Thesis (M.A.) / Systemic sclerosis (SSc) is a clinically heterogenous chronic fibrotic disease which affects skin and internal organs. While the pathogenesis of SSc remains unknown, the hallmark of both localized and diffuse SSc in the skin is the replacement of normal dermal architecture with excessive deposition of collagen and other connective tissue macromolecules. Progressive replacement of tissue architecture by collagen-rich extracellular matrix (ECM) results in functional impairment of affected organs. Fibrotic damage to these affected organs accounts for much of the morbidity and mortality concomitant with SSc, particularly in the lungs. Myofibroblasts are the primary ECM-secreting cells during wound healing and fibrosis. Myocardin-related transcription factor A (MRTF-A), is an important regulator of myofibroblast differentiation, depending on serum response factor (SRF) for smooth muscle actin (SMA) and Sp1 in the regulation of collagen gene expression. MRTF-A continually shuttles between the nucleus and cytoplasm in unstimulated cells. Signals of stress, mechanical force, and migration control MRTF-A movement by a mechanism in which Rho-activated cytoskeletal actin polymerization induces its relocation from the cytoplasm to the nucleus. The major hypothesis in this thesis is that MRTF-A is dysregulated (impairment of a physiological regulatory mechanisms) and/or activated in SSc patients in part through transforming growth factor beta (TGF-β). To test this hypothesis, immunohistochemistry using MRTF-A antibodies was performed on SSc patient skin lesions and healthy control skin. Staining was observed in the epidermis, epidermal structures, vasculature and dermis of SSc and healthy control skin. In the epidermal layer of patients with SSc, there was significantly more nuclear localization of MRTF-A then in normal controls. Prominent staining is also present in endothelial, perivascular and some perivascular inflammatory cells of SSc patients. Perivascular staining was not seen in healthy controls. Interestingly, there was some accumulation of nuclear MRTF-A in areas typical of myofibroblasts in SSc skin, but this staining is not as striking as vascular staining. TGF-β activates MRTF-A in a cell-specific manner. As SSc typically begins within the skin, human dermal fibroblasts (HDF) were grown in culture. HDFs synthesize and secrete collagen to a greater extent when compared to human lung fibroblasts (IMR90 cells). Treatment with TGF-β enhances cytoplasmic localization of MRTF-A at 4-8 hours in HDFs and prolongs nuclear localization. Transgenic mouse lung cells were isolated from an MRTF-A loss-of-function mouse carrying the 3.6 kb proximal promoter of the rat COL1A1 gene driving topaz green fluorescent protein (GFP) (pOB3.6COLGFPtpz). Since angiotensin II (ANG II) may enhance TGF-β response or collagen transcription directly, wild type (WT) and MRTF-A knockout (KO) cells were treated with ANG II and TGF-β. Quantification of collagen transcription by GFP fluorescence and protein synthesis by Western and secretion by Sircol analysis revealed collagen gene expression is consistently lower in KO fibroblasts compared to WT. Total percentage of fluorescent KO cells were consistently lower in comparison to WT cells as well. KO cells do not respond to TGF-β or ANG II treatment, whereas TGF-β increased collagen gene expression by WT cells, but not KO cells. Furthermore, treatment with ANG II did not up-regulate transcription in WT mouse lung fibroblasts. However, TGF-β receptor kinase 1 (TβR-1) inhibitor SB431542 attenuated collagen transcription in both WT and KO fibroblasts regardless of treatment suggesting that the receptor is active with or without MRTF-A possibly with an endogenous ligand produced by these cells. The activation of MRTF-A is an important protein regulating collagen synthesis and may potentially serve as a therapeutic target in future treatments of fibrotic disease such as SSc.

No description available.

