| 1. |
- Liu, Qing, et al.
(författare)
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Linomide and antibody-targeted superantigen therapy abolishes formation of liver metastases in mice.
- 2003
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Ingår i: European Surgical Research. - : S. Karger AG. - 0014-312X .- 1421-9921. ; 35:6, s. 457-463
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Tidskriftsartikel (refereegranskat)abstract
- Hematogenous spread of tumor cells and metastasis formation in the liver are insidious aspects of cancer progression and are not frequently amenable to curative treatment. We examined the effect of Linomide and antibody-targeted therapy against the formation of hepatic metastases in vivo. For this purpose, syngenic B16 melanoma cells transfected with GA733-2 (a human colon cancer cell surface antigen) were injected into a mesenteric vein of C57/Bl6 mice. To test bacterial superantigen (Sag) targeting for immunotherapy of liver metastases, we used genetically fused proteins consisting of SEA and a Fab moiety of a GA733-2 tumor-reactive antibody (C215Fab-SEA). Linomide dose-dependently reduced hepatic metastases, and at 300 mg/kg this reduction was more than 80%. Treatment with C215Fab-SEA decreased metastases formation by 49% and the combination of Linomide and C215Fab-SEA was found to completely abolish liver metastases (>99% reduction). Taken together, our novel data suggest that Linomide and antibody-targeted superantigen therapy individually markedly reduce and together abolish liver metastases. Considering that current therapy of hepatic metastases is mainly limited to surgical resection in a subgroup of patients, these findings indicate that Linomide alone or in combination with antibody-targeted superantigen may provide a novel approach against liver metastases.
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| 2. |
- Zhang, X W, et al.
(författare)
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Important role of CD18 in TNF-alpha-induced leukocyte adhesion in muscle and skin venules in vivo
- 2000
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Ingår i: Inflammation Research. - : Springer Science and Business Media LLC. - 1420-908X .- 1023-3830. ; 49:10, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To examine the role of CD 18 in tumor necrosis factor-alpha (TNF-alpha)-induced leukocyte adhesion and extravasation in vivo. MATERIAL: Male wild-type (WT) and mutated mice with hypomorphic expression of CD 18. METHODS: Intravital microscopy was used to quantitate leukocyte-endothelium interactions provoked by TNF-alpha (0.5 microg) in the cremaster muscle and dorsal skin microcirculation. Tissue recruitment of leukocytes was evaluated in wholemounts of the cremaster muscle and in air pouches in the dorsal skin after TNF-alpha stimulation. RESULTS: TNF-alpha markedly increased venular leukocyte adhesion and recruitment in the cremaster muscle and skin in WT. Notably, in CD 18-targeted animals, leukocyte adhesion triggered by TNF-alpha challenge was significantly reduced by 58% and 72% in venules of the cremaster muscle and skin, respectively. Moreover, in CD18-mutants, tissue accumulation of polymorphonuclear leukocytes (PMNLs) provoked by TNF-alpha in the muscle and skin was decreased by 84% and 70%, respectively. Interestingly, the observed level of reduction in TNF-alpha-induced neutrophil adhesion and recruitment in CD18 gene-targeted animals corresponded well with the decrease in CD 18 expression on neutrophils from these mice, i.e. the surface density of CD18 was reduced by 77% in mutants compared to WT. Differential analysis revealed that the extravascular leukocytes comprised more than 90% PMNLs, indicating that neutrophils were the main inflammatory cell responding to TNF-alpha activation. Notably, the expression of CD18 increased by more than two-fold on extravasated neutrophils compared to circulating neutrophils in the peripheral blood both in WT and mutant animals. CONCLUSIONS: These findings suggest that CD18 is a dominant mediator of firm neutrophil adhesion to venular endothelial cells in the muscle and skin stimulated by TNF-alpha in vivo. In addition, this decreased adhesion in CD18-mutants attenuates leukocyte extravasation in response to TNF-alpha activation. Thus, inhibition of CD 18-function may provide an important strategy to inhibit leukocyte recruitment in cytokine-dependent diseases.
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| 3. |
- Li, Xiang, et al.
