Strategies for protecting enterocytes from oxidative stressinduced inflammation

Abstract

The oxidative stress via causing cell and tissue damage can lead to formation of acute and chronic inflammation. Intestinal epithelium acts as a strong physical and chemical barrier against invading bacteria, toxins, oxidative stress and various chemical agents. Malfunction of the epithelial defense mechanisms as a result of damaged gut mucosa and altered intestinal microbial homeostasis can easily lead to leaky gut syndrome which can influence the general health condition of animals even on optimal nutritional regimens. The first aim of this experimental work was the development of an in vitro system mimicking intestinal epithelium, where oxidative stimuli can be introduced by peroxide treatment and the regulatory effect of acute oxidative stress can be monitored continuously. The prerequisite for finding the optimal dose and treatment time of peroxide administration was the maintenance of cell viability whereas the changes in relative gene expression level of proinflammatory cytokines could indicate the acute phase of inflammatory processes. IPECJ2 cells isolated from the jejunum of a neonatal piglet were selected for in vitro study as their glycosylation pattern, proliferation rate and colonisation ability can characterize better the in vivo conditions in the gut ecosystem. The high transepithelial electrical resistance value of IPEC-J2 monolayers grown on collagen-coated polyester membrane inserts demonstrated the functional integrity of the continuous cell association, acting as a single-layer tight physical barrier separating apical and basolateral compartments in the 3D model system .