TDP-43 proteinopathies and cryptic exons:Transactive response DNA binding protein of 43 kDa(TDP-43)is a ubiquitously expressed RNA/DNA binding protein crucial for coding and non-coding RNA metabolism including transcr...TDP-43 proteinopathies and cryptic exons:Transactive response DNA binding protein of 43 kDa(TDP-43)is a ubiquitously expressed RNA/DNA binding protein crucial for coding and non-coding RNA metabolism including transcription,splicing,transport,translation,and turnover.TDP-43 shuttles between the nucleus and cytoplasm,but is predominantly localized in the nucleus.Neurodegenerative diseases(NDs)may be accompanied by nuclear loss and possible cytoplasmic accumulation and aggregation of TDP-43 in vulnerable neurons and beyond.This neuropathology is the hallmark of most individuals suffering from amyotrophic lateral sclerosis(ALS),frontotemporal dementia(FTD)with TDP-43-immunoreactive pathology(FTD-TDP),limbic-predominant age-related TDP-43 encephalopathy(LATE)and Perry syndrome,but also coexists with the primary pathology in subsets of patients suffering from other NDs,such as Alzheimer’s disease,Lewy body dementias,or Huntington’s disease.Variants in the gene encoding TDP-43(TARDBP)are the cause of ALS and/or FTD in some rare cases substantiating the importance of this protein in aging neurons.It is still controversial if loss of nuclear,or increased cytoplasmic and/or aggregating TDP-43 is more harmful to neurons(Nag and Schneider,2023).Recently,the role of nuclear TDP-43 in repressing the inclusion of intronic sequences,named cryptic exons(CEs),into mature mRNAs gained much attention.展开更多
目的探索TAR DNA结合蛋白43(transactive response DNA binding protein 43,TDP-43)在氧化应激诱导的小鼠神经元(neuro-2a,N2a)细胞损伤及小鼠痛觉敏化中的作用及机制。方法①为评估最佳诱导浓度,不同浓度的H_(2)O_(2)处理N2a细胞分为4...目的探索TAR DNA结合蛋白43(transactive response DNA binding protein 43,TDP-43)在氧化应激诱导的小鼠神经元(neuro-2a,N2a)细胞损伤及小鼠痛觉敏化中的作用及机制。方法①为评估最佳诱导浓度,不同浓度的H_(2)O_(2)处理N2a细胞分为4组:对照组、200μmol/L H_(2)O_(2)组、400μmol/L H_(2)O_(2)组和800μmol/L H_(2)O_(2)组。②为评估最佳诱导时间,400μmol/L H_(2)O_(2)处理N2a细胞分为4组:对照组、6 h H_(2)O_(2)组、12 h H_(2)O_(2)组和24 h H_(2)O_(2)组。③为验证线粒体DNA(mitochondria DNA,mtDNA)释放途径,使用环孢素(cyclosporin,CsA)抑制线粒体通透性转换孔(mitochondrial permeability transition pore,mPTP)分为3组:对照组、24 h H_(2)O_(2)组和24 h H_(2)O_(2)+CsA组。④为验证TDP-43介导的细胞损伤机制,siRNA抑制TDP-43后分为3组:对照组、24 h H_(2)O_(2)组、24 h H_(2)O_(2)+siTDP-43组。⑤采用CCK-8检测细胞活性,EdU检测细胞增殖,Western blot检测TDP-43、神经元标志物(neuronal nuclei,NeuN)、环状GMP-AMP合酶(cylic GMP-AMP synthase,cGAS)和干扰素基因刺激因子(stimulator of interferon,STING)表达,qPCR检测mtDNA,免疫染色观察细胞内TDP-43表达变化,Calcein AM染色评估mPTP开放。⑥为验证TDP-43在神经病理性疼痛(neuropathic pain,NP)中的作用,将24只6~8周健康SPF级雄性C57BL/6J小鼠(体质量25~30 g)使用随机数字表法分为3组:对照组、慢性压迫性损伤(chronic constriction injury,CCI)组、CCI+siTDP-43组,术前1 d和术后7、14、21 d进行鞘内注射siTDP-43;术前1 d和术后1、3、5、7、14、21 d通过von Frey纤维丝和热辐射法测定小鼠机械痛阈值和热痛阈值,免疫荧光检测术后21 d腰段(L5-L6)脊髓背角中TDP-43与NeuN的变化。结果氧化应激刺激诱导N2a中TDP-43蛋白表达增加,刺激mtDNA通过mPTP释放,上调cGAS、STING的表达,影响N2a的细胞活性(P<0.05);CsA抑制mPTP通道的开放并减少mtDNA释放(P<0.05);下调TDP-43的表达后可显著降低mtDNA的释放,抑制cGAS和STING的表达,并恢复N2a细胞的增殖能力(P<0.05)。CCI术后5 d,小鼠机械痛阈值和热痛阈值出现明显下降并持续至21 d(P<0.05);CCI小鼠术后21 d脊髓背角神经元中TDP-43表达增加(P<0.05);鞘内注射siRNA抑制TDP-43后,可提高CCI小鼠的机械痛阈值和热痛阈值(P<0.05)。结论氧化应激诱导神经元细胞TDP-43蛋白增加,刺激mtDNA通过mPTP释放到细胞质,激活cGAS/STING通路,导致神经元损伤并加重CCI小鼠痛觉敏化。展开更多
