Pharmacological inhibition of cytokine synthesis with CPSI-2364 ameliorates ischemia reperfusion injury (IRI) after small bowel transplantation (SBTx)

Abstract

Background: Resident macrophages within the tunica muscularis are known to play a crucial role in initiating ischemia reperfusion injury (IRI) after SBTx contributing to graft dysmotility and bacterial translocation. Therefore we investigated the effects of inhibition of macrophages cytokine releasing pathway on IRI in SBTx by treating with CPSI-2364. Materials and methods: Orthotopic isogenic SBTx was performed in rats (Lewis-Lewis). Recipient and donor animals were treated perioperatively with CPSI-2364 (1 mg/kg, i.v.). Non-transplanted native animals and vehicle treated animals served as control groups (n=8). Animals were sacrificed 3 h and 18 h after reperfusion. Park’s score was used for histological grading. Leukocyte infiltration was investigated by immunohistochemistry and histochemistry, apoptosis by TUNEL-staining and mediator expression by Real-Time-RT-PCR, ELISA and Griess reaction. Smooth muscle contractility was assessed in a standard organ bath under bethanechol stimulation. Statistics consisted of analysis of variance (ANOVA). Results: Treatment with CPSI-2364 results in significant less leukocyte (ED1, MPO) infiltration and amelioration of graft dysmotility 18 h after reperfusion compared to vehicle treated group. Proinflammatory cytokines and kinetic active mediators were significantly decreased 3h after reperfusion whereas no significant differences were detectable after 18 h. Histologic evaluation revealed protective effects of treatment with CPSI-2364 at all timepoints. Conclusion: Early inflammatory processes in the tunica muscularis in SBTx due to ischemia reperfusion injury initiated by activated macrophages are leading to impaired graft motor function. Preoperative treatment with CPSI-2364 provides protection from IRI with reduced inflammation and graft dysmotility after isogenic SBTx.