| 1. |
|
|
| 2. |
- Thorlacius, Karin, et al.
(author)
-
Protective effect of fasudil, a Rho-kinase inhibitor, on chemokine expression, leukocyte recruitment, and hepatocellular apoptosis in septic liver injury.
- 2006
-
In: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 79:5, s. 923-931
-
Journal article (peer-reviewed)abstract
- Rho-kinase signaling regulates important features of inflammatory reactions. Herein, we investigated the effect and mechanisms of action of the Rho-kinase inhibitor fasudil in endotoxemic liver injury. C57/BL/6 mice were challenged with lipopolysaccharide (LPS) and D-galactosamine, with or without pretreatment with the Rho-kinase inhibitor fasudil. Six hours after endotoxin challenge, leukocyte-endothelium interactions in the hepatic microvasculature were studied by use of intravital fluorescence microscopy and tumor necrosis factor {alpha} (TNF-{alpha}); CXC chemokines as well as liver enzymes and apoptosis were determined. Administration of fasudil reduced LPS-induced leukocyte adhesion in postsinusoidal venules and sequestration in sinusoids. Moreover, we found that fasudil abolished extravascular infiltration of leukocytes as well as production of TNF-{alpha} and CXC chemokines in the liver of endotoxemic mice. Liver enzymes and hepatocellular apoptosis were markedly reduced, and sinusoidal perfusion was improved significantly in endotoxemic mice pretreated with fasudil. Our novel data document that fasudil is a potent inhibitor of endotoxin-induced expression of TNF-{alpha} and CXC chemokines as well as leukocyte infiltration and hepatocellular apoptosis in the liver. Based on the present findings, it is suggested that inhibition of the Rho-kinase signaling pathway may be a useful target in the treatment of septic liver injury.
|
|
| 3. |
- Awla, Darbaz, et al.
(author)
-
Lymphocyte function antigen-1 regulates neutrophil recruitment and tissue damage in acute pancreatitis.
- 2011
-
In: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 163, s. 413-423
-
Journal article (peer-reviewed)abstract
- Background and purpose: Leucocyte infiltration is a rate-limiting step in the pathophysiology of acute pancreatitis (AP) although the adhesive mechanisms supporting leucocyte-endothelium interactions in the pancreas remain elusive. The aim of this study was to define the role of lymphocyte function antigen-1 (LFA-1) in regulating neutrophil-endothelium interactions and tissue damage in severe AP. Experimental approach: Pancreatitis was induced by retrograde infusion of sodium taurocholate into the pancreatic duct in mice. LFA-1 gene-targeted mice and an antibody directed against LFA-1 were used to define the role of LFA-1. Key results: Taurocholate challenge caused a clear-cut increase in serum amylase, neutrophil infiltration, CXCL2 (macrophage inflammatory protein-2) formation, trypsinogen activation and tissue damage in the pancreas. Inhibition of LFA-1 function markedly reduced taurocholate-induced amylase levels, accumulation of neutrophils, production of CXC chemokines and tissue damage in the pancreas. Notably, intravital microscopy revealed that inhibition of LFA-1 abolished taurocholate-induced leucocyte adhesion in postcapillray venules of the pancreas. In addition, pulmonary infiltration of neutrophils was attenuated by inhibition of LFA-1 in mice challenged with taurocholate. However, interference with LFA-1 had no effect on taurocholate-induced activation of trypsinogen in the pancreas. Conclusions and Implications: Our novel data suggest that LFA-1 plays a key role in regulating neutrophil recruitment, CXCL2 formation and tissue injury in the pancreas. Moreover, these results suggest that LFA-1-mediated inflammation is a downstream component of trypsinogen activation in the pathophysiology of AP. Thus, we conclude that targeting LFA-1 may be a useful approach to protect against pathological inflammation in the pancreas.
|
|
| 4. |
- Braun, Oscar, et al.
(author)
-
Primary and secondary capture of platelets onto inflamed femoral artery endothelium is dependent on P-selectin and PSGL-1.
