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MAPK Inhibitor SB203580 (mapk + inhibitor_sb203580)
Selected AbstractsSimultaneous flow cytometric detection of basophil activation marker CD63 and intracellular phosphorylated p38 mitogen-activated protein kinase in birch pollen allergy,CYTOMETRY, Issue 1 2009Nicolaas E. Aerts Abstract Background: Phosphorylation of p38 MAPK is a crucial step in IgE-receptor signaling in basophils. The relation of p38 MAPK to the well-validated diagnostic cell surface marker CD63 has not been evaluated in a clinical allergy model. Methods: Expression of CD63 and phosphorylation of p38 MAPK were analyzed flow cytometrically in anti-IgE-gated basophils from 18 birch pollen allergic patients, five grass pollen allergic patients, and five healthy individuals, after 3 and 20 min of stimulation with recombinant major birch pollen allergen (rBet v 1). Additional time points and the influence of p38 MAPK inhibitor SB203580 were studied in birch pollen allergic patients. Results: Phospho-p38 MAPK and CD63 were expressed dose-dependently in birch pollen allergic patient basophils within 1 minute of rBet v 1 stimulation. P38 MAPK phosphorylation was fastest and subsided gradually while CD63 expression remained elevated for at least 20 min. Inhibition of p38 MAPK significantly inhibited CD63 upregulation. With optimal stimulation of the cells (1 ,g/mL), sensitivity and specificity for the discrimination between patients and a group of control individuals (grass pollen allergic patients and healthy controls) were 94% and 100% for CD63 at 3 and 20 min and for phospho-p38 MAPK at 3 min. Conclusion: Antigen-induced p38 MAPK phosphorylation in human basophils essentially contributes to CD63 upregulation. It is a sensitive and specific intracellular marker for allergy diagnosis and offers new insight into the mechanisms of basophil activation. © 2008 Clinical Cytometry Society [source] HSP27 mediates SPARC-induced changes in glioma morphology, migration, and invasionGLIA, Issue 10 2008William A. Golembieski Abstract Secreted protein acidic and rich in cysteine (SPARC) regulates cell,extracellular matrix interactions that influence cell adhesion and migration. We have demonstrated that SPARC is highly expressed in human gliomas, and it promotes brain tumor invasion in vitro and in vivo. To further our understanding regarding SPARC function in glioma migration, we transfected SPARC-green fluorescent protein (GFP) and control GFP vectors into U87MG cells, and assessed the effects of SPARC on cell morphology, migration, and invasion after 24 h. The expression of SPARC was associated with elongated cell morphology, and increased migration and invasion. The effects of SPARC on downstream signaling were assessed from 0 to 6 h and 24 h. SPARC increased the levels of total and phosphorylated HSP27; the latter was preceded by activation of p38 MAPK and inhibited by the p38 MAPK inhibitor SB203580. Augmented expression of SPARC was correlated with increased levels of HSP27 mRNA. In a panel of glioma cell lines, increasing levels of SPARC correlated with increasing total and phosphorylated HSP27. SPARC and HSP27 were colocalized to invading cells in vivo. Inhibition of HSP27 mRNA reversed the SPARC-induced changes in cell morphology, migration, and invasion in vitro. These data indicate that HSP27, a protein that regulates actin polymerization, cell contraction, and migration, is a novel downstream effector of SPARC-regulated cell morphology and migration. As such, it is a potential therapeutic target to inhibit SPARC-induced glioma invasion. © 2008 Wiley-Liss, Inc. [source] Inhibition of Cdk6 expression through p38 MAP kinase is involved in differentiation of mouse prechondrocyte ATDC5JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2005Toru Moro Because a temporal arrest in the G1-phase of the cell cycle is a prerequisite for cell differentiation, this study investigated the involvement of cell cycle factors in the differentiation of cultured mouse prechondrocyte cell line ATDC5. Among the G1 cell cycle factors examined, both protein and mRNA levels of cyclin-dependent kinase (Cdk6) were downregulated during the culture in a differentiation medium. The protein degradation of Cdk6 was not involved in this downregulation because proteasome inhibitors did not reverse the protein level. When inhibitors of p38 MAPK, ERK-1/2, and PI3K/Akt were added to the culture, only a p38 MAPK inhibitor SB203580 blocked the decrease in the Cdk6 protein level by the differentiation medium, indicating that the Cdk6 inhibition was mediated by p38 MAPK pathway. In fact, p38 MAPK was confirmed to be phosphorylated during differentiation of ATDC5 cells. Enforced expression of Cdk6 in ATDC5 cells blocked the chondrocyte differentiation and inhibited Sox5 and Sox6 expressions. However, the