Submitted on October 10, 2005
Accepted on April 4, 2006
LIPOPOLYSACCHARIDE-BINDING PROTEIN MODULATES HEPATIC DAMAGE AND THE INFLAMMATORY RESPONSE AFTER HEMORRHAGIC SHOCK AND RESUSCITATION
Mark Lehnert1, Tetsuya Uehara2, Blair U Bradford3, Henrik Lind1, Zhong Zhi3, David Allen Brenner4, Ingo Marzi5, and John J Lemasters3*
1 Department of Cell Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States; Department of Trauma-, Hand- and Reconstructive Surgery, Hospitals of the J.W. Goethe University, Frankfurt, Germany
2 Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States; Department of Surgery, Yamatotakada Municipal Hospital, Yamatotakada City, Japan
3 Department of Cell Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
4 Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States; Department of Medicine, Columbia University, New York, New York, United States
5 Department of Trauma-, Hand- and Reconstructive Surgery, Hospitals of the J.W. Goethe University, Frankfurt, Germany
* To whom correspondence should be addressed. E-mail: lemaster{at}med.unc.edu.
Hemorrhagic shock and resuscitation cause endotoxemia and hepatocellular damage. Since LPS-binding protein (LBP) enhances cellular responses to endotoxin, our aim was to determine if LBP contributes to hemorrhage/resuscitation-induced injury by comparing LBP knockout and wild-type mice. Under pentobarbital anaesthesia, wild-type and LBP deficient mice were hemorrhaged to 30 mm Hg for 3 h and then resuscitated with shed blood plus half the volume of lactated Ringers solution. Serum ALT necrosis, neutrophil infiltration and 4-hydroxynonenal by histology/cytochemistry, and stress kinase activation by immunoblotting were then determined. ALT in wild-type mice was 2461±383 (mean±S.E.) and 1418±194 IU/L, respectively at 2 and 6 h after resuscitation vs. sham ALT of 102±6 IU/L. In LBP deficient mice, ALT was blunted at both time points to 1108±340 and 619±171 IU/L (p<0.05). Liver necrosis after 6 h was also attenuated from 3.5±0.8% in wild-type mice to 1.3±0.5% in LBP deficient mice (p<0.05). After hemorrhage/resuscitation, neutrophil infiltration increased 71% more in wild type than LBP knockout mice. Similarly, hepatic 4-hydroxynonenal staining, indicative of lipid peroxidation, decreased from 33.8±4.5% in wild-type mice to 11.6±1.9% in knockout mice (p<0.05). After hemorrhage/resuscitation, activation of MAP kinases, JNK and Erk, occurred in wild-type mice, which was largely blocked in LBP deficient mice. However, endotoxin in portal blood after resuscitation was not significantly different between wild-type and knockout mice. In conclusion, hemorrhagic shock and resuscitation to mice cause severe, LBP-mediated hepatocellular damage. Absence of LBP blunts hepatocellular injury with decreased neutrophil infiltration, oxidative stress, and c-Jun and Erk activation.
