TIPE2 attenuates neuroinflammation and brain injury through Bcl-2/Bax/cleaved caspase-3 apoptotic pathways after intracerebral hemorrhage in mice.

BACKGROUND

Intracerebral hemorrhage (ICH) is a serious disease with high mortality and morbidity, and effective treatment is limited. A large amount of evidence suggests that the inflammatory response contributes to secondary brain damage following ICH. TIPE2 is an essential negative regulator of both innate and adaptive immunity, and depletion of TIPE2 causes inflammatory disease. However, the possible role of TIPE2 following ICH has not been reported.

METHODS

In this study, we investigated TIPE2 levels and inflammation in microglia treated with erythrocyte lysate in vitro. In addition, we analyzed the role of Bcl-2/Bax/cleaved caspase-3 apoptotic pathways in ICH mice. Furthermore, we observed proinflammatory cytokine production, BBB disruption, cerebral water content and neurological damage in ICH mice.

RESULTS

We found that TIPE2 levels were significantly decreased in erythrocyte lysate-treated microglia compared to control microglia.Upregulation of TIPE2 decreased microglia activation and cytokine production and accelerated brain damage in ICH mice. Furthermore, upregulation of TIPE2 decreased the higher ratio of Blc-2/Bax and increased cleaved caspase-3 levels in ICH mice. In addition, upregulation of TIPE2 attenuated proinflammatory cytokine production, BBB disruption, and severe brain inflammation after ICH.

CONCLUSION

These results demonstrated that TIPE2 was negatively correlated with the pathogenesis of ICH, which prevented brain injury and attenuated deleterious inflammatory responses following ICH. TIPE2 might serve as a novel target for ICH therapy.