There are many kinds of Chinese patent medicine used to fight against influenza efficiently in clinical practice. However, little experimental data confirmed the anti-influenza the activities since non-suitable animal...There are many kinds of Chinese patent medicine used to fight against influenza efficiently in clinical practice. However, little experimental data confirmed the anti-influenza the activities since non-suitable animal model and in vitro antiviral experiments. This paradox can be explained by host factors are important in the patho- genesis and outcome of influenza infection. Accordingly, we set up a mouse model by using restraint stress plus vi- ral infection, which is more conducive to simulate the clinical features of susceptible population and evaluate the activities of Chinese herbal medicine. Our results demonstrated that stress-induced corticosterone （CORT） , a stres- sor sensor, increased the morbidity and the mortality of virus infected mice loaded with restraint stress. CORT also increased expression of Mfn2, and accordingly decreased mitochondrial antiviral signaling （MAVS） aggregates in the host cells. Mfn2 overexpression increased NP and decreased IFN-β and IFITM3 protein expressions in influenza virus infected A549 cells. These findings suggested that the mechanism of restraint stress increased the susceptibili- ty due to CORT induces activation of Mfn2 mediated MAVS pathway.展开更多
AIM:To develop a sensitive assay for screening compounds against hepatitis C virus (HCV).METHODS:The proteolytic cleavage of NS3/4A on enhanced yellow fluorescent protein (eYFP)-mitochondrial antiviral signaling prote...AIM:To develop a sensitive assay for screening compounds against hepatitis C virus (HCV).METHODS:The proteolytic cleavage of NS3/4A on enhanced yellow fluorescent protein (eYFP)-mitochondrial antiviral signaling protein (MAVS) was examined by reporter enzyme secreted placental alkaline phosphatase (SEAP),which enabled us to perform ongoing monitoring of anti-HCV drugs through repeated chemiluminescence.Subcellular localization of eYFP-MAVS was assessed by fluorescence microscopy.Cellular localization and protein levels were examined by Western blotting.RESULTS:HCV NS3/4A protease cleaved eYFP-MAVSfrom mitochondria to block the activation of interferon (IFN)-β promoter,thus resulting in downregulation of SEAP activity.The decrease in SEAP activity was proportional to the dose of active NS3/4A protease.Also this reporter assay was used to detect anti-HCV activity of IFN-α and cyclosporine A.CONCLUSION:Our data show that this reporter system is a sensitive and quantitative reporter of anti-HCV inhibitors.This system will constitute a new tool to allow the efficient screening of HCV inhibitors.展开更多
目的探讨乙型肝炎(乙肝)表面抗原(Hepatitis B surface antigen,HBsAg)阳性母亲乙肝病毒(Hepatitis B virus,HBV)DNA载量和婴儿出生时线粒体抗病毒信号蛋白(Mitochondrial antiviral signaling protein,MAVS)信号通路对婴儿接种乙肝疫苗...目的探讨乙型肝炎(乙肝)表面抗原(Hepatitis B surface antigen,HBsAg)阳性母亲乙肝病毒(Hepatitis B virus,HBV)DNA载量和婴儿出生时线粒体抗病毒信号蛋白(Mitochondrial antiviral signaling protein,MAVS)信号通路对婴儿接种乙肝疫苗(Hepatitis B vaccine,HepB)无/弱应答的影响。方法选择2019年11月至2022年6月太原市某医院分娩的HBsAg阳性母亲及其婴儿,检测母亲HBV DNA载量、婴儿出生时脐血免疫细胞比例和MAVS信号通路蛋白表达百分比、婴儿乙肝免疫球蛋白和HepB全程接种后1-2月血清乙肝表面抗体(Hepatitis B surface antibody,HBsAb)。采用多因素Logistic回归模型分析HBV DNA和MAVS信号通路对婴儿接种HepB无/弱应答的影响。结果婴儿HepB全程接种后无/弱应答率为14.38%(22/153)。多因素Logistic回归分析显示,母亲HBV DNA载量高、脐血MAVS、pIRF3和pNF-κB蛋白表达百分比低、脐血浆细胞比例低的婴儿HepB无/弱应答率高[OR(95%CI):3.94(1.11-14.00)、1.44(1.15-1.73)、4.17(1.16-14.96)、1.94(1.38-2.51)、3.97(1.14-13.79)]。结论HBsAg阳性母亲HBV DNA载量和婴儿出生时MAVS信号通路显著影响婴儿接种HepB的免疫应答;相关检测有助于识别HepB无/弱应答高危人群。展开更多
Retinoic acid-inducible gene I(RIG-I)is an important pattern recognition receptor that detects viral RNA and triggers the production of type-I interferons through the downstream adaptor MAVS(also called IPS-1,CARDIF,o...Retinoic acid-inducible gene I(RIG-I)is an important pattern recognition receptor that detects viral RNA and triggers the production of type-I interferons through the downstream adaptor MAVS(also called IPS-1,CARDIF,or VISA).A series of structural studies have elaborated some of the mechanisms of dsRNA recognition and activation of RIG-I.Recent studies have proposed that K63-linked ubiquitination of,or unanchored K63-linked polyubiquitin binding to RIG-I positively regulates MAVS-mediated antiviral signaling.Conversely phos-phorylation