Background:Melatonin,a natural hormone secreted by the pineal gland,has been reported to exhibit antitumor properties through diverse mechanisms of action.However,the oncostatic function of melatonin on esophageal squ...Background:Melatonin,a natural hormone secreted by the pineal gland,has been reported to exhibit antitumor properties through diverse mechanisms of action.However,the oncostatic function of melatonin on esophageal squamous cell carcinoma(ESCC) remains elusive.This study was conducted to investigate the potential effect and underlying molecular mechanism of melatonin as single anticancer agent against ESCC cells.Methods:ESCC cell lines treated with or without melatonin were used in this study.In vitro colony formation and 5-Ethynyl-2’-deoxyuridine(EdU) incorporation assays,and nude mice tumor xenograft model were used to confirm the proliferative capacities of ESCC cells.RNA-seq,qPCR,Western blotting,recombinant lentivirus-mediated target gene overexpression or knockdown,plasmids transfection and co-IP were applied to investigate the underlying molecular mechanism by which melatonin inhibited ESCC cell growth.IHC staining on ESCC tissue microarray and further survival analyses were performed to explore the relationship between target genes’ expression and prognosis of ESCC.Results:Melatonin treatment dose-dependently inhibited the proliferative ability and the expression of histone deacetylase 7(HDAC7),c-Myc and ubiquitin-specific peptidase 10(USP10) in ESCC cells(P<0.05).The expressions of HDAC7,c-Myc and USP10 in tumors were significantly higher than the paired normal tissues from 148 ESCC patients(P<0.001).Then,the Kaplan-Meier survival analysis suggested that ESCC patients with high HDAC7,c-Myc or USP10levels predicted worse overall survival(log-rank P<0.001).Co-IP and Western blotting further revealed that HDAC7physically deacetylated and activated β-catenin thus promoting downstream target c-Myc gene transcription.Notably,our mechanistic study validated that HDAC7/β-catenin/c-Myc could form the positive feedback loop to enhance ESCC cell growth,and USP10 could deubiquitinate and stabilize HDAC7 protein in the ESCC cells.Additionally,we verified that inhibition of the HDAC7/β-catenin/c-Myc axis and USP10/HDAC7 pathway mediated the anti-proliferative action of melatonin on ESCC cells.Conclusions:Our findings elucidate that melatonin mitigates the HDAC7/β-catenin/c-Myc positive feedback loop and inhibits the USP10-maintained HDAC7 protein stability thus suppressing ESCC cell growth,and provides the reference for identifying biomarkers and therapeutic targets for ESCC.展开更多
Activation-induced cytidine deaminase(AID)initiates class-switch recombination and somatic hypermutation(SHM)in antibody genes.Protein expression and activity are tightly controlled by various mechanisms.However,it re...Activation-induced cytidine deaminase(AID)initiates class-switch recombination and somatic hypermutation(SHM)in antibody genes.Protein expression and activity are tightly controlled by various mechanisms.However,it remains unknown whether a signal from the extracellular environment directly affects the AID activity in the nucleus where it works.Here,we demonstrated that a deubiquitinase USP10,which specifically stabilizes nuclear AID protein,can translocate into the nucleus after AKT-mediated phosphorylation at its T674 within the NLS domain.Interestingly,the signals from BCR and TLR1/2 synergistically promoted this phosphorylation.The deficiency of USP10 in B cells significantly decreased AID protein levels,subsequently reducing neutralizing antibody production after immunization with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)or human immunodeficiency virus type 1(HIV-1)nanoparticle vaccines.Collectively,we demonstrated that USP10 functions as an integrator for both BCR and TLR signals and directly regulates nuclear AID activity.Its manipulation could be used for the development of vaccines and adjuvants.展开更多
