Ceftazidime is a potential drug to inhibit cell proliferation by increasing cellular p27.

The development of new therapeutic uses for existing drugs is important for the treatment of some diseases. Cephalosporin antibiotics stand as the most extensively utilized antibiotics in clinical practice, effectively combating bacterial infections. Here, we found that the antimicrobial drug ceftazidime strongly upregulates p27 protein levels by inhibiting p27 ubiquitination. The p27 protein is a classic negative regulator of the cell cycle. Next, we demonstrated that ceftazidime can impede the cell cycle from G1 to S phase, thus inhibiting cell proliferation. Furthermore, we found that ceftazidime promotes p27 expression and inhibits cell proliferation by reducing Skp2, which is a substrate recognition component of the Skp2-Cullin-F-box (SCF) ubiquitin ligase. Moreover, ceftazidime downregulates transcriptional expression of Skp2. Importantly, we demonstrated that ceftazidime inhibited the proliferation of tumor cells in vivo. These findings reveal ceftazidime-mediated inhibition of cell proliferation through the Skp2-p27 axis, and could provide a potential strategy for anti-tumor therapy.

Exercise activates interferon response of the liver via Gpld1 to enhance antiviral innate immunity.

Healthy behavioral patterns could modulate organ functions to enhance the body's immunity. However, how exercise regulates antiviral innate immunity remains elusive. Here, we found that exercise promotes type I interferon (IFN-I) production in the liver and enhances IFN-I immune activity of the body. Despite the possibility that many exercise-induced factors could affect IFN-I production, we identified Gpld1 as a crucial molecule, and the liver as the major organ to promote IFN-I production after exercise. Exercise largely loses the efficiency to induce IFN-I in Gpld1-/- mice. Further studies demonstrated that exercise-produced 3-hydroxybutanoic acid (3-HB) critically induces Gpld1 expression in the liver. Gpld1 blocks the PP2A-IRF3 interaction, thus enhancing IRF3 activation and IFN-I production, and eventually improving the body's antiviral ability. This study reveals that exercise improves antiviral innate immunity by linking the liver metabolism to systemic IFN-I activity and uncovers an unknown function of liver cells in innate immunity.

Ceftazidime reduces cellular Skp2 to promote type-I interferon activity.

Skp2 plays multiple roles in malignant tumours. Here, we revealed that Skp2 negatively regulates type-I interferon (IFN-I)-mediated antiviral activity. We first noticed that Skp2 can promote virus infection in cells. Further studies demonstrated that Skp2 interacts with IFN-I receptor 2 (IFNAR2) and promotes K48-linked polyubiquitination of IFNAR2, which accelerates the degradation of IFNAR2 proteins. Skp2-mediated downregulation of IFNAR2 levels inhibits IFN-I signalling and IFN-I-induced antiviral activity. In addition, we uncovered for the first time that the antibiotic ceftazidime can act as a repressor of Skp2. Ceftazidime reduces cellular Skp2 levels, thus enhancing IFNAR2 stability and IFN-I antiviral activity. This study reveals a new role of Skp2 in regulating IFN-I signalling and IFN-I antiviral activity and reports the antibiotic ceftazidime as a potential repressor of Skp2.

Necroptosis-related signatures identify two distinct hepatocellular carcinoma subtypes: Implications for predicting drug sensitivity and prognosis.

