-
Journal of Gastroenterology Jun 2024Accumulating evidence has shown that the NOD-like receptor protein 3 (NLRP3) inflammasome plays a crucial role in the inflammatory cascades involved in the development...
BACKGROUND
Accumulating evidence has shown that the NOD-like receptor protein 3 (NLRP3) inflammasome plays a crucial role in the inflammatory cascades involved in the development of acute pancreatitis (AP). However, the specific agonist responsible for activating the NLRP3 inflammasome in this process has not yet been identified. The purpose of this study is to clarify whether heparan sulfate (HS) works as an NLRP3 inflammasome activator to evoke inflammatory cascades in the progression of AP.
METHODS
Two experimental mouse models of AP were utilized to investigate the pro-inflammatory activity of HS in the development of AP by measuring the secretion of inflammatory cytokines and the neutrophil infiltration in pancreatic tissue. The ability of HS to activate the NLRP3 inflammasome was evaluated both in vitro and in vivo. The nuclear factor kappa B (NF-κB)-mediated expression of NLRP3 inflammasome components in response to HS treatment was determined to decipher the role of HS in transcriptional priming of NLRP3 inflammasome. Furthermore, HS-triggered deubiquitination of NLRP3 was analyzed to reveal the promoting effect of HS on the NLRP3 inflammasome priming via a non-transcriptional pathway.
RESULTS
High plasma level of HS was observed with a positive correlation to that of inflammatory cytokines in AP mice. Administration of HS to mice resulted in an exacerbated inflammatory profile, while reducing HS production by an inhibitor of heparanase significantly attenuated inflammatory response. Pharmacological inhibition or genetic deletion of NLRP3 substantially suppressed the HS-stimulated elevation of IL-1β levels in AP mice. The in vitro data demonstrated that HS primarily serves as a priming signal for the activation of the NLRP3 inflammasome. HS possesses the ability to increase the transcriptional activity of NF-κB and TLR4/NF-κB-driven transcriptional pathway is employed for NLRP3 inflammasome priming. Moreover, HS-induced deubiquitination of NLRP3 is another pathway responsible for non-transcriptional priming of NLRP3 inflammasome.
CONCLUSIONS
Our current work has unveiled HS as a new activator of the NLRP3 inflammasome responsible for the secondary inflammatory cascades during the development of AP, highlighting the HS-NLRP3 pathway as a potential target for future preventive and therapeutic approaches of AP.
PubMed: 38864913
DOI: 10.1007/s00535-024-02127-6 -
Diagnostic Pathology Jun 2024Osteosarcoma is a bone tumor that is characterized by high malignancy and a high mortality rate, and that originates from primitive osteoblastic mesenchymal cells and is...
BACKGROUND
Osteosarcoma is a bone tumor that is characterized by high malignancy and a high mortality rate, and that originates from primitive osteoblastic mesenchymal cells and is most common in rapidly growing long bones. PSMD14, also known as RPN11 or POH1, is a member of the JAMM isopeptidase family, which is able to remove the substrate protein ubiquitination label, thereby regulating the stability and function of the substrate protein. In this study, we explored the expression and potential biological significance of the PSMD14 deubiquitinating enzyme in osteosarcoma.
METHODS
Immunohistochemical methods were used to detect the expression of PSMD14 in biopsies of 91 osteosarcoma patients, and the specimens were classified into high and low PSMD14 expression groups. The correlation between PSMD14 expression and clinical indicators and prognosis was compared.SiRNA was used to downregulate PSMD14 in two osteosarcoma cell lines (HOS and SJSA-1), and the effects of downregulation of PSMD14 on the viability, proliferation, and invasion ability of osteosarcoma cells were analyzed.
RESULTS
We identified significant differences in recurrence, metastasis, and survival time of the osteosarcoma patients on the basis of PSMD14 expression. High expression of PSMD14 in osteosarcoma patients was associated with a low survival rate and high risk of metastasis and recurrence. Down-regulation of PSMD14 inhibited the viability, proliferation, and invasiveness of osteosarcoma cell lines.
