Seneca valley virus 3C protease blocks EphA2-Mediated mTOR activation to facilitate viral replication.

The Seneca Valley virus (SVV) is a recently discovered porcine pathogen that causes vesicular diseases and poses a significant threat to the pig industry worldwide. Erythropoietin-producing hepatoma receptor A2 (EphA2) is involved in the activation of the AKT/mTOR signaling pathway, which is involved in autophagy. However, the regulatory relationship between SVV and EphA2 remains unclear. In this study, we demonstrated that EphA2 is proteolysed in SVV-infected BHK-21 and PK-15 cells. Overexpression of EphA2 significantly inhibited SVV replication, as evidenced by decreased viral protein expression, viral titers, and viral load, suggesting an antiviral function of EphA2. Subsequently, viral proteins involved in the proteolysis of EphA2 were screened, and the SVV 3C protease (3Cpro) was found to be responsible for this cleavage, depending on its protease activity. However, the protease activity sites of 3Cpro did not affect the interactions between 3Cpro and EphA2. We further determined that EphA2 overexpression inhibited autophagy by activating the mTOR pathway and suppressing SVV replication. Taken together, these results indicate that SVV 3Cpro targets EphA2 for cleavage to impair its EphA2-mediated antiviral activity and emphasize the potential of the molecular interactions involved in developing antiviral strategies against SVV infection.

WET-UNet: Wavelet integrated efficient transformer networks for nasopharyngeal carcinoma tumor segmentation.

Nasopharyngeal carcinoma is a malignant tumor that occurs in the epithelium and mucosal glands of the nasopharynx, and its pathological type is mostly poorly differentiated squamous cell carcinoma. Since the nasopharynx is located deep in the head and neck, early diagnosis and timely treatment are critical to patient survival. However, nasopharyngeal carcinoma tumors are small in size and vary widely in shape, and it is also a challenge for experienced doctors to delineate tumor contours. In addition, due to the special location of nasopharyngeal carcinoma, complex treatments such as radiotherapy or surgical resection are often required, so accurate pathological diagnosis is also very important for the selection of treatment options. However, the current deep learning segmentation model faces the problems of inaccurate segmentation and unstable segmentation process, which are mainly limited by the accuracy of data sets, fuzzy boundaries, and complex lines. In order to solve these two challenges, this article proposes a hybrid model WET-UNet based on the UNet network as a powerful alternative for nasopharyngeal cancer image segmentation. On the one hand, wavelet transform is integrated into UNet to enhance the lesion boundary information by using low-frequency components to adjust the encoder at low frequencies and optimize the subsequent computational process of the Transformer to improve the accuracy and robustness of image segmentation. On the other hand, the attention mechanism retains the most valuable pixels in the image for us, captures the remote dependencies, and enables the network to learn more representative features to improve the recognition ability of the model. Comparative experiments show that our network structure outperforms other models for nasopharyngeal cancer image segmentation, and we demonstrate the effectiveness of adding two modules to help tumor segmentation. The total data set of this article is 5000, and the ratio of training and verification is 8:2. In the experiment, accuracy = 85.2% and precision = 84.9% can show that our proposed model has good performance in nasopharyngeal cancer image segmentation.

SQSTM1 downregulates avian metapneumovirus subgroup C replication via mediating selective autophagic degradation of viral M2-2 protein.

Avian metapneumovirus subgroup C (aMPV/C), an important pathogen causing acute respiratory infection in chickens and turkeys, contributes to substantial economic losses in the poultry industry worldwide. aMPV/C has been reported to induce autophagy, which is beneficial to virus replication. Sequestosome 1 (SQSTM1/P62), a selective autophagic receptor, plays a crucial role in viral replication by clearing ubiquitinated proteins. However, the relationship between SQSTM1-mediated selective autophagy and aMPV/C replication is unclear. In this study, we found that the expression of SQSTM1 negatively regulates aMPV/C replication by reducing viral protein expression and viral titers. Further studies revealed that the interaction between SQSTM1 and aMPV/C M2-2 protein is mediated via the Phox and Bem1 (PB1) domain of the former, which recognizes a ubiquitinated lysine at position 67 of the M2-2 protein, and finally degrades M2-2 via SQSTM1-mediated selective autophagy. Collectively, our results reveal that SQSTM1 degrades M2-2 via a process of selective autophagy to suppress aMPV/C replication, thereby providing novel insights for the prevention and control of aMPV/C infection.IMPORTANCEThe selective autophagy plays an important role in virus replication. As an emerging pathogen of avian respiratory virus, clarification of the effect of SQSTM1, a selective autophagic receptor, on aMPV/C replication in host cells enables us to better understand the viral pathogenesis. Previous study showed that aMPV/C infection reduced the SQSTM1 expression accompanied by virus proliferation, but the specific regulatory mechanism between them was still unclear. In this study, we demonstrated for the first time that SQSTM1 recognizes the 67th amino acid of M2-2 protein by the interaction between them, followed by M2-2 degradation via the SQSTM1-mediated selective autophagy, and finally inhibits aMPV/C replication. This information supplies the mechanism by which SQSTM1 negatively regulates viral replication, and provides new insights for preventing and controlling aMPV/C infection.

