Ring finger protein 122(RNF122),an E3 ubiquitin ligase,orchestrates antiviral immune responses in mammals by targeting retinoic acid-inducible gene 1 and melanoma differentiation-associated gene 5 for ubiquitination.H...Ring finger protein 122(RNF122),an E3 ubiquitin ligase,orchestrates antiviral immune responses in mammals by targeting retinoic acid-inducible gene 1 and melanoma differentiation-associated gene 5 for ubiquitination.However,its functional relevance in teleosts has yet to be clearly defined,particularly regarding the identification of substrate-specific regulatory sites.This study characterized RNF122 from mandarin fish(Siniperca chuatsi),termed scRNF122,and investigated its regulatory impact on stimulator of interferon genes(STING)-mediated antiviral signaling.Results showed that scRNF122 expression was up-regulated in response to mandarin fish ranavirus(MRV)infection,and its overexpression suppressed scSTING-mediated interferon(IFN)production and enhanced MRV replication.Co-immunoprecipitation confirmed a direct interaction between scRNF122 and scSTING.Functional assays demonstrated that scRNF122 facilitated scSTING degradation through the ubiquitin-proteasome pathway,a process impeded by MG132 treatment.Ubiquitination analyses of various scSTING mutants revealed that scRNF122 catalyzed scSTING ubiquitination at K95,K117,and K155 residues.Moreover,scRNF122 significantly impaired scSTING-dependent antiviral responses by engaging negative regulatory elements within the signaling cascade.Overall,scRNF122 was identified as a negative modulator of STING-mediated IFN signaling in mandarin fish,diminishing STING-dependent antiviral activity and promoting its degradation via the ubiquitin-proteasome pathway at lysine residues K95,K117,and K155.These findings provide mechanistic insight into the post-translational control of STING in teleosts and establish a foundation for future investigations into antiviral immune regulation.展开更多
文摘目的 探讨经颅多普勒超声(transcranial Doppler,TCD)、微小核糖核酸(microribonucleic acid,miR)-122a、核苷酸结合寡聚化结构域样受体蛋白3(nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)及其联合检测在脓毒症相关性脑病(sepsis-associated encephalopathy,SAE)中的诊断价值。方法选取2022年2月至2024年2月期间,由河南大学第一附属医院收治的共计89例脓毒症患者作为观察对象,根据是否发生SAE,将其划分为脓毒症脑病组(n=29)与非脓毒症脑病组(n=60)。所有入选患者接受TCD检查,同时检测了其血清中miR-122a以及NLRP3炎症小体的表达水平。采用Pearson相关性分析法和受试者工作特征(receiver operating characteristic,ROC)曲线对这些指标在脓毒症患者SAE诊断中的价值进行评估。结果脓毒症脑病组急性生理与慢性健康评分系统Ⅱ(acute physiology and chronic health evaluationⅡ,APACHEⅡ)评分、平均血流速度(mean flow velocity,Vm)、搏动指数(pulsatility index,PI)值、血清NLRP3炎性小体、miR-122a水平均较非脓毒症脑病组偏高,格拉斯哥昏迷量表(Glasgow coma scale,GCS)评分、收缩期峰值流速(peak systolic velocity,Vs)、舒张末期流速(end-diastolic velocity,Vd)值均较非脓毒症脑病组偏低,差异有统计学意义(P<0.05)。SAE患者Vd、Vs及Vm与APACHEⅡ评分均呈负相关,PI、血清miR-122a及NLRP3炎性小体水平与APACHEⅡ评分均呈正相关(P<0.05);Vd、Vm、Vs、NLRP3炎性小体及miR-122a水平均与GCS评分均呈正相关,PI与GCS评分呈负相关(P<0.05)。Vm、PI、NLRP3炎性小体及miR-122a水平均是影响脓毒症患者并发脑病的独立危险因素(P<0.05),Vm、PI、血清miR-122a及NLRP3炎性小体水平单独检测诊断脓毒性相关脑病的曲线下面积(area under the curve,AUC)分别为0.763(0.655~0.872)、0.809(0.712~0.907)、0.754(0.642~0.866)和0.844(0.753~0.935),其敏感度分别为0.626、0.812、0.555和0.844;特异度为0.801、0.680、0.751和0.751。联合检测的AUC为0.902(0.832~0.971),其敏感度和特异度分别为0.938和0.755。结论TCD联合血清miR-122a和NLRP3炎性小体水平检测对SAE具有较高的诊断价值,可为临床早期筛查脓毒症相关性脑病提供新思路。
基金supported by the National Key Research and Development Program of China(2022YFE0203900,2024YFD2401101)China Agriculture Research System(CARS-46)+1 种基金National Natural Science Foundation of China(32473201)Guangdong S&T Program(2022B1111030001,2024B1212040007)。
文摘Ring finger protein 122(RNF122),an E3 ubiquitin ligase,orchestrates antiviral immune responses in mammals by targeting retinoic acid-inducible gene 1 and melanoma differentiation-associated gene 5 for ubiquitination.However,its functional relevance in teleosts has yet to be clearly defined,particularly regarding the identification of substrate-specific regulatory sites.This study characterized RNF122 from mandarin fish(Siniperca chuatsi),termed scRNF122,and investigated its regulatory impact on stimulator of interferon genes(STING)-mediated antiviral signaling.Results showed that scRNF122 expression was up-regulated in response to mandarin fish ranavirus(MRV)infection,and its overexpression suppressed scSTING-mediated interferon(IFN)production and enhanced MRV replication.Co-immunoprecipitation confirmed a direct interaction between scRNF122 and scSTING.Functional assays demonstrated that scRNF122 facilitated scSTING degradation through the ubiquitin-proteasome pathway,a process impeded by MG132 treatment.Ubiquitination analyses of various scSTING mutants revealed that scRNF122 catalyzed scSTING ubiquitination at K95,K117,and K155 residues.Moreover,scRNF122 significantly impaired scSTING-dependent antiviral responses by engaging negative regulatory elements within the signaling cascade.Overall,scRNF122 was identified as a negative modulator of STING-mediated IFN signaling in mandarin fish,diminishing STING-dependent antiviral activity and promoting its degradation via the ubiquitin-proteasome pathway at lysine residues K95,K117,and K155.These findings provide mechanistic insight into the post-translational control of STING in teleosts and establish a foundation for future investigations into antiviral immune regulation.
