AMP-activated protein kinase–Caspase 6 axis regulation alleviates the combined apoptotic damage caused by deoxynivalenol and fumonisin B1 in mammary glands

Deoxynivalenol (DON) and fumonisin B1 (FB1) are prevalent mycotoxins commonly found together in dairy cow feed, posing significant risks to cow health and food safety. This study investigates combined toxic effects of DON and FB1 on bovine mammary epithelial cells (BMECs), and role of AMPK-Caspase 6 axis in mycotoxin-induced apoptosis in BMECs and mouse model. We showed that even subcytotoxic doses of DON, combined with FB1, induced synergistic or additive toxic effects, reducing cell viability, increasing LDH release, and promoting apoptosis. This combination also impaired milk triglyceride synthesis and downregulated genes involved in milk fat and protein production. Silencing Caspase 6 via siRNA, inhibiting with Z-VEID-FMK, or activating AMPK with AICAR alleviated apoptosis. Conversely, overexpressing Caspase 6 diminished AMPK's protective effects. In vivo, inhibiting Caspase 6 alleviated apoptosis in mammary tissues. These findings highlight therapeutic potential of targeting the AMPK-Caspase 6 pathway to mitigate combined toxicity of DON and FB1.