Effect of Drebrin protein on the proliferation of PEDV in Vero cells

Previous studies have revealed that developmental regulated brain protein (Drebrin) is involved in cell- to-cell communication, nerve transmission, tumor metastasis, spermatogenesis and other life activities, but there are few studies on viruses. The aim of the current research was therefore, to study the function of Drebrin and its effect on the proliferation of porcine epidemic diarrhea virus (PEDV). The Drebrin gene was cloned according to the Drebrin gene sequence (XM_008015438.2) of Chlorocebus sabaeus registered by GenBank, and the phylogenetic tree was constructed to analyze its homology. The results showed that the CDS region of Vero cells Drebrin gene was 2088 bp long, encoding 695 amino acids, and was relatively conserved and had high homology with all species. To investigate the effect of Drebrin on the proliferation of PEDV in Vero cells, the eukaryotic expression vector pcDNA3.1-Drebrin-Flag was constructed. After transfection of Vero cells with different concentrations of pcDNA3.1-Drebrin-Flag, cells were infected with PEDV. Our results showed that overexpression of Drebrin in Vero cells could significantly inhibit the intracellular PEDV mRNA level and N protein expression, reduce the extracellular virus titer and inhibit the proliferation of PEDV. Further study on the interaction between Drebrin and PEDV S proteins by laser confocal technique was also performed. The results showed that Drebrin and S protein were co-located in the cytoplasm, suggesting that the two proteins may interact with each other. This study demonstrated for the first time that Drebrin can inhibit PEDV proliferation in Vero cells, laying a foundation for further research in to Drebrin function and provides a valuable information for anti-PEDV research.

Fructus aurantii extracts ameliorate intestinal inflammation and regulate the intestinal barrier through Fc epsilon RI signaling pathway

Fructus Aurantii (FA) is the dry and immature fruit of Citrus aurantium L. and its rutaceous cultivars. FA has been widely used to treat digestive system diseases since ancient China, and it promotes gastrointestinal (GI) motility in functional dyspepsia (FD), but its potential therapeutic mechanisms remain unclear. We examined the effects of FA ethanol extracts in an iodoacetamide (IA)-induced FD rat model. Firstly, key FA therapy targets for FD were gathered using systematic pharmacology. Combined with systemic pharmacological analyses, plasma metabolomics based on UPLC-QTOF-MS were conducted. Then, MetaboAnalyst was used to jointly analyze systemic pharmacology targets and metabolomic metabolites to select key metabolic pathways. Finally, the key path is verified by experiments. FA exerted distinct therapeutic effects in anti-inflammation and promoting gastrointestinal motility in our IA-induced FD rat model. When compared with the model group, FA down-regulated the inflammatory factors interleukin 1beta and tumor necrosis factor-a. At the same time, FA up-regulated tight junction proteins in the intestinal epithelial barrier. Through the integrated analysis of metabolomics and systemic pharmacology, we conducted experimental verification on Fc epsilon RI signaling pathway. When compared with the model group, FA down-regulatedphospho-mitogen activated protein kinase, phospho-extracellular signal regulated kinase1/2, myosin light chain kinase, and phospho-myosin regulatory light chain protein levels. Thus, FA ameliorated FD by regulating the Fc epsilon RI signaling pathway. Our integrated strategy identified underlying FA mechanisms toward FD treatment and provided a foundation for FA development as a clinical agent for FD.

Discovery of alliin as a putative inhibitor of the main protease of SARS-CoV-2 by molecular docking.

The outbreak of viral pneumonia caused by the novel coronavirus SARS-CoV-2 that began in December 2019 caused high mortality. It has been suggested that the main protease (Mpro) of SARS-CoV-2 may be an important target to discover pharmaceutical compounds for the therapy of this life-threatening disease. Remdesivir, ritonavir and chloroquine have all been reported to play a role in suppressing SARS-CoV-2. Here, we applied a molecular docking method to study the binding stability of these drugs with SARS-CoV-2 Mpro. It appeared that the ligand-protein binding stability of the alliin and SARS-CoV-2 Mpro complex was better than others. The results suggested that alliin may serve as a good candidate as an inhibitor of SARS-CoV-2 Mpro. Therefore, the present research may provide some meaningful guidance for the prevention and treatment of SARS-CoV-2.