Functional involvement of AMPK in Lumpy skin disease virus replication and associated cellular stress responses

Lumpy skin disease virus (LSDV) infection induces extensive cellular stress responses and metabolic reprogramming in host cells. However, the regulatory mechanisms linking these changes to viral replication remain unclear. In this study, MAC-T cells were used as an in vitro infection model to investigate LSDV-induced cellular stress responses and their impact on viral replication. Transcriptomic analysis revealed that LSDV infection activated pathways associated with energy stress, oxidative stress, and endoplasmic reticulum (ER) stress, suggesting disruption of cellular energy homeostasis and redox balance. Transmission electron microscopy further demonstrated mitochondrial structural damage in infected cells. Subsequent analyses showed that the ATP/AMP ratio and lactate metabolism decreased during infection, accompanied by elevated mitochondrial calcium levels and excessive reactive oxygen species accumulation. Mechanistically, LSDV infection activated the PERK-eIF2α-ATF4-CHOP and IRE1α-JNK-BECN1 pathways, indicating induction of ER stress-related signaling. Given the role of AMP-activated protein kinase (AMPK) as a central metabolic stress sensor, we further examined its function during LSDV infection. LSDV infection enhanced AMPK activation, as evidenced by increased phosphorylation of Thr172. Inhibition of energy stress, oxidative stress, or ER stress reduced AMPK phosphorylation to varying degrees, suggesting that multiple stress responses collectively contribute to AMPK activation. Furthermore, AMPK inhibition impaired LSDV replication, while downstream analysis revealed that AMPK activation promotes autophagosome formation. Collectively, these findings demonstrate that LSDV-induced cellular stress responses activate AMPK signaling to facilitate viral replication, providing new insights into host metabolic regulation and identifying AMPK as a potential antiviral target.