Background: Malnutrition and gastrointestinal (GI) involvement are common in patients with systemic sclerosis (SSc). Despite malnutrition being common, little is known about its associations and predictors. Although patients are frequently screened and assessed for malnutrition, different clinically applicable assessment modalities in SSc have not been compared. An understanding of the relationship between dietary intake and energy expenditure is important for nutritional assessment and management. However, studies have not compared these. For many years, home parenteral nutrition (HPN) has been used in patients with intestinal failure, but little outcome data exists to support its role in SSc. GI involvement results in dysmotility, the underlying mechanism for the development of which is unknown. However, autonomic dysfunction has been proposed. Aims: To explore aspects of the nutritional assessment and management of patients with SSc. To seek associations and predictors of nutritional decline. To investigate for a link between GI dysmotility and autonomic dysfunction. Methods: Study 1: A retrospective review of the survival and outcome data of patients commenced on HPN over 22 years. Study 2: An assessment of 168 patients recruited over 12 months and restudied after approximately 1 year. Assessment included demographics, clinical data, GI and functional questionnaires, nutrition screening tool, oral aperture, mid-upper arm and 4-site anthropometry, bioelectrical impedance and biochemical testing. Re-study included weight change. Study 3: A 3 day assessment of dietary intake and energy expenditure using food record charts and SenseWear® Armband involving 36 patients recruited to Study 2. Study 4: Patients and matched controls completed GI and autonomic questionnaires, an autonomic battery, a gastric emptying study and postprandial cardiovascular measures and GI sensations and symptoms scores. Results: Study 1: The cumulative probabilities of surviving on HPN at 2, 5 and 10 years were 75%, 37% and 23%. HPN-associated complication rates were low. Study 2: Nutritional screening failed to identify all patients who lost weight. Mid-arm circumference correlated with body mass index (BMI) and weight change. Four-site anthropometry correlated with BMI more strongly (r=0.65 vs. r=0.49) than bioelectrical impedance analysis. Small intestinal, but not oesophageal, involvement correlated with baseline nutritional status. No clear predictors of nutritional decline were identified. Study 3: Predicted energy intakes correlated with measured expenditures, but absolute values differed. Energy intakes did not correlate with expenditures. Study 4: Autonomic measures did not correlate with gastric emptying. However, autonomic results were hindered by patient-related and technical limitations. Conclusion: Nutritional screening tools cannot be relied upon to detect all at risk patients. MAC and 4-site anthropometry may have a role in nutritional assessment. When an accurate appreciation of energy requirements is needed, kinematic monitors should be used rather than predictive equations. For those patients who progress to intestinal failure, HPN is safe and effective. Autonomic studies were inconclusive. However, the autonomic apparatus has been refined for utilisation in more definitive studies in younger patients.

Interstitial lung disease is one of the main causes of mortality in Systemic Sclerosis. The course of the disease is clinically variable where patients can suffer from a range of stable disease to rapid progressive clinical deterioration. Therefore, it is important to identify biomarkers that can predict the clinical course of patients in order to provide early treatment. We evaluated 1129 proteins utilizing novel high-throughput SOMAlogic proteomic technology from the serum of 13 LSSc, 13 progressive ILD and 11 stable ILD patients. Calpain-1 was significantly elevated in progressive ILD patients (median 15129 RFU, 11091-24561) compared to LSSc patients (12759, 9904-15498, p=0.0015) and stable ILD patients (11876, 10271-14249, p=0.0005). Coagulation Factor V was significantly lower in the progressive ILD patients (7161 RFU, 2140-8296) compared to LSSc patients (10311 RFU, 6396-12260, p=0.001) and stable ILD patients (9646 RFU, 6510-11941, p=0.0016). The combination of Coagulation Factor V and Calpain-1 produced an area under the curve of 0.97 (95% CI, 0.921-0.99), sensitivity of 99% and specificity of 91% for the identification of progressive ILD. We have identified a combination of proteins that show potential to be prognostic biomarkers for ILD in SSc. / 2016-12-31T00:00:00Z

Background: Systemic sclerosis (SSc) is an autoimmune disease associated with significant mortality and morbidity. Cardiovascular causes are the single largest contributor to premature death. To date, much of the focus on managing the care of SSc patients has concentrated on traditional risk factors related to fibrotic and microvascular dysfunction. There is, however, evidence of a strong cardiovascular component to the disease and points to macrovascular dysfunction as being a key contributor to the premature mortality associated with SSc. This thesis reports on the conduct of a multi-centre, randomised, placebo-controlled clinical trial (the SSTEP Study). The aim of the study was to assess whether oral Iloprost was more effective than placebo in reducing cardiovascular events and disease progression in SSc. Methods: Two hundred and sixteen patients with systemic sclerosis were recruited, between February 2002 and February 2005, at nine centres in the UK and Ireland. After one month placebo run-in, participants were randomised to either oral Iloprost (50-200mcg daily) or matched placebo. Baseline demographics, disease characteristics and organ screening data were collected, and participants were reviewed annually for endpoint measurements; CV events, SSc disease progression and mortality, with regular safety reviews between these annual visits. Participants were followed up for a period of 4 to 7 years. Results: Data analysis of the combination of the two measures (survival free from death or a cardiovascular event) demonstrated a trend towards favouring Iloprost over placebo but the difference was not statistically significant (Logrank test: Chi square=0.75, p=0.39). When time to a confirmed cardiovascular endpoint alone was examined there was a suggestion of a benefit from Iloprost, but the difference was again not statistically significant (Logrank test, Chi square =0.82, p=0.37). There was no statistically significant change in the rate at which organ screening endpoints occurred throughout follow-up, and for each endpoint there was no statistically significant difference between results in patients randomised to Iloprost compared to those randomised to placebo. Withdrawal from the treatment to which the patient was randomised was frequent with 97 (45%) of the total participants discontinuing study medication. ‘On treatment’ analysis, undertaken using the endpoint of death or confirmed cardiovascular endpoint, just failed to show statistical significance at the 5% level (p=0.054). Conclusion: The results of the SSTEP study showed that there was a trend towards favouring oral Iloprost over placebo in systemic sclerosis, though there was no statistically significant evidence to recommend its use to prevent disease progression. The high rate of withdrawal from both Iloprost and placebo hindered the possibility of demonstrating that Iloprost was effective in this study. It cannot be concluded that it is a useful therapy that may prevent premature mortality or progression to cardiovascular disease in this patient group.

