Quanhai Pang

Monkeypox (Mpox) is a zoonotic disease that threatens global public health. Different clades of monkeypox virus (MPXV) vary in transmissibility and pathogenicity. In 2023, a Clade Ib MPXV variant emerged in the Democratic Republic of the Congo, continued to spread in parts of Africa, and subsequently spilled over to other regions, posing new challenges for outbreak prevention and control. We established stable mouse models of MPXV Clade Ib infection by intranasally infecting C57BL/6/STAT1^-/-, AGB6 (C57BL/6-Ifngr1^-/-Ifnar1^-/-), C57BL/6, and BALB/c mice. Susceptible strains showed marked body weight loss, high viral loads in tissues, and severe histopathological lesions. RNA-seq analysis of spleens at the early stage of infection showed that differentially expressed genes were mainly enriched in interferon-mediated antiviral pathways and inflammatory cytokine-related pathways, whereas genes associated with adaptive immune responses were downregulated. Comparative analysis showed that MPXV Clade Ib caused more severe disease phenotypes than Clade IIb under the same experimental conditions, which is consistent with reported differences in clinical severity. We established reproducible mouse models for MPXV Clade Ib infection and demonstrated that Clade Ib showed greater replication capacity and pathogenicity than Clade IIb in these models. This study also provides a foundation for subsequent research on the pathogenesis of MPXV and the evaluation of antiviral efficacy.

Background: Abnormal activation of the NRF2-cGAS-STING-NF-κB pathway can trigger an inflammatory cascade in rheumatoid arthritis (RA). Curcumin (CUR), a polyphenolic compound extracted from turmeric, possesses anti-inflammatory activity, but whether it can modulate this pathway to ameliorate RA remains unclear. This study aims to elucidate whether CUR inhibits the inflammatory response in synovial fibroblasts (MH7A) by suppressing the NRF2-cGAS-STING-NF-κB signaling cascade. Methods: An RA inflammatory model was constructed by stimulating MH7A cells with 20 ng/mL tumor necrosis factor (TNF). Groups included a control group, a model group, a methotrexate positive control group [MTX(methotrexate), 10 μmol/L], and curcumin treatment groups at varying concentrations (10–100 μmol/L). Cell viability was assessed using the CCK-8(Cell Counting Kit-8) assay. Cell migration and invasion capabilities were evaluated via scratch wound healing and Transwell assays, respectively. Apoptosis was detected by flow cytometry. mRNA and protein expression levels of NRF2(Nuclear factor erythroid 2-related factor 2), cGAS(cyclic GMP-AMP synthase), STING(stimulator of interferon genes), and NF-κB(nuclear factor kappa-light-chain-enhancer of activated B cells) were measured using qRT-PCR and Western blot, respectively. Protein localization was determined by immunofluorescence. Results: Compared to the model group (TNF-induced), the cell migration rate in the curcumin (CUR) groups was significantly decreased (p < 0.001), with a particularly marked reduction observed at a concentration of 50 μmol/L. Furthermore, as the concentration of curcumin increased, cell invasion capacity showed a significant dose-dependent decline. The apoptosis rate also significantly decreased with increasing curcumin concentrations, demonstrating a clear concentration-dependent effect. Mechanistically, curcumin treatment significantly upregulated the expression of NRF2 and inhibited the activation of its downstream cGAS-STING-NF-κB signaling pathway. Specifically, both mRNA and protein expression levels of NRF2 were markedly elevated (p < 0.001), while the mRNA and protein levels of cGAS, STING, and NF-κB were all significantly reduced (p < 0.001). Conclusions: Curcumin (CUR) can effectively inhibit the inflammatory response of synovial fibroblasts by activating the expression of NRF2 and subsequently suppressing the cGAS-STING-NF-κB signaling pathway. This study provides a new molecular mechanism target for curcumin in the treatment of RA and offers a theoretical basis for the intervention of autoimmune diseases with natural products.

