Cellular senescence, DNA damage, and neuroinflammation in the aging brain.

Aging may lead to low-level chronic inflammation that increases the susceptibility to age-related conditions, including memory impairment and progressive loss of brain volume. As brain health is essential to promoting healthspan and lifespan, it is vital to understand age-related changes in the immune system and central nervous system (CNS) that drive normal brain aging. However, the relative importance, mechanistic interrelationships, and hierarchical order of such changes and their impact on normal brain aging remain to be clarified. Here, we synthesize accumulating evidence that age-related DNA damage and cellular senescence in the immune system and CNS contribute to the escalation of neuroinflammation and cognitive decline during normal brain aging. Targeting cellular senescence and immune modulation may provide a logical rationale for developing new treatment options to restore immune homeostasis and counteract age-related brain dysfunction and diseases.

Multiple E3 ligases act as antiviral factors against SARS-CoV-2 via inducing the ubiquitination and degradation of ORF9b.

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) open reading frame 9b (ORF9b) antagonizes the antiviral type I and III interferon (IFN) responses and is ubiquitinated and degraded via the ubiquitin-proteasome pathway. However, E3 ubiquitin ligases that mediate the polyubiquitination and degradation of ORF9b remain unknown. In this study, we identified 14 E3 ligases that specifically bind to SARS-CoV-2 ORF9b. Specifically, three E3 ligases, HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 (HUWE1), ubiquitin protein ligase E3 component n-recognin 4 (UBR4), and UBR5, induced K48-linked polyubiquitination and degradation of ORF9b, thereby attenuating ORF9b-mediated inhibition of the IFN response and SARS-CoV-2 replication. Moreover, each E3 ligase performed this function independent of the other two E3 ligases. Therefore, the three E3 ligases identified in this study as anti-SARS-CoV-2 host factors provide novel molecular insight into the virus-host interaction.IMPORTANCEUbiquitination is an important post-translational modification that regulates multiple biological processes, including viral replication. Identification of E3 ubiquitin ligases that target viral proteins for degradation can provide novel targets for antagonizing viral infections. Here, we identified multiple E3 ligases, including HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 (HUWE1), ubiquitin protein ligase E3 component n-recognin 4 (UBR4), and UBR5, that ubiquitinated and induced the degradation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) open reading frame 9b (ORF9b), an interferon (IFN) antagonist, thereby enhancing IFN production and attenuating SARS-CoV-2 replication. Our study provides new possibilities for drug development targeting the interaction between E3 ligases and ORF9b.

Pathways for macrophage uptake of cell-free circular RNAs.

Circular RNAs (circRNAs) are stable RNAs present in cell-free RNA, which may comprise cellular debris and pathogen genomes. Here, we investigate the phenomenon and mechanism of cellular uptake and intracellular fate of exogenous circRNAs. Human myeloid cells and B cells selectively internalize extracellular circRNAs. Macrophage uptake of circRNA is rapid, energy dependent, and saturable. CircRNA uptake can lead to translation of encoded sequences and antigen presentation. The route of internalization influences immune activation after circRNA uptake, with distinct gene expression programs depending on the route of RNA delivery. Genome-scale CRISPR screens and chemical inhibitor studies nominate macrophage scavenger receptor MSR1, Toll-like receptors, and mTOR signaling as key regulators of receptor-mediated phagocytosis of circRNAs, a dominant pathway to internalize circRNAs in parallel to macropinocytosis. These results suggest that cell-free circRNA serves as an "eat me" signal and danger-associated molecular pattern, indicating orderly pathways of recognition and disposal.

Helicobacter pylori causes gastric dysbacteriosis in chronic gastritis patients.