of RIG-I appears to play an inhibitory role in controlling RIG-I antiviral signal transduction.Here we performed a combined structural and biochemical study to further define the regulatory features of RIG-I signaling.ATP and dsRNA binding triggered dimeriza-tion of RIG-I with conformational rearrangements of the tandem CARD domains.Full length RIG-I appeared to form a complex with dsRNA in a 2:2 molar ratio.Com-pared with the previously reported crystal structures of RIG-I in inactive state,our electron microscopic struc-ture of full length RIG-I in complex with blunt-ended dsRNA,for the first time,revealed an exposed active conformation of the CARD domains.Moreover,we found that purified recombinant RIG-I proteins could bind to the CARD domain of MAVS independently of dsRNA,while S8E and T170E phosphorylation-mimick-ing mutants of RIG-I were defective in binding E3 ligase TRIM25,unanchored K63-linked polyubiquitin,and MAVS regardless of dsRNA.These findings suggested that phosphorylation of RIG inhibited downstream signaling by impairing RIG-I binding with polyubiquitin and its interaction with MAVS.展开更多
Acute myocardial infarction(MI),one of the most common cardiovascular emergencies,is a leading cause of morbidity and mortality.Ample evidence has revealed an essential role for inflammasome activation and autophagy i...Acute myocardial infarction(MI),one of the most common cardiovascular emergencies,is a leading cause of morbidity and mortality.Ample evidence has revealed an essential role for inflammasome activation and autophagy in the pathogenesis of acute MI.Tax1-binding protein 1(TAX1BP1),an adaptor molecule involved in termination of proinflammatory signaling,serves as an important selective autophagy adaptor,but its role in cardiac ischemia remains elusive.This study examined the role of TAX1BP1 in myocardial ischemic stress and the underlying mechanisms involved.Levels of TAX1BP1 were significantly downregulated in heart tissues of patients with ischemic heart disease and in a left anterior descending(LAD)ligation-induced model of acute MI.Adenovirus carrying TAX1BP1 was delivered into the myocardium.The acute MI induced procedure elicited an infarct and cardiac dysfunction,the effect of which was mitigated by TAX1BP1 overexpression with little effect from viral vector alone.TAX1BP1 nullified acute MI-induced activation of the NLRP3 inflammasome and associated mitochondrial dysfunction.TAX1BP1 overexpression suppressed NLRP3 mitochondrial localization by inhibiting the interaction of NLRP3 with mitochondrial antiviral signaling protein(MAVS).Further investigation revealed that ring finger protein 34(RNF34)was recruited to interact with TAX1BP1 thereby facilitating autophagic degradation of MAVS through K27-linked polyubiquitination of MAVS.Knockdown of RNF34 using siRNA nullified TAX1BP1 yielded protection against hypoxia-induced MAVS mitochondrial accumulation,NLRP3 inflammasome activation and associated loss of mitochondrial membrane potential.Taken together,our results favor a cardioprotective role for TAX1BP1 in acute MI through repression of inflammasome activation in a RNF34/MAVS-dependent manner.展开更多
文摘There are many kinds of Chinese patent medicine used to fight against influenza efficiently in clinical practice. However, little experimental data confirmed the anti-influenza the activities since non-suitable animal model and in vitro antiviral experiments. This paradox can be explained by host factors are important in the patho- genesis and outcome of influenza infection. Accordingly, we set up a mouse model by using restraint stress plus vi- ral infection, which is more conducive to simulate the clinical features of susceptible population and evaluate the activities of Chinese herbal medicine. Our results demonstrated that stress-induced corticosterone （CORT） , a stres- sor sensor, increased the morbidity and the mortality of virus infected mice loaded with restraint stress. CORT also increased expression of Mfn2, and accordingly decreased mitochondrial antiviral signaling （MAVS） aggregates in the host cells. Mfn2 overexpression increased NP and decreased IFN-β and IFITM3 protein expressions in influenza virus infected A549 cells. These findings suggested that the mechanism of restraint stress increased the susceptibili- ty due to CORT induces activation of Mfn2 mediated MAVS pathway.
