Tripartite motif containing 22 (TRIM22), a member of the TRIM/RBCC family, has been reported to activate the nuclear factor-kappa B (NF-κB) pathway in unstimulated macrophage cell lines, but the detailed mechanisms g...Tripartite motif containing 22 (TRIM22), a member of the TRIM/RBCC family, has been reported to activate the nuclear factor-kappa B (NF-κB) pathway in unstimulated macrophage cell lines, but the detailed mechanisms governing this activation remains unclear. We investigated this mechanism in HEK293T cells. We found that overexpression of TRIM22 could activate the NF-κB pathway and conversely, could inhibit the tumor necrosis factor receptor-associated factor 6 (TRAF6)-stimulated NF-κB pathway in HEK293T cells. Further experiments showed that TRIM22 could decrease the self-ubiquitination of TRAF6, and interact with and degrade transforming growth factor-β activated kinase 1 binding protein 2 (TAB2), and that these effects could be partially rescued by a TRIM22 RING domain deletion mutant. Collectively, our data indicate that overexpression of TRIM22 may negatively regulate the TRAF6-stimulated NF-κB pathway by interacting with and degrading TAB2.展开更多
目的比较和分析Rpl32和Rpl13作为单内参基因与两者作为双内参基因,用于检测大鼠挫伤肌肉组织中TAB2 m RNA表达量的结果。方法 78只SD大鼠,随机分为正常对照组(1组)和肌肉损伤组(12组)。采用自由落体法制作大鼠肌肉挫伤模型,分别于4h^48...目的比较和分析Rpl32和Rpl13作为单内参基因与两者作为双内参基因,用于检测大鼠挫伤肌肉组织中TAB2 m RNA表达量的结果。方法 78只SD大鼠,随机分为正常对照组(1组)和肌肉损伤组(12组)。采用自由落体法制作大鼠肌肉挫伤模型,分别于4h^48h之间12个时间点取肌肉组织,提取总RNA、合成c DNA、采用real-time q PCR法,以Rpl32和Rpl13作为单独内参基因和二者作为双内参基因检测大鼠肌肉挫伤组织中TAB2 m RNA相对表达量,并计算检测结果的变异系数。结果以Rpl32或Rpl13单独作为内参基因或作为双内参基因,TAB2 m RNA表达随损伤时间总体均呈现降低的变化规律,但使用单内参基因在24h和32h出现极高值,而用双内参基因计算未出现极值,且各结果的变异系数均较小。结论 Rpl32和Rpl13作为双内参基因用于计算TAB2 m RNA相对表达量,可提高分析结果的准确性,在相关实验中建议选择使用。展开更多
Traumatic brain injury(TBI)triggers the activation of the endogenous coagulation mechanism,and a large amount of thrombin is released to curb uncontrollable bleeding through thrombin receptors,also known as protease-a...Traumatic brain injury(TBI)triggers the activation of the endogenous coagulation mechanism,and a large amount of thrombin is released to curb uncontrollable bleeding through thrombin receptors,also known as protease-activated receptors(PARs).However,thrombin is one of the most critical factors in secondary brain injury.Thus,the PARs may be effective targets against hemorrhagic brain injury.Since the PAR1 antagonist has an increased bleeding risk in clinical practice,PAR4 blockade has been suggested as a more promising treatment.Here,we explored the expression pattern of PAR4 in the brain of mice after TBI,and explored the effect and possible mechanism of BMS-986120(BMS),a novel selective and reversible PAR4 antagonist on secondary brain injury.Treatment with BMS protected against TBI in mice.mRNA-seq analysis,Western blot,and qRT-PCR verification in vitro showed that BMS significantly inhibited thrombin-induced inflammation in astrocytes,and suggested that the Tab2/ERK/NF-κB signaling pathway plays a key role in this process.Our findings provide reliable evidence that blocking PAR4 is a safe and effective intervention for TBI,and suggest that BMS has a potential clinical application in the management of TBI.展开更多
Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications,including ubiquitination,SUMOylation,a...Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications,including ubiquitination,SUMOylation,and phosphorylation;however,the underlying molecular mechanism is not fully understood.In this study,TRIM60 negatively regulated the formation and activation of the TAK1 signalosome.Deficiency of TRIM60 in macrophages led to enhanced MAPK and NF-κB activation,accompanied by elevated levels of proinflammatory cytokines but not IFN-I.Immunoprecipitation-mass spectrometry assays identified TAB2 as the target of TRIM60 for SUMOylation rather than ubiquitination,resulting in impaired formation of the TRAF6/TAB2/TAK1 complex and downstream MAPK and NF-κB pathways.The SUMOylation sites of TAB2 mediated by TRIM60 were identified as K329 and K562;substitution of these lysines with arginines abolished the SUMOylation of TAB2.In vivo experiments showed that TRIM60-deficient mice showed an elevated immune response to LPS-induced septic shock and L.monocytogenes infection.Our data reveal that SUMOylation of TAB2 mediated by TRIM60 is a novel mechanism for regulating the innate immune response,potentially paving the way for a new strategy to control antibacterial immune responses.展开更多
