目的建立体外高表达细胞因子信号转导负调控蛋白3(suppressor of cytokine signaling 3,SOCS3)的细胞模型,为进一步研究SOCS3在炎症因子信号通路中的作用机制提供研究手段。方法通过RT-PCR克隆SOCS3的编码片段,连接至pIRES2-EGFP真核表...目的建立体外高表达细胞因子信号转导负调控蛋白3(suppressor of cytokine signaling 3,SOCS3)的细胞模型,为进一步研究SOCS3在炎症因子信号通路中的作用机制提供研究手段。方法通过RT-PCR克隆SOCS3的编码片段,连接至pIRES2-EGFP真核表达质粒,经测序鉴定后,转染至293T细胞。通过荧光显微镜观测转染效率,RT-PCR和Western印迹法检测SOCS3表达情况,同时检测SOCS3高表达对脂多糖(lipopolysaccharides,LPS)诱导的信号转导和转录激活因子3(signal transducers and activators of transcription 3,STAT3)磷酸化的影响。结果经测序证实,pIRES2-EGFP-SOCS3重建质粒中的SOCS3序列完全正确,转染后细胞中可见明显绿色荧光,且SOCS3在mRNA和蛋白水平表达均显著增加,过表达SOCS3可显著抑制由LPS诱导的STAT3的磷酸化。结论成功构建SOCS3基因重组质粒,转染293T细胞,获得高表达具有功能性SOCS3分子。该细胞模型建立为进一步研究SOCS3的调节机制提供了有利工具。展开更多
目的:研究细胞因子信号转导负调控蛋白3A(suppressor of cytokine signaling 3A,SOCS3A)在多疣壁虎脊髓中的细胞定位及过表达SOCS3A对神经元和星形胶质细胞生物学行为的影响。方法:采用组织免疫荧光方法检测壁虎断尾脊髓中SOCS3A的细胞...目的:研究细胞因子信号转导负调控蛋白3A(suppressor of cytokine signaling 3A,SOCS3A)在多疣壁虎脊髓中的细胞定位及过表达SOCS3A对神经元和星形胶质细胞生物学行为的影响。方法:采用组织免疫荧光方法检测壁虎断尾脊髓中SOCS3A的细胞定位;构建SOCS3A腺病毒,分别在SH-SY5Y神经元细胞株和GSN1壁虎星形胶质细胞株中转染SOCS3A过表达腺病毒,观察对神经元轴突生长及JAK-STAT3的信号通路的影响,对星形胶质细胞增殖及迁移的影响。结果:免疫荧光染色结果表明,SOCS3A与多疣壁虎脊髓中的神经元和星形胶质细胞有共定位。过表达SOCS3A对神经元轴突生长无明显抑制作用,对JAK-STAT3的信号通路无显著影响;过表达SOCS3A可抑制星型胶质细胞的迁移,但对细胞增殖没有明显影响。结论:在多疣壁虎断尾脊髓再生过程中,SOCS3A与神经元和星形胶质细胞的功能相关,不参与JAK-STAT3信号通路发挥调节作用。展开更多
AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined...AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined using the TaqMan miRNA assay.Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction,and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay.Mutation analysis was conducted using the QuikChange Site-Directed Mutagenesis kit.The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region(3'UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay.RESULTS:In hilar cholangiocarcinoma,miR-373 decreased and was closely associated with poor cell differentiation,advanced clinical stage,and shorter survival.The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373.MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373.Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island,and miR-373 negatively regulated MBD2 expression through targeting the 3'UTR.CONCLUSION:MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.展开更多
基金Supported by the National Natural Science Foundation of China(31630002,31470183,21661140002)by the Shanghai Pujiang Program from the Shanghai Municipal Council of Science and Technology~~