CONCLUSIONS
PSMD14 may be a new prognostic marker and therapeutic target for osteosarcoma.
Topics: Osteosarcoma; Humans; Bone Neoplasms; Male; Biomarkers, Tumor; Female; Prognosis; Cell Line, Tumor; Adult; Cell Proliferation; Proteasome Endopeptidase Complex; Adolescent; Young Adult; Middle Aged; Neoplasm Invasiveness; Trans-Activators
PubMed: 38863002
DOI: 10.1186/s13000-024-01489-y -
BioRxiv : the Preprint Server For... May 2024The ubiquitin-like protein ISG15 (interferon-stimulated gene 15) regulates the host response to bacterial and viral infections through its conjugation to proteins...
The ubiquitin-like protein ISG15 (interferon-stimulated gene 15) regulates the host response to bacterial and viral infections through its conjugation to proteins (ISGylation) following interferon production. ISGylation is antagonized by the highly specific cysteine protease USP18, which is the major deISGylating enzyme. However, mechanisms underlying USP18's extraordinary specificity towards ISG15 remains elusive. Here, we show that USP18 interacts with its paralog USP41, whose catalytic domain shares 97% identity with USP18. However, USP41 does not act as a deISGylase, which led us to perform a comparative analysis to decipher the basis for this difference, revealing molecular determinants of USP18's specificity towards ISG15. We found that USP18 C-terminus, as well as a conserved Leucine at position 198, are essential for its enzymatic activity and likely act as functional surfaces based on AlphaFold predictions. Finally, we propose that USP41 antagonizes conjugation of the understudied ubiquitin-like protein FAT10 (HLA-F adjacent transcript 10) from substrates in a catalytic-independent manner. Altogether, our results offer new insights into USP18's specificity towards ISG15, while identifying USP41 as a negative regulator of FAT10 conjugation.
PubMed: 38853827
DOI: 10.1101/2024.05.28.596309 -
Cancer Letters Aug 2024B7-H4 is an immune checkpoint crucial for inhibiting CD8 T-cell activity. A clinical trial is underway to investigate B7-H4 as a potential immunotherapeutic agent....
B7-H4 is an immune checkpoint crucial for inhibiting CD8 T-cell activity. A clinical trial is underway to investigate B7-H4 as a potential immunotherapeutic agent. However, the regulatory mechanism of B7-H4 degradation via the ubiquitin-proteasome pathway (UPP) remains poorly understood. In this study, we discovered that proteasome inhibitors effectively increased B7-H4 expression, while EGFR-activating mutants promoted B7-H4 expression through the UPP. We screened B7-H4 binding proteins by co-immunoprecipitation and mass spectrometry and found that USP2a acted as a deubiquitinase of B7-H4 by removing K48- and K63-linked ubiquitin chains from B7-H4, leading to a reduction in B7-H4 degradation. EGFR mutants enhanced B7-H4 stability by upregulating USP2a expression. We further investigated the role of USP2a in tumor growth in vivo. Depletion of USP2a in L858R/LLC cells inhibited tumor cell proliferation, consequently suppressing tumor growth in immune-deficient nude mice by destabilizing downstream molecules such as Cyclin D1. In an immune-competent C57BL/6 mouse tumor model, USP2a abrogation facilitated infiltration of CD95CD8 effector T cells and hindered infiltration of Tim-3+CD8 and LAG-3+CD8 exhausted T cells by destabilizing B7-H4. Clinical lung adenocarcinoma samples showed a significant correlation between B7-H4 abundance and USP2a expression, indicating the contribution of the EGFR/USP2a/B7-H4 axis to tumor immunosuppression. In summary, this study elucidates the dual effects of USP2a in tumor growth by stabilizing Cyclin D1, promoting tumor cell proliferation, and stabilizing B7-H4, contributing to tumor immunosuppression. Therefore, USP2a represents a potential target for tumor therapy.
