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ID PMID Title PublicationDate abstract
21041351 Presence of comorbid somatic disorders among patients referred to mental health care in th 2010 Nov OBJECTIVE: Referral to mental health care was examined among persons with mental disorders with and without comorbid somatic conditions to determine whether certain conditions may make detection of mental disorders by primary care physicians more or less likely. METHODS: Receipt of mental health care in the primary and specialty care settings by respondents to the Netherlands Mental Health Survey and Incidence Study who had mood disorders (N=573), anxiety disorders (N=912), and substance use disorders (N=533) was examined, first broadly by any of 31 somatic conditions and then by each of the five most common conditions. RESULTS: Broadly, those with anxiety disorders and a somatic condition were more likely to use care in both settings (adjusted relative risk ratios [RRRs]=1.75 and 1.58 for primary and specialty care, respectively), and those with substance use disorders and a somatic condition were more likely to use specialty care (RRR=2.15). More narrowly, use of specialty care by persons with mood disorders was three times as likely for those with rheumatoid arthritis or a digestive tract disorder (RRRs=3.04 and 2.92). For anxiety disorders, specialty care was more likely for those with chronic backache (RRR=2.14) or a digestive tract disorder (RRR=3.56). For substance use disorders, those with chronic backache were six times as likely to use specialty care (RRR=6.05) and those with a digestive tract disorder were three times as likely (RRR=3.09). CONCLUSIONS: Poor somatic health in general seemed to increase the likelihood of use of mental health care for persons with anxiety or substance use disorders, but not for those with mood disorders. Having certain somatic conditions appeared to enhance recognition and treatment of three common mental disorders.
21040744 Allograft inflammatory factor-1 is overexpressed and induces fibroblast chemotaxis in the 2011 Mar 30 Allograft inflammatory factor (AIF)-1 has been identified in chronic rejection of rat cardiac allografts and is thought to be involved in the immune response. We previously showed that AIF-1 was strongly expressed in synovial tissues in rheumatoid arthritis and that rAIF-1 increased the IL-6 production of synoviocytes and peripheral blood mononuclear cells. Recently, the expression of AIF-1 has been reported in systemic sclerosis (SSc) tissues, whose clinical features and histopathology are similar to those of chronic graft-vs-host disease (GVHD). To clarify the pathogenic mechanism of fibrosis, we examined the expression and function of AIF in sclerodermatous (Scl) GVHD mice. We demonstrated that immunoreactive AIF-1 and IL-6 were significantly expressed in infiltrating mononuclear cells and fibroblasts in thickened skin of Scl GVHD mice compared with control. The immunohistochemical findings were confirmed by Western blot analysis. Wound healing assay also revealed that rAIF-1 increased the migration of normal human dermal fibroblasts (NHDF) directly, but cell growth assay did not show that rAIF-1 increased the proliferation of them. These findings suggest that AIF-1, which can induce the migration of fibroblasts and the production of IL-6 in affected skin tissues, is an important molecule promoting fibrosis in GVHD. Although the biological function of AIF-1 has not been completely elucidated, AIF-1 can induce IL-6 secretion on mononuclear cells and fibroblast chemotaxis. AIF-1 may accordingly provide an attractive new target for antifibrotic therapy in SSc as well as Scl GVHD.
20837476 Inhibition of osteoclast bone resorption by disrupting vacuolar H+-ATPase a3-B2 subunit in 2010 Nov 26 Vacuolar H(+)-ATPases (V-ATPases) are highly expressed in ruffled borders of bone-resorbing osteoclasts, where they play a crucial role in skeletal remodeling. To discover protein-protein interactions with the a subunit in mammalian V-ATPases, a GAL4 activation domain fusion library was constructed from an in vitro osteoclast model, receptor activator of NF-κB ligand-differentiated RAW 264.7 cells. This library was screened with a bait construct consisting of a GAL4 binding domain fused to the N-terminal domain of V-ATPase a3 subunit (NTa3), the a subunit isoform that is highly expressed in osteoclasts (a1 and a2 are also expressed, to a lesser degree, whereas a4 is kidney-specific). One of the prey proteins identified was the V-ATPase B2 subunit, which is also highly expressed in osteoclasts (B1 is not expressed). Further characterization, using pulldown and solid-phase binding assays, revealed an interaction between NTa3 and the C-terminal domains of both B1 and B2 subunits. Dual B binding domains of equal affinity were observed in NTa, suggesting a possible model for interaction between these subunits in the V-ATPase complex. Furthermore, the a3-B2 interaction appeared to be moderately favored over a1, a2, and a4 interactions with B2, suggesting a mechanism for the specific subunit assembly of plasma membrane V-ATPase in osteoclasts. Solid-phase binding assays were subsequently used to screen a chemical library for inhibitors of the a3-B2 interaction. A small molecule benzohydrazide derivative was found to inhibit osteoclast resorption with an IC(50) of ∼1.2 μm on both synthetic hydroxyapatite surfaces and dentin slices, without significantly affecting RAW 264.7 cell viability or receptor activator of NF-κB ligand-mediated osteoclast differentiation. Further understanding of these interactions and inhibitors may contribute to the design of novel therapeutics for bone loss disorders, such as osteoporosis and rheumatoid arthritis.
