These blood cells, in the presence of PMN, cross the epithelium and alter fluid homeostasis, states study in JCI.
Investigators at the University of Colorado Denver School of Medicine have discovered that platelets help promote bacterial clearance under inflammatory conditions.
In the study platelets were found to be able to efficiently pass through a monolayer of intestinal epithelial cells only when polymorphonuclear leukocytes (PMN) were also present and able to cross.
Similar comigration of platelets and PMNs was observed in intestinal tissue from human patients with inflammatory bowel disease. Further studies, in vitro and in a mouse model of intestinal inflammation, indicated that platelets that crossed the epithelial cells triggered epithelial cell secretion of chloride ions and therefore water into the intestine.
The mechanism underlying this effect involved platelet release of large amounts of ATP, which was then broken down to adenosine by proteins such as CD73 and ecto-NTPDases on the surface of epithelial cells.
The study appears in the Journal of Clinical Investigation.