A Glial Cell Inhibitor Blocks Epithelial Barrier Repair in a Pig Model of Intestinal Ischemia

Abstract

The gut epithelium functions as a barrier against toxic luminal contents which can repair efficiently after injury to prevent systemic illness and death. However, we have shown that repair is severely hindered in neonates as compared to juveniles in our translational pig model of intestinal ischemia. The subepithelial enteric glial cell (EGC) network is known to promote epithelial repair by paracrine signaling mechanisms. This EGC network develops postnatally; therefore, we believe this repair defect in neonates is due to an underdeveloped EGC network. In support of this, we hypothesize that EGC inhibition in juveniles will block epithelial barrier repair after ischemic injury mimicking the neonatal phenotype. Ischemia‐injured jejunum of juvenile pigs was recovered ex vivo with and without fluoroacetate (FA), a glial inhibitor. Transepithelial electrical resistance (TEER) was monitored as a measure of barrier function, and tissues were collected for imaging analysis and primary EGC culture. FA inhibited TEER recovery at all tested concentrations (P<0.0001). Histology showed 500μM FA optimally inhibits epithelial repair (P=0.0196) without directly damaging the epithelium (P=0.5509). Cellular metabolism marker c‐fos has been optimized for immunofluorescence in control tissues and ongoing imaging work will validate selective inhibition of EGC metabolism by 500μM FA. In addition, pig EGC isolation and culture has been optimized, so that future work will confirm inhibitory effects of FA on EGC signaling functions in vitro. Understanding the development of glial‐epithelial crosstalk in barrier repair will ultimately guide novel clinical solutions to improve outcomes in neonatal patients affected by intestinal injury.Support or Funding InformationUNC CGIBD Large Animal Models Core (P30 DK034987), UNC CGIBD Basic Science Research Training Fellowship (NIH T32 5T32DK007737), UNC CGIBD Pilot Feasibility Grant (P30 DK034987), USDA National Institute of Food and Agriculture (Projects 1007263 and 07985)