Rat liver injury after normothermic ischemia is prevented by a phosphinic matrix metalloproteinase inhibitor.

Hepatic ischemia occurs in liver transplantation, hemodynamic or cardiogenic shock, and liver resection associated with trauma or tumor. Ischemia/reperfusion (I/R) injury results in microcirculation failure followed by apoptosis and necrosis. Matrix metalloproteinases (MMPs) are involved in many physiological and pathological processes, but their expression and function during liver I/R remains poorly documented. In this study, we evaluated the expression of nine MMPs and their natural inhibitors, tissue inhibitors of MMPs (TIMPs), in a rat model of liver I/R. Analysis of MMP and TIMP expression show that although most of these genes are not constitutively expressed in the normal liver, they are induced in a specific time-dependent manner following I/R. Stromelysin-1, gelatinase B, and collagenase-3 are induced during the early phase of acute liver injury associated with inflammation and increased necrosis/apoptosis, whereas gelatinase A, membrane type-MMP, stromelysin-3, metalloelastase, TIMP-1, and TIMP-2 are essentially detectable during the recovery phase of liver injury corresponding to hepatocyte regeneration. This observation suggested that MMPs and TIMPs could play both deleterious and beneficial roles following I/R. We thus tested the effect of a specific phosphinic MMP inhibitor on acute liver I/R injury. Inhibition of MMP activity was shown to significantly decrease liver injury in ischemic/reperfused liver tissue as assessed by histological studies and serum hepatic enzyme levels. We therefore propose that MMP inhibitors may be of clinical relevance in liver-associated ischemic diseases or after liver transplantation.