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1.
Article in Chinese | WPRIM | ID: wpr-980756

ABSTRACT

OBJECTIVE@#To observe the effects of herbal cake separated moxibustion on macrophage effector molecule T-cell immunoglobulin and mucin-domain containing-4 (Tim-4) and ubiquitination of programmed cell death protein 1 (PD-1) in rabbits with immunosuppression, and to explore the possible mechanism on herbal cake separated moxibustion in improving immunosuppression.@*METHODS@#Thirty-two big-ear white rabbits were randomly divided into a normal group, a model group, a moxa stick moxibustion group and a herbal cake separated moxibustion group, 8 rabbits in each group. Except the normal group, the immunosuppression model was established by intraperitoneal injection of cyclophosphamide of60 mg/kg in the other 3 groups. "Shenque" (CV 8), "Shenshu" (BL 23), "Zusanli" (ST 36), etc. were selected in both the moxa stick moxibustion group and the herbal cake separated moxibustion group. Moxa stick moxibustion was applied in the moxa stick moxibustion group, one cone at each acupoint; herbal cake separated moxibustion was applied in the herbal cake separated moxibustion group, 5 cones at each acupoint. The intervention was given once every other day for 10 times in both groups. Leukocyte content in peripheral blood was detected by blood cell analyzer; the positive expression of PD-1 in CD+4 T lymphocytes, CD+8T lymphocytes and CD+68 macrophages in peripheral blood was measured by flow cytometry, the serum levels of interleukin 2 (IL-2), CD8, CD68 and Tim-4 were detected by ELISA, and the expression of Tim-4 and F-box only protein 38 (FBXO38) in the liver and spleen tissues was measured by immunohistochemistry.@*RESULTS@#Compared with the normal group, in the model group, white blood cell count (WBC) and percentage of neutrophils (NEU%) were decreased while percentage of lymphocyte (LYM%) was increased (P<0.01) in peripheral blood; the positive expression rates of PD-1 in CD+4 T lymphocytes, CD+8T lymphocytes and CD+68 macrophages in peripheral blood were increased (P<0.01); the serum levels of IL-2, CD68 and Tim-4 were increased (P<0.01), the serum level of CD8 was decreased (P<0.01); the average optical density (AOD) of Tim-4 in the liver tissue and FBXO38 in the liver and spleen tissues was increased (P<0.01). Compared with the model group, in the moxa stick moxibustion group and the herbal cake separated moxibustion group, WBC and NEU% were increased (P<0.01); the positive expression rates of PD-1 in CD+4 T lymphocytes, CD+8T lymphocytes and CD+68 macrophages in peripheral blood were decreased (P<0.01); the serum levels of IL-2, CD68 and Tim-4 were decreased (P<0.01), the serum levels of CD8 were increased (P<0.01); the AOD of Tim-4 and FBXO38 in the liver tissue and FBXO38 in the spleen tissue was decreased (P<0.01, P<0.05). Compared with the moxa stick moxibustion group, in the herbal cake separated moxibustion group, the positive expression rate of PD-1 in CD+68 macrophages in peripheral blood was increased (P<0.05); serum level of Tim-4 was increased (P<0.01); AOD of Tim-4 in the liver tissue was decreased (P<0.05).@*CONCLUSION@#Herbal cake separated moxibustion can improve immunosuppression by regulating the expression of macrophage effector molecule Tim-4 and the FBXO38 mediated ubiquitination of PD-1, Tim-4 may be one of the specific indexes of immunomodulation involving with herbal cake separated moxibustion.


Subject(s)
Animals , Rabbits , Interleukin-2/genetics , Moxibustion , Programmed Cell Death 1 Receptor/genetics , Immunosuppression Therapy , Ubiquitination
2.
Article in Chinese | WPRIM | ID: wpr-941036

ABSTRACT

OBJECTIVE@#To observe the expression of c-Myc protein in cervical cancer HeLa cells and explore the effect of juglone on the proliferation and apoptosis of HeLa cells by affecting c-Myc ubiquitination.@*METHODS@#HeLa cells treated with different concentrations (0, 10, 20, or 50 μmol/L) of juglone or with 20 μmol/L juglone for different time lengths were examined for expression of c-Myc protein with Western blotting. The half-life of c-Myc protein was determined using cycloheximide (CHX) and c-Myc protein degradation was detected using coimmunoprecipitation. We also assessed the effects of 20 μmol/L juglone combined with 0, 1.0 or 2.0 μmol/L MG132 (a proteasome inhibitor) on c-Myc expression. The effects of 20 μmol/L juglone on the proliferation and apoptosis of HeLa cells with RNA interference-mediated knockdown of c-Myc were evaluated with MTT assay and flow cytometry.@*RESULTS@#Treatment with juglone significantly lowered c-Myc protein expression in HeLa cells in a concentration-and time-dependent manner (P < 0.05). Juglone obviously shortened the half-life of c-Myc protein, and the addition of MG132 significantly up-regulated the expression level of c-Myc protein (P < 0.05). Juglone treatment also promoted ubiquitination of c-Myc protein in HeLa cells. Compared with the cells transfected with a negative control construct, the cells transfected with si-c-Myc showed significantly decreased proliferation inhibition and a lowered cell rate with early apoptosis after juglone treatment (P < 0.05).@*CONCLUSION@#Juglone inhibits proliferation and promotes apoptosis of HeLa cells by affecting the ubiquitination of c-Myc protein.


