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ID PMID Title PublicationDate abstract
19719969 Antiangiogenic effect of celastrol on the growth of human glioma: an in vitro and in vivo 2009 Jul 20 BACKGROUND: Celastrol is a major active component of Tripterygium wilfordii named "Thunder God Vine", which is widely used to treat rheumatoid arthritis in China. The present study aims to demonstrate that celastrol has potent anticancer activity against glioma in vitro and in vivo. METHODS: Proliferation, migration, and tube formation of ECV-304 cells were determined by MTT and matrigel assays. The antiangiogenesis effect of celastrol was assessed by the chick chorioallantoic membrane assay and the in vivo matrigel plug assay. Tumor microvessels (MVD) were determined immunohistochemically with anti-CD34 antibody. Vascular endothelial growth factor (VEGF) expression was defined as positive if distinct staining of the cytoplasm was observed in at least 10% of tumor cells at the deepest invasive site, central portion and superficial part of the tumor. MVD was estimated by averaging the counts of three times at a x 200 field in the most vascularized area of the deepest invasive site. RESULTS: Celastrol purified from T. wilfordii inhibited the proliferation of vascular endothelial cells (ECV-304) with an IC50 value of 1.33 microg/ml. Celastrol, at the concentration of 0.2 microg/ml, significantly inhibited cell migration and tube formation. Celastrol inhibited angiogenesis in a dose-dependent manner both in vitro and in vivo. Subcutaneous administration of celastrol 5 days a week for 4 consecutive weeks significantly reduced tumor volume in a dose-dependent manner in the SHG-44 xenograft model. Celastrol at each different dose level lowered the density of MVD significantly in tumor bearing nude mice compared to the control group. Immunohistochemistry experiments further revealed that celastrol also decreased the level of VEGFR-1 and VEGFR-2 expression, but not the level of VEGF expression. CONCLUSIONS: Celastrol elicits antiangiogenic effects in vitro and in vivo, and could be of potential use in the treatment of malignant cancers such as glioblastoma.
19302812 TNF-alpha and IL-1beta inhibit RUNX2 and collagen expression but increase alkaline phospha 2009 Apr 10 AIMS: Joint inflammation leads to bone erosion in rheumatoid arthritis (RA), whereas it induces new bone formation in spondyloarthropathies (SpAs). Our aims were to clarify the effects of tumour necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta) on osteoblast differentiation and mineralization in human mesenchymal stem cells (MSCs). MAIN METHODS: In MSCs, expression of osteoblast markers was assessed by real-time PCR and ELISA. Activity of tissue-nonspecific alkaline phosphatase (TNAP) and mineralization were determined by the method of Lowry and alizarin red staining respectively. Involvement of RUNX2 in cytokine effects was investigated in osteoblast-like cells transfected with a dominant negative construct. KEY FINDINGS: TNF-alpha (from 0.1 to 10 ng/ml) and IL-1beta (from 0.1 to 1 ng/ml) stimulated TNAP activity and mineralization in MSCs. Addition of 50 ng/ml of IL-1 receptor antagonist in TNF-alpha-treated cultures did not reverse TNF-alpha effects, indicating that IL-1 was not involved in TNF-alpha-stimulated TNAP activity. Both TNF-alpha and IL-1beta decreased RUNX2 expression and osteocalcin secretion, suggesting that RUNX2 was not involved in mineralization. This hypothesis was confirmed in osteoblast-like cells expressing a dominant negative RUNX2, in which TNAP expression and activity were not reduced. Finally, since mineralization may merely rely on increased TNAP activity in a collagen-rich tissue, we investigated cytokine effects on collagen expression, and observed that cytokines decreased collagen expression in osteoblasts from MSC cultures. SIGNIFICANCE: The different effects of cytokines on TNAP activity and collagen expression may therefore help explain why inflammation decreases bone formation in RA whereas it induces ectopic ossification from collagen-rich entheses during SpAs.
