RESUMO
We have previously identified Cia10 as an arthritis severity and articular damage quantitative trait locus. In this study, we used Illumina RatRef-12 microarrays to analyze the expression of 21,922 genes in synovial tissues from arthritis-susceptible DA and arthritis-protected DA.ACI(Cia10) congenics with pristane-induced arthritis. 310 genes had significantly different expression. The genes upregulated in DA, and reciprocally downregulated in DA.ACI(Cia10) included IL-11, Ccl12 and Cxcl10, as well as genes implicated in Th17 responses such as IL-17A, IL-6, Ccr6, Cxcr3 and Stat4. Suppressors of immune responses Tgfb and Vdr, and inhibitors of oxidative stress were upregulated in congenics. There was an over-representation of genes implicated in cancer and cancer-related phenotypes such as tumor growth and invasion among the differentially expressed genes. Cancer-favoring genes like Ctsd, Ikbke, and Kras were expressed in increased levels in DA, whereas inhibitors of cancer phenotypes such as Timp2, Reck and Tgfbr3 were increased in DA.ACI(Cia10). These results suggest that Cia10 may control arthritis severity, synovial hyperplasia and joint damage via the regulation of the expression of cancer-related genes, inflammatory mediators and Th17-related markers. These new findings have the potential to generate new targets for therapies aimed at reducing arthritis severity and joint damage in rheumatoid arthritis.
Assuntos
Artrite Experimental/genética , Artrite Reumatoide/genética , Regulação da Expressão Gênica , Genes Neoplásicos , Locos de Características Quantitativas , Membrana Sinovial/metabolismo , Células Th17/metabolismo , Animais , Apoptose/genética , Artrite Experimental/metabolismo , Artrite Reumatoide/metabolismo , Sobrevivência Celular/genética , Quimiocinas/genética , Cromossomos de Mamíferos , Citocinas/genética , Redes Reguladoras de Genes , Mediadores da Inflamação/metabolismo , Masculino , MicroRNAs/genética , NF-kappa B/genética , Estresse Oxidativo/genética , Fenótipo , Polimorfismo Genético , Ratos , Índice de Gravidade de Doença , Transdução de SinaisRESUMO
Neutrophils are required for the development of arthritis in rodents, and are the predominant cell in the synovial fluid of active rheumatoid arthritis. We hypothesized that neutrophil migration into the inflammed joint is genetically regulated. In addition, this genetic regulation would be accounted for by one of the arthritis loci that we have previously identified in an intercross between arthritis-susceptible DA and arthritis-resistant ACI rats studied for collagen-induced arthritis. We used the synovial-like air pouch model injected with carrageenan, and tested DA, ACI, and four congenic strains. ACI exudates had a significantly lower number of neutrophils compared with DA. Transfer of DA alleles at Cia7 into the ACI background, as in ACI.DA(Cia7) congenics, was enough to increase exudate neutrophil numbers to levels identical to DA, and this locus accounted for the difference between parental strains. None of the other congenic intervals explained the differences in exudate neutrophil counts. In conclusion, we have identified a novel function for Cia7, and determined that it regulates neutrophil migration into a synovial-like inflammatory site. Our data revealed no intrinsic defect in neutrophil responses to chemotactic agents, and suggest that Cia7 regulates an as yet unidentified factor central to neutrophil recruitment into inflammed tissues.
Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Movimento Celular/fisiologia , Neutrófilos/fisiologia , Locos de Características Quantitativas/genética , Líquido Sinovial/metabolismo , Animais , Carragenina , Quimiocinas/genética , Quimiotaxia/imunologia , Ensaio de Imunoadsorção Enzimática , Ratos , Ratos Endogâmicos ACI , Análise de Sequência de DNA , Especificidade da Espécie , Líquido Sinovial/imunologiaRESUMO
Cia27 on rat chromosome 10 is a collagen-induced arthritis (CIA) severity quantitative trait locus originally identified in a study of (DA x ACI) F2. As an initial step towards the positional cloning of the Cia27 gene, a 17 cM (21 Mb) interval from the DA strain (arthritis-susceptible) containing the two-logarithm of odds support interval comprising Cia27 was introgressed into the ACI (arthritis-resistant) background through genotype-guided congenic breeding. ACI.DA(Cia27) congenics developed a significantly more severe form of arthritis (CIA), with a 5.9-fold increase in median arthritis severity index, a parameter known to correlate with synovial inflammation, and cartilage and bone erosions, compared with ACI (P< or =0.001). The arthritis severity enhancing effect could be detected from day 21 onwards. Rats heterozygous at the congenic interval developed a disease similar to ACI rats, suggesting that DA alleles operate in a recessive manner. Levels of autoantibodies anti-rat type II collagen did not correlate with arthritis severity. Synovial tissue mRNA levels of interleukin-1beta (IL-1beta) were significantly increased in ACI.DA(Cia27) congenics compared with ACI. These results demonstrate that Cia27 harbors a novel arthritis severity regulatory gene. The identification of this gene should facilitate the identification of the rheumatoid arthritis gene mapped to the human syntenic region on chromosome 17q22-q25.
Assuntos
Artrite Experimental/genética , Artrite Experimental/patologia , Artrite Reumatoide/genética , Cromossomos Humanos Par 17 , Cromossomos de Mamíferos , Sintenia , Alelos , Animais , Animais Congênicos , Autoanticorpos/sangue , Autoanticorpos/metabolismo , Modelos Animais de Doenças , Marcadores Genéticos , Humanos , Articulações/patologia , Característica Quantitativa Herdável , Ratos , Ratos Endogâmicos ACI , Ratos Endogâmicos Dahl , Índice de Gravidade de Doença , Organismos Livres de Patógenos EspecíficosRESUMO
New fluorescent ligands for adenosine receptors (ARs), obtained by the insertion, in the N(6) position of NECA, of NBD-moieties with linear alkyl spacers of increasing length, proved to possess a high affinity and selectivity for the A(3) subtype expressed in CHO cells. In fluorescence microscopy assays, compound 2d, the most active and selective for human A(3)-AR, permitted visualization and localization of this human receptor subtype, showing its potential suitability for internalization and trafficking studies in living cells.