Activation of nuclear factor erythroid 2-related factor 2(Nrf2)by Kelch-like ECH-associated protein 1(Keap1)alkylation plays a central role in anti-inflammatory therapy.However,activators of Nrf2 through alkylation of...Activation of nuclear factor erythroid 2-related factor 2(Nrf2)by Kelch-like ECH-associated protein 1(Keap1)alkylation plays a central role in anti-inflammatory therapy.However,activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified.Deoxynyboquinone(DNQ)is a natural small molecule discovered from marine actinomycetes.The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1.DNQ exhibited significant anti-inflammatory properties both in vitro and in vivo.The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be theα,β-unsaturated amides moieties by a chemical reaction between DNQ and N-acetylcysteine.DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway.Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation.The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry.DNQ triggered the ubiquitination and subsequent degradation of Keap1 by alkylation of the cysteine residue 489(Cys489)on Keap1-Kelch domain,ultimately enabling the activation of Nrf2.Our findings revealed that DNQ exhibited potent anti-inflammatory capacity throughα,β-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain,suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies.展开更多
A major impedance to neuronal regeneration after peripheral nerve injury (PNI) is the activation of various programmed cell death mechanisms in the dorsal root ganglion. Ferroptosis is a form of programmed cell death ...A major impedance to neuronal regeneration after peripheral nerve injury (PNI) is the activation of various programmed cell death mechanisms in the dorsal root ganglion. Ferroptosis is a form of programmed cell death distinguished by imbalance in iron and thiol metabolism, leading to lethal lipid peroxidation. However, the molecular mechanisms of ferroptosis in the context of PNI and nerve regeneration remain unclear. Ferroportin (Fpn), the only known mammalian nonheme iron export protein, plays a pivotal part in inhibiting ferroptosis by maintaining intracellular iron homeostasis. Here, we explored in vitro and in vivo the involvement of Fpn in neuronal ferroptosis. We first delineated that reactive oxygen species at the injury site induces neuronal ferroptosis by increasing intracellular iron via accelerated UBA52-driven ubiquitination and degradation of Fpn, and stimulation of lipid peroxidation. Early administration of the potent arterial vasodilator, hydralazine (HYD), decreases the ubiquitination of Fpn after PNI by binding to UBA52, leading to suppression of neuronal cell death and significant acceleration of axon regeneration and motor function recovery. HYD targeting of ferroptosis is a promising strategy for clinical management of PNI.展开更多
DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-bu...DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-butylphthalide action by various means.We used hydrogen peroxide to induce injury to PC12cells and RAW264.7 cells to mimic neuronal oxidative stress injury in stroke in vitro and examined the effects of DI-3-n-butylphthalide.We found that DI-3-nbutylphthalide pretreatment markedly inhibited the reduction in viability and reactive oxygen species production in PC12 cells caused by hydrogen peroxide and inhibited cell apoptosis.Furthermore,DI-3-n-butylphthalide pretreatment inhibited the expression of the pro-apoptotic genes Bax and Bnip3.DI-3-nbutylphthalide also promoted ubiquitination and degradation of hypoxia inducible factor 1α,the key transcription factor that regulates Bax and Bnip3 genes.These findings suggest that DI-3-n-butylphthalide exhibits a neuroprotective effect on stroke by promoting hypoxia inducible factor-1α ubiquitination and degradation and inhibiting cell apoptosis.展开更多