(författare)
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Critical role of CXC chemokines in endotoxemic liver injury in mice.
- 2004
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Ingår i: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 75:3, s. 443-452
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Tidskriftsartikel (refereegranskat)abstract
- Tissue accumulation of leukocytes constitutes a rate-limiting step in endotoxin-induced tissue injury. Chemokines have the capacity to regulate leukocyte trafficking. However, the role of CXC chemokines, i.e., macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (KC), in leukocyte recruitment, microvascular perfusion failure, cellular injury, and apoptosis in the liver remains elusive. Herein, mice were challenged with lipopolysaccharide (LPS) in combination with D-galactosamine, and intravital microscopy of the liver microcirculation was conducted 6 h later. It was found that immunoneutralization of MIP-2 and KC did not reduce LPS-induced leukocyte rolling and adhesion in postsinusoidal venules. In contrast, pretreatment with monoclonal antibodies against MIP-2 and KC abolished (83% reduction) extravascular recruitment of leukocytes in the livers of endotoxemic mice. Notably, endotoxin challenge increased the expression of CXC chemokines, which was mainly confined to hepatocytes. Moreover, endotoxin-induced increases of liver enzymes and hepatocellular apoptosis were decreased by more than 82% and 68%, respectively, and sinusoidal perfusion was restored in mice passively immunized against MIP-2 and KC. In conclusion, this study indicates that intravascular accumulation of leukocytes in the liver is independent of CXC chemokines in endotoxemic mice. Instead, our novel data suggest that CXC chemokines are instrumental in regulating endotoxin-induced transmigration and extravascular tissue accumulation of leukocytes. Indeed, these findings demonstrate that interference with MIP-2 and KC functions protects against septic liver damage and may constitute a potential therapeutic strategy to control pathological inflammation in endotoxemia.
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| 4. |
- Liu, Qing, et al.
(författare)
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Roquinimex inhibits dextran sodium sulfate-induced murine colitis
- 2003
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Ingår i: Inflammation Research. - : Springer Science and Business Media LLC. - 1420-908X .- 1023-3830. ; 52:2, s. 64-68
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Roquinimex is a modulator of the immune system and has been shown to attenuate induction of several inflammatory and autoimmune diseases. The objective of the present study was to determine the efficacy of roquinimex in a model of murine colitis. Materials and methods: For this purpose, Balb/c mice were exposed to 5% dextran sodium sulfate (DSS) in the drinking water for five to six days. Roquinimex (300 mg kg(-1) day(-1)) was administered by subcutaneous (s.c.) injection 3 days prior to and throughout the treatment period with DSS. In separate experiments, 300 mg kg(-1) day(-1) of roquinimex was given therapeutically after initiation of DSS challenge. Results: DSS provoked clinical signs of colitis, reduced crypt height (CH) and increased mucosal damage score (MDS) as analyzed by histology. In addition, challenge with DSS increased the colonic content of myeloperoxidase (MPO). Prophylactic administration of DSS-treated mice with roquinimex significantly reduced clinical signs of colitis, MDS and the CH-reduction. Moreover, in roquinimex treated animals, the MPO activity was significantly reduced by more than 50% compared to DSS control mice. Notably, therapeutic administration of roquinimex in DSS-treated mice also significantly inhibited the MDS, CH-reduction and MPO activity. Conclusions: These findings suggest that roquinimex strongly inhibits murine colitis and may provide a novel pharmacological approach to treat inflammatory bowel disease.
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| 5. |
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| 6. |
- Wan, M X, et al.
(författare)
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Protective effect of low molecular weight heparin on experimental colitis: role of neutrophil recruitment and TNF-alpha production.
