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
Background:NOD-like receptor family CARD domain containing 3(NLRC3)plays an important role in both innate and adaptive immunity.This study was to explore the function and related mechanisms of NLRC3 in a hypoxia/reoxy...Background:NOD-like receptor family CARD domain containing 3(NLRC3)plays an important role in both innate and adaptive immunity.This study was to explore the function and related mechanisms of NLRC3 in a hypoxia/reoxygenation(H/R)-induced inflammatory response in RAW264.7 cells.Methods:Liver ischemia-reperfusion(I/R)model in mice and H/R model in RAW264.7 cells were constructed.Western blotting was used to determine the protein expression level of NLRC3 in liver tissue and NLRC3,TRAF6,p–p65,p65,IκB–α,and the K63-linked ubiquitination level of TRAF6 in cells.The immunofluorescence assay was performed to evaluate the nuclear level of the NF–κB(p65).ELISA was conducted to measure the content of IL–1βin serum and cell supernatant.The interaction between NLRC3 and TRAF6 in cells was analyzed by the Co-IP assay.Results:The NLRC3 protein level in liver tissue was decreased with the prolongation of reperfusion time(P<0.05).The expression of NLRC3 and IκB–αprotein in RAW264.7 was decreased gradually,while the expression of p–p65 and TRAF6 proteins and K63-linked ubiquitination of TRAF6 were increased gradually with the prolongation of reoxgenation time(P<0.05).The Co-IP assay revealed that NLRC3 and TRAF6 can bind to each other directly.However,NLRC3 had no effect on the expression of TRAF6 protein.The ubiquitination test results showed that the K63-linked ubiquitination level of TRAF6 in H/R+Lv–NLRC3 group was significantly lower than that in the H/R+negative control(NC)group(P<0.05).Moreover,the activation of NF–κB in H/R+Lv–NLRC3 group was inhibited compared with that in the H/R+NC group,and the level of the inflammatory factor IL–1βin the cell culture supernatant was also decreased accordingly(P<0.05).Conclusions:NLRC3 might alleviate H/R-induced inflammation in RAW264.7 cells by inhibiting K63-linked ubiquitination of TRAF6.展开更多
Lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma) is the most common extranodal B cell tumor and accounts for 8% of non-Hodgkin's lymphomas. Gastric MALT lymphoma is the best-studied example and is a pr...Lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma) is the most common extranodal B cell tumor and accounts for 8% of non-Hodgkin's lymphomas. Gastric MALT lymphoma is the best-studied example and is a prototypical neoplasm that occurs in the setting of chronic inflammation brought on by persistent infection or autoimmune disease. Cytogenetic abnormalities are commonly acquired during the course of disease and the most common is chromosomal translocation t(11;18)(q21;q21), which creates the API2-MALT1 fusion oncoprotein. t(11;18)-positive lymphomas can be clinically aggressive and have a higher rate of dissemination than t(11;18)-negative tumors. Many cancers, including MALT lymphomas, characteristically exhibit deregulated over-activation of cellular survival pathways, such as the nuclear factor-κB(NF-κB) pathway. Molecular characterization of API2-MALT1 has revealed it to be a potent activator of NF-κB, which is required for API2-MALT1-induced cellular transformation, however the mechanisms by which API2-MALT1 exerts these effects are only recently becoming apparent. The API2 moiety of the fusion binds tumor necrosis factor(TNF) receptor associated factor(TRAF) 2 and receptor interacting protein 1(RIP1), two proteins essential for TNF receptor induced NF-κB activation. By effectively mimicking ligand-bound TNF receptor, API2-MALT1 promotes TRAF2-dependent ubiquitination of RIP1, which then acts as a scaffold for nucleating and activating the canonical NF-κB machinery. Activation occurs, in part, through MALT1 moiety-dependent recruitment of TRAF6, which can directly modify NF-κB essential modulator, the principal downstream regulator of NF-κB. While theintrinsic MALT1 protease catalytic activity is dispensable for this canonical NF-κB signaling, it is critical for noncanonical NF-κB activation. In this regard, API2-MALT1 recognizes NF-κB inducing kinase(NIK), the essential upstream regulator of non-canonical NF-κB, and cleaves it to generate a stable, constitutively active fragment. Thus, API2-MALT1 harnesses multiple unique pathways to achieve deregulated NF-κB activation. Emerging data from our group and others have also detailed additional gain-of-function activities of API2-MALT1 that extend beyond NF-κB activation. Specifically, API2-MALT1 recruits and subverts multiple other signaling factors, including LIM domain and actin-binding protein 1(LIMA1) and Smac/DIABLO. Like NIK, LIMA1 represents a unique substrate for API2-MALT1 protease activity, but unlike NIK, its cleavage sets in motion a major NF-κB-independent pathway for promoting oncogenesis. In this review, we highlight the most recent results characterizing these unique and diverse gain-of-function activities of API2-MALT1 and how they contribute to lymphomagenesis.展开更多
As an important primary metabolite,malate plays a key role in regulating osmotic pressure,pH homeostasis,stress tolerance,and fruit quality of apple.The R2R3-MYB transcription factor(TF)MdMYB73 was identified as a pro...As an important primary metabolite,malate plays a key role in regulating osmotic pressure,pH homeostasis,stress tolerance,and fruit quality of apple.The R2R3-MYB transcription factor(TF)MdMYB73 was identified as a protein that plays a critical role in determining malate accumulation and vacuolar acidification by directly regulating the transcription of aluminum-activated malate transporter 9(MdALMT9),vacuolar ATPase subunit A(MdVHA-A),and vacuolar pyrophosphatase 1(MdVHP1)in apple.In addition,the bHLH TF MdCIbHLH1 interacts with MdMYB73 and enhances the transcriptional activity of MdMYB73.Our previous studies demonstrated that the BTB-BACK-TAZ domain protein MdBT2 can degrade MdCIbHLH1 to influence malate accumulation and vacuolar acidification.However,the potential upstream regulators of MdMYB73 are currently unknown.In this study,we found that MdBT2 directly interacts with and degrades MdMYB73 through the ubiquitin/26S proteasome pathway to regulate malate accumulation and vacuolar acidification.A series of functional assays with apple calli and fruit showed that MdBT2 controls malate accumulation and vacuolar acidification in an MdMYB73-dependent manner.Overall,our findings shed light on the mechanism by which the BTB-BACK-TAZ domain protein MdBT2 regulates malate accumulation and vacuolar acidification by targeting MdMYB73 and MdCIbHLH1 for ubiquitination in apple.This information may help guide traditional breeding programs and fruit tree molecular breeding,and lead to improvements in fruit quality and stress tolerance.展开更多
Krüppel-like factor(KLF) family proteins are transcription factors that regulate numerous cellular functions, such as cell proliferation, differentiation, and cell death. Posttranslational modification of KLF pro...Krüppel-like factor(KLF) family proteins are transcription factors that regulate numerous cellular functions, such as cell proliferation, differentiation, and cell death. Posttranslational modification of KLF proteins is important for their transcriptional activities and biological functions. One KLF family member with important roles in cell proliferation and tumorigenesis is KLF5. The function of KLF5 is tightly controlled by post-translational modifications, including SUMOylation, phosphorylation, and ubiquitination. Recent studies from our lab and others' have demonstrated that the tumor suppressor FBW7 is an essential E3 ubiquitin ligase that targets KLF5 for ubiquitination and degradation. KLF5 contains functional Cdc4 phospho-degrons(CPDs), which are required for its interaction with FBW7. Mutation of CPDs in KLF5 blocks the ubiquitination and degradation of KLF5 by FBW7. The protein kinase Glycogen synthase kinase 3β is involved in the phosphorylation of KLF5 CPDs. In both cancer cell lines and mousemodels, it has been shown that FBW7 regulates the expression of KLF5 target genes through the modulation of KLF5 stability. In this review, we summarize the current progress on delineating FBW7-mediated KLF5 ubiquitination and degradation.展开更多
