173 research outputs found

    Mechanisms of tissue injury in lupus nephritis

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    Systemic lupus erythematosus is a prototypic autoimmune disease characterized by autoantibody production and immune complex formation/deposition in target organs such as the kidney. Resultant local inflammation then leads to organ damage. Nephritis, a major cause of morbidity and mortality in patients with lupus, occurs in approximately 50% of lupus patients. In the present review, we provide an overview of the current research and knowledge concerning mechanisms of renal injury in both lupus-prone mouse models and human lupus patients

    Bone Marrow Transplantation Reproduces the Tristetraprolin-Deficiency Syndrome in Recombination Activating Gene-2 (-/-) Mice: Evidence That Monocyte/Macrophage Progenitors May Be Responsible for TNFα Overproduction

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    Tristetraprolin-deficient [TTP (-/-)] mice exhibit a complex syndrome of myeloid hyperplasia, cachexia, dermatitis, autoimmunity, and erosive arthritis. Virtually the entire syndrome can be prevented by the repeated injection of anti-TNFα antibodies (Taylor, G.A., E. Carballo, D.M. Lee, W.S. Lai, M.J. Thompson, D.D. Patel, D.I. Schenkman, G.S. Gilkeson, H.E. Broxmeyer, B.F. Haynes, and P.J. Blackshear. 1996. Immunity. 4:445–454). In the present study, we transplanted bone marrow from TTP (-/-) and (+/+) mice into recombination activating gene-2 (-/-) mice. After a lag period of several months, marrow transplantation from the (-/-) but not the (+/+) mice resulted in the full syndrome associated with TTP deficiency, suggesting that hematopoietic progenitors are responsible for the development of the syndrome. Western blot analysis of supernatants from cultured TTP-deficient macrophages derived from the peritoneal cavity or bone marrow of adult TTP (-/-) mice, or from fetal liver, demonstrated an increased accumulation of TNFα after stimulation with LPS compared to control cells, and also increased accumulation of TNFα mRNA. This difference was not observed with cultured fibroblasts or T and B lymphocytes. These data suggest that macrophages are among the cells responsible for the effective excess of TNFα that leads to the pathology reported in TTP (-/-) animals, and that macrophage progenitors may be involved in the transplantability of this syndrome

    The Impact of Vitamin D on Dendritic Cell Function in Patients with Systemic Lupus Erythematosus

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    Excessive activity of dendritic cells (DCs) is postulated as a central disease mechanism in Systemic Lupus Erythematosus (SLE). Vitamin D is known to reduce responsiveness of healthy donor DCs to the stimulatory effects of Type I IFN. As vitamin D deficiency is reportedly common in SLE, we hypothesized that vitamin D might play a regulatory role in the IFNalpha amplification loop in SLE. Our goals were to investigate the relationship between vitamin D levels and disease activity in SLE patients and to investigate the effects of vitamin D on DC activation and expression of IFNalpha-regulated genes in vitro.In this study, 25-OH vitamin D (25-D) levels were measured in 198 consecutively recruited SLE patients. Respectively, 29.3% and 11.8% of African American and Hispanic SLE patient had 25-D levels <10 ng/ml. The degree of vitamin D deficiency correlated inversely with disease activity; R = -.234, p = .002. In 19 SLE patients stratified by 25-D levels, there were no differences between circulating DC number and phenotype. Monocyte-derived DCs (MDDCs) of SLE patients were normally responsive to the regulatory effects of vitamin D in vitro as evidenced by decreased activation in response to LPS stimulation in the presence of 1,25-D. Additionally, vitamin D conditioning reduced expression of IFNalpha-regulated genes by healthy donor and SLE MDDCs in response to factors in activating SLE plasma.We report on severe 25-D deficiency in a substantial percentage of SLE patients tested and demonstrate an inverse correlation with disease activity. Our results suggest that vitamin D supplementation will contribute to restoring immune homeostasis in SLE patients through its inhibitory effects on DC maturation and activation. We are encouraged to support the importance of adequate vitamin D supplementation and the need for a clinical trial to assess whether vitamin D supplementation affects IFNalpha activity in vivo and, most importantly, improves clinical outcome

