Research on Point Cloud Acquisition and Calibration of Deep Hole Inner Surfaces Based on Collimated Ring Laser Beams.

In this study, a ring light point cloud calibration technique based on collimated laser beams is developed, aiming to reduce errors caused by the position and attitude changes of traditional ring light measurement devices. This article details the generation mechanism of the ring beam and the principle of deep hole measurement. It introduces the collimated beam as a reference, building on traditional ring light measurement devices, to achieve the synchronous acquisition of the ring beam and collimated spot images by an industrial camera. The Steger algorithm is employed to accurately extract the coordinates of the point cloud contours of both the ring beam and the collimated spot. By analyzing the shape and position changes of the collimated spot contour, the spatial position and attitude of the measuring device are precisely determined. This technique is applied to the 3D reconstruction of the inner surface of deep holes, ensuring the accurate restoration of the spatial positional attitude of the ring beam by incorporating the spatial positional attitude parameters of the measuring device to precisely calibrate the cross-sectional point cloud coordinates. Experimental results with ring gauges and deep hole workpieces demonstrate that this technique effectively reduces the percentage of point cloud data outside the tolerance range, and improves the accuracy of the 3D reconstruction model by 6.287%, thereby verifying the accuracy and practicality of this technique.

Elevation of IL-8 secretion induced by PEDV infection via NF-κB signaling pathway.

Porcine epidemic diarrhea virus (PEDV) is associated with severe enteritis, which contributes to high mortality in piglets. The aim of this study was to describe molecular mechanisms associated with proinflammatory cytokine(s) production during PEDV infection. We showed that infection of porcine intestine epithelial cell clone J2 (IPEC-J2) with PEDV induces a gradual increase in interleukin 8 (IL-8) production at different time points, as well as infection of Vero E6 with PEDV. The secretion of IL-8 in these two cell lines infected with PEDV is related to the activation of NF-κB. Furthermore, the cells expressing PEDV M or E protein can induce the upregulation of IL-8. These findings suggest that the IL-8 production can be the initiator of inflammatory response by the host cells upon PEDV infection.

Identification of two novel B-cell epitopes located on the spike protein of swine acute diarrhea syndrome coronavirus.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an emerging alpha-coronavirus that causes diarrhea in piglets and results in serious economic losses. During SADS-CoV infection, the spike protein (S) serves as a crucial structural component of the virion, interacting with receptors and eliciting the production of neutralizing antibodies. Due to the potential risk of zoonotic transmission of SADS-CoV, the identification and screening of epitopes on the S glycoproteins will be crucial for development of sensitive and specific diagnostic tools. In this study, we immunized BALB/c mice with recombinant SADS-CoV S trimer protein and generated two S1-specific monoclonal antibodies (mAbs): 8D6 and 6E9, which recognized different linear B-cell epitopes. The minimal fragment recognized by mAb 8D6 was mapped to 311NPDQRD316, the minimal fragment recognized by mAb 6E9 was mapped to 492ARFVDRL498. Homology analysis of the regions corresponding to 13 typical strains of different SADS-CoV subtypes showed high conservation of these two epitopes. These findings contribute to a deeper understanding of the structure of the SADS-CoV S protein, which is valuable for vaccine design and holds potential for developing diagnostic methods to detect SADS-CoV.

Genome-Wide Identification and Expression Analysis of ADK Gene Family Members in Cotton under Abiotic Stress.