Gastric mucosal samples were procured and underwent the sequencing of 16S ribosomal RNA (16S rRNA) via Illumina high-throughput sequencing technology to explore the impact of Helicobacter pylori (H. pylori) infection on the composition of gastric flora in chronic gastritis (CG) patients. In the results, the operational taxonomic unit (OTU) analysis revealed an overlap of 5706 OTUs shared between the two groups. The top 5 abundance ranking (TOP5) phyla comprised Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria, and Epsilonbacteraeota, while the TOP5 genus was Lachnospiraceae_NK4A136_group, Helicobacter, Bacteroides, Klebsiella, and Pseudomonas. In the metabolic pathways at the Kyoto Encyclopedia of Genes and Genomes (KEGG)_L3 level, conspicuous variations across seven functions were observed between the H. pylori-positive (HP_Pos) and H. pylori-negative (HP_Neg) groups. Subsequently, functional gene enrichment in KEGG pathways was further validated through animal experimentation. In contrast to the mice in the HP_Neg group, those infected with H. pylori manifested an infiltration of inflammatory cells, an augmentation in gastric acid secretion, and conspicuously elevated scores regarding gastric activity, along with heightened levels of malondialdehyde. In conclusion, CG patients infected with H. pylori displayed a disorder in gastric flora, furnishing a theoretical basis for the prophylaxis of H. pylori infection and its associated pathogenic ramifications.

ODF3B affects the proliferation and apoptosis of glioma via the JAK/STAT pathway.

The pathogenesis of glioma has remained unclear. In this study, it was found that high expression of the outer dense fibers of sperm tail 3B (ODF3B) in gliomas was positively correlated with the grade of glioma. The higher the grade, the worse the prognosis. ODF3B is closely related to the growth and apoptosis of glioma. In terms of mechanism, ODF3B was found to affect the proliferation and apoptosis of glioma through the JAK1 and JAK2/STAT3 pathways. ODF3B was also found to affect the growth and apoptosis of glioma in vivo. We conclude that ODF3B affects glioma proliferation and apoptosis via the JAK/STAT pathway and is a potential therapeutic target.

Polyunsaturated fatty acid-derived lipid mediator Resolvin D1 alleviates sepsis-induced disseminated intravascular coagulation via Caspase-1/Gasdermin D pyroptotic pathway.

BACKGROUND & AIMS: Sepsis-induced disseminated intravascular coagulation (DIC) is characterised by abnormal blood clotting resulting from severe infection, contributing to organ dysfunction in sepsis. Resolvin D1 (RvD1) is an endogenous lipid mediator, synthesised from the omega-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) through enzymatic processes involving 15-LOX and 5-LOX. RvD1 is recognised for its protective properties against various inflammatory conditions. This study aims to investigate its potential to modulate coagulation dysfunction in sepsis and to evaluate coagulation disorders in septic patients. METHODS: Sepsis models were established by intraperitoneal injection LPS (20 mg/kg) or cecal ligation and puncture (CLP) followed by injection of RvD1 (10 µg/kg) or saline. The impact of RvD1 on coagulation dysfunction was assessed by clotting time and coagulation indicators such as TAT, D-dimer, PAI-1, and fibrinogen. The activity of the coagulation system in vivo was observed by evaluating dynamic microcirculation, platelets and thrombin in mice using intravital microscopy. The effect of RvD1 on pyroptosis was investigated by measuring NOD-like receptor protein 3 (NLRP3), Caspase-1, Caspase-11, and Gasdermin D (GSDMD) levels via western blot. Caspase-1 knockout mice, GSDMD knockout mice and bone marrow-derived macrophages (BMDMs) were used to elucidate the underlying mechanisms. Lastly, the concentration of RvD1 in plasma from septic patients was quantified to explore its relationship with coagulation and pyroptosis. RESULTS: RvD1 significantly attenuated coagulation dysfunction in septic mice induced by LPS and CLP, and inhibited Caspase-1/GSDMD-dependent pyroptosis in septic mice and bone marrow-derived macrophages. In septic patients, the plasma concentrations of RvD1 was negatively correlated with both coagulation-related indicators and markers of GSDMD activation. CONCLUSION: The results suggest that RvD1 can improve coagulation dysfunction in sepsis by regulating the Caspase-1/GSDMD pyroptotic pathway. Additionally, the concentration of RvD1 in septic patient plasma is related to prognosis and DIC development. RvD1 could be a potential biomarker and a promising therapeutic alternative in sepsis-induced DIC.

Physician Versus Large Language Model Chatbot Responses to Web-Based Questions From Autistic Patients in Chinese: Cross-Sectional Comparative Analysis.