    A motivação e a cooperação desportiva no atletismo

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    A educação física para as crianças e jovens, consiste num período crítico do percurso educacional, dado que pode promover o seu futuro envolvimento desportivo e decisões acerca da sua participação em actividades físicas futuras. Deste modo, o estudo de modelos ou a identificação de determinantes psicológicas, assume-se como uma necessidade para o desenvolvimento de intervenções adequadas para o aumento dos níveis de actividade física. A orientação motivacional e o sentido de cooperação, são factores de primordial importância na coordenação e no sucesso de diversas actividades humanas, e de impacto bem visível no âmbito do desporto. Assim, o presente trabalho destina-se à verificação das possibilidades de correlação entre orientação motivacional e sentido de cooperação em participantes de uma mesma modalidade desportiva, neste caso o atletismo, para o que se utilizou o “Task and Ego Orientation in Sport Questionnaire” (TEOSQ), na versão portuguesa desenvolvido por Duda e colaboradores (1989, 1992, citado por Cruz, 1996), de Fonseca e Brito, (2006) e o Cuestionario de Cooperación Deportiva (CCD), igualmente na versão portuguesa, de Almeida, Garcia-Mas, Lameiras, Olmedílla, Ortega, Martins, (2006). A amostra foi constituída por 52 atletas, onde 51,9% dos sujeitos são do sexo masculino e 48,1% são do sexo feminino, de diversas especialidades.ABSTRACT: Physical education for children and young people is a critical period of the educational process, as this selling may promote individual`s futures involvement in physical activity and sports, and may influence young persons decisions about future sport and activity participation. Therefore, the study of models and identification of psychology variables, underscores the need of developing interventions to increase physical activity. The motivational orientation and the direction of cooperation are factors of primordial importance in the coordination and the success of diverse activities human beings, and well visible impact in the scope of the sport. Thus, the present work destines it verification of the possibilities of correlation between the motivational orientation an direction of cooperation in participants of one same porting modality, in this in case that the track and field so that it was used “Task and Ego Orientation in Sport Questionnaire” (TEOSQ), in the Portuguese version developed by Duda and Collaborators (1989, 1992, cited for Cruz, 1996), and the Cuestionario de Cooperación Deportiva (CCD),equally in the Portuguese version of Almeida, Garcia-Mas, Lameiras, Olmedílla, Ortega, Martins, (2006). A sample of 52 athletes, of diverse modalities

    Clinical and Serologic Manifestations of Autoimmune Disease in MRL-lpr/lpr Mice Lacking Nitric Oxide Synthase Type 2

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    Nitric oxide (NO) is an important mediator of the inflammatory response. MRL–lpr/lpr mice overexpress inducible nitric oxide synthase (NOS2) and overproduce NO in parallel with the development of an autoimmune syndrome with a variety of inflammatory manifestations. In previous studies, we showed that inhibiting NO production with the nonselective nitric oxide synthase (NOS) inhibitor NG-monomethyl–arginine reduced glomerulonephritis, arthritis, and vasculitis in MRL–lpr/lpr mice. To define further the role of NO and NOS2 in disease in MRL–lpr/lpr mice, mice with targeted disruption of NOS2 were produced by homologous recombination and bred to MRL–lpr/lpr mice to the N4 generation. MRL–lpr/lpr littermates homozygous for disrupted NOS2 (−/−), heterozygous for disrupted NOS2 (+/−), or wildtype (+/+) were derived for this study. Measures of NO production were markedly decreased in the MRL-lpr/lpr (−/−) mice compared with MRL-lpr/lpr (+/+) mice, with intermediate production by the MRL-lpr/lpr (+/−) mice. There was no detectable NOS2 protein by immunoblot analysis of the spleen, liver, kidney, and peritoneal macrophages of the (−/−) animals, whereas that of (+/+) was high and (+/−) intermediate. The (−/−) mice developed glomerular and synovial pathology similar to that of the (+/−) and (+/+) mice. However, (−/−) mice and (+/−) mice had significantly less vasculitis of medium-sized renal vessels than (+/+) mice. IgG rheumatoid factor levels were significantly lower in the (−/−) mice as compared with (+/+) mice, but levels of anti-DNA antibodies were comparable in all groups. Our findings show that NO derived from NOS2 has a variable impact on disease manifestations in MRL-lpr/lpr mice, suggesting heterogeneity in disease mechanisms

    Genetic associations of leptin-related polymorphisms with systemic lupus erythematosus

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    Leptin is abnormally elevated in the plasma of patients with systemic lupus erythematosus (SLE), where it is thought to promote and/or sustain pro-inflammatory responses. Whether this association could reflect an increased genetic susceptibility to develop SLE is not known, and studies of genetic associations with leptin-related polymorphisms in SLE patients have been so far inconclusive. Here we genotyped DNA samples from 15,706 SLE patients and healthy matched controls from four different ancestral groups, to correlate polymorphisms of genes of the leptin pathway to risk for SLE. It was found that although several SNPs showed weak associations, those associations did not remain significant after correction for multiple testing. These data do not support associations between defined leptin-related polymorphisms and increased susceptibility to develop SLE. © 2015 Elsevier Inc

    The Role of Genetic Variation Near Interferon-Kappa in Systemic Lupus Erythematosus

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    Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by increased type I interferons (IFNs) and multiorgan inflammation frequently targeting the skin. IFN-kappa is a type I IFN expressed in skin. A pooled genome-wide scan implicated the IFNK locus in SLE susceptibility. We studied IFNK single nucleotide polymorphisms (SNPs) in 3982 SLE cases and 4275 controls, composed of European (EA), African-American (AA), and Asian ancestry. rs12553951C was associated with SLE in EA males (odds ratio = 1.93, P = 2.5 × 10−4), but not females. Suggestive associations with skin phenotypes in EA and AA females were found, and these were also sex-specific. IFNK SNPs were associated with increased serum type I IFN in EA and AA SLE patients. Our data suggest a sex-dependent association between IFNK SNPs and SLE and skin phenotypes. The serum IFN association suggests that IFNK variants could influence type I IFN producing plasmacytoid dendritic cells in affected skin
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