Bessong, Pascal O.Hahn, Young ShinJennelle, LucasMagoro, Tshifhiwa2019-10-162019-10-162019-09-20Magoro, Tshifhiwa (2019) Characterization of cholesterol 25-hydroxylase expression in human macrophages, University of Venda, South Africa.<http://hdl.handle.net/11602/1474>.http://hdl.handle.net/11602/1474PhD (Microbiology)Department of MicrobiologyBackground Conversion of Cholesterol to 25-HydroxyCholesterol (25HC) by Cholesterol 25-hydroxylase (CH25H) has been shown to exert broad antiviral properties. Given its antiviral activities, CH25H is part of an increasingly appreciated connection between type I interferon (IFN-I) and lipid metabolism. Moreover, the details of this connection appear to differ in mouse and human cells. Nevertheless, the molecular basis for the induction of CH25H in humans is not known. Objective Elucidation of signaling and transcriptional events for induction of CH25H expression is critical to design therapeutic antiviral agents. Materials and methods: Wildtype THP-1 monocytic cell-line or THP-1 MyD88 Knockout cell-line were treated with PMA for 72 hours for differentiation into macrophages. Differentiated macrophages or Microglial cells were stimulated with either TLR-agonists, pro-inflammatory cytokine, or interferons, and CH25H mRNAs expression levels were measured by qPCR. Results In this study, we show that CH25H is induced by Zika virus infection or TLR stimulation. Interestingly, CH25H is induced by pro-inflammatory cytokines including 1L- 1, TNF-, and IL-6, and this induction depends on STAT-1 transcription factor. Additionally, we have observed that ATF3 weakly binds to the CH25H promoter, suggesting co-operation with STAT-1. However, ZIKV induced CH25H was independent of type I interferon. Conclusion This study has demonstrated for the first time that pro-inflammatory cytokines such as 1L-1, TNF-, and IL-6 induce CH25H expression. Moreover, this provides further understanding to the connection between innate immunity and sterol metabolism and encourages the exploration of cytokines in antiviral immunity.1 online resource (xviii, 169 leaves)enUniversity of VendaCholestrol 25-hydroxylaseUCTD25-hydroxylasePro-inflammatory cytokinesSTAT-1ATF3TFLR Stimulation572.5795Cholesterol hydroxylaseOxidoreductasesMacrophagesThesisMagoro T. Characterization of cholesterol 25-hydroxylase expression in human macrophages. []. , 2019 [cited yyyy month dd]. Available from: http://hdl.handle.net/11602/1474Magoro, T. (2019). <i>Characterization of cholesterol 25-hydroxylase expression in human macrophages</i>. (). . Retrieved from http://hdl.handle.net/11602/1474Magoro, Tshifhiwa. <i>"Characterization of cholesterol 25-hydroxylase expression in human macrophages."</i> ., , 2019. http://hdl.handle.net/11602/1474TY - Thesis AU - Magoro, Tshifhiwa AB - Background Conversion of Cholesterol to 25-HydroxyCholesterol (25HC) by Cholesterol 25-hydroxylase (CH25H) has been shown to exert broad antiviral properties. Given its antiviral activities, CH25H is part of an increasingly appreciated connection between type I interferon (IFN-I) and lipid metabolism. Moreover, the details of this connection appear to differ in mouse and human cells. Nevertheless, the molecular basis for the induction of CH25H in humans is not known. Objective Elucidation of signaling and transcriptional events for induction of CH25H expression is critical to design therapeutic antiviral agents. Materials and methods: Wildtype THP-1 monocytic cell-line or THP-1 MyD88 Knockout cell-line were treated with PMA for 72 hours for differentiation into macrophages. Differentiated macrophages or Microglial cells were stimulated with either TLR-agonists, pro-inflammatory cytokine, or interferons, and CH25H mRNAs expression levels were measured by qPCR. Results In this study, we show that CH25H is induced by Zika virus infection or TLR stimulation. Interestingly, CH25H is induced by pro-inflammatory cytokines including 1L- 1, TNF-, and IL-6, and this induction depends on STAT-1 transcription factor. Additionally, we have observed that ATF3 weakly binds to the CH25H promoter, suggesting co-operation with STAT-1. However, ZIKV induced CH25H was independent of type I interferon. Conclusion This study has demonstrated for the first time that pro-inflammatory cytokines such as 1L-1, TNF-, and IL-6 induce CH25H expression. Moreover, this provides further understanding to the connection between innate immunity and sterol metabolism and encourages the exploration of cytokines in antiviral immunity. DA - 2019-09-20 DB - ResearchSpace DP - Univen KW - Cholestrol 25-hydroxylase KW - 25-hydroxylase KW - Pro-inflammatory cytokines KW - STAT-1 KW - ATF3 KW - TFLR Stimulation LK - https://univendspace.univen.ac.za PY - 2019 T1 - Characterization of cholesterol 25-hydroxylase expression in human macrophages TI - Characterization of cholesterol 25-hydroxylase expression in human macrophages UR - http://hdl.handle.net/11602/1474 ER -