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iNOS inhibition as a target in arthritis, inflammation and angiogenesis
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14th IVBM Abstracts
2 mRNA expression and stimulated a small increase in the size of HA secreted into the medium. Inhibition of the PKC pathway caused a 50% decrease in thrombin stimulated proteoglycan synthesis, but had a smaller effect on HA synthesis. As some GPCR agonists can signal through transactivation of the EGF receptor, we inhibited EGFR activation using AG 1478. This compound inhibited thrombin stimulated proteoglycan synthesis and size by 50%, however it caused a complete inhibition of thrombin stimulated HA synthesis. Thus thrombin stimulates previously unrecognized pro-atherogenic effects on two components of the extracellular matrix.
special importance in the field of DES technology, mainly at the scenario of stents overlap. doi:10.1016/j.vph.2006.08.074
A1.21 iNOS inhibition as a target in arthritis, inflammation and angiogenesis J. Bainbridge1, L. Madden1, M. Binks2, R. Malhotra2, E. Paleolog1
doi:10.1016/j.vph.2006.08.073 1
Kennedy Institute of Rheumatology, Imperial College, London, United Kingdom 2 GlaxoSmithKline, Stevenage, United Kingdom
A1.20 Impaired pathological and transcriptional responses after local delivery of paclitaxel, but not rapamycin, to abolish restenosis Nuno M.M. Pires1, Daniel Eefting1, Margreet de Vries1, Paul H.A. Quax1, J. Wouter Jukema2 1 2
TNO-Quality of Life, Leiden, Nederland Leiden University Medical Center, Leiden, Nederland
Drug-eluting stents (DES) have been successfully introduced in clinical practice to prevent post-angioplasty restenosis. Nevertheless, DES long term safety-related issues on vascular integrity and vessel wall toxicity are still unclear. Here, we assess the vascular responses to rapamycin and paclitaxel on a murine model of restenosis in an atherosclerotic background. Atherosclerotic-like lesions were induced by placement of a perivascular cuff around the femoral artery of hypercholesterolemic ApoEȄ3-Leiden transgenic mice. Two weeks later these cuffs were replaced either by rapamycin- or paclitaxel-eluting cuffs. Evaluation of local delivery of rapamycin and paclitaxel was assessed after two additional weeks. Both rapamycin and paclitaxel significantly inhibited restenosis development. Vascular histopathological and real time RT-PCR analysis revealed that local delivery of rapamycin to inhibit restenosis has no adverse affect on vascular pathology. Conversely, paclitaxel treatment significantly increased apoptosis, internal elastic lamina fracture, and extensively decreased medial and intimal smooth muscle cell and collagen content. Moreover, vascular transcriptional analysis showed increase levels of pro-apoptotic mRNA transcripts (i.e. FAS, BAX, Caspase 3) and a decrease of SM-actin mRNA levels in the paclitaxel-treated arteries. Both rapamycin and paclitaxel are effective in preventing restenosis. Rapamycin has no significant effect on arterial pathology. In contrast, paclitaxel possesses a narrower therapeutic window as equated to rapamycin, as demonstrated by adverse vascular pathology and transcriptional responses. This might be of
Inducible nitric oxide synthase (iNOS) is a potential therapeutic target in rheumatoid arthritis (RA). To evaluate both the relevance of iNOS inhibition to RA and the mechanism(s) of action, we set out to examine if a specific iNOS inhibitor (GW274150) could reduce inflammation and joint destruction in our collagen induced arthritis animal model of RA.DBA/1 male mice were immunised with bovine collagen type II in complete Freund's adjuvant intra-dermally at the base of the tail. Mice were monitored for signs of arthritis and treated with 0.5, 1.5 or 5 mg/ kg/day of GW274150 upon disease onset. During treatment, mice were examined for paw swelling and assigned a clinical score, based on the severity of arthritis and number of limbs affected. Variance between treatments was analysed using a 2 way ANOVA. Treatment with GW274150 at 0.5, 1.5 or 5 mg/kg/day significantly reduced disease severity compared to vehicle treated controls. These results were further corroborated by histological analysis of arthritic paws in GW274150-treated animals, in which semi-quantitative examination showed a reduction in inflammation and joint damage again compared to vehicle-treated controls. To examine an underlying mechanism for iNOS inhibition, we attempted to identify target cell phenotypes for GW274150. Initially, iNOS inhibition in endothelial cells was assessed using human umbilical vein endothelial cells (HUVEC), which showed no significant effect of GW274150 on proliferation stimulated with endothelial cell mitogens FGF-2, VEGF and EGF. Furthermore, there was no evidence of GW274150 altering cell viability and cytokine release compared to normal controls. Murine bone marrow derived macrophages were then examined as an alternative target for iNOS inhibition. There was a significant reduction in VEGF (p < 0.05) and TNF (p < 0.05) release in GW274150 treated wells (10 μM) compared to LPS only controls. This study provides evidence for the therapeutic potential of iNOS inhibition. Although the vasculature may not be a direct target, angiogenic signaling cytokines produced by macrophages may be down regulated as a result of iNOS inhibition. This work was sponsored by GSK. doi:10.1016/j.vph.2006.08.075
14th IVBM Abstracts
2 mRNA expression and stimulated a small increase in the size of HA secreted into the medium. Inhibition of the PKC pathway caused a 50% decrease in thrombin stimulated proteoglycan synthesis, but had a smaller effect on HA synthesis. As some GPCR agonists can signal through transactivation of the EGF receptor, we inhibited EGFR activation using AG 1478. This compound inhibited thrombin stimulated proteoglycan synthesis and size by 50%, however it caused a complete inhibition of thrombin stimulated HA synthesis. Thus thrombin stimulates previously unrecognized pro-atherogenic effects on two components of the extracellular matrix.
