PSMB1 Negatively Regulates the Innate Antiviral Immunity by Facilitating Degradation of IKK-ε

Proteomic Mendelian randomization to identify protein biomarkers of telomere length

Shortening of telomere length (TL) is correlated with many age-related disorders and is a hallmark of biological aging. This study used proteome-wide Mendelian randomization to identify the protein biomarkers associated with telomere length. Protein quantitative trait loci (pQTL) were derived from two studies, the deCODE Health study (4907 plasma proteins) and the UK Biobank Pharma Proteomics Project (2923 plasma proteins). Summary data from genome-wide association studies (GWAS) for TL were obtained from the UK Biobank (472,174 cases) and GWAS Catalog (418,401 cases). The association between proteins and TL was further assessed using colocalization and summary data-based Mendelian randomization (SMR) analyses. The protein-protein network, druggability assessment, and phenome-wide MR were used to further evaluate the potential biological effects, druggability, and safety of the target proteins. Proteome-wide MR analysis identified 22 plasma proteins that were causally associated with telomere length. Five of these proteins (APOE, SPRED2, MAX, RALY, and PSMB1) had the highest evidence of association with TL and should be prioritized. This study revealed telomere length-related protein biomarkers, providing new insights into the development of new treatment targets for chronic diseases and anti-aging intervention strategies.

DLG1 promotes the antiviral innate immune response by inhibiting p62-mediated autophagic degradation of IKKε

IMPORTANCE

The type-I interferon (IFN-I) signaling pathway is the first line of antiviral innate immunity. It must be precisely regulated against virus-induced damage. The tightly regulated mechanisms of action of host genes in the antiviral innate immune signaling pathway are still worth studying. Here, we report a novel role of DLG1 in positively regulating the IκB kinase epsilon (IKKε)-mediated IFN-I signaling response against negative-stranded RNA virus replication, whereas the RNA virus inhibits the expression of DLG1 for immune escape. Importantly, the E3 ligase March2 interacts with and promotes K27-linked polyubiquitination of IKKε, and p62 is a cargo receptor that recognizes ubiquitinated IKKε for eventual autophagic degradation. Together, the current findings elucidate the role of DLG1 in the antiviral IFN-I signaling pathway and viral infection repression.

PSMB4 Degrades the Porcine Reproductive and Respiratory Syndrome Virus Nsp1α Protein via the Autolysosome Pathway and Induces the Production of Type I Interferon

Porcine reproductive and respiratory syndrome virus (PRRSV) causes respiratory disease in pigs of all ages and reproductive failure in sows, resulting in great economic losses to the swine industry. In this work, we identified the interaction between PSMB4 and PRRSV Nsp1α by yeast two-hybrid screening. The PSMB4-Nsp1α interaction was further confirmed by coimmunoprecipitation, glutathione S-transferase (GST) pulldown, and laser confocal experiments. The PCPα domain (amino acids 66 to 166) of Nsp1α and the C-terminal domain (amino acids 250 to 264) of PSMB4 were shown to be critical for the PSMB4-Nsp1α interaction. PSMB4 overexpression reduced PRRSV replication, whereas PSMB4 knockdown elicited opposing effects. Mechanistically, PSMB4 targeted K169 in Nsp1α for K63-linked ubiquitination and targeted Nsp1α for autolysosomal degradation by interacting with LC3 to enhance the activation of the lysosomal pathway. Meanwhile, we found that PSMB4 activated the NF-κB signaling pathway to produce type I interferons by downregulating the expression of IκBα and p-IκBα. In conclusion, our data revealed a new mechanism of PSMB4-mediated restriction of PRRSV replication, whereby PSMB4 was found to induce Nsp1α degradation and type I interferon expression, in order to impede the replication of PRRSV. IMPORTANCE In the swine industry, PRRSV is a continuous threat, and the current vaccines are not effective enough to block it. This study determined that PSMB4 plays an antiviral role against PRRSV. PSMB4 was found to interact with PRRSV Nsp1α, mediate K63-linked ubiquitination of Nsp1α at K169, and thus trigger its degradation via the lysosomal pathway. Additionally, PSMB4 activated the NF-κB signaling pathway to produce type I interferons by downregulating the expression of IκBα and p-IκBα. This study extends our understanding of the proteasome subunit PSMB4 against PRRSV replication and will contribute to the development of new antiviral strategies.

