Identification of a novel gene , OASIS , which encodes for a putative CREB/ATF family transcription factor in the long-term cultured astrocytes and gliotic tissue .
Gliosis is a characteristic response of astrocytes to inflammation and trauma of the central nervous system ( CNS ) .
To study the mechanisms underlying gliosis , we performed differential display screening for genes specifically induced in long-term cultured astrocytes used as an in vitro gliosis model .
We identified and characterized a gene ( named OASIS , for old astrocyte specifically-induced substance ) expressed in long-term cultured mouse astrocytes , or ` old astrocytes ( OA ) ' .
The OASIS gene encoded a putative transcription factor belonging to the cyclic AMP responsive element binding protein/activating transcription factor ( CREB/ATF ) gene family , with homology to box B-binding factor-2 ( BBF-2 ) , a Drosophila transcription factor .
Its expression was developmentally regulated ; OASIS mRNA was primarily expressed in the salivary gland and cartilage in the mouse embryo and it was transiently upregulated in the brain during postnatal two weeks .
The expression became weaker in the adult brain .
We also demonstrated that an expression of the OASIS mRNA was induced in response to the cryo-injury of the mouse cerebral cortex .
The distribution pattern of the OASIS-positive cells in the injured cortex was very similar to that of the glial fibrillary acidic protein ( GFAP ) -positive cells .
These results suggest that OASIS protein may play a role in gliotic events .