Fig. 2. Reactive astrocytes induced by TGFβ1 produce more CSPGs. (A) Monolayers of astrocytes were cultured with (bottom) or without (top) TGFβ1 for 7 days in the absnce of serum. CGNs were plated onto the astrocyte monolayers. After 48 hours, neurons were visualized and axonal length was analyzed. Scale bar: 25 µm. (B) Conditioned medium derived from TGFβ1-treated astrocytes inhibited axonal outgrowth. Conditioned medium was collected from untreated astrocytes (Control) or astrocytes treated with TGFβ1 for 7 days. Dissociated CGNs were then cultured for 48 hours in conditioned medium, alone or with the addition of SB-431542. Relative axonal length was measured and analyzed (^*P<0.01; Student's t-test). (C,D) Increased production of CSPG by TGFβ1-treated astrocytes detected by immunoblot (C) and ELISA (D) using CS-56. Open column, control conditioned medium; filled column, TGFβ1-treated conditioned medium. Data are expressed as the mean ± s.d.