Subject(s)
Female , Humans , Apoptosis , Cell Proliferation , HeLa Cells , Naphthoquinones , Ubiquitination , Uterine Cervical Neoplasms/genetics
3.
Article in Chinese | WPRIM | ID: wpr-936284

ABSTRACT

OBJECTIVE@#To explore the role of TRIM21 in modulating the invasive phenotype of hepatocellular carcinoma (HCC) cells and its mechanism of action.@*METHODS@#RNA interference technique was used to knock down the expression of TRIM21 and β-catenin, alone or in combination, in HCC cell lines 97H and LM3, and the interfering efficiency and the activity of closely related pathways were determined using Western blotting. The two cells with TRIM21 knockdown (siTRIM21 97H and siTRIM21 LM3 cells) were assessed for their invasion ability in vitro using Transwell invasion assay, and the lung metastasis capacity of siTRIM21 LM3 cells following tail vein injection was evaluated in nude mice. The binding of TRIM21 with β-catenin and the ubiquitylation level of β-catenin in TRIM21-overexpressing HEK293 cells were determined with Western blotting and co-immunoprecipitation assay. We also compared the overall survival of patients with CTNNB1highTRIM21high and CTNNB1highTRIM21low HCC subtypes using Kaplan-Meier method based on filtrated and grouped HCC clinical data from TCGA database.@*RESULTS@#TRIM21 knockdown significantly enhanced the invasion ability of 97H and LM3 cells in vitro (P < 0.01 or 0.05) and the lung metastasis ability of LM3 cells in nude mice (P < 0.01), and simultaneous knockdown of β -catenin obviously suppressed the in vitro invasiveness of the cells (P < 0.0001 or 0.05). Co-immunoprecipitation assay showed that TRIM21 was capable of directly binding with β-catenin protein to accelerate the ubiquitination and degradation of the latter, leading to inhibition of nuclear translocation of β-catenin and hence reduced invasiveness of HCC cells. Bioinformatic analysis showed that compared patients with CTNNB1highTRIM21low HCC subtype where Wnt pathway was activated, the patients with CTNNB1highTRIM21high HCC subtype had a significantly better survival outcomes (P < 0.05).@*CONCLUSION@#A high expression of TRIM21 suppresses the invasion of HCC cells by promoting β-catenin ubiquitylation and degradation, which possibly explains the poor prognosis of CTNNB1highTRIM21low HCC patients.


Subject(s)
Animals , Humans , Mice , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Proliferation , Gene Expression Regulation, Neoplastic , HEK293 Cells , Liver Neoplasms/pathology , Mice, Nude , Ribonucleoproteins/genetics , Ubiquitination , Wnt Signaling Pathway , beta Catenin/metabolism
4.
Chinese Journal of Biotechnology ; (12): 691-704, 2022.
Article in Chinese | WPRIM | ID: wpr-927737

ABSTRACT

Flavonoids have a variety of biological activities and have important applications in food, medicine, cosmetics, and many other fields. Naringenin is a platform chemical for the biosynthesis of many important flavonoids. Ubiquitination plays a pivotal role in the post-translational modification of proteins and participates in the regulation of cellular activities. Ubiquitinated proteins can be degraded by the ubiquitin-protease system, which is important for maintaining the physiological activities of cells, and may also exert a significant impact on the expression of exogenous proteins. In this study, a real-time in-situ detection system for ubiquitination modification has been established in Saccharomyces cerevisiae by using a fluorescence bimolecular complementation approach. The ubiquitination level of protein was characterized by fluorescence intensity. By using the approach, the potential ubiquitination sites of proteins involved in the naringenin biosynthesis pathway have been obtained. The lysine residues of the relevant ubiquitination sites were mutated to arginine to reduce the ubiquitination level. The mutants of tyrosine ammonia-lyase (FjTAL) and chalcone synthase (SjCHS, SmCHS) showed decreased fluorescence, suggested that a decreased ubiquitination level. After fermentation verification, the S. cerevisiae expressing tyrosine ammonia-lyase FjTAL mutant FjTAL-K487R accumulated 74.2 mg/L p-coumaric acid at 72 h, which was 32.3% higher than that of the original FjTAL. The strains expressing chalcone synthase mutants showed no significant change in the titer of naringenin. The results showed that mutation of the potential ubiquitination sites of proteins involved in the naringenin biosynthesis pathway could increase the titer of p-coumaric acid and have positive effect on naringenin biosynthesis.


