Conclusion
These results demonstrated that CS-SeNPs suppress PRRSV-induced apoptosis in Marc-145 cells via the ROS/JNK signaling pathway, thereby inhibiting PRRSV replication, which suggested the potential antiviral activity of CS-SeNPs that deserves further investigation for clinical applications.
Methods
In this study, CS-SeNPs were synthesized by chemical reduction and characterized by assessing the morphology, size distribution, zeta potential, and element composition. Marc-145 cells were infected with r-PRRSV-EGFP (0.1 MOI) and inoculated with CS-SeNPs (10 μM). Subsequently, the concentrations of hydrogen peroxide (H2O2) and glutathione (GSH), and glutathione peroxidase (GSH-Px) activity were measured using specific commercial assay kits. ORF5 RNA expression, viral titer, and nucleocapsid (N) protein expression were assessed using qRT-PCR, TCID50, and Western blot. ROS generation, apoptosis rates, and JNK /caspase-3/PARP protein expression were evaluated using dihydroethidium staining, flow cytometry, and Western blot.
Results
The results showed that CS-SeNPs treatment significantly suppressed oxidative stress induced by r-PRRSV-EGFP infection by increasing GSH-Px activity, promoting GSH production, and inhibiting H2O2 synthesis. CS-SeNPs treatment significantly inhibited ORF5 gene expression, viral titers, and N protein of r-PRRSV-EGFP at 24 and 48 hours post-infection (hpi) in Marc-145 cells. The increase in apoptosis rates induced by r-PRRSV-EGFP infection was significantly decreased by CS-SeNPs inoculation through inhibiting ROS generation, JNK phosphorylation levels, and cleavage of caspase-3 and PARP mainly at 48 hpi.