Apoptosis plays an essential role in ischemic stroke pathogenesis. Research on the process of
neuronal apoptosis in models of ischemic brain injury seems promising. The role of growth arrest
and DNA-damage-inducible protein 45 beta (Gadd45b) in brain ischemia has not been fully examined
to date. This study aims to investigate the function of Gadd45b in ischemia-induced
apoptosis. Adult male Sprague-Dawley rats were subjected to brain ischemia by middle cerebral
artery occlusion (MCAO). RNA interference (RNAi) system, which is mediated by a lentiviral
vector (LV), was stereotaxically injected into the ipsilateral lateral ventricle to knockdown
Gadd45b expression. Neurologic scores and infarct volumes were assessed 24 h after reperfusion.
Apoptosis-related molecules were studied using immunohistochemistry and Western blot analysis.
We found that Gadd45b-RNAi significantly increased infarct volumes and worsened the
outcome of transient focal cerebral ischemia. Gadd45b-RNAi also significantly increased neuronal
apoptosis as indicated by increased levels of Bax and active caspase-3, and decreased levels of
Bcl-2. These results indicate that Gadd45b is a beneficial mediator of neuronal apoptosis