BACKGROUND: There is a dearth of feasibility assessments regarding using large language models (LLMs) for responding to inquiries from autistic patients within a Chinese-language context. Despite Chinese being one of the most widely spoken languages globally, the predominant research focus on applying these models in the medical field has been on English-speaking populations. OBJECTIVE: This study aims to assess the effectiveness of LLM chatbots, specifically ChatGPT-4 (OpenAI) and ERNIE Bot (version 2.2.3; Baidu, Inc), one of the most advanced LLMs in China, in addressing inquiries from autistic individuals in a Chinese setting. METHODS: For this study, we gathered data from DXY-a widely acknowledged, web-based, medical consultation platform in China with a user base of over 100 million individuals. A total of 100 patient consultation samples were rigorously selected from January 2018 to August 2023, amounting to 239 questions extracted from publicly available autism-related documents on the platform. To maintain objectivity, both the original questions and responses were anonymized and randomized. An evaluation team of 3 chief physicians assessed the responses across 4 dimensions: relevance, accuracy, usefulness, and empathy. The team completed 717 evaluations. The team initially identified the best response and then used a Likert scale with 5 response categories to gauge the responses, each representing a distinct level of quality. Finally, we compared the responses collected from different sources. RESULTS: Among the 717 evaluations conducted, 46.86% (95% CI 43.21%-50.51%) of assessors displayed varying preferences for responses from physicians, with 34.87% (95% CI 31.38%-38.36%) of assessors favoring ChatGPT and 18.27% (95% CI 15.44%-21.10%) of assessors favoring ERNIE Bot. The average relevance scores for physicians, ChatGPT, and ERNIE Bot were 3.75 (95% CI 3.69-3.82), 3.69 (95% CI 3.63-3.74), and 3.41 (95% CI 3.35-3.46), respectively. Physicians (3.66, 95% CI 3.60-3.73) and ChatGPT (3.73, 95% CI 3.69-3.77) demonstrated higher accuracy ratings compared to ERNIE Bot (3.52, 95% CI 3.47-3.57). In terms of usefulness scores, physicians (3.54, 95% CI 3.47-3.62) received higher ratings than ChatGPT (3.40, 95% CI 3.34-3.47) and ERNIE Bot (3.05, 95% CI 2.99-3.12). Finally, concerning the empathy dimension, ChatGPT (3.64, 95% CI 3.57-3.71) outperformed physicians (3.13, 95% CI 3.04-3.21) and ERNIE Bot (3.11, 95% CI 3.04-3.18). CONCLUSIONS: In this cross-sectional study, physicians' responses exhibited superiority in the present Chinese-language context. Nonetheless, LLMs can provide valuable medical guidance to autistic patients and may even surpass physicians in demonstrating empathy. However, it is crucial to acknowledge that further optimization and research are imperative prerequisites before the effective integration of LLMs in clinical settings across diverse linguistic environments can be realized. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300074655; https://www.chictr.org.cn/bin/project/edit?pid=199432.

Study on activation of fluorogypsum by sodium sulfate and sodium nitrite.

Given the issues related to poor hydration activity, long setting time and low early strength of industrial by-product fluorogypsum (FG), the composite modifiers (Na2SO4 and NaNO2) were utilized to enhance its reactivity. The investigation of the mechanism involved the utilization of contemporary analytical methods, including X-ray diffraction (XRD), 1H low-field nuclear magnetic resonance (NMR), and Scanning electron microscope and Energy Dispersive Spectrometer (SEM-EDS). The results demonstrated that the incorporation of modifiers significantly enhanced both the hydration rate and activity of fluorogypsum. The optimum concentration of the composite modifier was found to be 1.5 wt% Na2SO4 and 0.5 wt% NaNO2. The addition of modifiers (1.5 wt% Na2SO4 and 0.5 wt% NaNO2) significantly shortens the setting time of FG paste, reducing it by approximately 500 min compared to the control sample. After 28 days of curing, the flexural strength and compressive strength of the fluorogypsum sample containing modifiers (1.5 wt% Na2SO4 and 0.5 wt% NaNO2) increased by 55.5 % (reaching 4.2 MPa) and 31.5 % (reaching 37.6 MPa), respectively. The modifiers facilitate the transformation from anhydrite (CaSO4, AH) to dihydrate gypsum (CaSO4·2H2O, DH). Both NaNO2 and Na2SO4 alter the growth rates of different crystal axes during DH crystal growth, transforming them into prismatic and needle-shaped DH. The prismatic and needle-shaped DH crystals were arranged in layers, resulting in a compact structure with low hole content and few pores, which led to increased density of the hardened paste and higher strength. The current study provides evidence that the inclusion of composite modifiers greatly improves the activity of FG, making it more efficient in the field of building materials.

