitro. The left images depict a longitudinal section and the right images a traverse section referring to the axonal fiber. Myelin showed no morphological alterations after IL-17 stimulation. AU, arbitrary unit; Ax, axon; My, myelin layer.