文摘【目的】DNA磷硫酰化修饰是DNA骨架上非桥接的氧原子以序列选择性和R-构型被硫取代的一种新型DNA修饰。目前,磷硫酰化修饰在多种细菌、古生菌以及人类致病菌中多有发现,但其分子调控机制尚不清楚。为了全面解析磷硫酰化修饰的调控机制,本文选择荧光假单胞菌Pf0-1为研究对象,开展了其DNA磷硫酰化修饰的调控机制研究。【方法】首先,构建了spfB基因缺失和回补菌株,使用碘能特异性断裂磷硫酰化修饰DNA的方法,研究了该基因缺失对修饰表型的影响。利用cDNA在相邻同方向的基因间隔区进行PCR,确定了磷硫酰化修饰基因簇spf BCDE内的共转录单元。通过荧光定量RT-PCR,分析了spfB基因缺失突变株中磷硫酰化修饰基因的转录量。利用异源表达并纯化得到的重组蛋白SpfB进行了体外功能研究。通过EMSA实验,验证了SpfB蛋白具有与spfB启动子序列结合活性。通过DNase I footprinting实验,精确定位了Spf B蛋白与DNA结合序列。【结果】spf B基因的缺失加剧了磷硫酰化修饰DNA断裂所致电泳条带弥散的表型,spf B基因的回补能够恢复该表型,证明spf B基因负调控磷硫酰化修饰。鉴定了spf基因簇中只含有1个共转录单元,且该共转录单元在?spfB突变株中转录水平明显上升。通过EMSA和DNase I footprint实验,检测了SpfB蛋白与磷硫酰化修饰基因spf BCDE的启动子区域5′-TGTTTGT-3′相结合。【结论】SpfB作为转录调控因子负调控磷硫酰化修饰基因spf BCDE的表达,为解析磷硫酰化修饰的调控机制和全面理解基因组上的部分修饰特征奠定了基础。
文摘目的建立体外高表达细胞因子信号转导负调控蛋白3(suppressor of cytokine signaling 3,SOCS3)的细胞模型,为进一步研究SOCS3在炎症因子信号通路中的作用机制提供研究手段。方法通过RT-PCR克隆SOCS3的编码片段,连接至pIRES2-EGFP真核表达质粒,经测序鉴定后,转染至293T细胞。通过荧光显微镜观测转染效率,RT-PCR和Western印迹法检测SOCS3表达情况,同时检测SOCS3高表达对脂多糖(lipopolysaccharides,LPS)诱导的信号转导和转录激活因子3(signal transducers and activators of transcription 3,STAT3)磷酸化的影响。结果经测序证实,pIRES2-EGFP-SOCS3重建质粒中的SOCS3序列完全正确,转染后细胞中可见明显绿色荧光,且SOCS3在mRNA和蛋白水平表达均显著增加,过表达SOCS3可显著抑制由LPS诱导的STAT3的磷酸化。结论成功构建SOCS3基因重组质粒,转染293T细胞,获得高表达具有功能性SOCS3分子。该细胞模型建立为进一步研究SOCS3的调节机制提供了有利工具。
文摘目的:研究细胞因子信号转导负调控蛋白3A(suppressor of cytokine signaling 3A,SOCS3A)在多疣壁虎脊髓中的细胞定位及过表达SOCS3A对神经元和星形胶质细胞生物学行为的影响。方法:采用组织免疫荧光方法检测壁虎断尾脊髓中SOCS3A的细胞定位;构建SOCS3A腺病毒,分别在SH-SY5Y神经元细胞株和GSN1壁虎星形胶质细胞株中转染SOCS3A过表达腺病毒,观察对神经元轴突生长及JAK-STAT3的信号通路的影响,对星形胶质细胞增殖及迁移的影响。结果:免疫荧光染色结果表明,SOCS3A与多疣壁虎脊髓中的神经元和星形胶质细胞有共定位。过表达SOCS3A对神经元轴突生长无明显抑制作用,对JAK-STAT3的信号通路无显著影响;过表达SOCS3A可抑制星型胶质细胞的迁移,但对细胞增殖没有明显影响。结论:在多疣壁虎断尾脊髓再生过程中,SOCS3A与神经元和星形胶质细胞的功能相关,不参与JAK-STAT3信号通路发挥调节作用。
基金Supported by National Natural Science Foundation of China,No. 81071998Hubei Natural Science Foundation,No.2008CDB159Specialized Research Fund for the Doctoral Program of Higher Education,No. 20070487114
文摘AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined using the TaqMan miRNA assay.Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction,and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay.Mutation analysis was conducted using the QuikChange Site-Directed Mutagenesis kit.The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region(3'UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay.RESULTS:In hilar cholangiocarcinoma,miR-373 decreased and was closely associated with poor cell differentiation,advanced clinical stage,and shorter survival.The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373.MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373.Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island,and miR-373 negatively regulated MBD2 expression through targeting the 3'UTR.CONCLUSION:MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.
