Fig. 4

Presence of active caspase-8 and caspase-3 in CD68-positive cells correlates with age of the ischemic area. Paraffin imbedded brain tissue sections from subjects who suffered from two strokes, referred as recent and old stroke areas, were analyzed by immunohistochemistry for active caspase-8 and caspase-3 expressions using antibodies raised against caspase-8 when cleaved at Asp391 and human caspase-3 when cleaved at Asp175 and compared to healthy control tissue. Cleaved caspase-8 and -3 were detected in tissue from the recent stroke area, but not in healthy control tissue (a). Numbers and levels of CD68-positive cells were markedly increased in recent stroke tissue as compared to control (a), and found to be positive for cleaved caspase-8 and -3 using double immunofluorescence staining analyses (b-c). In contrast, for the older stroke area, lower levels of CD68 were detected as well as very low level/absence for cleaved caspase-8 and -3 (a). Immunofluorescence analysis confirmed the decrease/absence of active caspase-8 and -3 in the CD68-expressing cells within the older stroke area (b-c). Scale bar for IHC images corresponds to 100 μm (a) and for IF images 10 μm (b-c)