- 2008
-
In: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 592, s. 128-132
-
Journal article (peer-reviewed)abstract
- Platelets constitute a key role in vascular injuries, however, the detailed mechanisms behind platelet-endothelial cell and platelet-leukocyte interactions in the femoral artery are not yet fully elucidated. We used intravital fluorescence microscopy of the femoral artery in C57BL/6 mice to study primary and secondary capture of platelets onto endothelial cells as well as onto adherent platelets and leukocytes in vivo. By use of monoclonal antibodies, the role of P-selectin and P-selectin glycoprotein ligand 1 (PSGL-1) in these adhesive interactions in mice exposed to endotoxin was determined. Intravenous injection of endotoxin significantly increased gene expression of P-selectin as well as platelet tethering, rolling and adhesion in the femoral artery. Pretreatment with the anti-PSGL-1 antibody decreased platelet tethering by 85%, platelet rolling by 88% and platelet adhesion by 96%. Immunoneutralization of P-selectin reduced platelet tethering by 91%, platelet rolling by 98%, and platelet adhesion by 97%. In addition, inhibition of P-selectin and PSGL-1 completely abolished secondary capture of platelets onto adherent platelets and leukocytes. Our data show that P-selectin and PSGL-1 mediate early interactions between platelets and other cells, including endothelial cells and leukocytes, in inflamed arteries. These novel results suggest that interference with P-selectin and PSGL-1 may be a useful target in strategies aiming to protect the vascular wall during arterial inflammation.
|
|
| 5. |
- Dold, Stefan, et al.
(author)
-
Cholestatic liver damage is mediated by lymphocyte function antigen-1-dependent recruitment of leukocytes.
- 2008
-
In: Surgery. - : Elsevier BV. - 1532-7361 .- 0039-6060. ; 144:3, s. 385-393
-
Journal article (peer-reviewed)abstract
- BACKGROUND: The role of specific adhesion molecules in cholestasis-induced leukocyte recruitment in the liver is not known. Therefore, the aim of our experimental study was to evaluate the role of lymphocyte function antigen-1 (LFA-1) in cholestatic liver injury. METHODS: C57BL/6 mice underwent bile duct ligation for 12 hours. Mice were pretreated with an anti-LFA-1 antibody or control antibody. Subsequently, hepatic accumulation of leukocytes and sinusoidal perfusion were determined by means of intravital fluorescence microscopy. Hepatocellular damage was monitored by measuring serum levels of alanine aminotransferase and aspartate aminotransferase. CXC chemokines in the liver were determined by enzyme-linked immunosorbent assay. RESULTS: Bile duct ligation provoked clear-cut recruitment of leukocytes and liver damage, as indicated by increased serum activities of liver enzymes and sinusoidal perfusion failure. Neutrophils expressed greater levels of LFA-1 and inhibition of LFA-1 significantly decreased serum activity of alanine aminotransferase and aspartate aminotransferase levels in cholestatic mice. Immunoneutralization of LFA-1 reduced leukocyte adhesion in postsinusoidal venules that had been induced by bile duct ligation, whereas leukocyte rolling and sinusoidal accumulation were not changed. Moreover, blocking LFA-1 function restored sinusoidal perfusion in cholestatic animals. CONCLUSION: These findings demonstrate an important role of LFA-1 in supporting cholestasis-induced leukocyte recruitment in the liver. Thus, targeting LFA-1 may help to protect against pathologic inflammation and liver damage in cholestatic liver diseases.
|
|
| 6. |
- Dold, Stefan, et al.
(author)
-
P-selectin glycoprotein ligand-1-mediated leukocyte recruitment regulates hepatocellular damage in acute obstructive cholestasis in mice.
