Expression of interferon regulatory factor 4 and inflammation in secondary injury of intracerebral haemorrhage

The aim of this study was to investigate the expression of interferon regulatory factor 4 (IRF4) and the inflammatory response in secondary injury of intracerebral haemorrhage (ICH). Twelve SD rats were randomly divided into a sham group and an ICH group, with 6 rats in each group. A rat model of ICH was established by injecting collagenase type IV into the right striatum of rats. The expression of IRF4 was measured by western blot and immunohistochemistry 48 h after ICH. In addition, 15 mm of hemin-induced PC12 cell injury was used to simulate an in vitro ICH model. IRF4 expression was detected by immunofluorescence (IF). Moreover, the inflammatory cytokines (IL-1b and IL-6) were measured by ELISA. The behavioural score of ICH rats was the lowest at 48 h after operation. The expression of IRF4 was significantly higher in the striatal tissue of ICH rats compared with the sham group (p < 0.05). Meanwhile, IF results showed that hemin induced the upregulation of IRF4 expression in rat pheochromocytoma cells PC12. In addition, IL-1b and IL-6 levels were significantly increased in the serum of ICH rats and in the supernatant of hemin-induced PC12 cells (p < 0.01). The inflammation in ICH is related to the increase of IRF4. It provides a theoretical basis for the clinical treatment of ICH.