Cdk6 overexpression did not affect the proliferation or the cell cycle progression, suggesting that the inhibitory effect of Cdk6 on the differentiation was exerted by a mechanism largely independent of its cell cycle regulation. These results indicate that Cdk6 may be a regulator of chondrocyte differentiation and that its p38-mediated downregulation is involved in the efficient differentiation. © 2005 Wiley-Liss, Inc. [source] AUF-1 mediates inhibition by nitric oxide of lipopolysaccharide-induced matrix metalloproteinase-9 expression in cultured astrocytesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2006Wenlan Liu Abstract Neuroinflammatory diseases are associated with increased production of matrix metalloproteinase-9 (MMP-9) and excessive generation of nitric oxide (NO). NO hasbeen reported to have variable effects on MMP-9 gene expression and activation in various cell types. Inthe present study, we investigated the effect of NOon MMP-9 expression in primary cortical astrocytes. Zymography and real-time PCR showed that lipopolysaccharide (LPS) dramatically increased latent MMP-9 gelatinolytic activity and MMP-9 mRNA expression. By using the NO donor DETA NONOate, we observed a dose-dependent inhibition of MMP-9 induction by LPS. Active forms of MMP-9 were not found by zymography after NO treatment. The MEK1/2 inhibitor U0126 completely inhibited LPS-induced MMP-9, which was partially inhibited by the p38 MAPK inhibitor SB203580. NO had no effect on LPS-stimulated ERK1/2 and p38 MAPK activation, suggesting that the inhibitory action of NO occurs downstream of MAPK cascades. Real-time PCR analysis showed that NO accelerated the degradation of MMP-9 mRNA after LPS induction. Western blotting and pull-down assay demonstrated that NO increased AUF-1 expression as well as its specific binding to the MMP-9 gene 3,-untranslated region. Knockdown of AUF-1 with siRNA partially reversed the inhibitory action of NO on LPS-stimulated MMP-9 induction. We conclude that NO does not activate MMP-9 in astrocyte cultures but reduces LPS-induced MMP-9 expression via accelerating MMP-9 mRNA degradation, which is partially mediated by AUF-1. Our results suggest that elevated NO concentrations may suppress MMP-9 and restrict the inflammatory response in neurodegenerative diseases. © 2006 Wiley-Liss, Inc. [source] Induction of apoptosis of RAW 264.7 cells by the cytostatic macrolide apicularen AJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2003JangJa Hong ABSTRACT In RAW 264.7 cells, a mouse leukaemic monocyte cell line, apicularen A decreased cell growth and survival as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in a concentration-dependent manner at 10,1000 nM. Apicularen B, an N -acetyl-glucosamine glycoside of apicularen A, was 10,100-fold less effective than apicularen A. Apicularen A induced a DNA ladder, an increase in the percentage of sub-G1 cells and annexin V-binding cells, and promoted the activation of caspase as revealed by the cleavage of poly(ADP-ribose) polymerase, indicating that apicularen A induced apoptosis in RAW 264.7 cells. In addition, apicularen A phosphorylated p44/42 mitogen-activated protein kinase (MAPK) and p38 MAPK. The p44/42 MAPK inhibitor PD98059 rescued the cells from apicularen-induced decrease in cell growth and survival as determined by the MTT assay, while the p38 MAPK inhibitor SB203580 augmented the effect of apicularen A. This suggested the activation of p44/42 MAPK to be pro-apoptotic and the activation of p38 MAPK anti-apoptotic in apicularen A-treated RAW 264.7 cells. [source] Participation of various kinases in staurosporine-induced apoptosis of RAW 264.7 cellsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2002Kouya Yamaki Staurosporine induced apoptosis of RAW 264.7 cells, a mouse macrophage-like cell line, as determined by DNA fragmentation, the increase of annexin V-stained cells, and the cleavage of poly(ADP- ribose)polymerase (PARP), a substrate of caspase. Analysis of the increase in the percentage of sub-G1 cells revealed that the DNA fragmentation occurred in a time- and concentration-dependent manner at 0.021,2.1 ,m of staurosporine. Staurosporine induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) but suppressed spontaneous phosphorylation of p44/42 MAPK. The p38 MAPK inhibitor SB203580, the MAPK/extracellular signal-regulated kinase kinase inhibitor PD98059 and the phosphatidylinositol 3-kinase (P13K) inhibitor LY294002 potentiated the staurosporine-induced PARP cleavage and DNA fragmentation. The protein kinase A (PKA) inhibitor H-89 potentiated the staurosporine-induced DNA fragmentation without potentiating the PARP cleavage. In contrast, the protein kinase C (PKC) inhibitor Ro-31,8425 suppressed the PARP cleavage and DNA fragmentation. These findings suggested that staurosporine