Background:Liver cancer is a malignancy with high morbidity and mortality rates.Serpin family E member 2(SERPINE2)has been reported to play a key role in the metastasis of many tumors.In this study,we aimed to investi...Background:Liver cancer is a malignancy with high morbidity and mortality rates.Serpin family E member 2(SERPINE2)has been reported to play a key role in the metastasis of many tumors.In this study,we aimed to investigate the potential mechanism of SERPINE2 in liver cancer metastasis.Methods:The Cancer Genome Atlas database(TCGA),including DNA methy-lation and transcriptome sequencing data,was utilized to identify the crucial oncogene associated with DNA methylation and cancer progression in liver can-cer.Data from the TCGA and RNA sequencing for 94 pairs of liver cancer tissues were used to explore the correlation between SERPINE2 expression and clin-ical parameters of patients.DNA methylation sequencing was used to detect the DNA methylation levels in liver cancer tissues and cells.RNA sequencing,cytokine assays,immunoprecipitation(IP)and mass spectrometry(MS)assays,protein stability assays,and ubiquitination assays were performed to explore the regulatory mechanism of SERPINE2 in liver cancer metastasis.Patient-derived xenografts and tumor organoid models were established to determine the role of SERPINE2 in the treatment of liver cancer using sorafenib.Results:Based on the public database screening,SERPINE2 was identified as a tumor promoter regulated by DNA methylation.SERPINE2 expression was significantly higher in liver cancer tissues and was associated with the dismal prognosis in patients with liver cancer.SERPINE2 promoted liver cancer metas-tasis by enhancing cell pseudopodia formation,cell adhesion,cancer-associated fibroblast activation,extracellular matrix remodeling,and angiogenesis.IP/MS assays confirmed that SERPINE2 activated epidermal growth factor receptor(EGFR)and its downstream signaling pathways by interacting with EGFR.Mechanistically,SERPINE2 inhibited EGFR ubiquitination and maintained its protein stability by competing with the E3 ubiquitin ligase,c-Cbl.Additionally,EGFR was activated in liver cancer cells after sorafenib treatment,and SER-PINE2 knockdown-induced EGFR downregulation significantly enhanced the therapeutic efficacy of sorafenib against liver cancer.Furthermore,we found that SERPINE2 knockdown also had a sensitizing effect on lenvatinib treatment.Conclusions:SERPINE2 promoted liver cancer metastasis by preventing EGFR degradation via c-Cbl-mediated ubiquitination,suggesting that inhibition of the SERPINE2-EGFR axis may be a potential target for liver cancer treatment.展开更多
Tetrabromobisphenol A(TBBPA)and its derivatives widely exist in various environments and biota.Although the available data indicate that TBBPA exposure is highly associated with the increased incidence of endometrial ...Tetrabromobisphenol A(TBBPA)and its derivatives widely exist in various environments and biota.Although the available data indicate that TBBPA exposure is highly associated with the increased incidence of endometrial cancer(EC),the effects of TBBPA and its main derivatives on EC proliferation and the involved crucial mechanism remain unclear.The present study aimed to investigate the effects of TBBPA and its derivatives under environmental concentrations on the proliferation of EC,and the crucial mechanism on the progression of EC caused by bromine fame retardants exposure.In this research,TBBPA and two of the most common TBBPA derivatives including TBBPA bis(2-hydroxyethyl ether)(TBBPABHEE)and TBBPA bis(dibromopropyl ether)(TBBPA-BDBPE)were screened for their capacities in induced EC proliferation and explored the related mechanism by in vitro cell culture model and in vivo mice model.Under environmental concentrations,TBBPA promoted the proliferation of EC,the main derivatives of TBBPA(TBBPA-BHEE and TBBPA-BDBPE)did not present the similar facilitation effects.The ubiquitination degradation of p53 was crucial in TBBPA induced EC proliferation,which resulted in the increase of downstream cell cycle and decrease of apoptosis.The further molecular docking result suggested the high affinity between TBBPA and ubiquitinated proteasome.This finding revealed the effects of TBBPA and its derivatives on EC proliferation,thus providing novel insights into the underlying mechanisms of TBBPA-caused EC.展开更多
Chronic myelogenous leukemia(CML)is a malignancy from bone marrow myeloid stem cells mainly driven by the fusion gene BCR-ABL.In addition to BCR-ABL,other genes including RNF6 are also dysregulated in CML cells.1 RNF6...Chronic myelogenous leukemia(CML)is a malignancy from bone marrow myeloid stem cells mainly driven by the fusion gene BCR-ABL.In addition to BCR-ABL,other genes including RNF6 are also dysregulated in CML cells.1 RNF6,a ubiquitin ligase of the RING family,promotes various cancer cell proliferation,chemoresistance,and tumor growth in vivo by targeting various proteins for ubiquitination and degradation,including SHP1,TLE3,FOXA1,and MAD1.^(2) However,its specific mechanism in CML is not known.展开更多
As members of the immune checkpoint family, PD-1 and its ligand PD-L1 play critical roles in maintaining the balance between autoimmunity and tolerance. The interaction of PD-1/PD-L1 is also involved in tumor evasion ...As members of the immune checkpoint family, PD-1 and its ligand PD-L1 play critical roles in maintaining the balance between autoimmunity and tolerance. The interaction of PD-1/PD-L1 is also involved in tumor evasion inside the tumor microenvironment, caused by reduced T cell activation, proliferation, cytotoxic secretion, and survival. Previous research has shown that the expression level of PD-1/PD-L1 may be regulated by ubiquitin-mediated proteasome degradation, which is an important mode of post-translational modification (PTM). PD-1/PD-L1 ubiquitin modification research in tumor immunotherapy is the subject of the present review, which aims to assess the most recent developments in this area. We offer a short explanation of PD-1/PD-L1 as well as some basic background information on the UPS system and discuss many routes that target E3s and DUBs, respectively, in the regulation of PD-1/PD-L1 in tumor immunotherapy. In addition, we offer numerous innovative prospective research areas for the future, as well as novel immunotherapy concepts and ideas. Taken together, the information compiled herein should serve as a comprehensive repository of information about tumor immunotherapy that is currently available, and it should be useful in the design of future studies, as well as the development of potential targets and strategies for future tumor immunotherapy.展开更多
