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ID PMID Title PublicationDate abstract
18242157 Activation of peroxisome proliferator-activated receptor gamma inhibits TNF-alpha-mediated 2008 Apr Tumor necrosis factor-alpha (TNF-alpha) plays critical roles in bone resorption at the site of inflammatory joints. The aim of this study is to evaluate the effect of peroxisome proliferator-activated receptor gamma (PPAR-gamma) agonists, a new class of anti-inflammatory compounds, on TNF-alpha-mediated osteoclastogenesis in human monocytes. Human monocytes were differentiated into osteoclasts in the presence of TNF-alpha and macrophage colony-stimulating factor. Tartrate-resistant acid phosphatase (TRAP) staining and a pit formation assay using dentin were used for the identification of activated osteoclasts. The protein and gene expressions of transcription factors were determined by immunofluorescence and real-time RT-PCR analysis, respectively. TNF-alpha-induced osteoclast generation from human peripheral monocytes in a dose-dependent manner, and the induction was not inhibited by osteoprotegerin, a decoy receptor for receptor activator of NF-kappaB ligand. The addition of PPAR-gamma agonists, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) or ciglitazone, to the culture resulted in a remarkably reduced number of generated osteoclasts. In addition, both agonists inhibited the protein and gene expressions of nuclear factor of activated T-cell isoform c1 (NFATc1), c-Fos, c-Jun and NF-kappaB p65, which are known to be associated with osteoclastogenesis. GW9662, an antagonist of PPAR-gamma, fully rescued ciglitazone-induced inhibition, but did not affect 15d-PGJ2-induced inhibition. Monocyte chemoattractant protein-1 (MCP-1), a CC chemokine related to osteoclastogenesis, was induced during TNF-alpha-mediated osteoclast differentiation, and the neutralizing antibody to MCP-1 reduced osteoclast formation by about 40%. 15d-PGJ2 and ciglitazone blocked the induction of MCP-1 by TNF-alpha. Moreover, the addition of MCP-1 rescued the inhibition of TRAP-positive multinucleated cell (TRAP-MNCs) formation by 15d-PGJ2 and ciglitazone, although generated TRAP-MNCs had no capacity to resorb dentin slices. Our data demonstrate that 15d-PGJ2 and ciglitazone down-regulate TNF-alpha-mediated osteoclast differentiation in human cells, in part via suppression of the action of MCP-1. These PPAR-gamma agonists may be a promising therapeutic application for rheumatoid arthritis and inflammatory bone-resorbing diseases.
18216477 Association between psoriasis and the metabolic syndrome. A cross-sectional study. 2008 BACKGROUND: Previous reports have shown an association between inflammatory diseases such as systemic lupus erythematosus or rheumatoid arthritis and the metabolic syndrome. Recent data demonstrate that psoriasis is an inflammatory disease, suggesting that psoriasis may be one of the components of the metabolic syndrome. OBJECTIVE: To assess the association between psoriasis and the metabolic syndrome. METHODS: A cross-sectional study was performed utilizing the database of the Clalit Health Services. Case patients were defined as patients with a diagnosis of psoriasis vulgaris. Controls were randomly selected from the list of Clalit Health Services enrollees. The proportions of components of the metabolic syndrome (ischemic heart disease, hypertension, diabetes, obesity and dyslipidemia) were compared between case and control patients by univariate analyses. chi(2) tests were used to compare categorical parameters between the groups. Logistic and linear regression models served to measure the association between psoriasis and the metabolic syndrome. RESULTS: The study included 16,851 patients with psoriasis and 48,681 controls. In the case group, there were 8,449 men (50.1%) and 8,402 women (49.9%), with a mean age of 42.7 years (SD = 20.3, range = 2-111). Diabetes mellitus was present in 13.8% of the patients with psoriasis as compared to 7.3% of the controls (p < 0.001). Hypertension occurred in 27.5% of the patients with psoriasis and in 14.4% of the controls (p < 0.001). Obesity was present in 8.4% of the patients with psoriasis as opposed to 3.6% of the controls (p < 0.001). Ischemic heart disease was observed in 14.2% of the patients with psoriasis as compared to 7.1% of the controls (p < 0.001). Multivariate models adjusting for age, gender and smoking status of the patients demonstrated that psoriasis was associated with the metabolic syndrome (OR = 1.3, 95% CI = 1.1-1.4), ischemic heart disease (OR = 1.1, 95% CI = 1.0-1.2), diabetes mellitus (OR = 1.2, 95% CI = 1.0-1.3), hypertension (OR = 1.3, 95% CI = 1.2-1.5) and obesity (OR = 1.7, 95% CI = 1.5-1.9). LIMITATIONS: The study is designed as a case-control study, thus an association alone was proven and not causality. CONCLUSION: Our findings demonstrate a possible association between psoriasis and the metabolic syndrome. Appropriate treatment of the metabolic syndrome may be an important part of the management of patients with psoriasis.