19299722 Modulation of T lymphocyte replicative senescence via TNF-{alpha} inhibition: role of casp 2009 Apr 1 Expanded populations of CD8(+) T lymphocytes lacking CD28 expression are associated with a variety of deleterious clinical outcomes, including early mortality in the elderly, more rapid progression to AIDS, cardiovascular disease, and enhanced tumor cell growth. In cell culture, irreversible loss of CD28 expression correlates with increased production of TNF-alpha as CD8(+) T cells are driven to the nonproliferative end stage of replicative senescence by multiple rounds of Ag-driven cell division. Interestingly, in patients with rheumatoid arthritis, inhibition or neutralization of TNF-alpha reduces the proportion of T cells lacking CD28 in the disease joints, consistent with studies showing a direct involvement of this cytokine in CD28 gene transcription. Here, we show that modulation of TNF-alpha levels in long-term cultures of human CD8(+) T lymphocytes, by chronic exposure either to a neutralizing Ab or to an inhibitor of the TNF-alpha receptor-1, increases proliferative potential, delays loss of CD28 expression, retards cytokine profile changes, and enhances telomerase activity. We also show that constitutive caspase-3, one of the downstream effectors of TNF-alphaR1 binding, increases in parallel with the loss of CD28 in long-term cultures, but this effect is blunted in the presence of the TNF-alpha inhibitors. Consistent with the in vitro culture data, CD8(+)CD28(-) T lymphocytes tested immediately ex vivo also show significantly higher levels of caspase-3 compared with their CD28(+) counterparts. These findings help elucidate the complex nature of CD28 gene regulation, and may ultimately lead to novel therapeutic approaches for diseases associated with increased proportions of CD28(-) T lymphocytes.
19176759 Vascular endothelial growth factor induces protein kinase D-dependent production of proinf 2009 Apr Emerging evidence indicates that vascular endothelial growth factor (VEGF) plays a critical role in host inflammatory responses in several disease states, including atherosclerosis, sepsis, and rheumatoid arthritis. In this study, we determined the effect of VEGF on endothelial induction of proinflammatory cytokines and investigated the responsible signal pathways. By using a cytokine antibody array that detects the end point protein products released from endothelial cells (ECs), we found that VEGF, via VEGF receptor 2 (VEGFR2), predominantly induced the production of proinflammatory cytokine interleukin (IL)-6 and CXC chemokines IL-8 and growth-related oncogene-alpha (GRO-alpha) in ECs but not in leukocytes among 36 cytokines in the array. The production of these inflammatory cytokines by VEGF was much stronger than the induction of cell adhesion molecule in ECs. We further found that the cytokine production by VEGF was essentially mediated by the Gö-6976-sensitive protein kinase D (PKD) family kinases. Importantly, the VEGF-induced production of IL-6, IL-8, and GRO-alpha was inhibited approximately 70%, 40%, or 37% by PKD1 silencing (more than 90% knockdown) with three small interference RNAs that target different PKD1 regions. Moreover, silencing PKD2 downregulated VEGFR2 and markedly inhibited the cytokine production by VEGF in ECs. Our results indicate that VEGF, via VEGFR2-PKD1 axis, induces the production of proinflammatory cytokine IL-6, IL-8, and GRO-alpha in ECs but not in leukocytes, which may offer new insights into the mechanism of the proinflammatory activity of VEGF.
19103878 Functional anergy in a subpopulation of naive B cells from healthy humans that express aut 2009 Jan 16 Self-reactive B cells not controlled by receptor editing or clonal deletion may become anergic. We report that fully mature human B cells negative for surface IgM and retaining only IgD are autoreactive and functionally attenuated (referred to as naive IgD(+)IgM(-) B cells [B(ND)]). These B(ND) cells typically make up 2.5% of B cells in the peripheral blood, have antibody variable region genes in germline (unmutated) configuration, and, by all current measures, are fully mature. Analysis of 95 recombinant antibodies expressed from the variable genes of single B(ND) cells demonstrated that they are predominantly autoreactive, binding to HEp-2 cell antigens and DNA. Upon B cell receptor cross-linkage, B(ND) cells have a reduced capacity to mobilize intracellular calcium or phosphorylate tyrosines, demonstrating that they are anergic. However, intense stimulation causes B(ND) cells to fully respond, suggesting that these cells could be the precursors of autoantibody secreting plasma cells in autoimmune diseases such as systemic lupus erythematosus or rheumatoid arthritis. This is the first identification of a distinct mature human B cell subset that is naturally autoreactive and controlled by the tolerizing mechanism of functional anergy.