Background:Previous studies have revealed the critical role of transglutaminase 2(TGM2)as a potential therapeutic target in cancers,but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer(GC)are no...Background:Previous studies have revealed the critical role of transglutaminase 2(TGM2)as a potential therapeutic target in cancers,but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer(GC)are not fully understood.In this study,we examined the role and potential mechanism of TGM2 in GC.Methods:Western blotting,immunohistochemistry,CCK8,colony formation and transwell assays were used to measure TGM2 expression in the GC cells and tissues and to examine the in vitro role of TGM2 in GC.Xenograft and in vivo metastasis experiments were performed to examine the in vivo role of TGM2 in GC.Gene set enrichment analysis,quantitative PCR and western blotting were conducted to screen for potential TGM2 targets involved in GC.Gain/loss-offunction and rescue experiments were conducted to detect the biological roles of STAT1 in GC cells in the context of TGM2.Co-immunoprecipitation,mass spectrometry,quantitative PCR and western blotting were conducted to identify STAT1-interacting proteins and elucidate their regulatory mechanisms.Mutations in TGM2 and two molecules(ZM39923 and A23187)were used to identify the enzymatic activity of TGM2 involved in the malignant progression of GC and elucidate the underlying mechanism.Results:In this study,we demonstrated elevated TGM2 expression in the GC tissues,which closely related to pathological grade,and predicted poor survival in patients with GC.TGM2 overexpression or knockdown promoted(and inhibited)cell proliferation,migration,and invasion,which were reversed by STAT1 knockdown or overexpression.Further studies showed that TGM2 promoted GC progression by inhibiting STAT1 ubiquitination/degradation.Then,tripartite motif-containing protein 21(TRIM21)was identified as a ubiquitin E3 ligase of STAT1 in GC.TGM2 maintained STAT1 stability by facilitating the dissociation of TRIM21 and STAT1 with GTP-binding enzymatic activity.A23187 abolished the role of TGM2 in STAT1 and reversed the pro-tumor role of TGM2 in vitro and in vivo.Conclusions:This study revealed a critical role and regulatory mechanism of TGM2 on STAT1 in GC and highlighted the potential of TGM2 as a therapeutic target,which elucidates the development of medicine or strategies by regulating the GTP-binding activity of TGM2 in GC.展开更多
Protein ubiquitination regulates diverse cellular processes in eukaryotic organisms,from growth and development to stress response.Proteins subjected to ubiquitination can be found in virtually all subcellular locatio...Protein ubiquitination regulates diverse cellular processes in eukaryotic organisms,from growth and development to stress response.Proteins subjected to ubiquitination can be found in virtually all subcellular locations and organelles,including peroxisomes,singlemembrane and highly dynamic organelles ubiquitous in eukaryotes.Peroxisomes contain metabolic functions essential to plants and animals such as lipid catabolism,detoxification of reactive oxygen species(ROS),biosynthesis of vital hormones and cofactors,and photorespiration.Plant peroxisomes possess a complex proteome with functions varying among different tissue types and developmental stages,and during plant response to distinct environmental cues.However,how these diverse functions are regulated at the post-translational level is poorly understood,especially in plants.In this review,we summarized current knowledge of the involvement of protein ubiquitination in peroxisome protein import,remodeling,pexophagy,and metabolism,focusing on plants,and referencing discoveries from other eukaryotic systems when relevant.Based on previous ubiquitinomics studies,we compiled a list of 56 ubiquitinated Arabidopsis peroxisomal proteins whose functions are associated with all the major plant peroxisomal metabolic pathways.This discovery suggests a broad impact of protein ubiquitination on plant peroxisome functions,therefore substantiating the need to investigate this significant regulatory mechanism in peroxisomes at more depths.展开更多
Ischemic heart failure(HF)remains a leading cause of morbidity and mortality.Maintaining homeostasis of cardiac function and preventing cardiac remodeling deterioration are critical to halting HF progression.Methyltra...Ischemic heart failure(HF)remains a leading cause of morbidity and mortality.Maintaining homeostasis of cardiac function and preventing cardiac remodeling deterioration are critical to halting HF progression.Methyltransferase-like protein 13(Mettl13)has been shown to regulate protein translation efficiency by acting as a protein lysine methyltransferase,but its role in cardiac pathology remains unexplored.This study aims to characterize the roles and mechanisms of Mettl13 in cardiac contractile function and HF.We found that Mettl13 was downregulated in the failing hearts of mice post-myocardial infarction(MI)and in a cellular model of oxidative stress.Cardiomyocyte-specific overexpression of Mettl13 mediated by AAV9-Mettl13 attenuated cardiac contractile dysfunction and fibrosis in response to MI,while silencing of Mettl13 impaired cardiac function in normal mice.Moreover,Mettl13 overexpression abrogated the reduction in cell shortening,Ca^(2+)transient amplitude and SERCA2a protein levels in the cardiomyocytes of adult mice with MI.Conversely,knockdown of Mettl13 impaired the contractility of cardiomyocytes,and decreased Ca^(2+)transient amplitude and SERCA2a protein expression in vivo and in vitro.Mechanistically,Mettl13 impaired the stability of c-Cbl by inducing lysine methylation of c-Cbl,which in turn inhibited ubiquitination-dependent degradation of SERCA2a.Furthermore,the inhibitory effects of knocking down Mettl13 on SERCA2a protein expression and Ca^(2+)transients were partially rescued by silencing c-Cbl in H_(2)O_(2)-treated cardiomyocytes.In conclusion,our study uncovers a novel mechanism that involves the Mettl13/c-Cbl/SERCA2a axis in regulating cardiac contractile function and remodeling,and identifies Mettl13 as a novel therapeutic target for ischemic HF.展开更多
Pregnane X receptor(PXR)is a ligand-activated nuclear receptor that transcriptionally upregulates drug-metabolizing enzymes[e.g.,cytochrome P4503A4(CYP3A4)]and transporters.Although the regulation of PXR target genes ...Pregnane X receptor(PXR)is a ligand-activated nuclear receptor that transcriptionally upregulates drug-metabolizing enzymes[e.g.,cytochrome P4503A4(CYP3A4)]and transporters.Although the regulation of PXR target genes is well-characterized,less is known about the regulation of PXR protein level.By screening an RNAi library,we identified the F-box-only protein 44(FBXO44)as a novel E3ligase for PXR.PXR abundance increases upon knockdown of FBXO44,and,inversely,decreases upon overexpression of FBXO44.Further analysis revealed that FBXO44 interacts with PXR,leading to its ubiquitination and proteasomal degradation,and we determined that the F-box associated domain of FBXO44 and the ligand binding domain of PXR are required for the functional interaction.In summary,FBXO44 regulates PXR protein abundance,which has downstream consequences for CYP3A4 levels and drug-drug interactions.The results of this study provide new insight into the molecular mechanisms that regulate PXR protein level and activity and suggest the importance of considering how modulating E3ubiquitin ligase activities will affect PXR-mediated drug metabolism.展开更多
TANK-binding kinase 1(TBK1)is a nodal protein involved in multiple signal transduction pathways.In RNA virus-mediated innate immunity,TBK1 is recruited to the prion-like platform formed by MAVS and subsequently activa...TANK-binding kinase 1(TBK1)is a nodal protein involved in multiple signal transduction pathways.In RNA virus-mediated innate immunity,TBK1 is recruited to the prion-like platform formed by MAVS and subsequently activates the transcription factors IRF3/7 and NF-κB to produce type I interferon(IFN)and proinflammatory cytokines for the signaling cascade.In this study,TRAF7 was identified as a negative regulator of innate immune signaling.TRAF7 interacts with TBK1 and promotes K48-linked polyubiquitination and degradation of TBK1 through its RING domain,impairing the activation of IRF3 and the production of IFN-β.In addition,we found that the conserved cysteine residues at position 131 of TRAF7 are necessary for its function toward TBK1.Knockout of TRAF7 could facilitate the activation of IRF3 and increase the transcript levels of downstream antiviral genes.These data suggest that TRAF7 negatively regulates innate antiviral immunity by promoting the K48-linked ubiquitination of TBK1.展开更多
