The HN protein of Newcastle disease virus induces cell apoptosis through the induction of lysosomal membrane permeabilization.

Lysosomes are acidic organelles that mediate the degradation and recycling of cellular waste materials. Damage to lysosomes can cause lysosomal membrane permeabilization (LMP) and trigger different types of cell death, including apoptosis. Newcastle disease virus (NDV) can naturally infect most birds. Additionally, it serves as a promising oncolytic virus known for its effective infection of tumor cells and induction of intensive apoptotic responses. However, the involvement of lysosomes in NDV-induced apoptosis remains poorly understood. Here, we demonstrate that NDV infection profoundly triggers LMP, leading to the translocation of cathepsin B and D and subsequent mitochondria-dependent apoptosis in various tumor and avian cells. Notably, the released cathepsin B and D exacerbate NDV-induced LMP by inducing the generation of reactive oxygen species. Additionally, we uncover that the viral Hemagglutinin neuraminidase (HN) protein induces the deglycosylation and degradation of lysosome-associated membrane protein 1 (LAMP1) and LAMP2 dependent on its sialidase activity, which finally contributes to NDV-induced LMP and cellular apoptosis. Overall, our findings elucidate the role of LMP in NDV-induced cell apoptosis and provide novel insights into the function of HN during NDV-induced LMP, which provide innovative approaches for the development of NDV-based oncolytic agents.

The NP protein of Newcastle disease virus dictates its oncolytic activity by regulating viral mRNA translation efficiency.

Newcastle disease virus (NDV) has been extensively studied as a promising oncolytic virus for killing tumor cells in vitro and in vivo in clinical trials. However, the viral components that regulate the oncolytic activity of NDV remain incompletely understood. In this study, we systematically compared the replication ability of different NDV genotypes in various tumor cells and identified NP protein determines the oncolytic activity of NDV. On the one hand, NDV strains with phenylalanine (F) at the 450th amino acid position of the NP protein (450th-F-NP) exhibit a loss of oncolytic activity. This phenotype is predominantly associated with genotype VII NDVs. In contrast, the NP protein with a leucine amino acid at this site in other genotypes (450th-L-NP) can facilitate the loading of viral mRNA onto ribosomes more effectively than 450th-F-NP. On the other hand, the NP protein from NDV strains that exhibit strong oncogenicity interacts with eIF4A1 within its 366-489 amino acid region, leading to the inhibition of cellular mRNA translation with a complex 5' UTR structure. Our study provide mechanistic insights into how highly oncolytic NDV strains selectively promote the translation of viral mRNA and will also facilitate the screening of oncolytic strains for oncolytic therapy.

The Drosophila NPY-like system protects against chronic stress-induced learning deficit by preventing the disruption of autophagic flux.

Chronic stress may induce learning and memory deficits that are associated with a depression-like state in Drosophila melanogaster. The molecular and neural mechanisms underlying the etiology of chronic stress-induced learning deficit (CSLD) remain elusive. Here, we show that the autophagy-lysosomal pathway, a conserved cellular signaling mechanism, is associated with chronic stress in Drosophila, as indicated by time-series transcriptome profiling. Our findings demonstrate that chronic stress induces the disruption of autophagic flux, and chronic disruption of autophagic flux could lead to a learning deficit. Remarkably, preventing the disruption of autophagic flux by up-regulating the basal autophagy level is sufficient to protect against CSLD. Consistent with the essential role of the dopaminergic system in modulating susceptibility to CSLD, dopamine neuronal activity is also indispensable for chronic stress to induce the disruption of autophagic flux. By screening knockout mutants, we found that neuropeptide F, the Drosophila homolog of neuropeptide Y, is necessary for normal autophagic flux and promotes resilience to CSLD. Moreover, neuropeptide F signaling during chronic stress treatment promotes resilience to CSLD by preventing the disruption of autophagic flux. Importantly, neuropeptide F receptor activity in dopamine neurons also promotes resilience to CSLD. Together, our data elucidate a mechanism by which stress-induced excessive dopaminergic activity precipitates the disruption of autophagic flux, and chronic disruption of autophagic flux leads to CSLD, while inhibitory neuropeptide F signaling to dopamine neurons promotes resilience to CSLD by preventing the disruption of autophagic flux.