18003610 Creation and X-ray structure analysis of the tumor necrosis factor receptor-1-selective mu 2008 Jan 11 Tumor necrosis factor-alpha (TNF) induces inflammatory response predominantly through the TNF receptor-1 (TNFR1). Thus, blocking the binding of TNF to TNFR1 is an important strategy for the treatment of many inflammatory diseases, such as hepatitis and rheumatoid arthritis. In this study, we identified a TNFR1-selective antagonistic mutant TNF from a phage library displaying structural human TNF variants in which each one of the six amino acid residues at the receptor-binding site (amino acids at positions 84-89) was replaced with other amino acids. Consequently, a TNFR1-selective antagonistic mutant TNF (R1antTNF), containing mutations A84S, V85T, S86T, Y87H, Q88N, and T89Q, was isolated from the library. The R1antTNF did not activate TNFR1-mediated responses, although its affinity for the TNFR1 was almost similar to that of the human wild-type TNF (wtTNF). Additionally, the R1antTNF neutralized the TNFR1-mediated bioactivity of wtTNF without influencing its TNFR2-mediated bioactivity and inhibited hepatic injury in an experimental hepatitis model. To understand the mechanism underlying the antagonistic activity of R1antTNF, we analyzed this mutant using the surface plasmon resonance spectroscopy and x-ray crystallography. Kinetic association/dissociation parameters of the R1antTNF were higher than those of the wtTNF, indicating very fast bond dissociation. Furthermore, x-ray crystallographic analysis of R1antTNF suggested that the mutation Y87H changed the binding mode from the hydrophobic to the electrostatic interaction, which may be one of the reasons why R1antTNF behaved as an antagonist. Our studies demonstrate the feasibility of generating TNF receptor subtype-specific antagonist by extensive substitution of amino acids of the wild-type ligand protein.
17346334 High mobility group box-1 protein in patients with suspected community-acquired infections 2007 INTRODUCTION: Sepsis is a serious condition with a significant morbidity and mortality. New insight into the immunopathogenesis of sepsis could promote the development of new strategies for diagnosis and therapy. High mobility group box-1 protein (HMGB1) has been known for many years as a nuclear chromosomal protein. Its role as a pro-inflammatory cytokine in sepsis and rheumatoid arthritis has been described recently. The aim of our study was to evaluate HMGB1 as a molecular marker in patients with community-acquired infections. METHODS: Patients suspected of having infections/sepsis and admitted to a department of internal medicine were included in the study in a prospective manner. Demographic data, comorbidity, routine biochemistry, microbiological data, infection focus, severity score, and mortality on day 28 were recorded. Plasma and serum were sampled at the time of admission. HMGB1 levels were measured with a commercially available enzyme-linked immunosorbent assay (ELISA). Procalcitonin levels were measured with a TRACE (time-resolved amplified cryptate emission) assay. Lipopolysaccharide-binding protein and interleukin-6 were measured with a chemiluminiscent immunometric assay. Soluble haemoglobin scavenger receptor (sCD163) levels were measured with an in-house ELISA. RESULTS: One hundred and ninety-four patients were included in the study. Levels of HMGB1 are presented as medians and interquartile ranges: healthy controls (0.77 ng/ml, 0.6 to 1.46), non-infected patients (1.54 ng/ml, 0.79 to 2.88), infected patients without systemic inflammatory response syndrome (2.41 ng/ml, 0.63 to 3.44), patients with sepsis (2.24 ng/ml, 1.30 to 3.75), and patients with severe sepsis (2.18 ng/ml, 0.91 to 3.85). In a receiver operator characteristic curve analysis discriminating between non-infected patients and all infected patients, the area under the curve for HMGB1 was 0.59 (P < 0.0001). HMGB1 correlated only weakly to levels of white blood cell count, neutrophils, C-reactive protein, interleukin-6, procalcitonin, and lipopolysaccharide-binding protein (P < 0.001). HMGB1 did not correlate to sCD163. CONCLUSION: In a cohort of patients with suspected community-acquired infections and sepsis, HMGB1 levels were statistically significantly higher in patients compared to the healthy controls. There was no statistically significant difference between the infected and the non-infected patients. Levels of HMGB1 correlated only very weakly to other pro-inflammatory markers and did not correlate to the anti-inflammatory marker sCD163.
17320132 The regulatory effect of SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-l]b 2007 Apr 15 SC-236, (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1-pyrazol-1-]benzenesulfonamide; C(16)H(11)ClF(3)N(3)O(2)S), is a highly selective cyclooxygenase (COX)-2 inhibitor. Recently, there have been reports that SC-236 protects against cartilage damage in addition to reducing inflammation and pain in osteoarthritis. However, the mechanism involved in the inflammatory allergic reaction has not been examined. Mast cells accumulation can be related to inflammatory conditions, including allergic rhinitis, asthma, and rheumatoid arthritis. The aim of the present study is to investigate the effects of SC-236 on stem cell factor (SCF)-induced migration, morphological alteration, and cytokine production of rat peritoneal mast cells (RPMCs). We observed that SCF significantly induced the migration and morphological alteration. The ability of SCF to enhance migration and morphological alteration was abolished by treatment with SC-236. In addition, production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and vascular endothelial growth factor (VEGF) production induced by SCF was significantly inhibited by treatment with SC-236. Previous work has demonstrated that SCF-induced migration and cytokine production of mast cells require p38 MAPK activation. We also showed that SC-236 suppresses the SCF-induced p38 MAPK activation in RPMCs. These data suggest that SC-236 inhibits migration and cytokine production through suppression of p38 MAPK activation. These results provided new insight into the pharmacological actions of SC-236 and its potential therapeutic role in the treatment of inflammatory allergic diseases.
