The regulation of paracellular transport via tight junction modulators has not been fully revealed yet. Inhibition of transmembrane serine protease, matriptase found on the epithelial cell surface and in carcinogenic cells leads to decreased resistance of the epithelium presumably via the altered operation of tight junction assembly. The alterations in barrier integrity can be attributed to active interplay between extracellular and intracellular Ca2+ level. The resistance of cell monolayer can be influenced by the effect of low Ca2+ level after application of Ca2+ chelators on tight junctional Ca2+- dependent protein components. The malfunction of this delicately controlled coordination over Ca2+ homeostasis can trigger the sequences of intracellular events such as activation of protein kinases contributing to changed phosphorylation patterns of tight and adherent junctional proteins. The aim of this study is to develop a non-transformed porcine intestinal epithelial cell model cultured on polyester membrane inserts, which can be applied for in vitro investigation of permeability through IPEC-J2 cell monolayer based on the rate of transport processes for paracellular marker, fluorescently labelled dextran between apical and basolateral compartments. The effect of Ca2+ withdrawal and the consequence of modulation of matriptase activity on permeability and barrier integrity of epithelial cell monolayer is of key importance for in-depth understanding the altered functions of inflammed mucosa in vivo.
Research Topics Modelling and regulation of paracellular transport processes through porcine small intestine using IPEC-J2 model system