Targeting FoxO proteins induces lytic reactivation of KSHV for treating herpesviral primary effusion lymphoma.

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus consisting of both latent and lytic life cycles. Primary effusion lymphoma (PEL) is an aggressive B-cell lineage lymphoma, dominantly latently infected by KSHV. The latent infection of KSHV is persistent and poses an obstacle to killing tumor cells. Like the "shock and kill" strategy designed to eliminate latent HIV reservoir, methods that induce viral lytic reactivation in tumor latently infected by viruses represent a unique antineoplastic strategy, as it could potentially increase the specificity of cytotoxicity in cancer. Inspired by this conception, we proposed that the induction of KSHV lytic reactivation from latency could be a potential therapeutic stratagem for KSHV-associated cancers. Oxidative stress, the clinical hallmark of PEL, is one of the most prominent inducers for KSHV reactivation. Paradoxically, we found that hydrogen peroxide (H2O2) triggers robust cytotoxic effects on KSHV-negative rather than KSHV-positive B lymphoma cells in a dose-dependent manner. Mechanistically, we identified forkhead box protein O1 (FoxO1) and FoxO3 as irrevocable antioxidant defense genes and both of them are upregulated by KSHV latent infection, which is essential for the promoted ROS scavenging in KSHV-positive B lymphoma cells. Pharmacological inhibition or functional knockdown of either FoxO1 or FoxO3 is sufficient to ablate the antioxidant ability and therefore increases the intracellular ROS level that further reverses KSHV from latency to active lytic replication in PEL cells, resulting in tremendous cell death both in vitro and in vivo. Additionally, the elevated level of ROS by inhibiting FoxO proteins further sensitizes PEL cells to ROS-induced apoptosis. Our study therefore demonstrated that the lytic reactivation of KSHV by inhibiting FoxO proteins is a promising therapeutic approach for PEL, which could be further extended to other virus-associated diseases.

Magnetic Microbead-Based Herringbone Chip for Sensitive Detection of Human Immunodeficiency Virus.

The microfluidic chip-based nucleic acid detection method significantly improves the sensitivity since it precisely controls the microfluidic flow in microchannels. Nonetheless, significant challenges still exist in improving the detection efficiency to meet the demand for rapid detection of trace substances. This work provides a novel magnetic herringbone (M-HB) structure in a microfluidic chip, and its advantage in rapid and sensitive detection is verified by taking complementary DNA (cDNA) sequences of human immunodeficiency virus (HIV) detection as an example. The M-HB structure is designed based on controlling the magnetic field distribution in the micrometer scale and is formed by accumulation of magnetic microbeads (MMBs). Hence, M-HB is similar to a nanopore microstructure, which has a higher contact area and probe density. All of the above is conducive to improving sensitivity in microfluidic chips. The M-HB chip is stable and easy to form, which can linearly detect cDNA sequences of HIV quantitatively ranging from 1 to 20 nM with a detection limit of 0.073 nM. Compared to the traditional herringbone structure, this structure is easier to form and release by controlling the magnetic field, which is flexible and helps in further study. Results show that this chip can sensitively detect the cDNA sequences of HIV in blood samples, demonstrating that it is a powerful platform to rapidly and sensitively detect multiple nucleic acid-related viruses of infectious diseases.

Androgen deprivation therapy, neoadjuvant androgen deprivation therapy, and adjuvant androgen deprivation therapy in patients with locally advanced prostate cancer: a multi-center real-world retrospective study.

