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ID PMID Title PublicationDate abstract
16519819 Analysis of polymorphisms in 16 genes in type 1 diabetes that have been associated with ot 2006 Mar 6 BACKGROUND: The identification of the HLA class II, insulin (INS), CTLA-4 and PTPN22 genes as determinants of type 1 diabetes (T1D) susceptibility indicates that fine tuning of the immune system is centrally involved in disease development. Some genes have been shown to affect several immune-mediated diseases. Therefore, we tested the hypothesis that alleles of susceptibility genes previously associated with other immune-mediated diseases might perturb immune homeostasis, and hence also associate with predisposition to T1D. METHODS: We resequenced and genotyped tag single nucleotide polymorphisms (SNPs) from two genes, CRP and FCER1B, and genotyped 27 disease-associated polymorphisms from thirteen gene regions, namely FCRL3, CFH, SLC9A3R1, PADI4, RUNX1, SPINK5, IL1RN, IL1RA, CARD15, IBD5-locus (including SLC22A4), LAG3, ADAM33 and NFKB1. These genes have been associated previously with susceptibility to a range of immune-mediated diseases including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Graves' disease (GD), psoriasis, psoriatic arthritis (PA), atopy, asthma, Crohn disease and multiple sclerosis (MS). Our T1D collections are divided into three sample subsets, consisting of set 1 families (up to 754 families), set 2 families (up to 743 families), and a case-control collection (ranging from 1,500 to 4,400 cases and 1,500 to 4,600 controls). Each SNP was genotyped in one or more of these subsets. Our study typically had approximately 80% statistical power for a minor allele frequency (MAF) >5% and odds ratios (OR) of 1.5 with the type 1 error rate, alpha = 0.05. RESULTS: We found no evidence of association with T1D at most of the loci studied 0.02

16846524 Autoantibodies against the replication protein A complex in systemic lupus erythematosus a 2006 Replication protein A (RPA), a heterotrimer with subunits of molecular masses 70, 32, and 14 kDa, is a single-stranded-DNA-binding factor involved in DNA replication, repair, and recombination. There have been only three reported cases of anti-RPA in systemic lupus erythematosus (SLE) and Sjögren syndrome (SjS). This study sought to clarify the clinical significance of autoantibodies against RPA. Sera from 1,119 patients enrolled during the period 2000 to 2005 were screened by immunoprecipitation (IP) of 35S-labeled K562 cell extract. Antigen-capture ELISA with anti-RPA32 mAb, immunofluorescent antinuclear antibodies (ANA) and western blot analysis with purified RPA were also performed. Our results show that nine sera immunoprecipitated the RPA70-RPA32-RPA14 complex and all were strongly positive by ELISA (titers 1:62,500 to 1:312,500). No additional sera were positive by ELISA and subsequently confirmed by IP or western blotting. All sera showed fine speckled/homogeneous nuclear staining. Anti-RPA was found in 1.4% (4/276) of SLE and 2.5% (1/40) of SjS sera, but not in rheumatoid arthritis (0/35), systemic sclerosis (0/47), or polymyositis/dermatomyositis (0/43). Eight of nine patients were female and there was no racial predilection. Other positive patients had interstitial lung disease, autoimmune thyroiditis/hepatitis C virus/pernicious anemia, or an unknown diagnosis. Autoantibody specificities found in up to 40% of SLE and other diseases, such as anti-nRNP, anti-Sm, anti-Ro, and anti-La, were unusual in anti-RPA-positive sera. Only one of nine had anti-Ro, and zero of nine had anti-nRNP, anti-Sm, anti-La, or anti-ribosomal P antibodies. In summary, high titers of anti-RPA antibodies were found in nine patients (1.4% of SLE and other diseases). Other autoantibodies found in SLE were rare in this subset, suggesting that patients with anti-RPA may form a unique clinical and immunological subset.
