Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Meth...Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Methods:The plasmid pCI-neo-X that carries the X gene of hepatitis B virus was transfected into cultured GMCs.HBx expression in the transfected GMCs was assessed by Western-blot.TNF-αprotein and mRNA were assessed by ELISA and semi-quantitative RT-PCR,respectively.Three kinase inhibitors-U0126,an inhibitor of extracellular signal-regulated kinases(ERKs);lactacvstin,an inhibitor of nuclear factor-κB(NF-κB);and SB203580,a selective inhibitor of p38 MAP kinase(p38 MAPK)were used to determine which intracellular signal pathways may underlie the action of HBx on TNF-αexpression in transfected GMCs.Results:A significant increase in HBx expression in pCI-neo-X transfected GMCs was detected at 36 h and 48 h,which was not affected by any of those kinase inhibitors mentioned above.A similar increase in the expression of both TNF-αprotein and mRNA was also observed at 36 h and 48 h,which was significantly decreased in the presence of U0126 or lactacytin,but not SB203580.Conclusions:HBx upregulates TNF-αexpression in cultured GMCs,possibly through ERKs and NF-κB pathway,but not p38 MAPK pathway.展开更多
根据猪链球菌2型(Streptococcus suis type 2,SS2)溶菌酶释放蛋白(muramidase-released protein,MRP)和胞外蛋白因子(extracellular protein factor,EPF)的基因序列,各设计合成一对引物,以猪链球菌2型江苏分离株SS2-1的基因组为模板,扩...根据猪链球菌2型(Streptococcus suis type 2,SS2)溶菌酶释放蛋白(muramidase-released protein,MRP)和胞外蛋白因子(extracellular protein factor,EPF)的基因序列,各设计合成一对引物,以猪链球菌2型江苏分离株SS2-1的基因组为模板,扩增mrp基因1 801~2 513位序列和epf 基因1 783~2 563位序列,分别构建原核表达载体pET32a-mrp 、pET32a-epf,确定诱导表达的两种蛋白都具有免疫原性后,提取阳性克隆质粒各自进行双酶切并纯化,通过PCR串联两片段,将目的片段定向克隆到表达载体pET-32a中,重组质粒转化入大肠杆菌BL21,经IPTG诱导表达分子量约为74kD的融合蛋白.用制备的两种抗血清与纯化融合蛋白进行免疫转印,结果显示融合蛋白分别具有MRP与EPF的中和表位.用融合蛋白MRP-EPF免疫新西兰兔,以最小致死量猪链球菌强毒株SS2-1攻击,兔的存活率达50%(2/4),存活率明显高于单个表达产物.证实串联表达的融合蛋白为重要的保护性抗原.展开更多
探讨信号转导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)与丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)在体内是否存在相互作用,并观察其作用如何影响肿瘤坏死因子-α(tumor necrosis...探讨信号转导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)与丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)在体内是否存在相互作用,并观察其作用如何影响肿瘤坏死因子-α(tumor necrosis factor,TNF-α)的转录活性.采用聚合酶链反应技术,从人Flag-p38和Flag-细胞外信号蛋白调节激酶2(extracellular-signal regulated protein kinase 2,ERK2)中扩增出p38和ERK2基因,将其插入载体pcDNA3-HA中;用Westernblot方法在293T细胞中检测其表达后应用免疫共沉淀技术检测STAT3蛋白与p38/ERK2蛋白之间是否存在相互作用.然后应用报告基因技术检测这种相互作用如何影响TNF-α的转录表达,并在应用RNA干扰技术将STAT3通路抑制后,观察TNF-α启动子转录活性如何变化.酶切和测序结果表明,扩增的p38和ERK2基因序列正确,大小为1080bp,在293T细胞中正确表达大小约40ku的p38和ERK2蛋白.免疫共沉淀实验结果证实,p38和STAT3蛋白以及ERK2和STAT3蛋白在体内相互作用.下游基因TNF-α荧光素酶活性实验显示,p38和STAT3蛋白以及ERK2和STAT3蛋白复合物协同升高TNF-α的活性,应用STAT3的干扰RNA后其活性则明显下降.该研究表明,STAT3和p38/ERK2蛋白在体内存在相互作用,STAT3与p38、STAT3与ERK2均对TNF-α的表达发挥协同效应,在阻断STAT3通路后,STAT3与p38、STAT3与ERK2对TNF-α表达的协同效应将明显降低.展开更多
