Exogenous S1P Exposure Potentiates Ischemic Stroke Damage That Is Reduced Possibly by Inhibiting S1P Receptor Signaling

Figure 6

Activation of S1P signaling induces augmented microglial activation and astrogliosis following M/R injury. S1P or vehicle (veh) was injected into the corpus callosum 24 h prior to M/R challenge (60 min occlusion followed by 22 h reperfusion). FTY720 (FTY) was administered into mice 30 min prior to 60 min occlusion. Activation of microglia or astrocytes was assessed 22 h after reperfusion. Representative microphotographs of brain sections immunolabeled against Iba1 (a) or GFAP (b) and their quantitative analysis in groups of sham, veh + M/R, S1P + M/R, and S1P + FTY + M/R. and , compared with M/R group (veh + M/R) (Newman-Keuls test). and , compared with the S1P + M/R group (Newman-Keuls test). per group. Scale bar, 50 µm.

(a)

(b)