Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003864 (arthritis)
 69,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently, glycogen synthase kinase-3 (GSK-3) has being identified as an ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and plays an important role in the pathophysiology of a number of diseases. The aim of this study was to investigate the effects of GSK-3beta inhibition on the degree of arthritis caused by type II collagen (CII) in the mouse (collagen-induced arthritis; CIA). Mice developed erosive hind paw arthritis when immunized with CII in an emulsion in complete Freund's adjuvant (CFA). The incidence of CIA was 100% by day 28 in the CII-challenged mice and the severity of CIA progressed over a 35-day period with radiographic evaluation revealing focal resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint margins. Treatment of mice with the GSK-3beta inhibitor TDZD-8 (1 mg/kg/day i.p.) starting at the onset of arthritis (day 25) ameliorated the clinical signs at days 26-35 and improved histological status in the joint and paw. Immunohistochemical analysis for nitrotyrosine, poly(ADP-ribose) (PAR), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) revealed a positive staining in inflamed joints from mice subjected to CIA. The degree of staining for nitrotyrosine, PAR, iNOS, and COX-2 was significantly reduced in CII-challenged mice treated with the GSK-3beta inhibitor. Plasma levels of tumor necrosis factor (TNF)-alpha and the joint tissue levels of macrophage inflammatory protein (MIP)-1alpha and MIP-2 were also significantly reduced by GSK-3beta inhibition. These data demonstrate that GSK-3beta inhibition exerts an anti-inflammatory effect during chronic inflammation and is able to ameliorate the tissue damage associated with CIA.
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PMID:Glycogen synthase kinase-3beta inhibition attenuates the degree of arthritis caused by type II collagen in the mouse. 1663 8

One of the central functions of cyclin-dependent kinase inhibitors, such as p21, p27, or p16, is to prevent entry into the cell cycle. However, the question remains as to whether they have other functions in the cell. We previously demonstrated that overexpression of p21 in fibroblasts isolated from patients with rheumatoid arthritis decreases the production of pro-inflammatory molecules. Overexpression of p21 has been also shown to reduce the development of experimental arthritis in mice and rats. To explore the role of endogenous p21 in the development of arthritis, we induced arthritis in p21(-/-) mice using the K/BxN serum transfer model of arthritis. Mice deficient in p21 were more resistant to serum transfer-induced arthritis (K/BxN) than wild-type (wt) control mice. Fewer macrophages were detected in p21(-/-) as compared to wt joints following transfer of K/BxN serum. Chemotaxis assays of bone marrow-derived macrophages from p21(-/-) and wt mice revealed no difference in migration. However, there was a substantial decrease in inflammatory monocytes circulating in peripheral blood and in monocyte precursors in bone marrow of p21(-/-) mice as compared to wt mice. Adoptive transfer of wt bone marrow-derived macrophages into p21(-/-) mice restored the sensitivity to serum transfer-induced arthritis. These data suggest a novel role for p21 in regulating the development and/or differentiation of monocytic populations that are crucial for the induction of inflammatory arthritis.
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PMID:p21Cip1 is required for the development of monocytes and their response to serum transfer-induced arthritis. 1665 20

We previously established a role for the second messenger ceramide in protein kinase R (PKR)-mediated articular cartilage degradation. Ceramide is known to play a dual role in collagen gene regulation, with the effect of ceramide on collagen promoter activity being dependent on its concentration. Treatment of cells with low doses of sphingomyelinase produces small increases in endogenous ceramide. We investigated whether ceramide influences articular chondrocyte matrix homeostasis and, if so, the role of PKR in this process. Bovine articular chondrocytes were stimulated for 7 days with sphingomyelinase to increase endogenous levels of ceramide. To inhibit PKR, 2-aminopurine was added to duplicate cultures. De novo sulphated glycosaminoglycan and collagen synthesis were measured by adding [35S]-sulphate and [3H]-proline to the media, respectively. Chondrocyte phenotype was investigated using RT-PCR and Western blot analysis. Over 7 days, sphingomyelinase increased the release of newly synthesized sulphated glycosaminoglycan and collagen into the media, whereas inhibition of PKR in sphingomyelinase-treated cells reduced the level of newly synthesized sulphated glycosaminoglycan and collagen. Sphingomyelinase treated chondrocytes expressed col2a1 mRNA, which is indicative of a normal chondrocyte phenotype; however, a significant reduction in type II collagen protein was detected. Therefore, small increments in endogenous ceramide in chondrocytes appear to push the homeostatic balance toward extracellular matrix synthesis but at the expense of the chondrocytic phenotype, which was, in part, mediated by PKR.
Arthritis Res Ther 2006
PMID:Exogenous sphingomyelinase increases collagen and sulphated glycosaminoglycan production by primary articular chondrocytes: an in vitro study. 1669 62

