Glutamine Deficiency Promotes PCV2 Infection through Induction of Autophagy via Activation of ROS-Mediated JAK2/STAT3 Signaling Pathway

Abstract

Porcine circovirus type 2 (PCV2) is an important pathogen in swine herds. We previously reported that glutamine (Gln) deficiency promoted PCV2 infection in vitro. Here, we established a Gln deficiency model in vivo and further investigated the detailed molecular mechanisms. In vivo and in vitro, Gln deficiency promoted PCV2 infection, which was evident through increased viral yields and PCV2 Cap protein synthesis. It also induced autophagy, as demonstrated by the increases in LC3-II conversion, SQSTM1 degradation, and GFP-LC3 dot accumulation. Autophagy inhibition abolished the effects of Gln deficiency on PCV2 infection. Inhibition of ROS generation alleviated the Gln deficiency-activated JAK2/STAT3 signaling pathway, thereby inhibiting autophagy induction. In vitro, the inhibition of STAT3 by an inhibitor or RNA interference blocked autophagy, thus reversing the effects of Gln deficiency on PCV2 infection. These results indicate that Gln deficiency activates autophagy by upregulating ROS-medicated JAK2/STAT3 signaling and thereby promoting PCV2 infection.

Low-level contamination of deoxynivalenol: A threat from environmental toxins to porcine epidemic diarrhea virus infection

“…Cell viability was monitored by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT; Sigma, USA) assay as previously described ( Liu et al 2018a ). Briefly, IPEC-J2 cells were cultured in 96-well plates at a density of 5 × 10 3 cells/well with corresponding treatments.…”

“…Viral titers were determined by 50% endpoint dilution (50% tissue culture infective dose [TCID50]) assays on IPEC-J2 cells as previously described ( Liu et al 2018a ). Briefly, IPEC-J2 cells cultured in 96-well plates were inoculated with 10-fold dilutions of the harvested culture supernatants for indicated time.…”

2,3,4′,5-Tetrahydroxystilbene-2-O-β-D-Glucoside (THSG) Activates the Nrf2 Antioxidant Pathway and Attenuates Oxidative Stress-Induced Cell Death in Mouse Cochlear UB/OC-2 Cells

“…Excess ROS upregulate autophagy to remove proteins and organelles with oxidative damage in the cytoplasm [18][19][20][21]. LC3-phosphatidylethanolamine conjugate (LC3-II), a marker for autophagy, is involved in the formation of autophagosome membranes, and autophagosomes might fuse with lysosomes to degrade damaged cytosolic components [22][23][24][25].…”

Deoxynivalenol Promotes Porcine Epidemic Diarrhea Virus Infection and Aggravates Gut Barrier Injury

“…Cell viability was monitored by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT; Sigma, USA) assay as previously described [52]. Briefly, IPEC-J2 cells were cultured in 96-well plates at a density of 5 × 10 3 cells/well with corresponding treatments.…”

“…Viral titers were determined by 50% endpoint dilution (50% tissue culture infective dose [TCID50]) assays on IPEC-J2 cells as previously described [52]. Briefly, IPEC-J2 cells cultured in 96-well plates were inoculated with 10-fold dilutions of the harvested culture supernatants for indicated time.…”