Objective To estimate the prevalence of spondyloarthritis (SpA) in reference to HLA-B27 in the French population. Methods In 1989, 20 625 employees of the French national gas and electricity company ...aged 35–50 years were enrolled in the GAZEL cohort. In 2010, 18 757 still active participants were screened by a questionnaire validated for the detection of SpA. Responders with available DNA were retained for further studies. Pelvic radiograph and HLA-B27 typing were performed in all the self-reported cases of SpA or psoriatic arthritis. Self-reported diagnosis was verified by a qualified rheumatologist. HLA-B27 determination was also performed in subjects without any SpA feature. Results The target population consisted of 6556 responders with available DNA. Their male:female ratio was 3.6 and their mean age was 65.5±3.3 years. A diagnosis of SpA was confirmed in 32 of the 72 self-reported cases, 75% of them being HLA-B27 positive. Estimated SpA prevalence adjusted for sex was 0.43% (95% CI 0.26% to 0.70%). HLA-B27 positivity rate in 2466 healthy controls was 6.9% (95% CI 5.9% to 7.9%). The relative risk of SpA in HLA-B27 positive individuals was 39 (95% CI 17 to 86). Conclusions We estimated the prevalence of SpA in the French population in 2010 to 0.43%. With an estimated prevalence of 75.0% in SpA and 6.9% in healthy controls, HLA-B27 increased the disease risk 39-fold, as compared with HLA-B27 negative subjects.
Gene expression analysis of target organs might help provide new insights into the pathogenesis of autoimmune diseases. We used global gene expression profiling of minor salivary glands to identify ...patterns of gene expression in patients with primary Sjögren's syndrome (pSS), a common and prototypic systemic autoimmune disease. Gene expression analysis allowed for differentiating most patients with pSS from controls. The expression of 23 genes in the IFN pathways, including two Toll-like receptors (TLR8 and TLR9), was significantly different between patients and controls. Furthermore, the increased expression of IFN-inducible genes, BAFF and IFN-induced transmembrane protein 1, was also demonstrated in ocular epithelial cells by quantitative RT-PCR. In vitro activation showed that these genes were effectively modulated by IFNs in salivary gland epithelial cells, the target cells of autoimmunity in pSS. The activation of IFN pathways led us to investigate whether plasmacytoid dendritic cells were recruited in salivary glands. These IFN-producing cells were detected by immunohistochemistry in all patients with pSS, whereas none was observed in controls. In conclusion, our results support the pathogenic interaction between the innate and adaptive immune system in pSS. The persistence of the IFN signature might be related to a vicious circle, in which the environment interacts with genetic factors to drive the stimulation of salivary TLRs.
Fas-associated death domain (FADD) is a key adaptor molecule involved in numerous physiological processes including cell death, proliferation, innate immunity and inflammation. Therefore, changes in ...FADD expression have dramatic cellular consequences. In mice and humans, FADD regulation can occur through protein secretion. However, the molecular mechanisms accounting for human FADD secretion were still unknown. Here we report that canonical, non-canonical, but not alternative, NLRP3 inflammasome activation in human monocytes/macrophages induced FADD secretion. NLRP3 inflammasome activation by the bacterial toxin nigericin led to the proinflammatory interleukin-1β (IL-1β) release and to the induction of cell death by pyroptosis. However, we showed that FADD secretion could occur in absence of increased IL-1β release and pyroptosis and, reciprocally, that IL-1β release and pyroptosis could occur in absence of FADD secretion. Especially, FADD, but not IL-1β, secretion following NLRP3 inflammasome activation required extracellular glucose. Thus, FADD secretion was an active process distinct from unspecific release of proteins during pyroptosis. This FADD secretion process required K
efflux, NLRP3 sensor, ASC adaptor and CASPASE-1 molecule. Moreover, we identified FADD as a leaderless protein unconventionally secreted through microvesicle shedding, but not exosome release. Finally, we established human soluble FADD as a new marker of joint inflammation in gout and rheumatoid arthritis, two rheumatic diseases involving the NLRP3 inflammasome. Whether soluble FADD could be an actor in these diseases remains to be determined. Nevertheless, our results advance our understanding of the mechanisms contributing to the regulation of the FADD protein expression in human cells.
Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic ...process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40–OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease,we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation.
We sought to assess whether nailfold videocapillaroscopy (NVC) patterns are associated with levels of angiogenic factors in systemic sclerosis (SSc).
