Alteration in intestine tight junction protein phosphorylation and apoptosis is associated with increase in IL-18 levels following alcohol intoxication and burn injury.
Li, X Akhtar, S Choudhry, MA
||Li X, etal., Biochim Biophys Acta. 2012 Feb;1822(2):196-203. doi: 10.1016/j.bbadis.2011.09.019. Epub 2011 Oct 7.
||(View Article at PubMed) PMID:22001439
Intestinal mucosal barrier is the first line of defense against bacteria and their products originating from the intestinal lumen. We have shown a role for IL-18 in impaired gut barrier function following acute alcohol (EtOH) intoxication combined with burn injury. To further delineate the mechanism, this study examined whether IL-18 alters intestine tight junction proteins or induces mucosal apoptosis under these conditions. To accomplish this, rats were gavaged with EtOH (3.2g/kg) prior to ~12.5% total body surface area burn or sham injury. One day after injury, EtOH combined with burn injury resulted in a significant decrease in total occludin protein and its phosphorylation in small intestine compared to either EtOH or burn injury alone. There was no change in claudin-1 protein content but its phosphorylation on tyrosine was decreased following EtOH and burn injury. This was accompanied with an increase in mucosal apoptosis (p<0.05). The treatment of rats with anti-IL-18 antibody at the time of burn injury prevented intestine apoptosis and normalized tight junction proteins following EtOH and burn injury. Altogether, these findings suggest that IL-18 modulates tight junction proteins and cause apoptosis leading to impaired intestinal mucosal integrity following EtOH intoxication combined with burn injury.