Fig. 3

Temporal activation of caspase-8 in Iba1-positive myeloid cells. Frozen tissue sections from mice upon pMCAO (n = 9) were analyzed by immunohistochemistry for expression of active caspase-8 or for expression of the microglia/macrophage marker Iba1. The contralateral side to the ischemic area was used an internal control for each animal. A small increase in body size of Iba1 positive cells was detected in the peri-infarct area at 6 h, with larger increase in cell body and numbers of cells expressing Iba1 detected at 24 and 48 h post occlusion (a). Cleaved caspase-8 was detected at low levels at 6 h, but a significant increase in expression levels was observed at 24 and 48 h in the peri-infarct area, but not at the contralateral side (a). Double immunofluorescent staining revealed that increased active caspase-8 expression was localized in Iba1-positive cells (b). Scale bar represent 100 μm in IHC images (a) and 10 μm in IF images (b)