miR‐124 mediates the expression of ccBax to regulate Cyprinid herpesvirus 2 (CyHV‐2)‐induced apoptosis and viral replication

Abstract

AbstractCyprinid herpesvirus 2 (CyHV‐2), the etiological agent of herpesvirus haematopoietic necrosis (HVHN) in carp and goldfish, has caused significant economic losses in the aquaculture industry. During viral infection, the host initiates a series of active or passive defences to regulate the process of virus infection. Apoptosis is a key component of active cellular defence, and members of the Bcl‐2 family have been shown to play a critical role in the apoptotic process. However, the mechanism of action of the Bcl‐2 family in inducing apoptosis during CyHV‐2 infection remains unclear. In this study, we revealed the molecular mechanism of miRNA‐mediated silver crucian carp BAX (ccBax) in CyHV‐2‐induced apoptosis for the first time and demonstrated that the overexpression of miR‐124 suppressed ccBax expression and significantly down‐regulated apoptosis in caudal fin cells of Carassius auratus gibelio (GiCF), while miR‐124 inhibitors were the opposite. These studies indicated that miR‐124 inhibits CyHV‐2‐induced apoptosis by reducing the expression of ccBax. Furthermore, the fact that transfection of miR‐124 mimics promoted CyHV‐2 replication, whereas miR‐124 inhibitors inhibited CyHV‐2 replication, indicated that miR‐124 inhibited CyHV‐2‐induced apoptosis and contributed to viral replication. All these results suggested that miR‐124 suppresses virus‐induced apoptosis and promotes viral replication by targeting and regulating ccBax expression.