Increased expression of small heat shock protein αB-crystallin after intracerebral hemorrhage in adult rats.

αB-crystallin (αBC) is involved in diverse cellular activities. Previous studies demonstrated that αBC had anti-apoptotic and proliferation-promoting effects in multiple diseases. Here, we explored the αBC's roles in the pathophysiology of intracerebral hemorrhage (ICH). An ICH rat model was established and assessed by behavioral tests. Using Western blot and immunohistochemistry, significant up-regulation of αBC was found in neurons and astrocytes in brain areas surrounding the hematoma following ICH. Increase of αBC expression was found to be accompanied by the increased expression of proliferating cell nuclear antigen (PCNA), p53, Bax, and active-caspase-3. αBC was co-localized with PCNA in astrocytes or active-caspase-3 in neurons, suggesting its role in astrocyte proliferation and neuronal apoptosis. Our in vitro study, using αBC RNA interference in PC12 cells, indicated that αBC might exert its anti-apoptotic function in neuronal apoptosis. Thus, αBC may play a role in protecting the brain from secondary damage following ICH.