PURPOSE: Determining the potential benefit of neoadjuvant androgen deprivation therapy (ADT) and adjuvant ADT in patients with locally advanced prostate cancer (LAPC) undergoing complete resection. METHODS: 139 patients diagnosed with cT3-4, or cN+ LAPC in Xiangya Hospital and The First Affiliated Hospital of University of South China from 2010 to 2021 were collected. Cancer-specific survival (CSS) and overall survival (OS) of patients were assessed using Kaplan-Meier and Cox proportional risk analysis. We also analyzed the functional outcomes of two subgroups of patients who underwent radical prostatectomy (RP). RESULTS: Of the 182 patients with cT3-4, or cN+ LAPC, 139 patients (76.4%) were enrolled in the study with a 5-year survival rate of 82.3%. 45 patients (32.4%) received ADT alone, 46 patients (33.1%) received neoadjuvant ADT before surgery, and the remaining 48 patients (34.5%) received surgery with adjuvant ADT. Neoadjuvant ADT before surgery and surgery with adjuvant ADT were associated with significantly improved survival compared with ADT alone. Multivariate Cox models showed that neoadjuvant ADT before surgery (hazard ratio [HR], 0.29; 95% CI 0.13-0.92) or surgery with adjuvant ADT (HR, 0.26; 95% CI 0.16-0.78) was associated with improved CSS compared with ADT alone. Regional lymph node metastasis, positive lymphovascular invasion, and Gleason score 9 + were independent predictors of LAPC CSS and OS. More patients in the neoadjuvant ADT before surgery group achieved final continence status within 12 months after surgery (93.48% v 77.08%). CONCLUSION: CSS and OS were significantly prolonged in cT3-4, or cN+ LAPC patients who received neoadjuvant ADT before surgery and surgery with adjuvant ADT compared to ADT alone.

The haemagglutinin-neuraminidase protein of velogenic Newcastle disease virus enhances viral infection through NF-κB-mediated programmed cell death.

The haemagglutinin-neuraminidase (HN) protein, a vital membrane glycoprotein, plays a pivotal role in the pathogenesis of Newcastle disease virus (NDV). Previously, we demonstrated that a mutation in the HN protein is essential for the enhanced virulence of JS/7/05/Ch, a velogenic variant NDV strain originating from the mesogenic vaccine strain Mukteswar. Here, we explored the effects of the HN protein during viral infection in vitro using three viruses: JS/7/05/Ch, Mukteswar, and an HN-replacement chimeric NDV, JS/MukHN. Through microscopic observation, CCK-8, and LDH release assays, we demonstrated that compared with Mukteswar and JS/MukHN, JS/7/05/Ch intensified the cellular damage and mortality attributed to the mutant HN protein. Furthermore, JS/7/05/Ch induced greater levels of apoptosis, as evidenced by the activation of caspase-3/8/9. Moreover, JS/7/05/Ch promoted autophagy, leading to increased autophagosome formation and autophagic flux. Subsequent pharmacological experiments revealed that inhibition of apoptosis and autophagy significantly impacted virus replication and cell viability in the JS/7/05/Ch-infected group, whereas less significant effects were observed in the other two infected groups. Notably, the mutant HN protein enhanced JS/7/05/Ch-induced apoptosis and autophagy by suppressing NF-κB activation, while it mitigated the effects of NF-κB on NDV infection. Overall, our study offers novel insights into the mechanisms underlying the increased virulence of NDV and serves as a reference for the development of vaccines.

Amino acid mutations PB1-V719M and PA-N444D combined with PB2-627K contribute to the pathogenicity of H7N9 in mice.

H7N9 subtype avian influenza viruses (AIVs) cause 1567 human infections and have high mortality, posing a significant threat to public health. Previously, we reported that two avian-derived H7N9 isolates (A/chicken/Eastern China/JTC4/2013 and A/chicken/Eastern China/JTC11/2013) exhibit different pathogenicities in mice. To understand the genetic basis for the differences in virulence, we constructed a series of mutant viruses based on reverse genetics. We found that the PB2-E627K mutation alone was not sufficient to increase the virulence of H7N9 in mice, despite its ability to enhance polymerase activity in mammalian cells. However, combinations with PB1-V719M and/or PA-N444D mutations significantly enhanced H7N9 virulence. Additionally, these combined mutations augmented polymerase activity, thereby intensifying virus replication, inflammatory cytokine expression, and lung injury, ultimately increasing pathogenicity in mice. Overall, this study revealed that virulence in H7N9 is a polygenic trait and identified novel virulence-related residues (PB2-627K combined with PB1-719M and/or PA-444D) in viral ribonucleoprotein (vRNP) complexes. These findings provide new insights into the molecular mechanisms underlying AIV pathogenesis in mammals, with implications for pandemic preparedness and intervention strategies.