[SWI/SNF Complex Gene Mutations Promote the Liver Metastasis 
of Non-small Cell Lung Cancer Cells in NSI Mice].

BACKGROUND: The switch/sucrose nonfermentable chromatin-remodeling (SWI/SNF) complex is a pivotal chromatin remodeling complex, and the genomic alterations (GAs) of the SWI/SNF complex are observed in several cancer types, correlating with multiple biological features of tumor cells. However, their role in liver metastasis of non-small cell lung cancer (NSCLC) remains unclear. Our study aims to investigate the role and potential mechanisms underlying NSCLC liver metastasis induced by the GAs of SWI/SNF complex. METHODS: The GAs of SWI/SNF complex in NSCLC cell lines (H1299, H23 and H460) were identified by whole-exome sequencing (WES). ARID1A knockout H1299 cell was constructed with the CRISPR/Cas9 technology. The mouse model of liver metastasis from NSCLC was established to simulate lung cancer liver metastasis and observe the metastasis rate under different gene mutation conditions. RNA sequencing and Western blot were conducted for differential gene expression analysis. Immunohistochemistry (IHC) analysis was used to assess protein expression levels of SWI/SNF-regulated target molecules in mouse liver metastases. RESULTS: WES analysis revealed intracellular gene mutations. The animal experiments demonstrated a correlation between the GAs of SWI/SNF complex and a higher liver metastasis rate in immunodeficient mice. Transcriptome sequencing and Western blot analysis showed upregulated expression of ALDH1A1 and APOBEC3B in SWI/SNF-mut cells, particularly in ARID1A-deficient H460 and H1299 sgARID1A cells. IHC staining of mouse liver metastases further demonstrated elevated expression of ALDH1A1 in the H460 and H1299 sgARID1A group. CONCLUSIONS: This study underscores the critical role of the GAs of SWI/SNF complex, such as ARID1A and SMARCA4, in promoting liver metastasis of lung cancer cells. The GAs of SWI/SNF complex may promote liver-specific metastasis by upregulating ALDH1A1 and APOBEC3B expression, providing novel insights into the molecular mechanisms underlying lung cancer liver metastasis.

Progress of Ultrasound Techniques in the Evaluation of Carotid Vulnerable Plaque Neovascularization.

BACKGROUND: The rupture and detachment of unstable plaques in the carotid artery can cause embolism in the cerebral artery, leading to acute cerebrovascular events. Intraplaque neovascularization (IPN) is a very important contributor to carotid plaque instability, and its evolution plays a key role in determining the outcome of vulnerable plaques. Ultrasound techniques, represented by contrast-enhanced ultrasound and superb microvascular imaging, are reported to be non-invasive, rapid and effective techniques for the semi-quantitative or quantitative evaluation for IPN. Although ultrasound techniques have been widely applied in the detection of carotid plaque stability, it has been limited owing to the lack of unified IPN quantitative standards. SUMMARY: This review summarizes the application and semi-quantitative/quantitative diagnostic standards of ultrasound techniques in evaluating IPN, and looks forward to the prospects of the future research. With the development of novel techniques like artificial intelligence, ultrasound will offer appropriate selections for achieving more accuracy diagnosis. KEY MESSAGES: A large number of studies have used contrast-enhanced ultrasound and superb microvascular imaging to detect IPN and perform semi-quantitative grading to predict the occurrence of diseases such as stroke, and to accurately assess drug efficacy based on rating changes. These studies have made great progress at this stage, but more accurate and intelligent quantitative imaging methods should become the future development goal.