20831919 Gymnasterkoreayne F inhibits osteoclast formation by suppressing NFATc1 and DC-STAMP expre 2010 Nov Osteoclasts are multinucleated cells that have a unique role in bone degradation. Modulation of osteoclast formation and/or its activity is an important approach for the treatment of bone-destructive diseases such as osteoporosis and rheumatoid arthritis. In this study, Gymnasterkoreayne F (GK-F), a natural compound isolated from Gymnaster koraiensis, was found to inhibit osteoclast differentiation from primary bone marrow-derived macrophages (BMMs) in a dose-dependent manner. The inhibition occurred through the suppression of nuclear factor of activated T cells c1 (NFATc1) expression, which then led to the decreased levels of osteoclastogenic markers, including Cathepsin K and tartrate-resistant acid phosphatase (TRAP). In addition, GK-F abolished pre-osteoclast fusion induced by the receptor activator of nuclear factor kappa B ligand (RANKL), lipopolysaccharide (LPS) and TNF-α. Reflecting its inhibitory effects on cell-cell fusion, GK-F attenuated the gene expression of an essential molecule of osteoclast fusion, the dendritic cell-specific transmembrane protein (DC-STAMP). Furthermore, GK-F inhibited the bone resorptive activity of differentiated osteoclasts through its ability to block RANKL-induced actin ring formation. The effect was associated with a significant decrease in the induction of β3 integrin expression, which is an essential regulator of osteoclast cytoskeletal function. Taken together, these results suggest that GK-F might be useful as a therapeutic agent for bone resorption-related diseases.
20639492 P2X(7) receptor-mediated release of cathepsins from macrophages is a cytokine-independent 2010 Aug 15 The ATP-gated P2X(7) receptor (P2X(7)R) is a promising therapeutic target in chronic inflammatory diseases with highly specific antagonists currently under clinical trials for rheumatoid arthritis. Anti-inflammatory actions of P2X(7)R antagonists are considered to result from inhibition of P2X(7)R-induced release of proinflammatory cytokines from activated macrophages. However, P2X(7)Rs are also expressed in resting macrophages, suggesting that P2X(7)R may also signal via cytokine-independent mechanisms involved in joint disease. In this study, we examined P2X(7)R function in resting human lung macrophages and mouse bone marrow-derived macrophages and found that ATP induced rapid release of the lysosomal cysteine proteases cathepsin B, K, L, and S and that was independent of the presence of the proinflammatory cytokines IL-1beta and IL-18. Cathepsins released into the medium were effective to degrade collagen extracellular matrix. ATP-induced cathepsin release was abolished by P2X(7)R antagonists, absent from P2X(7)R(-/-) mouse macrophages, and not associated with cell death. Our results suggest P2X(7)R activation may play a novel and direct role in tissue damage through release of cathepsins independently of its proinflammatory actions via IL-1 cytokines.