Osteosarcoma is a common malignant tumor occurring in children and young adults. Chondroitin sulfate (CS) participates in cell adhesion, cell division, and the formation of neural networks in the body, the biosynthesi...Osteosarcoma is a common malignant tumor occurring in children and young adults. Chondroitin sulfate (CS) participates in cell adhesion, cell division, and the formation of neural networks in the body, the biosynthesis of which requires the participation of glycosyltransferases. CHPF, a glycosyltransferase, plays a role in the extension of CS. Recently, CHPF's biological roles and functional importance in human diseases including malignant tumors have been widely discussed. However, whether CHPF is involved in osteosarcoma development and growth has not been revealed. The present work aimed to investigate the expression levels, functional significance and molecular mechanism of CHPF in osteosarcoma progression. Our results revealed that CHPF is strongly expressed in osteosarcoma tissues and cells. Furthermore, CHPF serves as a tumor promoter in the development and progression of osteosarcoma through enhancing cell proliferation and migration while suppressing apoptosis. Exploration of the mechanism by which CHPF promotes osteosarcoma indicated that CHPF promotes osteosarcoma through counteracting SKP2's ubiquitination and activating the Akt signaling pathway. For the first time, we clarified the roles of CHPF in osteosarcoma, and our results suggested that CHPF might be a novel therapeutic target in the treatment strategies for osteosarcoma.展开更多
BACKGROUND Esophageal squamous cell carcinoma(ESCC)is a deadly malignancy with limited treatment options.Deubiquitinases(DUBs)have been confirmed to play a crucial role in the development of malignant tumors.JOSD2 is ...BACKGROUND Esophageal squamous cell carcinoma(ESCC)is a deadly malignancy with limited treatment options.Deubiquitinases(DUBs)have been confirmed to play a crucial role in the development of malignant tumors.JOSD2 is a DUB involved in con-trolling protein deubiquitination and influencing critical cellular processes in cancer.AIM To investigate the impact of JOSD2 on the progression of ESCC.METHODS Bioinformatic analyses were employed to explore the expression,prognosis,and enriched pathways associated with JOSD2 in ESCC.Lentiviral transduction was utilized to manipulate JOSD2 expression in ESCC cell lines(KYSE30 and RESULTS )Preliminary research indicated that JOSD2 was highly expressed in ESCC tissues,which was associated with poor prognosis.Further analysis demonstrated that JOSD2 was upregulated in ESCC cell lines compared to normal esophageal cells.JOSD2 knockdown inhibited ESCC cell activity,including proliferation and colony-forming ability.Moreover,JOSD2 knockdown decreased the drug resistance and migration of ESCC cells,while JOSD2 overexpression enhanced these phenotypes.In vivo xenograft assays further confirmed that JOSD2 promoted tumor proliferation and drug resistance in ESCC.Mechanistically,JOSD2 appears to activate the MAPK/ERK and PI3K/AKT signaling pathways.Mass spectrometry was used to identify crucial substrate proteins that interact with JOSD2,which identified the four primary proteins that bind to JOSD2,namely USP47,IGKV2D-29,HSP90AB1,and PRMT5.CONCLUSION JOSD2 plays a crucial role in enhancing the proliferation,migration,and drug resistance of ESCC,suggesting that JOSD2 is a potential therapeutic target in ESCC.展开更多
Introduction:DNA polymerases are crucial for maintaining genome stability and influencing tumorigenesis.However,the clinical implications of DNA polymerases in tumorigenesis and their potential as anti-cancer therapy ...Introduction:DNA polymerases are crucial for maintaining genome stability and influencing tumorigenesis.However,the clinical implications of DNA polymerases in tumorigenesis and their potential as anti-cancer therapy targets are not well understood.Methods:We conducted a systematic analysis using TCGA Pan-Cancer Atlas data and Gene Set Cancer Analysis results to examine the expression profiles of 15 DNA polymerases(POLYs)and their clinical correlations.We also evaluated the prognostic value of POLYs by analyzing their expression levels in relation to overall survival time(OS)using Kaplan-Meier survival curves.Additionally,we investigated the correlations between POLY expression and immune cells,DNA damage repair(DDR)pathways,and ubiquitination.Drug sensitivity analysis was performed to assess the relationship between POLY expression and drug response.Results:Our analysis revealed that 14 out of 15 POLYs exhibited significantly distinct expression patterns between tumor and normal samples across most cancer types,except for DNA nucleotidylexotransferase(DNTT).Specifically,POLD1 and POLE showed elevated expression in almost all cancers,while POLQ exhibited high expression levels in all cancer types.Some POLYs showed heightened expression in specific cancer subtypes,while others exhibited low expression.Kaplan-Meier survival curves demonstrated significant prognostic value of POLYs in multiple cancers,including PAAD,KIRC,and ACC.Cox analysis further validated these findings.Alteration patterns of POLYs varied significantly among different cancer types and were associated with poorer survival outcomes.Significant correlations were observed between the expression of POLY members and immune cells,DDR pathways,and ubiquitination.Drug sensitivity analysis indicated an inverse relationship between POLY expression and drug response.Conclusion:Our comprehensive study highlights the significant role of POLYs in cancer development and identifies them as promising prognostic and immunological biomarkers for various cancer types.Additionally,targeting POLYs therapeutically holds promise for tumor immunotherapy.展开更多
Polyphyllin I(PPI)purified from Polyphylla rhizomes displays puissant cytotoxicity in many kinds of cancers.Several researches investigated its anti-cancer activity.But novel mechanisms are still worth investigation.T...Polyphyllin I(PPI)purified from Polyphylla rhizomes displays puissant cytotoxicity in many kinds of cancers.Several researches investigated its anti-cancer activity.But novel mechanisms are still worth investigation.This study aimed to explore PPI-induced endoplasmic reticulum(ER)stress as well as the underlying mechanism in non-small cell lung cancer(NSCLC).Cell viability or colony-forming was detected by MTT or crystal violet respectively.Cell cycle,apoptosis,reactive oxygen species(ROS)and mitochondrial membrane potential were assessed by flow cytometry.Gene and protein levels were evaluated by q RT-PCR and immunoblotting respectively.Protein interaction was determined by immunoprecipitation or immunofluorescence assay.Gene overexpression or silencing was carried out by transient transfection with plasmids or small interfering RNAs.The Cancer Genome Atlas(TCGA)database was used for Gene Set Enrichment Analysis(GSEA),survival analysis,gene expression statistics or pathway enrichment assay.PPI inhibited the propagation of NSCLC cells,increased non-viable apoptotic cells,arrested cell cycle at G2/M phase,induced ROS levels but failed to decrease mitochondrial membrane potential.High levels of GRP78 indicates poor prognosis in NSCLC patients.PPI selectively suppressed unfolded protein response(UPR)-induced GRP78 expression,subsequently protected CHOP from GRP78-mediated ubiquitination and degradation.We demonstrated that the natural product PPI,obtained from traditional herbal medicine,deserves for further study as a valuable candidate for lead compound in the chemotherapy of NSCLC.展开更多
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.
基金This study was supported by grants from the National Natural Science Foundation of China(81873592)the graduate tutor team construction project of Chongqing Municipal Education Commission Foundation(dstd201801).