20848524 Association of FcgR2a, but not FcgR3a, with inflammatory bowel diseases across three Cauca 2010 Dec BACKGROUND: The Fc receptors II and III (FcgR2a, and FcgR3a) play a crucial role in the regulation of the immune response. The FcgR2a*519GG and FcgR3a*559CC genotypes have been associated with several autoimmune diseases including systemic lupus erythematosus, rheumatoid arthritis, nephritis, and possibly to type I diabetes, and celiac disease. In a large multicenter, two-stage study of 6570 people, we tested whether the FcgR2a and FcgR3a genes were also involved in inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC). METHODS: We genotyped the FcgR2a*A519G and FcgR3a*A559C functional variants in 4205 IBD patients in six well-phenotyped Caucasian IBD cohorts and 2365 ethnically matched controls recruited from the Netherlands, Spain, and New Zealand. RESULTS: In the initial Dutch study we found a significant association of FcgR2a genotypes with IBD (P-genotype = 0.02); while the FcgR2a*519GG was more common in controls (23%) than in IBD patients (18%; odds ratio [OR] = 0.75; 95% confidence interval [CI] 0.61-0.92; P = 0.004). This association was corroborated by a combined analysis across all the study populations (Mantel-Haenszel [MH] OR = 0.84; 0.74-0.95; P = 0.005) in the next stage. The Fcgr2a*GG genotype was associated with both UC (MH-OR = 0.84; 0.72-0.97; P = 0.01) and CD (MH-OR = 0.84; 0.73-0.97; P = 0.01), suggesting that this genotype confers a protective effect against IBD. There was no association of FcgR3a*A559C genotypes with IBD, CD, or UC in any of the three studied populations. CONCLUSIONS: The FcgR2a*519G functional variant was associated with IBD and reduced susceptibility to UC and to CD in Caucasians. There was no association between FcgR3a*5A559C and IBD, CD or UC.
20722907 Isolation and identification of antioxidant compounds from Ligularia fischeri. 2010 Aug 1 The plant Ligularia fischeri var. spiciformis Nakai, a well-known edible medicinal herb in Korea, has been used to treat maladies such as jaundice, scarlet fever, rheumatoid arthritis, and hepatic function failure. In this research, 4 major antioxidant compounds were detected from this plant's leaves using an on-line high-performance liquid chromatography (HPLC)-ABTS screening system, which can determine the antioxidant activity based on a decrease in absorbance at 734 nm after postcolumn reaction of HPLC-separated antioxidants with the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radicals (ABTS(*)). In order to isolate these active compounds, a preparative HPLC was applied and their chemical structures were identified as 5-O-caffeoylquinic acid (5-CQA), 3,4-di-O-caffeoylquinic acid (3,4-DCQA), 3,5-di-O-caffeoylquinic acid (3,5-DCQA), and 4,5-di-O-caffeoylquinic acid (4,5-DCQA) by ESI/MS(n) and (1)H NMR. These 4 isomers comprised over 10% of the dried leaves, with 3,5-DCQA being the most abundant compound. The radical scavenging activity of each isomer was also evaluated simultaneously through the on-line HPLC-ABTS method, which showed 94% antioxidant activity of the ethanol extract derived from caffeoylquinic acids. Among these isomers, 3,4-DCQA contained the most strong antioxidant activity while 3,5-DCQA accounted for the highest radical scavenging capacity due to having the highest content.