Topics: Animals; Humans; ErbB Receptors; Ubiquitin Thiolesterase; Mice; V-Set Domain-Containing T-Cell Activation Inhibitor 1; Lung Neoplasms; Adenocarcinoma of Lung; Cell Line, Tumor; Mice, Nude; Cell Proliferation; Mutation; Mice, Inbred C57BL; CD8-Positive T-Lymphocytes; Proteasome Endopeptidase Complex
PubMed: 38849009
DOI: 10.1016/j.canlet.2024.217020 -
Cancer Science Jun 2024Ubiquitin-specific peptidase 15 (USP15), a critical deubiquitinating enzyme, has been demonstrated to improve substrate stabilization by hydrolyzing the bond between the...
Ubiquitin-specific peptidase 15 (USP15), a critical deubiquitinating enzyme, has been demonstrated to improve substrate stabilization by hydrolyzing the bond between the substrate and ubiquitin, and is implicated in multiple carcinogenic processes. Prompted by the information cited from The Cancer Genome Atlas (TCGA) database and the Cancer Proteogenomic Data Analysis Site (cProSite), USP15 is selectively overexpressed in clear cell renal cell carcinoma (ccRCC) samples. We aimed to investigate the function of USP15 on ccRCC malignant features, which was emphasized in its deubiquitination of SHC adaptor protein 1 (SHC1). The overexpression of USP15 promoted the capacity of proliferation, migration, and invasion in ccRCC CAKI1 and 769-P cells, and these malignant biological properties were diminished by USP15 deletion in 786-O cells. USP15 accelerated tumor growth and lung metastasis in vivo. In addition, deubiquitinase USP15 was further identified as a new protector for SHC1 from degradation by the ubiquitination pathway, the post-translational modification. In sequence, transcription factor activating enhancer binding protein 4 (TFAP4) was shown to be partly responsible for USP15 expression at the level of transcription, as manifested by the chromatin immunoprecipitation and pull-down assay. Based on the in vitro and in vivo data, we postulate that USP15 regulated by TFAP4 transcriptionally deteriorates ccRCC malignant biological properties via stabilizing SHC1 by deubiquitination.
PubMed: 38847328
DOI: 10.1111/cas.16237 -
Scientific Reports Jun 2024The proteasome-associated deubiquitinase USP14 is a potential drug target. Using an inducible USP14 knockout system in colon cancer cells, we found that USP14 depletion...
The proteasome-associated deubiquitinase USP14 is a potential drug target. Using an inducible USP14 knockout system in colon cancer cells, we found that USP14 depletion impedes cellular proliferation, induces cell cycle arrest, and leads to a senescence-like phenotype. Transcriptomic analysis revealed altered gene expression related to cell division and cellular differentiation. USP14 knockout cells also exhibited changes in morphology, actin distribution, and expression of actin cytoskeletal components. Increased ubiquitin turnover was observed, offset by upregulation of polyubiquitin genes UBB and UBC. Pharmacological inhibition of USP14 with IU1 increased ubiquitin turnover but did not affect cellular growth or morphology. BioGRID data identified USP14 interactors linked to actin cytoskeleton remodeling, DNA damage repair, mRNA splicing, and translation. In conclusion, USP14 loss in colon cancer cells induces a transient quiescent cancer phenotype not replicated by pharmacologic inhibition of its deubiquitinating activity.
Topics: Humans; Cellular Senescence; Colorectal Neoplasms; Cell Proliferation; Ubiquitin Thiolesterase; Cell Line, Tumor; Phenotype; Proteasome Endopeptidase Complex; Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Ubiquitin
PubMed: 38844605
DOI: 10.1038/s41598-024-63791-5 -
Identification of COP9 signalosome (CSN) subunits and antiviral function analysis of CSN5 in shrimp.Fish & Shellfish Immunology Jun 2024The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) typically composing of eight subunits (CSN1-8) mediates the process of deneddylation and deubiquitination....
