Deoxynivalenol Impairs Porcine Intestinal Barrier Function and Decreases the Protein Expression of Claudin-4 through a Mitogen-Activated Protein Kinase-Dependent Mechanism ,

Abstract

Deoxynivalenol (DON) is a common mycotoxin that contaminates cereals and their by-products. The gastrointestinal tract is the first physical barrier against ingested food contaminants. DON contributes to the loss of barrier function of the intestine through the decreased expression of claudin-4 protein, a tight junction protein. The mechanism by which DON alters the intestinal barrier function remains poorly characterized. Therefore, we investigated the involvement of mitogen-activated protein kinases (MAPK) in the DON-induced loss of barrier function. We first verified that 30 μmol/L of DON activated MAPK in a highly sensitive porcine intestinal epithelial cell line (IPEC-1). Inhibition of p44/42 extracellular signal-regulated kinase (ERK) phosphorylation, with 0.5 μmol/L of the specific MAPK pharmacological inhibitor U0126 for 2 h, restored the barrier function of the differentiated intestinal epithelial cell monolayers. The restoration of barrier function was evaluated by trans-epithelial electrical resistance measurements and tracer flux paracellular permeability experiments. The U0126 also restored the intestinal expression of claudin-4 protein, thereby demonstrating that MAPK activation is involved in claudin-4 protein expression and claudin-4 is involved in the maintenance of the intestinal epithelial cell barrier function. Further experiments indicated that p44/42 ERK is not involved in the transcriptional regulation of claudin-4. In conclusion, we demonstrated that DON-induced activation of the p44/42 ERK signaling pathway inhibits the expression of claudin-4 protein, which leads to impaired intestinal barrier function. Given the high levels of DON in cereal grains, these observations of impaired barrier function have implications for human and animal health.

Toxicological interactions between the mycotoxins deoxynivalenol, nivalenol and their acetylated derivatives in intestinal epithelial cells

“…The non-transformed porcine IPeC-1 cell line has been broadly used as an in vitro model for pig intestinal epithelium functionalities, to assess mycotoxins and especially fusariotoxins toxicity (Goossens et al 2012;Loiseau et al 2007;Pinton et al 2010). This cell line is known to retain most of its original epithelial nature, which makes it possible to extrapolate the results of the in vitro trials to the in vivo situations (Brosnahan and Brown 2012;De vos et al 2012).…”

“…H. m. Berschneider and D. D. Black. The IPeC-1 cells were maintained as previously described (Pinton et al 2010). In brief, the IPeC-1 cells were grown at pig physiological internal body temperature (39 °C), 5 % CO 2 , in complete Dmem/F-12 medium (eurobio) supplemented with antibiotics, 5 % FBs, 2 mm l-glutamine, epidermal growth factor (5 μg/l; Becton-Dickinson, Le Pont de Claix, France), and ITs solution (insulin (5 μg/ml), transferrin (5 μg/ml), selenium (5 ng/ml)).…”

Pathogenesis of Inflammatory Bowel Diseases

“…Indeed, several studies, cell line cultures and isolated crypts from human biopsies, have shown that it is not only over-expressed in IBD tissue (both colonocytes and cells in the underlying lamina propria), but that its phosphorylation state and therefore activation state is increased significantly during the active stages of IBD (Waetzig et al, 2002;Dahan et al, 2008). Study also found that Erk activation is involved in claudin-4 protein expression and claudin-4 is involved in the maintenance of the intestinal epithelial cell barrier function (Pinton et al, 2010) as a "tightening" junction protein. Activation of p38/MAPK and Akt signal transduction pathways in the epithelial cells have also been implicated as key mediators of these protective effects (Resta-Lenert & Barrett.…”

Protein Kinases and Ulcerative Colitis

“…Indeed, several studies, cell line cultures and isolated crypts from human biopsies, have shown that it is not only over-expressed in IBD tissue (both colonocytes and cells in the underlying lamina propria), but that its phosphorylation state and therefore activation state is increased significantly during the active stages of IBD (Waetzig et al2002;Dahan et al2008). Study also found that Erk activation is involved in claudin-4 protein expression and claudin-4 is involved in the maintenance of the intestinal epithelial cell barrier function (Pinton et al 2010) as a "tightening" junction protein. Activation of p38/MAPK and Akt signal transduction pathways in the epithelial cells have also been implicated as key mediators of these protective effects (Resta-Lenert and Barrett.…”