16200621 Association between lack of angiogenic response in muscle tissue and high expression of an 2005 Oct OBJECTIVE: To investigate the relationship between the vasculopathy of juvenile dermatomyositis (juvenile DM) and the balance between the angiostatic ELR- and angiogenic ELR+ CXC chemokines in the muscle of patients with the disease. METHODS: The expression of 3 ELR- CXC chemokines (interferon-inducible protein 10 [IP-10], monokine induced by interferon-gamma, and interferon-inducible T cell alpha-chemoattractant) and 2 ELR+ CXC chemokines was quantitated in muscle biopsy samples from 7 patients with juvenile DM and 7 healthy children, by real-time polymerase chain reaction. The findings were correlated with various histopathologic features, with particular emphasis on the degree of vasculopathy. Synovial biopsy specimens from patients with juvenile rheumatoid arthritis (JRA) were used for additional comparison. RESULTS: The angiostatic ELR- chemokines were expressed at high levels, while the angiogenic ELR+ chemokines were barely detectable, in most juvenile DM samples. This contrasted sharply with the findings in both normal muscle biopsy specimens and JRA synovial tissue specimens. The expression of the ELR- chemokines in juvenile DM samples correlated with the intensity of mononuclear cell infiltration. Furthermore, the juvenile DM samples with the highest degree of capillary loss had the highest levels of ELR- CXC chemokines. The presence of IP-10 in juvenile DM muscle specimens was confirmed by immunohistochemistry analysis. In addition, immunohistochemical staining of muscle tissue revealed that CXCR3, a receptor utilized by ELR- CXC chemokines, was expressed in vascular endothelial cells. CONCLUSION: Increased expression of the interferon-induced angiostatic ELR- CXC chemokines is a feature of juvenile DM that parallels the degree of vasculopathy in patients with the disease. Collectively, these findings are consistent with a model in which a subset of inflammatory cells secrete angiostatic ligands, which then contribute to a local atrophying effect on the muscle's vasculature via a receptor-mediated process.
17077019 [The abnormality of FcgammaRIIB1-mediated signaling and the hyperactivity of B cells from 2006 Nov AIM: To evaluate the effect of FcgammaRIIB(1) (CD32) representative self-inhibitory adjustive mechanism of B cells on pathogenesis of systemic lupus erythematosus (SLE) by observing the expression characteristic and functional state of molecules on the surface of B cells from SLE patients. METHODS: The peripheral blood mononuclear cells (PBMC) were prepared by density gradient centrifugation, and the B cells were isolated from PBMC by magnetic activated cell sorting (MACS). The fluxes of intracytoplasmic calcium ([Ca(2+)](i)) of B cells activated by different activators were measured by fluorescence spectrophotometric method. The IgG production by B cells cultured with activators was assayed by ELISA. The expression levels of CD32, CD19, and IgM on the surface of B cells were measured by flow cytometry. RESULTS: (1)After B cells were stimulated with goat anti-human mu chain F(ab')(2) fragments and whole IgG respectively, the ratio of [Ca(2+)](i) response by F(ab')(2) fragments to whole IgG was significantly lower in SLE B cells compared to rheumatoid arthritis (RA)(P<0.05) or normal (P<0.01) B cells. (2)The ratio of total IgG production by B cells cultured with staphylococcal protein A (SPA) to SPA plus IgG anti-mu chain was significantly lower in SLE patients compared to RA patients or normal individuals (P<0.05). (3)There was no obvious difference in the expression of CD19, CD32, and IgM on the surface of B cells from SLE, RA patients and normal individuals (P>0.05). CONCLUSION: The inhibitory signaling abnormality of CD32 possibly contributes to the mechanism of hyperactivity of human SLE B cells.
16984135 Delivery of the p38 MAPkinase inhibitor SB202190 to angiogenic endothelial cells: developm 2006 Sep Endothelial cells play an important role in inflammatory disorders, as they control the recruitment of leukocytes into inflamed tissue and the formation of new blood vessels. Activation of p38MAP kinase results in the production of proinflammatory cytokines and the expression of adhesion molecules. P38MAP kinase inhibitors are therefore considered important candidates for the treatment of inflammatory disorders. In the present study, we propose a novel strategy to counteract these processes by delivery of the p38MAP kinase inhibitor SB202190 into angiogenic endothelial cells. A drug-targeting conjugate was developed by conjugation of SB202190 to human serum albumin (HSA) using a novel platinum-based linker. Specificity for angiogenic endothelial cells was introduced by conjugation of cyclic RGD-peptides via bifunctional polyethylene glycol linkers. The final products contained an average of nine SB202190 and six RGDPEG groups per albumin. The platinum-based linker displayed high stability in buffers and culture medium, but released SB202190 slowly upon competition with sulfur-containing ligands like glutathione. RGDPEG-SB-HSA bound to alpha(v3)-integrin expressing endothelial cells (human umbilical cord vein endothelial cells) with low nanomolar affinity and was subsequently internalized. When HUVEC were treated with TNF to induce inflammatory events, pretreatment with RGDPEG-SB-HSA partially inhibited proinflammatory gene expression (IL-8, E-selectin; 30% inhibition) and secretion of cytokines (IL-8, 34% inhibition). We conclude that the developed RGDPEG-SB-HSA conjugates provide a novel means to counteract inflammation disorders such as rheumatoid arthritis.