20565929 Predicting the risk of chronic Kidney Disease in men and women in England and Wales: prosp 2010 Jun 21 BACKGROUND: Chronic Kidney Disease is a major cause of morbidity and interventions now exist which can reduce risk. We sought to develop and validate two new risk algorithms (the QKidney Scores) for estimating (a) the individual 5 year risk of moderate-severe CKD and (b) the individual 5 year risk of developing End Stage Kidney Failure in a primary care population. METHODS: We conducted a prospective open cohort study using data from 368 QResearch general practices to develop the scores. We validated the scores using two separate sets of practices--188 separate QResearch practices and 364 practices contributing to the THIN database.We studied 775,091 women and 799,658 men aged 35-74 years in the QResearch derivation cohort, who contributed 4,068,643 and 4,121,926 person-years of observation respectively.We had two main outcomes (a) moderate-severe CKD (defined as the first evidence of CKD based on the earliest of any of the following: kidney transplant; kidney dialysis; diagnosis of nephropathy; persistent proteinuria; or glomerular filtration rate of < 45 mL/min) and (b) End Stage Kidney Failure.We derived separate risk equations for men and women. We calculated measures of calibration and discrimination using the two separate validation cohorts. RESULTS: Our final model for moderate-severe CKD included: age, ethnicity, deprivation, smoking, BMI, systolic blood pressure, diabetes, rheumatoid arthritis, cardiovascular disease, treated hypertension, congestive cardiac failure; peripheral vascular disease, NSAID use and family history of kidney disease. In addition, it included SLE and kidney stones in women. The final model for End Stage Kidney Failure was similar except it did not include NSAID use.Each risk prediction algorithms performed well across all measures in both validation cohorts. For the THIN cohort, the model to predict moderate-severe CKD explained 56.38% of the total variation in women and 57.49% for men. The D statistic values were high with values of 2.33 for women and 2.38 for men. The ROC statistic was 0.875 for women and 0.876 for men. CONCLUSIONS: These new algorithms have the potential to identify high risk patients who might benefit from more detailed assessment, closer monitoring or interventions to reduce their risk.
20550744 Cocoa polyphenols suppress TNF-α-induced vascular endothelial growth factor expression by 2010 Oct Cocoa polyphenols have antioxidant and anti-inflammatory effects. TNF-α is a pro-inflammatory cytokine that has a vital role in the pathogenesis of inflammatory diseases such as cancer and psoriasis. Vascular endothelial growth factor (VEGF) expression is associated with tumorigenesis, CVD, rheumatoid arthritis and psoriasis. We tested whether cocoa polyphenol extract (CPE) inhibited TNF-α-induced VEGF expression in promotion-sensitive JB6 mouse epidermal cells. CPE significantly inhibited TNF-α-induced up-regulation of VEGF via reducing TNF-α-induced activation of the nuclear transcription factors activator protein-1 (AP-1) and NF-κB, which are key regulators of VEGF expression. CPE also inhibited TNF-α-induced phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase. CPE blocked activation of their downstream kinases, p70 kDa ribosomal protein S6 kinase and p90 kDa ribosomal protein S6 kinase. CPE suppressed phosphoinositide 3-kinase (PI3K) activity via binding PI3K directly. CPE did not affect TNF-α-induced phosphorylation of mitogen-activated protein kinase kinase-1 (MEK1) but suppressed TNF-α-induced MEK1 activity. Collectively, these results indicate that CPE reduced TNF-α-induced up-regulation of VEGF by directly inhibiting PI3K and MEK1 activities, which may contribute to its chemopreventive potential.
20436073 Low-dose infliximab (3 mg/kg) significantly reduces spinal inflammation on magnetic resona 2010 Aug 1 OBJECTIVE: To evaluate the influence of low-dose infliximab (IFX) on spinal inflammation scored by magnetic resonance imaging (MRI). The dose recommended for rheumatoid arthritis (3 mg/kg) is also clinically effective for ankylosing spondylitis (AS), although effects on spinal inflammation as defined by MRI have yet to be described in a placebo-controlled trial. METHODS: In a 12-week double-blind period, patients were randomized 1:1 to receive either IFX 3 mg/kg at 0, 2, and 6 weeks, or placebo. Spinal inflammation in discovertebral units (DVU) was measured by the Spondyloarthritis Research Consortium of Canada (SPARCC) MRI Index at baseline and 12 weeks by 3 readers blinded to timepoint and treatment allocation. We also compared reliability and discrimination of the SPARCC MRI index based on evaluation of the entire spine (23 DVU score) compared to assessment of only the 6 most severely affected DVU (6 DVU score). RESULTS: At Week 12, patients treated with IFX experienced mean reductions of 55.1% and 57.2% in the 6 DVU and 23 DVU SPARCC scores, respectively, compared with a mean increase of 5.8% and decrease of 3.4% in 6 DVU and 23 DVU scores, respectively, for patients taking placebo (p < 0.001). A large treatment effect (Guyatt's effect size >or= 1.7) and high reliability was evident and comparable between 6 DVU and 23 DVU scoring methods. CONCLUSION: Treatment with low-dose IFX leads to a large treatment effect on spinal inflammation as measured by MRI. Scoring for inflammation of only the most severely affected regions of the spine by MRI is comparable to assessment of the entire spine.