The stress-activated protein kinase (SAPK) and mitogen-activated protein kinase (MAPK) sub-families are crucial to environmental stress responses and responses to growth factors that cause transcriptional activation of genes required for cell proliferation, differentiation and programmed cell death. Small molecular compounds with specific structure/activity characteristics have been developed that competitively block SAPK/MAPK binding to ATP. Chemically modified compounds based on ATP binding pocket characteristics have improved selectivity and specificity for SAPK/MAPK isoforms. In addition, site-specific mutagenesis of MAPKs has helped identify the MAPK structures required for binding recognition and selectivity of these inhibitors. A group of extracellular-signal regulated protein kinase (ERK) inhibitors has been constructed based almost exclusively on their ability to inhibit the ERK activation cascade. Inhibitors have been employed in vitro to identify protein targets and mechanism of action of SAPKs/MAPKs. The efficacy of SAPK/MAPK inhibitors in animal models of inflammation, arthritis, heart failure, cancer and neurological degeneration has provided the impetus for using them in human studies of inflammation and in clinical trials.
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PMID:Small molecular weight inhibitors of stress-activated and mitogen-activated protein kinases. 1678 80

Much attention has focused on the development of protein kinases as drug targets to treat a variety of human diseases including diabetes, cancer, hypertension and arthritis. To date, Gleevec is one example of a drug targeting protein that has successfully treated human cancer. Several other protein kinase inhibitors are in clinical development. However, protein kinases are in fact part of a larger collection of some 2000 distinct proteins expressed by the genome that like the protein kinases also bind purines (the purinome), either to be utilized as substrates or as co-factors in the form of NAD, NADP and co-enzyme A. The solution structures of many representative gene family members within the purinome show these proteins bind purines in a similar orientations to that observed in all protein kinases. Several non-protein kinase purine utilizing proteins are established drug targets such as HMG CoA reductase, dihydrofolate reductase, phosphodiesterase and HSP90. Searches of OMIM identifies many purine utilizing enzymes that are associated with inborn errors in metabolism. Inhibition of any one of which by a drug could lead to an undesirable side effect. The purinome is therefore somewhat of a drug discovery mixed blessing. It is a rich source of therapeutic targets, but also contains a large collection of diverse proteins whose inhibition could result in an adverse outcome. Drug discovery within the purinome should therefore encompass strategies that enable broad assessment of selectivity across the entire purinome at the earliest stages of the discovery process. In this article we review the purinome within the context of drug discovery and discuss approaches for avoiding off target binding during the discovery/lead optimization process with particular emphasis on use of proteome mining technology.
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PMID:The purinome, a complex mix of drug and toxicity targets. 1684 50

Apoptosis is essential for clearance of potentially injurious inflammatory cells and subsequent efficient resolution of inflammation. Here we report that human neutrophils contain functionally active cyclin-dependent kinases (CDKs), and that structurally diverse CDK inhibitors induce caspase-dependent apoptosis and override powerful anti-apoptosis signals from survival factors such as granulocyte-macrophage colony-stimulating factor (GM-CSF). We show that the CDK inhibitor R-roscovitine (Seliciclib or CYC202) markedly enhances resolution of established neutrophil-dependent inflammation in carrageenan-elicited acute pleurisy, bleomycin-induced lung injury, and passively induced arthritis in mice. In the pleurisy model, the caspase inhibitor zVAD-fmk prevents R-roscovitine-enhanced resolution of inflammation, indicating that this CDK inhibitor augments inflammatory cell apoptosis. We also provide evidence that R-roscovitine promotes apoptosis by reducing concentrations of the anti-apoptotic protein Mcl-1. Thus, CDK inhibitors enhance the resolution of established inflammation by promoting apoptosis of inflammatory cells, thereby demonstrating a hitherto unrecognized potential for the treatment of inflammatory disorders.
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PMID:Cyclin-dependent kinase inhibitors enhance the resolution of inflammation by promoting inflammatory cell apoptosis. 1695 85

Extracellular signal-regulated kinase (ERK), a serine/threonine protein kinase of the mitogen-activated protein kinase superfamily, is activated by various stimuli in inflammatory cells. We recently described FR180204 (5-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-1H-pyrazolo[3,4-c]pyridazin-3-amine), a novel selective ERK inhibitor. In this paper, we investigated the effect of FR180204 on collagen-induced arthritis (CIA) in DBA/1 mice, an animal model of rheumatoid arthritis (RA) mediated by type II collagen (CII)-reactive T cells and anti-CII antibodies. Preventive administration of FR180204 (100 mg/kg, i.p., b.i.d.) significantly ameliorated the clinical arthritis and body weight loss occurring in the CIA mice. Further, FR180204-treated mice showed a significant decrease in plasma anti-CII antibody levels (62%). FR180204 also attenuated delayed-type hypersensitivity in CII-immunized DBA/1 mice, an inflammatory response elicited by CII-reactive T cells, in a dose-dependent manner (52 and 62% inhibition at 32 and 100 mg/kg, respectively). Moreover, FR180204 inhibited in vitro CII-induced proliferation of lymph node cells prepared from CII-immunized mice, in which CII-specific T cells are known to undergo specific proliferation. In conclusion, our results suggest that ERK regulates both the cell-mediated and humoral immune responses in the development of CIA. ERK inhibitors may be useful as therapeutic reagents for the treatment of RA.
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PMID:FR180204, a novel and selective inhibitor of extracellular signal-regulated kinase, ameliorates collagen-induced arthritis in mice. 1712 65