16918914 Stochastic search gene suggestion: a Bayesian hierarchical model for gene mapping. 2006 Jun Mapping the genes for a complex disease, such as diabetes or rheumatoid arthritis (RA), involves finding multiple genetic loci that may contribute to the onset of the disease. Pairwise testing of the loci leads to the problem of multiple testing. Looking at haplotypes, or linear sets of loci, avoids multiple tests but results in a contingency table with sparse counts, especially when using marker loci with multiple alleles. We propose a hierarchical Bayesian model for case-parent triad data that uses a conditional logistic regression likelihood to model the probability of transmission to a diseased child. We define hierarchical prior distributions on the allele main effects to model the genetic dependencies present in the human leukocyte antigen (HLA) region of chromosome 6. First, we add a hierarchical level for model selection that accounts for both locus and allele selection. This allows us to cast the problem of identifying genetic loci relevant to the disease into a problem of Bayesian variable selection. Second, we attempt to include linkage disequilibrium as a covariance structure in the prior for model coefficients. We evaluate the performance of the procedure with some simulated examples and then apply our procedure to identifying genetic markers in the HLA region that influence risk for RA. Our software is available on the website http://www.epigenetic.org/Linkage/ssgs-public/.
16872241 Safety of etanercept in psoriasis: a critical review. 2006 Conventional systemic treatments for patients with psoriasis are associated with multiple adverse effects that require continuous monitoring. The introduction of new biological agents such as etanercept, a fully human fusion protein, has permitted individualisation of patients' treatment according to disease stage. The drug is a competitive inhibitor of tumour necrosis factor-alpha (TNFalpha) that prevents interaction between this cytokine and its cell surface receptors. Etanercept also modulates the activity of other inflammatory cytokines and does not induce complement-mediated cell lysis in vitro. The main source of information regarding etanercept safety comes from studies in patients with rheumatoid arthritis. The most common adverse effect during drug administration is mild injection site reactions. There is no increase in the overall incidence of infections compared with placebo, although there have been several reports of infections caused by intracellular organisms (Mycobacterium tuberculosis, Listeria monocytogenes, and Mycobacterium avium intracellulare). Therefore, combination of this drug with corticosteroids must be carefully monitored and should be avoided in patients with established sepsis. There are no data showing that treatment with etanercept results in an increase in the occurrence of malignant neoplasms. However, caution is recommended in use of etanercept in patients with a current or past history of demyelinating disease. Etanercept must be used with extreme caution in patients with heart failure because of several reports indicating a worsening or de novo occurrence of congestive heart failure while receiving the drug. Monitoring of autoantibodies is not currently considered necessary as they do not predict response, toxicity or autoimmune events. The presence of non-neutralising antibodies to the TNF receptor fragment or other protein components of etanercept has not been related to a decrease in drug response or adverse reactions. Etanercept does not generally modify the course of inflammatory bowel disease. When combined with other systemic therapies for psoriasis, current data do not show an increase in adverse events. In patients with hepatitis C viral infection, etanercept does not increase transaminase levels or viral load and in some instances has allowed the concomitant use of interferon which had previously been discontinued because of a worsening of psoriasis. Etanercept is rated as a US FDA category B drug in pregnancy. However, its use is not recommended in pregnant women unless the benefit-risk ratio greatly favours its use. Etanercept is not recommended for use in lactating women. Etanercept represents a relevant treatment for psoriasis, efficacious over many weeks and safe but special care should be taken to avoid the potential risks.
