Published online Aug 28, 2021. doi: 10.3748/wjg.v27.i32.5404
Peer-review started: April 24, 2021
First decision: June 3, 2021
Revised: June 17, 2021
Accepted: July 30, 2021
Article in press: July 30, 2021
Published online: August 28, 2021
Processing time: 122 Days and 19.2 Hours
Intestinal barrier breakdown, a frequent complication of intestinal ischemia-reperfusion (I/R) including dysfunction and the structure changes of the intestine, is characterized by a loss of tight junction and enhanced permeability of the intestinal barrier and increased mortality. To develop effective and novel therapeutics is important for the improvement of outcome of patients with intestinal barrier deterioration. Recombinant human angiopoietin-like protein 4 (rhANGPTL4) is reported to protect the blood-brain barrier when administered exogenously, and endogenous ANGPTL4 deficiency deteriorates radiation-induced intestinal injury.
To identify whether rhANGPTL4 may protect intestinal barrier breakdown induced by I/R.
Intestinal I/R injury was elicited through clamping the superior mesenteric artery for 60 min followed by 240 min reperfusion. Intestinal epithelial (Caco-2) cells and human umbilical vein endothelial cells were challenged by hypoxia/ reoxygenation to mimic I/R in vitro.
Indicators including fluorescein isothiocyanate-conjugated dextran (4 kilodaltons; FD-4) clearance, ratio of phosphorylated myosin light chain/total myosin light chain, myosin light chain kinase and loss of zonula occludens-1, claudin-2 and VE-cadherin were significantly increased after intestinal I/R or cell hypoxia/reoxygenation. rhANGPTL4 treatment significantly reversed these indicators, which were associated with inhibiting the inflammatory and oxidative cascade, excessive activation of cellular autophagy and apoptosis and improvement of survival rate. Similar results were observed in vitro when cells were challenged by hypoxia/reoxygenation, whereas rhANGPTL4 reversed the indicators close to normal level in Caco-2 cells and human umbilical vein endothelial cells significantly.
rhANGPTL4 can function as a protective agent against intestinal injury induced by intestinal I/R and improve survival via maintenance of intestinal barrier structure and functions.
Core Tip: Improving therapy on intestinal barrier dysfunction induced by ischemia/ reperfusion is still challenging. Most recently, studies indicated that patients who suffered from coronavirus disease 2019 are associated with intestinal hypoperfusion. We investigated the effect of recombinant human angiopoietin-like protein 4 on intestinal barrier structure and function deterioration using intestinal ischemia/ reperfusion models in rats as well as hypoxia/reoxygenation models in cells. Intestinal barrier indicators associated with the inflammatory and oxidative cascade, excessive activation of cellular autophagy and apoptosis were compared. Our results indicated that recombinant human angiopoietin-like protein 4 behaved as a promising therapeutic agent for intestinal ischemia/reperfusion-induced intestine injury.