Selenomethionine mitigates effects of porcine deltacoronavirus - induced oxidative stress and apoptosis via NRF2-HO-1 signaling pathway

Porcine deltacoronavirus (PDCoV) is a newly discovered porcine enteric coronavirus that mainly causes severe clinical diarrhea and intestinal pathological damage in piglets, and also has the potential for cross-species transmission in recent years. Selenium is an essential trace element for organisms and has been demonstrated to have antiviral effects. In this study, the protective effect of selenomethionine (Se-Met) on PDCoV-infection was evaluated in vivo and in vitro, and the molecular mechanism by which Se-Met alleviates PDCoV-induced inflammatory injury and oxidative damage were investigated. Results indicated that Se-Met could improve the pig’s growth performance, exert antiviral effects by regulating the intestinal physical, chemical, microbial and immune barriers to alleviate piglet diarrhea caused by PDCoV infection. In vivo and in vitro experiments verified the stronger protective effect of Se-Met against oxidative stress induced by PDCoV infection, reducing cell apoptosis and an improving cellular redox state. Moreover, Se-Met protects the intestinal barrier from oxidative stress-induced damage caused by PDCoV infection by activating nuclear factor (erythroid-derived-2)-like 2 (NRF2) - heme oxygenase (HO)-1 signaling pathway and cell apoptosis. Overall, our results suggest that Se-Met is a promising selenium species with potential application in treating oxidative stress related intestinal diseases caused by viral infections, which provides a theoretical basis for the development of nutritional antiviral feed additives.