16701959 Solar cycles and their relationship to human disease and adaptability. 2006 In this paper, we show that 11-year solar cycle peaks predispose humans to disease, but also endow creativity and adaptability. We give several examples of diseases that are modulated by light and present evidence for an effect of intensity and variation in sunlight, primarily ultraviolet radiation (UVR), on the human genome. The birth dates of nearly 237,000 unique clients in the Maine Medicaid database collected from 1995 to 2004, inclusive, were related to solar cycle irradiance for the past seventy-one years, encompassing seven solar cycles. The sample was divided into four general categories of disease: mental/behavioral illnesses; metabolic diseases; autoimmune diseases; neoplasms. The birth months for those clients born in any given year were arranged in the form of a winter/summer ratio in order to more clearly appreciate the seasonality inherent in each disease category. Solar cycles were separated into chaotic (approximately three times as irradiant) or non-chaotic according to the Gutenberg-Richter power law and the uncertainty inherent in predicting solar storms. The results show that radiation peaks in solar cycles and particularly in chaotic solar cycles (CSCs) are associated with a higher incidence of mental disorders, suggesting the sensitivity of ectodermal embryonic tissues to UVR. Autoimmune diseases have intermediate sensitivity, while the neoplasms in the study, primarily of endoderm, appear suppressed by peak UVR intensity. The ratio of the number of clients born in CSC cycles to non-CSC cycles was highest for the more genetic mental diseases, like schizophrenia and bipolar disorder, but as that ratio decreased, the clients with diseases like multiple sclerosis and rheumatoid arthritis showed more environmental features manifested as a greater winter/summer birth month ratio that was significantly different than that of the average client in the whole data set. The paper presents evidence that latitude, e.g., variation in light, is an added stress to the immune system (especially at 53-54 degrees N. latitude) that is involved in nearly all human disease. We hypothesize that introns, the presumptive engenderers of gene control, modulate the effects of UVR, particularly for the neoplasms studied. We conclude that intermittent and largely unpredictable peak solar cycle radiation has been the fundamental engine of evolution, forcing organisms to adapt to mutagenic UVR and producing enough damage to instigate genetic variation. Probably a chance genetic mutation over 80,000 years ago produced a human brain capable of abstract thought and consciousness. The slight genetic instability that favored an adaptable, creative brain also produced other somatic variations that present phenotypically as disease, but largely expressed after natural selection (reproduction) and associated with the inexorable entropy of aging.
16652442 B cell targeted therapies in autoimmune diseases. 2006 May In addition to rheumatoid arthritis (RA), B cells are likely to play a significant role in the development of other autoimmune rheumatic diseases, such as systemic lupus erythematosus (SLE), myositis, and vasculitis. Small-vessel vasculitis subtypes may be immune complex-mediated (cryoglobulinemia) or antineutrophil cytoplasmic antibody (ANCA)-associated; ANCA may be involved in the pathogenesis of vasculitis. In SLE, both antibody-associated and antibody-independent processes are almost certainly involved. B cell activity and autoantibody production are increased, while patients often have reduced peripheral B cells and abnormal B cell profiles. B lymphocyte stimulator (BLyS) protein regulates B cell activation and differentiation. For these reasons, B cells and the molecules that activate them are potential therapeutic targets in these diseases. Recent clinical trial data from small studies of rituximab (RTX) in SLE suggest that treatment improved clinical variables and measures of disease activity in patients, including those with central nervous system SLE. With retreatment, patients whose B cells were successfully depleted continued to show improvement in clinical and laboratory variables. Preliminary data suggest that treatment with RTX may be effective in ANCA-associated vasculitis. In addition a recent study showed significant benefit with myositis. Although these studies contain small cohorts of patients, they demonstrate that B cell-modulating therapies show promise in treatment of a variety of autoimmune diseases.