Although microRNA-155(miR-155)is considered a pro-inflammatory mediator,cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells.In this study,we identified the drama...Although microRNA-155(miR-155)is considered a pro-inflammatory mediator,cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells.In this study,we identified the dramatic expression changes of more than half of potential miR-155-targeted genes upon lipopolysaccharide(LPS)stimulation;223 genes were down-regulated and 85 genes were up-regulated,including suppressor of cytokine signaling 1(SOCS1)and transforming growth factor-β-activated kinase 1-binding protein 2(TAB2),two well-known genes involved in miR-155-mediated regulation of the Toll-like receptor 4(TLR4)signaling pathway.We also found that miR-155 acted as an anti-inflammatory mediator in the initial stage of LPS-induced inflammatory response mainly through repressing TAB2 protein translation,and as a proinflammatory mediator by down-regulating SOCS1 in the later stage.Meanwhile,overexpression of TAB23'untranslated region(UTR)in macrophages promoted the development of endotoxin tolerance by competing for binding with miR-155,which resulted in an elevated expression level of SOCS1 protein.These findings provide new insights for understanding the regulatory mechanisms in fine-tuning of LPS-induced innate immune response.展开更多
Nonalcoholic steatohepatitis(NASH)has emerged as the major cause of end-stage liver diseases.However,an incomplete understanding of its molecular mechanisms severely dampens the development of pharmacotherapies.In the...Nonalcoholic steatohepatitis(NASH)has emerged as the major cause of end-stage liver diseases.However,an incomplete understanding of its molecular mechanisms severely dampens the development of pharmacotherapies.In the present study,through systematic screening of genome-wide mRNA expression from three mouse models of hepatic inflammation and fibrosis,we identified IGF2BP2,an N6-methyladenosine modification reader,as a key regulator that promotes NASH progression in mice.Adenovirus or adeno-associated virus-mediated overexpression of IGF2BP2 could induce liver steatosis,inflammation,and fibrosis in mice,at least in part,by increasing Tab2 mRNA stability.Besides,hepatic overexpression of IGF2BP2 mimicked gene expression profiles and molecular pathways of human NASH livers.Of potential clinical significance,IGF2BP2 expression is significantly upregulated in the livers of NASH patients.Moreover,knockdown of IGF2BP2 substantially alleviated liver injury,inflammation,and fibrosis in diet-induced NASH mice.Taken together,our findings reveal an important role of IGF2BP2 in NASH,which may provide a new therapeutic target for the treatment of NASH.展开更多
基金supported by a grant from the Key Projects in the National Science & Technology Pillar Program during the twelfth Five-Year Plan Period of China (2012ZX10001006-002)grants from the International Science & Technology Cooperation Program of China (2011DFA31030)Deutsche Forschungsgemeinschaft (SFB/Transregio TRR60)and Key Laboratory on Emerging Infectious Diseases and Biosafety in Wuhan
文摘Tripartite motif containing 22 (TRIM22), a member of the TRIM/RBCC family, has been reported to activate the nuclear factor-kappa B (NF-κB) pathway in unstimulated macrophage cell lines, but the detailed mechanisms governing this activation remains unclear. We investigated this mechanism in HEK293T cells. We found that overexpression of TRIM22 could activate the NF-κB pathway and conversely, could inhibit the tumor necrosis factor receptor-associated factor 6 (TRAF6)-stimulated NF-κB pathway in HEK293T cells. Further experiments showed that TRIM22 could decrease the self-ubiquitination of TRAF6, and interact with and degrade transforming growth factor-β activated kinase 1 binding protein 2 (TAB2), and that these effects could be partially rescued by a TRIM22 RING domain deletion mutant. Collectively, our data indicate that overexpression of TRIM22 may negatively regulate the TRAF6-stimulated NF-κB pathway by interacting with and degrading TAB2.
