Fig. 2

ACT001 alleviated microglial activation, decreased neuronal apoptosis and protected the continuity of tight junction proteins in BBB in vivo. a Representative fluorescence images for dual staining of Iba1 and CD68 in peri-contusion region from Sham, TBI and TBI + ACT001 groups at 3 and 7 days post-insult. Scale bar = 250 μm. b Representative fluorescence images of NeuN staining with TUNEL labelling in peri-contusion region from Sham, TBI and TBI + ACT001 groups at 1 and 3 days post-insult. Scale bar = 75 μm. c Representative fluorescence images for dual staining of CD31 and ZO-1, as well as CD31 and Occludin, in peri-contusion region from Sham, TBI and TBI + ACT001 groups at 3 and 7 days post-insult. Scale bar = 200 μm. Cell nuclei were shown in blue (DAPI) in (a–c). d Representative transmission electron microscope images of BBB structure in peri-contusion region from Sham, TBI and TBI + ACT001 groups at 3 and 7 days post-insult. The ultrastructure of BBB in Sham group was normal, the tight junction (orange arrows) of endothelium was compacted and continuous. In mice CCI models, contusion injury disrupted BBB integrity seriously, characterized by translucent cytoplasm, swelling mitochondria and membrane breakdown of endothelium. The tight junction was debonding bead-like (red arrows) at 3 days post-insult in TBI and TBI + ACT001 groups. After ACT001 treatment for 7 days, the BBB integrity (green arrows) in TBI + ACT001 group improved obviously compared with TBI group. Scale bar = 2 μm