目的探讨视黄酸受体α(retinoic acid receptorα,RARα)信号变化通过调控视皮质轴突蛋白1(neurexin 1,NRXN1)参与维生素A缺乏(vitamin A deficiency,VAD)大鼠孤独症样行为的机制。方法构建孕期开始的维生素A正常(vitamin A normal,VAN)...目的探讨视黄酸受体α(retinoic acid receptorα,RARα)信号变化通过调控视皮质轴突蛋白1(neurexin 1,NRXN1)参与维生素A缺乏(vitamin A deficiency,VAD)大鼠孤独症样行为的机制。方法构建孕期开始的维生素A正常(vitamin A normal,VAN)和VAD母鼠模型,并在生后早期对部分VAD母鼠和仔鼠给予维生素A补充(vitamin A supplement,VAS)。各组仔鼠(n=20)于6周龄进行行为学检测,利用三箱和旷场实验检测各组仔鼠社交行为和重复刻板行为;采用高效液相色谱法检测各组仔鼠血清视黄醇水平;采用电生理实验检测各组仔鼠视皮质的长时程增强(long-term potentiation,LTP)水平;采用实时荧光定量PCR法和Western blot法检测RARα、NRXN1和N-甲基-D-天冬氨酸受体1(N-methyl-D-aspartate receptor subunit 1,NMDAR1)的表达水平;采用染色质免疫共沉淀技术检测RARα转录因子在NRXN1基因启动子区的富集量。结果VAD组仔鼠出现社会交往障碍、重复刻板等孤独症样行为表现,生后开始的VAS可改善仔鼠大部分行为缺陷。VAD组仔鼠血清视黄醇水平明显低于VAN组和VAS组(P<0.05)。VAD组仔鼠视皮质NMDAR1、RARα和NRXN1的mRNA和蛋白表达水平及LTP水平均较VAN组和VAS组显著降低(P<0.05)。VAD组仔鼠视皮质中RARα转录因子在NRXN1基因启动子区的富集量较VAN组和VAS组显著下降(P<0.05)。结论RARα通过调控NRXN1影响VAD大鼠视皮质突触可塑性,从而参与VAD大鼠孤独症样行为的形成。[中国当代儿科杂志,2022,24(8):928-935]展开更多
The thymine DNA glycosylase （TDG） is a multifunctional enzyme,which is essential for embryonic development.It mediates the base excision repair （BER） of G：T and G：U DNA mismatches arising from the deamination of...The thymine DNA glycosylase （TDG） is a multifunctional enzyme,which is essential for embryonic development.It mediates the base excision repair （BER） of G：T and G：U DNA mismatches arising from the deamination of 5-methyl cytosine （5-MeC） and cytosine,respectively.Recent studies have pointed at a role of TDG during the active demethylation of 5-MeC within CpG islands.TDG interacts with the histone acetylase CREB-binding protein （CBP） to activate CBP-dependent transcription.In addition,TDG also interacts with the retinoic acid receptor α （RARα）,resulting in the activation of RARα target genes.Here we provide evidence for the existence of a functional ternary complex containing TDG,CBP and activated RARα.Using global transcriptome profiling,we uncover a coupling of de novo methylation-sensitive and RA-dependent transcription,which coincides with a significant subset of CBP target genes.The introduction of a point mutation in TDG,which neither affects overall protein structure nor BER activity,leads to a significant loss in ternary complex stability,resulting in the deregulation of RA targets involved in cellular networks associated with DNA replication,recombination and repair.We thus demonstrate for the first time a direct coupling of TDG＇s epigenomic and transcription regulatory function through ternary complexes with CBP and RARα.展开更多
文摘目的探讨视黄酸受体α(retinoic acid receptorα,RARα)信号变化通过调控视皮质轴突蛋白1(neurexin 1,NRXN1)参与维生素A缺乏(vitamin A deficiency,VAD)大鼠孤独症样行为的机制。方法构建孕期开始的维生素A正常(vitamin A normal,VAN)和VAD母鼠模型,并在生后早期对部分VAD母鼠和仔鼠给予维生素A补充(vitamin A supplement,VAS)。各组仔鼠(n=20)于6周龄进行行为学检测,利用三箱和旷场实验检测各组仔鼠社交行为和重复刻板行为;采用高效液相色谱法检测各组仔鼠血清视黄醇水平;采用电生理实验检测各组仔鼠视皮质的长时程增强(long-term potentiation,LTP)水平;采用实时荧光定量PCR法和Western blot法检测RARα、NRXN1和N-甲基-D-天冬氨酸受体1(N-methyl-D-aspartate receptor subunit 1,NMDAR1)的表达水平;采用染色质免疫共沉淀技术检测RARα转录因子在NRXN1基因启动子区的富集量。结果VAD组仔鼠出现社会交往障碍、重复刻板等孤独症样行为表现,生后开始的VAS可改善仔鼠大部分行为缺陷。VAD组仔鼠血清视黄醇水平明显低于VAN组和VAS组(P<0.05)。VAD组仔鼠视皮质NMDAR1、RARα和NRXN1的mRNA和蛋白表达水平及LTP水平均较VAN组和VAS组显著降低(P<0.05)。VAD组仔鼠视皮质中RARα转录因子在NRXN1基因启动子区的富集量较VAN组和VAS组显著下降(P<0.05)。结论RARα通过调控NRXN1影响VAD大鼠视皮质突触可塑性,从而参与VAD大鼠孤独症样行为的形成。[中国当代儿科杂志,2022,24(8):928-935]
基金funded by the Centre National de la Recherche Scientifique(CNRS)and the Genopole Evry
文摘The thymine DNA glycosylase （TDG） is a multifunctional enzyme,which is essential for embryonic development.It mediates the base excision repair （BER） of G：T and G：U DNA mismatches arising from the deamination of 5-methyl cytosine （5-MeC） and cytosine,respectively.Recent studies have pointed at a role of TDG during the active demethylation of 5-MeC within CpG islands.TDG interacts with the histone acetylase CREB-binding protein （CBP） to activate CBP-dependent transcription.In addition,TDG also interacts with the retinoic acid receptor α （RARα）,resulting in the activation of RARα target genes.Here we provide evidence for the existence of a functional ternary complex containing TDG,CBP and activated RARα.Using global transcriptome profiling,we uncover a coupling of de novo methylation-sensitive and RA-dependent transcription,which coincides with a significant subset of CBP target genes.The introduction of a point mutation in TDG,which neither affects overall protein structure nor BER activity,leads to a significant loss in ternary complex stability,resulting in the deregulation of RA targets involved in cellular networks associated with DNA replication,recombination and repair.We thus demonstrate for the first time a direct coupling of TDG＇s epigenomic and transcription regulatory function through ternary complexes with CBP and RARα.