17235432 On the pathway of an animal model for restless legs syndrome.. 2007 Jan Restless legs syndrome (RLS) is a chronic sleep motor disorder that affects up to 10% of the general population. Except for periodic leg movements (PLM), which can be found in the great majority of RLS patients, no objective hematochimic or neurophysiological markers are available to prove the diagnosis, which is based on clinical standard criteria. Nowadays, the aetiopathogenesis of the syndrome is unknown. In a consistent sample of patients affected by the idiopathic form, the disease is inherited as an autosomal dominant trait related to an unidentified locus, while each symptomatic form is probably linked to a specific cause. Although of possible different origins, both the primary and secondary forms may share the same pathogenetic mechanism, which, even if unclear, could be characterised by a neurological dysfunction of the dopaminergic system. Several issues, including strong efficacy of dopamine-agonist treatments, support this theory, which is currently considered the main pathogenetic hypothesis. Most of the past studies tried to clarify the RLS mechanism using the neurophysiological, biochemical and neuroimaging techniques applied to the field of human research. Now the time has come to accept the challenge in creating an animal model of RLS, which may emerge as a decisive step in understanding RLS pathogenesis, and to develop and test new therapies. Even though there have been a few significant efforts, a valid animal model of RLS still does not exist. In past pioneering studies, the authors attempted to induce restless motor behaviour in animals by different strategies: antidopaminergic pharmacological interventions, spinal or cerebral lesions of specific regions involved in the motor control and in dopamine regulation, and selective deletion of genes coding for dopamine receptors. Rodents (mice and rats) were always chosen by the authors as the animals for their experiments. The current tendency in achieving an RLS model is generally represented by simulation of a symptomatic condition of RLS or by a direct interference of the dopaminergic system. In this regard, the pharmacological method had the intention to reproduce the neuroleptic-induced acathisia, the spinal lesional model was based on the hypothesis of myelopathic- related PLM, and the hypothalamic lesion tested the motor consequence of A11 dopaminergic neurons. Preliminary studies are underway to replicate the pregnancy-related form of RLS by using a hormonal intervention, and the iron-deficiency secondary form by using specific iron-free diets. Today, modern technologies are available to easily replicate in animals most of the symptomatic RLS conditions. In addition, more than a few well validated animal models of different diseases known to be related to RLS or PLM, for instance, Parkinson's disease, rheumatoid arthritis and renal failure, could also be exploited in addressing this topic. The real obstacle in achieving an RLS model is the absence of a certain diagnostic marker to recognise if the animal that underwent the different experimental procedures has developed the RLS condition or not. Concerning this issue, possible specific endpoints are represented by the increase in locomotor activity, which are ascertainable by different techniques, such as openfield or run-wheel activity, or by sleep fragmentation, in which the circadian shift can be verified by applying polysomnography on the animal. PLM are probably the only specific and reliable markers available to recognise and quantify experimentally induced RLS. Despite a few authors who reported the presence of limb-phasic, pseudoperiodic activity during sleep in old or in lesioned rats, the existence of spontaneous or provoked PLM in animals is still debated. Eventually, the PLM features in an animal could be markedly different compared to human ones. To recognise and characterise PLM in animals, three more essential steps are required: a method to record directly, as in humans, the activity of the tibialis anterior (TA) muscles, a consistent amount of normative control data on the TA activity in healthy animals, and reliable analysis to distinguish the generic phasic muscular activity to a possible unambiguous PLM pattern. This review includes a summary and a critical discussion of the previous tentative RLS models, proposals for other possible animal models, and firstly the preliminary normative data on TA activity during sleep in normal rodents.
16686369 Breast cancer resistance protein (Bcrp/abcg2) is a major determinant of sulfasalazine abso 2006 Jan Sulfasalazine is used in the treatment of ulcerative colitis, Crohn's disease, and rheumatoid arthritis. When administered orally, sulfasalazine is poorly absorbed with an estimated bioavailability of 3-12%. Recent studies using the T-cell line (CEM) have shown that sulfasalazine is a substrate for the ATP-binding cassette (ABC) efflux pump ABCG2. ABCG2 is known to efflux a number of xenobiotics and appears to be a key determinant of efficacy and toxicity of ABCG2 substrates. To date, there has not been any systematic study on the mechanisms involved in the transport of sulfasalazine in vivo. Accordingly, we investigated whether Bcrp (abcg2) is involved in the disposition of sulfasalazine. After oral administration of 20 mg/kg sulfasalazine, the area under the plasma concentration (AUC) time profile in Bcrp1 (abcg2)-/- knockout (KO) mice was approximately 111-fold higher than that in FVB wild-type (WT) mice. After intravenous administration of 5 mg/kg sulfasalazine, the AUC in Bcrp1 (abcg2)-/- KO mice was approximately 13-fold higher than that in WT mice. Moreover, treatment of WT mice with a single oral dose of gefitinib (Iressa; 50 mg/kg), a known inhibitor of Bcrp, given 2 h prior to administering a single oral dose of sulfasalazine (20 mg/kg), resulted in a 13-fold increase in the AUC of sulfasalazine compared to the AUC in vehicle-treated mice. Since gefitinib is also an inhibitor of P-glycoprotein (P-gp), the impact of P-gp on sulfasalazine absorption in vivo was also examined. The sulfasalazine AUC in mdr1a-/- KO versus WT mice did not differ significantly after either an oral (20 mg/kg) or an intravenous dose (5 mg/kg). We conclude that Bcrp (abcg2) is an important determinant for the oral bioavailability and the elimination of sulfasalazine in the mouse, and that sulfasalazine has the potential to be utilized as a specific in vivo probe of Bcrp (abcg2).
