185 research outputs found
Mapping the interaction of B cell Leukemia 3 (BCL-3) and nuclear factor κB (NF-κB) p50 identifies a BCL-3-mimetic anti-inflammatory peptide
The NF-κB transcriptional response is tightly regulated by a number of processes including the phosphorylation, ubiquitination, and subsequent proteasomal degradation of NF-κB subunits. The IκB family protein BCL-3 stabilizes a NF-κB p50 homodimer·DNA complex through inhibition of p50 ubiquitination. This complex inhibits the binding of the transcriptionally active NF-κB subunits p65 and c-Rel on the promoters of NF-κB target genes and functions to suppress inflammatory gene expression. We have previously shown that the direct interaction between p50 and BCL-3 is required for BCL-3-mediated inhibition of pro-inflammatory gene expression. In this study we have used immobilized peptide array technology to define regions of BCl-3 that mediate interaction with p50 homodimers. Our data show that BCL-3 makes extensive contacts with p50 homodimers and in particular with ankyrin repeats (ANK) 1, 6, and 7, and the N-terminal region of Bcl-3. Using these data we have designed a BCL-3 mimetic peptide based on a region of the ANK1 of BCL-3 that interacts with p50 and shares low sequence similarity with other IκB proteins. When fused to a cargo carrying peptide sequence this BCL-3-derived peptide, but not a mutated peptide, inhibited Toll-like receptor-induced cytokine expression in vitro. The BCL-3 mimetic peptide was also effective in preventing inflammation in vivo in the carrageenan-induced paw edema mouse model. This study demonstrates that therapeutic strategies aimed at mimicking the functional activity of BCL-3 may be effective in the treatment of inflammatory disease
Disease activity flares and pain flares in an early rheumatoid arthritis inception cohort; characteristics, antecedents and sequelae
© 2019 The Author(s). This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: RA flares are common and disabling. They are described in terms of worsening inflammation but pain and inflammation are often discordant. To inform treatment decisions, we investigated whether inflammatory and pain flares are discrete entities. Methods: People from the Early RA Network (ERAN) cohort were assessed annually up to 11 years after presentation (n = 719, 3703 person-years of follow up). Flare events were defined in 2 different ways that were analysed in parallel; DAS28 or Pain Flares. DAS28 Flares satisfied OMERACT flare criteria of increases in DAS28 since the previous assessment (≥1.2 points if active RA or ≥ 0.6 points if inactive RA). A ≥ 4.8-point worsening of SF36-Bodily Pain score defined Pain Flares. The first documented episode of each of DAS28 and Pain Flare in each person was analysed. Subgroups within DAS28 and Pain Flares were determined using Latent Class Analysis. Clinical course was compared between flare subgroups. Results: DAS28 (45%) and Pain Flares (52%) were each common but usually discordant, with 60% of participants in DAS28 Flare not concurrently in Pain Flare, and 64% of those in Pain Flare not concurrently in DAS28 Flare. Three discrete DAS28 Flare subgroups were identified. One was characterised by increases in tender/swollen joint counts (14.4%), a second by increases in symptoms (13.1%), and a third displayed lower flare severity (72.5%). Two discrete Pain Flare subgroups were identified. One occurred following low disease activity and symptoms (88.6%), and the other occurred on the background of ongoing active disease and pain (11.4%). Despite the observed differences between DAS28 and Pain Flares, each was associated with increased disability which persisted beyond the flare episode. Conclusion: Flares are both common and heterogeneous in people with RA. Furthermore our findings indicate that for some patients there is a discordance between inflammation and pain in flare events. This discrete flare subgroups might reflect different underlying inflammation and pain mechanisms. Treatments addressing different mechanisms might be required to reduce persistent disability after DAS28 and Pain Flares.Peer reviewedFinal Published versio
Discrete trajectories of resolving and persistent pain in people with rheumatoid arthritis despite undergoing treatment for inflammation: results from three UK cohorts
