Pathophysiologic Importance of E- and L-Selectin for Neutrophil-Induced Liver Injury During Endotoxemia in Mice

Neutrophils can cause parenchymal cell injury in the liver during ischemia-reperfusion and endotoxemia. Neutrophils relevant for the injury accumulate in sinusoids, transmigrate, and adhere to hepatocytes. To investigate the role of E- and L-selectin in this process, C3Heb/FeJ mice were treated with 700 mg/kg galactosamine and 100 μg/kg endotoxin (Gal/ET). Immunogold labeling verified the expression of E-selectin on sinusoidal endothelial cells 4 hours after Gal/ET injection. In addition, Gal/ET caused up-regulation of Mac-1 (CD11b/CD18) and shedding of L-selectin from circulating neutrophils. Gal/ET induced hepatic neutrophil accumulation (422 ± 32 polymorphonuclear leukocytes [PMN]/50 high power fields [HPF]) and severe liver injury (plasma alanine transaminase [ALT] activities: 4,120 ± 960 U/L; necrosis: 44 ± 3%) at 7 hours. Treatment with an anti–E-selectin antibody (3 mg/kg, intravenously) at the time of Gal/ET administration did not significantly affect hepatic neutrophil accumulation and localization. However, the anti–E-selectin antibody significantly attenuated liver injury as indicated by reduced ALT levels (−84%) and 43% less necrotic hepatocytes. In contrast, animals treated with an anti–L-selectin antibody or L-selectin gene knock out mice were not protected against Gal/ET-induced liver injury. However, E-, L-, and P-selectin triple knock out mice showed significantly reduced liver injury after Gal/ET treatment as indicated by lower ALT levels (−65%) and reduced necrosis (−68%). Previous studies showed that circulating neutrophils of E-selectin–overexpressing mice are primed and activated similar to neutrophils adhering to E-selectin in vitro. Therefore, we conclude that blocking E-selectin or eliminating this gene may have protected against Gal/ET-induced liver injury in vivoby inhibiting the full activation of neutrophils during the transmigration process. (Hepatology 2000;32:990-998.)