Background: Necroptosis is associated with oncogenesis, tumor immunity and progression. This research aims to investigate the association of necroptosis-related genes with drug sensitivity and prognosis in hepatocellular carcinoma (HCC). Methods: Based on necroptosis-related signatures, HCC patients retrieved from the TCGA database were categorized. Survival outcomes, mutation profile, immune microenvironment, and drug sensitivity between HCC subtypes were further compared. Then, LASSO analysis was performed to construct a necroptosis-related prognostic signature, which was further evaluated using another independent cohort. Results: A total of 371 patients with HCC could be categorized into two necroptosis-related subtypes. About 36% of patients were allocated to subtype A, with worse survival, more mutant TP53, and a lower likelihood of immunotherapy response. In contrast, patients in subtype B had a favorable prognosis, with lower expression of immunosuppressive signatures but a lower abundance of B and CD8+ T-cell infiltration. The prognostic risk score calculated using the expression levels of nine genes involved in the necroptosis pathway (MLKL, FADD, XIAP, USP22, UHRF1, CASP8, RIPK3, ZBP1, and FAS) showed a significant association with tumor stage, histologic grade, and Child‒Pugh score. Additionally, the risk score model was proven to be accurate in both the training and independent external validation cohorts and performed better than the TNM staging system and three well-recognized risk score models. Conclusions: Based on necroptosis-related signatures, we identified two HCC subtypes with distinctive immune microenvironments, mutation profiles, drug sensitivities, and survival outcomes. A novel well-performing prognostic model was further constructed.

Ubiquitination network in the type I IFN-induced antiviral signaling pathway.

Type I IFN (IFN-I) is the body's first line of defense against pathogen infection. IFN-I can induce cellular antiviral responses and therefore plays a key role in driving antiviral innate and adaptive immunity. Canonical IFN-I signaling activates the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, which induces the expression of IFN-stimulated genes and eventually establishes a complex antiviral state in the cells. Ubiquitin is a ubiquitous cellular molecule for protein modifications, and the ubiquitination modifications of protein have been recognized as one of the key modifications that regulate protein levels and/or signaling activation. Despite great advances in understanding the ubiquitination regulation of many signaling pathways, the mechanisms by which protein ubiquitination regulates IFN-I-induced antiviral signaling have not been explored until very recently. This review details the current understanding of the regulatory network of ubiquitination that critically controls the IFN-I-induced antiviral signaling pathway from three main levels, including IFN-I receptors, IFN-I-induced cascade signals, and effector IFN-stimulated genes.

Methotrexate and Triptolide regulate Notch signaling pathway by targeting the Nedd4-Numb axis.

Methotrexate (MTX) is used to treat rheumatoid arthritis, acute leukemia, and psoriasis. MTX can cause certain side effects, such as myelosuppression, while the exact mechanism of myelosuppression caused by MTX is unknown. Notch signaling pathway has been considered to be essential to regulate hematopoietic stem cell (HSC) regeneration and homeostasis, thus contributing to bone marrow hematopoiesis. However, whether MTX affects Notch signaling remains unexplored. Here, our study provides evidence that MTX strongly suppresses the Notch signaling pathway. We found that MTX inhibited the interaction between Nedd4 with Numb, thus restricting K48-linked polyubiquitination of Numb and stabilizing Numb proteins. This in turn inhibited the Notch signaling pathway by reducing Notch1 protein levels. Interestingly, we found that a monomeric drug, Triptolide, is capable of alleviating the inhibitory effect of MTX on Notch signaling pathway. This study promotes our understanding of MTX-mediated regulation of Notch signaling and could provide ideas to alleviate MTX-induced myelosuppression.

Comparison of adjuvant gemcitabine plus S-1 with S-1 monotherapy for pancreatic ductal adenocarcinoma: Retrospective real-world data.

BACKGROUND: S-1 has been recognized as one of the standard adjuvant chemotherapies for pancreatic ductal adenocarcinoma (PDAC) in East Asia, but the optimal adjuvant chemotherapy regimen has not been determined. We aimed to compare the efficacy and safety of adjuvant gemcitabine plus S-1 (GS) with S-1 monotherapy for PDAC. METHODS: Patients with resected PDAC who received adjuvant GS or S-1 chemotherapy in Peking Union Medical College Hospital between May 2014 and May 2022 were reviewed. Data retrieved from medical records were used to evaluate efficacy and toxicity. RESULTS: A total of 241 patients were included, with 167 receiving GS and 74 receiving S-1. The patients who received GS were generally younger (median [range] age: 62 [36-78] versus 64 [44-87] years, p = 0.004), but chemotherapy began later (median [range] interval between chemotherapy and surgery: 49 [17-125] versus 40 [16-100] days, p < 0.001). The median disease-free survival (DFS, 15.1 versus 15.9 months, p = 0.52) and overall survival (OS, 34.8 versus 27.1 months, p = 0.34) did not differ significantly between the GS and S-1 groups, even after adjustment for the biases. However, the chemotherapy completion rate was higher in the patients treated with S-1 (52.4% versus 75.7%, p = 0.006), while grade 3-4 neutropenia occurred more frequently in the GS group (49.5% versus 18.2%, p = 0.015). CONCLUSIONS: Adjuvant S-1 monotherapy demonstrated noninferiority to the GS regimen in DFS and OS with better tolerability for PDAC following surgery.