20185962 Fractalkine-induced endothelial cell migration requires MAP kinase signaling. 2010 BACKGROUND/AIMS: Angiogenesis is a well-established characteristic in the rheumatoid arthritis (RA) synovial pannus. We have previously demonstrated that fractalkine (Fkn/ CX3CL1) expression is significantly increased in the RA joint and that fractalkine induces angiogenesis. In this work we studied mechanisms through which Fkn functions as an angiogenic mediator. METHODS: Human microvascular endothelial cells (HMVECs) and human umbilical vein endothelial cells (HUVECs) were stimulated with Fkn and analyzed by Western blotting or stained with Alexa Fluor 488 phalloidin for F-actin to characterize the time frame of cytoskeletal rearrangement. Fkn-induced HUVEC chemotaxis was performed in the presence and absence of MAP kinase inhibitors. RESULTS: Phalloidin staining of F-actin revealed significant cytoskeletal rearrangements in HUVECs and HMVECs starting as early as 10 min after Fkn stimulation. Western blotting demonstrated that HUVEC and HMVEC stimulation with Fkn for 1-30 min resulted in phosphorylation of JNK. Fkn also induces significant phosphorylation of Erk 1/2 in HUVECs over a time course ranging from 1 to 15 min. A somewhat similar time course (5-15 min) was detected for Erk 1/2 phosphorylation in HMVECs. Inhibitors of either JNK or Erk 1/2 nearly abolish Fkn-induced HUVEC migration. CONCLUSIONS: We demonstrate that Fkn induces significant alterations in cytoskeletal structure and specifically activates the MAP kinases, JNK and Erk 1/2, both of which appear necessary for endothelial cell migration. Our results suggest that the endogenous Fkn present in the RA joint may induce angiogenesis through activation of the JNK and Erk 1/2 pathways.
20173391 TNF-alpha: an activator of CD4+FoxP3+TNFR2+ regulatory T cells. 2010 TNF-alpha (TNF) is a pleiotropic cytokine which can have proinflammatory or immunosuppressive effects, depending on the context, duration of exposure and disease state. The basis for the opposing actions of TNF remains elusive. The growing appreciation of CD4+FoxP3+ regulatory T cells (Tregs), which comprise approximately 10% of peripheral CD4 cells, as pivotal regulators of immune responses has provided a new framework to define the cellular and molecular basis underlying the contrasting action of TNF. TNF by itself can overcome the profound anergic state of T cell receptor-stimulated Tregs. Furthermore, in concert with IL-2, TNF selectively activates Tregs, resulting in proliferation, upregulation of FoxP3 expression and increases in their suppressive activity. Both human and mouse Tregs predominantly express TNFR2, making it possible for TNF to enhance Treg activity, which helps limit the collateral damage caused by excessive immune responses and eventually terminates immune response. TNFR2-expressing CD4+FoxP3+ Tregs comprise approximately 40% of peripheral Tregs in normal mice and present the maximally suppressive subset of Tregs. In this review, studies describing the action of TNF on Treg function will be discussed. The role of Tregs in the autoimmune disorders and cancer as well as the effect of anti-TNF therapy on Tregs, especially in rheumatoid arthritis, will also be considered.
20170280 Comparative renal excretion of VX-702, a novel p38 MAPK inhibitor, and methotrexate in the 2010 Mar CONTEXT: VX-702 is a novel p38 mitogen-activated protein kinase inhibitor being developed to treat rheumatoid arthritis. OBJECTIVE: To characterize the renal excretion profile of VX-702 using the isolated perfused rat kidney (IPRK) model. METHODS: Studies were performed to assess the dose linearity of VX-702 excretion and to evaluate the effect of inhibitors of organic anion (probenecid) and organic cation (cimetidine) transport systems on VX-702 disposition. VX-702 excretion was studied over a range of doses targeting concentrations between 100 and 600 ng/mL. VX-702 (600 ng/mL) was also co-perfused with probenecid (1 mM) and cimetidine (2 mM). The results were compared to parallel experiments performed with methotrexate (MTX). RESULTS: VX-702 excretion was linear over the range of doses studied, and clearance data were consistent with net reabsorption by the kidney. Transport inhibition studies indicate that VX-702 is not a substrate for renal organic anion and organic cation transport systems. MTX (500 ng/mL) also displayed net reabsorption in the IPRK, but secretory transport was inhibited upon co-administration with probenecid. This finding is consistent with previous IPRK studies that demonstrated inhibitory effects of NSAIDS on MTX excretion. CONCLUSION: Overall, this study suggests that a renal drug-drug interaction between VX-702 and MTX would be unlikely if these medications were co-administered.
