目的研究环指蛋白34(RING finger protein 34,RNF34)对天然免疫的调控。方法利用重组PCR方法构建pcDNA3-Flag-RNF34、pcDNA3-Flag-RNF34-ΔFYVE、pcDNA3-Flag-RNF34-ΔCID和pcDNA3-Flag-RNF34-ΔRING质粒,并在HEK293T细胞中瞬时表达;利...目的研究环指蛋白34(RING finger protein 34,RNF34)对天然免疫的调控。方法利用重组PCR方法构建pcDNA3-Flag-RNF34、pcDNA3-Flag-RNF34-ΔFYVE、pcDNA3-Flag-RNF34-ΔCID和pcDNA3-Flag-RNF34-ΔRING质粒,并在HEK293T细胞中瞬时表达;利用双荧光素酶报告基因技术检测RNF34及其3种突变体对仙台病毒(SeV)和N-RIG-Ⅰ激活NF-κB和IFN-β转录活性的影响。结果成功构建了Flag-RNF34及其3种结构域缺失突变体的真核表达质粒;发现在SeV刺激下,RNF34对NF-κB和IFN-β转录活性有明显抑制作用,RNF34-ΔFYVE、RNF34-ΔCID和RNF34-ΔRING与RNF34相比此种抑制作用减弱。同时发现对于N-RIG-Ⅰ激活的NF-κB和IFN-β活性,RNF34及其3种结构域缺失突变体也有相似的抑制作用。结论 RNF34通过负调控RIG-Ⅰ-MAVS信号通路调控天然免疫。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
文摘目的研究环指蛋白34(RING finger protein 34,RNF34)对天然免疫的调控。方法利用重组PCR方法构建pcDNA3-Flag-RNF34、pcDNA3-Flag-RNF34-ΔFYVE、pcDNA3-Flag-RNF34-ΔCID和pcDNA3-Flag-RNF34-ΔRING质粒,并在HEK293T细胞中瞬时表达;利用双荧光素酶报告基因技术检测RNF34及其3种突变体对仙台病毒(SeV)和N-RIG-Ⅰ激活NF-κB和IFN-β转录活性的影响。结果成功构建了Flag-RNF34及其3种结构域缺失突变体的真核表达质粒;发现在SeV刺激下,RNF34对NF-κB和IFN-β转录活性有明显抑制作用,RNF34-ΔFYVE、RNF34-ΔCID和RNF34-ΔRING与RNF34相比此种抑制作用减弱。同时发现对于N-RIG-Ⅰ激活的NF-κB和IFN-β活性,RNF34及其3种结构域缺失突变体也有相似的抑制作用。结论 RNF34通过负调控RIG-Ⅰ-MAVS信号通路调控天然免疫。
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.
