Increased P-selectin gene expression in the liver vasculature and its role in the pathophysiology of neutrophil-induced liver injury in murine endotoxin shock (original) (raw)
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Hepatology, 1999
Hepatic damage following ischemia-reperfusion injury involves polymorphonuclear leukocytes (PMN) and platelet sequestration, however the mechanisms of adhesion remain elusive. In this study, using gene-targeted deficient mice, we evaluated P-selectin and its contribution to PMN and platelet adhesion in hepatic damage. In an in vivo warm ischemia model, hepatic injury was assessed by serum transaminase levels, survival, PMN adhesion by histological analysis, and platelet sequestration by immunostaining. Serum transaminase levels were strikingly reduced (by up to threefold) in the P-selectin deficient mice, particularly at 90 minutes of ischemia, when compared with wild-type controls. PMN adhesion and platelet sequestration was also significantly decreased in P-selectin deficient mice following 90 minutes of partial ischemia. Animal survival was significantly improved after 75 minutes of total hepatic ischemia in P-selectin deficient mice when compared with wild-type mice. Survival was also achieved after 90 minutes of ischemia in the mutant mice whereas none of the wild-type animals survived. These data show that P-selectin plays a critical role in PMN and platelet adhesion following ischemia-reperfusion injury to the liver. (HEPATOLOGY 1999; 29:1494-1502.)
Concanavalin-A-induced liver injury is severely impaired in mice deficient in P-selectin
Journal of leukocyte biology, 2002
P-selectin (CD62P) is an adhesion molecule that mediates the initial attachment of leukocytes to activated platelets and endothelial cells in damaged tissues. We evaluated the role of P-selectin in concanavalin A (Con A)-induced hepatitis, a model characterized by CD4(+) T cell activation and infiltration of the liver. Con A injection induced transient P-selectin expression on hepatic venules and platelets. Mice lacking P-selectin showed impaired lymphocyte adhesion to liver venules and sinusoids, a striking reduction in intrasinusoidal occlusion, and decreased lymphocyte infiltration of liver parenchyma. The reduction in transaminase levels and the almost complete abolition of necrotic injury demonstrated that liver damage was lower in P-selectin-deficient mice. In wild-type mice, pretreatment with the P-selectin-blocking monoclonal antibody attenuated the sinusoidal occlusion and reduced the rise in transaminases after Con A treatment. These results implicate P-selectin in the dev...
American Journal of Physiology-Lung Cellular and Molecular Physiology, 1999
The role of leukocyte adhesion molecules in endotoxin-induced organ injury was evaluated by administering intraperitoneal Salmonella enteritidislipopolysaccharide (LPS) to wild-type (WT) mice, P-selectin-deficient mice, intercellular adhesion molecule (ICAM)-1-deficient mice, and P-selectin-ICAM-1 double-mutant mice. In WT mice, there was a sevenfold increase in the number of neutrophils present in the pulmonary vascular lavage fluid, and there were sevenfold more intracapillary neutrophils by electron-microscopic (EM) morphometry at 4 h after intraperitoneal LPS compared with that in control mice. Extravascular albumin accumulation increased approximately twofold in the lungs and liver of WT mice treated with LPS. In the double-mutant mice, although overall mortality after intraperitoneal LPS was not attenuated, there was a significant delay in mortality in the P-selectin-ICAM-1-deficient mutants compared with that in WT mice after intraperitoneal LPS ( P < 0.01). Moreover, comp...
Role of P-selectin expression in hepatic ischemia and reperfusion injury
Clinical Transplantation, 1999
of P-selectin expression in hepatic ischemia and reperfusion injury. Clin Transplantation 1999: 13: 76 -82. © Munksgaard, 1999 Abstract: Background. Researchers have shown that reperfusion of ischemic tissues initiates a complex series of reactions that paradoxically injure tissues. Although several mechanisms have been proposed to explain the pathobiology of ischemic/reperfusion (I/R) injury, much attention has focused on adhesion molecules. Our research is intended to show the kinetics of P-selectin in the liver in response to I/R injury. Methods. Left-lobar hepatic ischemia was induced for 30 min in 35 C57BL-6 mice and 20 P-selectin-deficient (K-O) mice. P-selectin expression was measured in these mice at 20 min, 2, 5, 12 and 24 h reperfusion times, as well as in control and sham animals. The animals were injected with radio-labeled P-selectin monoclonal antibody and the organs were harvested for counts/g tissue, expressed as the percentage injected dose. Serum liver enzymes were measured and pathological sections of ischemic and control livers were performed. The unpaired t-test was used for statistical analysis. Results. P-selectin expression showed two peaks in this animal model. The first peak was at 20 min and the second peak at 5 h of reperfusion (p B 0.001). We documented an 8-fold increase in aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels 10 h following I/R injury. Pathological specimens showed periportal necrosis consistent with an ischemic event. P-selectin K-O mice showed no up-regulation as a separate control group, and the liver enzymes were significantly lower than the wild-type mice at 10 h (pB 0.001). Conclusion. P-selectin has a bimodal expression following hepatic I/R injury. The first peak is attributed to the Weibel-Palade bodies and the second to new translational P-selectin. We noted no difference in the up-regulation of P-selectin in the ischemic and non-ischemic liver lobes in the same animal.