The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) typically composing of eight subunits (CSN1-8) mediates the process of deneddylation and deubiquitination. The fifth subunit of COP9 signalosome, CSN5, has special characteristics compared with the other seven subunits, and plays vital roles in the deneddylation activity and diverse cellular processes. However, the role of CSN5 in antiviral immunity is not clear. In this study, we identified 8 subunits (CSN1-8) of COP9 signalosome in shrimp Marsupenaeus japonicus. CSN1-6 were existed in all tested tissues, but CSN7-CSN8 were not detected in hepatopancreas. After WSSV challenged, the expression level of Csn1 to Csn4, and Csn6 to Csn8 were highly decreased, but the expression level of Csn5 was conspicuously increased in shrimp challenged by white spot syndrome virus (WSSV). The CSN5 was recombinantly expressed in Escherichia coli and its polyclonal antibody was prepared. The expression level of CSN5 was conspicuously increased at RNA and protein levels in the shrimp challenged by WSSV. After knockdown of Csn5 by RNA interference, the WSSV replication was obviously increased in shrimp. When injected the recombinant protein of CSN5 with the membrane penetrating peptide into shrimp, WSSV replication was inhibited and the survival rate of shrimp was significantly improved compared with control. We further analyzed the expression of antimicrobial peptides (AMPs) in Csn5-RNAi shrimp, and the results showed that the expression of several AMPs was declined significantly. These results indicate that CSN5 inhibits replication of WSSV via regulating expression of AMPs in shrimp, and the recombinant CSN5 might be used in shrimp aquaculture for the white spot syndrome disease control.
PubMed: 38844185
DOI: 10.1016/j.fsi.2024.109679 -
Biochimica Et Biophysica Acta.... Jun 2024Hepatocellular carcinoma (HCC), the leading cause of cancer-related deaths worldwide, is characterised by rapid growth and marked invasiveness. Accumulating evidence...
Hepatocellular carcinoma (HCC), the leading cause of cancer-related deaths worldwide, is characterised by rapid growth and marked invasiveness. Accumulating evidence suggests that deubiquitinases play a pivotal role in HCC growth and metastasis. However, the expression of the deubiquitinase FAM188B and its biological functions in HCC remain unknown. The aim of our study was to investigate the potential role of FAM188B in HCC. The expression of FAM188B was significantly upregulated in liver cancer cells compared to normal liver cells, both at the transcriptional and translational levels. Similarly, FAM188B expression was higher in liver cancer tissues than in normal liver tissues. Bioinformatic analysis revealed that high FAM188B expression was associated with poor prognosis in patients with HCC. We further demonstrated that FAM188B knockdown inhibited cell proliferation, epithelial-mesenchymal transition, migration and invasion both in vitro and in vivo. Mechanistically, FAM188B knockdown significantly inhibited the hnRNPA1/PKM2 pathway in HCC cells. FAM188B may inhibit ubiquitin-mediated degradation of hnRNPA1 through deubiquitination. Notably, we observed that the inhibitory effects of FAM188B knockdown on HCC cell proliferation, migration and invasion were reversed when hnRNPA1 expression was restored. In conclusion, FAM188B promotes HCC progression by enhancing the deubiquitination of hnRNPA1 and subsequently activating the hnRNPA1/PKM2 pathway. Therefore, targeting FAM188B is a potential strategy for HCC therapy.
PubMed: 38844182
DOI: 10.1016/j.bbamcr.2024.119773 -
Cancer Immunology, Immunotherapy : CII Jun 2024This study investigates the role of USP47, a deubiquitinating enzyme, in the tumor microenvironment and its impact on antitumor immune responses. Analysis of TCGA...