Background: Previous studies have demonstrated that oxidative stress and melanogenesis are regulated by the Wnt/β-catenin signaling pathway. However, the precise mechanism by which the PEDF/Wnt/β-catenin axis modulates apoptosis and melanogenesis remains unclear. Methods: Cell viability and mortality rates were assessed using CCK-8 assays and lactate dehydrogenase (LDH) release assays. Mitochondrial ultrastructural changes were analyzed by transmission electron microscopy (TEM). Changes in the mitochondrial membrane potential (ΔΨm) were assessed using the JC-1 fluorescent probe. The effects of PEDF on protein and gene expression were evaluated by Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR). Results: As the concentration of H ₂ O ₂ increased, the cell survival rate decreased, which activated the Wnt/β-catenin signaling pathway and increased the apoptosis rate and melanin production. PEDF reversed the H ₂ O ₂ -induced decrease in cell viability and increase in mortality rate in Melan-a cells while ameliorating the impairment of the mitochondrial membrane potential. PEDF ameliorated H ₂ O ₂ -induced protein damage and lipid peroxidation and reduced apoptosis in Melan-a cells. PEDF treatment significantly decreased the protein expression levels of β-catenin, Wnt3a, and Dvl2 ( P < 0.05) and reduced the protein levels of Bax and Caspase-3 ( P < 0.01) in H ₂ O ₂ - and BML-284-treated Melan-a cells. Furthermore, PEDF significantly reduced the H ₂ O ₂ - and BML-284-induced increases in the MITF and TYR protein levels ( P < 0.01). Conclusions: These results suggest that PEDF can reduce H ₂ O ₂ -induced oxidative damage and melanin production in Melan-a cells by inhibiting the activation of Wnt/β-catenin signaling pathway activation. These findings provide a theoretical basis for human oxidative stress and pigment deposition-related diseases.

This review aims to summarize the current understanding of the regulatory mechanisms of nuclear factor of activated T cells c4 (NFATc4) in the pathogenesis of metabolic dysfunction-associated fatty liver disease (MAFLD). We focus on the multifaceted roles of NFATc4 in lipid metabolism, oxidative stress, inflammation, and insulin resistance, with the goal of evaluating its potential as a therapeutic target for MAFLD. Emerging evidence indicates that NFATc4 is significantly upregulated in MAFLD patients and animal models. It promotes hepatic steatosis by inhibiting PPARα-mediated fatty acid oxidation, enhances oxidative stress via mitochondrial dysfunction, exacerbates inflammation through cytokine regulation and immune cell activation, and contributes to insulin resistance by modulating adipokine expression. Pharmacological inhibition of NFATc4 has shown protective effects in preclinical models, highlighting its therapeutic potential. NFATc4 serves as a critical transcriptional regulator in the progression of MAFLD, influencing multiple pathological processes through its nuclear translocation and interaction with key metabolic and inflammatory pathways. Targeting NFATc4 may offer a promising strategy for the treatment of MAFLD, though further research is needed to elucidate cell-type-specific mechanisms and develop tissue-specific inhibitors.

Background: Maternal immune modulation and alterations in gut microbiota due to intestinal helminth infections may be passed on to offspring. However, it remains unclear whether these effects can be transferred between maternal mice and their offspring during tissue-dwelling helminth infections. Methods: In this study, we investigated the effect of maternal infection with Echinococcus multilocularis (Emu) on offspring susceptibility to colitis and gut microbiota composition using a dextran sulfate sodium (DSS)-induced colitis model. We performed 16S ribosomal RNA (rRNA) sequencing to analyze the gut microbiota composition and microbial abundance in Emu-infected and control maternal mice, as well as their offspring. Results: We found that the maternal mice infected with Emu exhibited significant resistance to colitis, characterized by increased expression of Foxp3 in colonic tissue. Conversely, this resistance phenotype was not observed in the offspring of Emu-infected maternal mice, as they showed no reduction in colitis severity and demonstrated decreased Foxp3 expression. Furthermore, the gut microbiota of Emu-infected maternal mice underwent significant changes, with an increase in genera such as Rikenella, Rikenellaceae RC9 gut group, Turicibacter, Odoribacter, and Parabacteroides, while Lactobacillus, Staphylococcus, and Bifidobacterium decreased postinfection. By contrast, their offspring exhibited a markedly distinct gut microbiota shift, characterized by significant increases in Candidatus Saccharimonas, Desulfovibrio, Helicobacter, and Odoribacter, alongside significant reductions in Muribaculum and Clostridium sensu stricto 1 when compared with the offspring of naive mice. Conclusions: These findings suggest that the effects of maternal transmission concerning immune regulation and microbiota alterations in response to helminth infections may depend on species-specific factors. Graphical