文摘Background:NOD-like receptor family CARD domain containing 3(NLRC3)plays an important role in both innate and adaptive immunity.This study was to explore the function and related mechanisms of NLRC3 in a hypoxia/reoxygenation(H/R)-induced inflammatory response in RAW264.7 cells.Methods:Liver ischemia-reperfusion(I/R)model in mice and H/R model in RAW264.7 cells were constructed.Western blotting was used to determine the protein expression level of NLRC3 in liver tissue and NLRC3,TRAF6,p–p65,p65,IκB–α,and the K63-linked ubiquitination level of TRAF6 in cells.The immunofluorescence assay was performed to evaluate the nuclear level of the NF–κB(p65).ELISA was conducted to measure the content of IL–1βin serum and cell supernatant.The interaction between NLRC3 and TRAF6 in cells was analyzed by the Co-IP assay.Results:The NLRC3 protein level in liver tissue was decreased with the prolongation of reperfusion time(P<0.05).The expression of NLRC3 and IκB–αprotein in RAW264.7 was decreased gradually,while the expression of p–p65 and TRAF6 proteins and K63-linked ubiquitination of TRAF6 were increased gradually with the prolongation of reoxgenation time(P<0.05).The Co-IP assay revealed that NLRC3 and TRAF6 can bind to each other directly.However,NLRC3 had no effect on the expression of TRAF6 protein.The ubiquitination test results showed that the K63-linked ubiquitination level of TRAF6 in H/R+Lv–NLRC3 group was significantly lower than that in the H/R+negative control(NC)group(P<0.05).Moreover,the activation of NF–κB in H/R+Lv–NLRC3 group was inhibited compared with that in the H/R+NC group,and the level of the inflammatory factor IL–1βin the cell culture supernatant was also decreased accordingly(P<0.05).Conclusions:NLRC3 might alleviate H/R-induced inflammation in RAW264.7 cells by inhibiting K63-linked ubiquitination of TRAF6.
文摘Lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma) is the most common extranodal B cell tumor and accounts for 8% of non-Hodgkin's lymphomas. Gastric MALT lymphoma is the best-studied example and is a prototypical neoplasm that occurs in the setting of chronic inflammation brought on by persistent infection or autoimmune disease. Cytogenetic abnormalities are commonly acquired during the course of disease and the most common is chromosomal translocation t(11;18)(q21;q21), which creates the API2-MALT1 fusion oncoprotein. t(11;18)-positive lymphomas can be clinically aggressive and have a higher rate of dissemination than t(11;18)-negative tumors. Many cancers, including MALT lymphomas, characteristically exhibit deregulated over-activation of cellular survival pathways, such as the nuclear factor-κB(NF-κB) pathway. Molecular characterization of API2-MALT1 has revealed it to be a potent activator of NF-κB, which is required for API2-MALT1-induced cellular transformation, however the mechanisms by which API2-MALT1 exerts these effects are only recently becoming apparent. The API2 moiety of the fusion binds tumor necrosis factor(TNF) receptor associated factor(TRAF) 2 and receptor interacting protein 1(RIP1), two proteins essential for TNF receptor induced NF-κB activation. By effectively mimicking ligand-bound TNF receptor, API2-MALT1 promotes TRAF2-dependent ubiquitination of RIP1, which then acts as a scaffold for nucleating and activating the canonical NF-κB machinery. Activation occurs, in part, through MALT1 moiety-dependent recruitment of TRAF6, which can directly modify NF-κB essential modulator, the principal downstream regulator of NF-κB. While theintrinsic MALT1 protease catalytic activity is dispensable for this canonical NF-κB signaling, it is critical for noncanonical NF-κB activation. In this regard, API2-MALT1 recognizes NF-κB inducing kinase(NIK), the essential upstream regulator of non-canonical NF-κB, and cleaves it to generate a stable, constitutively active fragment. Thus, API2-MALT1 harnesses multiple unique pathways to achieve deregulated NF-κB activation. Emerging data from our group and others have also detailed additional gain-of-function activities of API2-MALT1 that extend beyond NF-κB activation. Specifically, API2-MALT1 recruits and subverts multiple other signaling factors, including LIM domain and actin-binding protein 1(LIMA1) and Smac/DIABLO. Like NIK, LIMA1 represents a unique substrate for API2-MALT1 protease activity, but unlike NIK, its cleavage sets in motion a major NF-κB-independent pathway for promoting oncogenesis. In this review, we highlight the most recent results characterizing these unique and diverse gain-of-function activities of API2-MALT1 and how they contribute to lymphomagenesis.
基金supported by grants from the National Key Research and Development Program of China(2018YFD1000200)the National Natural Science Foundation of China(31972375)+1 种基金Ministry of Agriculture(CARS-27)Shandong Province(SDAIT-06-03).
文摘As an important primary metabolite,malate plays a key role in regulating osmotic pressure,pH homeostasis,stress tolerance,and fruit quality of apple.The R2R3-MYB transcription factor(TF)MdMYB73 was identified as a protein that plays a critical role in determining malate accumulation and vacuolar acidification by directly regulating the transcription of aluminum-activated malate transporter 9(MdALMT9),vacuolar ATPase subunit A(MdVHA-A),and vacuolar pyrophosphatase 1(MdVHP1)in apple.In addition,the bHLH TF MdCIbHLH1 interacts with MdMYB73 and enhances the transcriptional activity of MdMYB73.Our previous studies demonstrated that the BTB-BACK-TAZ domain protein MdBT2 can degrade MdCIbHLH1 to influence malate accumulation and vacuolar acidification.However,the potential upstream regulators of MdMYB73 are currently unknown.In this study,we found that MdBT2 directly interacts with and degrades MdMYB73 through the ubiquitin/26S proteasome pathway to regulate malate accumulation and vacuolar acidification.A series of functional assays with apple calli and fruit showed that MdBT2 controls malate accumulation and vacuolar acidification in an MdMYB73-dependent manner.Overall,our findings shed light on the mechanism by which the BTB-BACK-TAZ domain protein MdBT2 regulates malate accumulation and vacuolar acidification by targeting MdMYB73 and MdCIbHLH1 for ubiquitination in apple.This information may help guide traditional breeding programs and fruit tree molecular breeding,and lead to improvements in fruit quality and stress tolerance.
基金Supported by Grants from National Basic Research Program of China,973 program,No.2010CB529704 and No.2012CB910404National Natural Science Foundation of China,No.30800587,No.30971521,and No.31171338+1 种基金the Science and Technology Commission of Shanghai Municipality,No.11DZ2260300a scholar of the Shanghai Rising-Star Program from Science and Technology Commission of Shanghai Municipality,No.09QA1401900 to Wang P
文摘Krüppel-like factor(KLF) family proteins are transcription factors that regulate numerous cellular functions, such as cell proliferation, differentiation, and cell death. Posttranslational modification of KLF proteins is important for their transcriptional activities and biological functions. One KLF family member with important roles in cell proliferation and tumorigenesis is KLF5. The function of KLF5 is tightly controlled by post-translational modifications, including SUMOylation, phosphorylation, and ubiquitination. Recent studies from our lab and others' have demonstrated that the tumor suppressor FBW7 is an essential E3 ubiquitin ligase that targets KLF5 for ubiquitination and degradation. KLF5 contains functional Cdc4 phospho-degrons(CPDs), which are required for its interaction with FBW7. Mutation of CPDs in KLF5 blocks the ubiquitination and degradation of KLF5 by FBW7. The protein kinase Glycogen synthase kinase 3β is involved in the phosphorylation of KLF5 CPDs. In both cancer cell lines and mousemodels, it has been shown that FBW7 regulates the expression of KLF5 target genes through the modulation of KLF5 stability. In this review, we summarize the current progress on delineating FBW7-mediated KLF5 ubiquitination and degradation.
基金This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhejiang University School of Medicine(Ethics Code 2021-384)All animal experiments were approved by the Animal Care Committee of Zhejiang University(Ethics Code 2019-1218)were conducted in strict accordance with the National Institutes of Health Animal Care and Use Guidelines.
