Expression and distribution of p-JNK and JNK proteins in the P7 rat brain after HI as detected by Western blot analysis and fluorescence immunolabeling.

<p>Samples were obtained from the cortex. Equal levels of protein samples (100 μg) were loaded, and GAPDH served as a loading control. The values are expressed as the relative optical density and represented as the mean±SD (n = 5). Total JNK protein was not obviously changed at different time points compared with sham controls (A). However, p-JNK protein levels transiently decreased at 0.5 h, increased at 6 and 24 h, peaked at 48 h, and lasted until 72 h (A). The JNK and p-JNK expression levels in the HI groups and sham controls were quantified. The data were obtained by densitometry and normalized to GAPDH. *p<0.05, **p<0.01 compared with the sham control (B). (HI, hypoxia-ischemia). The cell type specificity of p-JNK with double fluorescent immunolabeling (n = 5). p-JNK, the neuron-specific marker NeuN and the astrocyte-specific marker GFAP were visualized using a p-JNK antibody followed by a FITC-conjugated secondary antibody (green) and NeuN or GFAP followed by a TRITC-conjugated secondary antibody (red). The nucleus was stained by DAPI (blue). p-JNK (C, D) immunoreactivity colocalized to neurons (yellow) and astrocytes (yellow) in the ischemic cortex. Scale bar, 50 μm.