Effects of sustained viral response on lipid in Hepatitis C: a systematic review and meta-analysis.

BACKGROUND: Direct-acting Antiviral Agents (DAAs) influence serum lipids of patients with Hepatitis C virus (HCV). This paper presents an analysis of the relevant literature to investigate the effects of DAAs in treating hepatitis C to achieve a sustained viral response (SVR) on lipid parameters. METHODS: PubMed,Web of science, Embase and Central databases were searched, with a deadline of September 2023. Studies on the effects of sustained viral response on lipid parameters after DAAs treatment for hepatitis C were selected. The required information was extracted from the included studies, and then the Stata 12.0 was used to analyze the data quantitatively. RESULTS: Of 32 studies, the results showed that total cholesterol (TC) levels increased from the end of treatment (WMD = 20.144, 95%CI = 3.404, 36.884,P = 0.018) to one year after treatment (WMD = 24.900, 95%CI = 13.669, 36.131, P < 0.001). From the end of treatment (WMD = 17.728, 95%CI = 4.375, 31.082, P = 0.009) to one year after treatment (WMD = 18.528, 95%CI = 7.622, 29.433, P < 0.001), the levels of low-density lipoprotein (LDL) were also increased. High-density lipoprotein (HDL) levels were elevated from 4 weeks after treatment (WMD = 6.665, 95%CI = 3.906, 9.424, P < 0.001) to 24 weeks after treatment (WMD = 3.159,95% CI = 0.176, 6.142, P = 0.038). Triglyceride (TG) levels showed no significant change after the treatment. CONCLUSIONS: Hepatitis C patients who achieved SVR on DAAs showed the increase of lipid levels and the improvement of hepatic inflammation indicators AST and ALT. This may provide evidence-based medical evidence for the follow-up and monitoring of blood lipids and hyperlipidemia treatment. REGISTRATION: PROSPERO CRD42020180793.

Lactating nurses' experiences of return to work after lifting COVID-19 lockdown: A qualitative study.

Aim: To explore the lactating nurses' experiences of return to work after lifting COVID-19 lockdown. Background: Return to work is a key reason for the low rates of breastfeeding. Especially after lifting COVID-19 lockdown, case counts reached recorded highs. So lactating nurses face more challenges when they return to work. Method: The empirical phenomenology method was used to conduct a qualitative study. Lactating nurses were recruited in a tertiary hospital through purposive and snowball sampling, and participated in semi-structured video interviews. Colaizzi's method was used to analyze the data. Results: Three themes and 10 sub-themes emerged from the interview data of 15 participants. The first theme was "preparation for return to work", which helped lactating nurses adapt to return to work quickly. The second was "experiences of return to work". The inconvenience of pumping was mentioned repeatedly. In addition, the flexible work schedule was highlighted. The third was "experiences of infection". The attitudes toward breastfeeding differed due to different perceptions of COVID-19. Conclusions: Lactation nurses easily interrupted or stopped breastfeeding when they returned to work after lifting COVID-19 lockdown. Recommendations include the further provision of longer periods of leave, flexible working arrangements, separate facilities for breast pumping, and breastfeeding strategies for epidemics.

Scalable Synthesis of Robust MOF for Challenging Ethylene Purification and Propylene Recovery with Record Productivity.

Ethylene (C2H4) purification and propylene (C3H6) recovery are highly relevant in polymer synthesis, yet developing physisorbents for these industrial separation faces the challenges of merging easy scalability, economic feasibility, high moisture stability with great separation efficiency. Herein, we reported a robust and scalable MOF (MAC-4) for simultaneous recovery of C3H6 and C2H4. Through creating nonpolar pores decorated by accessible N/O sites, MAC-4 displays top-tier uptakes and selectivities for C2H6 and C3H6 over C2H4 at ambient conditions. Molecular modelling combined with infrared spectroscopy revealed that C2H6 and C3H6 molecules were trapped in the framework with stronger contacts relative to C2H4. Breakthrough experiments demonstrated exceptional separation performance for binary C2H6/C2H4 and C3H6/C2H4 as well as ternary C3H6/C2H6/C2H4 mixtures, simultaneously affording record productivities of 27.4 and 36.2 L kg-1 for high-purity C2H4 (≥99.9 %) and C3H6 (≥99.5 %). MAC-4 was facilely prepared at deckgram-scale under reflux condition within 3 hours, making it as a smart MOF to address challenging gas separations.

