Effects of nafamostat mesilate, a protease Inhibitor, on ischemia/reperfusion-induced kidney injury in mice

Ischemia is induced when blood flow to an organ is interrupted, and re-establishing blood flow is essential to prevent ongoing hypoxic injury, although it paradoxically imparts further injury. Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has been used in patients undergoing hemodialysis who are at a high risk of bleeding. To determine the protective effect of NM on ischemia-reperfusion injury (IRI) in a mouse renal IRI model, NM was administered as a pre- and post-treatment or during ischemia reperfusion and compared to a control group. Mice were bilaterally nephrectomized and subjected to 40 min of renal pedicle occlusion followed by 24 h reperfusion. NM (240 mu g/kg) significantly improved kidney function and lowered serum creatinine and blood urea nitrogen levels. Consistently, NM inhibited collagen formation in kidney tissues. NM treatment attenuated the effects of ischemia/reperfusion on kidney tissues and significantly inhibited activation of Tolllike receptor 4, nuclear factor kappa-light-chainenhancer of activated B cells-phospho-65 (NF-kBp65), phospho-inhibitor of NF-kappa beta a, and inducible nitric oxide synthase (iNOS). NM treatment also decreased expression of Bcl-2, Caspase-3 and Bax in kidney tissues, which has been linked with induction of apoptosis in kidney tissues. Our studies suggest that NM may be a novel therapeutic agent to prevent and treat kidney IRI, in which iNOS and/or NF-kappa beta are upregulated. The exact regulatory mechanism and its functional significance require further elucidation.