PF4 induces inflammatory response through NF-kB signal pathway in rats with intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is a lethal cerebrovascular disorder with a high mortality and morbidity. Although it is a major public health problem, there is no effective treatment for ICH. After ICH, the primary and secondary mechanisms are mentioned when discussing brain injury. The transcription factor, nuclear factor-kappa B (NF-kB), is an important regulator of inflammatory responses. The role of platelet factor 4 (PF4) in ICH is unclear. To study the effect of PF4 on inflammatory response of rats in ICH, a rat model of striatum ICH was established by injecting autologous blood from the autogenous femoral artery into the right striatum of rats. Forty-eight hours after ICH, the expression of PF4, NF-kB (P-P65) and inflammatory changes in rats were determined with WB and ELISA. Heme was used to induce PC12 cell damage, simulate

the ICH model in vitro, and detect PF4, P-P65 and striatal inflammatory changes. Short hairpin RNA (shRNA-PF4) was used to knock-down the expression of PF4 in PC12 cells to detect changes in inflammatory factors. The results showed that 48 hours after surgery, the behavioural score of cerebral haemorrhage was the lowest. The expression of PF4 and P-P65 in the striatum of the ICH group was significantly higher compared with the sham surgery group. The expression of interleukin (IL)-6 and IL-1b in the ICH group was also greatly improved. After inhibiting NF-kB expression, PF4 expression was decreased. In short, ICH enhances the expression of PF4, which induces an inflammatory response in rats with cerebral haemorrhage through the NF-kB signalling pathway. Reducing the expression of PF4 can attenuate the inflammatory response.