Circulating endothelial progenitor cells (EPCs) ...and circulating endothelial cells (CECs) were measured in the peripheral blood of 60 consecutive SSc patients. Serum levels of eight endothelial markers were measured first in these 60 patients, and then in an independent replication cohort of 43 SSc patients in case of association with NVC patterns. NVC patterns were determined by four independent investigators blinded to vascular markers.
Patients with the late-NVC pattern exhibited lower EPC levels (P < 0.0001) and higher VEGF levels (P = 0.03). Higher VEGF levels were confirmed to be associated with the late-NVC pattern in the replication cohort (P = 0.01). By multivariate analysis focused on biomarkers, lower EPC (P = 0.03) and higher VEGF levels (P = 0.001) were independently associated with the late-NVC pattern. In an alternate multivariate model including these two factors and SSc-related disease characteristics, lower EPC counts (P = 0.005), higher VEGF levels (P = 0.01), a history of digital ulcers (P = 0.04), and a modified Rodnan skin score > 14 (P < 0.0001) were independently associated with the late-NVC pattern.
Our data revealed decreased EPC counts and increased VEGF levels in patients with the late-NVC pattern. Further studies are now needed to determine the role of VEGF and EPCs in endothelial injury and repair in SSc.
Spondyloarthritis (SpA) is a chronic inflammatory disease affecting primarily axial and peripheral joints and sometimes also extra-articular organs, such as the gut. Rats transgenic for HLA-B27 and ...human β2-microglobulin (B27-Tg rat) develop clinical manifestations resembling human disease. In this model, it has been shown that CD103
conventional dendritic cells (cDCs) exhibited altered functions, likely promoting SpA development. CD4
cDC subpopulation expressing XCR1, a chemokine receptor involved in their migration, have been described to be tolerogenic in steady state. Thus, in this study, we wished to examine the fate of XCR1
cDCs in this animal model of SpA.
cDC populations were isolated from the spleen, mesenteric lymph nodes (MLN), and colonic lamina propria from B27-TG and control nontransgenic (NTG) and/or HLA-B7 transgenic rats after collagenase digestion and density gradient and characterized with flow cytometry or real-time PCR. Migration of cDCs from intestinal mucosa to MLN was assessed, using TLR-7 stimulation with Resiquimod.
We observed a reduced frequency of cCD4
DCs in B27-Tg rats, as compared to control rats. Furthermore, such decrease was not due to excessive death of CD4
cDCs in B27-Tg rats. Interestingly, we observed a decrease frequency of the XCR1
subpopulation among CD4
cDCs in the spleen, MLN, and lamina propria from B27-Tg rats. Finally, after TLR-7 stimulation, the migration of XCR1
cDCs to MLN was proportionally reduced in B27-Tg rats.
Our results demonstrate for the first time a decreased proportion of the tolerogenic XCR1
cDC subpopulation in SpA target organs in B27-Tg rat, which may affect the maintenance of self-tolerance and control of inflammation.
Spondylarthritis (SpA) development in HLA-B27/human β2-microglobulin transgenic rat (B27-rat) is correlated with altered conventional dendritic cell (cDC) function that promotes an inflammatory ...pattern of CD4+T cells, including a biased expansion of pro-inflammatory Th
population and imbalance of regulatory T cells cytokine profile. Transcriptomic analysis revealed that cDCs from B27-rats under express IL-27, an anti-inflammatory cytokine which induces the differentiation of IL-10
regulatory T cells and inhibits Th
cells.
Here, we first investigated whether
addition of exogenous IL-27 could reverse the inflammatory pattern observed in CD4
T cells. Next, we performed preclinical assay using IL-27 to investigate whether
treatment could prevent SpA development in B27-rats.
addition of IL-27 to cocultures of cDCs and CD4
T cell subsets from B27-rats reduced IL-17 and enhanced IL-10 production by T cells. Likewise, IL-27 inhibited the production of IL-17 by CD4
T cells from SpA patients. Interestingly,
treatment with recombinant IL-27 starting before SpA onset, inhibited SpA development in B27-rats through the suppression of IL-17/TNF producing CD4
T cells.
Overall, our results reveal a potent inhibitory effect of IL-27 and highlight this cytokine as a promising new therapeutic target in SpA, especially for SpA patients non responders to currently approved biotherapies.
