Mechanistic insights into ROS induction by Clostridium perfringens epsilon toxin in MDCK cells

Epsilon toxin (ETX) is a pore-forming toxin produced by Clostridium perfringens toxinotypes B and D, an anaerobic, Gram-positive, spore-forming bacillus. ETX is considered the third most potent bacterial toxin. This toxin causes severe enteritis in young calves, foals, lambs, and piglets, as well as enterotoxemia in sheep, goats, and occasionally in cattle. The effects induced by ETX on the central nervous system (CNS) of sheep have been extensively studied. The aim of this work was to characterize the mechanism of ETX-induced cytotoxicity in Madin-Darby canine kidney (MDCK) cells. Our results suggest that cytotoxicity may be associated with the generation of reactive oxygen species (ROS), and that pretreatment with inhibitors and antioxidants attenuates this effect. Additionally, the oxidative damage induced by the toxin in MDCK cells may be associated with the activation of nitric oxide synthase (NOS), myeloperoxidase (MPO), the ERK pathway, and mitochondrial oxidative phosphorylation. Inhibition of the ERK pathway resulted in the greatest reduction in MDCK cell death. These findings provide novel information on the mechanism of action of ETX, which may lead to future investigations that relate and help clarify the role of ETX in different pathologies.