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

Figure 5

Activation of S1P signaling induces augmented brain damage following M/R injury. S1P or vehicle (veh) was microinjected 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. Brain infarction or neuroinflammation was assessed 22 h after reperfusion. (a) Representative TTC-stained brain slices of veh + M/R, S1P + M/R, and S1P + FTY + M/R. Photographs are coronal brain sections stained with TTC showing infarct area (white) and intact area (red). (b) Percentage of infarct volumes calculated from the TTC-stained brain slices. Infarct volume was measured using Image J software and the percentage of infarction was assessed. (c) Neurological score demonstrating neurological functions. and , compared with the M/R group (veh + M/R) and S1P + M/R group, respectively (Newman-Keuls test). = 6~8 per group. (d) Representative microphotographs of cortex and striatum regions stained with Fluoro-Jade B. Scale bar, 50 µm.

(a)

(b)

(c)

(d)