Up-regulation of Che-1 relates to neuronal apoptosis after traumatic brain injury in adult rats.

Che-1, a recently identified apoptosis related protein, affects the fate of various cell types when under stress. One attractive biological function of Che-1 is promoting the transcription of p53 after DNA damage; besides, it can also regulate cell cycle via interacting with retinoblastoma protein. Although previous evidence has showed its anti-apoptotic role in cancer cells, some studies point out that Che-1 might play an opposite role in central nervous system (CNS). However, the function of Che-1 in CNS is still with limited acquaintance. To investigate whether Che-1 is involved in CNS lesion, we performed a traumatic brain injury model in adult rats. Up-regulation of Che-1 was observed in the peritrauma brain cortex by performing western blotting and immunohistochemistry. Terminal deoxynucleotidyl transferase deoxy-UTP nick-end labeling and 4',6-diamidino-2-phenylindole staining suggested that Che-1 was involved in neuronal apoptosis after brain injury. We also investigated co-localization of Che-1 and active-caspase-3 in the ipsilateral brain cortex. In addition, the expression patterns of p53, Bax and PCNA were parallel with that of Che-1. Besides this, neurotrophin receptor-interacting MAGE homolog was found to be associated with Che-1 after brain trauma. Based on our data, we suggested that Che-1 might play an important role in neuronal apoptosis following TBI; and might provide a basis for the further study on its role in regulating the expression of p53 and cell cycle re-entry in traumatic brain injury.