19900598 Inhibition of osteoclast differentiation and bone resorption by rotenone, through down-reg 2010 Mar Osteoclasts are responsible for bone erosion in diseases as diverse as osteoporosis, periodontitis, and rheumatoid arthritis. Natural plant-derived products have received recent attention as potential therapeutic and preventative drugs in human disease. The effect of rotenone in RANKL-induced osteoclast differentiation was examined in this study. Rotenone inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages (BMMs) in a dose-dependent manner without any evidence of cytotoxicity. The mRNA expression of c-Fos, NFATc1, TRAP, and OSCAR in RANKL-treated BMMs was inhibited by rotenone treatment. Rotenone strongly inhibited p38 and ERK phosphorylation and I-kappaB degradation in RANKL-stimulated BMMs, and did not inhibit JNK phosphorylation. Further, RANKL-induced c-Fos and NFATc1 protein expression was suppressed by rotenone. Rotenone additionally inhibited the bone resorptive activity of differentiated osteoclasts. A lipopolysaccharide (LPS)-induced bone erosion study was also performed to assess the effects of rotenone in vivo. Mice treated with rotenone demonstrated marked attenuation of bone erosion based on Micro CT and histologic analysis of femurs. These results collectively suggested that rotenone demonstrated inhibitory effects on osteoclast differentiation in vitro and suppressed inflammatory bone loss in vivo. Rotenone may therefore serve as a useful drug in the prevention of bone loss.
19856190 C1 lateral mass screw-induced occipital neuralgia: a report of two cases. 2010 Mar C1-2 polyaxial screw-rod fixation is a relatively new technique. While recognizing the potential for inadvertent vertebral artery injury, there have been few reports in the literature outlining all the possible complications. Aim of this study is to review all cases of C1 lateral mass screws insertion with emphasis on the evaluation of potential structures at risk during the procedure. We retrospectively reviewed all patients in our unit who had C1 lateral mass screw insertion over a 2-year period. The C1 lateral mass screw was inserted as part of an atlantoaxial stabilization or incorporated into a modular occiput/subaxial construct. Outcome measures included clinical and radiological parameters. Clinical indicators included age, gender, neurologic status, surgical indication and the number of levels stabilized. Intraoperative complications including blood loss, vertebral artery injury or dural tears were recorded. Postoperative pain distribution and neurological deficit were recorded. Radiological indicators included postoperative plain radiographs to assess sagittal alignment and to check for screw malposition or construct failure. A total of 18 lateral mass screws were implanted in 9 patients. There were three male and six female patients who had C1 lateral mass screw insertion in this unit. Two patients had atlantoaxial stabilization for C2 fracture. There were four patients with rheumatoid arthritis whose C1 lateral mass screws were inserted as part of an occipitocervical or subaxial cervical stabilization. There was no vertebral artery injury, no cerebrospinal fluid leak and minimal blood loss in all patients. Three patients developed postoperative occipital neuralgia. This neuralgia was transient, in one of the patients having settled at 6-week follow-up. In the other two patients the neuralgia was unresolved at time of latest follow-up but was adequately controlled with appropriate pain management. Postoperatively no patient had radiographic evidence of construct failure and all demonstrated excellent sagittal alignment. It has been reported that the absence of threads on the upper portion of the long shank screw may protect against neural irritation. However, insertion of the C1 lateral mass screw necessitates careful caudal retraction of the C2 dorsal root ganglion. The insertion point for the C1 lateral mass screw is at the junction of the C1 posterior arch and the midpoint of the posterior inferior part of the C1 lateral mass. Two patients in our series suffered occipital neuralgia post-insertion of C1 lateral mass screws. This highlights the potential for damage to the C2 nerve root during C1 lateral mass screw placement.
