Figure 10.

Increases in LCN2 expression in mixed glial cultures and astrocyte-enriched cultures after treatment with MMP-9. A, SH-SY5Y neurons differentiated by treatment with 10 μm RA for 5 d were exposed to 100 μm MPP⁺ and the levels of MMP-9 zymogen in the culture medium were measured by gelatin zymography 24 h after the MPP⁺ treatment. The levels of MMP-9 were increased significantly in the SH-SY5Y neuronal cultures treated with MPP⁺ compared with normal controls. *p < 0.05, significantly different from untreated controls (t test; n = 4). B, C, Mixed glia and astrocyte-enriched cultures were treated with MMP-9 (100 and 500 ng/ml) and the levels of LCN2 protein in the culture medium were measured by ELISA 24 h after the MMP-9 treatment. The levels of LCN2 were increased significantly in both glial cultures (B) and astrocyte-enriched cultures (C) treated with MMP-9 compared with normal controls. *p < 0.05, significantly different from untreated controls (one-way ANOVA; n = 3). Lipopolysaccharide (LPS; 100 ng/ml) and interferon gamma (IFN-γ; 50 units/ml) were used as positive controls for LCN2 induction. **p < 0.01 and *p < 0.05, significantly different from the untreated control (one-way ANOVA; n = 3).