Lack of causal association between epilepsy and dementia: A Mendelian randomization analysis.

OBJECTIVE: Epidemiological studies have reported an association between epilepsy and dementia. However, the causal relationship between epilepsy and the risk of dementia is not clear. We aimed to inspect the causal effect of epilepsy on memory loss and dementia. METHODS: We analyzed summary data of epilepsy, memory loss, and dementia from the genome-wide association study (GWAS) using the two-sample Mendelian randomization (MR) method. We used the estimated odds ratio of memory loss and dementia associated with each of the genetically defined traits to infer evidence for a causal relationship with the following exposures: all epilepsy, focal epilepsy (including focal epilepsy with hippocampal sclerosis, lesion-negative focal epilepsy, and focal epilepsy with other lesions), and genetic generalized epilepsy (including childhood absence epilepsy, generalized tonic-clonic seizures alone, Juvenile absence epilepsy, and Juvenile myoclonic epilepsy). RESULTS: According to the result of MR using the inverse variance weighted method (IVW), we found that genetically predicted epilepsy did not causally increase the risk of memory loss and dementia (p > 0.05). Results of the MR-Egger and weighted median method were consistent with the IVW method. CONCLUSIONS: No evidence has been found to support the notion that epilepsy can result in memory loss and dementia. The associations observed in epidemiological studies could be attributed, in part, to confounding or nongenetic determinants.

Hsa_circ_0000520 suppresses vasculogenic mimicry formation and metastasis in bladder cancer through Lin28a/PTEN/PI3K signaling.

BACKGROUND: Vasculogenic mimicry (VM) is a potential cause of resistance to antiangiogenic therapy and is closely related to the malignant progression of tumors. It has been shown that noncoding RNAs play an important role in the formation of VM in malignant tumors. However, the role of circRNAs in VM of bladder cancer and the regulatory mechanisms are unclear. METHODS: Firstly, hsa_circ_0000520 was identified to have circular character by Sanger sequencing and Rnase R assays. Secondly, the potential clinical value of hsa_circ_0000520 was explored by quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH) of clinical specimens. Thirdly, the role of hsa_circ_0000520 in bladder cancer invasion, migration, and VM formation was examined by in vivo and in vitro experiments. Finally, the regulatory mechanisms of hsa_circ_0000520 in the malignant progression of bladder cancer were elucidated by RNA binding protein immunoprecipitation (RIP), RNA pulldown, co-immunoprecipitation (co-IP), qRT-PCR, Western blot (WB), and fluorescence co-localization. RESULTS: Hsa_circ_0000520 was characterized as a circular RNA and was lowly expressed in bladder cancer compared with the paracancer. Bladder cancer patients with high expression of hsa_circ_0000520 had better survival prognosis. Functionally, hsa_circ_0000520 inhibited bladder cancer invasion, migration, and VM formation. Mechanistically, hsa_circ_0000520 acted as a scaffold to promote binding of UBE2V1/UBC13 to Lin28a, further promoting the ubiquitous degradation of Lin28a, improving PTEN mRNA stability, and inhibiting the phosphorylation of the PI3K/AKT pathway. The formation of hsa_circ_0000520 in bladder cancer was regulated by RNA binding protein QKI. CONCLUSIONS: Hsa_circ_0000520 inhibits metastasis and VM formation in bladder cancer and is a potential target for bladder cancer diagnosis and treatment.

Prolonged exposure to air pollution and risk of acute kidney injury and related mortality: a prospective cohort study based on hospitalized AKI cases and general population controls from the UK Biobank.