文摘目的比较和分析Rpl32和Rpl13作为单内参基因与两者作为双内参基因,用于检测大鼠挫伤肌肉组织中TAB2 m RNA表达量的结果。方法 78只SD大鼠,随机分为正常对照组(1组)和肌肉损伤组(12组)。采用自由落体法制作大鼠肌肉挫伤模型,分别于4h^48h之间12个时间点取肌肉组织,提取总RNA、合成c DNA、采用real-time q PCR法,以Rpl32和Rpl13作为单独内参基因和二者作为双内参基因检测大鼠肌肉挫伤组织中TAB2 m RNA相对表达量,并计算检测结果的变异系数。结果以Rpl32或Rpl13单独作为内参基因或作为双内参基因,TAB2 m RNA表达随损伤时间总体均呈现降低的变化规律,但使用单内参基因在24h和32h出现极高值,而用双内参基因计算未出现极值,且各结果的变异系数均较小。结论 Rpl32和Rpl13作为双内参基因用于计算TAB2 m RNA相对表达量,可提高分析结果的准确性,在相关实验中建议选择使用。
基金This work was supported by grants from the National Natural Science Foundation of China(81630027,81571215)the Chang Jiang Scholar Program of China。
文摘Traumatic brain injury(TBI)triggers the activation of the endogenous coagulation mechanism,and a large amount of thrombin is released to curb uncontrollable bleeding through thrombin receptors,also known as protease-activated receptors(PARs).However,thrombin is one of the most critical factors in secondary brain injury.Thus,the PARs may be effective targets against hemorrhagic brain injury.Since the PAR1 antagonist has an increased bleeding risk in clinical practice,PAR4 blockade has been suggested as a more promising treatment.Here,we explored the expression pattern of PAR4 in the brain of mice after TBI,and explored the effect and possible mechanism of BMS-986120(BMS),a novel selective and reversible PAR4 antagonist on secondary brain injury.Treatment with BMS protected against TBI in mice.mRNA-seq analysis,Western blot,and qRT-PCR verification in vitro showed that BMS significantly inhibited thrombin-induced inflammation in astrocytes,and suggested that the Tab2/ERK/NF-κB signaling pathway plays a key role in this process.Our findings provide reliable evidence that blocking PAR4 is a safe and effective intervention for TBI,and suggest that BMS has a potential clinical application in the management of TBI.
基金This study was supported by grants from the Ministry of Science and Technology(National Key Research and Development Program 2016YFA0502203,2016YFA0502201,2019YFA0110201,2019YFA0110203,2018YFE0204500,and 2018YFC1004601)the National Natural Science Foundation of China(91740111,81871232 and 31870881)the 1.3.5 Project of Disciplines of Excellence and National Clinical Research Center for Geriatrics(Z20201001),West China Hospital,Sichuan University.
