Deoxynivalenol impairs porcine intestinal barrier function and decreases the protein expression of claudin-4 through a mitogen-activated protein kinase-dependent mechanism.
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.
Pinton
Philippe
P
Laboratoire de Pharmacologie et Toxicologie UR66, INRA, F-31931 Toulouse, France.
Braicu
Cornelia
C
Nougayrede
Jean-Philippe
JP
Laffitte
Joëlle
J
Taranu
Ionelia
I
Oswald
Isabelle P
IP
D000818:Animals; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D062506:Claudin-4; D015536:Down-Regulation / Q000187:drug effects*; D017097:Electric Impedance; D020895:Enterocytes / Q000187:drug effects / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D005517:Foodborne Diseases / Q000503:physiopathology; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011042:Poisons / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013552:Swine; D019108:Tight Junctions / Q000187:drug effects* / Q000378:metabolism; D014255:Trichothecenes / Q000494:pharmacology*
C568157:CLDN4 protein, human; D062506:Claudin-4; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D011042:Poisons; D012333:RNA, Messenger; D014255:Trichothecenes; D048049:Extracellular Signal-Regulated MAP Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C007262:deoxynivalenol