Smoking and rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease caused by both genetic and environmental factors. Smoking has been implicated as one of the most important extrinsic risk factors for its development and severity. Recent developments have shed light on the pathophysiology of RA in smokers, including oxidative stress, inflammation, autoantibody formation and epigenetic changes. The association of smoking and the development of RA have been demonstrated through epidemiologic studies, as well as through in vivo and animal models of RA. With increased use of biological agents in addition to standard disease-modifying antirheumatic drugs (DMARDs), there has been interest in how smoking affects drug response in RA treatment. Recent evidence suggests the response and drug survival in people treated with anti-tumour necrosis factor (anti-TNF) therapy is poorer in heavy smokers, and possible immunological mechanisms for this effect are presented in the current paper.ope

Biofunctional nanofibrous substrate for local TNF-capturing as a strategy to control inflammation in arthritic joints

Rheumatoid arthritis (RA) is an autoimmune disease that affects the synovial cavity of joints, and its pathogenesis is associated with an increased expression of pro-inflammatory cytokines, namely tumour necrosis factor-alpha (TNF-α). It has been clinically shown to have an adequate response to systemic administration of TNF-α inhibitors, although with many shortcomings. To overcome such limitations, the immobilization of a TNF-α antibody on a nanofibrous substrate to promote a localized action is herein proposed. By using this approach, the antibody has its maximum therapeutic efficacy and a prolonged therapeutic benefit, avoiding the systemic side-effects associated with conventional biological agents’ therapies. To technically achieve such a purpose, the surface of electrospun nanofibers is initially activated and functionalized, allowing TNF-α antibody immobilization at a maximum concentration of 6 µg/mL. Experimental results evidence that the biofunctionalized nanofibrous substrate is effective in achieving a sustained capture of soluble TNF-α over time. Moreover, cell biology assays demonstrate that this system has no deleterious effect over human articular chondrocytes metabolism and activity. Therefore, the developed TNF-capturing system may represent a potential therapeutic approach for the local management of severely affected joints.This research was funded by the Portuguese Foundation for Science and Technology (FCT), namely the Post-doc fellowships of Marta Alves da Silva and Cristina Cunha (SFRH/BPD/73322/2010 and SFRH/BPD/96176/2013, respectively) and the Starting Investigator Grant of Agostinho Carvalho and Albino Martins (IF/00735/2014 and IF/00376/2014, respectively). It was also acknowledged the funded projects SPARTAN (PTDC/CTM-BIO/4388/2014) and FROnTHERA (NORTE-01-0145-FEDER-000023).info:eu-repo/semantics/publishedVersio

Obesity in chronic inflammation using rheumatoid arthritis as a model: definition, significance, and effects of physical activity & lifestyle

A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of PhilosophyBackground: Inflammation is the natural reaction of the body to an antigen. In some conditions, this reaction continues even after the elimination of the antigen, entering a chronic stage; it targets normal cells of the body and causes extensive damage. Rheumatoid arthritis (RA) is such a condition. It associates with significant metabolic alterations that lead to changes in body composition and especially body fat (BF) increases. In the general population, increased body fat (i.e. obesity) associates with a number of health disorders such as systemic low grade inflammation and a significantly increased risk for cardiovascular disease (CVD). Both effects of obesity could have detrimental effects in RA. Increased inflammation could worsen disease activity while obesity could further increase the already high CVD risk in RA. However, obesity in RA has attracted minimal scientific attention. Aims: The present project aimed to: 1) assess whether the existing measures of adiposity are able to identify the changes in body composition of RA patients, 2) if necessary develop RA-specific measures of adiposity, 3) investigate the association of obesity with disease characteristics and CVD profile of the patients, 4) and identify factors that might affect body weight and composition in these patients. Methods: A total of 1167 volunteers were assessed. Of them 43 suffered from osteoarthritis and 82 were healthy controls. These, together with 516 RA patients were used in the first study. Their body mass index (BMI), BF, and disease characteristics were assessed. In the second, third, fourth and fifth studies a separate set of 400 RA patients was assessed. In addition to the above assessments, their cardiovascular profile and more detailed disease characteristics were obtained. For the final study, 126 RA patients were assessed for all the above and also data on their physical activity levels and their diet were collected. Results: Assessments of adiposity for the general population are not valid for RA patients. Thus, we proposed RA-specific measures of adiposity. These are able to better identify RA patients with increased BF. We were also able to find associations between obesity and disease activity. Both underweight and obese RA patients had more active disease compared to normal-weight patients. Obese patients had significantly worse CVD profile compared to normal-weight. The newly devised measures of adiposity were able to identify those at increased risk. However, not all obese individuals were unhealthy and not all normal-weight healthy. Among our patients we were able to identify subtypes of obesity with distinct phenotypic characteristics that warrant special attention. Finally, we were able to identify factors that influence body weight and composition. Cigarette smoking protected against obesity while its cessation associated with increased adiposity. Physical activity was also found to be protective against obesity while diet or inflammation of the disease failed to produce any significant results. Conclusions: Obesity is a significant threat to the health of RA patients. The measures of adiposity developed herein should be used to identify obese RA patients. Physical activity seems like the sole mode for effective weight management in this population. Health and exercise professionals should actively encourage their patients to exercise as much as they can. This study has created more questions than it answered; further research in the association of obesity and inflammation, as well as in ways to treat it, is essential

