Potential mechanism underlying the effect of matrine on COVID-19 patients revealed through network pharmacological approaches and molecular docking analysis.

BACKGROUND: The clinical efficacy of matrine in treating coronavirus disease (COVID-19) has been confirmed; however, its underlying mechanism of action remains unknown. METHODS: TCMSP, SwissTargetPrediction, SEA, GeneCards, CTD, and TTD were used to identify potential targets for matrine in SARS-CoV-2. Cytoscape software was used to determine the target-pathway network for topographical analysis. The online STRING analysis platform and Cytoscape were together used to generate a PPI network and for GO and KEGG pathway enrichment analysis. Finally, molecular docking simulations were performed to study matrine-Mpro, matrine-ACE2, and matrine-RdRp interactions. RESULTS: Ten common matrine targets were obtained, particularly including TNF-α, IL-6, and CASP3. GO and KEGG pathway enrichment analysis revealed five significantly enriched signalling pathways involved in cell proliferation, apoptosis, programmed cell death, and immune responses. CONCLUSIONS: During COVID-19 treatment, matrine regulates viral replication, host cell apoptosis, and inflammation by targeting the TNF-α, IL-6, and CASP3 in the TNF signalling pathway.

Precise Detection on Cell-Cell Fusion by a Facile Molecular Beacon-Based Method.

Cell-cell fusion studies provide an experimental platform for evaluating disease progression and investigating cell infection. However, to realize sensitive and quantitative detection on cell-cell fusion is still a challenge. Herein, we report a facile molecular beacon (MB)-based method for precise detection on cell-cell fusion. By transfection of the spike protein (S protein) and enhanced green fluorescent protein (EGFP) in HEK 293 cells, the virus-mimicking fusogenic effector cells 293-S-EGFP cells were constructed to interact with target cells. Before mixing the effector cells with the target cells, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression in 293-S-EGFP cells was silenced, and the MB for GAPDH mRNA detection was delivered into the GAPDH silenced 293-S-EGFP cells. Once cell-cell fusion occurred, MB migrated from the GAPDH silenced effector cells to the target cells and hybridized with GAPDH mRNA in the target cells to induce fluorescence emission. The cell-cell fusion can be easily visualized and quantitated by fluorescence microscopy and flow cytometry. The fluorescence intensity is strongly dependent on the number of fused target cells. This MB-based method can easily identify the differences in the cell fusions for various target cells with different angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) expression levels, resulting in dramatically different fluorescence intensities in fused target cells. Our study provides a convenient and efficient quantitative detection approach to study cell-cell fusion.

Synergistic Immunity and Protection in Mice by Co-Immunization with DNA Vaccines Encoding the Spike Protein and Other Structural Proteins of SARS-CoV-2.

The emergence of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated recurring worldwide infection outbreaks. These highly mutated variants reduce the effectiveness of current coronavirus disease 2019 (COVID-19) vaccines, which are designed to target only the spike (S) protein of the original virus. Except for the S of SARS-CoV-2, the immunoprotective potential of other structural proteins (nucleocapsid, N; envelope, E; membrane, M) as vaccine target antigens is still unclear and worthy of investigation. In this study, synthetic DNA vaccines encoding four SARS-CoV-2 structural proteins (pS, pN, pE, and pM) were developed, and mice were immunized with three doses via intramuscular injection and electroporation. Notably, co-immunization with two DNA vaccines that expressed the S and N proteins induced higher neutralizing antibodies and was more effective in reducing the SARS-CoV-2 viral load than the S protein alone in mice. In addition, pS co-immunization with either pN or pE + pM induced a higher S protein-specific cellular immunity after three immunizations and caused milder histopathological changes than pS alone post-challenge. The role of the conserved structural proteins of SARS-CoV-2, including the N/E/M proteins, should be investigated further for their applications in vaccine design, such as mRNA vaccines.

DNA Vaccines Expressing the Envelope and Membrane Proteins Provide Partial Protection Against SARS-CoV-2 in Mice.

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a public health emergency of international concern, and an effective vaccine is urgently needed to control the pandemic. Envelope (E) and membrane (M) proteins are highly conserved structural proteins among SARS-CoV-2 and SARS-CoV and have been proposed as potential targets for the development of cross-protective vaccines. Here, synthetic DNA vaccines encoding SARS-CoV-2 E/M proteins (called p-SARS-CoV-2-E/M) were developed, and mice were immunised with three doses via intramuscular injection and electroporation. Significant cellular immune responses were elicited, whereas no robust humoral immunity was detected. In addition, novel H-2d-restricted T-cell epitopes were identified. Notably, although no drop in lung tissue virus titre was detected in DNA-vaccinated mice post-challenge with SARS-CoV-2, immunisation with either p-SARS-CoV-2-E or p-SARS-CoV-2-M provided minor protection and co-immunisation with p-SARS-CoV-2-E+M increased protection. Therefore, E/M proteins should be considered as vaccine candidates as they may be valuable in the optimisation of vaccination strategies against COVID-19.