Subject(s)
Biosynthetic Pathways , Flavanones/metabolism , Saccharomyces cerevisiae/metabolism , Ubiquitination
5.
Acta Physiologica Sinica ; (6): 117-124, 2022.
Article in Chinese | WPRIM | ID: wpr-927587

ABSTRACT

The ubiquitin-proteasome system plays an important role in protein degradation. The process of ubiquitination requires ubiquitin activating enzyme E1, ubiquitin-conjugating enzyme E2, and ubiquitin ligase E3 to complete the coordination. Our previous studies have shown that HUWE1 (HECT, UBA and WWE domain containing 1), as an E3 ubiquitin ligase, can degrade epidermal growth factor receptor (EGFR) to inhibit renal tubulointerstitial fibrosis. However, E2 ubiquitin-conjugating enzymes binding to HUWE1 are still unclear. The aim of the present study was to identify E2 ubiquitin-conjugating enzymes of HUWE1. Real-time PCR was used to identify E2 ubiquitin-conjugating enzyme that may interact with HUWE1. The expression of E2 ubiquitin-conjugating enzyme was detected in kidney of unilateral ureteral obstruction (UUO) mice and HK-2 cells treated with transforming growth factor-β (TGF-β). The results showed that the expressions of E2 ubiquitin-conjugating enzyme UBE2Q2 were significantly down-regulated at both RNA and protein levels in UUO kidneys. The expression of UBE2Q2 was also down-regulated in HK-2 cells stimulated with TGF-β, which was consistent with the change in the expression of HUWE1. These findings indicated that UBE2Q2 expression was synergistic with HUWE1 in the injured kidney. Co-immunoprecipitation (Co-IP) experiments showed that HUWE1 interacted with UBE2Q2 in HK-2 cells. The co-localization of UBE2Q2 and HUWE1 was confirmed by cell immunofluorescence staining. After knocking down UBE2Q2 by siRNA, ubiquitin binding to HUWE1 and EGFR was decreased. In sum, our results demonstrated that UBE2Q2, ubiquitin-conjugating enzyme, works with HUWE1 to mediate ubiquitination and degradation of target protein in kidney.


Subject(s)
Animals , Humans , Mice , Cell Line , Fibrosis , Kidney Diseases , Ubiquitin-Conjugating Enzymes/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination
6.
Mem. Inst. Oswaldo Cruz ; 115: e190242, 2020. tab, graf
Article in English | LILACS | ID: biblio-1091241

ABSTRACT

BACKGROUND Ubiquitin (Ub) and Ub-like proteins (Ub-L) are critical regulators of complex cellular processes such as the cell cycle, DNA repair, transcription, chromatin remodeling, signal translation, and protein degradation. Giardia intestinalis possesses an experimentally proven Ub-conjugation system; however, a limited number of enzymes involved in this process were identified using basic local alignment search tool (BLAST). This is due to the limitations of BLAST's ability to identify homologous functional regions when similarity between the sequences dips to < 30%. In addition Ub-Ls and their conjugating enzymes have not been fully elucidated in Giardia. OBJETIVE To identify the enzymes involved in the Ub and Ub-Ls conjugation processes using intelligent systems based on the hidden Markov models (HMMs). METHODS We performed an HMM search of functional Pfam domains found in the key enzymes of these pathways in Giardia's proteome. Each open reading frame identified was analysed by sequence homology, domain architecture, and transcription levels. FINDINGS We identified 118 genes, 106 of which corresponded to the ubiquitination process (Ub, E1, E2, E3, and DUB enzymes). The E3 ligase group was the largest group with 82 members; 71 of which harbored a characteristic RING domain. Four Ub-Ls were identified and the conjugation enzymes for NEDD8 and URM1 were described for first time. The 3D model for Ub-Ls displayed the β-grasp fold typical. Furthermore, our sequence analysis for the corresponding activating enzymes detected the essential motifs required for conjugation. MAIN CONCLUSIONS Our findings highlight the complexity of Giardia's Ub-conjugation system, which is drastically different from that previously reported, and provides evidence for the presence of NEDDylation and URMylation enzymes in the genome and transcriptome of G. intestinalis.


