Promoter Analysis Of Human TNFAIP1 Gene And Its Role In Alzheimer’s Disease

Part 1 Functional characterization of the promoter region ofhuman TNFAIP1 geneTNFAIP1 is an immediate-early response gene of endothelium induced by TNF alpha in the beginning. However, It was demonstrated that TNFAIP1 expression can be induced by other factors as IL6, LPS, EGF, ceramide, Amyloid beta etc ,So the TNFAIP1 expression is regulated severely. However, little is really known concerning the TNFAIP1 expression regulation. To better understand how TNFAIP1 expression is regulated, we cloned the promoter region of TNFAIP1 5’ flank sequence. And we identified the basal promoter region of TNFAIP1 gene by way of constructing a series of absent mutation vector and analysis of luciferase’s activity. We approved that the binding-site of SPl transcription factor can regulate the TNFAIP1’s basal transcription by way of analysis of biological- informatics software and site-directed mutagenesis assays. Moreover, the electrophoretic mobility shift assay and chromatin immunoprecipitation analysis indicated that Spl protein was associated in vivo and in vitro with the TNFAIP1 promoter. Further, Sp1 over-expression enhanced TNFAIP1 promoter activity. These findings suggest that Sp1 is implicated in the control of basal TNFAIP1 gene expression. Therefore, these our experimental findings may become the base of research in transcription-regulated and function of TNFAIP1 gene. Part II The role of TNFAIP1 in Alzheimer’s DiseaseRecently, Link et al. engineered transgenic C. elegans Alzheimer’s disease (AD) model In this transgenic C. elegans model, expression of TNFAIP1 gene was found to be robustly induced, and the in AD brain region with the least pathology had the highest expression of TNFAIP1, suggesting that the TNFAIP1 may plays protective roles during the process of developing AD.The in situ hybridization and immunobiochemistry on mouse embryo suggested that TNFAIP1 was expressed in the whole brain .Because the interactive proteins of TNFAIP1, namely RIN3, ITSN2 ,RhoB and mDia are related to the receptor endocytosis, we detected TNFAIP1 and NMDA receptor and observed that the TNFAIP1 and NMDA receptor subunit NR2B were partially co-localized in Hela. CREB, a transcription factor, is essential in synapse formation of newborn neuron, so that crucial for long-term memory formation. Luciferase report showed that the over-expressed TNFAIP1 could enhance transcription activity of CREB. By treating HEK293 cell lines with high potassium, we observed that the over-expressed TNFAIP1 could increase the phosphorylation of CREB133, thus regulating CREB transcription activity. Therefore, it’s assumed that TNFAIP1 might exert certain protective function during AD pathogenesis.