Integrins are heterodimeric (α, β) cell adhesion receptors. We demonstrate that point mutations in the cytoplasmic domains of both the α and β subunits promote constitutive signaling by the integrin αβ. By generating charge reversal mutations, we show these “activating” mutations may act by disrupting a potential salt bridge between the membrane-proximal portions of the α and β subunit cytoplasmic domains. Thus, the modulation of specific interactions between the α and β subunit cytoplasmic domains may regulate transmembrane signaling through integrins. In addition, these activating mutations induce dominant alterations in cellular behavior, such as the assembly of the extracellular matrix. Consequently, somatic mutations in integrin cytoplasmic domains could have profound effects in vivo on integrin-dependent functions such as matrix assembly, cell migration, and anchorage-dependent cell growth and survival.

Objectives To evaluate the safety and tolerability of the intravenous administration of Cx611, a preparation of allogeneic expanded adipose-derived stem cells (eASCs), in patients with refractory rheumatoid arthritis (RA), as well as to obtain preliminary clinical efficacy data in this population. Methods It is a multicentre, dose escalation, randomised, single-blind (double-blind for efficacy), placebo-controlled, phase Ib/IIa clinical trial. Patients with active refractory RA (failure to at least two biologicals) were randomised to receive three intravenous infusions of Cx611: 1 million/kg (cohort A), 2 million/kg (cohort B), 4 million/kg (cohort C) or placebo, on days 1, 8 and 15, and they were followed for therapy assessment for 24 weeks. Results Fifty-three patients were treated (20 in cohort A, 20 in cohort B, 6 in cohort C and 7 in placebo group). A total of 141 adverse events (AEs) were reported. Seventeen patients from the group A (85%), 15 from the group B (75%), 6 from the group C (100%) and 4 from the placebo group (57%) experienced at least one AE. Eight AEs from 6 patients were grade 3 in intensity (severe), 5 in cohort A (lacunar infarction, diarrhoea, tendon rupture, rheumatoid nodule and arthritis), 2 in cohort B (sciatica and RA) and 1 in the placebo group (asthenia). Only one of the grade 3 AEs was serious (the lacunar infarction). American College of Rheumatology 20 responses for cohorts A, B, C and placebo were 45%, 20%, 33% and 29%, respectively, at month 1, and 25%, 15%, 17% and 0%, respectively, at month 3. Conclusions The intravenous infusion of Cx611 was in general well tolerated, without evidence of dose-related toxicity at the dose range and time period studied. In addition, a trend for clinical efficacy was observed. These data, in our opinion, justify further investigation of this innovative therapy in patients with RA. Trial registration numbers EudraCT: 2010-021602-37; NCT01663116; Results.

The aim of this study was to determine, through a genome-wide association study (GWAS), the genetic components contributing to different clinical sub-phenotypes of systemic sclerosis (SSc). We considered limited (lcSSc) and diffuse (dcSSc) cutaneous involvement, and the relationships with presence of the SSc-specific auto-antibodies, anti-centromere (ACA), and anti-topoisomerase I (ATA). Four GWAS cohorts, comprising 2,296 SSc patients and 5,171 healthy controls, were meta-analyzed looking for associations in the selected subgroups. Eighteen polymorphisms were further tested in nine independent cohorts comprising an additional 3,175 SSc patients and 4,971 controls. Conditional analysis for associated SNPs in the HLA region was performed to explore their independent association in antibody subgroups. Overall analysis showed that non-HLA polymorphism rs11642873 in IRF8 gene to be associated at GWAS level with lcSSc (P = 2.32×10⁻¹², OR = 0.75). Also, rs12540874 in GRB10 gene (P = 1.27 × 10⁻⁶, OR = 1.15) and rs11047102 in SOX5 gene (P = 1.39×10⁻⁷, OR = 1.36) showed a suggestive association with lcSSc and ACA subgroups respectively. In the HLA region, we observed highly associated allelic combinations in the HLA-DQB1 locus with ACA (P = 1.79×10⁻⁶¹, OR = 2.48), in the HLA-DPA1/B1 loci with ATA (P = 4.57×10⁻⁷⁶, OR = 8.84), and in NOTCH4 with ACA P = 8.84×10⁻²¹, OR = 0.55) and ATA (P = 1.14×10⁻⁸, OR = 0.54). We have identified three new non-HLA genes (IRF8, GRB10, and SOX5) associated with SSc clinical and auto-antibody subgroups. Within the HLA region, HLA-DQB1, HLA-DPA1/B1, and NOTCH4 associations with SSc are likely confined to specific auto-antibodies. These data emphasize the differential genetic components of subphenotypes of SSc. Scleroderma or systemic sclerosis is a complex autoimmune disease affecting one individual of every 100,000 in Caucasian populations. Even though current genetic studies have led to better understanding of the pathogenesis of the disease, much remains unknown. Scleroderma is a heterogeneous disease, which can be subdivided according to different criteria, such as the involvement of organs and the presence of specific autoantibodies. Such subgroups present more homogeneous genetic groups, and some genetic associations with these manifestations have already been described. Through reanalysis of a genome-wide association study data, we identify three novel genes containing genetic variations which predispose to subphenotypes of the disease (IRF8, GRB10, and SOX5). Also, we better characterize the patterns of associated loci found in the HLA region. Together, our findings lead to a better understanding of the genetic component of scleroderma.