16133077 Can povidone-iodine solution be used safely in a spinal surgery? 2006 Jun Intra-operative incidental contamination of surgical wounds is not rare. Povidone-iodine solution can be used to disinfect surgical wounds. Although povidone-iodine is a good broad-spectrum disinfecting agent, it has occasionally been reported to have a negative effect on wound healing and bone union. Therefore, its safety in a spinal surgery is unclear. A prospective, single-blinded, randomized study was accordingly conducted to evaluate the safety of povidone-iodine solution in spinal surgeries. Ascertained herein was the effect of wound irrigation with diluted povidone-iodine solution on wound healing, infection rate, fusion status and clinical outcome of spinal surgeries. MATERIALS AND METHODS: From January 2002 to August 2003, 244 consecutive cases undergoing primary instrumented lumbosacral posterolateral fusion due to degenerative spinal disorder with segmental instability had been collected and randomly divided into two groups: the study group (120 cases, 212 fusion levels) and the control group (124 cases, 223 fusion levels). Excluded were those patients with a prior spinal surgery, spinal trauma, malignant tumor, infectious spondylitis, rheumatoid arthritis, ankylosing spondylitis, metabolic bone disease, skeletal immaturity or with an immunosuppressive treatment. In the former group, wounds were irrigated with 0.35% povidone-iodine solution followed by normal saline solution just before the bone-grafting and instrumentation procedure. However, only with normal saline solution in the latter. All the operations were done by the same surgeon with a standard technique. All the patients were treated in the same postoperative fashion as well. Later on, wound healing, infection rate, spinal bone fusion and clinical outcome were evaluated in both groups. RESULTS: A significant improvement of back and leg pain scores, modified Japanese Orthopedic Association function scores (JOA) and ambulatory capacity have been observed in both groups. One hundred and seven patients in the study group and one hundred and nine in the control group achieved solid union. There was no infection in the study group but six deep infections in the control group. Wound dehiscence was noted in one group 1 and two group 2 patients. A subsequent statistical analysis revealed higher infection rate in the control group (P<0.05), but no significant difference in fusion rate, wound healing, improvement of pain score, function score and ambulatory capacity between the two groups. CONCLUSION: Diluted povidone-iodine solution can be used safely in spinal surgeries, and it will not influence wound healing, bone union and clinical outcome.
20641655 (111)In-Diethylenetriaminepentaacetic acid-benzyl-succinamido-Lys-IRDye800-c(Arg-Gly-Asp-D 2004 Optical fluorescence imaging is increasingly being used to monitor biological functions of specific targets in small animals (1-3). However, the intrinsic fluorescence of biomolecules poses a problem when fluorophores that absorb visible light (350–700 nm) are used. Near-infrared (NIR) fluorescence (700–1,000 nm) detection avoids the natural background fluorescence interference of biomolecules, providing a high contrast between target and background tissues in small animals. NIR fluorophores have a wider dynamic range and minimal background fluorescence as a result of reduced scattering compared with visible fluorescence detection. NIR fluorophores also have high sensitivity, attributable to low background fluorescence, and high extinction coefficients, which provide high quantum yields. The NIR region is also compatible with solid-state optical components, such as diode lasers and silicon detectors. NIR fluorescence imaging is a non-invasive alternative to radionuclide imaging in small animals (4, 5). Integrins are a family of heterodimeric glycoproteins on cell surfaces that mediate diverse biological events involving cell–cell and cell–matrix interactions (6). Integrins consist of an α and a β subunit, and they are important for cell adhesion and signal transduction. The α(v)β(3) integrin is the most prominent receptor affecting tumor growth, tumor invasiveness, metastasis, tumor-induced angiogenesis, inflammation, osteoporosis, and rheumatoid arthritis (7-12). Expression of the α(v)β(3) integrin is strong on tumor cells and activated endothelial cells, whereas expression is weak on resting endothelial cells and most normal tissues. Antagonists of α(v)β(3) are being studied as antitumor and antiangiogenic agents and its agonists are being studied as angiogenic agents for coronary angiogenesis (11, 13, 14). A peptide sequence consisting of Arg-Gly-Asp (RGD) has been identified as a recognition motif used by extracellular matrix proteins (vitronectin, fibrinogen, laminin, and collagen) to bind to a variety of integrins, including α(v)β(3). Various radiolabeled antagonists have been introduced for tumor imaging and tumor angiogenesis (15). Most of the cyclic RGD peptides are composed of five amino acids. Haubner et al. (16) reported that various cyclic RGD peptides exhibit selective inhibition of binding to α(v)β(3) (50% inhibition concentration (IC(50)), 7–40 nM) but not to α(v)β(5) (IC(50), 600–4,000 nM) or α(IIb)β(3) (IC(50), 700–5,000 nM) integrins. Various radiolabeled cyclic RGD peptides have been found to have high accumulation in tumors in nude mice (17). Li et al. (18) reported the development of (111)In-DTPA-Bz-SA-Lys-IRDye800-c(RGDfK), a multimodality imaging agent for imaging α(v)β(3) expression on breast tumors; single-photon emission computed tomography (SPECT) imaging used (111)In-DTPA-Bz-SA and NIR imaging used IRDye800.