文摘Activation of the TAK1 signalosome is crucial for mediating the innate immune response to pathogen invasion and is regulated by multiple layers of posttranslational modifications,including ubiquitination,SUMOylation,and phosphorylation;however,the underlying molecular mechanism is not fully understood.In this study,TRIM60 negatively regulated the formation and activation of the TAK1 signalosome.Deficiency of TRIM60 in macrophages led to enhanced MAPK and NF-κB activation,accompanied by elevated levels of proinflammatory cytokines but not IFN-I.Immunoprecipitation-mass spectrometry assays identified TAB2 as the target of TRIM60 for SUMOylation rather than ubiquitination,resulting in impaired formation of the TRAF6/TAB2/TAK1 complex and downstream MAPK and NF-κB pathways.The SUMOylation sites of TAB2 mediated by TRIM60 were identified as K329 and K562;substitution of these lysines with arginines abolished the SUMOylation of TAB2.In vivo experiments showed that TRIM60-deficient mice showed an elevated immune response to LPS-induced septic shock and L.monocytogenes infection.Our data reveal that SUMOylation of TAB2 mediated by TRIM60 is a novel mechanism for regulating the innate immune response,potentially paving the way for a new strategy to control antibacterial immune responses.
基金the National Natural Science Foundation of China(Nos.81701568,81930041,81571524,81872248,and 91842103)the Zhejiang Provincial Natural Science Foundation of China(Nos.Y15C080001 and Z19H100001)the Zhejiang Provincial Key Laboratory for Immunity and Inflammatory Diseases for its support。
文摘Although microRNA-155(miR-155)is considered a pro-inflammatory mediator,cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells.In this study,we identified the dramatic expression changes of more than half of potential miR-155-targeted genes upon lipopolysaccharide(LPS)stimulation;223 genes were down-regulated and 85 genes were up-regulated,including suppressor of cytokine signaling 1(SOCS1)and transforming growth factor-β-activated kinase 1-binding protein 2(TAB2),two well-known genes involved in miR-155-mediated regulation of the Toll-like receptor 4(TLR4)signaling pathway.We also found that miR-155 acted as an anti-inflammatory mediator in the initial stage of LPS-induced inflammatory response mainly through repressing TAB2 protein translation,and as a proinflammatory mediator by down-regulating SOCS1 in the later stage.Meanwhile,overexpression of TAB23'untranslated region(UTR)in macrophages promoted the development of endotoxin tolerance by competing for binding with miR-155,which resulted in an elevated expression level of SOCS1 protein.These findings provide new insights for understanding the regulatory mechanisms in fine-tuning of LPS-induced innate immune response.
基金This study was supported by the National Key Research and Development Program of China(2018YFA0800402)the Shanghai Outstanding Academic Leaders Projects(21XD1423400)+3 种基金the Basic Research of Science,and Technology Innovation Action Plan(21JC1401300)Shanghai Sailing Program by Shanghai Municipal Science and Technology Committee(22YF1432800)China Postdoctoral Science Foundation Funded Project(2021M702183)the Youth Cultivation Project of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital(ynqn202107).
文摘Nonalcoholic steatohepatitis(NASH)has emerged as the major cause of end-stage liver diseases.However,an incomplete understanding of its molecular mechanisms severely dampens the development of pharmacotherapies.In the present study,through systematic screening of genome-wide mRNA expression from three mouse models of hepatic inflammation and fibrosis,we identified IGF2BP2,an N6-methyladenosine modification reader,as a key regulator that promotes NASH progression in mice.Adenovirus or adeno-associated virus-mediated overexpression of IGF2BP2 could induce liver steatosis,inflammation,and fibrosis in mice,at least in part,by increasing Tab2 mRNA stability.Besides,hepatic overexpression of IGF2BP2 mimicked gene expression profiles and molecular pathways of human NASH livers.Of potential clinical significance,IGF2BP2 expression is significantly upregulated in the livers of NASH patients.Moreover,knockdown of IGF2BP2 substantially alleviated liver injury,inflammation,and fibrosis in diet-induced NASH mice.Taken together,our findings reveal an important role of IGF2BP2 in NASH,which may provide a new therapeutic target for the treatment of NASH.