文摘Background:Liver cancer is a malignancy with high morbidity and mortality rates.Serpin family E member 2(SERPINE2)has been reported to play a key role in the metastasis of many tumors.In this study,we aimed to investigate the potential mechanism of SERPINE2 in liver cancer metastasis.Methods:The Cancer Genome Atlas database(TCGA),including DNA methy-lation and transcriptome sequencing data,was utilized to identify the crucial oncogene associated with DNA methylation and cancer progression in liver can-cer.Data from the TCGA and RNA sequencing for 94 pairs of liver cancer tissues were used to explore the correlation between SERPINE2 expression and clin-ical parameters of patients.DNA methylation sequencing was used to detect the DNA methylation levels in liver cancer tissues and cells.RNA sequencing,cytokine assays,immunoprecipitation(IP)and mass spectrometry(MS)assays,protein stability assays,and ubiquitination assays were performed to explore the regulatory mechanism of SERPINE2 in liver cancer metastasis.Patient-derived xenografts and tumor organoid models were established to determine the role of SERPINE2 in the treatment of liver cancer using sorafenib.Results:Based on the public database screening,SERPINE2 was identified as a tumor promoter regulated by DNA methylation.SERPINE2 expression was significantly higher in liver cancer tissues and was associated with the dismal prognosis in patients with liver cancer.SERPINE2 promoted liver cancer metas-tasis by enhancing cell pseudopodia formation,cell adhesion,cancer-associated fibroblast activation,extracellular matrix remodeling,and angiogenesis.IP/MS assays confirmed that SERPINE2 activated epidermal growth factor receptor(EGFR)and its downstream signaling pathways by interacting with EGFR.Mechanistically,SERPINE2 inhibited EGFR ubiquitination and maintained its protein stability by competing with the E3 ubiquitin ligase,c-Cbl.Additionally,EGFR was activated in liver cancer cells after sorafenib treatment,and SER-PINE2 knockdown-induced EGFR downregulation significantly enhanced the therapeutic efficacy of sorafenib against liver cancer.Furthermore,we found that SERPINE2 knockdown also had a sensitizing effect on lenvatinib treatment.Conclusions:SERPINE2 promoted liver cancer metastasis by preventing EGFR degradation via c-Cbl-mediated ubiquitination,suggesting that inhibition of the SERPINE2-EGFR axis may be a potential target for liver cancer treatment.
基金supported by the Taishan Scholars Program of Shandong Province (No.tsqn201909101)the National Natural Science Foundation of China (Nos.21976114,92043202 and 91943301)。
文摘Tetrabromobisphenol A(TBBPA)and its derivatives widely exist in various environments and biota.Although the available data indicate that TBBPA exposure is highly associated with the increased incidence of endometrial cancer(EC),the effects of TBBPA and its main derivatives on EC proliferation and the involved crucial mechanism remain unclear.The present study aimed to investigate the effects of TBBPA and its derivatives under environmental concentrations on the proliferation of EC,and the crucial mechanism on the progression of EC caused by bromine fame retardants exposure.In this research,TBBPA and two of the most common TBBPA derivatives including TBBPA bis(2-hydroxyethyl ether)(TBBPABHEE)and TBBPA bis(dibromopropyl ether)(TBBPA-BDBPE)were screened for their capacities in induced EC proliferation and explored the related mechanism by in vitro cell culture model and in vivo mice model.Under environmental concentrations,TBBPA promoted the proliferation of EC,the main derivatives of TBBPA(TBBPA-BHEE and TBBPA-BDBPE)did not present the similar facilitation effects.The ubiquitination degradation of p53 was crucial in TBBPA induced EC proliferation,which resulted in the increase of downstream cell cycle and decrease of apoptosis.The further molecular docking result suggested the high affinity between TBBPA and ubiquitinated proteasome.This finding revealed the effects of TBBPA and its derivatives on EC proliferation,thus providing novel insights into the underlying mechanisms of TBBPA-caused EC.
基金supported by The National Natural Science Foundation of China(No.81770154,81970194,and 82170176)the National Key Research and Development Program of China(No.2022YFC2705003)+1 种基金Guangzhou Medical University Discipline Construction Funds(Basic Medicine)(China)(No.JCXKJS2022A05)Guangzhou Key Discipline of Medicine(Geriatric Medicine)(China)(No.ZDXK202103).
文摘Chronic myelogenous leukemia(CML)is a malignancy from bone marrow myeloid stem cells mainly driven by the fusion gene BCR-ABL.In addition to BCR-ABL,other genes including RNF6 are also dysregulated in CML cells.1 RNF6,a ubiquitin ligase of the RING family,promotes various cancer cell proliferation,chemoresistance,and tumor growth in vivo by targeting various proteins for ubiquitination and degradation,including SHP1,TLE3,FOXA1,and MAD1.^(2) However,its specific mechanism in CML is not known.
基金supported by the National Natural Science Foundation of China(82103508,81871866,82173252)Shaanxi Special Support Plan-Program for Leading Talents of Science and Technology Innovation(China)(No.2019 Special Support Plan)+1 种基金the Natural Science Foundation of Shaanxi Province(China)(2016SF-308,2019SF-033,2022SF-145)Project of Tangdu Hospital,the Fourth Military Medical University(China)(No.2018 Key Talents).
文摘As members of the immune checkpoint family, PD-1 and its ligand PD-L1 play critical roles in maintaining the balance between autoimmunity and tolerance. The interaction of PD-1/PD-L1 is also involved in tumor evasion inside the tumor microenvironment, caused by reduced T cell activation, proliferation, cytotoxic secretion, and survival. Previous research has shown that the expression level of PD-1/PD-L1 may be regulated by ubiquitin-mediated proteasome degradation, which is an important mode of post-translational modification (PTM). PD-1/PD-L1 ubiquitin modification research in tumor immunotherapy is the subject of the present review, which aims to assess the most recent developments in this area. We offer a short explanation of PD-1/PD-L1 as well as some basic background information on the UPS system and discuss many routes that target E3s and DUBs, respectively, in the regulation of PD-1/PD-L1 in tumor immunotherapy. In addition, we offer numerous innovative prospective research areas for the future, as well as novel immunotherapy concepts and ideas. Taken together, the information compiled herein should serve as a comprehensive repository of information about tumor immunotherapy that is currently available, and it should be useful in the design of future studies, as well as the development of potential targets and strategies for future tumor immunotherapy.
基金the National Natural Science Foundation of China(81802996,81871946,and 82072708)Special Foundation for National Science and Technology Basic Research Program of China(2019FY101104)+2 种基金the Program for Development of Innovative Research Team in the First Affiliated Hospital of NJMUthe Priority Academic ProgramDevelopment of JiangsuHigher Education Institutions(JX10231801)Jiangsu Key Medical Discipline(General Surgery)(ZDXKA2016005),Jiangsu Key Lab of Cancer Biomarkers,Prevention and Treatment,Collaborative Innovation Center for Cancer Personalized Medicine,Nanjing Medical University.