The adaptor molecule MAVS forms prion-like aggregates to govern the RIG-I-like receptor(RLR)signaling cascade.Lys63(K63)-linked polyubiquitination is critical for MAVS aggregation,yet the underlying mechanism and the ...The adaptor molecule MAVS forms prion-like aggregates to govern the RIG-I-like receptor(RLR)signaling cascade.Lys63(K63)-linked polyubiquitination is critical for MAVS aggregation,yet the underlying mechanism and the corresponding E3 ligases and deubiquitinating enzymes(DUBs)remain elusive.Here,we found that the K63-linked polyubiquitin chains loaded on MAVS can be directly recognized by RIG-I to initiate RIG-I-mediated MAVS aggregation with the prerequisite of the CARDRIG-I-CARDMAVS interaction.Interestingly,many K63-linked polyubiquitin chains attach to MAVS via an unanchored linkage.We identified Ube2N as a major ubiquitin-conjugating enzyme for MAVS and revealed that Ube2N cooperates with the E3 ligase Riplet and TRIM31 to promote the unanchored K63-linked polyubiquitination of MAVS.In addition,we identified USP10 as a direct DUB that removes unanchored K63-linked polyubiquitin chains from MAVS.Consistently,USP10 attenuates RIG-I-mediated MAVS aggregation and the production of type I interferon.Mice with a deficiency in USP10 show more potent resistance to RNA virus infection.Our work proposes a previously unknown mechanism for the activation of the RLR signaling cascade triggered by MAVS-attached unanchored K63-linked polyubiquitin chains and establishes the DUB USP10 and the E2:E3 pair Ube2N-Riplet/TRIM31 as a specific regulatory system for the unanchored K63-linked ubiquitination and aggregation of MAVS upon viral infection.展开更多
基金supported by the National Natural Science Foundation of China (82103508, 81871866, 82173252, 81672996)the Natural Science Foundation of Shaanxi Province (2022JQ?862)。
文摘Background:Melatonin,a natural hormone secreted by the pineal gland,has been reported to exhibit antitumor properties through diverse mechanisms of action.However,the oncostatic function of melatonin on esophageal squamous cell carcinoma(ESCC) remains elusive.This study was conducted to investigate the potential effect and underlying molecular mechanism of melatonin as single anticancer agent against ESCC cells.Methods:ESCC cell lines treated with or without melatonin were used in this study.In vitro colony formation and 5-Ethynyl-2’-deoxyuridine(EdU) incorporation assays,and nude mice tumor xenograft model were used to confirm the proliferative capacities of ESCC cells.RNA-seq,qPCR,Western blotting,recombinant lentivirus-mediated target gene overexpression or knockdown,plasmids transfection and co-IP were applied to investigate the underlying molecular mechanism by which melatonin inhibited ESCC cell growth.IHC staining on ESCC tissue microarray and further survival analyses were performed to explore the relationship between target genes’ expression and prognosis of ESCC.Results:Melatonin treatment dose-dependently inhibited the proliferative ability and the expression of histone deacetylase 7(HDAC7),c-Myc and ubiquitin-specific peptidase 10(USP10) in ESCC cells(P<0.05).The expressions of HDAC7,c-Myc and USP10 in tumors were significantly higher than the paired normal tissues from 148 ESCC patients(P<0.001).Then,the Kaplan-Meier survival analysis suggested that ESCC patients with high HDAC7,c-Myc or USP10levels predicted worse overall survival(log-rank P<0.001).Co-IP and Western blotting further revealed that HDAC7physically deacetylated and activated β-catenin thus promoting downstream target c-Myc gene transcription.Notably,our mechanistic study validated that HDAC7/β-catenin/c-Myc could form the positive feedback loop to enhance ESCC cell growth,and USP10 could deubiquitinate and stabilize HDAC7 protein in the ESCC cells.Additionally,we verified that inhibition of the HDAC7/β-catenin/c-Myc axis and USP10/HDAC7 pathway mediated the anti-proliferative action of melatonin on ESCC cells.Conclusions:Our findings elucidate that melatonin mitigates the HDAC7/β-catenin/c-Myc positive feedback loop and inhibits the USP10-maintained HDAC7 protein stability thus suppressing ESCC cell growth,and provides the reference for identifying biomarkers and therapeutic targets for ESCC.