- 2010
-
In: Inflammation Research. - : Springer Science and Business Media LLC. - 1420-908X .- 1023-3830. ; 59, s. 291-298
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Leukocytes mediate hepatocellular injury in obstructive cholestasis. The aim of the present study was to define the role of P-selectin glycoprotein ligand-1 (PSGL-1) in cholestasis-induced leukocyte recruitment and liver damage. METHODS: C57BL/6 mice were pre-treated with an anti-PSGL-1 antibody or a control antibody prior to bile duct ligation (BDL) for 12 h. Hepatic recruitment of leukocytes and sinusoidal perfusion were determined by means of intravital fluorescence microscopy. Liver damage was monitored by measuring serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Hepatic levels of CXC chemokines were determined by ELISA. RESULTS: BDL caused significant hepatocellular damage indicated by increased serum activities of ALT and AST as well as decreased sinusoidal perfusion and clear-cut hepatic infiltration of leukocytes. Administration of the anti-PSGL-1 antibody reduced BDL-induced levels of ALT by 78% and AST by 77%. Inhibition of PSGL-1 decreased BDL-provoked leukocyte rolling and adhesion in post-sinusoidal venules by more than 81%. Moreover, we found that immunoneutralisation of PSGL-1 restored sinusoidal perfusion and decreased hepatic formation of CXC chemokines in cholestatic mice. CONCLUSIONS: Our novel data show that PSGL-1 plays an important role in cholestatic liver damage by regulating leukocyte rolling in post-sinusoidal venules. Consequently, interference with PSGL-1 attenuates cholestasis-provoked leukocyte adhesion and extravasation in the liver. Thus, inhibition of PSGL-1 may help to protect against hepatocellular damage in cholestatic diseases.
|
|
| 7. |
- Klintman, Daniel, et al.
(author)
-
Leukocyte recruitment in hepatic injury: selectin-mediated leukocyte rolling is a prerequisite for CD18-dependent firm adhesion.
- 2002
-
In: Journal of Hepatology. - 0168-8278. ; 36:1, s. 53-59
-
Journal article (peer-reviewed)abstract
- Background/Aims: This study was designed to examine the role of selectins and CD18 in leukocyte recruitment in hepatic injury induced by tumor necrosis factor-alpha (TNF-alpha) and galactosamine (Gal) in vivo.Methods: Intravital fluorescence microscopy of the hepatic microcirculation was used to quantify leukocyte-endothelium interactions provoked by 24 h of systemic TNF-alpha/Gal challenge in rats. Hepatic injury was evaluated with liver enzymes.Results: When administered after 24 h of TNF-alpha/Gal challenge, fucoidan, a selectin-function inhibitor, reduced leukocyte rolling by 69%, whereas firm adhesion was unaltered. In contrast, passive immunization against CD18 decreased leukocyte adhesion by 60%, whereas rolling remained unchanged. Notably, when administered prior to TNF-alpha/Gal, fucoidan attenuated both leukocyte rolling and adhesion, by 57 and 69%, respectively. Pretreatment with an anti-CD18 antibody decreased TNF-alpha/Gal-induced rolling and firm adhesion by 25 and 90%, respectively. Moreover, pretreatment with fucoidan and the anti-CD18 antibody both protected against TNF-alpha/Gal-induced increases in liver enzymes. For example, the pretreatments reduced alanine aminotransferase by 59 and 87%, respectively.Conclusions: Our data suggest that TNF-alpha/Gal-induced leukocyte rolling is selectin-mediated and a precondition for CD18-dependent firm adhesion in hepatic venules. Thus, reducing leukocyte recruitment by inhibition of selectins or CD18 may be useful to control TNF-alpha-induced liver injury.
|
|
| 8. |
- Laschke, Matthias, et al.
(author)
-
Rho-Kinase Inhibitor Attenuates Cholestasis-Induced CXC Chemokine Formation, Leukocyte Recruitment, and Hepatocellular Damage in the Liver.
- 2010
-
In: The Journal of surgical research. - : Elsevier BV. - 1095-8673 .- 0022-4804. ; 159, s. 666-673
-
Journal article (peer-reviewed)abstract
- BACKGROUND: In the present experimental study, we analyzed the role of Rho-kinase during obstructive cholestasis by studying the effect of the Rho-kinase inhibitor Y-27632 on hepatic CXC chemokine formation, leukocyte recruitment and hepatocellular damage. MATERIALS AND METHODS: C57BL/6 mice underwent bile duct ligation (BDL) to induce obstructive cholestasis. Mice were pretreated with Y-27632 (1 and 10mg/kg) or the vehicle PBS. Sham-operated animals served as controls. After 12h, hepatic accumulation of leukocytes and sinusoidal perfusion were determined using intravital fluorescence microscopy. Hepatocellular damage was monitored by measuring serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). CXC chemokines in the liver were analyzed by ELISA. RESULTS: Administration of 10mg/kg of Y-27632 protected against cholestasis-induced hepatocellular damage indicated by a more than 87% reduction of ALT and AST in BDL mice. Moreover, this Rho-kinase inhibitor significantly decreased BDL-induced production of CXC chemokines by 44-83% and leukocyte recruitment by 60%. Finally, treatment with Y-27632 restored sinusoidal perfusion in cholestatic animals. CONCLUSIONS: Our findings indicate that the Rho-kinase signaling pathway plays a key role in the pathophysiology of cholestatic liver injury. Thus, targeting Rho-kinase activity may represent a new therapeutic approach in the treatment of inflammation and liver injury in cholestatic liver diseases.