Subject(s)
Ubiquitins/genetics , Giardia lamblia/metabolism , Ubiquitin/genetics , Ubiquitination , Ubiquitins/metabolism , Signal Transduction , Models, Molecular , Giardia lamblia/genetics , Ubiquitin/metabolism
7.
Article in Chinese | WPRIM | ID: wpr-828529

ABSTRACT

Cullin-RING E3 ligases (CRLs) are the major components of ubiquitin-proteasome system, responsible for ubiquitylation and subsequent degradation of thousands of cellular proteins. CRLs play vital roles in the regulation of multiple cellular processes, including cell cycle, cell apoptosis, DNA replication, signalling transduction among the others, and are frequently dysregulated in many human cancers. The discovery of specific neddylation inhibitors, represented by MLN4924, has validated CRLs as promising targets for anti-cancer therapies with a growing market. Recent studies have focused on the discovery of the CRLs inhibitors by a variety of approaches, including high through-put screen, virtual screen or structure-based drug design. The field is, however, still facing the major challenging, since CRLs are a large multi-unit protein family without typical active pockets to facilitate the drug design, and enzymatic activity is mainly dependent on undruggable protein-protein interactions and dynamic conformation changes. Up to now, most reported CRLs inhibitors are aiming at targeting the F-box family proteins (e.g., SKP2, β-TrCP and FBXW7), the substrate recognition subunit of SCF E3 ligases. Other studies reported few small molecule inhibitors targeting the UBE2M-DCN1 interaction, which specifically inhibits CRL3/CRL1 by blocking the cullin neddylation. On the other hand, several CRL activators have been reported, such as plant auxin and immunomodulatory imide drugs, thalidomide. Finally, proteolysis-targeting chimeras (PROTACs) has emerged as a new technology in the field of drug discovery, specifically targeting the undruggable protein-protein interaction. The technique connects the small molecule that selectively binds to a target protein to a CRL E3 via a chemical linker to trigger the degradation of target protein. The PROTAC has become a hotspot in the field of E3-ligase-based anti-cancer drug discovery.


Subject(s)
Humans , Antineoplastic Agents , Pharmacology , Therapeutic Uses , Drug Design , Drug Discovery , Enzyme Inhibitors , Pharmacology , Therapeutic Uses , Neoplasms , Ubiquitin-Protein Ligases , Metabolism , Ubiquitination
8.
Article in Chinese | WPRIM | ID: wpr-878682

ABSTRACT

Proteins exert their roles in life activities via post-translational modifications(PTMs),which include phosphorylation,acetylation,ubiquitination,glycosylation,and methylation.These modifications can change the functions of proteins and play key roles in a variety of diseases.Endometriosis is a common disease in women of childbearing age,although its molecular mechanisms remain unclear.Recent studies have shown that PTMs may be involved in the pathogenesis of endometriosis.Here we review the roles of PTMs in the occurrence and development of endometriosis and the potential medical treatments.


Subject(s)
Female , Humans , Acetylation , Endometriosis/pathology , Glycosylation , Phosphorylation , Protein Processing, Post-Translational , Ubiquitination
9.
Protein & Cell ; (12): 894-914, 2020.
Article in English | WPRIM | ID: wpr-880885

ABSTRACT

Tripartite motif (TRIM) family proteins are important effectors of innate immunity against viral infections. Here we identified TRIM35 as a regulator of TRAF3 activation. Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon (IFN) in response to viral infection. Trim35-deficient mice were more susceptible to influenza A virus (IAV) infection than were wild-type mice. TRIM35 promoted the RIG-I-mediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1. IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3. TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2, thereby antagonizing its suppression of TRAF3 activation. Our in vitro and in vivo findings thus reveal novel roles of TRIM35, through catalyzing Lys63- or Lys48-linked polyubiquitination, in RIG-I antiviral immunity and mechanism of defense against IAV infection.


Subject(s)
Animals , Dogs , Humans , Mice , A549 Cells , Apoptosis Regulatory Proteins/immunology , DEAD Box Protein 58/immunology , HEK293 Cells , Influenza A Virus, H1N1 Subtype/immunology , Madin Darby Canine Kidney Cells , Mice, Knockout , Orthomyxoviridae Infections/pathology , Proteolysis , Signal Transduction/immunology , THP-1 Cells , TNF Receptor-Associated Factor 3/immunology , Ubiquitination/immunology , Viral Proteins/immunology
10.
Article in English | WPRIM | ID: wpr-880485