Nectin cell adhesion molecule 1 (NECTIN1) is a cell adhesion molecule that belongs to the immunoglobulin superfamily. It has been considered the most ubiquitous receptor for herpesviruses. However, in the context of flavivirus infection, its role was previously unknown. In this study, we described an arrayed siRNA screen mainly targeting Ig-like proteins that showed NECTIN1-restricted bovine viral diarrhea virus (BVDV) infection. We demonstrated that the depletion of NECTIN1 could significantly enhance the infection of both biotypes and multiple genotypes of BVDV, including BVDV-1a, -1b, -1c, -1p, -1m, -1v, and -2a. Notably, the IgV of NECTIN1 has emerged as the key domain restricting BVDV infection. Moreover, NECTIN1 inhibited BVDV attachment without exerting a significant influence on BVDV translation or transcription. Furthermore, we demonstrated that both NECTIN1 and CD46 could bind to BVDV E2, while the binding affinity of NECTIN1 for BVDV E2 was greater than that for CD46. We further identified that the BVDV E2 domain DD was a key domain of BVDV interacting with NECTIN1. In addition, we showed that NECTIN1 inhibited infections by classical swine fever virus (CSFV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV), which belong to the Flaviviridae family, but had limited effects on bluetongue virus (BTV), vesicular stomatitis virus (VSV), Akabane virus (AKAV), and Sindbis virus (SINV). Overall, our study has important implications for understanding the entry of BVDV and revealed a novel role for NECTIN1 as a restriction factor that inhibits flavivirus infection. IMPORTANCE: NECTIN1, also known as CD111 or PVRL1, has been recognized as the primary receptor for several alpha herpesviruses, including herpes simplex virus (HSV), pseudorabies virus (PRV), and bovine herpesvirus 1 (BHV-1). However, our study revealed a novel role for NECTIN1 in the virus life cycle by influencing BVDV infection. Contrary to its role as a receptor for alpha herpesviruses, NECTIN1 acts as a restriction factor for BVDV by inhibiting viral attachment via competition with CD46 for binding to the domain DD of BVDV E2. We further revealed that the replication of members of the Flaviviridae family was inhibited by NECTIN1, while the replication of other RNA viruses did not significantly differ. Our results demonstrate that NECTIN1 is a novel factor restricting Flaviviridae family virus replication and highlight the complexity of virus-host interactions and the multifaceted nature of host factors involved in viral infection.