19008314 Tumor necrosis factor-related apoptosis-inducing ligand inhibits experimental autoimmune t 2009 Apr There have been several reports that TNF-related apoptosis-inducing ligand (TRAIL) has the ability to suppress the development of experimental autoimmune diseases, including a mouse model of experimental autoimmune encephalomyelitis, a rabbit model of rheumatoid arthritis, type 1 diabetes mellitus, in mice and experimental autoimmune thyroiditis (EAT) in mice. However, the mechanism underlying TRAIL effect is not well defined. In the present study, we specifically examined TRAIL effects on CD4(+)CD25(+) regulatory T cells. CD4(+)CD25(+) T cells prepared from mouse thyroglobulin (mTg)-immunized CBA/J mice proliferate in the presence of TRAIL and dendritic cells in vitro. These CD4(+)CD25(+) T cells included both CD4(+)CD25(+)CD45RB(Low) (regulatory) and CD4(+)CD25(+)CD45RB(High) (effector) T cells. Our results demonstrated that mTg-immunized mice treated with TRAIL showed significant increases in the number of CD4(+)CD25(+)CD45RB(Low) T cells compared with mice immunized with mTg alone. CD4(+)CD25(+)CD45RB(Low) T cells expressed much higher levels of the forkhead family transcription factor, IL-10, and TGFbeta1 than CD4(+)CD25(+)CD45RB(High) T cells, and these cells can completely suppress the proliferation of the mTg-primed splenocytes in lower concentrations than the unfractionated CD4(+)CD25(+) T cells. Furthermore, transfer of these cells into CBA/J mice prior to mTg-primed splenocyte injection could markedly reduce the frequency and severity of EAT development. CD4(+)CD25(+)CD45RB(Low) T cells were more effective at suppressing histological thyroiditis than unfractionated cells. These results indicated that TRAIL can increase the number of mTg-specific CD4(+)CD25(+)CD45RB(Low) T cells, inhibiting autoimmune responses and preventing the progression of EAT. These findings reveal a novel mechanism by which TRAIL could inhibit autoimmune disease.
20641690 (64)Cu-1,4,7,10-Tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-polyethylene-glycol-s 2004 Optical fluorescence imaging is increasingly used to visualize biological functions of specific targets (1, 2). However, the intrinsic fluorescence of biomolecules poses a problem when fluorophores that absorb visible light (350–700 nm) are used. Near-infrared (NIR) fluorescence (700–1,000 nm) detection avoids the background fluorescence interference of natural biomolecules, providing a high contrast between target and background tissues. NIR fluorophores have wider dynamic range and minimal background as a result of reduced scattering compared with visible fluorescence detection. They also have high sensitivity, resulting from low infrared background, and high extinction coefficients, which provide high quantum yields. The NIR region is also compatible with solid-state optical components, such as diode lasers and silicon detectors. NIR fluorescence imaging is becoming a non-invasive alternative to radionuclide imaging in small animals. Carbon nanotubes are made of carbon fullerene carbon units, which respond to local dielectric changes without photobleaching (3, 4). They can be tuned in a range of wavelengths for NIR absorption, thus providing broad excitation profiles and high absorption coefficients. They can be coated and capped with hydrophilic materials for additional conjugation with biomolecules, such as peptides, antibodies, nucleic acids, and small organic compounds for in vitro and in vivo studies (5). Single-walled carbon nanotubes (SWNTs) have a diameter of 1–5 nm and a length of 200–1,000 nm, and they have been shown to be non-toxic to cells in vitro (6). However, there have been limited in vivo studies of SWNT toxicological and pharmacological profiles in small animals. Integrins are a family of heterodimeric glycoproteins on cell surfaces that mediate diverse biological events involving cell–cell and cell–matrix interactions (7). Integrins consist of an α and a β subunit and are important for cell adhesion and signal transduction. The α(v)β(3) integrin is the most prominent receptor affecting tumor growth, tumor invasiveness, metastasis, tumor-induced angiogenesis, inflammation, osteoporosis, and rheumatoid arthritis (8-13). Expression of the α(v)β(3) integrin is strong in tumor cells and activated endothelial cells, whereas expression is weak in resting endothelial cells and most normal tissues. Antagonists of α(v)β(3) are being studied as antitumor and antiangiogenic agents and the agonists of α(v)β(3) are being studied as angiogenic agents for coronary angiogenesis (12, 14, 15). A peptide sequence consisting of Arg-Gly-Asp (RGD) has been identified as a recognition motif used by extracellular matrix proteins (vitronectin, fibrinogen, laminin, and collagen) to bind to a variety of integrins, including α(v)β(3). Various ligands have been introduced for imaging of tumors and tumor angiogenesis (16). Liu et al. (17) conjugated (64)Cu-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid ((64)Cu-DOTA) and c(RGDyK) to phospholipid-polyethylene-glycol (PL-PEG)–coated SWNTs ((64)Cu-DOTA-SWNT-PEG-c(RGDyK)) for imaging α(v)β(3) integrin expression in tumors and their vasculatures.