BACKGROUND: Previous investigations identified a connection between air pollution and kidney diseases. Nevertheless, there is a lack of comprehensive evidence on the long-term risks posed by air pollution with respect to acute kidney injury (AKI) and AKI-related death. METHODS: This prospective cohort analysis included 414,885 UK Biobank (UKB) participants who did not exhibit AKI at the study's outset. AKI was defined based on ICD-10 codes recorded for hospitalized patients. Cox proportional hazards models were used to assess the association between prolonged exposure to air pollutants (particulate matter with diameters of 2.5 micrometers or less (PM2.5), between 2.5 and 10 micrometers (PM2.5-10), and 10 micrometers or less (PM10), along with nitrogen dioxide (NO2) and nitrogen oxides (NOx)) and the risk of AKI and AKI-related death, adjusting for potential confounders including sex, age, ethnicity, education, income, lifestyle factors, and relevant clinical covariates. Restricted cubic splines were applied to evaluate non-linear dose-response relationships, and stratified analyses were performed to explore potential effect modification across subgroups. RESULTS: Over an average follow-up duration of 11.7 years, 14,983 cases of AKI and 326 cases of AKI-related death were diagnosed. Quartile analysis showed individuals exposed to higher levels of these air pollutants had a significantly higher risk of developing AKI and AKI-related death compared to those in the lowest quartile (all P < 0.05). The RCS curves depicting the relationship between PM2.5, PM2.5-10, PM10, NO2, NOx, and the risk of AKI showed a significant departure from linearity (P for non-linearity < 0.05), while the relationships between PM2.5, NO2, NOx, and the risk of AKI-related death did not exhibit a significant departure from linearity (P for non-linearity > 0.05). Sensitivity analyses confirmed the robustness of our findings. CONCLUSION: Our study reveals a direct association between prolonged air pollution exposure and elevated risks of both AKI and AKI-related death. These findings offer scientific validation for the adoption of environmental and public health measures directed towards the reduction of air pollution. Such initiatives could potentially ease the impact associated with AKI and AKI-related death.

Physical activity experience of patients with hypertension: a systematic review and synthesis of qualitative literature.

BACKGROUND: Hypertension continues to increase in prevalence, and it has become a major cause of increased mortality globally. Physical activity (PA) has been shown to be a first-line treatment for controlling blood pressure. However, participation rates in PA are still poor. Therefore, it's imperative to explore the factors that affect patient PA adherence. METHODS: A synthesis of qualitative research of the PA experience of patients with hypertension was conducted. We systematically searched for qualitative studies published in English from inception to May 2023 in the databases of PubMed, Embase, Web of Science, CINAHL, PsycINFO, and Cochrane Library. The Joanna Briggs Institute tool was used to extract data, and the Capability, Opportunity, Motivation-Behaviour model was used to synthesize data. RESULTS: This qualitative research included 17 studies, identified 85 findings, summarized 9 categories, and finally meta-aggregated 3 synthesized findings, including capabilities of patients with hypertension, PA opportunities and PA motivators. The capabilities included age, other health problems, and PA knowledge and skills. Opportunities included time constraints, environmental factors, physical activity resources, and social support. Motivators included self-efficacy, pursuing physical health, and experience from PA. CONCLUSION: The available evidence contributes to a comprehensive understanding of the barriers and facilitators of PA in patients with hypertension. Most of these barriers can be addressed and improved. When designing and implementing physical activity programs for patients with hypertension, an individualized PA program should first be designed, tailored to the patient's capacity. Secondly, patients should be provided with additional PA resources and enhanced social support. Lastly, patients' motivation can be increased by enhancing their PA experience.

Multi-functional nanozyme-based colorimetric, fluorescence dual-mode assay for Salmonella typhimurium detection in milk.