16574371 Anti-inflammatory effect of Poncirus trifoliata fruit through inhibition of NF-kappaB acti 2006 Oct Mast cell-mediated allergic inflammation is involved in many diseases such as asthma, sinusitis, and rheumatoid arthritis. Mast cells induce synthesis and production of pro-inflammatory cytokines including tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 with immune regulatory properties. We investigated the effect of the fruits of Poncirus trifoliata (L.) Raf (Rutaceae) (FPT) on expression of pro-inflammatory cytokines by activated human mast cell line, HMC-1. FPT dose dependently decreased the gene expression and production of TNF-alpha and IL-6 on phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-stimulated HMC-1 cells. In addition, FPT attenuated PMA and A23187-induced activation of NF-kappaB indicated by inhibition of degradation of I kappa B alpha, nuclear translocation of NF-kappaB, NF-kappaB/DNA binding, and NF-kappaB-dependent gene reporter assay. Our in vitro studies provide evidence that FPT might contribute to the treatment of mast cell-derived allergic inflammatory diseases.
16536903 Suppression of matrix metalloproteinase production from synovial fibroblasts by meloxicam 2006 Mar The aim of this study was to evaluate the influence of meloxicam on the production of both matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) from human synovial fibroblasts by TNF-alpha stimulation in-vitro. Synovial fibroblasts (2 x 10(4) cells/mL) derived from patients with osteoarthritis were stimulated with 20.0 ng mL(-1) TNF-alpha in the presence of various concentrations of meloxicam. After 24 h, the culture supernatants were obtained and assayed for MMP-1, MMP-2, MMP-3, MMP-13, TIMP-1 and TIMP-2 by ELISA. mRNA expression for MMPs and TIMPs in 4-h-cultured cells were examined by real-time polymerase chain reaction. Transcriptional factor (NF-kappaB and AP-1) activation in 2-h-cultured cells was also examined by ELISA. Meloxicam could suppress MMP production in a dose-dependent manner. The minimum concentration of the agent that showed significant suppression was 0.6 x 10(-6) M for MMP-1, MMP-2 and MMP-3, and 1.3 x 10(-6) M for MMP-13. The ability of synovial fibroblasts to produce TIMPs was also suppressed by meloxicam as in the case of MMP production. Addition of meloxicam into synovial fibroblast cultures inhibited dose-dependently mRNA expression for MMPs and TIMPs, which were increased by TNF-alpha stimulation, through the suppression of NF-kappaB and AP-1 activation. The suppressive effect of meloxicam on the production of MMPs and TIMPs may partly be involved in attenuation of the clinical conditions of osteoarthritis and rheumatoid arthritis.
16451200 Inhibitory effects on HLA-DR1-specific T-cell activation by influenza virus haemagglutinin 2006 Jan Collagen (CII) 263-272 peptide, an autoantigen in rheumatoid arthritis, is a specific human leukocyte antigen (HLA)-DR1/4-binding peptide recognized by T-cell receptors (TCR). The affinity of influenza virus haemagglutinin (HA) 306-318 peptide for the antigen-binding groove of HLA-DR1/4 molecules is higher than that of CII263-272. The HLA-DR1/4-binding residues of HA306-318 are located in the region 308-317. Altered HA308-317 peptides with substitutions of TCR-contact residues may inhibit HLA-DR1/4-specific T-cell activation by blocking the antigen-binding site of HLA-DR1/4 molecules. To evaluate the role of altered HA308-317 peptides in HLA-DR1-restricted T-cell activation, we synthesized three altered HA308-317 peptides. The specific binding of altered HA308-317 peptides to HLA-DR1 molecules was examined using flow cytometry. Effects of altered HA308-317 peptides on HLA-DR1-specific T-cell hybridoma were studied by measuring T-cell proliferation and surface expression of CD69 or CD25. The results showed that altered HA308-317 peptides were able to bind to HLA-DR1 molecules and competed with CII263-272 or wildtype HA308-317 peptide. Compared with wildtype CII263-272 or HA308-317, altered HA308-317 peptides did not stimulate significant T-cell proliferation and CD69 or CD25 expression. Furthermore, the altered HA308-317 peptides inhibited HLA-DR1-specific T-cell activation induced by CII263-272 or wildtype HA308-317 peptide, which may suggest an effective therapeutic strategy in inhibition of HLA-DR1-specific T-cell responses in autoimmunity.