文摘Background:Previous studies have revealed the critical role of transglutaminase 2(TGM2)as a potential therapeutic target in cancers,but the oncogenic roles and underlying mechanisms of TGM2 in gastric cancer(GC)are not fully understood.In this study,we examined the role and potential mechanism of TGM2 in GC.Methods:Western blotting,immunohistochemistry,CCK8,colony formation and transwell assays were used to measure TGM2 expression in the GC cells and tissues and to examine the in vitro role of TGM2 in GC.Xenograft and in vivo metastasis experiments were performed to examine the in vivo role of TGM2 in GC.Gene set enrichment analysis,quantitative PCR and western blotting were conducted to screen for potential TGM2 targets involved in GC.Gain/loss-offunction and rescue experiments were conducted to detect the biological roles of STAT1 in GC cells in the context of TGM2.Co-immunoprecipitation,mass spectrometry,quantitative PCR and western blotting were conducted to identify STAT1-interacting proteins and elucidate their regulatory mechanisms.Mutations in TGM2 and two molecules(ZM39923 and A23187)were used to identify the enzymatic activity of TGM2 involved in the malignant progression of GC and elucidate the underlying mechanism.Results:In this study,we demonstrated elevated TGM2 expression in the GC tissues,which closely related to pathological grade,and predicted poor survival in patients with GC.TGM2 overexpression or knockdown promoted(and inhibited)cell proliferation,migration,and invasion,which were reversed by STAT1 knockdown or overexpression.Further studies showed that TGM2 promoted GC progression by inhibiting STAT1 ubiquitination/degradation.Then,tripartite motif-containing protein 21(TRIM21)was identified as a ubiquitin E3 ligase of STAT1 in GC.TGM2 maintained STAT1 stability by facilitating the dissociation of TRIM21 and STAT1 with GTP-binding enzymatic activity.A23187 abolished the role of TGM2 in STAT1 and reversed the pro-tumor role of TGM2 in vitro and in vivo.Conclusions:This study revealed a critical role and regulatory mechanism of TGM2 on STAT1 in GC and highlighted the potential of TGM2 as a therapeutic target,which elucidates the development of medicine or strategies by regulating the GTP-binding activity of TGM2 in GC.
基金supported by the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2019R01002)Key Research Project of Zhejiang Laboratory(No.2021PE0AC04)+3 种基金Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202148338)Zhejiang University Student Research Practice Program(No.P2021041)to R.P.by the National Science Foundation(No.MCB 2148206)US Department of Energy(No.DEFG02-91ER20021)to J.H。
文摘Protein ubiquitination regulates diverse cellular processes in eukaryotic organisms,from growth and development to stress response.Proteins subjected to ubiquitination can be found in virtually all subcellular locations and organelles,including peroxisomes,singlemembrane and highly dynamic organelles ubiquitous in eukaryotes.Peroxisomes contain metabolic functions essential to plants and animals such as lipid catabolism,detoxification of reactive oxygen species(ROS),biosynthesis of vital hormones and cofactors,and photorespiration.Plant peroxisomes possess a complex proteome with functions varying among different tissue types and developmental stages,and during plant response to distinct environmental cues.However,how these diverse functions are regulated at the post-translational level is poorly understood,especially in plants.In this review,we summarized current knowledge of the involvement of protein ubiquitination in peroxisome protein import,remodeling,pexophagy,and metabolism,focusing on plants,and referencing discoveries from other eukaryotic systems when relevant.Based on previous ubiquitinomics studies,we compiled a list of 56 ubiquitinated Arabidopsis peroxisomal proteins whose functions are associated with all the major plant peroxisomal metabolic pathways.This discovery suggests a broad impact of protein ubiquitination on plant peroxisome functions,therefore substantiating the need to investigate this significant regulatory mechanism in peroxisomes at more depths.
基金supported by the National Natural Science Foundation of China (82273928,U21A20339)the Outstanding Youth Project of Natural Science Foundation of Heilongjiang Province (YQ2020H010)+2 种基金Youth Project of Scientific Research Institution of Heilongjiang Province (CZKYF2023-1-C047)CAMS Innovation Fund for Medical Sciences (CIFMS) (2019-I2M-5-078)Harbin Medical University Youth Talents Start-up Funding (2019-YQ-03)。
文摘Ischemic heart failure(HF)remains a leading cause of morbidity and mortality.Maintaining homeostasis of cardiac function and preventing cardiac remodeling deterioration are critical to halting HF progression.Methyltransferase-like protein 13(Mettl13)has been shown to regulate protein translation efficiency by acting as a protein lysine methyltransferase,but its role in cardiac pathology remains unexplored.This study aims to characterize the roles and mechanisms of Mettl13 in cardiac contractile function and HF.We found that Mettl13 was downregulated in the failing hearts of mice post-myocardial infarction(MI)and in a cellular model of oxidative stress.Cardiomyocyte-specific overexpression of Mettl13 mediated by AAV9-Mettl13 attenuated cardiac contractile dysfunction and fibrosis in response to MI,while silencing of Mettl13 impaired cardiac function in normal mice.Moreover,Mettl13 overexpression abrogated the reduction in cell shortening,Ca^(2+)transient amplitude and SERCA2a protein levels in the cardiomyocytes of adult mice with MI.Conversely,knockdown of Mettl13 impaired the contractility of cardiomyocytes,and decreased Ca^(2+)transient amplitude and SERCA2a protein expression in vivo and in vitro.Mechanistically,Mettl13 impaired the stability of c-Cbl by inducing lysine methylation of c-Cbl,which in turn inhibited ubiquitination-dependent degradation of SERCA2a.Furthermore,the inhibitory effects of knocking down Mettl13 on SERCA2a protein expression and Ca^(2+)transients were partially rescued by silencing c-Cbl in H_(2)O_(2)-treated cardiomyocytes.In conclusion,our study uncovers a novel mechanism that involves the Mettl13/c-Cbl/SERCA2a axis in regulating cardiac contractile function and remodeling,and identifies Mettl13 as a novel therapeutic target for ischemic HF.
基金supported by the National Institutes of Health National Institute of General Medical Sciences[Grant R35GM118041]supported in part by the National Cancer Institute of the National Institutes of Health under Award Number P30 CA021765。
文摘Pregnane X receptor(PXR)is a ligand-activated nuclear receptor that transcriptionally upregulates drug-metabolizing enzymes[e.g.,cytochrome P4503A4(CYP3A4)]and transporters.Although the regulation of PXR target genes is well-characterized,less is known about the regulation of PXR protein level.By screening an RNAi library,we identified the F-box-only protein 44(FBXO44)as a novel E3ligase for PXR.PXR abundance increases upon knockdown of FBXO44,and,inversely,decreases upon overexpression of FBXO44.Further analysis revealed that FBXO44 interacts with PXR,leading to its ubiquitination and proteasomal degradation,and we determined that the F-box associated domain of FBXO44 and the ligand binding domain of PXR are required for the functional interaction.In summary,FBXO44 regulates PXR protein abundance,which has downstream consequences for CYP3A4 levels and drug-drug interactions.The results of this study provide new insight into the molecular mechanisms that regulate PXR protein level and activity and suggest the importance of considering how modulating E3ubiquitin ligase activities will affect PXR-mediated drug metabolism.
基金National Natural Science Foundation of China(Grant Nos.81971502,82060298,31570876).
文摘TANK-binding kinase 1(TBK1)is a nodal protein involved in multiple signal transduction pathways.In RNA virus-mediated innate immunity,TBK1 is recruited to the prion-like platform formed by MAVS and subsequently activates the transcription factors IRF3/7 and NF-κB to produce type I interferon(IFN)and proinflammatory cytokines for the signaling cascade.In this study,TRAF7 was identified as a negative regulator of innate immune signaling.TRAF7 interacts with TBK1 and promotes K48-linked polyubiquitination and degradation of TBK1 through its RING domain,impairing the activation of IRF3 and the production of IFN-β.In addition,we found that the conserved cysteine residues at position 131 of TRAF7 are necessary for its function toward TBK1.Knockout of TRAF7 could facilitate the activation of IRF3 and increase the transcript levels of downstream antiviral genes.These data suggest that TRAF7 negatively regulates innate antiviral immunity by promoting the K48-linked ubiquitination of TBK1.