20521013 Leukotrienes are not essential for the efficacy of a heterologous vaccine against Mycobact 2010 Jul Leukotrienes are reported to be potent proinflammatory mediators that play a role in the development of several inflammatory diseases such as asthma, rheumatoid arthritis and periodontal disease. Leukotrienes have also been associated with protection against infectious diseases. However, the role of leukotrienes in Mycobacterium tuberculosis infection is not understood. To answer this question, we studied the role of leukotrienes in the protective immune response conferred by prime-boost heterologous immunization against tuberculosis. We immunized BALB/c mice (4-11/group) with subcutaneous BCG vaccine (1 x 10(5) M. bovis BCG) (prime) followed by intramuscular DNA-HSP65 vaccine (100 microg) (boost). During the 30 days following the challenge, the animals were treated by gavage daily with MK-886 (5 mg x kg(-1) x day(-1)) to inhibit leukotriene synthesis. We showed that MK-886-treated mice were more susceptible to M. tuberculosis infection by counting the number of M. tuberculosis colony-forming units in lungs. The histopathological analysis showed an impaired influx of leukocytes to the lungs of MK-886-treated mice after infection, confirming the involvement of leukotrienes in the protective immune response against experimental tuberculosis. However, prime-boost-immunized mice treated with MK-886 remained protected after challenge with M. tuberculosis, suggesting that leukotrienes are not required for the protective effect elicited by immunization. Protection against M. tuberculosis challenge achieved by prime-boost immunization in the absence of leukotrienes was accompanied by an increase in IL-17 production in the lungs of these animals, as measured by ELISA. Therefore, these data suggest that the production of IL-17 in MK-886-treated, immunized mice could contribute to the generation of a protective immune response after infection with M. tuberculosis.
20513989 Early results of total knee arthroplasty performed through the midvastus approach. 2010 OBJECTIVES: The aim of this study was to evaluate the early results of total knee arthroplasty (TKA) performed through the midvastus approach. METHODS: This retrospective study included 48 knees of 42 patients (29 females, 13 males; mean age 69 years; range 54 to 82 years) who underwent TKA for grade 4 knee osteoarthritis. All TKA operations were performed by the same orthopedic surgeon through the midvastus approach. Preoperatively, 40 patients (95.2%) had primary osteoarthritis, and two patients (4.8%) had rheumatoid arthritis. In all cases, a posterior stabilized cemented prosthesis with a fixed insert was used. Patellar resurfacing was performed in seven knees (14.6%). All the knees were rated according to the Knee Society knee and function scores before surgery and at the final follow-up. Postoperative radiographic evaluations were performed on anteroposterior and lateral radiographs according to the Knee Society TKA Roentgenographic Evaluation and Scoring System. The mean follow-up period was 26 months (range 12 to 49 months). RESULTS: The mean knee score significantly improved from 49.0+/-9.3 preoperatively to 87.5+/-9.9 postoperatively (p=0.000). The corresponding increase in the knee function score was from 48.8+/-9.9 to 79.6+/-14.0 (p=0.000). The mean increases in the knee and function scores were 38.5 and 30.8 points, respectively. The knee and function scores were excellent or good in 46 knees (95.8%) and 42 knees (87.5%), respectively. The mean knee flexion significantly increased by 28.6 degrees , from 84.3+/-14.7 degrees preoperatively to 112.9+/-11.9 degrees postoperatively (p=0.000). Among patients with bilateral osteoarthritis, the knee function scores were significantly higher in patients who had undergone bilateral versus unilateral TKA (90.0+/-11.5 and 78.8+/-10.8, respectively; p=0.007). None of the patients had patellar tracking abnormality intraoperatively; thus, there was no need for lateral retinacular release. Postoperative clinical and radiographic assessments showed no signs of instability or loosing. Clinical and radiographic loosening of the patella and osteolysis were not observed in patients who had undergone patellar replacement. No changes were observed in the tracking and position of the protheses. Neurovascular injury did not occur. One patient who developed early infection of the knee that required a two-stage revision was assessed as failure. CONCLUSION: In our study, lateral retinacular release was not needed due to achievement of proper patellar tracking in TKA operations with the midvastus approach, and satisfactory clinical and radiographic results were obtained.
