Role of Autophagy in Goose Astrovirus-Induced Renal Injury in Goslings

Goose astrovirus (GoAstV) is a newly identified virus affecting geese, leading to goose gout, which is marked by urate deposits in organs and joints. This research investigates the role of autophagy in renal damage caused by GoAstV in goslings. The findings indicated that GoAstV infection in goslings resulted in characteristic clinical manifestations, with renal tissues displaying tubular swelling, inflammatory infiltration, and autophagosome formation. In vivo experiments demonstrated a significant upregulation of mRNA levels for autophagy-related factors, including AMPK, LC3A, ATG5, ATG7, P62, Beclin1, AMBRA1 and GABARAPL1, while mTOR and LC3B levels were notably decreased. At 3 dpi, the protein expression levels of ATG5, Beclin1, and LC3B II/I increased, while P62 levels decreased, suggesting autophagy activation. In vitro analyses revealed that GoAstV infection led to enhanced autophagy; however, the concurrent upregulation of LC3B II/I and P62 proteins suggested an obstruction in the autophagic flux. Upon the inhibition of autophagy with 3-methyladenine (3-MA, autophagy inhibitor), there was a significant reduction in the expression of autophagy-related factors, accompanied by a marked decrease in viral replication rates. In conclusion, GoAstV infection in gosling kidney cells initially triggers enhanced autophagy and subsequently causes a blockage in the autophagic flux. The virus exploits autophagosomes for replication, ultimately resulting in kidney damage. The application of 3-MA effectively inhibits this autophagic process and diminishes viral replication.