ABSTRACT

Ubiquitination, an essential post-transcriptional modification (PTM), plays a vital role in nearly every biological process, including development and growth. Despite its functions in plant reproductive development, its targets in rice panicles remain unclear. In this study, we used proteome-wide profiling of lysine ubiquitination in rice (O. sativa ssp. indica) young panicles. We created the largest ubiquitinome dataset in rice to date, identifying 1638 lysine ubiquitination sites on 916 unique proteins. We detected three conserved ubiquitination motifs, noting that acidic glutamic acid (E) and aspartic acid (D) were most frequently present around ubiquitinated lysine. Enrichment analysis of Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of these ubiquitinated proteins revealed that ubiquitination plays an important role in fundamental cellular processes in rice young panicles. Interestingly, enrichment analysis of protein domains indicated that ubiquitination was enriched on a variety of receptor-like kinases and cytoplasmic tyrosine and serine-threonine kinases. Furthermore, we analyzed the crosstalk between ubiquitination, acetylation, and succinylation, and constructed a potential protein interaction network within our rice ubiquitinome. Moreover, we identified ubiquitinated proteins related to pollen and grain development, indicating that ubiquitination may play a critical role in the physiological functions in young panicles. Taken together, we reported the most comprehensive lysine ubiquitinome in rice so far, and used it to reveal the functional role of lysine ubiquitination in rice young panicles.


Subject(s)
Acetylation , Lysine/metabolism , Oryza/metabolism , Plant Proteins/metabolism , Protein Interaction Maps , Protein Processing, Post-Translational , Proteome/metabolism , Ubiquitin/metabolism , Ubiquitination
11.
Article in Chinese | WPRIM | ID: wpr-826373

ABSTRACT

Ubiquitin is a small molecule protein consisting of 76 amino acids,widely found in eukaryotic cells. The process by which ubiquitin binding to a specific protein is called ubiquitination. Deubiquitination is the reversed process of ubiquitination. Ubiquitination stimulates downstream signal,including complex assembly,protein conformation and activity changes,proteolysis,autophagy,guilt,chromatin remodeling,and DNA repair. More than 80% of eukaryotic protein degradation is mediated by the ubiquitination system,and ubiquitin-dependent proteolysis is an extremely complex process involving many biomolecular processes. By regulating protein homeostasis,ubiquitination can also regulate a variety of biological processes including cell cycle,cell proliferation,and apoptosis,which are closely related to tumorigenesis and progression. Many abnormalities of androgen receptor (AR) including AR gene amplification,mutation,shear mutation,and AR activity enhancement are closely related to prostate cancer progression. In particular,prostate cancer progression is regulated by the ubiquitination/deubiquitination processes. This article summarizes the recent research advances in the roles of ubiquitination/deubiquitination in AR abnormalities and prostate cancer.


Subject(s)
Humans , Male , Cell Line, Tumor , Prostatic Neoplasms , Metabolism , Pathology , Proteolysis , Receptors, Androgen , Metabolism , Ubiquitination
12.
Article in Chinese | WPRIM | ID: wpr-813009

ABSTRACT

To investigate the effects of thanatos-associated protein 11 (THAP11) on the proliferation and apoptosis of esophageal cancer cell and the underlying mechanism.
 Methods: Expression of THAP11 in human esophageal epithelial cells (Het-1A) and esophageal cancer cells (Eca109, TE-1, Ec 9706) were detected by Western blotting. Esophageal cancer TE-1 cells were divided into 3 groups: a normal control (NC) group, a negative control (LV-NC) group and a THAP11 (LV-THAP11) group. Then the cell proliferation were detected by MTT assay, cell apoptosis were detected by flow cytometry, caspase-3 and caspase-9 levels were detected by caspases kits. Ubiquitination of p53 was determined in esophageal cancer TE-1 cells.
 Results: Expression of THAP11 was reduced in esophageal cancer cells compared with human esophageal epithelial cells (P<0.05). After transfection with LV-THAP11 in TE-1 cells, cell viability was reduced (P<0.05), while apoptosis rate and caspase-3 and caspase-9 levels were increased (P<0.05), indicating that THAP11 inhibited growth of esophageal cancer cells. In addition, the THAP11 increased the levels of p53 (P<0.05) and inhibited the ubiquitination of p53 regulated by MDM2. 
 Conclusion: THAP11 may inhibit the proliferation of esophageal cancer cells by inhibiting ubiquitination of p53.