基金Supported by The Natural Science Foundation of China,No.30600330,No.30671842,No.30672488,No.30700475,No.30771919and No.30700757the National High Technology Research and Development Program of China,No.2008AA02Z132+1 种基金Beijing Municipal Natural Science Foundation,No.5082016Mega-projects of Science Research for the 11th Five-Year Plan,No.2009ZX10004-4001
文摘AIM:To develop a sensitive assay for screening compounds against hepatitis C virus (HCV).METHODS:The proteolytic cleavage of NS3/4A on enhanced yellow fluorescent protein (eYFP)-mitochondrial antiviral signaling protein (MAVS) was examined by reporter enzyme secreted placental alkaline phosphatase (SEAP),which enabled us to perform ongoing monitoring of anti-HCV drugs through repeated chemiluminescence.Subcellular localization of eYFP-MAVS was assessed by fluorescence microscopy.Cellular localization and protein levels were examined by Western blotting.RESULTS:HCV NS3/4A protease cleaved eYFP-MAVSfrom mitochondria to block the activation of interferon (IFN)-β promoter,thus resulting in downregulation of SEAP activity.The decrease in SEAP activity was proportional to the dose of active NS3/4A protease.Also this reporter assay was used to detect anti-HCV activity of IFN-α and cyclosporine A.CONCLUSION:Our data show that this reporter system is a sensitive and quantitative reporter of anti-HCV inhibitors.This system will constitute a new tool to allow the efficient screening of HCV inhibitors.
文摘目的探讨乙型肝炎(乙肝)表面抗原(Hepatitis B surface antigen,HBsAg)阳性母亲乙肝病毒(Hepatitis B virus,HBV)DNA载量和婴儿出生时线粒体抗病毒信号蛋白(Mitochondrial antiviral signaling protein,MAVS)信号通路对婴儿接种乙肝疫苗(Hepatitis B vaccine,HepB)无/弱应答的影响。方法选择2019年11月至2022年6月太原市某医院分娩的HBsAg阳性母亲及其婴儿,检测母亲HBV DNA载量、婴儿出生时脐血免疫细胞比例和MAVS信号通路蛋白表达百分比、婴儿乙肝免疫球蛋白和HepB全程接种后1-2月血清乙肝表面抗体(Hepatitis B surface antibody,HBsAb)。采用多因素Logistic回归模型分析HBV DNA和MAVS信号通路对婴儿接种HepB无/弱应答的影响。结果婴儿HepB全程接种后无/弱应答率为14.38%(22/153)。多因素Logistic回归分析显示,母亲HBV DNA载量高、脐血MAVS、pIRF3和pNF-κB蛋白表达百分比低、脐血浆细胞比例低的婴儿HepB无/弱应答率高[OR(95%CI):3.94(1.11-14.00)、1.44(1.15-1.73)、4.17(1.16-14.96)、1.94(1.38-2.51)、3.97(1.14-13.79)]。结论HBsAg阳性母亲HBV DNA载量和婴儿出生时MAVS信号通路显著影响婴儿接种HepB的免疫应答;相关检测有助于识别HepB无/弱应答高危人群。
基金supported by the National Basic Research Program(973 Program)(Nos.2010CB529701 and 2012CB910204)the National Natural Science Foundation of China(Grant Nos.10979005 and 30970566)the Science and Technology Commission of Shanghai Municipality(11JC14140000).