Differential neutralization and inhibition of SARS-CoV-2 variants by antibodies elicited by COVID-19 mRNA vaccines (preprint)

The divergence of SARS-CoV-2 into variants of concern/interest (VOC/VOI) necessitated analysis of their impact on vaccines. Escape from vaccine-induced antibodies by SARS-CoV-2 VOC/VOIs was analyzed to ascertain and rank their risk. The variants showed differential reductions in neutralization and replication titers by the post-vaccination sera with Beta variant showing the most neutralization escape that was mechanistically driven by mutations in both the N-terminal domain and receptor-binding domain of the spike.

Body mass index changes among children and adolescents in Suzhou before and after COVID-19 outbreak

Objective: To explore body mass index (BMI) changes among children and adolescents in Suzhou before and after COVID-19 outbreak, and to provide a reference for improving physical health of children and adolescents.

Material Basis and Mechanism of Chansu Injection for COVID-19 Treatment Based on Network Pharmacology and Molecular Docking Technology.

PURPOSE: The clinical efficacy of Chansu injection for COVID-19 treatment has been confirmed. Its mechanism of action remains unclear. We used network pharmacology and molecular docking technology to explore the potential material basis and mechanism of action of Chansu injection for COVID-19. METHODS: The main components of Chansu injection were determined using HPLC. The PharmMapper, SwissTargetPrediction, SEA, and TCMID databases were used to screen for the active ingredients and therapeutic targets of Chansu injection, while the OMIM and GeneCards Suite databases were used to search for COVID-19-related targets. The STRING database was used for protein-protein interaction (PPI) network construction and topological analysis, while DAVID was used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the core targets. The main active compounds of Chansu injection were docked with 3CL protease, ACE2, RdRp, and spike protein. RESULTS: The three Chansu injection compounds were identified using HPLC. A total of 236 drug-related targets and 16,611 disease-related targets were identified, and 77 common targets were determined through mapping. The PPI mapping results revealed that 16 core targets were obtained through topological analysis and screening. Furthermore, GO and KEGG pathway enrichment analyses revealed that the PI3K and JAK-STAT signaling pathways are the major pathways. The molecular docking results suggest that the three Chansu injection components have high binding energies to the S protein. CONCLUSIONS: The potential mechanism of Chansu injection for COVID-19 involves multiple targets and pathways, thereby providing a scientific basis for its clinical application and further research.

To explore the material basis and mechanism of Lianhua Qingwen Prescription against COVID-19 based on network pharmacology

Objective: In the treatment of COVID-19, the application of Lianhua Qingwen Prescription has become growingly widespread, however, the mechanism of action is still unclear. To explore the material basis and mechanism of Lianhua Qingwen Prescription against SARS-CoV-2, to provide a reference for the treatment of COVID-19. Methods: Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), SwissTargetPrediction, and Similarity Ensemble Approach (SEA) database were used to search the chemical constituents and targets of Lianhua Qingwen Prescription. The targets of COVID-19 were screened by GeneCards, Therapeutic Target Database (TTD), and Comparative Toxicogenomics Database (CTD). Cytoscape software was used to construct a “drug-component-target” network diagram and the mechanism of action was predicted by enrichment analysis. Results: Two hundred and twenty four active components, 246 drug therapeutic targets, and 16,611 potential targets of Lianhua Qingwen Prescription were mined out. Moreover, 163 common targets were obtained, including PTGS2, IL6, CASP3, mapk1, EGFR, ACE2, etc. Thirty seven items were obtained by Gene Ontology (GO) enrichment analysis, mainly involving T-cell activation, virus receptor, and inflammatory reaction, etc. One hundred and forty items were obtained by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enriched analysis, including TNF signaling pathway, MAPK signaling pathway, and IL-17 signaling pathway. Conclusion: Compounds such as quercetin and kaempferol play an important role in anti-COVID-19 through the TNF signaling pathway and MAPK signaling pathway.

Advances in treatment of COVID-19

The novel coronavirus pneumonia is an acute infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The global pandemic of this novel coronavirus pneumonia has greatly threatened human health and brought enormous economy losses. By the end of May 20, 2020, the pandemic of this disease had caused more than 2.70 million infections and more than 320 thousand deaths. This paper reviewed the recent advances in the treatment of the novel coronavirus pneumonia to provide basic references for disease control.