C286 suppresses CSPGs in reactive astrocytes via neuronal release of decorin. A, Illustration of the cell culture treatments: LPS-activated astrocytes were treated with vehicle, decorin (20 μg/ml), or C286 or with conditioned medium from neurons previously treated with vehicle (V-CM) or C286 (C286-CM) in the presence or absence of decorin Nab, which was added to C286-treated neurons and astrocyte cultures that were treated with C286 + decorin NAb-CM. B, Expression of CD44 and CSPGs in the astrocyte cultures. Scale bar, 20 μm. C, D, Decorin and C286-CM treatment significantly suppresses CSPGs and CD44, an effect that is abolished by the addition of decorin NAb to the cultures. Data represent mean of fluorescence intensity for CSPGs in arbitrary units (a.u.) ± SEM taken from 10 fields per culture condition from three independent experiments. ***p ≤ 0.001, one-way ANOVA followed by Fisher's post hoc test. E, F, LPS-activated astrocytes treated with vehicle or C286 and immunoassayed for GFAP (E) and decorin (F) showed no significant difference in decorin expression between the two treatments. Data represent mean of fluorescence intensity for decorin in arbitrary units (a.u.) ± SEM taken from 10 fields per culture condition from three independent experiments. n.s., Not significant, Student's t test.