TNF-α/cycloheximide-induced oxidative stress and apoptosis in murine intestinal epithelial MODE-K cells

In the mouse postoperative ileus model, we have shown an increase in oxidative stress after intestinal manipulation occurring earlier in the mucosa than in the muscular layer, which might contribute to epithelial barrier dysfunction. To address these findings in vitro, we assessed TNF-α/cycloheximide (CHX)-induced oxidative stress and apoptosis in a mouse intestinal epithelial cell line, MODE-K. The influence of heme oxygenase (HO)-1-related products and agents known to reduce reactive oxygen species (ROS) production on TNF-α/CHX-induced oxidative stress and apoptosis were investigated. MODE-K cells were exposed to different concentrations of TNF- α/CHX in the absence/presence of the test agents. Cell viability, caspase-3/7 activity, apoptosis, reduced glutathione level (GSH) and intracellular ROS production were measured. TNF-α/CHX decreased cell viability, increased caspase-3/7 activity, induced apoptosis, reduced the GSH level and increased ROS production in a concentration-dependent manner in MODE-K cells. All these effects of TNF- α/CHX were partially prevented by pretreatment with a carbon monoxide-releasing agent (CORM-A1) and nitrite. The antioxidant resveratrol abolished TNF-α/CHX-induced increase in ROS production and caspase-3/7 activity, but apoptosis was only partially prevented. MODE-K cells are sensitive to TNF-α-induced apoptosis in the presence of CHX, which is associated with increased intracellular ROS production and caspase-3/7 activation. The effects were partially mitigated by CORM-A1, nitrite and resveratrol. Thus, these agents could be of potential use in protecting the epithelial barrier against oxidative stress during intestinal ischemia/reperfusion injury.