Figure 1.

The expression of IRF4 is elevated during middle cerebral artery occlusion and oxygen glucose deprivation (OGD). (a) Immunoblotting of IRF4 in brains subjected to ischaemia/reperfusion (I/R) for the indicated time points. GAPDH served as a loading control in each lane. For each time point, three independent experiments were performed in triplicate. *P<0.0001 versus sham, post hoc Tukey's test with Bonferroni correction. (b and c) IRF4 is upregulated in neurons following stroke onset. The mice were subjected to I/R for 24 h, and their brains were co-stained with IRF4 (red) and either (b) NEUN (green) or (c) MAP2 (green). The nuclei were stained using 4′6-diamino-2-phenylindole (DAPI). The insets show higher magnification views. Scale bar: 20 μm. Right panel: the number of IRF4-positive neurons was quantified. Four to five independent experiments were performed. *P=0.0063 (b) and 0.0240 (c) versus contralateral controls, unpaired Student's t-test. (d) Representative immunofluorescence images of IRF4 (red), NEUN (green) and DAPI (blue) in the hippocampus, cortex and striatum regions from the ipsilateral and contralateral sides, following 24-h I/R. Merged images are shown. Scale bar: 20 μm. Right panels: the number of IRF4-positive neurons was quantified. Four independent experiments were performed. *P=0.0185 (cortex) and 0.0003 (striatum) versus contralateral controls unpaired Student's t-test. (e) The primary cortical neurons were treated with OGD/reperfusion for the indicated time points. The cells were then co-stained with IRF4 (red), MAP2 (green) and nuclei (DAPI). Scale bar: 50 μm. Right panel shows IRF4 intensity in neurons. Three independent experiments were performed. *P=0.0004 (6 h), <0.0001 (12 h) and <0.0001 (24 h) versus control, post hoc Tukey's test with Bonferroni correction. The values are the means±S.E