Functional Role of Transcription Factor Sp1 in Brain Neuronal Injury( I )

Brain injury insults cause neuronal death mainly through apoptosis. Numerous genes modulated in this moment involve in neuronal survival or death. Therefore, to uncover the gene regulation under brain injury is important for looking for the therapeutic strategy of brain injury including the trauma and stroke. Our previous studies have reported that Sp1 can be induced through a cap-independent pathway to protect the neuron from apoptosis under the ischemic condition in cell level. In order to target Sp1 or its regulated genes in the treatment of brain injury, several points about the functional role of Sp1 in brain neuronal injury still need to be further addressed. First, how does Sp1 use the internal ribosome entry site (IRES)-system to speed translation efficiency to protect neuron cells? To this point, we will use the various signal inhibitors to block the signal pathway triggered in brain injury to determine which signal pathway is important for the Sp1 accumulation. In addition, we will synthesise the 5’-UTR of Sp1 by using in vitro transcription assay to search a probe for the IRES-transacted factor (ITAF) complex, and then use LC/MS to identify those proteins involved in the cap-independent translational pathway to express Sp1. Second, which target genes repertoire is regulated by Sp1 under brain injury. We will use cDNA array and chromatin immunoprecipitation/next generation sequence (ChIP-NGS) assay to screen the Sp1-regulated genes under brain injury condition, and further address the functional role of those genes in neuron protection. Third, what are the functional roles of an important chaperone, sigma receptor regulated by Sp1 under brain injury condition. We will overexpression or knockdown of the sigma receptor in primary cultured neuron cells under oxygen-glucose deprivation (OGD) condition. Finally, we will generate the transgenic or knockout animal models of Sp1 and sigma receptor to support the conclusion from cell level studies, and use these animal model to test the therapeutic strategies. Through this study, we will clarify the role and mechanism of Sp1 and sigma receptor in the brain injury animal models, the expected results will benefit the therapeutic study of brain injury in the future.