16234240 Inflammatory cytokines induce production of CHI3L1 by articular chondrocytes. 2005 Dec 16 Elevated levels of CHI3L1 (chitinase-3-like protein 1) are associated with disorders exhibiting increased connective tissue turnover, such as rheumatoid arthritis, osteoarthritis, scleroderma, and cirrhosis of the liver. This secreted protein is not synthesized in young healthy cartilage, but is produced in cartilage from old donors or patients with osteoarthritis. The molecular processes governing the induction of CHI3L1 are currently unknown. To elucidate the molecular events involved in CHI3L1 synthesis, we investigated two models of articular chondrocytes: neonatal rat chondrocytes, which do not express CHI3L1, and human chondrocytes, which express CHI3L1 constitutively. In neonatal rat chondrocytes, the inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 potently induced steady-state levels of CHI3L1 mRNA and protein secretion. Treatment of chondrocytes with TNF-alpha for as little as 1 h was sufficient for sustained induction up to 72 h afterward. Using inhibitors selective for the major signaling pathways implicated in mediating the effects of TNF-alpha and interleukin-1, only inhibition of NF-kappaB activation was effective in curtailing cytokine-induced expression, including after removal of the cytokine, indicating that induction and continued production of CHI3L1 are controlled mainly by this transcription factor. Inhibition of NF-kappaB signaling also abolished constitutive expression by human chondrocytes. Thus, induction and continued secretion of CHI3L1 in chondrocytes require sustained activation of NF-kappaB. Selective induction of CHI3L1 by cytokines acting through NF-kappaB coupled with the known restriction of the catabolic responses by CHI3L1 in response to these inflammatory cytokines represents a key regulatory feedback process in controlling connective tissue turnover.
16213155 Contribution of the familial and genetic factors on monocyte chemoattractant protein-1 var 2005 Oct 21 Monocyte chemoattractant protein-1 (MCP-1) is a chemokine whose circulating levels have been detected in the lesions of several diseases such as pulmonary fibrosis, rheumatoid arthritis and atherosclerosis. However, the factors involved in the regulation of its production remain largely unknown. The main aim of the present paper was to ascertain the contribution of the familial/genetic factors on the production of MCP-1 in apparently healthy individuals. We also tested the possible relationships between the plasma levels of MCP-1 and other cytokines involved in bone metabolism (receptor activator NF-kB ligand (RANKL), osteoprotegerin (OPG), interleukin-6, macrophage-colony stimulating factor, tumor necrosis factor-alpha). Using ELISA assays the cytokine levels were measured in 570 apparently healthy individuals belonging to ethnically homogeneous Caucasian families. We found that MCP-1 levels were significantly (P<0.01) correlated with RANKL (in both sexes) and with OPG only in women. The study showed that adjusted for potential covariates, 72% of the MCP-1 variance, was attributable to familial effects. About 49% was due to potential genetic factors and the rest was explained by common environmental sources shared by spouses within each family. In conclusion, our data provide reliable evidence for the substantial role of genetic factors in the determination of the phenotypic variability of MCP-1 plasma levels. The association between the osteoclastogenic cytokines and MCP-1 levels in healthy pedigrees is of special interest and might shed light on MCP-1 involvement in bone remodeling.
15548526 Site-directed mutagenesis of CC chemokine receptor 1 reveals the mechanism of action of UC 2005 Feb 11 The chemokine receptor CCR1 and its principal ligand, CCL3/MIP-1alpha, have been implicated in the pathology of several inflammatory diseases including rheumatoid arthritis, multiple sclerosis, and asthma. As such, these molecules are the focus of much research with the ultimate aim of developing novel therapies. We have described previously a non-competitive small molecule antagonist of CCR1 (UCB 35625), which we hypothesized interacted with amino acids located within the receptor transmembrane (TM) helices (Sabroe, I., Peck, M. J., Jan Van Keulen, B., Jorritsma, A., Simmons, G., Clapham, P. R., Williams, T. J., and Pease, J. E. (2000) J. Biol. Chem. 275, 25985-25992). Here we describe an approach to identifying the mechanism by which the molecule antagonizes CCR1. Thirty-three point mutants of CCR1 were expressed transiently in L1.2 cells, and the cells were assessed for their capacity to migrate in response to CCL3 in the presence or absence of UCB 35625. Cells expressing the mutant constructs Y41A (TM helix 1, or TM1), Y113A (TM3), and E287A (TM7) were responsive to CCL3 but resistant to the antagonist, consistent with a role for the TM helices in CCR1 interactions with UCB 35625. Subsequent molecular modeling successfully docked the compound with CCR1 and suggests that the antagonist ligates TM1, 2, and 7 of CCR1 and severely impedes access to TM2 and TM3, a region thought to be perturbed by the chemokine amino terminus during the process of receptor activation. Insights into the mechanism of action of these compounds may facilitate the development of more potent antagonists that show promise as future therapeutic agents in the treatment of inflammatory disease.