18823986 Lower gastrointestinal events in a double-blind trial of the cyclo-oxygenase-2 selective i 2008 Nov BACKGROUND & AIMS: Nonsteroidal anti-inflammatory drugs (NSAIDs) cause lower gastrointestinal (GI) clinical events such as bleeding. Cyclo-oxygenase (COX)-2 selective inhibitors decrease upper GI events, but no prospective trial has prespecified assessment of lower GI clinical events. METHODS: Patients >or=50 years old with osteoarthritis or rheumatoid arthritis were randomly assigned to etoricoxib (60 or 90 mg qd) or diclofenac (150 mg qd). Lower GI clinical events, confirmed by a blinded adjudication committee, included perforation or obstruction requiring hospitalization or bleeding (gross or occult rectal bleeding without upper GI cause associated with hypotension, orthostatic changes in heart rate [>20 beats per minute] or blood pressure [>20 mmHg systolic or >10 mmHg diastolic], hemoglobin drop >or=2 g/dl, or transfusion; or observed active bleeding or stigmata of hemorrhage). RESULTS: We enrolled 34,701 patients with mean duration of therapy of 18 months. Rates were 0.32 and 0.38 lower GI clinical events per 100 patient-years for etoricoxib and diclofenac (hazard ratio [HR] = 0.84; 95% confidence interval [CI], 0.63-1.13). Bleeding was the most common event (rates of 0.19 and 0.23 per 100 patient-years, respectively). Multivariable analysis revealed significant risk factors to be prior lower GI event (HR = 4.06; 95% CI, 2.93-5.62) and age >or=65 years (HR = 1.98; 95% CI, 1.45-2.71). CONCLUSIONS: A statistically significant decrease in lower GI clinical events was not seen with the COX-2 selective inhibitor etoricoxib versus the traditional NSAID diclofenac. The risk of a lower GI clinical event with NSAID use seems to be constant over time, and the major risk factors are a prior lower GI event and older age.
18537718 Small molecule inhibitors of Lck: the search for specificity within a kinase family. 2008 Jun The Src family of non-transmembrane protein kinases is comprised of eleven homologous members in mammals. Together, these kinases regulate a wide variety of cellular processes including cell survival, proliferation, differentiation, and motility. One member of this family, Lck, plays a pivotal role in T-cell signaling. Inhibition of Lck with small molecules has significant potential for therapeutic immunosuppression and treatment of diseases such as rheumatoid arthritis and asthma. Critical for successful clinical use of any Lck inhibitor is high specificity for Lck as inhibition of other members of the Src kinase family may result in unwanted side effects. In this review we provide an overview of the various synthetic compounds currently under investigation as Lck-specific inhibitors. In addition we provide an analysis of the properties of these compounds that account for the specificity required for the inhibition of one of eleven highly similar kinases.
18417150 Simple and highly sensitive assay system for TNFR2-mediated soluble- and transmembrane-TNF 2008 Jun 1 Drugs that target tumor necrosis factor-alpha (TNF) are particularly important in the treatment of severe inflammatory progression in rheumatoid arthritis, Crohn's disease and psoriasis. Despite the central role of the TNF/TNF receptor (TNFR) in various disease states, there is a paucity of information concerning TNFR2 signaling. In this study, we have developed a simple and highly sensitive cell-death based assay system for analyzing TNFR2-mediated bioactivity that can be used to screen for TNFR2-selective drugs. Using a lentiviral vector, a chimeric receptor was engineered from the extracellular and transmembrane domain of human TNFR2 and the intracellular domain of mouse Fas and the recombinant protein was then expressed in TNFR1(-/-)R2(-/-) mouse preadipocytes. Our results demonstrate that this chimeric receptor is capable of inducing apoptosis by transmembrane- as well as soluble-TNF stimuli. Moreover, we found that our bioassay based on cell death phenotype had an approximately 80-fold higher sensitivity over existing bioassays. We believe our assay system will be an invaluable research tool for studying TNFR2 and for screening TNFR2-targeted drugs.