Adenosine kinase (ADK) is a key enzyme widely distributed in plants, playing an important role in maintaining cellular energy homeostasis and regulating plant growth, development, and responses to environmental stresses. However, research on ADK genes in cotton (Gossypium hirsutum), an economically significant crop, has been limited. This study identified 92 ADK genes from four cotton species (G. arboreum, G. raimondii, G. hirsutum, and G. barbadense) using HMMER and Local BLASTP methods and classified them into six groups. Chromosomal localization revealed a random distribution of ADK genes in G. hirsutum, with 13 genes located on the At subgenome and 14 genes on the Dt subgenome. Gene structure analysis showed consistency in exon-intron organization within subgroups, while conserved motif analysis identified subgroup-specific motifs, indicating functional diversity. Synteny and collinearity mapping analysis revealed that the primary expansion mechanisms of the ADK gene family in cotton are polyploidy and segmental duplication. Cis-regulatory elements in GhADK promoters were classified into light response, hormone response, developmental regulation, and stress response. We also analyzed the expression patterns of GhADK genes under a low temperature (4 °C) and drought conditions. Most GhADK genes responded to cold stress with different expression patterns, indicating their roles in rapid response and long-term cold adaptation. Under drought stress, expression patterns varied, with some genes showing sustained high expression levels. The qRT-PCR validation of transcriptomic data confirmed the stress-induced expression patterns of selected GhADK genes. Functional analysis through the VIGS silencing of GhADK25 demonstrated its importance in cold and drought stress responses, with silencing resulting in poor growth under stress, highlighting its significance in stress tolerance. This study provides a basis for further understanding the evolutionary relationships and functions of the cotton ADK gene family.

Correction: Liu et al. Cholesterol 25-Hydroxylase Suppresses Swine Acute Diarrhea Syndrome Coronavirus Infection by Blocking Spike Protein-Mediated Membrane Fusion. Viruses 2023, 15, 2406.

In the original publication [...].

Establishment of a diagnostic model of endometriosis based on disulfidptosis-related genes.

OBJECTIVES: We aimed to establish a diagnostic model of endometriosis (EM) based on disulfidptosis-related genes (DRGs). MATERIALS AND METHODS: The mRNA expression data of EM were downloaded from the gene expression omnibus database and subjected to differential analysis, and co-expression analysis was performed based on 10 disulfidptosis genes to acquire DRGs. The differentially expressed DRGs were subjected to biofunctional analysis. Lasso analysis and support vector machine-recursive feature elimination (SVM-RFE) analysis were employed to extract the intersection of feature genes as biomarkers, and the diagnostic values of biomarkers for EM were evaluated based on receiver operating characteristic curves. The correlations between biomarkers and the immune microenvironment were assessed by Pearson analysis of biomarkers and immune cell infiltration levels. RESULTS: Transforming growth factor ß stimulated protein clone 22 domain family member 4 (TSC22D4), and F-box/SPRY domain-containing protein 1 (FBXO45) worked as the diagnostic classifiers in EM, with an obvious decrease in FBXO45 expression and an evident increase in TSC22D4 expression. The areas under the curves of FBXO45 and TSC22D4 were 0.752 and 0.706, respectively, and the area of FBXO45 combined with TSC22D4 reached 0.865, suggesting that TSC22D4 and FBXO45 had high predictive values. The diagnostic markers were closely correlated with immune cell infiltration. CONCLUSION: The diagnostic markers constructed based on disulfidptosis are good predictors for EM, which have close correlations with EM.

Dental caries status and related factors among 5-year-old children in Shanghai.

BACKGROUND: Dental caries in young children is a difficult global oral health problem. In the last decade, China has put a great deal of effort into reducing the prevalence of dental caries. This study, which is part of the China Population Chronic Disease and Nutrition Surveillance 2021, aimed to investigate the prevalence of dental caries among children aged 5 in Shanghai, China, and its associated factors. METHODS: A total of 1281 children aged 5 years from 6 districts in Shanghai were selected by a stratified sampling method. The survey consisted of an oral health questionnaire and an oral health examination. The questionnaire included questions on oral health knowledge, attitudes, and behaviours. The oral health examination used WHO standards. After screening, the data were input and analysed. Chi-square tests and logistic regression analyses were used to study the relevant factors affecting dental caries. RESULTS: The prevalence of dental caries among 1281 children was 51.0%, the dmft index score was 2.46, the Significant Caries Index (SiC) score was 6.39, and the SiC10 score was 10.35. Dental caries experience was related to the frequency of sweet drink consumption, the age of starting tooth brushing, eating habits after brushing, whether the children had received an oral examination provided by the government (p < 0.05), and the mother's education level but was not related to sex, the use of fluoride toothpaste, the frequency of brushing, whether the parents assisted brushing, or the frequency of flossing (p > 0.05). Logistic regression analysis showed that the region of residence, eating after brushing and the age of starting brushing were associated with dental caries. CONCLUSIONS: Dental caries remained prevalent among 5-year-old children in Shanghai, China. Prevention strategies that target the associated factors including region of residence, eating after brushing, and the age of starting brushing should be considered.