special importance in the field of DES technology, mainly at the scenario of stents overlap. doi:10.1016/j.vph.2006.08.074
A1.21 iNOS inhibition as a target in arthritis, inflammation and angiogenesis J. Bainbridge1, L. Madden1, M. Binks2, R. Malhotra2, E. Paleolog1
doi:10.1016/j.vph.2006.08.073 1
Kennedy Institute of Rheumatology, Imperial College, London, United Kingdom 2 GlaxoSmithKline, Stevenage, United Kingdom
A1.20 Impaired pathological and transcriptional responses after local delivery of paclitaxel, but not rapamycin, to abolish restenosis Nuno M.M. Pires1, Daniel Eefting1, Margreet de Vries1, Paul H.A. Quax1, J. Wouter Jukema2 1 2
TNO-Quality of Life, Leiden, Nederland Leiden University Medical Center, Leiden, Nederland
Drug-eluting stents (DES) have been successfully introduced in clinical practice to prevent post-angioplasty restenosis. Nevertheless, DES long term safety-related issues on vascular integrity and vessel wall toxicity are still unclear. Here, we assess the vascular responses to rapamycin and paclitaxel on a murine model of restenosis in an atherosclerotic background. Atherosclerotic-like lesions were induced by placement of a perivascular cuff around the femoral artery of hypercholesterolemic ApoEȄ3-Leiden transgenic mice. Two weeks later these cuffs were replaced either by rapamycin- or paclitaxel-eluting cuffs. Evaluation of local delivery of rapamycin and paclitaxel was assessed after two additional weeks. Both rapamycin and paclitaxel significantly inhibited restenosis development. Vascular histopathological and real time RT-PCR analysis revealed that local delivery of rapamycin to inhibit restenosis has no adverse affect on vascular pathology. Conversely, paclitaxel treatment significantly increased apoptosis, internal elastic lamina fracture, and extensively decreased medial and intimal smooth muscle cell and collagen content. Moreover, vascular transcriptional analysis showed increase levels of pro-apoptotic mRNA transcripts (i.e. FAS, BAX, Caspase 3) and a decrease of SM-actin mRNA levels in the paclitaxel-treated arteries. Both rapamycin and paclitaxel are effective in preventing restenosis. Rapamycin has no significant effect on arterial pathology. In contrast, paclitaxel possesses a narrower therapeutic window as equated to rapamycin, as demonstrated by adverse vascular pathology and transcriptional responses. This might be of
Inducible nitric oxide synthase (iNOS) is a potential therapeutic target in rheumatoid arthritis (RA). To evaluate both the relevance of iNOS inhibition to RA and the mechanism(s) of action, we set out to examine if a specific iNOS inhibitor (GW274150) could reduce inflammation and joint destruction in our collagen induced arthritis animal model of RA.DBA/1 male mice were immunised with bovine collagen type II in complete Freund's adjuvant intra-dermally at the base of the tail. Mice were monitored for signs of arthritis and treated with 0.5, 1.5 or 5 mg/ kg/day of GW274150 upon disease onset. During treatment, mice were examined for paw swelling and assigned a clinical score, based on the severity of arthritis and number of limbs affected. Variance between treatments was analysed using a 2 way ANOVA. Treatment with GW274150 at 0.5, 1.5 or 5 mg/kg/day significantly reduced disease severity compared to vehicle treated controls. These results were further corroborated by histological analysis of arthritic paws in GW274150-treated animals, in which semi-quantitative examination showed a reduction in inflammation and joint damage again compared to vehicle-treated controls. To examine an underlying mechanism for iNOS inhibition, we attempted to identify target cell phenotypes for GW274150. Initially, iNOS inhibition in endothelial cells was assessed using human umbilical vein endothelial cells (HUVEC), which showed no significant effect of GW274150 on proliferation stimulated with endothelial cell mitogens FGF-2, VEGF and EGF. Furthermore, there was no evidence of GW274150 altering cell viability and cytokine release compared to normal controls. Murine bone marrow derived macrophages were then examined as an alternative target for iNOS inhibition. There was a significant reduction in VEGF (p < 0.05) and TNF (p < 0.05) release in GW274150 treated wells (10 μM) compared to LPS only controls. This study provides evidence for the therapeutic potential of iNOS inhibition. Although the vasculature may not be a direct target, angiogenic signaling cytokines produced by macrophages may be down regulated as a result of iNOS inhibition. This work was sponsored by GSK. doi:10.1016/j.vph.2006.08.075