Subject(s)
Humans , Apoptosis , Cell Line, Tumor , Cell Proliferation , Esophageal Neoplasms , Repressor Proteins , Metabolism , Tumor Suppressor Protein p53 , Ubiquitination
13.
Article in Chinese | WPRIM | ID: wpr-774306

ABSTRACT

OBJECTIVE@#To explore the the effects of ubiquitin-proteasome system (UPS) on BCL6 protein level,proliferation and apoptosis of cell imatinib(IM)-resistant K562/G01 cells.@*METHODS@#Western blot was used to detect the expression of BCL6 in K562/G01 cells before and after treatment with protease inhibitor MG-132.The RT-PCR and Western blot respectively were used to detect the mRNA and protein expression levels of BCL6 and USP2 in K562/G01 cells treated with or without ML364 (a ubiquitin-specific protease USP2 inhibitor). The effects of IM alone or in combination with ML364 on proliferation and apoptosis of K562/G01 were analysed by CCK-8 method and flow cytometry.@*RESULTS@#After treatment with protease inhibitor MG132, the BCL6 protein level of K562/G01 significantly increased (P<0.05). The mRNA and protein expression level of ubiquitin-specific protease USP2 in K562/G01 cell line was higher than that in K562 cell line (P<0.05). After treatment of K562/G01 with USP2 protease inhibitor ML364, the expression levels of USP2 and BCL6 proteins were down-regulated simultaneously (P<0.05) . After combination of ML364 and IM, both the proliferation inhibitory rate and the apoptosis rate of K562/G01 cells significantly increased(P<0.05).@*CONCLUSION@#ML364 decreases the BCL6 protein stability in K562/G01 by inhibiting the USP2-mediated deubiquitination, and down-regulate the BCL6 protein experssion, thereby increases the sensitivity of drug-resistant cells to IM.


Subject(s)
Humans , Apoptosis , Cell Proliferation , Imatinib Mesylate , K562 Cells , Proto-Oncogene Proteins c-bcl-6 , Metabolism , Ubiquitination
14.
Immune Network ; : e32-2019.
Article in English | WPRIM | ID: wpr-764028

ABSTRACT

Pellino-1 is a ubiquitin (Ub) E3 ligase that plays a role in M1, but not M2a polarization of macrophages. However, it is unknown whether Pellino-1 regulates IL-10-mediated M2c polarization of macrophages. Here, we found that Pellino-1 attenuated tumor growth by inhibiting M2c polarization of macrophages. Upon IL-10 stimulation, Pellino-1-deificient bone marrow-derived macrophages (BMDMs) showed higher expression of M2c markers, but not M2a, and M2b markers than wild-type (WT) BMDMs, indicating that Pellino-1 inhibits M2c polarization of macrophages. Pellino-1-deficient BMDMs exhibited a defect in mitochondria respiration, but enhancement of glycolysis during M2c polarization. During M2c polarization of macrophages, Pellino-1 increased STAT1 phosphorylation via K63-linked ubiquitination of IL-1 receptor associated kinase 1 (IRAK1). Furthermore, Lysm-CrePellino-1(fl/fl) mice showed enhancement of tumor growth via regulating M2c polarization of tumor-associated macrophages. These results demonstrate that Pellino-1 inhibits IL-10-induced M2c macrophage polarization via K63-linked ubiquitination of IRAK1 and activation of STAT1, thereby inhibiting tumor growth in vivo.


Subject(s)
Animals , Mice , Glycolysis , Interleukin-1 , Interleukin-10 , Macrophages , Mitochondria , Phosphorylation , Phosphotransferases , Respiration , Ubiquitin , Ubiquitin-Protein Ligases , Ubiquitination
15.
Immune Network ; : e16-2019.
Article in English | WPRIM | ID: wpr-764015

ABSTRACT

Sequestosome 1 (SQSTM1, p62), a ubiquitin binding protein, plays a role in cell signaling, oxidative stress, and autophagy. However, its functional role in inflammatory signaling is controversial. Recent studies have shown that p62 is negatively implicated in inflammatory responses. But, the precise molecular mechanisms by which p62 regulates inflammatory responses remain unclear. In this study, we report on a new regulatory role for p62 in TLR4-mediated signaling. p62 overexpression led to the suppression of NF-κB activation and the production of pro-inflammatory cytokines, TNF-α, IL-6, and IL-1β in response to TLR4 stimulation. In contrast, p62(−/−) mouse embryonic fibroblast (MEF) cells exhibited marked enhancement of NF-κB activation and production of pro-inflammatory cytokines by TLR4 stimulation, compared to p62(+/+) MEF cells. Additionally, the TLR4-induced activation of signal transduction was significantly augmented in p62(−/−) MEF cells, indicating that p62 was negatively implicated in TLR4-mediated signaling. Biochemical studies revealed that p62 interacted with the internal domain of evolutionarily conserved signaling intermediate in Toll pathways (ECSIT), which is critical for associating with the TNF receptor associated factor 6 (TRAF6)-ECSIT complex to activate NF-κB in TLR4 signaling. Interestingly, p62-ECSIT interaction inhibited the interaction between TRAF6 and ECSIT and attenuated the ubiquitination of ECSIT. Furthermore, upon LPS challenge, the mortality of p62(−/−) (p62-knockout) mice was markedly enhanced compared to p62(+/+) (p62 wild-type) mice. Taken together, our data demonstrate that p62 negatively regulated TLR4 signaling via functional regulation of the TRAF6-ECSIT complex.