基金conducted with support from the Shandong Provincial Natural Science Foundation,China(No.201910230366).
文摘Osteosarcoma is a common malignant tumor occurring in children and young adults. Chondroitin sulfate (CS) participates in cell adhesion, cell division, and the formation of neural networks in the body, the biosynthesis of which requires the participation of glycosyltransferases. CHPF, a glycosyltransferase, plays a role in the extension of CS. Recently, CHPF's biological roles and functional importance in human diseases including malignant tumors have been widely discussed. However, whether CHPF is involved in osteosarcoma development and growth has not been revealed. The present work aimed to investigate the expression levels, functional significance and molecular mechanism of CHPF in osteosarcoma progression. Our results revealed that CHPF is strongly expressed in osteosarcoma tissues and cells. Furthermore, CHPF serves as a tumor promoter in the development and progression of osteosarcoma through enhancing cell proliferation and migration while suppressing apoptosis. Exploration of the mechanism by which CHPF promotes osteosarcoma indicated that CHPF promotes osteosarcoma through counteracting SKP2's ubiquitination and activating the Akt signaling pathway. For the first time, we clarified the roles of CHPF in osteosarcoma, and our results suggested that CHPF might be a novel therapeutic target in the treatment strategies for osteosarcoma.
基金Supported by Tianjin Key Medical Discipline(Specialty)Construction Project,No.TJYXZDXK-009ATianjin Medical University Cancer Hospital National Natural Science Foundation Cultivation Program,No.220108+3 种基金National Natural Science Foundation of China,No.82373134Science and Technology Development Fund of Tianjin Education Commission for Higher Education,No.2022KJ228Chinese Anti-Cancer Association-Heng Rui Anti-angiogenesis Targeted Tumor Research Fund,No.2021001045and Scientific Research Translational Foundation of Wenzhou Safety(Emergency)Institute of Tianjin University,No.TJUWYY2022025.
文摘BACKGROUND Esophageal squamous cell carcinoma(ESCC)is a deadly malignancy with limited treatment options.Deubiquitinases(DUBs)have been confirmed to play a crucial role in the development of malignant tumors.JOSD2 is a DUB involved in con-trolling protein deubiquitination and influencing critical cellular processes in cancer.AIM To investigate the impact of JOSD2 on the progression of ESCC.METHODS Bioinformatic analyses were employed to explore the expression,prognosis,and enriched pathways associated with JOSD2 in ESCC.Lentiviral transduction was utilized to manipulate JOSD2 expression in ESCC cell lines(KYSE30 and RESULTS )Preliminary research indicated that JOSD2 was highly expressed in ESCC tissues,which was associated with poor prognosis.Further analysis demonstrated that JOSD2 was upregulated in ESCC cell lines compared to normal esophageal cells.JOSD2 knockdown inhibited ESCC cell activity,including proliferation and colony-forming ability.Moreover,JOSD2 knockdown decreased the drug resistance and migration of ESCC cells,while JOSD2 overexpression enhanced these phenotypes.In vivo xenograft assays further confirmed that JOSD2 promoted tumor proliferation and drug resistance in ESCC.Mechanistically,JOSD2 appears to activate the MAPK/ERK and PI3K/AKT signaling pathways.Mass spectrometry was used to identify crucial substrate proteins that interact with JOSD2,which identified the four primary proteins that bind to JOSD2,namely USP47,IGKV2D-29,HSP90AB1,and PRMT5.CONCLUSION JOSD2 plays a crucial role in enhancing the proliferation,migration,and drug resistance of ESCC,suggesting that JOSD2 is a potential therapeutic target in ESCC.
基金supported by the project of funds by the Consultation of Provincial Department and University for S&T Innovation granted by Hebei Provincial Department of Science and Technology and Hebei Medical University(2020TXZH04).
文摘Introduction:DNA polymerases are crucial for maintaining genome stability and influencing tumorigenesis.However,the clinical implications of DNA polymerases in tumorigenesis and their potential as anti-cancer therapy targets are not well understood.Methods:We conducted a systematic analysis using TCGA Pan-Cancer Atlas data and Gene Set Cancer Analysis results to examine the expression profiles of 15 DNA polymerases(POLYs)and their clinical correlations.We also evaluated the prognostic value of POLYs by analyzing their expression levels in relation to overall survival time(OS)using Kaplan-Meier survival curves.Additionally,we investigated the correlations between POLY expression and immune cells,DNA damage repair(DDR)pathways,and ubiquitination.Drug sensitivity analysis was performed to assess the relationship between POLY expression and drug response.Results:Our analysis revealed that 14 out of 15 POLYs exhibited significantly distinct expression patterns between tumor and normal samples across most cancer types,except for DNA nucleotidylexotransferase(DNTT).Specifically,POLD1 and POLE showed elevated expression in almost all cancers,while POLQ exhibited high expression levels in all cancer types.Some POLYs showed heightened expression in specific cancer subtypes,while others exhibited low expression.Kaplan-Meier survival curves demonstrated significant prognostic value of POLYs in multiple cancers,including PAAD,KIRC,and ACC.Cox analysis further validated these findings.Alteration patterns of POLYs varied significantly among different cancer types and were associated with poorer survival outcomes.Significant correlations were observed between the expression of POLY members and immune cells,DDR pathways,and ubiquitination.Drug sensitivity analysis indicated an inverse relationship between POLY expression and drug response.Conclusion:Our comprehensive study highlights the significant role of POLYs in cancer development and identifies them as promising prognostic and immunological biomarkers for various cancer types.Additionally,targeting POLYs therapeutically holds promise for tumor immunotherapy.
基金the National Natural Science Foundation of China(Nos.81973524 and 81703754)the 111 Project from Ministry of Education of China and the State Administration of Foreign Export Affairs of China(B18056)+2 种基金the Drug Innovation Major Project(Nos.2018ZX09711-001-007and 2018ZX09735002-003)the“Double First-Class”University Project(CPU2018GF03)the special funds for Science and Technology Development under the Guidance of the Central Government(ZY20198020)。
文摘Polyphyllin I(PPI)purified from Polyphylla rhizomes displays puissant cytotoxicity in many kinds of cancers.Several researches investigated its anti-cancer activity.But novel mechanisms are still worth investigation.This study aimed to explore PPI-induced endoplasmic reticulum(ER)stress as well as the underlying mechanism in non-small cell lung cancer(NSCLC).Cell viability or colony-forming was detected by MTT or crystal violet respectively.Cell cycle,apoptosis,reactive oxygen species(ROS)and mitochondrial membrane potential were assessed by flow cytometry.Gene and protein levels were evaluated by q RT-PCR and immunoblotting respectively.Protein interaction was determined by immunoprecipitation or immunofluorescence assay.Gene overexpression or silencing was carried out by transient transfection with plasmids or small interfering RNAs.The Cancer Genome Atlas(TCGA)database was used for Gene Set Enrichment Analysis(GSEA),survival analysis,gene expression statistics or pathway enrichment assay.PPI inhibited the propagation of NSCLC cells,increased non-viable apoptotic cells,arrested cell cycle at G2/M phase,induced ROS levels but failed to decrease mitochondrial membrane potential.High levels of GRP78 indicates poor prognosis in NSCLC patients.PPI selectively suppressed unfolded protein response(UPR)-induced GRP78 expression,subsequently protected CHOP from GRP78-mediated ubiquitination and degradation.We demonstrated that the natural product PPI,obtained from traditional herbal medicine,deserves for further study as a valuable candidate for lead compound in the chemotherapy of NSCLC.
