Staphylococcal enterotoxin A induces DNA damage in hepatocytes and liver tissues

Abstract

Staphylococcal enterotoxin A (SEA) is a foodborne bacterial toxin that can cause food poisoning, but little research has been done on the DNA damage caused by SEA. The aim of this research was to investigate the action of SEA in inducing DNA damage and oxidative stress response in hepatocytes and liver tissues. After treating HL-7702 and BRL-3A cells with different concentrations of SEA (0, 300, 600 ng/mL and 0, 400, 800 ng/mL), the production of phosphorylated H2AX (γH2AX) and p53 binding protein 1 (53BP1) aggregates was detected by confocal fluorescence microscopy, and the increases in ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (Chk2), p53 protein expression were assessed by Western blot analysis, while increased reactive oxygen species (ROS) content was confirmed by flow cytometry and fluorescence probe. The genotoxicity of SEA to cells was attenuated after the addition of an oxidative inhibitor, demonstrating that SEA induced intracellular DNA damage through the oxidative pathway and a dose-dependent relationship was observed between the oxidation index and SEA. These experimental results deepen our understanding of SEA damage to cells at the genetic level, and provide a new orientation for the prevention and cure of food borne diseases caused by Staphylococcal enterotoxins (SEs).