Swine acute diarrhea syndrome coronavirus nucleocapsid protein antagonizes the IFN response through inhibiting TRIM25 oligomerization and functional activation of RIG-I/TRIM25.

Swine acute diarrhea syndrome coronavirus (SADS-CoV), an emerging Alpha-coronavirus, brings huge economic loss in swine industry. Interferons (IFNs) participate in a frontline antiviral defense mechanism triggering the activation of numerous downstream antiviral genes. Here, we demonstrated that TRIM25 overexpression significantly inhibited SADS-CoV replication, whereas TRIM25 deficiency markedly increased viral yield. We found that SADS-CoV N protein suppressed interferon-beta (IFN-ß) production induced by Sendai virus (SeV) or poly(I:C). Moreover, we determined that SADS-CoV N protein interacted with RIG-I N-terminal two caspase activation and recruitment domains (2CARDs) and TRIM25 coiled-coil dimerization (CCD) domain. The interaction of SADS-CoV N protein with RIG-I and TRIM25 caused TRIM25 multimerization inhibition, the RIG-I-TRIM25 interaction disruption, and consequent the IRF3 and TBK1 phosphorylation impediment. Overexpression of SADS-CoV N protein facilitated the replication of VSV-GFP by suppressing IFN-ß production. Our results demonstrate that SADS-CoV N suppresses the host IFN response, thus highlighting the significant involvement of TRIM25 in regulating antiviral immune defenses.

Rotavirus infection inhibits SLA-I expression on the cell surface by degrading ß2 M via ERAD-proteasome pathway.

Group A Rotavirus (RVA) is a major cause of diarrhea in infants and piglets. ß2-microglobulin (ß2 M), encoded by the B2M gene, serves as a crucial subunit of the major histocompatibility complex class I (MHC-I) molecules. ß2 M is indispensable for the transport of MHC-I to the cell membrane. MHC-I, also known as swine leukocyte antigen class I (SLA-I) in pigs, presents viral antigens to the cell surface. In this study, RVA infection down-regulated ß2 M expression in both porcine intestinal epithelial cells-J2 (IPEC-J2) and MA-104 cells. RVA infection did not down-regulate the mRNA level of the B2M gene, indicating that the down-regulation of ß2 M occurred on the protein level. Mechanismly, RVA infection triggered ß2 M aggregation in the endoplasmic reticulum (ER) and enhanced the Lys48 (K48)-linked ubiquitination of ß2 M, leading to the degradation of ß2 M through ERAD-proteasome pathway. Furthermore, we found that RVA infection significantly impeded the level of SLA-I on the surface, and the overexpression of ß2 M could recover its expression. In this study, our study demonstrated that RVA infection degrades ß2 M via ERAD-proteasome pathway, consequently hampering SLA-I expression on the cell surface. This study would enhance the understanding of the mechanism of how RVA infection induces immune escape.

The Role of Long Noncoding RNA Negative Regulator of Interferon Response in the Regulation of Hantaan Virus Infection.

Hantaan virus (HTNV) is prevalent in Eurasia. It causes hemorrhagic fever with renal syndrome (HFRS). Long noncoding RNAs (lncRNAs) play key roles in regulating innate immunity. Among these, lncRNA negative regulator of interferon response (NRIR) was reported as an inhibitor of several interferon (IFN)-stimulated genes. Our results showed that: NRIR expression was upregulated by HTNV infection in a type I IFN-dependent manner. The expression of NRIR in CD14+ monocytes from HFRS patients in acute phase was significantly higher than that in convalescent phase and healthy controls. HTNV infection in some HTNV-compatible cells was promoted by NRIR. NRIR negatively regulated innate immunity, especially IFITM3 expression. Localized in the nucleus, NRIR bound with HNRNPC, and knockdown of HNRNPC significantly weakened the effect of NRIR in promoting HTNV infection and restored IFITM3 expression. These results indicated that NRIR regulates the innate immune response against HTNV infection possibly through its interaction with HNRNPC and its influence on IFITM3.