Background:Cholangiocarcinoma(CCA)represents the epithelial cell cancer with high aggressiveness whose five-year survival rate is poor with standard treatment.Calcyclin-binding protein(CACYBP)shows aberrant expression...Background:Cholangiocarcinoma(CCA)represents the epithelial cell cancer with high aggressiveness whose five-year survival rate is poor with standard treatment.Calcyclin-binding protein(CACYBP)shows aberrant expression within several malignant tumors,but the role of CACYBP in CCA remains unknown.Methods:Immunohistochemical(IHC)analysis was used to identify CACYBP overexpression in clinical samples of CCA patients.Moreover,its correlation with clinical outcome was revealed.Furthermore,CACYBP’s effect on CCA cell growth and invasion was investigated in vitro and in vivo using loss-of-function experiments.Results:CACYBP showed up-regulation in CCA,which predicts the dismal prognostic outcome.CACYBP had an important effect on in-vitro and in-vivo cancer cell proliferation and migration.Additionally,knockdown of CACYBP weakened protein stability by promoting ubiquitination of MCM2.Accordingly,MCM2 up-regulation partly reversed CACYBP deficiency’s inhibition against cancer cell viability and invasion.Thus,MCM2 might drive CCA development by Wnt/β-catenin pathway.Conclusions:CACYBP exerted a tumor-promoting role in CCA by suppressing ubiquitination of MCM2 and activating Wnt/β-catenin pathway,hence revealing that it may be the possible therapeutic target for CCA treatment.展开更多
为探究一种包含泛素调节性X结构域的蛋白(ubiquitin regulatory X domain-containing protein,UBXN1)在大黄鱼抗盾纤毛虫感染中的作用,以及可能涉及的免疫信号通路。本实验克隆鉴定了大黄鱼UBXN1基因,并利用在线软件对其序列特征进行生...为探究一种包含泛素调节性X结构域的蛋白(ubiquitin regulatory X domain-containing protein,UBXN1)在大黄鱼抗盾纤毛虫感染中的作用,以及可能涉及的免疫信号通路。本实验克隆鉴定了大黄鱼UBXN1基因,并利用在线软件对其序列特征进行生物信息学分析;采用实时荧光定量PCR(qRT-PCR)检测UBXN1在健康大黄鱼各组织中的表达,及盾纤毛虫感染后的诱导表达变化;并进行了UBXN1的亚细胞定位;转录组测序分析了UBXN1过表达前后的差异表达基因。结果显示,UBXN1基因cDNA全长为915 bp,编码304个氨基酸。蛋白多重序列比对和结构预测表明UBXN1是一个进化保守的蛋白,包含UBA和UBX结构域。qRT-PCR分析表明UBXN1在所检测的11种组织中均有表达,脑中表达量最高,其次是肝脏、心脏和肾脏,在肌肉中表达量最低;盾纤毛虫感染大黄鱼后,UBXN1在脾脏、脑、肝脏和肾脏中表达量早期显著升高,后期逐步恢复至正常水平。亚细胞定位分析表明,UBXN1在大黄鱼肾脏细胞质和细胞核中均有表达。在293T细胞过表达UBXN1,转录组差异表达分析筛选到12个上调基因,4个下调基因,其中RPL41/RPL39/XIST/RNA45SN4表达量显著增加,而ATP8/ND4L表达量显著减少。研究表明UBXN1在大黄鱼抗寄生虫免疫应答中发挥重要作用。本实验为进一步研究UBXN1的免疫信号通路奠定基础。展开更多
目的研究非肌层浸润膀胱癌(non-muscle invasive bladder cancer,NMIBC)癌组织中结构域蛋白去泛素化酶5(domain protein ubiquitin 5,OTUD5)、环指蛋白186(ring finger protein 186,RNF186)表达与临床病理特征的关系及预后价值研究。方...目的研究非肌层浸润膀胱癌(non-muscle invasive bladder cancer,NMIBC)癌组织中结构域蛋白去泛素化酶5(domain protein ubiquitin 5,OTUD5)、环指蛋白186(ring finger protein 186,RNF186)表达与临床病理特征的关系及预后价值研究。方法收集2019年1月~2020年1月唐山市中医院收治的106例NMIBC患者。免疫组织化学检测NMIBC癌组织及癌旁组织OTUD5,RNF186表达。比较不同临床病理特征NMIBC癌组织OTUD5,RNF186表达差异。Kaplan-Meier曲线分析(Log-Rank检验)OTUD5,RNF186表达对NMIBC无进展生存预后的影响。COX回归模型分析影响NMIBC患者无进展生存预后的因素。结果NMIBC癌组织中OTUD5(62.26%),RNF186(66.04%)的阳性率高于癌旁组织(11.32%,8.49%),差异具有统计学意义(χ^(2)=59.146,75.079,均P<0.05)。NMIBC癌组织中OTUD5与RNF186表达呈显著正相关(r=0.659,P<0.05)。T 1期、高级别尿路上皮癌NMIBC癌组织中OTUD5(72.97%,84.21%),RNF186(77.03,86.84%)阳性率高于Ta/Tis期(37.50%,50.00%)、低级别尿路上皮癌(40.63%,54.41%),差异具有统计学意义(χ^(2)=11.964,13.199;12.143,11.431,均P<0.05)。OTUD5阳性组(40.91%)、RNF186阳性组(45.71%)三年累积无进展生存率低于OTUD5阴性组(90.00%)、RNF186阴性组(86.11%)患者(Log-Ranktestχ^(2)=24.710,14.586,均P<0.05)。OTUD5阳性(OR=1.446,95%CI:1.086~1.925)、RNF186阳性(OR=1.579,95%CI:1.132~2.024)、肿瘤TNM分期T1期(OR=1.582,95%CI:1.219~2.054)、病理分级高级别(OR=1.570,95%CI:1.188~2.074)是影响NMIBC患者无进展生存的独立危险因素(均P<0.001)。结论NMIBC患者癌组织OTUD5,RNF186表达升高,与肿瘤TNM分期、病理分级有关,是影响NMIBC患者预后的独立危险因素。展开更多
基金the Science and Technology Development Fund,Macao SAR(Grant Nos.:No.0159/2020/A3,No.0058/2020/AMJ,No.0096/2019/A2 and SKL-QRCM(UM)-2023-2025)the Research Committee of the University of Macao(Grant No.:MYRG2022-00189-ICMS)+2 种基金the Guangdong Provincial Special Fund for Marine Economic Development Project(Project No.:GDNRC[2021]48)National Natural Science Foundation of China(Grant No.:82260801)K.C.Wong Education Foundation(Grant No.:GJTD-2020-12).
