Effect of intestinal epithelial autophagy on bacterial translocation in severe acute pancreatitis.

Background and Objective: We examined the impact of autophagy activation on bacterial translocation (BT) and tight junction (TJ) proteins in the intestinal mucosa of patients with severe acute pancreatitis (SAP).
Methods: Thirty-one SAP patients were divided into two groups, BT(+) and BT(-), according to the presence of BT in the blood, as detected by 16S rDNA sequencing. Eight healthy individuals were included in the control group. Serum endotoxin levels were measured by ELISA. Colonic mucosal tissue was obtained by endoscopy, and the TJ proteins and phosphatidylethanolamine-conjugated microtubule-associated protein light chain 3 (LC3-II) were analyzed using immunofluorescence and Western blotting.
Results: The expression of LC3II in patients with SAP was higher than that observed in healthy controls. Patients who tested positive for the presence of BT had a higher level of claudins-2 (CL-2) and a lower level of occludin and Zonula occluden-1 (ZO-1) than BT(-) patients. Moreover, the levels of LC3II in BT(-) patients was higher than that found in BT(+) patients, and occludin and ZO-1 were positively correlated with LC3II.
Conclusions: Autophagy activation in the intestinal epithelial cells of patients with SAP and its effects on BT may act through enhancing para-cellular TJs.
(Copyright © 2017 Elsevier Masson SAS. All rights reserved.)