Influence of the Injection Bias on the Capacitive Sensing of the Test Mass Motion of Satellite Gravity Gradiometers.

The performance of the capacitive gap-sensing system plays a critical role in a satellite-based gravity gradiometer that is developed using an electrostatic accelerometer. The capacitive sensing gain mainly depends on the stabilized injection bias amplitude, the gain of the transformer bridge, and the trans-impedance amplifier. Previous studies have indicated that amplitude noise is the main factor influencing the noise of capacitive displacement detection. Analyzing the capacitive gap-sensing system indicates that the amplitude, frequency, phase, and broadband noises of the stabilized injection bias have varying levels of influence on the performance of the detection system. This paper establishes a model to clarify the mentioned effects. The validation of the sub-tests demonstrates that the analysis and evaluation results of various noise coefficients are highly consistent with the model's predicted outcomes.

Logic "AND Gate Circuit"-Based Gasdermin Protein Expressing Nanoplatform Induces Tumor-Specific Pyroptosis to Enhance Cancer Immunotherapy.

Pyroptosis mediated by gasdermin protein has shown great potential in cancer immunotherapies. However, the low expression of gasdermin proteins and the systemic toxicity of nonspecific pyroptosis limit its clinical application. Here, we designed a synthetic biology strategy to construct a tumor-specific pyroptosis-inducing nanoplatform M-CNP/Mn@pPHS, in which a pyroptosis-inducing plasmid (pPHS) was loaded onto a manganese (Mn)-doped calcium carbonate nanoparticle and wrapped in a tumor-derived cell membrane. M-CNP/Mn@pPHS showed an efficient tumor targeting ability. After its internalization by tumor cells, the degradation of M-CNP/Mn@pPHS in the acidic endosomal environment allowed the efficient endosomal escape of plasmid pPHS. To trigger tumor-specific pyroptosis, pPHS was designed according to the logic "AND gate circuit" strategy, with Hif-1α and Sox4 as two input signals and gasdermin D induced pyroptosis as output signal. Only in cells with high expression of Hif-1α and Sox4 simultaneously will the output signal gasdermin D be expressed. Since Hif-1α and Sox4 are both specifically expressed in tumor cells, M-CNP/Mn@pPHS induces the tumor-specific expression of gasdermin D and thus pyroptosis, triggering an efficient immune response with little systemic toxicity. The Mn2+ released from the nanoplatform further enhanced the antitumor immune response by stimulating the cGAS-STING pathway. Thus, M-CNP/Mn@pPHS efficiently inhibited tumor growth with 79.8% tumor regression in vivo. We demonstrate that this logic "AND gate circuit"-based gasdermin nanoplatform is a promising strategy for inducing tumor-specific pyroptosis with little systemic toxicity.

Biomimetic-gasdermin-protein-expressing nanoplatform mediates tumor-specific pyroptosis for cancer immunotherapy.

Pyroptosis, mediated by gasdermin proteins, has shown excellent efficacy in facilitating cancer immunotherapy. The strategies commonly used to induce pyroptosis suffer from a lack of tissue specificity, resulting in the nonselective activation of pyroptosis and consequent systemic toxicity. Moreover, pyroptosis activation usually depends on caspase, which can induce inflammation and metabolic disorders. In this study, inspired by the tumor-specific expression of SRY-box transcription factor 4 (Sox4) and matrix metalloproteinase 2 (MMP2), we constructed a doubly regulated plasmid, pGMD, that expresses a biomimetic gasdermin D (GSDMD) protein to induce the caspase-independent pyroptosis of tumor cells. To deliver pGMD to tumor cells, we used a hyaluronic acid (HA)-shelled calcium carbonate nanoplatform, H-CNP@pGMD, which effectively degrades in the acidic endosomal environment, releasing pGMD into the cytoplasm of tumor cells. Upon the initiation of Sox4, biomimetic GSDMD was expressed and cleaved by MMP2 to induce tumor-cell-specific pyroptosis. H-CNP@pGMD effectively inhibited tumor growth and induced strong immune memory effects, preventing tumor recurrence. We demonstrate that H-CNP@pGMD-induced biomimetic GSDMD expression and tumor-specific pyroptosis provide a novel approach to boost cancer immunotherapy.