18098289 Induction of colitis and rapid development of colorectal tumors in mice deficient in the n 2008 Apr 15 Pituitary adenylyl cyclase activating peptide (PACAP) is expressed in central, sensory, autonomic, and enteric neurons. Although it classically acts as a neurotransmitter/neuromodulator, recent studies indicate that PACAP can also regulate immune function. To this effect, PACAP has been shown to reduce clinical symptoms and inflammation in mouse models of human immune-based diseases such as rheumatoid arthritis, Crohn's Disease, septic shock and multiple sclerosis. Despite these findings, the role of the endogenous peptide in regulating immune function is unknown. To determine if endogenous PACAP plays a protective role in inflammatory bowel disease (IBD) and IBD-associated colorectal cancer in mice, PACAP-deficient (KO) mice were subjected to 3 cycles of dextran sulfate sodium (DSS) in drinking water over 2 months, an established mouse model for colitis. Compared to wild type (WT) controls, PACAP KO mice exhibited more severe clinical symptoms of colitis and had significantly higher colonic inflammation on pathological examination. Moreover, 60% of the PACAP KO mice developed colorectal tumors with an aggressive-appearing pathology. Consistent with published data, DSS-treated WT mice did not develop such tumors. The results demonstrate a new mouse model which rapidly develops inflammation-associated colorectal cancer in the absence of a carcinogen.
18062909 Thrombin-induced IL-6 production in human synovial fibroblasts is mediated by PAR1, phosph 2008 Mar Thrombin is a key factor in the stimulation of fibrin deposition, angiogenesis and proinflammatory processes. Abnormalities in these processes are primary features of rheumatoid arthritis (RA) in synovial tissues. We investigated the signaling pathway involved in IL-6 production caused by thrombin in synovial fibroblasts. Thrombin caused concentration- and time-dependent increases in IL-6 production. By using pharmacological inhibitors or activators or genetic inhibition by the protease activated receptor (PAR), siRNA revealed that the PAR1 receptor but not other PAR receptors is involved in thrombin-mediated up-regulation of IL-6. Thrombin-mediated IL-6 production was attenuated by thrombin inhibitor (PPACK), phospholipase C inhibitor (U73122), protein kinase C alpha inhibitor (Ro320432), Src inhibitor (PP2), NF-kappaB inhibitor (PDTC), I kappa B protease inhibitor (TPCK), or NF-kappaB inhibitor peptide. Stimulation of synovial fibroblasts with thrombin activated I kappa B kinase alpha/beta (IKK alpha/beta), I kappa B alpha phosphorylation, I kappa B alpha degradation, p65 phosphorylation at Ser(276), p65 and p50 translocation from the cytosol to the nucleus, and kappaB-luciferase activity. Thrombin-mediated an increase of IKK alpha/beta activity, kappaB-luciferase activity and p65 and p50 binding to the NF-kappaB element was inhibited by PPACK, U73122, Ro320432 and PP2. The binding of p65 and p50 to the NF-kappaB elements, as well as the recruitment of p300 and the enhancement of p50 acetylation on the IL-6 promoter was enhanced by thrombin. Our results suggest that thrombin increased IL-6 production in synovial fibroblasts via the PAR1 receptor/PI-PLC/PKC alpha/c-Src/NF-kappaB and p300 signaling pathway.
17626792 RGS10-null mutation impairs osteoclast differentiation resulting from the loss of [Ca2+]i 2007 Jul 15 Increased osteoclastic resorption leads to many bone diseases, including osteoporosis and rheumatoid arthritis. While rapid progress has been made in characterizing osteoclast differentiation signaling pathways, how receptor activator of nuclear factor kappaB (NF-kappaB) ligand (RANKL) evokes essential [Ca2+]i oscillation signaling remains unknown. Here, we characterized RANKL-induced signaling proteins and found regulator of G-protein signaling 10 (RGS10) is predominantly expressed in osteoclasts. We generated RGS10-deficient (RGS10-/-) mice that exhibited severe osteopetrosis and impaired osteoclast differentiation. Our data demonstrated that ectopic expression of RGS10 dramatically increased the sensitivity of osteoclast differentiation to RANKL signaling; the deficiency of RGS10 resulted in the absence of [Ca2+]i oscillations and loss of NFATc1; ectopic NFATc1 expression rescues impaired osteoclast differentiation from deletion of RGS10; phosphatidylinositol 3,4,5-trisphosphate (PIP3) is essential to PLCgamma activation; and RGS10 competitively interacts with Ca2+/calmodulin and PIP3 in a [Ca2+]i-dependent manner to mediate PLCgamma activation and [Ca2+]i oscillations. Our results revealed a mechanism through which RGS10 specifically regulates the RANKL-evoked RGS10/calmodulin-[Ca2+]i oscillation-calcineurin-NFATc1 signaling pathway in osteoclast differentiation using an in vivo model. RGS10 provides a potential therapeutic target for the treatment of bone diseases.