Menthone inhibits type-I interferon signaling by promoting Tyk2 ubiquitination to relieve local inflammation of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease. RA development is mediated by the abnormal activation of multiple signaling pathways. Recent studies have revealed that type-I interferon (IFN-I) signaling plays an essential role in the occurrence and development of RA. However, how to target IFN-I signaling to develop anti-rheumatoid arthritis drugs remains largely unexplored. Here, our study showed that IFN-I signaling was over-activated in articular synovial cells from collagen II-induced arthritis (CIA) mice. Interestingly, we found that a small molecule compound, menthone, strongly inhibited the activation of the IFN-I signaling pathway. Further studies revealed that menthone promoted K48-linked polyubiquitination of Tyk2, thus lowering the protein level and stability of Tyk2. Importantly, menthone administration in the local articulus of CIA mice significantly attenuated the local inflammation in CIA mice. This study could promote our understanding of rheumatoid arthritis, and also suggests a potential strategy to develop anti-RA drugs.

Characteristics and Prognostic Nomogram for Primary Lung Lepidic Adenocarcinoma.

Background: Lepidic adenocarcinoma (LPA) is an infrequent subtype of invasive pulmonary adenocarcinoma (ADC). However, the clinicopathological features and prognostic factors of LPA have not been elucidated. Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) database of 4191 LPA patients were retrospectively analyzed and compared with non-LPA pulmonary ADC to explore the clinicopathological and prognosis features of LPA. Univariate and multivariate Cox proportional hazard models were performed to identify independent survival predictors for further nomogram development. The nomograms were validated using the concordance index, receiver operating characteristic curves, and calibration plots, as well as decision curve analysis, in both the training and validation cohorts. Results: Compared with non-LPA pulmonary ADC patients, those with LPA exhibited unique clinicopathological features, including more elderly and female patients, smaller tumor size, less pleural invasion, and lower histological grade and stage. Multivariate analyses showed that age, sex, race, tumor location, primary tumor size, pleural invasion, histological grade, stage, primary tumor surgery, and chemotherapy were independently associated with overall survival (OS) and cancer-specific survival (CSS) in patients with LPA. The nomograms showed good accuracy compared with the actual observed results and demonstrated improved prognostic capacity compared with the TNM stage. Conclusions: LPA is more frequently diagnosed in older people and women. LPA was inclined to be smaller in tumor size and lower in tumor grade and staging, which may indicate a favorable prognosis. The constructed nomograms accurately predict the long-term survival of LPA patients.

E3 ubiquitin ligase MID1 ubiquitinates and degrades type-I interferon receptor 2.

Type I interferon (IFN-I) is a common biological molecule used for the treatment of viral diseases. However, the clinical antiviral efficacy of IFN-I needs to be greatly improved. In this study, IFN-I receptor 2 (IFNAR2) was revealed to undergo degradation at the protein level in cells treated with IFN-I for long periods of time. Further studies found a physical interaction between the E3 ubiquitin ligase midline-1 (MID1) and IFNAR2. As a consequence, MID1 induced both K48- and K63-linked polyubiquitination of IFNAR2, which promoted IFNAR2 protein degradation in a lysosome-dependent manner. Conversely, knockdown of MID1 largely restricted IFN-I-induced degradation of IFNAR2. Importantly, MID1 regulated the strength of IFN-I signalling and IFN-I-induced antiviral activity. These findings reveal a regulatory mechanism of IFNAR2 ubiquitination and protein stability in IFN-I signalling, which could provide a potential target for improving the antiviral efficacy of IFN-I.