Subject(s)
Animals , Mice , Autophagy , Carrier Proteins , Cytokines , Fibroblasts , Interleukin-6 , Mortality , Oxidative Stress , Signal Transduction , TNF Receptor-Associated Factor 6 , Toll-Like Receptor 4 , Ubiquitin , Ubiquitination
16.
Braz. j. med. biol. res ; 52(5): e8412, 2019. graf
Article in English | LILACS | ID: biblio-1001528

ABSTRACT

Multiple myeloma (MM) is a malignant neoplasm of plasma, and exhibits several harmful effects including osteolytic injuries, hypercalcemia, and immune dysfunction. Many patients with MM succumb to the underlying malignancy. An S-phase kinase-related protein 2 (Skp2) inhibitor, designated SKPin C1, has been developed and confirmed to have an inhibitory effect on metastatic melanoma cells. This study aimed to determine the effect of SKPin C1 on MM. Normal B lymphocytes, THP-1 cells, and MM U266 and RPMI 8226 cells were exposed to various dosages of SKPin C1 for 48 h. Cell proliferation was determined by MTT, EdU staining, and cell cycle assays. Western blot assays were performed to assess intracellular protein levels of Skp2, p27, and cleaved caspase-3. The amount of ubiquitin attached to p27 was determined using an immunoprecipitation assay. The viability of U266 and RPMI 8226 cells was significantly inhibited by 10 μM SKPin C1 and the inhibitory effect was enhanced with increasing doses of SKPin C1. In contrast, 50 μM SKPin C1 only marginally decreased viability of normal B lymphocytes in 12 h. Skp2 and p27 expression in U266 and RPMI 8226 cells was higher and lower, respectively, than that in the normal B lymphocytes. Treatment with SKPin C1 or Skp2 knockdown increased p27 protein levels in U266 and RPMI 8226 cells by preventing p27 from being ubiquitinated, which slowed the cell cycle, inhibited cell proliferation, and triggered apoptosis. Therefore, this study suggested SKPin C1 as a potent inhibitor against aberrant proliferation and immortalization of MM.


Subject(s)
Humans , Apoptosis , S-Phase Kinase-Associated Proteins/metabolism , Cell Proliferation/physiology , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Multiple Myeloma/metabolism , Cell Cycle , S-Phase Kinase-Associated Proteins/antagonists & inhibitors , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p27/pharmacology , Ubiquitination/physiology , Ubiquitinated Proteins/metabolism , Multiple Myeloma/physiopathology
17.
Braz. j. med. biol. res ; 52(9): e8525, 2019. tab, graf
Article in English | LILACS | ID: biblio-1011614

ABSTRACT

Many compounds of ginsenosides show anti-inflammatory properties. However, their anti-inflammatory effects in intervertebral chondrocytes in the presence of inflammatory factors have never been shown. Increased levels of pro-inflammatory cytokines are generally associated with the degradation and death of chondrocytes; therefore, finding an effective and nontoxic substance that attenuates the inflammation is worthwhile. In this study, chondrocytes were isolated from the nucleus pulposus tissues, and the cells were treated with ginsenoside compounds and IL-1β, alone and in combination. Cell viability and death rate were assessed by CCK-8 and flow cytometry methods, respectively. PCR, western blot, and immunoprecipitation assays were performed to determine the mRNA and protein expression, and the interactions between proteins, respectively. Monomeric component of ginsenoside Rd had no toxicity at the tested range of concentrations. Furthermore, Rd suppressed the inflammatory response of chondrocytes to interleukin (IL)-1β by suppressing the increase in IL-1β, tumor necrosis factor (TNF)-α, IL-6, COX-2, and inducible nitric oxide synthase (iNOS) expression, and retarding IL-1β-induced degradation of chondrocytes by improving cell proliferation characteristics and expression of aggrecan and COL2A1. These protective effects of Rd were associated with ubiquitination of IL-1 receptor accessory protein (IL1RAP), blocking the stimulation of IL-1β to NF-κB. Bioinformatics analysis showed that NEDD4, CBL, CBLB, CBLC, and ITCH most likely target IL1RAP. Rd increased intracellular ITCH level and the amount of ITCH attaching to IL1RAP. Thus, IL1RAP ubiquitination promoted by Rd is likely to occur by up-regulation of ITCH. In summary, Rd inhibited IL-1β-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Chondrocytes/drug effects , Ginsenosides/pharmacology , Interleukin-1beta/drug effects , Interleukin-1 Receptor Accessory Protein/metabolism , Intervertebral Disc Degeneration/metabolism , Dinoprostone/metabolism , Cell Survival/drug effects , Tumor Necrosis Factor-alpha/metabolism , Low Back Pain/metabolism , Nitric Oxide Synthase/metabolism , Chondrocytes/cytology , Chondrocytes/metabolism , Ginsenosides/metabolism , Cyclooxygenase 2/metabolism , Aggrecans/metabolism , Interleukin-1beta/metabolism , Ubiquitination , Nucleus Pulposus/cytology , Nucleus Pulposus/drug effects , Nucleus Pulposus/metabolism , Inflammation/metabolism
18.
Braz. j. med. biol. res ; 51(12): e7437, 2018. tab, graf
Article in English | LILACS | ID: biblio-974252

