Figure 3.

Pharmacological inhibition of S1P₂, but not S1P₁ or S1P₃, eliminates astrocytic inhibition of glutamate uptake by S1P. Primary astrocytes were preincubated (A) with or without 10 μM VPC23019, an antagonist for S1P₁ and S1P₃, for 45 min, (B) 10 μM JTE 013, an S1P₂ antagonist, for 30 min, (C) 200 ng/mL PTX overnight, and (D) 10 μM Y27632 for 30 min at 37°C followed by incubation with or without 20 nM S1P for 1 h. Glutamate uptake assays were performed as described. Data in each panel are representative of two independent experiments (n = 3 or 4). Error bars represent mean ± SD; ns, not significant; **p < 0.005, ***p < 0.001, two-way ANOVA with Sidak’s multiple comparisons test.