Pancreatic secretory trypsin inhibitor reduces multi-organ injury caused by gut ischemia/reperfusion in mice.

Raymond J Playford,Tania Marchbank,Partha Mukhopadhyay

doi:10.1371/journal.pone.0227059

Abstract

Intestinal ischemia/reperfusion (I/R) injury occurs during transplantation, mesenteric arterial occlusion, trauma and shock, causing systemic inflammation, multiple organ dysfunction and high mortality. Pancreatic secretory trypsin inhibitor (PSTI), a serine protease inhibitor expressed in gut mucosa may function as a mucosal protective/repair peptide. We examined whether PSTI affected mesenteric I/R-induced injury. Hypoxia/normoxia (H/N) caused 50% drop in cell viability of AGS, RIE1 and Caco-2 cells but PSTI (10 μg/ml) given prior- or during-hypoxic period improved survival by 50% (p<0.01). Similarly, Caco-2 monolayers exposed to H/N had 300% increase in transepithelial permeability, PSTI truncated this by 50% (p<0.01). Mice underwent mesenteric I/R by clamping jejunum, causing severe mucosal injury, increased apoptotic markers and 3-fold increases in plasma IL-6, IL1β, TNFα, and tissue lipid peroxidation (MDA) and inflammatory infiltration (MPO) levels. Lungs showed similar significant injury and inflammatory infiltrate markers. Smaller increases in MDA and MPO were seen in kidney & liver. PSTI (20 mg/kg) reduced all injury markers by 50–80% (p<0.01). In vitro and in vivo studies showed PSTI reduced pro-apoptotic Caspase 3, 9 and Baxα levels, normalised Bcl2 and caused additional increases in HIF1α, VEGF and Hsp70 above rises caused by I/R alone (all p<0.01). PSTI also prevented reduction of tight junction molecules ZO1 and Claudin1 (all p<0.01) but did not affect increased ICAM-1 caused by I/R in gut or lung. PSTI may be a useful clinical target to prevent I/R injury.

Highlights

Gastrointestinal ischemia/reperfusion (I/R) injury is involved in multiple clinical situations, such as neonatal necrotizing enterocolitis, acute mesenteric ischemia, volvulus, trauma, cardiopulmonary disease, hemorrhagic shock, and intestinal transplant rejection [1,2,3,4]
1A: Dose response study: Cells grown under normoxia showed no change in viability or Lactate dehydrogenase (LDH) if Pancreatic secretory trypsin inhibitor (PSTI) was administered
Cell viability increased from 52 ± 2% to 78 ± 2% (Fig 1A) and the rise in LDH was reduced by 37% ± 2% (Fig 1B)

Summary

Introduction

Gastrointestinal ischemia/reperfusion (I/R) injury is involved in multiple clinical situations, such as neonatal necrotizing enterocolitis, acute mesenteric ischemia, volvulus, trauma, cardiopulmonary disease, hemorrhagic shock, and intestinal transplant rejection [1,2,3,4]. In addition to local tissue injury, remote organs are damaged by the uncontrolled inflammatory response resulting from release of inflammatory mediators and activation of leukocytes due to the post-ischemic gut serving as a priming bed for circulating polymorphonuclear cells [5, 6].

Methods

Results

Conclusion