| 1. |
- Thorlacius, Karin, et al.
(författare)
-
Protective effect of fasudil, a Rho-kinase inhibitor, on chemokine expression, leukocyte recruitment, and hepatocellular apoptosis in septic liver injury.
- 2006
-
Ingår i: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 79:5, s. 923-931
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 2. |
- Asaduzzaman, Muhammad, et al.
(författare)
-
Critical role of p38 mitogen-activated protein kinase signaling in septic lung injury.
- 2008
-
Ingår i: Critical Care Medicine. - 1530-0293. ; 36:2, s. 482-488
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Leukocyte-mediated tissue damage is a key feature in septic lung injury, although the signaling mechanisms behind pulmonary recruitment of leukocytes remain elusive. The aim of the present study was to define the role of p38 mitogen-activated protein kinase (MAPK) signaling in septic lung injury. DESIGN: Prospective experimental study. SETTING: University hospital research unit. SUBJECTS: Male C57BL/6 mice. INTERVENTIONS: Pulmonary edema, bronchoalveolar infiltration of leukocytes, levels of myeloperoxidase, and CXC chemokines were determined 6 and 24 hrs after cecal ligation and puncture (CLP). The specific p38 MAPK inhibitors SB 239063 and SKF 86002 were given immediately before CLP induction. Phosphorylation and activity of p38 MAPK were determined by immunoprecipitation and Western blot. MEASUREMENTS AND MAIN RESULTS: CLP induced clear-cut pulmonary damage characterized by edema formation, leukocyte infiltration, and increased levels of CXC chemokines in the lung. Moreover, CLP increased phosphorylation and activity of p38 MAPK in the lung, which was markedly inhibited by SB 239063. Interestingly, inhibition of p38 MAPK signaling protected against CLP-induced lung damage and edema. Indeed, both SB 239063 and SKF 86002 decreased CLP-induced leukocyte recruitment in the bronchoalveolar space and formation of CXC chemokines in the lung. CONCLUSIONS: Our data demonstrate that p38 MAPK signaling constitutes a key role in regulating CXC chemokine production in septic lung injury and that inhibition of p38 MAPK activity abolishes pulmonary infiltration of leukocytes as well as lung edema. These novel findings suggest that targeting the p38 MAPK signaling pathway may pave the way for a new therapeutic strategy against lung injury in polymicrobial sepsis.
|
|
| 3. |
- Asaduzzaman, Muhammad, et al.
(författare)
-
LFA-1 AND MAC-1 MEDIATE PULMONARY RECRUITMENT OF NEUTROPHILS AND TISSUE DAMAGE IN ABDOMINAL SEPSIS.
- 2008
-
Ingår i: Shock. - : Ovid Technologies (Wolters Kluwer Health). - 1540-0514 .- 1073-2322. ; 30, s. 254-259
-
Tidskriftsartikel (refereegranskat)abstract
- Neutrophil-mediated lung damage is an insidious feature in septic patients, although the adhesive mechanisms behind pulmonary recruitment of neutrophils in polymicrobial sepsis remain elusive. The aim of the present study was to define the role of lymphocyte function-antigen 1 (LFA-1) and membrane-activated complex 1 (Mac-1) in septic lung injury. Pulmonary edema, bronchoalveolar infiltration of neutrophils, levels of myeloperoxidase, and CXC chemokines were determined after cecal ligation and puncture (CLP). Mice were treated with monoclonal antibodies directed against LFA-1 and Mac-1 before CLP induction. Cecal ligation and puncture induced clear-cut pulmonary damage characterized by edema formation, neutrophil infiltration, and increased levels of CXC chemokines in the lung. Notably, immunoneutralization of LFA-1 or Mac-1 decreased CLP-induced neutrophil recruitment in the bronchoalveolar space by more than 64%. Moreover, functional inhibition of LFA-1 and Mac-1 abolished CLP-induced lung damage and edema. However, formation of CXC chemokines in the lung was intact in mice pretreated with the anti-LFA-1 and anti-Mac-1 antibodies. Our data demonstrate that both LFA-1 and Mac-1 regulate pulmonary infiltration of neutrophils and lung edema associated with abdominal sepsis. Thus, these novel findings suggest that LFA-1 or Mac-1 may serve as targets to protect against lung injury in polymicrobial sepsis.
|
|
| 4. |
- Braun, Oscar, et al.
(författare)
-
Primary and secondary capture of platelets onto inflamed femoral artery endothelium is dependent on P-selectin and PSGL-1.
- 2008
-
Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 592, s. 128-132
-
Tidskriftsartikel (refereegranskat)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. |
|
|
| 6. |
- Dold, Stefan, et al.
(författare)
-
Cholestatic liver damage is mediated by lymphocyte function antigen-1-dependent recruitment of leukocytes.
- 2008
-
Ingår i: Surgery. - : Elsevier BV. - 1532-7361 .- 0039-6060. ; 144:3, s. 385-393
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 7. |
- Dold, Stefan, et al.
(författare)
-
Simvastatin protects against cholestasis-induced liver injury.