文摘Activation of nuclear factor erythroid 2-related factor 2(Nrf2)by Kelch-like ECH-associated protein 1(Keap1)alkylation plays a central role in anti-inflammatory therapy.However,activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified.Deoxynyboquinone(DNQ)is a natural small molecule discovered from marine actinomycetes.The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1.DNQ exhibited significant anti-inflammatory properties both in vitro and in vivo.The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be theα,β-unsaturated amides moieties by a chemical reaction between DNQ and N-acetylcysteine.DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway.Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation.The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry.DNQ triggered the ubiquitination and subsequent degradation of Keap1 by alkylation of the cysteine residue 489(Cys489)on Keap1-Kelch domain,ultimately enabling the activation of Nrf2.Our findings revealed that DNQ exhibited potent anti-inflammatory capacity throughα,β-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain,suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.:82122043,81972052,81902213,82201537,and 81730065)the China Postdoctoral Science Foundation(Grant Nos.:2021M693946 and 2019M653967).
文摘A major impedance to neuronal regeneration after peripheral nerve injury (PNI) is the activation of various programmed cell death mechanisms in the dorsal root ganglion. Ferroptosis is a form of programmed cell death distinguished by imbalance in iron and thiol metabolism, leading to lethal lipid peroxidation. However, the molecular mechanisms of ferroptosis in the context of PNI and nerve regeneration remain unclear. Ferroportin (Fpn), the only known mammalian nonheme iron export protein, plays a pivotal part in inhibiting ferroptosis by maintaining intracellular iron homeostasis. Here, we explored in vitro and in vivo the involvement of Fpn in neuronal ferroptosis. We first delineated that reactive oxygen species at the injury site induces neuronal ferroptosis by increasing intracellular iron via accelerated UBA52-driven ubiquitination and degradation of Fpn, and stimulation of lipid peroxidation. Early administration of the potent arterial vasodilator, hydralazine (HYD), decreases the ubiquitination of Fpn after PNI by binding to UBA52, leading to suppression of neuronal cell death and significant acceleration of axon regeneration and motor function recovery. HYD targeting of ferroptosis is a promising strategy for clinical management of PNI.
文摘DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-butylphthalide action by various means.We used hydrogen peroxide to induce injury to PC12cells and RAW264.7 cells to mimic neuronal oxidative stress injury in stroke in vitro and examined the effects of DI-3-n-butylphthalide.We found that DI-3-nbutylphthalide pretreatment markedly inhibited the reduction in viability and reactive oxygen species production in PC12 cells caused by hydrogen peroxide and inhibited cell apoptosis.Furthermore,DI-3-n-butylphthalide pretreatment inhibited the expression of the pro-apoptotic genes Bax and Bnip3.DI-3-nbutylphthalide also promoted ubiquitination and degradation of hypoxia inducible factor 1α,the key transcription factor that regulates Bax and Bnip3 genes.These findings suggest that DI-3-n-butylphthalide exhibits a neuroprotective effect on stroke by promoting hypoxia inducible factor-1α ubiquitination and degradation and inhibiting cell apoptosis.
基金funded by Shenzhen Key Medical Discipline Construction Fund(No.SZXK015)Guangdong Provincial Key Clinical Specialty Construction Project,National Key Clinical Specialty Construction Project and Guangdong Medical Science and Technology Research Fund(No.A2021230).
文摘Background:Cholangiocarcinoma(CCA)represents the epithelial cell cancer with high aggressiveness whose five-year survival rate is poor with standard treatment.Calcyclin-binding protein(CACYBP)shows aberrant expression within several malignant tumors,but the role of CACYBP in CCA remains unknown.Methods:Immunohistochemical(IHC)analysis was used to identify CACYBP overexpression in clinical samples of CCA patients.Moreover,its correlation with clinical outcome was revealed.Furthermore,CACYBP’s effect on CCA cell growth and invasion was investigated in vitro and in vivo using loss-of-function experiments.Results:CACYBP showed up-regulation in CCA,which predicts the dismal prognostic outcome.CACYBP had an important effect on in-vitro and in-vivo cancer cell proliferation and migration.Additionally,knockdown of CACYBP weakened protein stability by promoting ubiquitination of MCM2.Accordingly,MCM2 up-regulation partly reversed CACYBP deficiency’s inhibition against cancer cell viability and invasion.Thus,MCM2 might drive CCA development by Wnt/β-catenin pathway.Conclusions:CACYBP exerted a tumor-promoting role in CCA by suppressing ubiquitination of MCM2 and activating Wnt/β-catenin pathway,hence revealing that it may be the possible therapeutic target for CCA treatment.
