Goose astrovirus genotype 2 induces autophagy in goose renal tubular epithelial cells requiring the ERK2 signaling pathway: pharmacological evidence for a pro-viral role of autophagy

Goose astrovirus genotype 2 (GAstV-2) is an emerging pathogen responsible for gout in goslings, posing a serious threat to the goose breeding industry in China. Although the disease has caused significant economic losses, the mechanisms underlying GAstV-2-induced pathogenesis, particularly gout formation, remain poorly understood. In this study, we investigated the effect of GAstV-2 infection on autophagy in primary goose renal tubular epithelial (GRTE) cells and explored the associated signaling pathways. Our results demonstrated that GAstV-2 infection induced autophagic flux in GRTE cells, and pharmacological induction of autophagy increased, whereas inhibition decreased, GAstV-2 replication, which is consistent with a pro-viral role of autophagy. Furthermore, we found that GAstV-2 induced autophagy in GRTE cells through the extracellular signal-regulated kinase 2 (ERK2) signaling pathway, as determined using specific inhibitors and RNA interference assays. Collectively, this study reveals that GAstV-2 induces autophagy in GRTE cells requiring the ERK2 signaling pathway, and pharmacological induction of autophagy increased, whereas inhibition decreased, viral replication, consistent with a pro-viral function of autophagy.