Rheumatoid arthritis (RA) is an example of human chronic inflammatory pain. Modern treatments suppress inflammation, yet pain remains a major problem for many people with RA. We hypothesised that discrete RA subgroups might display favourable or unfavourable pain trajectories when receiving treatment, and that baseline characteristics will predict trajectory allocation.Growth Mixture Modelling was used to identify discrete trajectories of SF36-Bodily Pain scores during 3 years in 3 RA cohorts (Early RA Network (ERAN); n=683, British Society for Rheumatology Biologics Register Biologics (n=7090) and Non-Biologics (n=1720) cohorts. Logistic regression compared baseline predictor variables between trajectories. The role of inflammation was examined in a subgroup analysis of people with normal levels of inflammatory markers after 3 years.Mean SF36-Bodily Pain scores in each cohort improved but remained throughout 3y follow up >1 SD worse than the UK general population average. Discrete Persistent Pain (59% to 79% of cohort participants) and Resolving Pain (19% to 27%) trajectories were identified in each cohort. In ERAN, a third trajectory displaying persistently Low Pain (23%) was also identified. In people with normal levels of inflammatory markers after 3 years, 65% of them were found to follow a Persistent Pain trajectory. When trajectories were compared, greater disability (aORs 2.3-2.5 per unit baseline Health Assessment Questionnaire score) and smoking history (aORs 1.6-1.8) were risk factors for Persistent Pain trajectories in each cohort.In conclusion, distinct trajectories indicate patient subgroups with very different pain prognosis during RA treatment. Inflammation does not fully explain the pain trajectories, and non-inflammatory factors as well as acute phase response predict which trajectory an individual will follow. Targeted treatments additional to those which suppress inflammation might reduce the long term burden of arthritis pain
HDAC1 interacts with the p50 NF-κB subunit via its nuclear localization sequence to constrain inflammatory gene expression
The NF-κB p50 subunit is an important regulator of inflammation, with recent experimental evidence to support it also having a tumor suppressor role. Classically, p50 functions in heterodimeric form with the RelA (p65) NF-κB subunit to activate inflammatory genes. However, p50 also forms homodimers which actively repress NF-κB-dependent inflammatory gene expression and exert an important brake on the inflammatory process. This repressive activity of p50:p50 is thought to be in part mediated by an interaction with the epigenetic repressor protein Histone Deacetylase 1 (HDAC1). However, neither the interaction of p50 with HDAC1 nor the requirement of HDAC1 for the repressive activities of p50 has been well defined. Here we employed in silico prediction with in vitro assays to map sites of interaction of HDAC1 on the p50 protein. Directed mutagenesis of one such region resulted in almost complete loss of HDAC1 binding to p50. Transfected mutant p50 protein lacking the putative HDAC1 docking motif resulted in enhanced cytokine and chemokine expression when compared with cells expressing a transfected wild type p50. In addition, expression of this mutant p50 was associated with enhanced chemoattraction of neutrophils and acetylation of known inflammatory genes demonstrating the likely importance of the p50:HDAC1 interaction for controlling inflammation. These new insights provide an advance on current knowledge of the mechanisms by which NF-κB-dependent gene transcription are regulated and highlight the potential for manipulation of p50:HDAC1 interactions to bring about experimental modulation of chronic inflammation and pathologies associated with dysregulated neutrophil accumulation and activation
General practitioners’ perspectives on campaigns to promote rapid help-seeking behaviour at the onset of rheumatoid arthritis
Objective. To explore general practitioners’ (GPs’ ) perspectives on public health campaigns to encourage people with the early symptoms of rheumatoid arthritis (RA) to seek medical help rapidly. Design. Nineteen GPs participated in four semistructured focus groups. Focus groups were audio-recorded, transcribed verbatim, and analysed using thematic analysis. Results. GPs recognised the need for the early treatment of RA and identified that facilitating appropriate access to care was important. However, not all held the view that a delay in help seeking was a clinically significant issue. Furthermore, many were concerned that the early symptoms of RA were often non-specific, and that current knowledge about the nature of symptoms at disease onset was inadequate to inform the content of a help-seeking campaign. They argued that a campaign might not be able to specifically target those who need to present urgently. Poorly designed campaigns were suggested to have a negative impact on GPs’ workloads, and would “clog up” the referral pathway for genuine cases of RA. Conclusions. GPs were supportive of strategies to improve access to Rheumatological care and increase public awareness of RA symptoms. However, they have identified important issues that need to be considered in developing a public health campaign that forms part of an overall strategy to reduce time to treatment for patients with new onset RA. This study highlights the value of gaining GPs’ perspectives before launching health promotion campaigns
Reductions in radiographic progression in early RA over 25-years: changing contribution from RF in 2 multi-centre UK inception cohorts
Objectives: To assess 5-year progression of erosions and Joint Space Narrowing (JSN), and their associations with RF status in two large, multi-centre early-RA cohorts spanning 25-years.
