AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression...AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS： Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION： HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy.展开更多
Background: The late detection of endometrial carcinoma (EC) at an advanced stage often results in a poorpatient prognosis. It is hence important to identify reliable biomarkers to facilitate early detection of EC. Si...Background: The late detection of endometrial carcinoma (EC) at an advanced stage often results in a poorpatient prognosis. It is hence important to identify reliable biomarkers to facilitate early detection of EC. Signaltransducer and activator of transcription (STAT) family members play an important role in several tumors, however,their impact on EC development and progression remains unclear. Methods: Machine learning methods were used toinvestigate the importance of STAT5B in EC. Results: Hence, we explored the UALCAN data mining platform andfound that while STAT1 and STAT2 were upregulated, STAT5A, STAT5B, and STAT6 were downregulated in EC.This high expression of STAT5B and STAT6 predicted favorable clinical outcomes, whereas the increased expressionof STAT1 and STAT2 predicted poor clinical outcomes. Subsequent pathway enrichment analysis revealed that theSTAT family was mainly involved in apoptosis pathway activation, cell cycle disruption, and epithelial–mesenchymaltransition. Drug sensitivity analysis demonstrated that STAT5A/5B expression was negatively correlated with drugresistance in EC. Further, the expression of STAT5B mRNA and protein was correlated with severalclinicopathological characteristics. Tumor Immune Estimation Resource (TIMER) analysis revealed that STAT5Bexpression was positively correlated with the abundance of infiltrating CD8+ T cells and neutrophils while its copynumber variation was associated with the overall immune cell infiltration. The data on the correlations betweenSTAT5B expression and related genes in uterine corpus endometrial carcinoma (UCEC) in cBio Cancer Portalshowed the closest correlation of STAT5B expression with that of KIAA0753 (also known as moonraker and OFIP),followed by COL27A1 in EC. Pathway enrichment analysis further showed that STAT5B-related genes were involvedin the mitogen-activated protein kinase (MAPK) and Ras signaling pathways. Conclusion: Collectively, our findingsprovided new insights into the role of the STAT family in EC. It also highlighted new targets for future research ondiagnostic and prognostic markers and STAT5B as a novel marker for drug sensitivity screening.展开更多
信号转导与转录激活子5(signal transducer and activator of transcription,STAT5)作为一种重要的信号转导与转录激活子,能被多种细胞因子和多肽类激素激活,引起靶基因的转录。参与调控细胞的增殖、分化及凋亡,并对生物体的生长、造血...信号转导与转录激活子5(signal transducer and activator of transcription,STAT5)作为一种重要的信号转导与转录激活子,能被多种细胞因子和多肽类激素激活,引起靶基因的转录。参与调控细胞的增殖、分化及凋亡,并对生物体的生长、造血和免疫应答具有重要意义,其活性的高低与肿瘤的发生和发展关系密切。作者重点阐述了STAT5的结构和生物学功能。展开更多
信号转导及转录活化蛋白5(signal transducer and activator of transcription 5,STAT5)在乳腺发育、免疫应答、细胞代谢、造血及肿瘤的发生发展中发挥重要作用,但对胰岛细胞功能影响研究甚少。本研究旨在探讨STAT5对小鼠胰岛肿瘤MIN6...信号转导及转录活化蛋白5(signal transducer and activator of transcription 5,STAT5)在乳腺发育、免疫应答、细胞代谢、造血及肿瘤的发生发展中发挥重要作用,但对胰岛细胞功能影响研究甚少。本研究旨在探讨STAT5对小鼠胰岛肿瘤MIN6细胞胰岛素分泌的影响及作用机制。电穿孔法转染小干扰RNA(siRNA)敲减STAT5基因表达后,实时定量PCR和蛋白质印迹法显示,与对照干扰RNA转染的细胞比较,Stat5 siRNA转染细胞的mRNA及蛋白质表达水平分别约70%和67%(P<0.01),提示成功构建了Stat5基因沉默模型。酶联免疫吸附法结合蛋白质印迹法显示,与对照组细胞比较,Stat5 siRNA转染细胞在不同浓度葡萄糖刺激下,胰岛素分泌能力提高大约1倍(P<0.05);同时,钙调蛋白依赖的蛋白激酶Ⅱ(calmodulin-dependent protein kinaseⅡ,Ca MKⅡ)的磷酸化水平亦随之加强。加入Ca MKⅡ抑制剂AIPⅡ(auto camtide-2 related inhibitory peptideⅡ)可明显抑制Stat5 siRNA转染导致的细胞胰岛素分泌水平增加(P<0.01)。上述结果表明,沉默Stat5基因后可通过增强Ca MKⅡ的磷酸化促进MIN6细胞胰岛素的分泌。展开更多
旨在建立鹅催乳素(Goose prolactin,gPRL)的高灵敏度的测定方法。本研究设计出基于PRLR-JAKSTAT5信号通路的荧光素酶报告基因系统。首先克隆鹅PRLR基因CDS区序列,合成信号转导和转录激活因子5(Signal transducer and activator of trans...旨在建立鹅催乳素(Goose prolactin,gPRL)的高灵敏度的测定方法。本研究设计出基于PRLR-JAKSTAT5信号通路的荧光素酶报告基因系统。首先克隆鹅PRLR基因CDS区序列,合成信号转导和转录激活因子5(Signal transducer and activator of transcription 5,STAT5)信号应答序列,并分别插入真核表达载体pCMV6-Entry和荧光素酶报告载体pGL3-Enhancer中,构建成为信号接收载体和信号应答载体。然后将两载体同筛选基因载体pEZX-MR03及内参载体pRL-TK共转染到HEK293T细胞中,经嘌呤霉素筛选后获得稳定转染的转基因细胞株。分别用终浓度为0、30、60、90ng·mL^(-1)的PRL刺激转基因细胞,通过qRT-PCR和双荧光素酶检测系统测定在不同PRL浓度下转基因细胞株中荧光素酶(Luciferase,Luc)基因的相对表达量和相对活性的变化。筛选出10株成功整合有全部4个转基因载体的转基因细胞株,经过不同浓度PRL刺激后,筛选出一株细胞,其荧光素酶基因表达量和酶活性均表现出随PRL浓度升高而上调的趋势。结果表明,建立的基于PRLR-JAK-STAT5信号传导系统检测鹅PRL生物活性的新方法是可行的,为准确测定家禽PRL奠定基础。展开更多