|
|
| 9. |
- Laschke, Matthias, et al.
(author)
-
The Rho-kinase inhibitor Y-27632 inhibits cholestasis-induced platelet interactions in the hepatic microcirculation.
- 2009
-
In: Microvascular Research. - : Elsevier BV. - 1095-9319 .- 0026-2862. ; 78, s. 95-99
-
Journal article (peer-reviewed)abstract
- Bile duct obstruction is associated with hepatic accumulation of leukocytes and liver injury. Emerging data suggest that platelets may play an important role in tissue damage and inflammation. Herein, we characterized the platelet response in cholestatic liver injury and evaluated the role of Rho-kinase signaling. For this purpose, C57BL/6 mice were treated with the Rho-kinase inhibitor Y-27632 (10 mg/kg) and vehicle before undergoing bile duct ligation (BDL) for 12 h. Platelet rolling and adhesion, formation of platelet aggregates as well as microvascular perfusion in the liver were analyzed using intravital fluorescence microscopy. Liver damage was monitored by measuring serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Administration of Y-27632 reduced the BDL-associated increase of ALT and AST by 95% and 89%, respectively. The inhibition of Rho-kinase also reduced cholestasis-induced platelet rolling and adhesion by more than 46% and 73% in postsinusoidal venules and platelet adhesion in sinusoids by 60%. In addition, Y-27632 decreased platelet aggregation in hepatic sinusoids and postsinusoidal venules by 69% and 81%. BDL caused a significant reduction of hepatic microvascular perfusion. Importantly, pretreatment with Y-27632 restored sinusoidal perfusion in cholestatic animals. Our findings demonstrate that Rho-kinase regulates multiple aspects of platelet interaction in the microcirculation of cholestatic animals. Moreover, inhibition of Rho-kinase signaling not only attenuates platelet responses but also maintains microvascular perfusion and protects against hepatocellular injury in cholestasis. Thus, targeting Rho-kinase signaling may be an effective way to protect against platelet-mediated liver injury in obstructive jaundice.
|
|
| 10. |
- Laschke, Mattias W, et al.
(author)
-
Sepsis-associated cholestasis is critically dependent on P-selectin-dependent leukocyte recruitment in mice.
- 2007
-
In: American Journal of Physiology: Gastrointestinal and Liver Physiology. - : American Physiological Society. - 1522-1547 .- 0193-1857. ; 292, s. 1396-1402
-
Journal article (peer-reviewed)abstract
- 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-alpha 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-alpha and CXC chemokine concentrations, leukocyte infiltration, liver enzyme release, and apoptotic cell death. This response was associated with pronounced cholestasis indicated by a > 70% decrease of bile flow and biliary excretion of bromosulfophthalein. Immunoneutralization of P-selectin significantly attenuated endotoxin- induced leukocyte infiltration reflected by a > 60% reduction of hepatic myeloperoxidase levels. Interference with P-selectin decreased endotoxin- mediated hepatocellular apoptosis and necrosis, but did not affect hepatic levels of tumor necrosis factor-alpha and CXC chemokines. Of interest, inhibition of P- selectin restored bile flow and biliary excretion of bromosulfophthalein to normal levels in endotoxin- challenged animals. Our study demonstrates for the first time that P-selectin-mediated recruitment of leukocytes, but not the local production of proinflammatory mediators, is the primary cause of cholestasis in septic liver injury.
|
|