基金This work was supported by the National Special Research Program of China for Important Infectious Diseases(2017ZX10202102 and 2018ZX10302103)the Special 2019-nCoV Project of the National Key Research and Development Program of China(2020YFC0841400)the Special 2019-nCoV Program of the Natural Science Foundation of China(NSFC)(82041002),the Emergency Key Program of Guangzhou Laboratory(EKPG21-24),the Important Key Program of NSFC(81730060),and the Joint-Innovation Program in Healthcare for Special Scientific Research Projects of Guangzhou(201803040002)to Hui Zhang,the Postdoctoral Science Foundation of China(2019M663249,2020M683032)to Yuewen Luo and Jun Liu,the Guangdong Basic and Applied Basic Research Foundation(2020A1515110807)to Yuewen Luo and the Fundamental Research Funds for the Central Universities(20ykpy138)to Yuewen Luo.
文摘Activation-induced cytidine deaminase(AID)initiates class-switch recombination and somatic hypermutation(SHM)in antibody genes.Protein expression and activity are tightly controlled by various mechanisms.However,it remains unknown whether a signal from the extracellular environment directly affects the AID activity in the nucleus where it works.Here,we demonstrated that a deubiquitinase USP10,which specifically stabilizes nuclear AID protein,can translocate into the nucleus after AKT-mediated phosphorylation at its T674 within the NLS domain.Interestingly,the signals from BCR and TLR1/2 synergistically promoted this phosphorylation.The deficiency of USP10 in B cells significantly decreased AID protein levels,subsequently reducing neutralizing antibody production after immunization with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)or human immunodeficiency virus type 1(HIV-1)nanoparticle vaccines.Collectively,we demonstrated that USP10 functions as an integrator for both BCR and TLR signals and directly regulates nuclear AID activity.Its manipulation could be used for the development of vaccines and adjuvants.
基金supported by grants from the National Natural Science Foundation of China(31730026,81930039,32000633)National Key Research and Development Program(2021YFC2300603),Natural Science Foundation of Shandong Province(ZR2020QH136)China Postdoctoral Science Foundation(2020M682187),and Postdoctoral Innovation Project of Shandong Province(202002012).
文摘The adaptor molecule MAVS forms prion-like aggregates to govern the RIG-I-like receptor(RLR)signaling cascade.Lys63(K63)-linked polyubiquitination is critical for MAVS aggregation,yet the underlying mechanism and the corresponding E3 ligases and deubiquitinating enzymes(DUBs)remain elusive.Here,we found that the K63-linked polyubiquitin chains loaded on MAVS can be directly recognized by RIG-I to initiate RIG-I-mediated MAVS aggregation with the prerequisite of the CARDRIG-I-CARDMAVS interaction.Interestingly,many K63-linked polyubiquitin chains attach to MAVS via an unanchored linkage.We identified Ube2N as a major ubiquitin-conjugating enzyme for MAVS and revealed that Ube2N cooperates with the E3 ligase Riplet and TRIM31 to promote the unanchored K63-linked polyubiquitination of MAVS.In addition,we identified USP10 as a direct DUB that removes unanchored K63-linked polyubiquitin chains from MAVS.Consistently,USP10 attenuates RIG-I-mediated MAVS aggregation and the production of type I interferon.Mice with a deficiency in USP10 show more potent resistance to RNA virus infection.Our work proposes a previously unknown mechanism for the activation of the RLR signaling cascade triggered by MAVS-attached unanchored K63-linked polyubiquitin chains and establishes the DUB USP10 and the E2:E3 pair Ube2N-Riplet/TRIM31 as a specific regulatory system for the unanchored K63-linked ubiquitination and aggregation of MAVS upon viral infection.