The paramyxoviruses are a family of > 30 viruses that variously infect humans, other mammals and fish to cause diverse outcomes, ranging from asymptomatic to lethal disease, with the zoonotic paramyxoviruses Nipah ...The paramyxoviruses are a family of > 30 viruses that variously infect humans, other mammals and fish to cause diverse outcomes, ranging from asymptomatic to lethal disease, with the zoonotic paramyxoviruses Nipah and Hendra showing up to 70% case-fatality rate in humans. The capacity to evade host immunity is central to viral infection, and paramyxoviruses have evolved multiple strategies to overcome the host interferon(IFN)-mediated innate immune response through the activity of their IFN-antagonist proteins. Although paramyxovirus IFN antagonists generally target common factors of the IFN system, including melanoma differentiation associated factor 5, retinoic acid-inducible gene-I, signal transducers and activators of transcription(STAT)1 and STAT2, and IFN regulatory factor 3, the mechanisms of antagonism show remarkable diversity between different genera and even individual members of the same genus; the reasons for this diversity, however, are not currently understood. Here, we review the IFN antagonism strategies of paramyxoviruses, highlighting mechanistic differences observed between individual species and genera. We also discuss potential sources of this diversity, including biological differences in the host and/or tissue specificity of different paramyxoviruses, and potential effects of experimental approaches that have largely relied on in vitrosystems. Importantly, recent studies using recombinant virus systems and animal infection models are beginning to clarify the importance of certain mechanisms of IFN antagonism to in vivo infections, providing important indications not only of their critical importance to virulence, but also of their potential targeting for new therapeutic/vaccine approaches.展开更多
基金Supported by National Natural Science Foundation of ChinaNo. 39670671, No. 30471531
文摘AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS： Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION： HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy.
文摘Background: The late detection of endometrial carcinoma (EC) at an advanced stage often results in a poorpatient prognosis. It is hence important to identify reliable biomarkers to facilitate early detection of EC. Signaltransducer and activator of transcription (STAT) family members play an important role in several tumors, however,their impact on EC development and progression remains unclear. Methods: Machine learning methods were used toinvestigate the importance of STAT5B in EC. Results: Hence, we explored the UALCAN data mining platform andfound that while STAT1 and STAT2 were upregulated, STAT5A, STAT5B, and STAT6 were downregulated in EC.This high expression of STAT5B and STAT6 predicted favorable clinical outcomes, whereas the increased expressionof STAT1 and STAT2 predicted poor clinical outcomes. Subsequent pathway enrichment analysis revealed that theSTAT family was mainly involved in apoptosis pathway activation, cell cycle disruption, and epithelial–mesenchymaltransition. Drug sensitivity analysis demonstrated that STAT5A/5B expression was negatively correlated with drugresistance in EC. Further, the expression of STAT5B mRNA and protein was correlated with severalclinicopathological characteristics. Tumor Immune Estimation Resource (TIMER) analysis revealed that STAT5Bexpression was positively correlated with the abundance of infiltrating CD8+ T cells and neutrophils while its copynumber variation was associated with the overall immune cell infiltration. The data on the correlations betweenSTAT5B expression and related genes in uterine corpus endometrial carcinoma (UCEC) in cBio Cancer Portalshowed the closest correlation of STAT5B expression with that of KIAA0753 (also known as moonraker and OFIP),followed by COL27A1 in EC. Pathway enrichment analysis further showed that STAT5B-related genes were involvedin the mitogen-activated protein kinase (MAPK) and Ras signaling pathways. Conclusion: Collectively, our findingsprovided new insights into the role of the STAT family in EC. It also highlighted new targets for future research ondiagnostic and prognostic markers and STAT5B as a novel marker for drug sensitivity screening.