LATS1 is a central signal transmitter for achieving full type-I interferon activity.

Interferons (IFNs) have broad-spectrum antiviral activity to resist virus epidemic. However, IFN antiviral efficacy needs to be greatly improved. Here, we reveal that LATS1 is a vital signal transmitter governing full type-I IFN (IFN-I) signaling activity. LATS1 constitutively binds with the IFN-I receptor IFNAR2 and is rapidly tyro-phosphorylated by Tyk2 upon IFN-I engagement. Tyro-phosphorylation of LATS1 promotes LATS1 activation and YAP degradation, thereby promoting IFN-mediated antiproliferation activity. Moreover, activated LATS1 translocates into the nucleus and induces CDK8-Ser62 phosphorylation, which in turn phosphorylates STAT1 at Ser727 and induces full IFN-I antiviral activity. LATS1 deficiency restricts in vivo IFN-I signaling and attenuates host antiviral immune response. Our study identifies IFN-I as a previously unidentified extracellular diffusible ligand signal for activation of the Hippo core LATS1 pathway and reveals Tyk2-LATS1-CDK8 as a complete signaling cascade controlling full IFN-I activity.

A Natural Plant Ingredient, Menthone, Regulates T Cell Subtypes and Lowers Pro-inflammatory Cytokines of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease with nearly 1.6 billion patients worldwide and an incidence of 0.5-1%. In recent years, basic and clinical studies have revealed that immune cell responses and corresponding secretion of inflammatory factors are important in the control of RA development. Our study found that a natural plant ingredient, menthone, could be used as a potential antirheumatism compound. In vivo observations demonstrated that menthone alleviates collagen II-induced arthritis (CIA) in mice. Furthermore, we found that menthone regulates the number of Th1 and Th17 cells in CIA mice. Importantly, menthone significantly inhibits the release of pro-inflammatory cytokines, including TNF-α, IL-1ß, and IL-6, in CIA mice. Our study suggests a potential component for the development of drugs to treat rheumatoid arthritis.

High salt activates p97 to reduce host antiviral immunity by restricting Viperin induction.

High-salt diets have recently been implicated in hypertension, cardiovascular disease, and autoimmune disease. However, whether and how dietary salt affects host antiviral response remain elusive. Here, we report that high salt induces an instant reduction in host antiviral immunity, although this effect is compromised during a long-term high-salt diet. Further studies reveal that high salt stimulates the acetylation at Lys663 of p97, which promotes the recruitment of ubiquitinated proteins for proteasome-dependent degradation. p97-mediated degradation of the deubiquitinase USP33 results in a deficiency of Viperin protein expression during viral infection, which substantially attenuates host antiviral ability. Importantly, switching to a low-salt diet during viral infection significantly enhances Viperin expression and improves host antiviral ability. These findings uncover dietary salt-induced regulation of ubiquitinated cellular proteins and host antiviral immunity, and could offer insight into the daily consumption of salt-containing diets during virus epidemics.

Identification and genomic characterization of a novel porcine parvovirus (PPV6) in China.