NLRP1 restricts porcine deltacoronavirus infection via IL-11 inhibiting the phosphorylation of the ERK signaling pathway.

Continuously emerging highly pathogenic coronaviruses remain a major threat to human and animal health. Porcine deltacoronavirus (PDCoV) is a newly emerging enterotropic swine coronavirus that causes large-scale outbreaks of severe diarrhea disease in piglets. Unlike other porcine coronaviruses, PDCoV has a wide range of species tissue tropism, including primary human cells, which poses a significant risk of cross-species transmission. Nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain-containing 1 (NLRP1) has a key role in linking host innate immunity to microbes and the regulation of inflammatory pathways. We now report a role for NLRP1 in the control of PDCoV infection. Overexpression of NLRP1 remarkably suppressed PDCoV infection, whereas knockout of NLRP1 led to a significant increase in PDCoV replication. A mechanistic study revealed that NLRP1 suppressed PDCoV replication in cells by upregulating IL-11 expression, which in turn inhibited the phosphorylation of the ERK signaling pathway. Furthermore, the ERK phosphorylation inhibitor U0126 effectively hindered PDCoV replication in pigs. Together, our results demonstrated that NLRP1 exerted an anti-PDCoV effect by IL-11-mediated inhibition of the phosphorylation of the ERK signaling pathway, providing a novel antiviral signal axis of NLRP1-IL-11-ERK. This study expands our understanding of the regulatory network of NLRP1 in the host defense against virus infection and provides a new insight into the treatment of coronaviruses and the development of corresponding drugs.IMPORTANCECoronavirus, which mainly infects gastrointestinal and respiratory epithelial cells in vivo, poses a huge threat to both humans and animals. Although porcine deltacoronavirus (PDCoV) is known to primarily cause fatal diarrhea in piglets, reports detected in plasma samples from Haitian children emphasize the potential risk of animal-to-human spillover. Finding effective therapeutics against coronaviruses is crucial for controlling viral infection. Nucleotide-binding oligomerization-like receptor (NLR) family pyrin domain-containing 1 (NLRP1), a key regulatory factor in the innate immune system, is highly expressed in epithelial cells and associated with the pathogenesis of viruses. We demonstrate here that NLRP1 inhibits the infection of the intestinal coronavirus PDCoV through IL-11-mediated phosphorylation inhibition of the ERK signaling pathway. Furthermore, the ERK phosphorylation inhibitor can control the infection of PDCoV in pigs. Our study emphasizes the importance of NLRP1 as an immune regulatory factor and may open up new avenues for the treatment of coronavirus infection.

Case report: A lung squamous cell carcinoma patient with a rare EGFR G719X mutation and high PD-L1 expression showed a good response to anti-PD1 therapy.

Lung cancer treatment has transitioned fully into the era of immunotherapy, yielding substantial improvements in survival rate for patients with advanced non-small cell lung cancer (NSCLC). In this report, we present a case featuring a rare epidermal growth factor receptor (EGFR) mutation accompanied by high programmed death-ligand 1 (PD-L1) expression, demonstrating remarkable therapeutic efficacy through a combination of immunotherapy and chemotherapy. A 77-year-old male with no family history of cancer suffered from upper abdominal pain for more than half months in August 2020 and was diagnosed with stage IV (cT3N3M1c) lung squamous cell carcinoma (LUSC) harboring both a rare EGFR p.G719C mutation and high expression of PD-L1 (tumor proportion score [TPS] = 90%). Treatment with the second-generation targeted therapy drug Afatinib was initiated on September 25, 2020. However, resistance ensued after 1.5 months of treatment. On November 17, 2020, immunotherapy was combined with chemotherapy (Sintilimab + Albumin-bound paclitaxel + Cisplatin), and a CT scan conducted three months later revealed significant tumor regression with a favorable therapeutic effect. Subsequently, the patient received one year of maintenance therapy with Sintilimab, with follow-up CT scans demonstrating subtle tumor shrinkage (stable disease). This case provides evidence for the feasibility and efficacy of immunotherapy combined with chemotherapy in the treatment of EGFR-mutated and PD-L1 highly expressed LUSC.