PSMB1 Inhibits the Replication of Porcine Reproductive and Respiratory Syndrome Virus by Recruiting NBR1 To Degrade Nonstructural Protein 12 by Autophagy

The nonstructural proteins (Nsps) of porcine reproductive and respiratory syndrome virus (PRRSV) play essential roles in virus replication-a multistep process that requires the participation of host factors. It is of great significance for the development of antiviral drugs to characterize the host proteins that interact with PRRSV Nsps and their functions in PRRSV replication. Here, we determined that proteasome subunit β type 1 (PSMB1) interacted with viral Nsp12 to inhibit PRRSV replication in target and permissive cells. PSMB1 could be downregulated by PRRSV infection through interaction with the transcription factor EBF1. Proteasome and autophagy inhibitor assays showed that PSMB1 was regulated by the autophagic pathway to degrade Nsp12. Cotransfection of PSMB1 and Nsp12 increased the level of intracellular autophagy; both molecules were colocated in lysosomes. We also found that the selective autophagy cargo receptor protein NBR1 and E3 ubiquitin ligase STUB1 interacted with PSMB1 and Nsp12, respectively, in the autophagic degradation of Nsp12. Furthermore, the degradation of Nsp12 by PSMB1 was mainly dependent on the ubiquitination of Nsp12 at lysine site 130. Our results indicate for the first time that PSMB1 is an anti-PRRSV host protein that inhibits the replication of PRRSV by degradation of Nsp12 through the selective autophagy pathway. IMPORTANCE PRRS is a major threat to the global pig industry and urgently requires an effective and sustainable control strategy. PRRSV Nsps have important roles in viral RNA synthesis, proteinase activity, induction of replication-associated membrane rearrangements, replicative endoribonuclease activity, determination of virulence, and regulation of host immune response. Research associated with PRRSV Nsps can provide vital guidance to modify the PRRSV genome through reverse genetics in the development of vaccines and diagnostics. The function of Nsp12, which generally plays essential roles in virus replication, remains unclear. We demonstrated that PSMB1 interacted with and degraded Nsp12 through an autophagic pathway to inhibit PRRSV replication. Our data confirmed a novel antiviral function of PSMB1 and allowed us to elaborate on the roles of Nsp12 in PRRSV pathogenesis. These findings suggest a valid and highly conserved candidate target for the development of novel therapies and more effective vaccines and demonstrate the complex cross talk between selective autophagy and PRRSV infection.

An ankylosing spondylitis risk variant alters osteoclast differentiation

OBJECTIVE

To explore whether the variants in non-MHC proteasome gene is associated with ankylosing spondylitis and explain the role of the variant in the disease.

METHODS

Case-control analysis to identify ankylosing spondylitis predisposition genes; dual-luciferase reporter assay, immunoblot analysis and osteoclastogenesis assays to detect the function of the positive variant. Affected individuals was diagnosed according to the modified New York Criteria by at least two experienced rheumatologists, and rechecked by another rheumatologist.

RESULTS

The study included 1037 AS patients and 1014 no rheumatic and arthritis disease controls. The main age of AS onset is between 16 and 35 years old. HLA-B27-positive subjects comprised 90.0% of patients. A nonsynonymous SNP rs12717 in proteasome gene PSMB1 significantly associated with ankylosing spondylitis. Individuals with CC genotype had a higher onset risk compared with those with GG/GC genotypes (OR = 1.89, p= 0.0047). We also discovered that PSMB1 regulates the receptor activator of nuclear factor-κB (RANK)/RANK ligand (RANKL) signalling pathway and the disease-associated variant PSMB1-Pro11 significantly inhibits RANKL-induced NF-κB pathway in osteoclast differentiation via the degradation of IKK-β compared with PSMB1-Ala11. RANKL induced osteoclast differentiation was significantly lower in primary monocyte osteoclast precursor from individuals with genotype PSMB131C/31C compared with individuals with genotype PSMB131G/31G.

CONCLUSIONS

These results reveal a novel understanding of the bone formation and reabsorbing imbalance in AS. The new bone formation phenotype can be attributed to the inhibition of osteoclast differentiation by a more functional PSMB1 gene.