- 2009
-
Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 156, s. 466-474
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Bile duct obstruction is associated with hepatic accumulation of leukocytes and liver injury. The aim of this study was to evaluate the effect of simvastatin on cholestasis-induced liver inflammation and tissue damage. Experimental approach: C57BL/6 mice were treated with simvastatin (0.02 and 0.2 mg.kg(-1)) and vehicle before and after undergoing bile duct ligation (BDL) for 12 h. Leukocyte recruitment and microvascular perfusion in the liver were analysed using intravital fluorescence microscopy. CXC chemokines in the liver were determined by enzyme-linked immunosorbent assay. Liver damage was monitored by measuring serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Hepatic levels of myeloperoxidase (MPO) were also determined. Key results: Administration of 0.2 mg.kg(-1) simvastatin decreased ALT and AST by 87% and 83%, respectively, in BDL mice. This dose of simvastatin reduced hepatic formation of CXC chemokines by 37-82% and restored sinusoidal perfusion in cholestatic animals. Moreover, BDL-induced leukocyte adhesion in sinusoids and postsinusoidal venules, as well as MPO levels in the liver, was significantly reduced by simvastatin. Notably, administration of 0.2 mg.kg(-1) simvastatin 2 h after BDL induction also decreased cholestatic liver injury and inflammation. Conclusions and implications: These findings show that simvastatin protects against BDL-induced liver injury. The hepatoprotective effect of simvastatin is mediated, at least in part, by reduced formation of CXC chemokines and leukocyte recruitment. Thus, our novel data suggest that the use of statins may be an effective strategy to protect against the hepatic injury associated with obstructive jaundice.
|
|
| 8. |
|
|
| 9. |
- Gunnarsson, Peter, 1977-
(författare)
-
α1-acid glycoprotein modulates the function of human neutrophils and platelets
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The acute-phase protein α1-acid glycoprotein (AGP; orosomucoid) was initially identified andcharacterised in the 1950s. The normal plasma concentration is around 0.5-1 mg/ml butduring inflammation the concentration increase several fold and the carbohydrate compositionof the protein changes. AGP is a highly glycosylated protein with 45 % of the molecularweight consisting of glycans. These glycans are believed to be of importance for the functionof the protein. However, the precise physiological role of AGP is still unclear.The present thesis reveals that AGP at physiological concentration induce calcium elevationin human neutrophils and platelets. In neutrophils this response was enhanced several fold ifsurface L-selectin was pre-engaged. Our results showed that this L-selectin-mediatedamplification was abolished if the neutrophils were pre-treated with Src or phosphoinositide3-kinase (PI3K) inhibitors. AGP alone did not induce production of reactive oxygen species(ROS) in neutrophils. However, if the neutrophils were activated by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) a subsequent addition of AGP caused aprominent ROS response. Moreover, both the calcium rise and the ROS response weredepending on sialic acid residues on AGP. In the case of calcium elevation we defined thereceptor as sialic-acid-binding immunoglobulin-like lectin (Siglec)-5 on the neutrophil.In platelets, AGP induced a Rho-kinase dependent phosphorylation of myosin phosphatasetarget subunit-1 (MYPT1) and a minor calcium response. This resulted in a prominent plateletshape change (i.e. spherical shape and granule centralization) recorded as change in lighttransmission and by differential interference contrast (DIC) microscopy. The shape changecaused by AGP was strongly suppressed by inhibition of Rho-kinase and abolished by Rhokinaseinhibition combined with chelation of intracellular calcium. No other manifestations ofplatelet activation like aggregation or secretion were registered. Opposite to neutrophils theeffect of AGP on platelets was not mediated by an interaction between sialic acid and siglecmolecules. However, the results indicated that AGP may bind to a collagen/thrombospondin-1surface receptor. Endogenous inhibitors like nitric oxide (NO) and adenosine abolished theAGP-induced platelet shape change. The antagonizing action of NO on shape change causedby AGP was long acting. In comparison, other aspects of agonist-induced platelet activation(e.g. intracellular calcium elevations) are only transiently suppressed by NO. This indicatesthat endothelium-derived NO may play a crucial role to counter balance the effect of AGP in vivo.Take together the results in this thesis reveal that AGP can initiate intracellular signalling andmodulate functional responses in neutrophils and platelets.
|
|
| 10. |
- Hakansson, A, et al.
(författare)
-
Rose Hip and Lactobacillus plantarum DSM 9843 Reduce Ischemia/Reperfusion Injury in the Mouse Colon.
- 2006
-
Ingår i: Digestive Diseases and Sciences. - : Springer Science and Business Media LLC. - 1573-2568 .- 0163-2116. ; 51:11, s. 2094-2101
-
Tidskriftsartikel (refereegranskat)abstract
- schaemia/reperfusion (I/R) of the colon is an inflammatory condition that leads to tissue injury where reactive oxygen species play a central role. Rose hip is rich in biologically active polyphenols with antioxidative properties, which may be important in prevention of lipid peroxidation. L. plantarum DSM 9843 possesses enzymatic activity towards polyphenols. The objective of this study was to define the effect of oral administration of L. plantarum and rose hip in I/R injury. Administration of rose hip and L. plantarum significantly decreased MDA levels in caecum tissue and Enterobacteriaceae counts in caecum stool. A positive correlation between MDA levels and Enterobacteriaceae counts was found. The results support a synergistic/additive role of rose hip and L. plantarum in reducing lipid peroxidation. Therefore rose hip and L. plantarum may be used as a pretreatment to tissue injuries, e.g. colonic surgery, organ transplantation and vascular surgery.
|
|