19658442 Neutrophilic dermatoses: a review of current treatment options. 2009 Sweet syndrome, pyoderma gangrenosum, and subcorneal pustular dermatosis are neutrophilic dermatoses - conditions that have an inflammatory infiltrate consisting of mature polymorphonuclear leukocytes. The neutrophils are usually located within the dermis in Sweet syndrome and pyoderma gangrenosum; however, in subcorneal pustular dermatosis, they are found in the upper layers of the epidermis. Sweet syndrome, also referred to as acute febrile neutrophilic dermatosis, is characterized by pyrexia, elevated neutrophil count, painful erythematous cutaneous lesions that have an infiltrate of mature neutrophils typically located in the upper dermis, and prompt clinical improvement following the initiation of systemic corticosteroid therapy. Classical, malignancy-associated, and drug-induced variants of Sweet syndrome exist. Pyoderma gangrenosum is characterized by painful, enlarging necrotic ulcers with bluish undermined borders surrounded by advancing zones of erythema; its clinical variants include: ulcerative or classic, pustular, bullous or atypical, vegetative, peristomal, and drug-induced. Subcorneal pustular dermatosis is an uncommon relapsing symmetric pustular eruption that involves flexural and intertriginous areas; it can be idiopathic or associated with cancer, infections, medications, and systemic diseases. Since Sweet syndrome, pyoderma gangrenosum, and subcorneal pustular dermatosis share not only the same inflammatory cell but also similar associated systemic diseases, it is not surprising that the concurrent or sequential development of these neutrophilic dermatoses has been observed in the same individual. Also, it is not unexpected that several of the effective therapeutic interventions - including systemic drugs, topical agents, and other treatment modalities - for the management of these dermatoses are the same. The treatment of choice for Sweet syndrome and idiopathic pyoderma gangrenosum is systemic corticosteroids; however, for subcorneal pustular dermatosis, dapsone is the drug of choice. Yet, tumor necrosis factor-alpha antagonists are becoming the preferred choice when pyoderma gangrenosum is accompanied by inflammatory bowel disease or rheumatoid arthritis. Potassium iodide and colchicine are alternative first-line therapies for Sweet syndrome and indomethacin (indometacin), clofazimine, cyclosporine (ciclosporin), and dapsone are second-line treatments. Cyclosporine is effective in the acute management of pyoderma gangrenosum; however, when tapering the drug, additional systemic agents are necessary for maintaining the clinical response. In some patients with subcorneal pustular dermatosis, systemic corticosteroids may be effective; yet, systemic retinoids (such as etretinate and acitretin) have effectively been used for treating this neutrophilic dermatosis - either as monotherapy or in combination with dapsone or as a component of phototherapy with psoralen and UVA radiation. Topical agents can have an adjuvant role in the management of these neutrophilic dermatoses; however, high-potency topical corticosteroids may successfully treat localized manifestations of Sweet syndrome, pyoderma gangrenosum, and subcorneal pustular dermatosis. Intralesional corticosteroid therapy for patients with Sweet syndrome and pyoderma gangrenosum, hyperbaric oxygen and plasmapheresis for patients with pyoderma grangrenosum, and phototherapy for patients with subcorneal pustular dermatosis are other modalities that have been used effectively for treating individuals with these neutrophilic dermatoses.
19508391 Tripterine prevents endothelial barrier dysfunction by inhibiting endogenous peroxynitrite 2009 Jul BACKGROUND AND PURPOSE: Tripterine is an inhibitor of heat shock protein 90 and an active component of Tripterygium wilfordii Hook F., which is used in traditional Chinese medicine to treat inflammatory diseases such as rheumatoid arthritis. We hypothesized that tripterine inhibits endogenous peroxynitrite formation and thereby prevents endothelial barrier dysfunction. EXPERIMENTAL APPROACH: Effects of tripterine were investigated on endothelial barrier function, inducible nitric oxide synthase (iNOS) expression, nicotinamide adenine dinucleotide phasphate (NADPH) oxidase activity, 3-nitrotyrosine formation, protein phosphatase type 2A (PP2A) activity, activation of extracellular-regulated kinase (ERK), c-Jun terminal kinase (JNK) and Janus kinase (Jak2), and degradation of IkappaB in microvascular endothelial cells exposed to pro-inflammatory stimulus [lipopolysaccharide (LPS) + interferon gamma (IFNgamma)] and on vascular permeability in air pouches of mice injected with LPS + IFNgamma. KEY RESULTS: LPS + IFNgamma caused an increase in monolayer permeability, induction of iNOS and NADPH oxidase type 1 (Nox1) proteins, formation of superoxide, nitric oxide and 3-nitrotyrosine, and increase in PP2A activity in endothelial cells. These effects of LPS + IFNgamma were diminished by tripterine (50-200 nM). Further, LPS + IFNgamma-induced expression of iNOS and Nox1 was attenuated by the mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor PD98059, the JNK inhibitor SP600125, the Jak2 inhibitor AG490 and the NFkappaB inhibitor MG132, but not by the p38 mitogen-activated protein kinase inhibitor SB203580. LPS + IFNgamma stimulated phosphorylation of ERK, JNK and Jak2, and degradation of IkappaB, but only Jak2 phosphorylation was sensitive to tripterine (50-200 nM). Further, tripterine diminished the increased vascular permeability in inflamed air pouches. CONCLUSION AND IMPLICATIONS: Our results indicate that, by preventing Jak2-dependent induction of iNOS and Nox1, tripterine inhibits peroxynitrite precursor synthesis, attenuates the increased activity of PP2A and consequently protects endothelial barrier function.