文摘Retinoic acid-inducible gene I(RIG-I)is an important pattern recognition receptor that detects viral RNA and triggers the production of type-I interferons through the downstream adaptor MAVS(also called IPS-1,CARDIF,or VISA).A series of structural studies have elaborated some of the mechanisms of dsRNA recognition and activation of RIG-I.Recent studies have proposed that K63-linked ubiquitination of,or unanchored K63-linked polyubiquitin binding to RIG-I positively regulates MAVS-mediated antiviral signaling.Conversely phos-phorylation of RIG-I appears to play an inhibitory role in controlling RIG-I antiviral signal transduction.Here we performed a combined structural and biochemical study to further define the regulatory features of RIG-I signaling.ATP and dsRNA binding triggered dimeriza-tion of RIG-I with conformational rearrangements of the tandem CARD domains.Full length RIG-I appeared to form a complex with dsRNA in a 2:2 molar ratio.Com-pared with the previously reported crystal structures of RIG-I in inactive state,our electron microscopic struc-ture of full length RIG-I in complex with blunt-ended dsRNA,for the first time,revealed an exposed active conformation of the CARD domains.Moreover,we found that purified recombinant RIG-I proteins could bind to the CARD domain of MAVS independently of dsRNA,while S8E and T170E phosphorylation-mimick-ing mutants of RIG-I were defective in binding E3 ligase TRIM25,unanchored K63-linked polyubiquitin,and MAVS regardless of dsRNA.These findings suggested that phosphorylation of RIG inhibited downstream signaling by impairing RIG-I binding with polyubiquitin and its interaction with MAVS.
基金This work was supported by the National Natural Science Foundation of China(2017YFA0506001,81900233,81770261,81521001,and 91749128)the Postdoctoral Science Foundation of China(2019M661375).
文摘Acute myocardial infarction(MI),one of the most common cardiovascular emergencies,is a leading cause of morbidity and mortality.Ample evidence has revealed an essential role for inflammasome activation and autophagy in the pathogenesis of acute MI.Tax1-binding protein 1(TAX1BP1),an adaptor molecule involved in termination of proinflammatory signaling,serves as an important selective autophagy adaptor,but its role in cardiac ischemia remains elusive.This study examined the role of TAX1BP1 in myocardial ischemic stress and the underlying mechanisms involved.Levels of TAX1BP1 were significantly downregulated in heart tissues of patients with ischemic heart disease and in a left anterior descending(LAD)ligation-induced model of acute MI.Adenovirus carrying TAX1BP1 was delivered into the myocardium.The acute MI induced procedure elicited an infarct and cardiac dysfunction,the effect of which was mitigated by TAX1BP1 overexpression with little effect from viral vector alone.TAX1BP1 nullified acute MI-induced activation of the NLRP3 inflammasome and associated mitochondrial dysfunction.TAX1BP1 overexpression suppressed NLRP3 mitochondrial localization by inhibiting the interaction of NLRP3 with mitochondrial antiviral signaling protein(MAVS).Further investigation revealed that ring finger protein 34(RNF34)was recruited to interact with TAX1BP1 thereby facilitating autophagic degradation of MAVS through K27-linked polyubiquitination of MAVS.Knockdown of RNF34 using siRNA nullified TAX1BP1 yielded protection against hypoxia-induced MAVS mitochondrial accumulation,NLRP3 inflammasome activation and associated loss of mitochondrial membrane potential.Taken together,our results favor a cardioprotective role for TAX1BP1 in acute MI through repression of inflammasome activation in a RNF34/MAVS-dependent manner.