Objective To evaluate the possible merit of endothelial markers for the prediction of ischaemic digital ulcers in patients with systemic sclerosis (SSc). Methods Circulating endothelial progenitor ...cells (EPC), circulating endothelial cells and serum levels of placental growth factor (PlGF), soluble vascular adhesion molecule and vascular endothelial growth factor were measured in a prospective cohort of 100 SSc patients. The primary outcome was the occurrence of one or more new ischaemic digital ulcers during a planned 3-year follow-up. Results After the follow-up period, 17 patients developed new digital ulcers. By multivariate analysis focused on biomarkers, high PlGF serum levels and low EPC counts were identified as predictors of the occurrence of at least one new digital ulcer. In a secondary model including biomarkers together with clinical SSc characteristics all predictors of digital ulcers defined by p≤0.1 in univariate analysis, high PlGF serum levels (HR 7.26, 95% CI 1.92 to 27.41) and a history of digital ulcers (HR 9.32, 95% CI 1.51 to 59.83) were identified as independent predictors of a new digital ulcer. In an alternative model excluding patients with a history of digital ulcers at baseline, high PlGF serum levels (HR 13.46, 95% CI 1.58 to 114.73) and low EPC counts (HR 7.95, 95% CI 2.09 to 30.09) remained predictive of new digital ulcer occurrence during follow-up. Conclusion This study identified high PlGF serum levels and low circulating EPC counts as predictors of new digital ulcers in SSc. It highlights the critical role of angiogenesis in this vascular outcome. These markers may improve digital ulcer risk stratification and therefore allow earlier therapeutic intervention.
Objective To investigate the contribution of the adhesion receptor DNAX accessory molecule-1 (DNAM-1) in the development of dermal fibrosis on gene inactivation and targeted molecular strategies. ...Methods Human skin expression of DNAM-1 was determined by immunohistochemistry. Mice deficient for DNAM-1 (dnam1−/−) and wild-type controls (dnam1+/+) were injected with bleomycin or NaCl. Infiltrating leucocytes, T cells, B cells and monocytes were quantified and inflammatory cytokines were measured in lesional skin of dnam1−/− and dnam1+/+ mice. The anti-fibrotic potential of a DNAM-1 neutralising monoclonal antibody (mAb) was evaluated in the mouse model of bleomycin-induced dermal fibrosis. Results Overexpression of DNAM-1 was detected in the skin of patients with SSc (systemic sclerosis). Dnam1−/− mice were protected from bleomycin-induced dermal fibrosis with reduction of dermal thickening (75±5%, p=0.03), hydroxyproline content (46±8%, p=0.04) and myofibroblast counts (39±5%, p=0.01). Moreover, the number of T cells was significantly decreased in lesional skin of dnam1−/− mice (69±15%, p=0.0007). Dnam1−/− mice also displayed decreased levels of TNF-α and IL-6 in lesional skin. Consistent with the gene inactivation strategy, treatment of mice with DNAM-1 neutralising mAb prevented dermal fibrosis induced by bleomycin with reduction of dermal thickness (64±6%, p=0.002), hydroxyproline content (61±8%, p=0.004) and myofibroblast counts (83±12%, p=0.002). Conclusions An inactivation gene strategy showed that DNAM-1 exerts profibrotic effects by controlling T cell activation and cytokine release. A molecular targeted strategy confirmed that DNAM-1 neutralising mAb has potent antifibrotic properties, supporting the hypothesis that inhibition of DNAM-1 might be a promising new approach for the treatment of SSc and potentially other related fibrotic diseases.
In prostate cancer the secreted form of clusterin (sCLU) has been described as an anti-apoptotic protein whose expression is increased after therapeutic intervention, whereas, the nuclear protein ...form nCLU was reported to have pro-apoptotic properties.
In order to provide new therapeutic approaches targeting CLU, we developed a strategy based on exon skipping by using a lentiviral construct to preferentially induce the nuclear spliced form of the protein. The molecular construct was transduced in LNCaP cells for testing the modulation of sensitivity of the transduced cells to pro-apoptotic stress.
We showed an increase of nCLU/sCLU expression ratio in the prostate cancer cell line "LNCaP" after lentiviral vector-U7 nCLU transduction. Moreover, we showed a significant inhibition of cell proliferation in nCLU-U7 LNCaP cells after treatment with cisplatin and after exposure to ionizing radiation compared to control cells. Finally, we showed that nCLU-U7 LNCaP cells exposure to UV-C significantly reduced an increase of cell death compared to control. Finally, we showed that modulating nCLU expression had profound impact on Ku70/Bax interaction as well as Rad17 expression which could be a key mechanism in sensitizing cells to cell death. In conclusion, this is the first report showing that increasing of nCLU/sCLU expression ratio by using an "on demand alternative splicing" strategy successfully increased sensitivity to radiotherapy and chemotherapy of prostate cancer cells.
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