19429333 Bee venom suppresses LPS-mediated NO/iNOS induction through inhibition of PKC-alpha expres 2009 May 4 ETHNOPHARMACOLOGICAL RELEVANCE: Bee venom (BV) is a traditional Korean medicine that has been widely used with satisfactory results in the treatment of some immune-related diseases, especially rheumatoid arthritis. AIM OF THE STUDY: The purpose of this study is to elucidate the molecular mechanism underlying the anti-inflammatory effects of BV, which is used in the treatment of various inflammatory diseases in traditional Korean medicine. We evaluated the anti-inflammatory effect of BV on NO generation and iNOS expression by LPS in rat C6 glioma cells. MATERIAL AND METHODS: BV was obtained from the National Institute of Agricultural Science and Technology (NIAST) of Korea. Nitrite measurement, Immuno blot analysis, Reverse transcriptase-PCR and Electrophoretic mobility shift assay (EMSA) were used for assessment. RESULTS: BV suppressed the LPS-induced NO generation and iNOS expression, and it also inhibited the expressions of LPS-induced pro-inflammatory molecules including Cox-2 and IL-1 beta in rat C6 glioma cells. Then, BV inhibited LPS-induced expression of PKC-alpha and MEK/ERK, not p38 and JNK. Moreover, inhibition of LPS-induced iNOS expression by BV was dependent on transcriptional activities of AP-1/NF-kappaB through MEK/ERK pathway. CONCLUSION: These results indicate that BV suppresses LPS-induced iNOS activation through regulation of PKC-alpha. Accordingly, BV exerts a potent suppressive effect on pro-inflammatory responses in rat C6 glioma cells.
19349147 The genetics and epigenetics of autoimmune diseases. 2009 Aug Self tolerance loss is fundamental to autoimmunity. While understanding of immune regulation is expanding rapidly, the mechanisms causing loss of tolerance in most autoimmune diseases remain elusive. Autoimmunity is believed to develop when genetically predisposed individuals encounter environmental agents that trigger the disease. Recent advances in the genetic and environmental contributions to autoimmunity suggest that interactions between genetic elements and epigenetic changes caused by environmental agents may be responsible for inducing autoimmune disease. Genetic loci predisposing to autoimmunity are being identified through multi-center consortiums, and the number of validated genes is growing rapidly. Recent reports also indicate that the environment can contribute to autoimmunity by modifying gene expression through epigenetic mechanisms. This article will review current understanding of the genetics and epigenetics of lupus, rheumatoid arthritis, multiple sclerosis and type 1 diabetes, using systemic lupus erythematosus as the primary example. Other autoimmune diseases may have a similar foundation.