Introduction: Bovine viral diarrhea virus (BVDV), a positive-sense single-stranded RNA virus, causes significant economic losses in the cattle industry. Current diagnostic methods for BVDV exhibit variable sensitivity and specificity, underscoring the need for more rapid and accurate detection approaches. Here, we developed a novel competitive ELISA (cELISA) to detect antibodies against the BVDV E2 protein.Methods and results: We generated three monoclonal antibodies (mAbs)—3E6, 2D5, and 5B9—by immunizing mice with purified BVDV E2 protein expressed in Expi293F cells. Among these, mAb 3E6 displayed superior competitive binding abilities to the E2 protein, enabling effective differentiation between BVDV positive and negative sera. Remarkably, mAb 3E6 exhibited pan-genotypic recognition of various BVDV strains, including BVDV-1a, -1b, -1c, -1m, -1p, -1v, and -2a, while showing no cross-reactivity with the classical swine fever virus (CSFV). Computational modeling using AlphaFold 3 identified domain B of the E2 protein as the primary binding site for mAb 3E6. Building upon these findings, we established a cELISA employing mAb 3E6 and recombinant E2 protein. Receiver-operating characteristic (ROC) analysis revealed outstanding diagnostic performance, achieving a sensitivity of 99.26% and specificity of 98.99%. Further tests confirmed the cELISA's specificity for detecting BVDV-specific antibodies, with no cross-reactivity with antisera from animals infected or immunized against BCoV, BHV-1, BRV, AKAV, LSDV, BLV, and CSFV. Consistency was observed between results from the BVDV E2 cELISA and traditional virus neutralization test (VNT), demonstrating high sensitivity for monitoring antibody dynamics. In performance evaluations, the established cELISA exhibited high concordance with VNT in assessing 160 vaccinated sera and 190 clinical samples.Discussion: The BVDV E2 cELISA, utilizing mAb 3E6 to target domain B of the BVDV E2 protein, represents a reliable and effective serological diagnostic tool for the detection of antibodies against both BVDV-1 and BVDV-2. This methodology holds significant promise for applications in clinical diagnosis and the evaluation of vaccine efficacy.

Objective: Coat color is an important characteristic and economic trait in domestic sheep. In this study, we explored the potential mechanisms and the signaling pathways involved in coat color regulation for sheep.Methods: Isobaric tags for relative and absolute quantification (iTRAQ) technology was used to catalog global protein expression profiles in skin of sheep with black versus white coat color. Immunofluorescence was used to observe the expression localization of differential protein. Western blot and quantitative real time polymerase chain reaction (qRT-PCR) were used to evaluate their role in the coat color formation of sheep.Results: A total of 136 differential proteins were obtained in different coat colors, including 101 up-regulated and 35 down-regulated. Pigmentation function entries were enriched through gene ontology annotation. Tyrosine metabolism and platelet activation signaling pathway were extracted by Kyoto encyclopedia of genes and genomes analysis. Apolipoprotein A-1 (APOA1) and fibrinogen alpha chain (FGA) were found to be critical differential proteins by the interaction of differential proteins in the direct-interaction network diagram. Strikingly, twenty candidate differential proteins were screened, from which beta-actin (ACTB) protein showed higher expression in white sheep skin, while albumin (ALB), APOA1, MAOA (amine oxidase) and FGA proteins showed higher expression in black sheep skin, which was validated by immunofluorescence, western blot, and qRT-PCR.Conclusion: This study identified several novel proteins that may be involved in the coat color formation of sheep. The white and black sheep skin proteome profiles obtained provide a valuable resource for future research to understand the network of protein expression controlling skin physiology and melanogenesis in sheep.

Background: Salmonella Enteritidis is a zoonotic pathogen and poses a substantial risk to human health, as well as significant financial losses to the livestock and poultry industries. It is currently urgent to identify alternatives to antibiotic treatment. Results: In this study, we explored the influence of Puerarin on the immunological response, intestinal flora, serum metabolome, and growth performance of chicks infected with Salmonella Enteritidis. Chicks were weighed at specific time points and the average daily gain (ADG) was calculated. Serum, intestinal, and cecal content samples were collected on days 10 and 17. The results showed that 100 mg/kg of Puerarin significantly suppressed inflammation and enhanced immune function. Metabolomic analysis showed significant differences in serum metabolites after Puerarin treatment and suggested that Puerarin may regulate abnormal amino acid and lipid metabolism after Salmonella Enteritidis infection through the autophagic and ABC transporter pathways. In addition, Puerarin suppressed Salmonella Enteritidis-induced intestinal flora dysbiosis through modulation of the microbial community structures (increased Lactobacillus, Faecalibacterium, and Subdoligranulum), as demonstrated by 16S rRNA analysis. Conclusions: In conclusion, Puerarin can improve growth performance in chicks, suppress the inflammatory response in vivo, enhance immunity, and regulate lipid and amino acid metabolism and the intestinal flora.