20231422 Complement receptor 2/CD21- human naive B cells contain mostly autoreactive unresponsive c 2010 Jun 17 Complement receptor 2-negative (CR2/CD21(-)) B cells have been found enriched in patients with autoimmune diseases and in common variable immunodeficiency (CVID) patients who are prone to autoimmunity. However, the physiology of CD21(-/lo) B cells remains poorly characterized. We found that some rheumatoid arthritis (RA) patients also display an increased frequency of CD21(-/lo) B cells in their blood. A majority of CD21(-/lo) B cells from RA and CVID patients expressed germline autoreactive antibodies, which recognized nuclear and cytoplasmic structures. In addition, these B cells were unable to induce calcium flux, become activated, or proliferate in response to B-cell receptor and/or CD40 triggering, suggesting that these autoreactive B cells may be anergic. Moreover, gene array analyses of CD21(-/lo) B cells revealed molecules specifically expressed in these B cells and that are likely to induce their unresponsive stage. Thus, CD21(-/lo) B cells contain mostly autoreactive unresponsive clones, which express a specific set of molecules that may represent new biomarkers to identify anergic B cells in humans.
20194724 Triptolide inhibits IL-12/IL-23 expression in APCs via CCAAT/enhancer-binding protein alph 2010 Apr 1 Triptolide is a biologically active component purified from Chinese herbal plant Tripterygium wilfordii Hook F. It is widely used in East Asia for treatment of systemic lupus erythematosus, rheumatoid arthritis, nephritis, Bechect's disease, psoriasis, atopic dermatitis, and asthma. However, its immunological mechanisms are poorly understood. IL-12 and IL-23 are closely related heterodimeric cytokines that share the common subunit p40. They are produced by APCs and are key factors in the generation and effector functions of Th1 and Th17 cells, respectively. They have been strongly implicated in the pathogenesis of several autoimmune disorders. In this study, we investigated the molecular mechanism whereby triptolide inhibits the expression of the p40 gene in APCs. We demonstrate that triptolide does so at the transcriptional level in part through targeting CCAAT/enhancer-binding protein-alpha (C/EBPalpha), which directly interacts with the p40 promoter and inhibits its transcription in inflammatory macrophages. Triptolide can activate the transcription of C/EBPalpha, and phosphorylation of Ser21 and Thr222/226 critical for C/EBPalpha inhibition of p40. Further, activation of C/EBPalpha by triptolide is dependent on upstream kinases ERK1/2 and Akt-GSK3beta. This study provides mechanistic insights into the immunomodulatory capacity of triptolide and has strong implications for its therapeutic applications in autoimmune diseases.
19740314 A proinflammatory cytokine interleukin-32beta promotes the production of an anti-inflammat 2009 Sep A new proinflammatory cytokine interleukin-32 (IL-32) has six isoforms. Although IL-32 can be detected in sera from patients suffering from Crohn's disease and rheumatoid arthritis, it is unclear which isoforms are involved. To this end, we investigated the functions of the most abundant IL-32beta by generating K562-IL-32beta stable cell lines. This report confirms, using IL-32 small interfering RNA, that IL-32beta induces an anti-inflammatory cytokine IL-10 in K562-IL-32beta cells and U937 promonocytic cells, which express endogenous IL-32beta upon phorbol 12-myristate 13-acetate (PMA) treatment, and monocyte-derived dendritic cells (DC) upon lipopolysaccharide (LPS) treatment. Interleukin-32beta was induced in monocyte-derived macrophages by LPS and in monocyte-derived DC by LPS, poly(I:C), or anti-CD40 antibody, but was not induced by PMA. We showed that IL-32beta expression was increased in a time-dependent manner in monocyte-derived DC upon LPS treatment and peaked at 24 hr. Production of IL-10 was exactly coincident with IL-32beta expression, but IL-1beta and tumour necrosis factor-alpha production peaked at 6 hr after LPS treatment, then steeply declined. Interleukin-12 p40 was induced at 9 hr and gradually increased until 48 hr, at which time IL-32beta and IL-10 were no longer increased. Knock-down of IL-32beta by IL-32 small interfering RNA led to the decrease of IL-10, but the increase of IL-12 in monocyte-derived DC, which means that IL-32beta promotes IL-10 production, but limits IL-12 production. We also showed that IL-10 neutralization increases IL-12, IL-1beta and tumour necrosis factor-alpha production, which implies that IL-10 suppresses such proinflammatory cytokines. Taken together, our results suggest that IL-32beta upregulates the production of an anti-inflammatory cytokine IL-10, and then IL-10 suppresses proinflammatory cytokines.
