Goblet cell compound exocytosis in the defense against bacterial invasion in the colon exposed to ischemia-reperfusion.

In recent years, the importance of the mucus layer in the colon has become increasingly clear. Disturbance of the mucus layer has been implicated in a variety of intestinal diseases. We have recently investigated the importance of the mucus layer in colon ischemia-reperfusion (IR). Using a newly developed human and rat colon IR model, we showed that colon ischemia leads to mucus barrier breakdown. This allowed intraluminal bacteria to interact with the colonic epithelium, which was associated with an inflammatory response. Intriguingly, we found goblet cells to respond immediately by expelling their mucin granules into the gut lumen, which flushed bacteria from the colonic crypts and resulted in rapid restoration of the mucus layer during reperfusion. Our study might explain why ischemic colitis tends to have favorable outcomes and can often be treated conservatively.