基金Supported by National Nature Science Foundation of China(GrantNo.30772360)Nature Science Foundation of Health Department of Hubei Province,China(No.JX4B48)Fund of Yangtze University for Doctor(No.2009001)
文摘Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Methods:The plasmid pCI-neo-X that carries the X gene of hepatitis B virus was transfected into cultured GMCs.HBx expression in the transfected GMCs was assessed by Western-blot.TNF-αprotein and mRNA were assessed by ELISA and semi-quantitative RT-PCR,respectively.Three kinase inhibitors-U0126,an inhibitor of extracellular signal-regulated kinases(ERKs);lactacvstin,an inhibitor of nuclear factor-κB(NF-κB);and SB203580,a selective inhibitor of p38 MAP kinase(p38 MAPK)were used to determine which intracellular signal pathways may underlie the action of HBx on TNF-αexpression in transfected GMCs.Results:A significant increase in HBx expression in pCI-neo-X transfected GMCs was detected at 36 h and 48 h,which was not affected by any of those kinase inhibitors mentioned above.A similar increase in the expression of both TNF-αprotein and mRNA was also observed at 36 h and 48 h,which was significantly decreased in the presence of U0126 or lactacytin,but not SB203580.Conclusions:HBx upregulates TNF-αexpression in cultured GMCs,possibly through ERKs and NF-κB pathway,but not p38 MAPK pathway.
文摘根据猪链球菌2型(Streptococcus suis type 2,SS2)溶菌酶释放蛋白(muramidase-released protein,MRP)和胞外蛋白因子(extracellular protein factor,EPF)的基因序列,各设计合成一对引物,以猪链球菌2型江苏分离株SS2-1的基因组为模板,扩增mrp基因1 801~2 513位序列和epf 基因1 783~2 563位序列,分别构建原核表达载体pET32a-mrp 、pET32a-epf,确定诱导表达的两种蛋白都具有免疫原性后,提取阳性克隆质粒各自进行双酶切并纯化,通过PCR串联两片段,将目的片段定向克隆到表达载体pET-32a中,重组质粒转化入大肠杆菌BL21,经IPTG诱导表达分子量约为74kD的融合蛋白.用制备的两种抗血清与纯化融合蛋白进行免疫转印,结果显示融合蛋白分别具有MRP与EPF的中和表位.用融合蛋白MRP-EPF免疫新西兰兔,以最小致死量猪链球菌强毒株SS2-1攻击,兔的存活率达50%(2/4),存活率明显高于单个表达产物.证实串联表达的融合蛋白为重要的保护性抗原.
文摘探讨信号转导和转录激活因子3(signal transducer and activator of transcription 3,STAT3)与丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)在体内是否存在相互作用,并观察其作用如何影响肿瘤坏死因子-α(tumor necrosis factor,TNF-α)的转录活性.采用聚合酶链反应技术,从人Flag-p38和Flag-细胞外信号蛋白调节激酶2(extracellular-signal regulated protein kinase 2,ERK2)中扩增出p38和ERK2基因,将其插入载体pcDNA3-HA中;用Westernblot方法在293T细胞中检测其表达后应用免疫共沉淀技术检测STAT3蛋白与p38/ERK2蛋白之间是否存在相互作用.然后应用报告基因技术检测这种相互作用如何影响TNF-α的转录表达,并在应用RNA干扰技术将STAT3通路抑制后,观察TNF-α启动子转录活性如何变化.酶切和测序结果表明,扩增的p38和ERK2基因序列正确,大小为1080bp,在293T细胞中正确表达大小约40ku的p38和ERK2蛋白.免疫共沉淀实验结果证实,p38和STAT3蛋白以及ERK2和STAT3蛋白在体内相互作用.下游基因TNF-α荧光素酶活性实验显示,p38和STAT3蛋白以及ERK2和STAT3蛋白复合物协同升高TNF-α的活性,应用STAT3的干扰RNA后其活性则明显下降.该研究表明,STAT3和p38/ERK2蛋白在体内存在相互作用,STAT3与p38、STAT3与ERK2均对TNF-α的表达发挥协同效应,在阻断STAT3通路后,STAT3与p38、STAT3与ERK2对TNF-α表达的协同效应将明显降低.