MAD2L2, a key regulator in ovarian cancer and promoting tumor progression.

Ovarian cancer (OVCA), a prevalent gynecological malignancy, ranks as the fourth most common cancer among women. Mitotic Arrest Deficient 2 Like 2 (MAD2L2), a chromatin-binding protein and a component of DNA polymerase ζ, has been previously identified as an inhibitor of tumor growth in colorectal cancer. However, the roles of MAD2L2 in OVCA, including its expression, impact, and prognostic significance, remain unclear. We employed bioinformatics tools, Cox Regression analysis, and in vitro cell experiments to investigate its biological functions. Our findings reveal that MAD2L2 typically undergoes genomic alterations, such as amplifications and deep deletions. Moreover, we observed an overexpression of MAD2L2 mRNA in OVCA patients, correlating with reduced survival rates, particularly in those with Grade IV tumors. Furthermore, analysis of mRNA biofunctions indicated that MAD2L2 is predominantly localized in the organellar ribosome, engaging mainly in NADH dehydrogenase activity. This was deduced from the results of gene ontology enrichment analysis, which also identified its role as a structural constituent in mitochondrial translation elongation. These findings were corroborated by KEGG pathway analysis, further revealing MAD2L2's involvement in tumor metabolism and the cell death process. Notably, MAD2L2 protein expression showed significant associations with various immune cells, including CD4+T cells, CD8+T cells, B cells, natural killer cells, and Myeloid dendritic cells. Additionally, elevated levels of MAD2L2 were found to enhance cell proliferation and migration in OVCA cells. The upregulation of MAD2L2 also appears to inhibit the ferroptosis process, coinciding with increased mTOR signaling activity in these cells. Our study identifies MAD2L2 as a novel regulator in ovarian tumor progression and offers new insights for treating OVCA.

A novel antigenic epitope identified on the accessory protein NS6 of porcine deltacoronavirus.

Porcine deltacoronavirus (PDCoV) is a novel enteric coronavirus that can cause vomiting, watery diarrhea in pigs and the death of piglets. The open reading frame (ORF) 5 is one of the accessory genes in PDCoV genome and encodes an accessory protein NS6. To date, the function of NS6 is still unclear. In this study, the recombinant NS6 was successfully expressed in prokaryotic expression system and purified. To prepare monoclonal antibody (mAb), six-week-old female BALB/c mice were primed subcutaneously with purified NS6. A novel mouse mAb against NS6 was obtained and designated as 3D5. The isotype of 3D5 is IgG2b with kappa (κ) light chain. 3D5 can specifically recognizes the natural NS6 in swine testis (ST) cells infected with PDCoV and expressed NS6 in human embryonic kidney 293T (HEK 293T) cells transfected with mammalian vector. The minimal linear B cell epitope recognised by 3D5 on NS6 was 25VPELIDPLVK34 determined by peptide scanning and named EP-3D5. The sequence of EP-3D5 is completely conserved among PDCoV strains. Moreover, six to nine residues of EP-3D5 were identified to be conserved in non-PDCoV strains. These results provide valuable insights into the antigenic structure and function of NS6 in virus pathogenesis, and aid for the development of PDCoV epitope-associated diagnostics and vaccine design.

The efficacy of glyceryl trinitrate for acute intracerebral hemorrhage: A systematic review and meta-analysis.

Current research on the effects of glyceryl trinitrate (GTN) on the lowering of elevated blood pressure (BP) among patients with acute intracerebral hemorrhage (AIH) has not been highly emphasized. The aim of this meta-analysis is to examine the effects of GTN in patients with acute stroke. The lowering of BP was the primary outcome measure in patients treated with GTN compared to no-GTN treatment. A meta-analysis was performed to evaluate the efficacy of GTN in lowering BPs and analyze the outcomes of GTN treatment. Appropriate articles were searched using PubMed, Taylor & Francis Online, Cochrane, Scopus, ScienceDirect, Wiley Online Library, and Springer, with the use of appropriate keywords as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Out of 13 articles eligible for this study, 7 studies qualified for the meta-analysis by meeting the inclusion criteria. The PRISMA guidelines and the recommendations of Cochrane Collaboration were followed when conducting this meta-analysis. After subgroup analysis, differences between patients treated with GTN and without GTN were analyzed. The lowering of BP resulted in improved functional outcomes in patients treated with GTN. This meta-analysis showed differences between the 2 groups, with a risk ratio (RR) of 1.01 (95% confidence interval (95% CI): 0.92-10.07, p = 0.30, I2 = 18%). There was a significant improvement in outcome measures in patients treated with GTN by lowering elevated BP after acute stroke.