Methods: Radiographic joint damage was recorded using the Sharp/van der Heijde (SvdH) method in the Early RA Study (ERAS) 1986-2001, and the Early RA Network (ERAN) 2002-2013. Mixed-effects negative-binomial regression estimated changes in radiographic damage over 5-years, including erosions and JSN separately. Rheumatoid Factor (RF), along with age, sex and baseline markers of disease activity were controlled for.
Results: 1,216 patients from ERAS and 446 from ERAN had radiographic data. Compared to ERAS, ERAN patients had a lower mean total SvdH score at baseline (ERAN=6.2 vs. ERAS=10.5, p<0.001), and mean annual rate of change (ERAN=2.5 vs. ERAS=6.9 per year, p<0.001). 74% of ERAS and 27% of ERAN patients progressed ≥5 units. Lower scores at baseline in ERAN were largely driven by reductions in JSN (ERAS=3.9 vs. ERAN=1.2, p<0.001), along with erosions (ERAS=1.9 vs. ERAN=0.8, p<0.001). RF was associated with greater progression in each cohort, but the absolute difference in mean annual rate of change for RF positive patients was substantially higher for ERAS (RF+= 8.6 vs. RF-= 5.1, p<0.001), relative to ERAN (RF+= 2.0 vs. RF-= 1.9, p=0.855).
Conclusion: Radiographic progression has significantly reduced between the two cohorts, associated with lower baseline damage and other factors, including changes in early DMARD use. The impact of RF status as a prognostic marker of clinically meaningful change in radiographic progression has markedly diminished in the context of more modern treatment. This article is protected by copyright. All rights reserved
RACK(1) to the future - a historical perspective
Abstract This perspective summarises the first and long overdue RACK1 meeting held at the University of Limerick, Ireland, May 2013, in which RACK1's role in the immune system, the heart and the brain were discussed and its contribution to disease states such as cancer, cardiac hypertrophy and addiction were described. RACK1 is a scaffolding protein and a member of the WD repeat family of proteins. These proteins have a unique architectural assembly that facilitates protein anchoring and the stabilisation of protein activity. A large body of evidence is accumulating which is helping to define the versatile role of RACK1 in assembling and dismantling complex signaling pathways from the cell membrane to the nucleus in health and disease. In this commentary, we first provide a historical perspective on RACK1. We also address many of the pertinent and topical questions about this protein such as its role in transcription, epigenetics and translation, its cytoskeletal contribution and the merits of targeting RACK1 in disease. Historical perspective It has been 20 years since RACK1 was cloned as the first identified binding protein for Protein Kinase C (PKC), and the road the Mochly-Rosen group took toward its discovery was not trivial. The role of scaffolding proteins in the temporal and spatial regulation of signal transduction seems obvious today, however, this was not the case in the late 1980s when Prof. Daria Mochly-Rosen developed the hypothesis that anchoring/scaffolding proteins control the specificity of substrate phosphorylation and function of Protein Kinase C (PKC) isozymes. An alpha phage display library/overlay assay strategy was used to identify binding proteins that interact with active PKC isoforms. To this day Dr. Ron remembers when one gene product was identified and was termed RACK1 for Receptor for Activated C Kinase RACK1 as a scaffolding protein The conserved seven blade propeller structure of RACK1 facilitates the folding order into constituent propeller blades. These propeller blades are intrinsic to RACK1's protein binding capacity and allow RACK1 to function as a signaling hub RACK1: a scaffolding protein with a central role in transcription, epigenetics & translation RACK1 has a strong effect on transcription and translation by acting at critical points; principally the ribosomal small subunit and via nuclear translocation and regulation of chromatin and transcriptional complexes RACK1 and cytoskeletal proteins: a new frontier The cellular cytoskeleton, whose major components comprise of actin, microtubules and intermediate filaments, maintains cellular integrity and regulates multiple cellular functions including migration RACK1 as a potential therapeutic target As the number of binding partners and validated cellular functions for RACK1 has increased, so has its link with an array of disease states [38] are amongst the first describing beta-propeller/small