Rapid and high-sensitive Salmonella detection in milk is important for preventing foodborne disease eruption. To overcome the influence of the complex ingredients in milk on the sensitive detection of Salmonella, a dual-signal reporter red fluorescence nanosphere (RNs)-Pt was designed by combining RNs and Pt nanoparticles. After being equipped with antibodies, the immune RNs-Pt (IRNs-Pt) provide an ultra-strong fluorescence signal when excited by UV light. With the assistance of the H2O2/TMB system, a visible color change appeared that was attributed to the strong peroxidase-like catalytic activity derived from Pt nanoparticles. The IRNs-Pt in conjunction with immune magnetic beads can realize that Salmonella typhimurium (S. typhi) was captured, labeled, and separated effectively from untreated reduced-fat pure milk samples. Under the optimal experimental conditions, with the assay, as low as 50 CFU S. typhi can be converted to detectable fluorescence and absorbance signals within 2 h, suggesting the feasibility of practical application of the assay. Meanwhile, dual-signal modes of quantitative detection were realized. For fluorescence signal detection (emission at 615 nm), the linear correlation between signal intensity and the concentration of S. typhi was Y = 83C-3321 (R2 = 0.9941), ranging from 103 to 105 CFU/mL, while for colorimetric detection (absorbamce at 450 nm), the relationship between signal intensity and the concentration of S. typhi was Y = 2.9logC-10.2 (R2 = 0.9875), ranging from 5 × 103 to 105 CFU/mL. For suspect food contamination by foodborne pathogens, this dual-mode signal readout assay is promising for achieving the aim of convenient preliminary screening and accurate quantification simultaneously.

Nitrogen-bridged Fe-Cu Atomic Pair Sites for Efficient Electrochemical Ammonia Production and Electricity Generation with Zn-NO2 Batteries.

The development of environmentally sustainable and highly efficient technologies for ammonia production is crucial for the future advancement of carbon-neutral energy systems. The nitrite reduction reaction (NO2 RR) for generating NH3 is a promising alternative to the low-efficiency nitrogen reduction reaction (NRR), owing to the low N=O bond energy and high solubility of nitrite. In this study, we designed a highly efficient dual-atom catalyst with Fe-Cu atomic pair sites (termed FeCu DAC), and the as-developed FeCu DAC was able to afford a remarkable NH3 yield of 24,526 µg h-1 mgcat. -1 at -0.6 V, with a Faradaic Efficiency (FE) for NH3 production of 99.88 %. The FeCu DAC also exhibited exceptional catalytic activity and selectivity in a Zn-NO2 battery, achieving a record-breaking power density of 23.6 mW cm-2 and maximum NH3 FE of 92.23 % at 20 mA cm-2 . Theoretical simulation demonstrated that the incorporation of the Cu atom changed the energy of the Fe 3d orbital and lowered the energy barrier, thereby accelerating the NO2 RR. This study not only demonstrates the potential of galvanic nitrite-based cells for expanding the field of Zn-based batteries, but also provides fundamental interpretation for the synergistic effect in highly dispersed dual-atom catalysts.

Establishment and validation of the autophagy-related ceRNA network in irreversible pulpitis.

BACKGROUND: The molecular mechanisms underlying the onset and progression of irreversible pulpitis have been studied for decades. Many studies have indicated a potential correlation between autophagy and this disease. Against the background of the competing endogenous RNA (ceRNA) theory, protein-coding RNA functions are linked with long noncoding RNAs (lncRNAs) and microRNAs (miRNAs). This mechanism has been widely studied in various fields but has rarely been reported in the context of irreversible pulpitis. The hub genes selected under this theory may represent the key to the interaction between autophagy and irreversible pulpitis. RESULTS: Filtering and differential expression analyses of the GSE92681 dataset, which contains data from 7 inflamed and 5 healthy pulp tissue samples, were conducted. The results were intersected with autophagy-related genes (ARGs), and 36 differentially expressed ARGs (DE-ARGs) were identified. Functional enrichment analysis and construction of the protein‒protein interaction (PPI) network of DE-ARGs were performed. Coexpression analysis was conducted between differentially expressed lncRNAs (DElncRNAs) and DE-ARGs, and 151 downregulated and 59 upregulated autophagy-related DElncRNAs (AR-DElncRNAs) were identified. StarBase and multiMiR were then used to predict related microRNAs of AR-DElncRNAs and DE-ARGs, respectively. We established ceRNA networks including 9 hub lncRNAs (HCP5 and AC112496.1 ↑; FENDRR, AC099850.1, ZSWIM8-AS1, DLX6-AS1, LAMTOR5-AS1, TMEM161B-AS1 and AC145207.5 ↓), which were validated by a qRT‒PCR analysis of pulp tissue from patients with irreversible pulpitis. CONCLUSION: We constructed two networks consisting of 9 hub lncRNAs based on the comprehensive identification of autophagy-related ceRNAs. This study may provide novel insights into the interactive relationship between autophagy and irreversible pulpitis and identifies several lncRNAs that may serve as potential biological markers.