- 2002
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Ingår i: Inflammation Research. - 1420-908X. ; 51:4, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The purpose of this study was to examine the impact and mechanism of action of low molecular weight heparin (LMWH) in a model of murine colitis. MATERIALS AND METHODS: Balb/c mice were exposed to 5% dextran sodium sulfate (DSS) in the drinking water for five days. LMWH (500 units/kg/day) was administered by subcutaneous injection prior to and throughout the treatment period with DSS. Clinical disease activity index (DAI), including body weight loss, stool consistency and blood in feces were examined daily. Moreover, crypt height (CH), mucosal damage score (MDS), myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-alpha) content in the colon were determined. RESULTS: DSS increased DAI, MDS, MPO activity and TNF-alpha production and decreased CH. Administration of LMWH markedly reduced DAI, MDS and reversed the CH-reduction. Moreover, in LMWH-treated animals, the MPO activity was reduced by more than 67% whereas mucosal levels of TNF-alpha was similar compared to DSS control mice. CONCLUSIONS: These findings suggest that LMWH inhibits murine colitis by interference with neutrophil recruitment and that LMWH may provide a novel pharmacological approach to treatment of inflammatory bowel disease.
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| 7. |
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| 8. |
- Zawadzki, Antoni, et al.
(författare)
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Verapamil Inhibits L-type Calcium Channel Mediated Apoptosis in Human Colon Cancer Cells.
- 2008
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Ingår i: Diseases of the Colon & Rectum. - : Ovid Technologies (Wolters Kluwer Health). - 0012-3706. ; 51, s. 1696-1702
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Treatment with calcium channel blockers have been associated with increased colon cancer mortality in epidemiologic studies. We examined the potential expression and function of calcium channels in two human colon cancer cell lines. METHODS: Both primary (collected at operation) and commercially-available human colon cancer cell lines were used. The colon cancer cells were incubated with a calcium channel blocker (verapamil) and a calcium channel agonist (BayK 8644) at clinically relevant concentrations. L-type calcium channel mRNA was determined by reverse-transcription polymerase chain reaction. Intracellular calcium ion levels were measured with fluorometry and apoptosis with flow cytometry. RESULTS: Both types of cells expressed L-type calcium channel mRNA, comprising an alpha-1D and a beta-3 subunit, whereas the cells were negative for N-type and P-type channels. The selective calcium channel agonist (BayK 8644), dose-dependently increased intracellular calcium ion levels and the level of apoptosis in primary human colon cancer cells. Pretreatment with verapamil completely abolished both calcium channel agonist-induced influx of calcium and apoptosis in these cells. CONCLUSIONS: These data demonstrate that human colon cancer cells express L-type calcium channels that mediate calcium influx and apoptosis, which warrants further studies to determine whether calcium channel blockers may promote colon cancer growth.
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| 9. |
- Zhang, X.W., et al.
(författare)
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Inhibition of selectin function and leukocyte rolling protects against dextran sodium sulfate-induced murine colitis
- 2001
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 36:3, s. 270-275
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Tidskriftsartikel (refereegranskat)abstract
- Background: The selectin family of adhesion molecules (P-, E- and L-selectin) plays an important role in inflammatory reactions by mediating interactions between leukocytes and activated endothelial cells. However, a recent study using gene-targeted mice has suggested that adhesion molecules (P- and E-selectin and ICAM-1) may not be relevant targets in intestinal inflammation. The objective of the present study was to re-evaluate the potential role of selectins in experimental colitis in wild-type mice using the polysaccharide fucoidan, which inhibits the function of P- and L-selectin. Methods: For this purpose, Balb/c mice were exposed to 5% dextran sodium sulfate (DSS) in the drinking water for 5 days with and without daily administration of fucoidan (25 mg/kg, i.v.). In separate experiments, the effect of fucoidan on leukocyte-endothelium interactions was examined by use of intravital microscopy. Results: It was found that pretreatment with fucoidan (25 mg/kg/day) reduced mucosal damage and crypt destruction in the colon of DSS-treated mice. Moreover, this fucoidan treatment markedly reduced the colonic MPO activity in mice exposed to DSS. In vivo microscopy revealed that the dose of fucoidan used in the present study abolished TNF-alpha -induced venular leukocyte rolling and extravascular recruitment. Conclusions: These results suggest that selectins mediate leukocyte infiltration and tissue damage in experimental colitis. Moreover, our data support: the concept that functional interference with adhesion molecules of the selectin family may have a beneficial effect in the treatment of inflammatory bowel disease.
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