Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ...Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ischemic-reperfusion injury(CIRI)remains unclear.This study aimed to determine whether celastrol could reduce oxidative damage during CIRI and to elucidate the underlying mechanisms.Here,we found that celastrol attenuated oxidative injury in CIRI by upregulating nuclear factor E2-related factor 2(Nrf2).Using alkynyl-tagged celastrol and liquid chromatography-tandem mass spectrometry,we showed that celastrol directly bound to neuronally expressed developmentally downregulated 4(Nedd4)and then released Nrf2 from Nedd4 in astrocytes.Nedd4 promoted the degradation of Nrf2 through K48-linked ubiquitination and thus contributed to astrocytic reactive oxygen species production in CIRI,which was significantly blocked by celastrol.Furthermore,by inhibiting oxidative stress and astrocyte activation,celastrol effectively rescued neurons from axon damage and apoptosis.Our study uncovered Nedd4 as a direct target of celastrol,and that celastrol exerts an antioxidative effect on astrocytes by inhibiting the interaction between Nedd4 and Nrf2 and reducing Nrf2 degradation in CIRI.展开更多
文摘目的探讨神经前体细胞表达发育调控样蛋白(Nedd4L)通过泛素化降解癌蛋白神经生长因子酪氨酸激酶受体(Trk A)抑制老年前列腺癌的分子作用机制。方法收集手术切除的43例老年前列腺癌组织及对应癌旁组织标本。免疫组化染色检测Nedd4L及Trk A的表达,在人前列腺癌LNCa P细胞中转染Nedd4L特异性si RNA后,采用q RT-PCR及Western印迹检测LNCa P细胞内Trk A m RNA及蛋白的表达变化。结果Nedd4L蛋白在老年前列腺癌组织中表达明显降低,而Trk A表达显著升高(P<0.05);二者呈显著负相关(P<0.05),Nedd4L的表达降低与Trk A表达升高均与肿瘤淋巴结转移、高TNM分期显著相关(P<0.05);在体外,下调Nedd4L表达后可显著升高Trk A蛋白的表达水平(P<0.05),而对Trk A m RNA表达无明显影响(P>0.05)。结论 Nedd4L及Trk A在老年前列腺癌组织中异常表达,Nedd4L可能通过泛素化降解癌蛋白Trk A实现其抗肿瘤作用。
基金the National Natural Science Foundation of China(Grant No.:81973305)the Science and Technology Planning Project of Guangzhou,China(Grant No.:201904010487)+1 种基金the Natural Science Foundation of Guangdong Province,China(Grant No.:2021A1515010897)the Discipline Construction Fund of Central People’s Hospital of Zhanjiang(Grant Nos.:2020A01 and 2020A02).
文摘Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ischemic-reperfusion injury(CIRI)remains unclear.This study aimed to determine whether celastrol could reduce oxidative damage during CIRI and to elucidate the underlying mechanisms.Here,we found that celastrol attenuated oxidative injury in CIRI by upregulating nuclear factor E2-related factor 2(Nrf2).Using alkynyl-tagged celastrol and liquid chromatography-tandem mass spectrometry,we showed that celastrol directly bound to neuronally expressed developmentally downregulated 4(Nedd4)and then released Nrf2 from Nedd4 in astrocytes.Nedd4 promoted the degradation of Nrf2 through K48-linked ubiquitination and thus contributed to astrocytic reactive oxygen species production in CIRI,which was significantly blocked by celastrol.Furthermore,by inhibiting oxidative stress and astrocyte activation,celastrol effectively rescued neurons from axon damage and apoptosis.Our study uncovered Nedd4 as a direct target of celastrol,and that celastrol exerts an antioxidative effect on astrocytes by inhibiting the interaction between Nedd4 and Nrf2 and reducing Nrf2 degradation in CIRI.
