CCAAT-enhancer binding proteinα is expressed in activated microglial cells after brain injury

Microglial cells play important roles in brain injury and repair and are implicated in diseases such as Alzheimer's disease, Creutzfeldt–Jacob disease, multiple sclerosis, the Aids Dementia Complex and stroke. Despite their importance in neuropathology, the underlying molecular basis for the activation of microglia after brain injury is not understood. We show, using RT-PCR, in situ hybridisation, immunocytochemistry, and electrophoretic mobility shift assay, that the CCAAT-enhancer binding proteinα (C/EBPα), a sequence specific DNA-binding protein, is induced in microglial cells, but not astrocytes or neurons, after hypoxic–ischemic brain injury. These results suggest that C/EBPα might regulate gene expression and consequentially have a role in the activation and/or proliferation of microglia following brain injury.