Coupling Bifunctional Nanozyme-Mediated Catalytic Signal Amplification and Label-Free SERS with Immunoassays for Ultrasensitive Detection of Pathogens in Milk Samples.

Rapid and sensitive detection of foodborne bacteria is of great significance in guaranteeing food safety and preventing foodborne diseases. A bifunctional Au@Pt core-shell nanozyme with excellent catalytic properties and high surface-enhanced Raman scattering (SERS) activity was developed for the highly sensitive detection of Salmonella typhimurium based on a label-free SERS strategy. The ultrathin Pt shell (about 1 nm) can catalyze Raman-inactive molecules into Raman-active reporters, greatly amplifying the amount of signal molecules. Moreover, the Au core serves as an active SERS substrate to enhance the signal of reporter molecules, further significantly improving the detection sensitivity. Benefiting from the excellent properties, such a bifunctional Au@Pt nanozyme was integrated with a magnetic immunoassay to construct a label-free SERS platform for the highly sensitive detection of S. typhi with a low detection limit of 10 CFU mL-1. Also, the Au@Pt-based SERS platform exhibited excellent selectivity and was successfully utilized for the detection of S. typhi in milk samples by a portable Raman spectrometer. Our demonstration of the bifunctional nanozyme-based SERS strategy provides an efficient pathway to improve the sensitivity of label-free SERS detection of pathogens and holds great promise in food safety, environmental analysis, and other biosensing fields.

Cellular vimentin regulates the infectivity of Newcastle disease virus through targeting of the HN protein.

The haemagglutinin-neuraminidase (HN) protein plays a crucial role in the infectivity and virulence of Newcastle disease virus (NDV). In a previous study, the mutant HN protein was identified as a crucial virulence factor for the velogenic variant NDV strain JS/7/05/Ch, which evolved from the prototypic vaccine strain Mukteswar. Furthermore, macrophages are the main susceptible target cells of NDV. However, the possible involvement of cellular molecules in viral infectivity remains unclear. Herein, we elucidate the crucial role of vimentin, an intermediate filament protein, in regulating NDV infectivity through targeting of the HN protein. Using LC‒MS/MS mass spectrometry and coimmunoprecipitation assays, we identified vimentin as a host protein that differentially interacted with prototypic and mutant HN proteins. Further analysis revealed that the variant NDV strain induced more significant rearrangement of vimentin fibres compared to the prototypic NDV strain and showed an interdependence between vimentin rearrangement and virus replication. Notably, these mutual influences were pronounced in HD11 chicken macrophages. Moreover, vimentin was required for multiple infection processes of the variant NDV strain in HD11 cells, including viral internalization, fusion, and release, while it was not necessary for those of the prototypic NDV strain. Collectively, these findings underscore the pivotal role of vimentin in NDV infection through targeting of the HN protein, providing novel targets for antiviral treatment strategies for NDV.

GmCBP60b Plays Both Positive and Negative Roles in Plant Immunity.