文摘信号转导与转录激活子5(signal transducer and activator of transcription,STAT5)作为一种重要的信号转导与转录激活子,能被多种细胞因子和多肽类激素激活,引起靶基因的转录。参与调控细胞的增殖、分化及凋亡,并对生物体的生长、造血和免疫应答具有重要意义,其活性的高低与肿瘤的发生和发展关系密切。作者重点阐述了STAT5的结构和生物学功能。
文摘信号转导及转录活化蛋白5(signal transducer and activator of transcription 5,STAT5)在乳腺发育、免疫应答、细胞代谢、造血及肿瘤的发生发展中发挥重要作用,但对胰岛细胞功能影响研究甚少。本研究旨在探讨STAT5对小鼠胰岛肿瘤MIN6细胞胰岛素分泌的影响及作用机制。电穿孔法转染小干扰RNA(siRNA)敲减STAT5基因表达后,实时定量PCR和蛋白质印迹法显示,与对照干扰RNA转染的细胞比较,Stat5 siRNA转染细胞的mRNA及蛋白质表达水平分别约70%和67%(P<0.01),提示成功构建了Stat5基因沉默模型。酶联免疫吸附法结合蛋白质印迹法显示,与对照组细胞比较,Stat5 siRNA转染细胞在不同浓度葡萄糖刺激下,胰岛素分泌能力提高大约1倍(P<0.05);同时,钙调蛋白依赖的蛋白激酶Ⅱ(calmodulin-dependent protein kinaseⅡ,Ca MKⅡ)的磷酸化水平亦随之加强。加入Ca MKⅡ抑制剂AIPⅡ(auto camtide-2 related inhibitory peptideⅡ)可明显抑制Stat5 siRNA转染导致的细胞胰岛素分泌水平增加(P<0.01)。上述结果表明,沉默Stat5基因后可通过增强Ca MKⅡ的磷酸化促进MIN6细胞胰岛素的分泌。
文摘旨在建立鹅催乳素(Goose prolactin,gPRL)的高灵敏度的测定方法。本研究设计出基于PRLR-JAKSTAT5信号通路的荧光素酶报告基因系统。首先克隆鹅PRLR基因CDS区序列,合成信号转导和转录激活因子5(Signal transducer and activator of transcription 5,STAT5)信号应答序列,并分别插入真核表达载体pCMV6-Entry和荧光素酶报告载体pGL3-Enhancer中,构建成为信号接收载体和信号应答载体。然后将两载体同筛选基因载体pEZX-MR03及内参载体pRL-TK共转染到HEK293T细胞中,经嘌呤霉素筛选后获得稳定转染的转基因细胞株。分别用终浓度为0、30、60、90ng·mL^(-1)的PRL刺激转基因细胞,通过qRT-PCR和双荧光素酶检测系统测定在不同PRL浓度下转基因细胞株中荧光素酶(Luciferase,Luc)基因的相对表达量和相对活性的变化。筛选出10株成功整合有全部4个转基因载体的转基因细胞株,经过不同浓度PRL刺激后,筛选出一株细胞,其荧光素酶基因表达量和酶活性均表现出随PRL浓度升高而上调的趋势。结果表明,建立的基于PRLR-JAK-STAT5信号传导系统检测鹅PRL生物活性的新方法是可行的,为准确测定家禽PRL奠定基础。
文摘The paramyxoviruses are a family of > 30 viruses that variously infect humans, other mammals and fish to cause diverse outcomes, ranging from asymptomatic to lethal disease, with the zoonotic paramyxoviruses Nipah and Hendra showing up to 70% case-fatality rate in humans. The capacity to evade host immunity is central to viral infection, and paramyxoviruses have evolved multiple strategies to overcome the host interferon(IFN)-mediated innate immune response through the activity of their IFN-antagonist proteins. Although paramyxovirus IFN antagonists generally target common factors of the IFN system, including melanoma differentiation associated factor 5, retinoic acid-inducible gene-I, signal transducers and activators of transcription(STAT)1 and STAT2, and IFN regulatory factor 3, the mechanisms of antagonism show remarkable diversity between different genera and even individual members of the same genus; the reasons for this diversity, however, are not currently understood. Here, we review the IFN antagonism strategies of paramyxoviruses, highlighting mechanistic differences observed between individual species and genera. We also discuss potential sources of this diversity, including biological differences in the host and/or tissue specificity of different paramyxoviruses, and potential effects of experimental approaches that have largely relied on in vitrosystems. Importantly, recent studies using recombinant virus systems and animal infection models are beginning to clarify the importance of certain mechanisms of IFN antagonism to in vivo infections, providing important indications not only of their critical importance to virulence, but also of their potential targeting for new therapeutic/vaccine approaches.
