Figure 6

Delayed exacerbation of neuronal apoptosis in Toll-like receptor 2 deficient mice. (A) Photomicrographs of cleaved caspase-3 immunoreactivity in wild-type (WT) and Toll-like receptor (TLR) 2 −/− mice 3,7 and 14 days after transient middle cerebral artery occlusion (MCAO). (B) Quantification of labeled cells showed a higher number of apoptotic cells in WT compared with TLR2−/− mice 3 days after injury, while 7 days after injury the number of cleaved caspase-3-positive cells was significantly higher in the TLR2−/− group compared with the WT group of mice. The number of cleaved caspase-3-positive cells was higher in TLR2−/− mice 14 days after transient MCAO, but not significantly because of high variation within the group. (C) Double immunofluorescence analysis reveals a high proportion of cleaved caspase-3 (green) positive cells correlating with the neuronal marker NeuN (red, co-localization marked with white arrows). (D) No co-localization was observed for GFAP (red) and cleaved caspase-3 (green). (E) Only a few cleaved caspase-3-positive cells (green) showed co-localization with Iba1 (red, co-localization marked with white arrow heads), while the vast majority were not co-localizing. Data (B) are expressed as mean ± SEM (n = 4, *P <0.05, **P <0.001). Scale bars: A, C, D, E, 25 μm.