Regulation of Macrophage Migration Inhibitory Factor Gene Expression in an Infection Model

• Main Authors: Wu, CHAN-CHAIO, 吳真嶠
• Other Authors: CHANG, WEN-TENG
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/08502395970587174937

碩士 === 中華醫事科技大學 === 生物科技系暨生物醫學研究所 === 105 === Abstract Immune response to the invasion of foreign objects will activate endothelial cells, macrophages and other white blood cells to release a large number of biomarkers, such as macrophage migration inhibitory factor (MIF) and inflammation-related cytokines, such as TNF-α, IL-1 IL-6, IL-8 and so on, which directly or indirectly cause organ failure. Among them, few literatures reported the promoter studies of the pro-inflammatory cytokine MIF gene in the bacterial infection models, as well as the functions and importance of transcription factors in regulation of the MIF promoter activity. Therefore, in this study, we investigated the role of transcription factors in the regulation of MIF gene promoter and immune functions in an infection model. We constructed several promoter-reporter constructs with different length of MIF promoter fragments to study the promoter activities and used sited-directed mutagenesis to mutate the putative transcription factor sites to elucidate the role of these sites in regulating MIF gene expression. We found that MIF-157 fragment contains a basal promoter activity. Treatment of LPS induced MIF promoter activities but dexamethasone reduced these effects in all fragments except for MIF+44. Mutation of two Sp1 sites, CRE and HIF-1 on MIF-157 fragment decreased the MIF promoter activity. Mutation of HIF-1 on MIF-157 fragment also decreased the effects of LPS and dexamethasone. Mutation of putative GR site on MIF-508 fragment also decreased the promoter activity. However, mutation of putative F-ACT1 site increased the promoter activity. According to these results, we found that several transcription factors may play important roles in regulating basal promoter activity of MIF as well as the effects of LPS and dexamethasone on MIF gene expression.