The p38 protein kinase is a serine-threonine mitogen activated protein kinase, which plays an important role in inflammation and arthritis. A combined study of 3D-QSAR and molecular docking has been undertaken to explore the structural insights of pyrazolyl urea p38 kinase inhibitors. The 3D-QSAR studies involved comparative molecular field analysis (CoMFA) and comparative molecular similarity indices (CoMSIA). The best CoMFA model was derived from the atom fit alignment with a cross-validated r (2 )(q (2)) value of 0.516 and conventional r (2) of 0.950, while the best CoMSIA model yielded a q (2) of 0.455 and r (2) of 0.979 (39 molecules in training set, 9 molecules in test set). The CoMFA and CoMSIA contour maps generated from these models provided inklings about the influence of interactive molecular fields in the space on the activity. GOLD, Sybyl (FlexX) and AutoDock docking protocols were exercised to explore the protein-inhibitor interactions. The integration of 3D-QSAR and molecular docking has proffered essential structural features of pyrazolyl urea inhibitors and also strategies to design new potent analogues with enhanced activity.
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PMID:Strategies to design pyrazolyl urea derivatives for p38 kinase inhibition: a molecular modeling study. 1720 64

We have recently demonstrated that the rheumatoid arthritis (RA) shared epitope (SE) acts as a ligand that triggers nitric oxide (NO) signaling in opposite cells. Given the known pro-oxidative effect of NO and the proposed role of oxidative stress in the pathogenesis of RA, this study explores whether SE-triggered signaling can increase cellular oxidative stress. cAMP levels, adenylyl cyclase activity, and protein kinase A activity were measured using commercial kits. Generation of reactive oxygen species (ROS) was quantified using the fluorochrome dichlorofluorescein diacetate. Oxidative DNA damage was quantified using the single-cell electrophoresis technique. Here, we report that cells exposed to cell surface SE-positive HLA-DR (human leukocyte antigen-DR) molecules, to cell-free recombinant proteins genetically engineered to express the SE motif, or to SE-positive synthetic peptide showed diminished cAMP-dependent signaling, increased ROS levels, and higher vulnerability to oxidative DNA damage. Introduction of single amino acid substitutions into SE-positive peptides revealed a consensus five-amino acid sequence motif of Q/R-K/R-X-X-A that is necessary and sufficient for SE-triggered signaling. The pro-oxidative effect of the SE could be reversed by inhibiting NO production. We conclude that the SE acts as a signaling ligand that activates an NO-mediated pro-oxidative pathway. The potential contribution of this signaling aberration to RA pathogenesis is discussed.
Arthritis Res Ther 2007
PMID:The rheumatoid arthritis shared epitope increases cellular susceptibility to oxidative stress by antagonizing an adenosine-mediated anti-oxidative pathway. 1725 42

Peripheral corticotropin-releasing hormone (CRH) is an important regulator of localized inflammatory responses. The aim of this study is to define the pathological signaling pathways in which peripheral CRH receptor-mediated responses reside. We report that PECAM-1-expressing synovial membrane endothelial cells are the principal source of CRH receptor subtype 1alpha in chronically inflamed synovial tissue (ST). Analysis of ST from an early arthritis patient cohort (n = 9) established that expression of CRH-R1alpha significantly (P < 0.03) colocalized with PECAM-1 and E-selectin expression in vivo. Freshly excised ST explants released a mediator(s) that acts to promote CRH-R1alpha mRNA to levels present in inflamed human synovium (n = 8). We tested the ability of conditioned medium and individual inflammatory mediators to modulate CRH-R1alpha expression. Histamine selectively induced the expression of CRH-R1alpha, and these effects were mediated through the histamine receptor type 1. Ectopic expression of CRH-R1alpha in normal human endothelial and synoviocyte cells resulted in the induction of the orphan receptor NR4A2 through the reconstitution of cAMP/protein kinase A/cAMP response element-binding protein signaling and identified a role for CRH in modulating nuclear factor kappaB transcriptional activity. CRH enhanced the expression of nitric-oxide synthase (NOS III) to promote NO production from CRH-R1alpha-expressing cells. These data establish a role for CRH receptor-mediated responses in regulating vascular changes associated with chronic synovitis.
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PMID:A role for type 1alpha corticotropin-releasing hormone receptors in mediating local changes in chronically inflamed tissue. 1732 94


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