Antigen Presentation Machinery Signature-Derived CALR Mediates Migration, Polarization of Macrophages in Glioma and Predicts Immunotherapy Response

Immunogenicity, influenced by tumor antigenicity and antigen presenting efficiency, critically determines the effectiveness of immune checkpoint inhibitors. The role of immunogenicity has not been fully elucidated in gliomas. In this study, a large-scale bioinformatics analysis was performed to analyze the prognostic value and predictive value of antigen presentation machinery (APM) signature in gliomas. ssGSEA algorithm was used for development of APM signature and LASSO regression analysis was used for construction of APM signature-based risk score. APM signature and risk score showed favorable performance in stratifying survival and predicting tumorigenic factors of glioma patients. APM signature and risk score were also associated with different genomic features in both training cohort TCGA and validating cohort CGGA. Furthermore, APM signature-based risk score was independently validated in three external cohorts and managed to predict immunotherapy response. A prognostic nomogram was constructed based on risk score. Risk score-derived CALR was found to mediate the invasion and polarization of macrophages based on the coculture of HMC3 and U251 cells. CALR could significantly predict immunotherapy response. In conclusion, APM signature and APM signature-based risk score could help promote the clinical management of gliomas.

Toll-like receptor 3 (TLR3) regulation mechanisms and roles in antiviral innate immune responses

Toll-like receptor 3 (TLR3) is a member of the TLR family, mediating the transcriptional induction of type I interferons (IFNs), proinflammatory cytokines, and chemokines, thereby collectively establishing an antiviral host response. Studies have shown that unlike other TLR family members, TLR3 is the only RNA sensor that is utterly dependent on the Toll-interleukin-1 receptor (TIR)‍-domain-containing adaptor-inducing IFN-‍β (TRIF). However, the details of how the TLR3-TRIF signaling pathway works in an antiviral response and how it is regulated are unclear. In this review, we focus on recent advances in understanding the antiviral mechanism of the TRIF pathway and describe the essential characteristics of TLR3 and its antiviral effects. Advancing our understanding of TLR3 may contribute to disease diagnosis and could foster the development of novel treatments for viral diseases.

Proteomic Signature of Host Response to SARS-CoV-2 Infection in the Nasopharynx

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has become a global health pandemic. COVID-19 severity ranges from an asymptomatic infection to a severe multiorgan disease. Although the inflammatory response has been implicated in the pathogenesis of COVID-19, the exact nature of dysregulation in signaling pathways has not yet been elucidated, underscoring the need for further molecular characterization of SARS-CoV-2 infection in humans. Here, we characterize the host response directly at the point of viral entry through analysis of nasopharyngeal swabs. Multiplexed high-resolution MS-based proteomic analysis of confirmed COVID-19 cases and negative controls identified 7582 proteins and revealed significant upregulation of interferon-mediated antiviral signaling in addition to multiple other proteins that are not encoded by interferon-stimulated genes or well characterized during viral infections. Downregulation of several proteasomal subunits, E3 ubiquitin ligases, and components of protein synthesis machinery was significant upon SARS-CoV-2 infection. Targeted proteomics to measure abundance levels of MX1, ISG15, STAT1, RIG-I, and CXCL10 detected proteomic signatures of interferon-mediated antiviral signaling that differentiated COVID-19-positive from COVID-19-negative cases. Phosphoproteomic analysis revealed increased phosphorylation of several proteins with known antiviral properties as well as several proteins involved in ciliary function (CEP131 and CFAP57) that have not previously been implicated in the context of coronavirus infections. In addition, decreased phosphorylation levels of AKT and PKC, which have been shown to play varying roles in different viral infections, were observed in infected individuals relative to controls. These data provide novel insights that add depth to our understanding of SARS-CoV-2 infection in the upper airway and establish a proteomic signature for this viral infection.

Proteasome subunit beta type-8 from sevenband grouper negatively regulates cytokine responses by interfering NF-κB signaling upon nervous necrosis viral infection

During viral infection, proper regulation of immune signaling is essential to ensure successful clearance of virus. Immunoproteasome is constitutively expressed and gets induced during viral infection by interferon signaling and contributes to regulate proinflammatory cytokine production and activation of the NF-κB pathway. In this study, we identified Hs-PSMB8, a member of the proteasome β-subunits (PSMB) family, as a negative regulator of NF-κB responses during NNV infection. The transient expression of Hs-PSMB8 delayed the appearance of cytopathic effect (CPE) and showed a higher viral load. The Hs-PSMB8 interacted with NNV which was confirmed using immunocolocalization and co-IP. Overexpression of Hs-PSMB8 diminished virus induced activation of the NF-κB promoters and downregulated the activation of IL-1β, TNFα, IL6, IL8, IFNγ expression upon NNV infection. Collectively, our results demonstrate that PSMB8 is an important regulator of NF-κB signaling during NNV infection in sevenband grouper.

A Set of Markers Related to Viral Infection Has a Sex-sensitive Prognostic Value in Papillary Thyroid Carcinoma

CONTEXT

Although the incidence of papillary thyroid carcinoma (PTC) is significantly higher in females than in males, the prognosis of male PTC is more unfavorable. However, the cause of higher malignancy of PTC in male patients remains unclear.

