Bex1 attenuates neuronal apoptosis in rat intracerebral hemorrhage model.

Brain expressed x-linked gene 1 (Bex1) which is at high levels in several populations of central nervous system (CNS) neurons, belongs to a family of small proteins of unknown function, playing roles as adaptors or modulators of intracellular signaling pathways. But its distribution and function in CNS remains unclear. Neuronal apoptosis is the major pathogenesis in secondary brain injury of intracerebral hemorrhage (ICH). In this study, the roles of Bex1 were explored in the pathophysiology of ICH. Western blot, immunohistochemistry, and immunofluorescence showed that obvious up-regulation of Bex1 in neurons adjacent to the hematoma after ICH. Furthermore, the increase of Bex1 expression was accompanied by the enhanced expression of Bax and active caspase-3, and decreased expression of B-cell lymphoma 2 (Bcl-2) following ICH. The in vitro study using Bex1 siRNA transfection in hemin-exposed PC12 cells suggested that Bex1 exerted anti-apoptotic function. Therefore, Bex1 may play the neuronal anti-apoptosis role following ICH, implying a novel molecular target for the therapy of ICH.