Bax inhibitor-1 is required for resisting the Early Brain Injury induced by subarachnoid hemorrhage through regulating IRE1-JNK pathway

AbstractBackground and PurposeBax inhibitor-1 (BI-1) has been identified as a suppressor of Bax-mediated cell apoptosis by regulation of endoplasmic reticulum stress-induced cell death. However, the role of BI-1 in Early Brain Injury (EBI) after subarachnoid hemorrhage (SAH) remains unclear. In the present study, we aim to explore the neuroprotective functions of BI-1 in EBI after SAH by using models of SAH that induced endovascular perforation in rats.MethodThe neurological score, brain water content and blood-brain barrier (BBB) permeability were evaluated simultaneously as prognostic indicators. Western blot, RT-PCR and TUNEL staining were performed to study the role and mechanisms of BI-1 in EBI after SAH.ResultsWe found that BI-1 knockdown increased histological injury and the percentages of TUNEL-positive neuron in hippocampal, promoted the expressions of endoplasmic reticulum (ER) stress proteins inositol-requiring enzyme 1α (IRE1α) and TNF receptor-associated factor 2 (TRAF2), and increased the ac...