Objective Apremilast, an oral phosphodiesterase 4 inhibitor, downregulates intracellular inflammatory mediator synthesis by elevating cyclic adenosine monophosphate levels. The PALACE 2 trial evaluated apremilast efficacy and safety in patients with active psoriatic arthritis (PsA) despite prior conventional disease-modifying antirheumatic drugs and/or biologic therapy. Methods Eligible patients were randomized (1:1:1) to placebo, apremilast 20 mg BID, or apremilast 30 mg BID. At Week 16, patients with swollen and tender joint count improvement < 20% entered early escape, with placebo patients rerandomized (1:1) to apremilast 20 mg BID or 30 mg BID while apremilast patients continued on their initial apremilast dose. At Week 24, patients remaining on placebo were rerandomized to apremilast 20 mg BID or 30 mg BID. The primary endpoint was the proportion of patients achieving > 20% improvement in American College of Rheumatology response criteria (ACR20) at Week 16. Results In the intent-to-treat population (N = 484), ACR20 at Week 16 was achieved by more patients receiving apremilast 20 mg BID [37.4% (p = 0.0002)] and 30 mg BID [32.1% (p = 0.0060)] versus placebo (18.9%). Clinically meaningful improvements in signs and symptoms of PsA, physical function, and psoriasis were observed with apremilast through Week 52. The most common adverse events were diarrhea, nausea, headache, and upper respiratory tract infection. Diarrhea and nausea generally occurred early and usually resolved spontaneously with continued treatment. Laboratory abnormalities were infrequent and transient. Conclusion Apremilast demonstrated clinical improvements in PsA for up to 52 weeks, including signs and symptoms, physical function, and psoriasis. No new safety signals were observed. ClinicalTrials.gov identifier: NCT01212757.

Objective: To explore the potential involvement of the chemokine system in synoviocyte‐mediated tissue destruction in rheumatoid arthritis (RA), we studied the expression profile of chemokine receptors and their function in the migration, proliferation, and matrix metalloproteinase (MMP) production of cultured fibroblast‐like synoviocytes (FLS) from RA patients.Methods: The presence of CC and CXC chemokine receptors on cultured FLS was studied at the messenger RNA (mRNA) level by reverse transcriptase–polymerase chain reaction and at the cell surface expression level by flow cytometry. Variations in cytosolic calcium influx induced by chemokine stimulation were assessed by flow cytometry on Fura Red–preloaded FLS. Two‐compartment transwell chambers were used for FLS chemotaxis assays. Cell growth was measured by a fluorescence‐based proliferation assay. Gelatinase and collagenase activities were determined by a fibril degradation assay and zymography.Results: FLS constitutively expressed the receptors CCR2, CCR5, CXCR3, and CXCR4, both at the cell surface and mRNA levels, but failed to express CCR3 and CCR6. Significant intracytosolic calcium influx was observed on FLS challenged with monocyte chemotactic protein 1 (MCP‐1), stromal cell–derived factor 1α (SDF‐1α), and interferon‐inducible protein 10 (IP‐10). Stimulation with MCP‐1, SDF‐1α, IP‐10, and monokine induced by interferon‐γ enhanced the migration and proliferation of FLS. These chemokines, in addition to RANTES, increased in a dose‐ and time‐dependent manner the gelatinase and collagenase activities in cell‐free supernatants of cultured FLS. Interestingly, the chemokine‐mediated up‐regulation of MMP activities was significantly abrogated by the presence of anti–interleukin‐1β, but not anti–tumor necrosis factor α, blocking antibodies.Conclusion: These data suggest that through modulation of the migration, proliferation, and MMP production by FLS, the chemokine system may play a more direct role in the destructive phase of RA than is currently suspected, and thus emphasize the relevance of chemokines and their receptors as potential therapeutic targets in this disease.