CBP60b (CALMODULIN-BINDING PROTEIN 60b) is a member of the CBP60 transcription factor family. In Arabidopsis, AtCBP60b not only regulates growth and development but also activates the transcriptions in immune responses. So far, CBP60b has only been studied extensively in the model plant Arabidopsis and rarely in crops. In this study, Bean pod mottle virus (BPMV)-mediated gene silencing (BPMV-VIGS) was used to silence GmCBP60b.1/2 in soybean plants. The silencing of GmCBP60b.1/2 resulted in typical autoimmunity, such as dwarfism and enhanced resistance to both Soybean mosaic virus (SMV) and Pseudomonas syringae pv. glycinea (Psg). To further understand the roles of GmCBP60b in immunity and circumvent the recalcitrance of soybean transformation, we generated transgenic tobacco lines that overexpress GmCBP60b.1. The overexpression of GmCBP60b.1 also resulted in autoimmunity, including spontaneous cell death on the leaves, highly induced expression of PATHOGENESIS-RELATED (PR) genes, significantly elevated accumulation of defense hormone salicylic acid (SA), and significantly enhanced resistance to Pst DC3000 (Pseudomonas syrangae pv. tomato DC3000). The transient coexpression of a luciferase reporter gene driven by the promoter of soybean SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (GmSARD1) (ProGmSARD1::LUC), together with GmCBP60b.1 driven by the 35S promoter, led to the activation of the LUC reporter gene, suggesting that GmCBP60b.1 could bind to the core (A/T)AATT motifs within the promoter region of GmSARD1 and, thus, activate the expression of the LUC reporter. Taken together, our results indicate that GmCBP60b.1/2 play both positive and negative regulatory roles in immune responses. These results also suggest that the function of CBP60b is conserved across plant species.

Silencing GmATG7 Leads to Accelerated Senescence and Enhanced Disease Resistance in Soybean.

Autophagy plays a critical role in nutrient recycling/re-utilizing under nutrient deprivation conditions. However, the role of autophagy in soybeans has not been intensively investigated. In this study, the Autophay-related gene 7 (ATG7) gene in soybeans (referred to as GmATG7) was silenced using a virus-induced gene silencing approach mediated by Bean pod mottle virus (BPMV). Our results showed that ATG8 proteins were highly accumulated in the dark-treated leaves of the GmATG7-silenced plants relative to the vector control leaves (BPMV-0), which is indicative of an impaired autophagy pathway. Consistent with the impaired autophagy, the dark-treated GmATG7-silenced leaves displayed an accelerated senescence phenotype, which was not seen on the dark-treated BPMV-0 leaves. In addition, the accumulation levels of both H2O2 and salicylic acid (SA) were significantly induced in the GmATG7-silenced plants compared with the BPMV-0 plants, indicating an activated immunity. Consistently, the GmATG7-silenced plants were more resistant against both Pseudomonas syringae pv. glycinea (Psg) and Soybean mosaic virus (SMV) compared with the BPMV-0 plants. However, the activated immunity in the GmATG7-silenced plant was not dependent upon the activation of MPK3/MPK6. Collectively, our results demonstrated that the function of GmATG7 is indispensable for autophagy in soybeans, and the activated immunity in the GmATG7-silenced plant is a result of impaired autophagy.

MetR is a molecular adaptor for pneumococcal carriage in the healthy upper airway.

Streptococcus pneumoniae resides in the human upper airway as a commensal but also causes pneumonia, bacteremia, meningitis, and otitis media. It remains unclear how pneumococci adapt to nutritional conditions of various host niches. We here show that MetR, a LysR family transcriptional regulator, serves as a molecular adaptor for pneumococcal fitness, particularly in the upper airway. The metR mutant of strain D39 rapidly disappeared from the nasopharynx but was marginally attenuated in the lungs and bloodstream of mice. RNA-seq and ChIP-seq analyses showed that MetR broadly regulates transcription of the genes involved in methionine synthesis and other functions under methionine starvation. Genetic and biochemical analyses confirmed that MetR is essential for the activation of methionine synthesis but not uptake. Co-infection of influenza virus partially restored the colonization defect of the metR mutant. These results strongly suggest that MetR is particularly evolved for pneumococcal carriage in the upper airway of healthy individuals where free methionine is severely limited, but it becomes dispensable where environmental methionine is relatively more abundant (e.g., inflamed upper airway and sterile sites). To the best of our knowledge, MetR represents the first known regulator particularly for pneumococcal carriage in healthy individuals.