19155511 The adaptor protein CIKS/Act1 is essential for IL-25-mediated allergic airway inflammation 2009 Feb 1 IL-17 is the signature cytokine of recently discovered Th type 17 (Th17) cells, which are prominent in defense against extracellular bacteria and fungi as well as in autoimmune diseases, such as rheumatoid arthritis and experimental autoimmune encephalomyelitis in animal models. IL-25 is a member of the IL-17 family of cytokines, but has been associated with Th2 responses instead and may negatively cross-regulate Th17/IL-17 responses. IL-25 can initiate an allergic asthma-like inflammation in the airways, which includes recruitment of eosinophils, mucus hypersecretion, Th2 cytokine production, and airways hyperreactivity. We demonstrate that these effects of IL-25 are entirely dependent on the adaptor protein CIKS (also known as Act1). Surprisingly, this adaptor is necessary to transmit IL-17 signals as well, despite the very distinct biologic responses that these two cytokines elicit. We identify CD11c(+) macrophage-like lung cells as physiologic relevant targets of IL-25 in vivo.
19116146 sPLA2-IIa is an inflammatory mediator when the ocular surface is compromised. 2009 May sPLA2-IIa is an enzyme at high concentration in tears that has been known as an innate barrier of the ocular surface against microbial infection. sPLA2-IIa and other enzymes in the same protein family are known to hydrolyze fatty acids resulting in the generation of free arachidonic acid (AA) and lysophospholipids, which are the precursors of pro-inflammatory lipid mediators, such as PGE(2). sPLA2-IIa has been shown to be an inflammatory mediator in non-ocular inflammatory diseases such as rheumatoid arthritis (RA). It was also found to be increased in the tears of the patients with dry eye disease, chronic blepharitis and contact lens intolerance. However, the role of sPLA2-IIa in chronic ocular surface inflammation has yet to be determined. In the current study, we examined the potential role of sPLA2-IIa in inflammation of ocular surface diseases. Our results show that the activity of sPLA2-IIa was significantly increased in tears from dry eye disease patients compared with that from normal subjects. Also, sPLA2-IIa stimulated the production of PGE(2) in ocular surface epithelial cell cultures. The stimulating effect was markedly enhanced when the cells or tissues were pre-compromised with TNF-alpha, IL-1beta or desiccation. Furthermore, sPLA2-IIa stimulated inflammatory cytokine production in the ocular surface epithelial cell cultures in vitro. To our knowledge, this is the first report regarding the role of sPLA2-IIa as an inflammatory mediator in ocular surface inflammation. These findings indicate that sPLA2-IIa may play an important role in chronic ocular surface inflammation, especially when the ocular surface is compromised.
19110536 Analysis of 17 autoimmune disease-associated variants in type 1 diabetes identifies 6q23/T 2009 Mar As a result of genome-wide association studies in larger sample sets, there has been an increase in identifying genes that influence susceptibility to individual immune-mediated diseases, as well as evidence that some genes are associated with more than one disease. In this study, we tested 17 single nucleotide polymorphisms (SNP) from 16 gene regions that have been reported in several autoimmune diseases including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), ankylosing spondylitis (AS) and Crohn's disease (CD) to determine whether the variants are also associated with type 1 diabetes (T1D). In up to 8010 cases and 9733 controls we found some evidence for an association with T1D in the regions containing genes: 2q32/STAT4, 17q21/STAT3, 5p15/ERAP1 (ARTS1), 6q23/TNFAIP3 and 12q13/KIF5A/PIP4K2C with allelic P-values ranging from 3.70 x 10(-3) to 3.20 x 10(-5). These findings extend our knowledge of susceptibility locus sharing across different autoimmune diseases, and provide convincing evidence that the RA/SLE locus 6q23/TNFAIP3 is a newly identified T1D locus.