molecule complexes. Interestingly, the report by Senisterra et al. Concluding comments There are, of course, numerous remaining questions that are of great interest. For example, how can one protein play such an important role in many and diverse biological functions? Is it possible that a number of RACK1 binding partners share common binding sites on RACK1? Is RACK1 function and/or expression levels regulated by posttranslational modifications such as phosphorylation, sumoylation and ubiquitination? Does RACK1 contribute to a large number of disease states and can RACK1 be used as a target for drug development? These are exciting times for RACK1 biologists. As more and more research areas converge on RACK1, we can expect answers to these questions to unfold. RACK1 biology would benefit greatly from detailed mechanistic mathematical modelling and quantitative experimentation to help us comprehend how RACK1 functions in systems biology, beyond its role as a scaffolding protein. We look forward to the next RACK1 conference, which we have no doubt will bring more exciting new data on the role of our favorite protein in cellular functions
Validation of methods for converting the original Disease Activity Score (DAS) to the DAS28
© The Author(s) 2018.The Disease Activity Score (DAS) is integral in tailoring the clinical management of rheumatoid arthritis (RA) patients and is an important measure in clinical research. Different versions have been developed over the years to improve reliability and ease of use. Combining the original DAS and the newer DAS28 data in both contemporary and historical studies is important for both primary and secondary data analyses. As such, a methodologically robust means of converting the old DAS to the new DAS28 measure would be invaluable. Using data from The Early RA Study (ERAS), a sub-sample of patients with both DAS and DAS28 data were used to develop new regression imputation formulas using the total DAS score (univariate), and using the separate components of the DAS score (multivariate). DAS were transformed to DAS28 using an existing formula quoted in the literature, and the newly developed formulas. Bland and Altman plots were used to compare the transformed DAS with the recorded DAS28 to ascertain levels of agreement. The current transformation formula tended to overestimate the true DAS28 score, particularly at the higher end of the scale. A formula which uses all separate components of the DAS was found to estimate the scores with a higher level of precision. A new formula is proposed that can be used by other early RA cohorts to convert the original DAS to DAS28.Peer reviewedFinal Published versio
Secular changes in the progression of clinical markers and patient-reported outcomes in early rheumatoid arthritis
© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.OBJECTIVES: To examine secular trends in the progression of clinical and patient-reported outcomes in early RA. METHODS: A total of 2701 patients recruited to the Early Rheumatoid Arthritis Study or Early Rheumatoid Arthritis Network with year of diagnosis from 1986 to 2011. The 5-year progression rates for patients diagnosed at different points in time were modelled using mixed-effects regression; 1990, 2002 and 2010, were compared. Clinical markers of disease included the 28-joint count DAS and the ESR. Patient-reported markers included the HAQ, visual analogue scale of pain and global health, and the Short-Form 36. RESULTS: Statistically significant improvements in both 28-joint count DAS and ESR were seen over the 5 years in patients diagnosed with RA compared with those diagnosed earlier. By 5 years, 59% of patients with diagnosis in 2010 were estimated to reach low disease activity compared with 48% with diagnosis in 2002 and 32% with diagnosis in 1990. Whilst HAQ demonstrated statistically significant improvements, these improvements were small, with similar proportions of patients achieving HAQ scores of ≤1.0 by 5 years with a diagnosis in 1990 compared with 2010. Levels of the visual analogue scale and the Mental Component Scores of the Short-Form 36 indicated similar, statistically non-significant levels over the 5 years, irrespective of year diagnosed. CONCLUSION: This study demonstrates improvements in inflammatory markers over time in early RA, in line with improved treatment strategies. These have not translated into similar improvements in patient-reported outcomes relating to either physical or mental health.Peer reviewedFinal Published versio
- …