Journal of the American College of Surgeons, 2000
Background: P-selectin plays a major role in the earliest phase of polymorphonuclear neutrophil recruitment in the hepatic microvasculature after liver ischemia and reperfusion. Leukocyte cytokine chemoattractants (chemokines) cause polymorphonuclear neutrophil activation in ischemia and reperfusion injury. In this study, we examined the role of P-selectin in the production of chemokines in the liver and lung inflammatory response after 90 minutes of warm ischemia.
Journal of Experimental Medicine, 1999
Resuscitation from hemorrhage induces profound pathophysiologic alterations and activates inflammatory cascades able to initiate neutrophil accumulation in a variety of tissues. This process is accompanied by acute organ damage (e.g., lungs and liver). We have previously demonstrated that significant leukocyte–endothelium interactions occur very early in other forms of ischemia/reperfusion (i.e., splanchnic ischemia/reperfusion and traumatic shock) which are largely mediated by increased expression of the adhesion molecule, P-selectin, on the vascular endothelium. Here we postulated that increased endothelial expression of P-selectin in the microvasculature would play an essential role in initiating the inflammatory signaling of hemorrhagic shock. Using intravital microscopy, we found that hemorrhagic shock significantly increased the number of rolling and adherent leukocytes in the mouse splanchnic microcirculation. In contrast, mice genetically deficient in P-selectin, or wild-typ...
AJP: Gastrointestinal and Liver Physiology, 2006
Cholestasis is a major complication in sepsis although the underlying mechanisms remain elusive. The aim of this study was to evaluate the role of P-selectin and leukocyte recruitment in endotoxemia-associated cholestasis. C57BL/6 mice were challenged intraperitoneally with endotoxin (0.4 mg/kg), and 6 h later the common bile duct was cannulated for determination of bile flow and biliary excretion of bromosulfophthalein. Mice were pretreated with an anti-P-selectin antibody or an isotype-matched control antibody. Leukocyte infiltration was determined by measuring hepatic levels of myeloperoxidase. Tumor necrosis factor-α and CXC chemokines in the liver was determined by ELISA. Liver damage was monitored by measuring serum levels of alanine aminotransferase and aspartate aminotransferase. Apoptosis was quantified morphologically by nuclear condensation and fragmentation using Hoechst 33342 staining. Endotoxin induced a significant inflammatory response with increased TNF-α and CXC ch...
Differing Patterns of P-Selectin Expression in Lung Injury
The American Journal of Pathology, 1998
In the immune complex model , upregulation of P-selectin was defined by Northern and Western blot analysis of lung homogenates , by immunostaining of lung tissue , and by vascular fixation of 125 I-labeled anti-Pselectin. P-selectin protein was detected by 1 hour (long before detection of mRNA) and expression was sustained for the next 7 hours , in striking contrast to the pattern of P-selectin expression in the cobra venom factor model , in which upregulation was very transient (within the 1st hour). In the immune complex model , injury and neutrophil accumulation were P-selectin dependent. Upregulation of P-selectin was dependent on an intact complement system , and the presence of blood neutrophils was susceptible to the antioxidant dimethyl sulfoxide and required C5a but not tumor necrosis factor ␣. In contrast , in the cobra venom factor model , upregulation of P-selectin, which is C5a dependent , was also dimethyl sulfoxide sensitive but neutrophil independent. Different mechanisms that may explain why upregulation of lung vascular P-selectin is either transient or sustained are discussed.
P-selectin mediates leukocyte rolling in concanavalin-A-induced hepatitis
Liver International, 2005
Concanavalin-A (Con-A)-induced hepatitis is an experimental model of human autoimmune hepatitis characterized by leukocyte activation and infiltration of the liver. The aim of the present study was to evaluate the role of P-selectin on leukocyte-endothelial interactions within the hepatic microvasculature in response to Con-A. Methods: The study was performed in P-selectin-deficient mice and wild-type mice pretreated with anti-P-selectin blocking monoclonal antibody (mAb) or vehicle. After 2 h of Con-A (20 mg/ kg i.v.) or PBS administration, leukocyte rolling and adhesion and the index of sinusoidal perfusion were evaluated using the intravital microscopy technique in the liver. Apoptosis was determined by flow cytometry analysis of caspase-3 activity assayed on freshly isolated hepatocytes. Results: Con-A induced a significant increase in leukocyte rolling, mainly located at the central venule (2.1 AE 0.4 vs 0.6 AE 0.2 cells/min in wild-type mice treated with vehicle) and less marked, but still significant, in portal venules. This was associated with a significant increase in leukocyte adhesion. In P-selectindeficient mice treated with Con-A, leukocyte rolling in portal and central venules was markedly reduced. However, leukocyte adhesion was only partially attenuated. A few sinusoids were perfused in wild-type mice treated with Con-A (26%). The percentage of perfused sinusoids was significantly higher in P-selectin-deficient mice (45%; Po0.05 vs wild-type). Similar effects were noted after the simultaneous injection of Con-A and anti-P-selecting mAb in wild-type mice. After Con-A treatment, apoptosis was markedly reduced in isolated hepatocytes of P-selectin-deficent mice (37 AE 7% vs 75 AE 5% in wild type). Conclusion: The results of this intravital microscopy study clearly demonstrate that P-selectin is involved in the initial leukocyte rolling that leads to the development of Con-A-induced liver injury.