This study investigates the role of USP47, a deubiquitinating enzyme, in the tumor microenvironment and its impact on antitumor immune responses. Analysis of TCGA database revealed distinct expression patterns of USP47 in various tumor tissues and normal tissues. Prostate adenocarcinoma showed significant downregulation of USP47 compared to normal tissue. Correlation analysis demonstrated a positive association between USP47 expression levels and infiltrating CD8 T cells, neutrophils, and macrophages, while showing a negative correlation with NKT cells. Furthermore, using Usp47 knockout mice, we observed a slower tumor growth rate and reduced tumor burden. The absence of USP47 led to increased infiltration of immune cells, including neutrophils, macrophages, NK cells, NKT cells, and T cells. Additionally, USP47 deficiency resulted in enhanced activation of cytotoxic T lymphocytes (CTLs) and altered T cell subsets within the tumor microenvironment. These findings suggest that USP47 plays a critical role in modulating the tumor microenvironment and promoting antitumor immune responses, highlighting its potential as a therapeutic target in prostate cancer.
Topics: Animals; Male; Prostatic Neoplasms; Mice; Tumor Microenvironment; Mice, Knockout; Lymphocytes, Tumor-Infiltrating; Humans; Mice, Inbred C57BL; Cell Line, Tumor
PubMed: 38832955
DOI: 10.1007/s00262-024-03730-5 -
Cellular and Molecular Life Sciences :... Jun 2024The high degree of intratumoral genomic heterogeneity is a major obstacle for glioblastoma (GBM) tumors, one of the most lethal human malignancies, and is thought to...
BACKGROUND
The high degree of intratumoral genomic heterogeneity is a major obstacle for glioblastoma (GBM) tumors, one of the most lethal human malignancies, and is thought to influence conventional therapeutic outcomes negatively. The proneural-to-mesenchymal transition (PMT) of glioma stem cells (GSCs) confers resistance to radiation therapy in glioblastoma patients. POLD4 is associated with cancer progression, while the mechanisms underlying PMT and tumor radiation resistance have remained elusive.
METHOD
Expression and prognosis of the POLD family were analyzed in TCGA, the Chinese Glioma Genome Atlas (CGGA) and GEO datasets. Tumorsphere formation and in vitro limiting dilution assay were performed to investigate the effect of UCHL3-POLD4 on GSC self-renewal. Apoptosis, TUNEL, cell cycle phase distribution, modification of the Single Cell Gel Electrophoresis (Comet), γ-H2AX immunofluorescence, and colony formation assays were conducted to evaluate the influence of UCHL3-POLD4 on GSC in ionizing radiation. Coimmunoprecipitation and GST pull-down assays were performed to identify POLD4 protein interactors. In vivo, intracranial xenograft mouse models were used to investigate the molecular effect of UCHL3, POLD4 or TCID on GCS.
RESULT
We determined that POLD4 was considerably upregulated in MES-GSCs and was associated with a meagre prognosis. Ubiquitin carboxyl terminal hydrolase L3 (UCHL3), a DUB enzyme in the UCH protease family, is a bona fide deubiquitinase of POLD4 in GSCs. UCHL3 interacted with, depolyubiquitinated, and stabilized POLD4. Both in vitro and in vivo assays indicated that targeted depletion of the UCHL3-POLD4 axis reduced GSC self-renewal and tumorigenic capacity and resistance to IR treatment by impairing homologous recombination (HR) and nonhomologous end joining (NHEJ). Additionally, we proved that the UCHL3 inhibitor TCID induced POLD4 degradation and can significantly enhance the therapeutic effect of IR in a gsc-derived in situ xenograft model.
CONCLUSION
These findings reveal a new signaling axis for GSC PMT regulation and highlight UCHL3-POLD4 as a potential therapeutic target in GBM. TCID, targeted for reducing the deubiquitinase activity of UCHL3, exhibited significant synergy against MES GSCs in combination with radiation.
Topics: Humans; Ubiquitin Thiolesterase; Radiation Tolerance; Neoplastic Stem Cells; Animals; Mice; Cell Line, Tumor; Glioma; Apoptosis; Ubiquitination; Brain Neoplasms; Mice, Nude; Phenotype; Gene Expression Regulation, Neoplastic; Prognosis
PubMed: 38829550
DOI: 10.1007/s00018-024-05265-5