17244154 Reduced CCR4, interleukin-13 and GATA-3 up-regulation in response to type 2 cytokines of c 2007 Jun Aberrancies in T-cell polarization including expression of chemokine receptors have been reported in human leucocyte antigen (HLA) class II associated autoimmune diseases, such as type 1 diabetes (T1D) and rheumatoid arthritis. We asked whether these aberrancies are present at birth in newborn infants carrying the HLA risk haplotypes for T1D. Sixty-seven cord blood (CB) samples from infants were screened for T1D-associated HLA risk genotypes (HLA-DR4-DQ8 and/or DR3-DQ2 without protective alleles). CB lymphocytes were stimulated with phytohaemagglutinin in type 1 (interleukin (IL)-12, anti-IL4) or type 2 (IL-4, anti-IL12) cytokine environment for 6 days. The expression of chemokine and cytokine receptors on T cells was determined by flow cytometry, secretion of cytokines was analysed with enzyme-linked immunosorbent assay, and transcription factors were analysed using real-time reverse transcriptase-polymerase chain reaction. After culture of CB lymphocytes in type 2 cytokine environment newborn infants carrying DR4-DQ8 haplotype (n=18) showed reduced percentage of CD4 T cells expressing CCR4 (P=0 x 009) and the level of CCR4 mRNA was decreased (P=0 x 008). In addition, lower secretion of IL-13 and expression of GATA-3 in CB lymphocytes cultured in type 2 cytokine environment were found in the infants with DR4-DQ8 haplotype (P=0 x 020 and P=0 x 004, respectively) in comparison to newborn infants without DR4-DQ8 and DR3-DQ2 haplotypes (n=37). Poor in vitro induction of type 2 immune responses in newborn infants with DR4-DQ8 haplotype suggests that the HLA genotype associated with risk of autoimmunity may affect the T cell polarization already at birth, which in turn may contribute to the risk for autoimmunity later in life.
16565497 Type I interferon production by tertiary lymphoid tissue developing in response to 2,6,10, 2006 Apr Lymphoid neogenesis is associated with antibody-mediated autoimmune diseases such as Sjogren's syndrome and rheumatoid arthritis. Although systemic lupus erythematosus is the prototypical B-cell-mediated autoimmune disease, the role of lymphoid neogenesis in its pathogenesis is unknown. Intraperitoneal injection of 2,6,10,14-tetramethyl-pentadecane (TMPD, pristane) or mineral oil causes lipogranuloma formation in mice, but only TMPD-treated mice develop lupus. We report that lipogranulomas are a form of lymphoid neogenesis. Immunoperoxidase staining of lipogranulomas revealed B cells, CD4(+) T cells, and dendritic cells and in some cases organization into T- and B-cell zones. Lipogranulomas also expressed the lymphoid chemokines CCL21, CCL19, CXCL13, CXCL12, and CCL22. Expression of the type I interferon (IFN-I)-inducible genes Mx1, IRF7, IP-10, and ISG-15 was greatly increased in TMPD- versus mineral oil-induced lipogranulomas. Dendritic cells from TMPD lipogranulomas underwent activation/maturation with high CD86 and interleukin-12 expression. Magnetic bead depletion of dendritic cells markedly diminished IFN-inducible gene (Mx1) expression. We conclude that TMPD-induced lupus is associated with the formation of ectopic lymphoid tissue containing activated dendritic cells producing IFN-I and interleukin-12. In view of the increased IFN-I production in systemic lupus erythematosus, these studies suggest that IFN-I from ectopic lymphoid tissue could play a role in the pathogenesis of experimental lupus in mice.
16542377 Increased expression and secretion of interleukin-6 in human parvovirus B19 non-structural 2006 Apr Human parvovirus B19 (B19) has been associated with a variety of autoimmune diseases, including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We have demonstrated previously that B19 non-structural protein (NS1) induced apoptosis through the mitochondria cell death pathway in COS-7 epithelial cells and that B19 NS1 may play a role in the pathogenesis of autoimmune diseases. In order to examine the expression profiles of cytokines and chemokines in B19 NS1 transfected COS-7 cells, we constructed the NS1 gene in the pEGFP-C1 vector named enhanced green fluorescence protein gene (EGFP)-NS1. COS-7 cells were transfected with EGFP or EGFP-NS1 plasmid. The expression profiles of cytokines and chemokines, including interleukin (IL)-1beta, IL-5, IL-6, IL-8, IL-10, tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, granulocyte-macrophage colony-stimulating factor (GM-CSF), growth-related oncogene alpha (GROalpha), interferon gamma-inducible protein (IP)-10, stromal cell derived factor (SDF)-1, macrophage inflammatory protein (MIP)-1beta, monocyte chemoattractant protein (MCP)-1, regulated upon activation normal T cell expressed and secreted (RANTES), Fractalkine, CX3CR1, CCR2, CCR5 and CCR11 were examined in COS-7 cells, EGFP and EGFP-NS1 transfected cells using enzyme-linked immunosorbent assay (ELISA) or reverse transcription-polymerase chain reaction (RT-PCR). Increased expression and levels of IL-6 were found in EGFP-NS1 transfected cells using RT-PCR and ELISA. There were no significant increases in the expression of IL-1beta, IL-8, IP-10, SDF-1, RANTES, Fractalkine, CX3CR-1, CCR2, CCR5, CCR11, TNF-alpha, GM-CSF and TGF-beta using RT-PCR. There were no significantly increased levels of IL-5, IL-10, TNF-alpha, TGF-beta, GROalpha, MIP-1beta and MCP-1 found by ELISA in this study. Our results show that increased expression and secretion of IL-6 in B19 NS1 transfected epithelial cells may play a role in the pathogenesis of autoimmune diseases.