CRL4B E3 ligase recruited by PRPF19 inhibits SARS-CoV-2 infection by targeting ORF6 for ubiquitin-dependent degradation.

The accessory protein ORF6 of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a key interferon (IFN) antagonist that strongly suppresses the production of primary IFN as well as the expression of IFN-stimulated genes. However, how host cells respond to ORF6 remains largely unknown. Our research of ORF6-binding proteins by pulldown revealed that E3 ligase components such as Cullin 4B (CUL4B), DDB1, and RBX1 are potential ORF6-interacting proteins. Further study found that the substrate recognition receptor PRPF19 interacts with CUL4B, DDB1, and RBX1 to form a CRL4B-based E3 ligase, which catalyzes ORF6 ubiquitination and subsequent degradation. Overexpression of PRPF19 promotes ORF6 degradation, releasing ORF6-mediated IFN inhibition, which inhibits SARS-CoV-2 replication. Moreover, we found that activation of CUL4B by the neddylation inducer etoposide alleviates lung lesions in a SARS-CoV-2 mouse infection model. Therefore, targeting ORF6 for degradation may be an effective therapeutic strategy against SARS-CoV-2 infection.IMPORTANCEThe cellular biological function of the ubiquitin-proteasome pathway as an important modulator for the regulation of many fundamental cellular processes has been greatly appreciated. The critical role of the ubiquitin-proteasome pathway in viral pathogenesis has become increasingly apparent. It is a powerful tool that host cells use to defend against viral infection. Some cellular proteins can function as restriction factors to limit viral infection by ubiquitin-dependent degradation. In this research, we identificated of CUL4B-DDB1-PRPF19 E3 Ubiquitin Ligase Complex can mediate proteasomal degradation of ORF6, leading to inhibition of viral replication. Moreover, the CUL4B activator etoposide alleviates disease development in a mouse infection model, suggesting that this agent or its derivatives may be used to treat infections caused by SARS-CoV-2. We believe that these results will be extremely useful for the scientific and clinic communities in their search for cues and preventive measures to combat the COVID-19 pandemic.

Postoperative mediastinitis and sternal osteitis after cardiac surgery caused by Mycoplasma hominis: A case report.

BACKGROUND: Mediastinitis and sternal osteitis are critical complications in cardiac surgery. Cases of these complications caused by Mycoplasma hominis are extremely rare. CASE PRESENTATION: We present a case of mediastinitis and sternal osteitis caused by M. hominis infection following ascending aortic replacement surgery. Whole gene sequencing analysis suggested the genitourinary tract as the most likely source of this M. hominis infection. Successful infection control was achieved through a regimen of moxifloxacin treatment. Additionally, a notable correlation was observed between serum levels of interleukin-6 and M. hominis infection. CONCLUSIONS: The significance of M. hominis as a potential cause of postoperative infection in cardiac surgery is still not fully recognized. Special attention should be paid to patients with bacteriologically negative infections, as M. hominis should not be disregarded, despite its rarity.

Deubiquitinase USP1 regulates sarbecovirus ORF6 protein function.