20192600 Chemoprevention of 1,2-dimethylhydrazine-induced colon carcinogenesis by a non-steroidal a 2009 Etoricoxib, a highly selective cyclooxygenase- 2 (COX-2) inhibitor (a non steroidal anti-inflammatory drug) used for the treatment of rheumatoid arthritis and osteoarthritis, has been newly marketed and studied for the chemopreventive response in the 1,2-dimethylhydrazine dihydrochloride (DMH) induced rat colon cancer model. Male Sprague-Dawley rats were divided into four groups. Group I served as the Control and received the vehicle treatment, while Groups 2 and 3 were administered freshly prepared DMH (30 mg/kg body weight, subcutaneously) in 1mM EDTA-saline (pH 7.0). Groups 3 and 4 received Etoricoxib (0.64 mg/kg body weight, orally) daily prepared in 0.5% carboxymethyl cellulose. After a 6 week treatment period, animals were sacrificed and the colons were subjected to macroscopic and histopathological studies. Well characterized pre-neoplastic features such as multiple plaque lesions (MPLs), aberrant crypts (ACs) and aberrant crypt foci (ACF) were found in the DMH group. The number was reduced in DMH + Etoricoxib group, while very few MPLs and ACFs were recorded in the Etoricoxib only group. Also, histologically well characterized dysplasia and hyperplasia were observed in DMH treated group. The simultaneous administration of DMH and Etoricoxib reduced these features. To study apoptosis, colonocytes were isolated by metal chelation from colonic sacs and studied by fluorescent staining. The DMH treated animals produced much less apoptotic nuclei as compared to the Control. The number of apoptotic nuclei was also found higher in the DMH + Etoricoxib group as well as in Etoricoxib only group. Studies of a nuclear transcription factor (NF-kB) and COX-2 by Western blot analysis and immunohistochemistry demonstrated expression of both to be elevated in the DMH treated group but reduced in the DMH + Etoricoxib group. Expression was also low in the Etoricoxib only group. It may be concluded that the drug, Etoricoxib, has the potential to reduce DMH induced colon cancer development.
19622164 Adapted Boolean network models for extracellular matrix formation. 2009 Jul 21 BACKGROUND: Due to the rapid data accumulation on pathogenesis and progression of chronic inflammation, there is an increasing demand for approaches to analyse the underlying regulatory networks. For example, rheumatoid arthritis (RA) is a chronic inflammatory disease, characterised by joint destruction and perpetuated by activated synovial fibroblasts (SFB). These abnormally express and/or secrete pro-inflammatory cytokines, collagens causing joint fibrosis, or tissue-degrading enzymes resulting in destruction of the extra-cellular matrix (ECM).We applied three methods to analyse ECM regulation: data discretisation to filter out noise and to reduce complexity, Boolean network construction to implement logic relationships, and formal concept analysis (FCA) for the formation of minimal, but complete rule sets from the data. RESULTS: First, we extracted literature information to develop an interaction network containing 18 genes representing ECM formation and destruction. Subsequently, we constructed an asynchronous Boolean network with biologically plausible time intervals for mRNA and protein production, secretion, and inactivation. Experimental gene expression data was obtained from SFB stimulated by TGFbeta1 or by TNFalpha and discretised thereafter. The Boolean functions of the initial network were improved iteratively by the comparison of the simulation runs to the experimental data and by exploitation of expert knowledge. This resulted in adapted networks for both cytokine stimulation conditions. The simulations were further analysed by the attribute exploration algorithm of FCA, integrating the observed time series in a fine-tuned and automated manner. The resulting temporal rules yielded new contributions to controversially discussed aspects of fibroblast biology (e.g., considerable expression of TNF and MMP9 by fibroblasts stimulation) and corroborated previously known facts (e.g., co-expression of collagens and MMPs after TNFalpha stimulation), but also revealed some discrepancies to literature knowledge (e.g., MMP1 expression in the absence of FOS). CONCLUSION: The newly developed method successfully and iteratively integrated expert knowledge at different steps, resulting in a promising solution for the in-depth understanding of regulatory pathways in disease dynamics. The knowledge base containing all the temporal rules may be queried to predict the functional consequences of observed or hypothetical gene expression disturbances. Furthermore, new hypotheses about gene relations were derived which await further experimental validation.
19199943 Tyrosine kinases and inflammatory signalling. 2009 Feb The activity of tyrosine kinases is central to many cellular processes, and accumulating evidence suggests that their role in inflammation is no less profound. Three main tyrosine kinase families, the Src, Tec and Syk kinase families are intimately involved in TLR signalling, the critical first step in cellular recognition of invading pathogens and tissue damage. Their activity results in changes in gene expression in affected cells. Key amongst these genes are the cytokines, which orchestrate both the duration and extent of inflammation. Tyrosine kinases also play important roles in cytokine function, and are implicated in signalling through both pro- and anti-inflammatory cytokines such as TNF, IL-6 and IL-10. Thus, strategies to modulate tyrosine kinase activity have significant therapeutic potential in combating the chronic inflammatory state that is typical of many major health issues that face us today, including Rheumatoid Arthritis, Cardiovascular disease and cancer. Here we review current knowledge of the role of tyrosine kinases in inflammation with particular emphasis on their role in TLR signalling.