TDP-43(Transactive response DNA binding protein 43, TDP-43)最初被认为是神经退行性疾病的病理学标记蛋白,研究发现其参与脑缺血损伤的发生发展。在现有研究的基础上,简要介绍TDP-43的结构与功能以及TDP-43在脑缺血后的表达变化及...TDP-43(Transactive response DNA binding protein 43, TDP-43)最初被认为是神经退行性疾病的病理学标记蛋白,研究发现其参与脑缺血损伤的发生发展。在现有研究的基础上,简要介绍TDP-43的结构与功能以及TDP-43在脑缺血后的表达变化及其在脑缺血后调节炎症反应、线粒体功能障碍、自噬等方面的作用。展开更多
基金supported by the Deutsche Forschungsgemeinschaft(DFGgrant#521487152)(to AF)。
文摘TDP-43 proteinopathies and cryptic exons:Transactive response DNA binding protein of 43 kDa(TDP-43)is a ubiquitously expressed RNA/DNA binding protein crucial for coding and non-coding RNA metabolism including transcription,splicing,transport,translation,and turnover.TDP-43 shuttles between the nucleus and cytoplasm,but is predominantly localized in the nucleus.Neurodegenerative diseases(NDs)may be accompanied by nuclear loss and possible cytoplasmic accumulation and aggregation of TDP-43 in vulnerable neurons and beyond.This neuropathology is the hallmark of most individuals suffering from amyotrophic lateral sclerosis(ALS),frontotemporal dementia(FTD)with TDP-43-immunoreactive pathology(FTD-TDP),limbic-predominant age-related TDP-43 encephalopathy(LATE)and Perry syndrome,but also coexists with the primary pathology in subsets of patients suffering from other NDs,such as Alzheimer’s disease,Lewy body dementias,or Huntington’s disease.Variants in the gene encoding TDP-43(TARDBP)are the cause of ALS and/or FTD in some rare cases substantiating the importance of this protein in aging neurons.It is still controversial if loss of nuclear,or increased cytoplasmic and/or aggregating TDP-43 is more harmful to neurons(Nag and Schneider,2023).Recently,the role of nuclear TDP-43 in repressing the inclusion of intronic sequences,named cryptic exons(CEs),into mature mRNAs gained much attention.
文摘目的探索TAR DNA结合蛋白43(transactive response DNA binding protein 43,TDP-43)在氧化应激诱导的小鼠神经元(neuro-2a,N2a)细胞损伤及小鼠痛觉敏化中的作用及机制。方法①为评估最佳诱导浓度,不同浓度的H_(2)O_(2)处理N2a细胞分为4组:对照组、200μmol/L H_(2)O_(2)组、400μmol/L H_(2)O_(2)组和800μmol/L H_(2)O_(2)组。②为评估最佳诱导时间,400μmol/L H_(2)O_(2)处理N2a细胞分为4组:对照组、6 h H_(2)O_(2)组、12 h H_(2)O_(2)组和24 h H_(2)O_(2)组。③为验证线粒体DNA(mitochondria DNA,mtDNA)释放途径,使用环孢素(cyclosporin,CsA)抑制线粒体通透性转换孔(mitochondrial permeability transition pore,mPTP)分为3组:对照组、24 h H_(2)O_(2)组和24 h H_(2)O_(2)+CsA组。④为验证TDP-43介导的细胞损伤机制,siRNA抑制TDP-43后分为3组:对照组、24 h H_(2)O_(2)组、24 h H_(2)O_(2)+siTDP-43组。⑤采用CCK-8检测细胞活性,EdU检测细胞增殖,Western blot检测TDP-43、神经元标志物(neuronal nuclei,NeuN)、环状GMP-AMP合酶(cylic GMP-AMP synthase,cGAS)和干扰素基因刺激因子(stimulator of interferon,STING)表达,qPCR检测mtDNA,免疫染色观察细胞内TDP-43表达变化,Calcein AM染色评估mPTP开放。⑥为验证TDP-43在神经病理性疼痛(neuropathic pain,NP)中的作用,将24只6~8周健康SPF级雄性C57BL/6J小鼠(体质量25~30 g)使用随机数字表法分为3组:对照组、慢性压迫性损伤(chronic constriction injury,CCI)组、CCI+siTDP-43组,术前1 d和术后7、14、21 d进行鞘内注射siTDP-43;术前1 d和术后1、3、5、7、14、21 d通过von Frey纤维丝和热辐射法测定小鼠机械痛阈值和热痛阈值,免疫荧光检测术后21 d腰段(L5-L6)脊髓背角中TDP-43与NeuN的变化。结果氧化应激刺激诱导N2a中TDP-43蛋白表达增加,刺激mtDNA通过mPTP释放,上调cGAS、STING的表达,影响N2a的细胞活性(P<0.05);CsA抑制mPTP通道的开放并减少mtDNA释放(P<0.05);下调TDP-43的表达后可显著降低mtDNA的释放,抑制cGAS和STING的表达,并恢复N2a细胞的增殖能力(P<0.05)。CCI术后5 d,小鼠机械痛阈值和热痛阈值出现明显下降并持续至21 d(P<0.05);CCI小鼠术后21 d脊髓背角神经元中TDP-43表达增加(P<0.05);鞘内注射siRNA抑制TDP-43后,可提高CCI小鼠的机械痛阈值和热痛阈值(P<0.05)。结论氧化应激诱导神经元细胞TDP-43蛋白增加,刺激mtDNA通过mPTP释放到细胞质,激活cGAS/STING通路,导致神经元损伤并加重CCI小鼠痛觉敏化。
文摘TDP-43(Transactive response DNA binding protein 43, TDP-43)最初被认为是神经退行性疾病的病理学标记蛋白,研究发现其参与脑缺血损伤的发生发展。在现有研究的基础上,简要介绍TDP-43的结构与功能以及TDP-43在脑缺血后的表达变化及其在脑缺血后调节炎症反应、线粒体功能障碍、自噬等方面的作用。