DCTR U-Net: automatic segmentation algorithm for medical images of nasopharyngeal cancer in the context of deep learning.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that occurs in the wall of the nasopharyngeal cavity and is prevalent in Southern China, Southeast Asia, North Africa, and the Middle East. According to studies, NPC is one of the most common malignant tumors in Hainan, China, and it has the highest incidence rate among otorhinolaryngological malignancies. We proposed a new deep learning network model to improve the segmentation accuracy of the target region of nasopharyngeal cancer. Our model is based on the U-Net-based network, to which we add Dilated Convolution Module, Transformer Module, and Residual Module. The new deep learning network model can effectively solve the problem of restricted convolutional fields of perception and achieve global and local multi-scale feature fusion. In our experiments, the proposed network was trained and validated using 10-fold cross-validation based on the records of 300 clinical patients. The results of our network were evaluated using the dice similarity coefficient (DSC) and the average symmetric surface distance (ASSD). The DSC and ASSD values are 0.852 and 0.544 mm, respectively. With the effective combination of the Dilated Convolution Module, Transformer Module, and Residual Module, we significantly improved the segmentation performance of the target region of the NPC.

Establishment of ultrasound-responsive SonoBacteriaBot for targeted drug delivery and controlled release.

Bacteria-driven biohybrid microbots have shown great potential in cancer treatment. However, how precisely controlling drug release at the tumor site is still an issue. To overcome the limitation of this system, we proposed the ultrasound-responsive SonoBacteriaBot (DOX-PFP-PLGA@EcM). Doxorubicin (DOX) and perfluoro-n-pentane (PFP) were encapsulated in polylactic acid-glycolic acid (PLGA) to form ultrasound-responsive DOX-PFP-PLGA nanodroplets. Then, DOX-PFP-PLGA@EcM is created by DOX-PFP-PLGA amide-bonded to the surface of E. coli MG1655 (EcM). The DOX-PFP-PLGA@EcM was proved to have the characteristics of high tumor-targeting efficiency, controlled drug release capability, and ultrasound imaging. Based on the acoustic phase change function of nanodroplets, DOX-PFP-PLGA@EcM enhance the signal of US imaging after ultrasound irradiation. Meanwhile, the DOX loaded into DOX-PFP-PLGA@EcM can be released. After being intravenously injected, DOX-PFP-PLGA@EcM can efficiently accumulate in tumors without causing harm to critical organs. In conclusion, the SonoBacteriaBot has significant benefits in real-time monitoring and controlled drug release, which has significant potential applications for therapeutic drug delivery in clinical settings.

The cGAS/STING signaling pathway: a cross-talk of infection, senescence and tumors.

The cGAS/STING signaling pathway is an important part of the cytoplasmic DNA sensor, which can trigger a type I interferon response to microbial infection when pathogenic DNA is detected. However, continuous inhibition of cGAS/STING signaling by viral infection may be an important cause of tumorigenesis. At the same time, recent studies have shown that although the cGAS/STING signaling pathway also plays a core role in anti-tumor immunity and cell senescence, the inflammatory response induced by cGAS/STING signaling will also promote tumorigenesis in different backgrounds. Here, we discuss the role of cGAS/STING in the context of infection, senescence, and tumors, especially with respect to progression, to facilitate a better understanding of the mechanism of the cGAS/STING pathway.

The Network of Interactions between the Porcine Epidemic Diarrhea Virus Nucleocapsid and Host Cellular Proteins.

Host-virus protein interactions are critical for intracellular viral propagation. Understanding the interactions between cellular and viral proteins may help us develop new antiviral strategies. Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that causes severe damage to the global swine industry. Here, we employed co-immunoprecipitation and liquid chromatography-mass spectrometry to characterize 426 unique PEDV nucleocapsid (N) protein-binding proteins in infected Vero cells. A protein-protein interaction network (PPI) was created, and gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) database analyses revealed that the PEDV N-bound proteins belong to different cellular pathways, such as nucleic acid binding, ribonucleoprotein complex binding, RNA methyltransferase, and polymerase activities. Interactions of the PEDV N protein with 11 putative proteins: tripartite motif containing 21, DEAD-box RNA helicase 24, G3BP stress granule assembly factor 1, heat shock protein family A member 8, heat shock protein 90 alpha family class B member 1, YTH domain containing 1, nucleolin, Y-box binding protein 1, vimentin, heterogeneous nuclear ribonucleoprotein A2/B1, and karyopherin subunit alpha 1, were further confirmed by in vitro co-immunoprecipitation assay. In summary, studying an interaction network can facilitate the identification of antiviral therapeutic strategies and novel targets for PEDV infection.