IFITM3 restricts porcine deltacoronavirus infection by targeting its Spike protein.

The discovery of antiviral molecules is crucial for controlling porcine deltacoronavirus (PDCoV). Previous studies have provided evidence that the IFN-inducible transmembrane protein 3 (IFITM3), which is coded by an interferon-stimulated gene, prevents the infections of a number of enveloped viruses. Nevertheless, the involvement of IFITM3 in PDCoV infection remains unexplored. In this study, it was observed that the overexpression of IFITM3 successfully restrictes the infection of PDCoV in cell cultures. Conversely, the suppression of IFITM3 facilitates the infection of PDCoV in IPI-2I and IPEC-J2 cells. Further studies revealed that IFITM3 limits the attachment phase of viral infection by interacting with the S1 subunit of the PDCoV Spike (S) protein. In addition, IFITM3 is verified as a member of the CD225 family, the GxxxG conserved motif of this family is important for it to limit PDCoV infection. In summary, this study reveals the mechanism of IFITM3 as an antiviral molecule to inhibit PDCoV infection, and also provides theoretical supports for screening effective anti-PDCoV drugs.

Regulatory mechanism of GPER in the invasion and migration of ectopic endometrial stromal cells in endometriosis.

Endometriosis (EMS) is a chronic inflammatory disorder of high incidence that causes serious reproductive consequences. High estrogen production is a consistently observed endocrine feature of EMS. The present study aims to probe the molecular mechanism of G protein-coupled estrogen receptor 1 (GPER) in the invasion and migration of ectopic endometrial stromal cells (Ect-ESCs) and provides a new rationale for EMS treatment. Eutopic and ectopic endometrial tissues were collected from 41 EMS patients, and primary ESCs were separated. GPER, miR-16-5p, and miR-103a-3p levels in cells and tissues were determined by qRT-PCR or Western blot assay. Cell viability, proliferation, invasion, and migration were evaluated by CCK-8, colony formation, and Transwell assays. The upstream miRNAs of GPER were predicted by databases, and dual-luciferase assay was performed to validate the binding of miR-16-5p and miR-103a-3p to GPER 3'UTR. GPER was highly expressed in EMS tissues and Ect-ESCs. Inhibition of GPER mitigated the proliferation, invasion, and migration of Ect-ESCs. GPER was regulated by miR-16-5p and miR-103a-3p. Overexpression of miR-16-5p and miR-103a-3p negatively regulated GPER expression and inhibited the invasion and migration of Ect-ESC. In conclusion, GPER promoted the invasion and migration of Ect-ESCs, which can be reversed by upstream miR-16-5p and miR-103a-3p.

Isolation, characterization, and phylogenetic analysis of two new porcine parvovirus 1 isolates from Northern China.

Porcine parvovirus (PPV) is a pathogen of infectious reproductive disease, which can cause stillbirth, mummification, embryo death, and infertility (SMEDI) syndrome in pigs. The objective of this study was to gain new insights into the evolution and phylogeny of the PPV1 genome. In this study, we isolated two new PPV1 (HLJ202108-Y and SDLC202109) from northern China and sequenced their whole genomes. The new isolates were found to have three amino acid substitutions (K195R, K562R, and S578P) in nonstructural protein 1. The VP2 amino acid site contained nine nonsynonymous substitutions, including six substitutions of the Kresse strain corresponding to the NADL-2 strain and three substitutions of A414S, S436T, and N555K. Genetic evolution analysis was conducted on 107 reference sequences available in the GenBank database, and 4-5 PPV1 taxa were defined. The new isolates were in the same phylogenetic cluster as strain 27a. The changes in the cluster, specifically marker amino acids, and their potential role in enhancing pathogenicity are discussed in this study. Furthermore, the evolutionary tree map results showed that the strains in China were evolving in two directions: one was becoming increasingly similar to early NADL-2 strains, while the other was evolving toward 27a-like strains. We also compared the proliferation ability of the isolated strains in susceptible cells by analyzing the multistep growth curves. The results showed that the virulence titer of the mutant strain was high. In summary, this study introduced the latest changes in PPV and discussed the virus characteristics that were considered to affect virulence.