17196469 Risk of cardiovascular events in patients receiving celecoxib: a meta-analysis of randomiz 2007 Jan 1 Some nonsteroidal anti-inflammatory drugs (NSAIDs), including cyclooxygenase-2 selective inhibitors, have been associated with increased cardiovascular (CV) events in recent clinical trials or observational studies. To determine whether the cyclooxygenase-2 selective inhibitor celecoxib affects CV risk, the incidence of CV events was analyzed in patients treated with celecoxib, placebo, or nonselective NSAIDs in the clinical trial database for celecoxib using defined Antiplatelet Trialists' Collaboration end points of nonfatal myocardial infarction, nonfatal stroke, and CV death. Patient data were derived from studies in osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, low back pain, and Alzheimer's disease. This meta-analysis included (1) 7,462 patients exposed to celecoxib 200 to 800 mg/day for 1,268 patient-years compared with 4,057 patients treated with placebo for 585 patient-years, and (2) 19,773 patients treated with celecoxib 200 to 800 mg/day for 5,651 patient-years compared with 13,990 patients treated with nonselective NSAIDs (diclofenac, ibuprofen, naproxen, ketoprofen, and loxoprofen) for 4,386 patient-years. CV events were adjudicated by a 3-member expert end point committee (WBW, JSB, PBG) blinded to treatment group and study. The incidence rates of the combined CV events were not significantly different between patients treated with celecoxib and placebo or between those treated with celecoxib and nonselective NSAIDs. Event rates were similar for adjudicated and nonadjudicated data. Dose of celecoxib, the use of aspirin, or the presence of CV risk factors did not alter these results. In conclusion, these analyses failed to demonstrate an increased CV risk with celecoxib relative to placebo and demonstrated a comparable rate of CV events with celecoxib treatment compared with nonselective NSAIDs.
16927021 Low dose leflunomide activates PI3K/Akt signalling in erythroleukemia cells and reduces ap 2006 Oct Rheumatoid arthritis (RA) is characterized by persistent joint synovial tissue inflammation. Leflunomide is an immunomodulatory agent that has been approved for treatment of active RA. In the past few years, uses other than RA treatment have appeared. Leflunomide has been reported to show antitumor potential through inhibition of cancer cell proliferation. We thus tested the antiproliferative potential of leflunomide on HEL and K562 erythroleukemia cells. The findings summarized in this report demonstrate for the first time that low dose leflunomide prolonged survival and reduced apoptosis induced by several anticancer agents in erythroleukemia cells. We showed that in treated cells, leflunomide reduced the signalling pathways involved in promoting apoptosis by reducing p38 MAPK and JNK basal activity. On the other hand, leflunomide transiently activated the ERK signalling pathway and induced a sustained activation of Akt. We also showed that leflunomide reduced caspase-3 activity and DNA fragmentation induced by anticancer agents. By using an inhibitory strategy, we showed that inhibition of Akt activation but not ERK abolished the protective effect of leflunomide. Thus our findings suggested that leflunomide reduced apoptosis induced by anticancer agents through PI3K/Akt signalling activation.