19731364 A bone-protective role for IL-17 receptor signaling in ovariectomy-induced bone loss. 2009 Oct Post-menopausal osteoporosis is considered to be an inflammatory process, in which numerous pro-inflammatory and T-cell-derived cytokines play a bone-destructive role. IL-17A is the signature cytokine of the pro-inflammatory Th17 population and plays dichotomous roles in diseases that affect bone turnover. Although IL-17A promotes bone loss in rheumatoid arthritis, it is protective against pathogen-induced bone destruction in a periodontal disease model. We used a model of ovariectomy-induced osteoporosis (OVX) in IL-17 receptor (IL-17RA)(-/-) mice to evaluate the role of the IL-17A in bone loss caused by estrogen deficiency. Unexpectedly, IL-17RA(-/-) mice were consistently and markedly more susceptible to OVX-induced bone loss than controls. There were no changes in prototypical Th1, Th2 or Th17 cytokines in serum that could account for increased bone loss. However, IL-17RA(-/-) mice exhibited constitutively elevated leptin, which further increased following OVX. Consistently, IL-17A and IL-17F treatment of 3T3-L1 pre-adipocytes inhibited adipogenesis, leading to reduced production of leptin. In addition to its role in regulating metabolism and satiety, leptin can regulate bone turnover. Accordingly, these data show that IL-17A negatively regulates adipogenesis and subsequent leptin expression, which correlates with increased bone destruction during OVX.
19380800 Impaired CD4 and CD8 effector function and decreased memory T cell populations in ICOS-def 2009 May 1 Interaction of ICOS with its ligand is essential for germinal center formation, T cell immune responses, and development of autoimmune diseases. Human ICOS deficiency has been identified worldwide in nine patients with identical ICOS mutations. In vitro studies of the patients to date have shown only mild T cell defect. In this study, we report an in-depth analysis of T cell function in two siblings with novel ICOS deficiency. The brother displayed mild skin infections and impaired Ig class switching, whereas the sister had more severe symptoms, including immunodeficiency, rheumatoid arthritis, inflammatory bowel disease, interstitial pneumonitis, and psoriasis. Despite normal CD3/CD28-induced proliferation and IL-2 production in vitro, peripheral blood T cells in both patients showed a decreased percentage of CD4 central and effector memory T cells and impaired production of Th1, Th2, and Th17 cytokines upon CD3/CD28 costimulation or PMA/ionophore stimulation. The defective polarization into effector cells was associated with impaired induction of T-bet, GATA3, MAF, and retinoic acid-related orphan nuclear hormone receptor (RORC). Reduced CTLA-4(+)CD45RO(+)FoxP3(+) regulatory T cells and diminished induction of inhibitory cell surface molecules, including CTLA-4, were also observed in the patients. T cell defect was not restricted to CD4 T cells because reduced memory T cells and impaired IFN-gamma production were also noted in CD8 T cells. Further analysis of the patients demonstrated increased induction of receptor activator of NF-kappaB ligand (RANKL), lack of IFN-gamma response, and loss of Itch expression upon activation in the female patient, who had autoimmunity. Our study suggests that extensive T cell dysfunction, decreased memory T cell compartment, and imbalance between effector and regulatory cells in ICOS-deficient patients may underlie their immunodeficiency and/or autoimmunity.
19200602 Mutual activation of CD4+ T cells and monocytes mediated by NKG2D-MIC interaction requires 2009 Apr The activating receptor NKG2D is mainly expressed by human CD8(+) T cells and NK cells but normally absent on CD4(+) T cells. However, a subset of autoreactive NKG2D(+)CD4(+) T cells has been found to exist in some autoimmune disease such as rheumatoid arthritis (RA) and to participate in the imbalance of immune response and inflammation. Up to date this observation has been extended to some autoimmune diseases such as RA and Crohn's disease and the mechanism underlying the presence of this type of NKG2D(+)CD4(+) T cells has not been delineated yet. In this study, we found that a substantial proportion of CD4(+) T cells expressed NKG2D in the PBMC of SLE patients. We also found that monocytes in SLE aberrantly expressed the NKG2D ligand of MHC class I chain-related (MIC) molecules and membrane-bound IL-15 (mIL-15) at the cell surface. When cultured with the sera from SLE patients, the monocytes from healthy volunteers could be induced to express MIC and mIL-15. However, this induced expression of MIC and mIL-15 could be blocked with anti-IFN-gamma receptor (anti-IFN-gammaR) antibody. We further demonstrated that NKG2D could be induced on normal CD4(+) T cells either cocultured with monocytes from patients with SLE, or monocytes from healthy volunteers but pretreated with IFN-gamma. Moreover, Th1 cytokines were found to be produced by NKG2D(+)CD4(+) T cells in the coculture system. By transwell assay, we found that both NKG2D expression and Th1 cytokines production depended on the cell-cell contact. These results indicate that the elevated sera IFN-gamma may be responsible for MIC and mIL-15 induction on monocytes in SLE; mIL-15 on monocytes contribute to NKG2D receptor induction on a subset of CD4(+) T cells. Moreover, CD14(+) monocytes promote NKG2D(+)CD4(+) T cells activation through the NKG2D-MIC engagement in the pathogenesis of SLE.