BACKGROUND: Parvoviruses are classified into two subfamilies based on their host range: the Parvovirinae, which infect vertebrates, and the Densovirinae, which mainly infect insects and other arthropods. In recent years, a number of novel parvoviruses belonging to the subfamily Parvovirinae have been identified from various animal species and humans, including human parvovirus 4 (PARV4), porcine hokovirus, ovine partetravirus, porcine parvovirus 4 (PPV4), and porcine parvovirus 5 (PPV5). METHODS: Using sequence-independent single primer amplification (SISPA), a novel parvovirus within the subfamily Parvovirinae that was distinct from any known parvoviruses was identified and five full-length genome sequences were determined and analyzed. RESULTS: A novel porcine parvovirus, provisionally named PPV6, was initially identified from aborted pig fetuses in China. Retrospective studies revealed the prevalence of PPV6 in aborted pig fetuses and piglets(50% and 75%, respectively) was apparently higher than that in finishing pigs and sows (15.6% and 3.8% respectively). Furthermore, the prevalence of PPV6 in finishing pig was similar in affected and unaffected farms (i.e. 16.7% vs. 13.6%-21.7%). This finding indicates that animal age, perhaps due to increased innate immune resistance, strongly influences the level of PPV6 viremia. Complete genome sequencing and multiple alignments have shown that the nearly full-length genome sequences were approximately 6,100 nucleotides in length and shared 20.5%-42.6% DNA sequence identity with other members of the Parvovirinae subfamily. Phylogenetic analysis showed that PPV6 was significantly distinct from other known parvoviruses and was most closely related to PPV4. CONCLUSION: Our findings and review of published parvovirus sequences suggested that a novel porcine parvovirus is currently circulating in China and might be classified into the novel genus Copiparvovirus within the subfamily Parvovirinae. However, the clinical manifestations of PPV6 are still unknown in that the prevalence of PPV6 was similar between healthy pigs and sick pigs in a retrospective epidemiological study. The identification of PPV6 within the subfamily Parvovirinae provides further insight into the viral and genetic diversity of parvoviruses.

Autoregulation of lantibiotic bovicin HJ50 biosynthesis by the BovK-BovR two-component signal transduction system in Streptococcus bovis HJ50.

Streptococcus bovis HJ50 produces a lacticin 481-like 33-amino-acid-residue lantibiotic, designated bovicin HJ50. bovK-bovR in the bovicin HJ50 biosynthetic gene cluster is predicted to be a two-component signal transduction system involved in sensing signals and regulating gene expression. Disruption of bovK or bovR resulted in the abrogation of bovicin HJ50 production, suggesting both genes play important roles in bovicin HJ50 biosynthesis. Addition of exogenous bovicin HJ50 peptide to cultures of a bovM mutant that lost the capability for bovicin HJ50 production and structural gene bovA transcription in S. bovis HJ50 induced dose-dependent transcription of the bovA gene, demonstrating that bovicin HJ50 production was normally autoregulated. The transcription of bovA was no longer induced by bovicin HJ50 in bovK and bovR disruption mutants, suggesting that BovK-BovR plays an essential role in the signal transduction regulating bovicin HJ50 biosynthesis. A phosphorylation assay indicated that BovK has the ability to autophosphorylate and subsequently transfer the phosphoryl group to the downstream BovR protein to carry on signal transduction. Electromobility shift assays (EMSA) and green fluorescent protein (GFP) reporter gene expression assays showed the specific binding of BovR to the bovA promoter, indicating that BovR regulates bovA expression by direct binding between them. Taken together, bovicin HJ50 biosynthesis is induced by bovicin HJ50 itself and regulated via the two-component signal transduction system BovK-BovR.

[Development and application of real-time quantitative RT- PCR assay for the detection of hepatitis E virus].

Hepatitis E virus (HEV) sequences including four major genotypes representative strains available in GenBank were aligned with the DNAMAN software. The highly conserved internal region of ORF2 was then subjected to design primers and a probe. Furthermore, a 0.3 kb fragment of HEV ORF2 containing the amplification region was transcribed in vitro to synthese cRNA standard and a universal real-time TaqMan PCR assay was optimized and developed to detect and quantify main genotypes RNA of HEV. The specificity and reliability of the real-time RT-PCR was confirmed by testing genotype I HEV, genotype IV HEV and clinical samples. The detection limit of real-time RT-PCR was found 2.0 x 10(1) copies per reaction using in vitro transcribed cRNA. Compared with nested RT-PCR in diagnosis of HEV, the real-time RT-PCR developed was 10 to 100-fold more sensitive than the nested RT-PCR. The detection results from 54 clinical specimens indicated real-time RT-PCR was a rapid, sensitive and reproducible diagnostic method for HEV. This assay will be useful as an early and rapid diagnostic assay for HEV.