ABSTRACT

Pulmonary arterial hypertension (PAH), characterized by localized increased arterial blood pressure in the lungs, is a slow developing long-term disease that can be fatal. PAH is characterized by inflammation, vascular tone imbalance, pathological pulmonary vascular remodeling, and right-sided heart failure. Current treatments for PAH are palliative and development of new therapies is necessary. Recent and relevant studies have demonstrated that epigenetic processes may exert key influences on the pathogenesis of PAH and may be promising therapeutic targets in the prevention and/or cure of this condition. The aim of the present mini-review is to summarize the occurrence of epigenetic-based mechanisms in the context of PAH physiopathology, focusing on the roles of DNA methylation, histone post-translational modifications and non-coding RNAs. We also discuss the potential of epigenetic-based therapies for PAH.


Subject(s)
Humans , DNA Methylation/genetics , RNA, Untranslated/genetics , Epigenesis, Genetic/genetics , Histone Code/genetics , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/genetics , Pulmonary Artery/pathology , Down-Regulation/genetics , Up-Regulation/genetics , Ubiquitination/genetics , Molecular Targeted Therapy , Hypertension, Pulmonary/therapy
19.
Article in English | WPRIM | ID: wpr-740116

ABSTRACT

Imbalance of protein homeostasis (proteostasis) is known to cause cellular malfunction, cell death, and diseases. Elaborate regulation of protein synthesis and degradation is one of the important processes in maintaining normal cellular functions. Protein degradation pathways in eukaryotes are largely divided into proteasome-mediated degradation and lysosome-mediated degradation. Proteasome is a multisubunit complex that selectively degrades 80% to 90% of cellular proteins. Proteasome-mediated degradation can be divided into 26S proteasome (20S proteasome + 19S regulatory particle) and free 20S proteasome degradation. In 1980, it was discovered that during ubiquitination process, wherein ubiquitin binds to a substrate protein in an ATP-dependent manner, ubiquitin acts as a degrading signal to degrade the substrate protein via proteasome. Conversely, 20S proteasome degrades the substrate protein without using ATP or ubiquitin because it recognizes the oxidized and structurally modified hydrophobic patch of the substrate protein. To date, most studies have focused on protein degradation via 26S proteasome. This review describes the 26S/20S proteasomal pathway of protein degradation and discusses the potential of proteasome as therapeutic targets for cancer treatment as well as against diseases caused by abnormalities in the proteolytic system.


Subject(s)
Adenosine Triphosphate , Cell Death , Eukaryota , Homeostasis , Oxidative Stress , Proteasome Endopeptidase Complex , Proteolysis , Ubiquitin , Ubiquitination
20.
Article in English | WPRIM | ID: wpr-740115

ABSTRACT

TGF-β signaling plays a tumor suppressive role in normal and premalignant cells but promotes tumor progression during the late stages of tumor development. The TGF-β signaling pathway is tightly regulated at various levels, including transcriptional and post-translational mechanisms. Ubiquitination of signaling components, such as receptors and Smad proteins is one of the key regulatory mechanisms of TGF-β signaling. Tripartite motif (TRIM) family of proteins is a highly conserved group of E3 ubiquitin ligase proteins that have been implicated in a variety of cellular functions, including cell growth, differentiation, immune response, and carcinogenesis. Recent emerging studies have shown that some TRIM family proteins function as important regulators in tumor initiation and progression. This review summarizes current knowledge of TRIM family proteins regulating the TGF-β signaling pathway with relevance to cancer.


Subject(s)
Humans , Carcinogenesis , Smad Proteins , Transforming Growth Factor beta , Ubiquitin , Ubiquitin-Protein Ligases , Ubiquitination
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