19194982 Bayesian intervals for linkage locations. 2009 Nov Intermediate fine mapping has received considerable attention recently, with the goal of providing statistically precise and valid chromosomal regions for fine mapping following initial identification of broad regions that are linked to a disease. The following classes of methods have been proposed and compared in the literature: (1) LOD-support intervals, (2) generalized estimating equations, (3) bootstrap, and (4) confidence set inference framework. These methods provide confidence intervals either with coverage levels deviating from the nominal confidence levels or that are not fully efficient. Here, we propose a novel Bayesian method for constructing such intervals using affected sibling pair data. The susceptibility gene location is treated as a parameter in this method, with a uniform prior. A Metropolis-Hastings algorithm is implemented to sample from the posterior distribution and highest posterior density intervals of the disease gene locations are constructed. Correct coverage levels are maintained by our method. Both simulation studies and an application to a rheumatoid arthritis dataset demonstrate the improved efficiency of the Bayesian intervals compared with existing methods.
20824169 Cheminformatics-based drug design approach for identification of inhibitors targeting the 2010 Aug 31 BACKGROUND: MMP-13, a zinc dependent protease which catalyses the cleavage of type II collagen, is expressed in osteoarthritis (OA) and rheumatoid arthritis (RA) patients, but not in normal adult tissues. Therefore, the protease has been intensively studied as a target for the inhibition of progression of OA and RA. Recent reports suggest that selective inhibition of MMP-13 may be achieved by targeting the hemopexin (Hpx) domain of the protease, which is critical for substrate specificity. In this study, we applied a cheminformatics-based drug design approach for the identification and characterization of inhibitors targeting the amino acid residues characteristic to Hpx domain of MMP-13; these inhibitors may potentially be employed in the treatment of OA and RA. METHODOLOGY/PRINCIPAL FINDINGS: Sequence-based mutual information analysis revealed five characteristic (completely conserved and unique), putative functional residues of the Hpx domain of MMP-13 (these residues hereafter are referred to as HCR-13(pf)). Binding of a ligand to as many of the HCR-13(pf) is postulated to result in an increased selective inhibition of the Hpx domain of MMP-13. Through the in silico structure-based high-throughput virtual screening (HTVS) method of Glide, against a large public library of 16908 molecules from Maybridge, PubChem and Binding, we identified 25 ligands that interact with at least one of the HCR-13(pf). Assessment of cross-reactivity of the 25 ligands with MMP-1 and MMP-8, members of the collagenase family as MMP-13, returned seven lead molecules that did not bind to any one of the putative functional residues of Hpx domain of MMP-1 and any of the catalytic active site residues of MMP-1 and -8, suggesting that the ligands are not likely to interact with the functional or catalytic residues of other MMPs. Further, in silico analysis of physicochemical and pharmacokinetic parameters based on Lipinski's rule of five and ADMET (absorption, distribution, metabolism, excretion and toxicity) respectively, suggested potential utility of the compounds as drug leads. CONCLUSIONS/SIGNIFICANCE: We have identified seven distinct drug-like molecules binding to the HCR-13(pf) of MMP-13 with no observable cross-reactivity to MMP-1 and MMP-8. These molecules are potential selective inhibitors of MMP-13 that can be experimentally validated and their backbone structural scaffold could serve as building blocks in designing drug-like molecules for OA, RA and other inflammatory disorders. The systematic cheminformatics-based drug design approach applied herein can be used for rational search of other public/commercial combinatorial libraries for more potent molecules, capable of selectively inhibiting the collagenolytic activity of MMP-13.