SARS-CoV-2 belongs to the subgenus Sarbecovirus, which universally encodes the accessory protein ORF6. SARS-CoV-2 ORF6 is an antagonist of the interferon (IFN)-mediated antiviral response and plays an important role in viral infections. However, the mechanism by which the host counteracts the function of ORF6 to restrict viral replication remains unclear. In this study, we found that most ORF6 proteins encoded by sarbecoviruses could be ubiquitinated and subsequently degraded via the proteasome pathway. Through extensive screening, we identified that the deubiquitinase USP1, which effectively and broadly deubiquitinates sarbecovirus ORF6 proteins, stabilizes ORF6 proteins, resulting in enhanced viral replication. Therefore, ubiquitination and deubiquitination of ORF6 are important for antagonizing IFN-mediated antiviral signaling and influencing the virulence of SARS-CoV-2. These findings highlight an essential molecular mechanism and may provide a novel target for therapeutic interventions against viral infections.IMPORTANCEThe ORF6 proteins encoded by sarbecoviruses are essential for effective viral replication and infection and are important targets for developing effective intervention strategies. In this study, we confirmed that sarbecovirus ORF6 proteins are important antagonists of the host immune response and identified the regulatory mechanisms of ubiquitination and deubiquitination of most sarbecovirus ORF6 proteins. Moreover, we revealed that DUB USP1 prevents the proteasomal degradation of all ORF6 proteins, thereby promoting the virulence of SARS-CoV-2. Thus, impeding ORF6 function is helpful for attenuating the virulence of sarbecoviruses. Therefore, our findings provide a deeper understanding of the molecular mechanisms underlying sarbecovirus infections and offer potential new therapeutic targets for the prevention and treatment of these infections.

Histone methyltransferase KMT2D inhibits ENKTL carcinogenesis by epigenetically activating SGK1 and SOCS1.

BACKGROUND: Epigenetic alteration plays an essential role in the occurrence and development of extranodal natural killer/T cell lymphoma (ENKTL). Histone methyltransferase (HMT) KMT2D is an epigenetic regulator that plays different roles in different tumors, but its role and mechanism in ENKTL are still unclear. METHODS: We performed immunohistochemical staining of 112 ENKTL formalin-fixed paraffin-embedded (FFPE) samples. Then, we constructed KMT2D knockdown cell lines and conducted research on cell biological behavior. Finally, to further investigate KMT2D-mediated downstream genes, ChIP-seq and ChIP -qPCR was performed. RESULTS: The low expression of KMT2D was related to a decreased abundance in histone H3 lysine 4 mono- and trimethylation (H3K4me1/3). In KMT2D knockdown YT and NK-YS cells, cell proliferation was faster (P < 0.05), apoptosis was decreased (P < 0.05), the abundance of S phase cells was increased (P < 0.05), and the level of H3K4me1 was decreased. Notably, ChIP-seq revealed two crucial genes and pathways downregulated by KMT2D. CONCLUSIONS: KMT2D is a tumor suppressor gene that mediates H3K4me1 and influences ENKTL proliferation and apoptosis by regulating the cell cycle. Moreover, in ENKTL, serum- and glucocorticoid-inducible kinase-1 (SGK1) and suppressor of cytokine signaling-1 (SOCS1) are downstream genes of KMT2D.

LncRNA NKILA inhibits HBV replication by repressing NF-κB signalling activation.

Hepatitis B virus (HBV) infection results in liver cirrhosis and hepatocellular carcinoma (HCC). HBx/nuclear factor (NF)-κB pathway plays a role in HBV replication. However, whether NF-κB-interacting long noncoding RNA (NKILA), a suppressor of NF-κB activation, regulates HBV replication remains largely unknown. In this study, gain-and-loss experiments showed that NKILA inhibited HBV replication by inhibiting NF-κB activity. In turn, HBV infection down-regulated NKILA expression. In addition, expression levels of NKILA were lower in the peripheral blood-derived monocytes (PBMCs) of HBV-positive patients than in healthy individuals, which were correlated with HBV viral loads. And a negative correlation between NKILA expression level and HBV viral loads was observed in blood serum from HBV-positive patients. Lower levels of endogenous NKILA were also observed in HepG2 cells expressing a 1.3-fold HBV genome, HBV-infected HepG2-NTCP cells, stable HBV-producing HepG2.2.15 and HepAD38 â€‹cells, compared to those HBV-negative cells. Furthermore, HBx was required for NKILA-mediated inhibition on HBV replication. NKILA decreased HBx-induced NF-κB activation by interrupting the interaction between HBx and p65, whereas NKILA mutants lack of essential domains for NF-ĸB inhibition, lost the ability to inhibit HBV replication. Together, our data demonstrate that NKILA may serve as a suppressor of HBV replication via NF-ĸB signalling.