OBJECTIVE

We conducted our analysis on microarrays datasets, tissue samples from PTC patients and the RNAseq datasets from TCGA with survival data.

METHODS

We searched all publicly available microarray datasets and performed a genome-wide meta-analysis comparing PTC and normal samples. Gene Ontology analysis was then conducted. The candidate genes were tested by quantitative real-time polymerase chain reaction. The analysis of prognostic value of genes was performed with datasets from The Cancer Genome Atlas.

RESULTS

After meta-analyses, 150 significantly differentially expressed genes (DEGs) were specifically found in male subjects. Gene Ontology analysis of these 150 genes revealed that the viral process was activated. Seven genes involved in the viral process in male patients showed a significantly differential expression between PTC and normal tissue. Survival analysis exhibited that the 7 genes, used in combination, were prognostically valuable and, of them, PSMB1 possessed a conspicuous prognostic value, especially in males.

CONCLUSION

In this study, we searched all publicly available microarray datasets and conducted a comprehensive analysis to understand the male propensity for higher malignancy. We found that markers of viral infection showed significantly differential expression only in male patients compared with their female counterparts and had a sex-sensitive prognostic value in PTC.

Host-Viral Interactions Revealed among Shared Transcriptomics Signatures of ARDS and Thrombosis: A Clue into COVID-19 Pathogenesis

Severe novel corona virus disease 2019 (COVID-19) infection is associated with a considerable activation of coagulation pathways, endothelial damage, and subsequent thrombotic microvascular injuries. These consistent observations may have serious implications for the treatment and management of this highly pathogenic disease. As a consequence, the anticoagulant therapeutic strategies, such as low molecular weight heparin, have shown some encouraging results. Cytokine burst leading to sepsis which is one of the primary reasons for acute respiratory distress syndrome (ARDS) drive that could be worsened with the accumulation of coagulation factors in the lungs of COVID-19 patients. However, the obscurity of this syndrome remains a hurdle in making decisive treatment choices. Therefore, an attempt to characterize shared biological mechanisms between ARDS and thrombosis using comprehensive transcriptomics meta-analysis is made. We conducted an integrated gene expression meta-analysis of two independently publicly available datasets of ARDS and venous thromboembolism (VTE). Datasets GSE76293 and GSE19151 derived from National Centre for Biotechnology Information–Gene Expression Omnibus (NCBI-GEO) database were used for ARDS and VTE, respectively. Integrative meta-analysis of expression data (INMEX) tool preprocessed the datasets and effect size combination with random effect modeling was used for obtaining differentially expressed genes (DEGs). Network construction was done for hub genes and pathway enrichment analysis. Our meta-analysis identified a total of 1,878 significant DEGs among the datasets, which when subjected to enrichment analysis suggested inflammation–coagulation–hypoxemia convolutions in COVID-19 pathogenesis. The top hub genes of our study such as tumor protein 53 (TP53), lysine acetyltransferase 2B (KAT2B), DExH-box helicase 9 (DHX9), REL-associated protein (RELA), RING-box protein 1 (RBX1), and proteasome 20S subunit beta 2 (PSMB2) gave insights into the genes known to be participating in the host–virus interactions that could pave the way to understand the various strategies deployed by the virus to improve its replication and spreading.

Saliva proteomic patterns in patients with molar incisor hypomineralization

Molar incisor hypomineralization (MIH) is an endemic pediatric disease with an unclear pathogenesis. Considering that saliva controls enamel remineralization and that MIH is associated with higher saliva flow rate, we hypothesized that the protein composition of saliva is linked to disease. To test this, we enrolled 5 children aged 6-14 years with MIH showing at least one hypersensitive molar and 5 caries-free children without hypomineralization. Saliva samples were subjected to proteomic analysis followed by protein classification in to biological pathways. Among 618 salivary proteins identified with high confidence, 88 proteins were identified exclusively in MIH patients and 16 proteins in healthy controls only. Biological pathway analysis classified these 88 patient-only proteins to neutrophil-mediated adaptive immunity, the activation of the classical pathway of complement activation, extracellular matrix degradation, heme scavenging as well as glutathione -and drug metabolism. The 16 controls-only proteins were associated with adaptive immunity related to platelet degranulation and the lysosome. This report suggests that the proteaneous composition of saliva is affected in MIH patients, reflecting a catabolic environment which is linked to inflammation.