Cholesterol 25-Hydroxylase Suppresses Swine Acute Diarrhea Syndrome Coronavirus Infection by Blocking Spike Protein-Mediated Membrane Fusion.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an emerging porcine intestinal coronavirus that can cause acute diarrhea, vomiting, rapid weight loss, and high mortality in newborn piglets. Cholesterol 25-hydroxylase (CH25H) is a molecular mediator of innate antiviral immunity and converts cholesterol to 25-hydroxycholesterol (25HC). Previous studies have reported that CH25H and 25HC have an antiviral effect against multiple viruses. However, the interplay between SADS-CoV infection and CH25H or 25HC is still uncertain. Here, we found that CH25H and its enzymatic product 25HC restrained SADS-CoV replication by blocking membrane fusion. Our results show that CH25H was upregulated by SADS-CoV infection in vitro and in vivo, and that it was an IFN-stimulated gene in porcine ileum epithelial cells. Moreover, CH25H and CH25H mutants lacking catalytic activity can inhibit SADS-CoV replication. Furthermore, 25HC significantly suppressed SADS-CoV infection by inhibiting virus entry. Notably, we confirmed that CH25H and 25HC blocked SADS-CoV spike protein-mediated membrane fusion. Our data provide a possible antiviral therapy against SADS-CoV and other conceivable emerging coronaviruses in the future.

Broad antagonism of coronaviruses nsp5 to evade the host antiviral responses by cleaving POLDIP3.

Coronaviruses (CoVs) are a family of the largest RNA viruses that typically cause respiratory, enteric, and hepatic diseases in animals and humans, imposing great threats to the public safety and animal health. Porcine deltacoronavirus (PDCoV), a newly emerging enteropathogenic coronavirus, causes severe diarrhea in suckling piglets all over the world and poses potential risks of cross-species transmission. Here, we use PDCoV as a model of CoVs to illustrate the reciprocal regulation between CoVs infection and host antiviral responses. In this study, downregulation of DNA polymerase delta interacting protein 3 (POLDIP3) was confirmed in PDCoV infected IPEC-J2 cells by isobaric tags for relative and absolute quantification (iTRAQ) and Western blotting analysis. Overexpression of POLDIP3 inhibits PDCoV infection, whereas POLDIP3 knockout (POLDIP3-/-) by CRISPR-Cas9 editing significantly promotes PDCoV infection, indicating POLDIP3 as a novel antiviral regulator against PDCoV infection. Surprisingly, an antagonistic strategy was revealed that PDCoV encoded nonstructural protein 5 (nsp5) was responsible for POLDIP3 reduction via its 3C-like protease cleavage of POLDIP3 at the glutamine acid 176 (Q176), facilitating PDCoV infection due to the loss of antiviral effects of the cleaved fragments. Consistent with the obtained data in IPEC-J2 cell model in vitro, POLDIP3 reduction by cleavage was also corroborated in PDCoV infected-SPF piglets in vivo. Collectively, we unveiled a new antagonistic strategy evolved by PDCoV to counteract antiviral innate immunity by nsp5-mediated POLDIP3 cleavage, eventually ensuring productive virus replication. Importantly, we further demonstrated that nsp5s from PEDV and TGEV harbor the conserved function to cleave porcine POLDIP3 at the Q176 to despair POLDIP3-mediated antiviral effects. In addition, nsp5 from SARS-CoV-2 also cleaves human POLDIP3. Therefore, we speculate that coronaviruses employ similar POLDIP3 cleavage mechanisms mediated by nsp5 to antagonize the host antiviral responses to sustain efficient virus infection.