FTY720 Effects on Inflammation and Liver Damage in a Rat Model of Renal Ischemia-Reperfusion Injury

OBJECTIVE: Ischemia-reperfusion injury (IRI) produces systemic inflammation with the potential for causing organ failure in tissues peripheral to the initial site of injury. We speculate that treatment strategies that dampen inflammation may be therapeutically beneficial to either the initial site of injury or peripheral organs. To test this, we evaluated the impact of FTY720-induced sequestration of circulating mature lymphocytes on renal IRI and secondary organ injury. METHODS: A microvascular clamp was surgically placed around the left renal pedicle of anesthetized male Sprague-Dawley rats with either vehicle or FTY720 treatment (0.3 mg/kg) intravenously injected after 15 min of ischemia. Blood flow was restored after 60 min. Cohorts of anesthetized rats were euthanized at 6, 24, or 72 hrs with tissue samples collected for analysis. RESULTS: FTY720 treatment resulted in profound T lymphocyte reduction in peripheral blood. Histopathologic examination, clinical chemistries, and gene transcript expression measurements revealed that FTY720 treatment reduced hepatocellular degeneration, reduced serum markers of liver injury (ALT/AST), and reduced the expression of gene targets associated with IRI. CONCLUSION: These findings support an anti-inflammatory effect of FTY720 in the liver where the expression of genes associated with apoptosis, chemotaxis, and the AP-1 transcription factor was reduced. Findings presented here provide the basis for future studies evaluating FTY720 as a potential therapeutic agent to treat complications resulting from renal IRI.