The overall goal of this research is to identify the human genes coordinately regulated by the Antioxidant/Electrophile Responsive Element (ARE/EpRE) and elucidate the mechanism of protein binding and transcriptional activation of the ARE/EpRE. Recently, we identified a human neuroblastoma cell line (IMR-32) that shows dramatic induction of ARE/EpRE reporter constructs and endogenous QR protein by treatment with tert-butylhydroquinone (tBHQ). Others have demonstrated that induction of QR by tBHQ in neuroblastoma cells prior to glutamate treatment significantly decreased glutamate-mediated cytotoxicity suggesting that QR was neuroprotective. Recent studies however have shown that QR is not solely responsible for blocking cytotoxicity since stable overexpression of QR in this same cell line did not confer protection to the cells from dopamine-induced cytotoxicity. We have postulated that a coordinate regulation of multiple genes rather than a single gene product is responsible for the neuroprotection seen with tBHQ pretreatment, and that this coordinate regulation is mediated via the ARE/EpRE. Thus the specific aims of this project are: 1) Identify and characterize differentially expressed genes in IMR-32 human neuroblastoma cells up-regulated by tBHQ. 2) Compare the coordinate regulation of genes leading to neuroprotection by tBHQ, dimethyl fumarate and insulin. 3) Determine whether the transcription factors Nrf1 and Nrf2 are transcriptional activators of the ARE/EpRE in human neuroblastoma cells. Because many types of cell death may involve the formation of oxidants, coordinate regulation of genes identified as containing the ARE/EpRE may lead to a new strategy to combat neurotoxicity.
