目的采用生物信息学技术研究7-脱氢胆固醇还原酶(DHCR7)在膀胱癌中的表达及其与临床预后的关系等。方法采用TCGA、GEO数据库分析膀胱癌与正常膀胱组织中DHCR7基因的表达,利用Human Protein Atlas数据库验证DHCR7蛋白在膀胱癌组织中的表...目的采用生物信息学技术研究7-脱氢胆固醇还原酶(DHCR7)在膀胱癌中的表达及其与临床预后的关系等。方法采用TCGA、GEO数据库分析膀胱癌与正常膀胱组织中DHCR7基因的表达,利用Human Protein Atlas数据库验证DHCR7蛋白在膀胱癌组织中的表达,通过Kaplan Meier法分析DHCR7基因表达水平与膀胱癌患者预后及生存情况之间的关系;应用GeneMANIA数据库构建蛋白质互作网络(PPI),并通过GEPIA2分析互作基因在膀胱癌中的相关性;依据DHCR7基因mRNA相对表达水平,应用GSEA 4.1.0软件对TCGA数据进行分层基因富集分析。结果膀胱癌组织中DHCR7基因mRNA相对表达水平明显高于癌旁组织及正常膀胱组织,差异有统计学意义(P<0.05);不同肿瘤分期、分级、分子分型膀胱癌组织中DHCR7基因mRNA相对表达水平比较,差异有统计学意义(P<0.05);与DHCR7低表达组相比,DHCR7高表达组的总生存期、肿瘤特异性生存期、无进展生存期更低,差异有统计学意义(P<0.05);PPI及基因富集分析显示DHCR7基因功能主要与胆固醇稳态、MTORC1通路等有关。结论DHCR7基因在膀胱癌中高表达,与临床不良预后密切相关,DHCR7基因可能通过多种机制参与肿瘤发展过程,有望成为膀胱癌干预治疗、预后评估新的靶点。展开更多
A series of N5-substituted 8-deaza-5,6,7,8-tetrahydromethotrexate derivatives were synthesized and evaluated as inhibitors of dihydrofolate reductase（DHFR）.The results indicated that modification of the pteridine ri...A series of N5-substituted 8-deaza-5,6,7,8-tetrahydromethotrexate derivatives were synthesized and evaluated as inhibitors of dihydrofolate reductase（DHFR）.The results indicated that modification of the pteridine ring of methotrexate（MTX） rendered poor activity against human DHFR.展开更多
7-Dehydrocholesterol(7-DHC),a key pharmaceutical intermediate in the production of vitamin D3,has a wide range of applications.To explore fermentative synthesis of 7-DHC,a 7-DHC-producing Saccharomyces cerevisiae stra...7-Dehydrocholesterol(7-DHC),a key pharmaceutical intermediate in the production of vitamin D3,has a wide range of applications.To explore fermentative synthesis of 7-DHC,a 7-DHC-producing Saccharomyces cerevisiae strain was constructed by blocking the competitive pathway,eliminating rate-limiting steps,altering global reg-ulation,and pathway compartmentalization.After blocking the competitive pathway by disrupting ERG5 and ERG6 and introducing DHCR24 from Gallus gallus,S.cerevisiae produced 139.72 mg/L(17.04 mg/g dry cell weight,hereafter abbreviated as DCW)7-DHC.Subsequent alteration of global regulation by deleting ROX1 and overexpressing UPC2-1 increased 7-DHC production to 217.68 mg/L(37.56 mg/g DCW).To remove the accu-mulated squalene,the post-squalene pathway was strengthened by co-overexpression of PGAL1-driven ERG11 and PGAL10-driven ERG1,which improved 7-DHC titer and yield to 281.73 mg/L and 46.78 mg/g DCW,respectively,and reduced squalene content by 90.12%.We surmised that the sterol precursors in the plasma membrane and peroxisomes may not be accessible to the pathway enzymes,thus we re-localized DHCR24p and Erg2p-GGGGS-Erg3p to the plasma membrane and peroxisomes,boosting 7-DHC production to 357.53 mg/L(63.12 mg/g DCW).Iron supplementation further increased 7-DHC production to 370.68 mg/L in shake flasks and 1.56 g/L in fed-batch fermentation.This study demonstrates the power of global regulation and subcellular relocalization of key enzymes to improve 7-DHC synthesis in yeast.展开更多
Cytochrome P450 reductase(POR)is an essential electron transfer protein located on the endoplasmic reticulum of most cell types,and has long been appreciated for its role in cytochrome P450-mediated drug metabolism.Ad...Cytochrome P450 reductase(POR)is an essential electron transfer protein located on the endoplasmic reticulum of most cell types,and has long been appreciated for its role in cytochrome P450-mediated drug metabolism.Additional roles and electron acceptors for POR have been described,but it is largely with the recent availability of POR-null tissues that these supplemental roles for POR have been able to be explored.These studies have confirmed POR as the principal redox partner for the microsomal P450s responsible for drug and xenobiotic metabolism as well as cholesterol and bile acid synthesis,and for heme oxygenase,which catalyzes the initial step in the breakdown of heme.Surprisingly,these studies have revealed that squalene monooxygenase,an enzyme essential to cholesterol synthesis,has a second unknown redox partner in addition to POR,and that 7-dehydrocholesterol reductase,previously proposed to require POR as an electron donor,functions fully independently of POR.These studies have also helped define the role of cytochrome b5 in P450 catalysis,and raise the question as to the extent to which POR contributes to b5-dependent redox pathways.展开更多
Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to im...Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.展开更多
文摘目的采用生物信息学技术研究7-脱氢胆固醇还原酶(DHCR7)在膀胱癌中的表达及其与临床预后的关系等。方法采用TCGA、GEO数据库分析膀胱癌与正常膀胱组织中DHCR7基因的表达,利用Human Protein Atlas数据库验证DHCR7蛋白在膀胱癌组织中的表达,通过Kaplan Meier法分析DHCR7基因表达水平与膀胱癌患者预后及生存情况之间的关系;应用GeneMANIA数据库构建蛋白质互作网络(PPI),并通过GEPIA2分析互作基因在膀胱癌中的相关性;依据DHCR7基因mRNA相对表达水平,应用GSEA 4.1.0软件对TCGA数据进行分层基因富集分析。结果膀胱癌组织中DHCR7基因mRNA相对表达水平明显高于癌旁组织及正常膀胱组织,差异有统计学意义(P<0.05);不同肿瘤分期、分级、分子分型膀胱癌组织中DHCR7基因mRNA相对表达水平比较,差异有统计学意义(P<0.05);与DHCR7低表达组相比,DHCR7高表达组的总生存期、肿瘤特异性生存期、无进展生存期更低,差异有统计学意义(P<0.05);PPI及基因富集分析显示DHCR7基因功能主要与胆固醇稳态、MTORC1通路等有关。结论DHCR7基因在膀胱癌中高表达,与临床不良预后密切相关,DHCR7基因可能通过多种机制参与肿瘤发展过程,有望成为膀胱癌干预治疗、预后评估新的靶点。
基金National Natural Science Foundation of China(Grant No.20972011)
文摘A series of N5-substituted 8-deaza-5,6,7,8-tetrahydromethotrexate derivatives were synthesized and evaluated as inhibitors of dihydrofolate reductase（DHFR）.The results indicated that modification of the pteridine ring of methotrexate（MTX） rendered poor activity against human DHFR.
基金supported by the National Key Research and Devel-opment Program of China(2021YFC2103700)National Natural Science Foundation of China(32171412)the Fundamental Research Funds for the Central Universities(226-2022-00055).
文摘7-Dehydrocholesterol(7-DHC),a key pharmaceutical intermediate in the production of vitamin D3,has a wide range of applications.To explore fermentative synthesis of 7-DHC,a 7-DHC-producing Saccharomyces cerevisiae strain was constructed by blocking the competitive pathway,eliminating rate-limiting steps,altering global reg-ulation,and pathway compartmentalization.After blocking the competitive pathway by disrupting ERG5 and ERG6 and introducing DHCR24 from Gallus gallus,S.cerevisiae produced 139.72 mg/L(17.04 mg/g dry cell weight,hereafter abbreviated as DCW)7-DHC.Subsequent alteration of global regulation by deleting ROX1 and overexpressing UPC2-1 increased 7-DHC production to 217.68 mg/L(37.56 mg/g DCW).To remove the accu-mulated squalene,the post-squalene pathway was strengthened by co-overexpression of PGAL1-driven ERG11 and PGAL10-driven ERG1,which improved 7-DHC titer and yield to 281.73 mg/L and 46.78 mg/g DCW,respectively,and reduced squalene content by 90.12%.We surmised that the sterol precursors in the plasma membrane and peroxisomes may not be accessible to the pathway enzymes,thus we re-localized DHCR24p and Erg2p-GGGGS-Erg3p to the plasma membrane and peroxisomes,boosting 7-DHC production to 357.53 mg/L(63.12 mg/g DCW).Iron supplementation further increased 7-DHC production to 370.68 mg/L in shake flasks and 1.56 g/L in fed-batch fermentation.This study demonstrates the power of global regulation and subcellular relocalization of key enzymes to improve 7-DHC synthesis in yeast.
文摘Cytochrome P450 reductase(POR)is an essential electron transfer protein located on the endoplasmic reticulum of most cell types,and has long been appreciated for its role in cytochrome P450-mediated drug metabolism.Additional roles and electron acceptors for POR have been described,but it is largely with the recent availability of POR-null tissues that these supplemental roles for POR have been able to be explored.These studies have confirmed POR as the principal redox partner for the microsomal P450s responsible for drug and xenobiotic metabolism as well as cholesterol and bile acid synthesis,and for heme oxygenase,which catalyzes the initial step in the breakdown of heme.Surprisingly,these studies have revealed that squalene monooxygenase,an enzyme essential to cholesterol synthesis,has a second unknown redox partner in addition to POR,and that 7-dehydrocholesterol reductase,previously proposed to require POR as an electron donor,functions fully independently of POR.These studies have also helped define the role of cytochrome b5 in P450 catalysis,and raise the question as to the extent to which POR contributes to b5-dependent redox pathways.
基金supported by the National Natural Science Foundation of China(81730061,81802008)the Guangdong Basic and Applied Basic Research Foundation(2021A1515011272).
文摘Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.