16786167 Expression pattern of matrix metalloproteinase and TIMP genes in fibroblasts derived from 2006 Jul Matrix-degrading proteases play a key role in normal development, wound healing, many diseases such as rheumatoid arthritis and, in particular, tumour invasion. In invasive tumours, these enzymes are expressed by fibroblasts of the tumour stroma. Their expression and activity are tightly regulated at several levels, an important one being transcription. Previous in vitro and in vivo findings pointed to a major role of the Ets-1 transcription factor for this level of regulation. In the present study, we tried to prove this role in fibroblasts. We stimulated wild-type mouse fibroblasts with physiological doses of basic fibroblast growth factor (bFGF, known to induce different proteases and expressed by tumour cells) and compared the results to those obtained in Ets-1 -/- fibroblasts derived from Ets-1 knock-out mice. We found that basal Ets-1 levels are necessary not only for a fast induction of MMPs 2, 3 and 13 by bFGF but also for maintenance of the bFGF-induced expression of tissue inhibitors of metalloproteinases (TIMPs) 1, 2 and 3, which are known not only to inhibit but also participate as activators of certain pro-MMPs.
16638798 Decreased CD161+CD8+ T cells in the peripheral blood of patients suffering from rheumatic 2006 Dec OBJECTIVES: Although it has been reported that the numbers of both CD4(-)CD8(-) and CD4(+) natural killer T (NKT) cells are selectively decreased in the peripheral blood of patients with rheumatic diseases, there have been no reports concerning a novel subpopulation of CD8(+) NKT cells. To examine whether CD161(+)CD8(+) T cells, which are closely related to CD8(+) NKT cells, are also decreased in patients with rheumatic diseases, we have investigated the expression of CD161, together with that of CD28, CD25 and CD62L, on T cells in the peripheral blood of these patients. METHODS: The rheumatic diseases evaluated in this study were systemic lupus erythematosus (SLE) (n= 54), mixed connective-tissue disease (MCTD) (n= 15), systemic sclerosis (SSc) (n= 14), polymyositis/dermatomyositis (PM/DM) (n= 13) and rheumatoid arthritis (RA) (n= 24). Healthy donors were examined as controls (n= 18). The expression of CD161, CD28, CD25 and CD62L on T cells was analysed by flow cytometry. RESULTS: Both the frequency of CD161 expression on CD8(+) cells and the absolute number of CD161(+)CD8(+) cells were significantly decreased in patients with SLE, MCTD, SSc and PM/DM. Only the absolute number of CD161(+)CD8(+) T cells was significantly decreased in RA. CD161 expression on CD28(-)CD8(+) T cells was significantly decreased in SLE, MCTD and SSc. The absolute number of CD161(+)CD8(+)CD62L(-) T cells was significantly decreased in SLE, MCTD and SSc. CONCLUSIONS: Both the frequency and the absolute number of CD161(+)CD8(+) T cells were decreased in the peripheral blood of patients suffering from SLE, MCTD, SSc and PM/DM. This result suggests that there is also an abnormality of NKT cells in the CD8(+) population.
16624877 Differential induction of BLT receptor expression on human endothelial cells by lipopolysa 2006 May 2 Leukotriene (LT) B4 is a powerful chemotactic and immune modulating agent that signals via two receptors denoted BLT1 and BLT2. Here we report that BLT1 and BLT2 are expressed at low levels in an apparently silent state in human umbilical vein endothelial cells (HUVEC). However, treatment with LPS leads to a >10 fold increase in the levels of BLT1 mRNA without any significant effects on BLT2 mRNA. In parallel, LPS also increases the amounts of BLT1 protein. Tumor necrosis factor-alpha (TNF-alpha) increases the expression of BLT2 mRNA approximately 6 times above basal levels with only a modest increase in BLT1 mRNA. Interleukin-1beta causes variable and parallel increases of both BLT1 and BLT2 mRNA. The natural ligand LTB4 also increases BLT1, but not BLT2, mRNA and protein expression. Along with the induction of BLT1 and/or BLT2, HUVEC acquire the capacity to respond to LTB4 with increased levels of intracellular calcium and these signals can be blocked by isotype selective BLT antagonists, CP-105696 and LY-255283. In addition, treatment of HUVEC with LTB4 causes increased release of both nitrite, presumably reflecting nitric oxide (NO), and monocyte chemoattractant protein-1. Our data indicate that expression of functional BLT receptors may occur at the surface of endothelial cells in response to LPS, cytokines, and ligand, which in turn may have functional consequences during the early vascular responses to inflammation. Moreover, the results point to BLT receptors as potential targets for pharmacological intervention in LT-dependent inflammatory diseases such as asthma, rheumatoid arthritis, and arteriosclerosis.