induces apoptosis via the caspase cascade in RAW 264.7 cells. The staurosporine-induced apoptosis is positively regulated by PKC, negatively regulated by p38 MAPK, p44/42 MAPK and P13K via the caspase cascade, and negatively regulated by PKA without regulation of caspase activation. [source] Aurothiomalate inhibits cyclooxygenase 2, matrix metalloproteinase 3, and interleukin-6 expression in chondrocytes by increasing MAPK phosphatase 1 expression and decreasing p38 phosphorylation: MAPK phosphatase 1 as a novel target for antirheumatic drugsARTHRITIS & RHEUMATISM, Issue 6 2010Riina Nieminen Objective Aurothiomalate is a disease-modifying antirheumatic drug that suppresses inflammation and retards cartilage degradation and bone erosion in arthritis. The molecular mechanisms of action of aurothiomalate are not known in detail. MAPK pathways are major signaling pathways in inflammation that regulate the production of many inflammatory and destructive factors in arthritis. The purpose of the present study was to investigate the effects of aurothiomalate on the activity of p38 MAPK and on the expression of MAPK phosphatase 1 (MKP-1), cyclooxygenase 2 (COX-2), matrix metalloproteinase 3 (MMP-3), and interleukin-6 (IL-6) in immortalized murine H4 chondrocytes and in intact human and murine cartilage. Methods Protein expression was examined by Western blotting or by enzyme-linked immunosorbent assay, and messenger RNA (mRNA) expression was examined by real-time reverse transcription,polymerase chain reaction analysis. The mediator role of MKP-1 was investigated by using small interfering RNA (siRNA) methods to down-regulated MKP-1 expression in chondrocytes in culture and by comparing the responses in intact cartilage from MKP-1,deficient and wild-type mice. The effects of aurothiomalate were also confirmed in human rheumatoid cartilage by using tissue samples obtained at the time of total knee replacement surgery. Results Aurothiomalate inhibited IL-1,,induced COX-2 expression and prostaglandin E2 production by destabilizing COX-2 mRNA, as did the p38 MAPK inhibitor SB203580. Interestingly, aurothiomalate also increased the expression of MKP-1 and reduced the IL-1,,induced phosphorylation of p38 MAPK. Knockdown of MKP-1 by siRNA significantly impaired the ability of aurothiomalate to inhibit the phosphorylation of p38 MAPK and the expression of COX-2, MMP-3, and IL-6. Likewise, aurothiomalate reduced COX-2, MMP-3, and IL-6 expression in articular cartilage from patients with rheumatoid arthritis, as well as in articular cartilage from wild-type mice but not from MKP-1,/, mice. Conclusion Our findings indicate a novel mechanism for the antiinflammatory and antierosive actions of aurothiomalate, through increased expression of MKP-1, which leads to reduced activation of p38 MAPK and suppressed expression of COX-2, MMP-3, and IL-6. The results suggest that manipulation of MKP-1 levels is a promising new mechanism to be directed in the search and development of novel antiinflammatory and antierosive compounds that have the good efficacy of gold compounds but not their toxicity. [source] Chitosan Oligosaccharides Inhibit the Expression of Interleukin-6 in Lipopolysaccharide-induced Human Umbilical Vein Endothelial Cells Through p38 and ERK1/2 Protein KinasesBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2010Hong-Tao Liu However, the potential roles of COS in the treatment of vascular inflammations remain unknown. In the present study, we examined the effects of COS on interleukin-6 (IL-6) production in human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS). Induction of HUVECs with LPS (100 ng/ml) increased the mRNA expression and protein secretion of IL-6 (versus the vehicle-treated group, p < 0.01), which were significantly reverted by the pre-treatment with COS (50,200 ,g/ml) for 24 hr before LPS exposure (versus the LPS-treated group, p < 0.05 or 0.01). Signal transduction studies showed that the pre-treatment of HUVECs with COS (50,200 ,g/ml) for 24 hr markedly inhibited the LPS-induced over-expression of phosphorylated p38 mitogen-activated protein kinase (MAPK), phosphorylated ERK1/2 and nuclear factor ,B (NF-,B). Moreover, the LPS-induced NF-,B activation was suppressed by the specific ERK1/2 inhibitor PD98059 (30 ,M) (versus the LPS-treated group, p < 0.01), but not by the specific p38 MAPK inhibitor SB203580 (25 ,M). Additionally, both MAPK inhibitors markedly suppressed LPS-induced IL-6 mRNA expression in HUVECs (versus the LPS-treated group, p < 0.01). In conclusion, our results suggest that COS inhibit LPS-induced up-regulation of IL-6 in HUVECs, and this can be regulated by at least two parallel signalling pathways: one via p38 MAPK pathway independent of NF-,B activation and one via ERK1/2 pathway dependent on NF-,B activation. [source] | |||||||||||||