Development of a novel Toll-like receptor-based two-hybrid assay for detecting protein-protein interactions and its application in the study of CD14 dimerization and FcyRIIA activation

Ph.DDOCTOR OF PHILOSOPH

Inflammatory diseases in mice lacking interleukin-1 receptor antagonist.

Available from British Library Document Supply Centre- DSC:DXN058657 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Electrospun Nanofibers for Biomedical Applications

Electrospinning is a versatile and effective technique widely used to manufacture nanofibrous structures from a diversity of materials (synthetic, natural or inorganic). The electrospun nanofibrous meshes’ composition, morphology, porosity, and surface functionality support the development of advanced solutions for many biomedical applications. The Special Issue on “Electrospun Nanofibers for Biomedical Applications” assembles a set of original and highly-innovative contributions showcasing advanced devices and therapies based on or involving electrospun meshes. It comprises 13 original research papers covering topics that span from biomaterial scaffolds’ structure and functionalization, nanocomposites, antibacterial nanofibrous systems, wound dressings, monitoring devices, electrical stimulation, bone tissue engineering to first-in-human clinical trials. This publication also includes four review papers focused on drug delivery and tissue engineering applications

Characterisation of T cell surface phenotype and effector function in a surrogate model of rheumatoid arthritis

TNFα plays a pivotal role in the pathogenesis of rheumatoid arthritis (RA), however the mechanisms underlying its dysregulation are not completely understood. TNFα production by macrophages is dependent on their contact with synovial T cells. In an in vitro model of RA, peripheral blood lymphocytes stimulated with a cocktail of cytokines mimic this RA T cell effector function. This thesis defines and characterises the effector population of cytokine-activated human T cells through two different approaches. Studies presented here show that within a population of cytokine-activated T cells, CD4+CD45RO+CCR7- cells induce the highest levels of TNFα when co-cultured with monocytes. Cytokine-activated CD4+ memory T cells phenotypically and functionally resemble lymphocytes isolated from RA synovial tissue. The cytokine cocktail induces proliferation and differentiation of peripheral blood T cells into highly potent effectors. These cells upregulate specific activation markers, adhesion molecules and chemokine receptors; such as CD25, CD69, CD62L, VLA-4, LFA-1 and CXCR4 which directly or indirectly, contribute to the induction of TNFα. By defining the phenotype of the lymphocytes most capable of inducing TNFα in our model, I isolated a population of T cells on which to focus my studies. The molecular nature of contact-dependent monocyte activation by cytokineactivated T cells was further investigated through proteomic profiling of the T cell surface. Plasma membrane protein-enriched samples were resolved in one- and two-dimensions. Subsequent mass spectrometry identified two molecules of interest. CD97 was found to be highly expressed by cytokine-activated CD4+ memory T cells, and contributed to both the induction of monocyte TNFα and spontaneous TNFα release from rheumatoid synovial tissue. Expression of CD81 and other tetraspanin family members increased on cytokine activation and was observed in synovial tissue. The results presented in this thesis provide further insight into the contribution of T cells in RA

Obesity in chronic inflammation using rheumatoid arthritis as a model : definition, significance, and effects of physical activity & lifestyle

