Microglial Cat H expression was induced at a transcriptional level after LPS injection. ISH staining showed that at 6 h after LPS injection, Cat H mRNA expression was detected in the hippocampus (D), SNr (E), and cerebral cortex (F). At 72 h after LPS injection, the intensity and density of Cat H mRNA positive cells were both increased in the above regions (G-I). In the control, brain Cat H mRNA was absent in the brain (A-C), present only close to the blood vessels (arrows in J). Double staining (Cat H ISH following Iba-1 IHC) showed that cellular localization of Cat H mRNA was perivascular microglia (arrows in L). At 24 h after LPS injection, Cat H mRNA positive signals appeared in microglia in the brain parenchyma, in addition to perivascular microglia (arrows in K, M). The quantification results of Cat H mRNA expression in brain regions analyzed after LPS injection were shown in (N). The detected regions were illustrated in sagittal section of the brain (O). Data were expressed as mean + SEM from three independent experiments. a
P < 0.05 vs control; b
P < 0.01 vs 6 h; c
P < 0.05 vs 72 h; d
P < 0.05 vs 24 h; e
P < 0.01 vs 6 h. Scale bar = 50 μm (A, B, D, E, G, H); 20 μm (C, F, I); 10 μm (J; K, L, M). n = 5.