The Evolution, Genomic Epidemiology, and Transmission Dynamics of Tembusu Virus.

Tembusu virus (TMUV) can induce severe egg drop syndrome in ducks, causing significant economic losses. In this study, the possible origin, genomic epidemiology, and transmission dynamics of TMUV were determined. The time to the most recent common ancestor of TMUV was found to be 1924, earlier than that previously reported. The effective population size of TMUV increased rapidly from 2010 to 2013 and was associated with the diversification of different TMUV clusters. TMUV was classified into three clusters (clusters 1, 2, and 3) based on the envelope (E) protein. Subcluster 2.2, within cluster 2, is the most prevalent, and the occurrence of these mutations is accompanied by changes in the virulence and infectivity of the virus. Two positive selections on codons located in the NS3 and NS5 genes (591 of NS3 and 883 of NS5) were identified, which might have caused changes in the ability of the virus to replicate. Based on phylogeographic analysis, Malaysia was the most likely country of origin for TMUV, while Shandong Province was the earliest province of origin in China. This study has important implications for understanding TMUV and provides suggestions for its prevention and control.

Molecular mechanisms for ABCA1-mediated cholesterol efflux.

The maintenance of cellular cholesterol homeostasis is essential for normal cell function and viability. Excessive cholesterol accumulation is detrimental to cells and serves as the molecular basis of many diseases, such as atherosclerosis, Alzheimer's disease, and diabetes mellitus. The peripheral cells do not have the ability to degrade cholesterol. Cholesterol efflux is therefore the only pathway to eliminate excessive cholesterol from these cells. This process is predominantly mediated by ATP-binding cassette transporter A1 (ABCA1), an integral membrane protein. ABCA1 is known to transfer intracellular free cholesterol and phospholipids to apolipoprotein A-I (apoA-I) for generating nascent high-density lipoprotein (nHDL) particles. nHDL can accept more free cholesterol from peripheral cells. Free cholesterol is then converted to cholesteryl ester by lecithin:cholesterol acyltransferase to form mature HDL. HDL-bound cholesterol enters the liver for biliary secretion and fecal excretion. Although how cholesterol is transported by ABCA1 to apoA-I remains incompletely understood, nine models have been proposed to explain this effect. In this review, we focus on the current view of the mechanisms underlying ABCA1-mediated cholesterol efflux to provide an important framework for future investigation and lipid-lowering therapy.

Anti-tumor effect of ginkgetin on human hepatocellular carcinoma cell lines by inducing cell cycle arrest and promoting cell apoptosis.

This study explored the anti-tumor effect of ginkgetin, an extract from ginkgo biloba, on human hepatocellular carcinoma cell lines and the underlying mechanisms. Cell viability was measured by MTT assay. Apoptotic cell morphology was observed under an inverted microscope after Hoechst 33,258 staining, and the ratio of apoptotic and necrotic cells was examined by flow cytometry after FITC/PI staining. Cell cycle changes were analyzed using flow cytometry. Cytochrome c release and caspase 3 and 8 activities were monitored using the relevant reagent kits. The levels of cell cycle-related proteins were detected by Western blot. MTT results indicated that ginkgetin significantly reduced HepG2 cell viability in a dose-dependent manner. Cellular morphology observation revealed that ginkgetin induced typical apoptotic morphological features of HepG2 cells, such as increased apoptotic bodies and cell shrinkage. Cell cycle analysis showed that ginkgetin increased the proportion of cells in the S phase. S-phase cell accumulation could be attributed to the decreased expression of cell cycle regulatory factors. Similarly, ginkgetin also induced the apoptosis and S phase cell accumulation of another human HCC cell line SK-HEP-1. Furthermore, ginkgetin treatment increased caspase-3 activity and cytochrome c release but not caspase-8 activity, implying that ginkgetin might mediate cell apoptosis through the mitochondrial pathway. In addition, the tumor formation experiment in nude mice showed that ginkgetin administration inhibited tumor growth. These results suggest that ginkgetin could be a cell apoptosis stimulator by affecting the balance between cell proliferation and apoptosis, suggesting that ginkgetin might be suitable for human HCC treatment.