Background: Inflammation is the natural reaction of the body to an antigen. In some conditions, this reaction continues even after the elimination of the antigen, entering a chronic stage; it targets normal cells of the body and causes extensive damage. Rheumatoid arthritis (RA) is such a condition. It associates with significant metabolic alterations that lead to changes in body composition and especially body fat (BF) increases. In the general population, increased body fat (i.e. obesity) associates with a number of health disorders such as systemic low grade inflammation and a significantly increased risk for cardiovascular disease (CVD). Both effects of obesity could have detrimental effects in RA. Increased inflammation could worsen disease activity while obesity could further increase the already high CVD risk in RA. However, obesity in RA has attracted minimal scientific attention. Aims: The present project aimed to: 1) assess whether the existing measures of adiposity are able to identify the changes in body composition of RA patients, 2) if necessary develop RA-specific measures of adiposity, 3) investigate the association of obesity with disease characteristics and CVD profile of the patients, 4) and identify factors that might affect body weight and composition in these patients. Methods: A total of 1167 volunteers were assessed. Of them 43 suffered from osteoarthritis and 82 were healthy controls. These, together with 516 RA patients were used in the first study. Their body mass index (BMI), BF, and disease characteristics were assessed. In the second, third, fourth and fifth studies a separate set of 400 RA patients was assessed. In addition to the above assessments, their cardiovascular profile and more detailed disease characteristics were obtained. For the final study, 126 RA patients were assessed for all the above and also data on their physical activity levels and their diet were collected. Results: Assessments of adiposity for the general population are not valid for RA patients. Thus, we proposed RA-specific measures of adiposity. These are able to better identify RA patients with increased BF. We were also able to find associations between obesity and disease activity. Both underweight and obese RA patients had more active disease compared to normal-weight patients. Obese patients had significantly worse CVD profile compared to normal-weight. The newly devised measures of adiposity were able to identify those at increased risk. However, not all obese individuals were unhealthy and not all normal-weight healthy. Among our patients we were able to identify subtypes of obesity with distinct phenotypic characteristics that warrant special attention. Finally, we were able to identify factors that influence body weight and composition. Cigarette smoking protected against obesity while its cessation associated with increased adiposity. Physical activity was also found to be protective against obesity while diet or inflammation of the disease failed to produce any significant results. Conclusions: Obesity is a significant threat to the health of RA patients. The measures of adiposity developed herein should be used to identify obese RA patients. Physical activity seems like the sole mode for effective weight management in this population. Health and exercise professionals should actively encourage their patients to exercise as much as they can. This study has created more questions than it answered; further research in the association of obesity and inflammation, as well as in ways to treat it, is essential.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The interleukin 1 gene family in systemic juvenile idiopathic arthritis

Patients with systemic Juvenile Idiopathic Arthritis (sJIA) have elevated serum levels of inflammatory cytokines. Treatment with interleukin-1 (IL-1) receptor antagonist (Anakinra) shows remarkable improvement in some sJIA patients. The hypothesis of this thesis is that genetic variations in IL-1 family genes contribute to disease pathogenesis. To investigate this, a two-stage case-control association study of 20 candidate genes was performed. Selected tagging SNPs were tested for association in 130 sJIA patients and 146 controls in stage-1 of the study. SNPs at significantly different frequencies in the cohorts were genotyped in an additional 105 sJIA patients and 184 controls, and stratified metaanalysis of the two-stage data performed. Analysis was also performed with 4,671 controls from the Wellcome Trust Case Control Consortium (WTCCC). No associations were found with caspase-1, cryopyrin, or IL-18. Significant disease associations were identified with SNPs in the ligand IL1A, the receptor antagonist IL1RN, and a two-SNP haplotype in the IL-18 antagonist IL18BP. Associations were also identified in the decoy receptor IL1R2, and the co-receptor IL1RAP, although these were not confirmed when re-analysed with the WTCCC controls. Transient transfection assays with haplotype constructs, performed by Dr Wen, showed that the IL18BP haplotype affected gene transcription levels in vitro. This effect was not however reproduced using PBMCs from healthy individuals. Allele specific binding to one of the haplotype SNPs was predicted in silico, but no evidence for this was seen in EMSA experiments. Further functional studies are required to corroborate involvement of this haplotype in disease. In summary, this study has identified genetic associations for susceptibility to sJIA with a number of IL1 family members. These results indicate that there may be aberrant control of IL-1 activity in patients with sJIA. Further work is required to determine how these associated SNPs affect IL-1 activity, and thereby the inflammatory response in sJIA