Much of this thesis describes the use of immunohistochemical methods on salivary glands from patients with Sjogren's syndrome (SS) to quantify the position, nature and proliferative activity of the inflammatory cell infiltrate, deposition of cell matrix proteins and glandular expression of TGFp. Studies are also undertaken on glands from an experimental animal model and from patients with two associated conditions, benign lymphoepithelial lesion (BLEL) and systemic sclerosis (SSc). Initially a rat model of SS was examined and changes in salivary glands quantified at different stages after autoimmunisation. Immunohistochemically there were similarities to SS, in that class II antigen was expressed by glandular epithelium and the early lesions contained T lymphocytes. However, B lymphocytes were rare, the cell infiltrate contained large populations of macrophages and neutrophils, and there was evidence of increased elaboration of fibrous connective tissue. These results indicate that this animal model is of doubtful use for the study of Sjogren's syndrome. Studies on human tissue showed that the lymphocyte infiltrate in BLEL patients was more extensive than SS and that T cells predominated in small foci, whereas B cells were the dominant lymphocyte type in larger foci. In areas of extensive lymphocyte infiltration, B cells were closely associated with ducts or present in germinal centre-like structures with T cells being found elsewhere. A previously unreported feature of BLEL was the presence of intra-epithelial (and intra-lumenal) B cells, many of which were proliferating. The remaining duct walls in BLEL appeared to be under pressure due to this population of B lymphocytes and "holes" were observed both in the basement membrane and at the lumenal surface that may facilitate migration of lymphocytes from glandular stroma into duct lumens. There was significantly more tenascin and fibronectin in BLEL glands (p<0.01) compared to normal parotid controls which contained minimal amounts of these proteins. By contrast, both proteins were expressed in normal labial glands with no significant increase in glands from SS and SSc patients. As both tenascin and fibronectin are important in cell migration, increased levels may be a factor facilitating lymphoid infiltration in BLEL. Absorbance measurements demonstrated that ductal expression of TGFI differed between control, SS and BLEL salivary glands. SS glands showed an increase in expression of all isoforms of TGFß with the increase for TGFP2 and TGFP3 being significant (p=0.02 & p<0.002). By contrast, ductal expression of all isoforms of TGFI in BLEL was reduced in both confluent (p<0.0001) and minimally infiltrated (p<0.005) areas of gland. Thus reduced glandular expression of TGFJ may be important in allowing the high levels of lymphocyte and epithelial cell proliferation detected in BLEL which are rarely seen in SS. Salivary glands from SSc and Raynaud's phenomenon (RP) patients contained small, predominately T cell foci with few proliferating B cells and a significantly increased mast cell population (p<0.005). Fibrosis within the glands was variable and not associated with increased deposition of fibronectin or tenascin. Subjectively, the most obvious difference in TGFI expression in SSc compared to controls was exhibited by fibroblasts. Cell counts revealed no differences in fibroblast expression of TGFßI or TGFß receptors. However, the percentage of TGFß2-positive fibroblasts was significantly higher in SSc glands compared to controls (p<0.004). RP glands showed an intermediate level of expression. By contrast, a lower percentage of RP fibroblasts expressed TGF(33 compared to controls, with SSc glands showing an intermediate level of expression. The results indicate that both SSc and RP are associated with an increased salivary gland mast cell population and changes in expression of TGFß2 and ß3 isoforms by glandular fibroblasts. The final section of this thesis describes an investigation of antioxidant levels in saliva from healthy individuals and patients with SS or periodontal disease. The results demonstrated that in SS there was an increase in the concentration of antioxidants in unstimulated saliva but a reduced rate of production. This diminished output of salivary gland antioxidants may be of significance to the oral health of these patients. In periodontal disease there was a reduction in antioxidant levels in stimulated saliva that may have been the result of local depletion by reactive oxygen species, produced by chronic inflammation within the gingival tissues. Alternatively, these patients may have intrinsically reduced levels of antioxidants and therefore be more susceptible to periodontal disease.

Scleroderma is a chronic autoimmune connective tissue disease of unknown etiology characterized by excessive fibrosis and is broadly divided into two clinical entities: localized scleroderma (LSc) and systemic sclerosis (SSc). SSc is a multi-system disease resulting in both skin and visceral organ fibrosis. The more benign disorder, LSc is for the most part self-limited with the disease pathology being confined to the skin and subcutaneous tissues. Proposed factors involved in the pathogenesis of these disorders include endothelial cell injury and dysfunction, immunological alterations and inflammatory activation, and abnormal ECM production by activated fibroblasts. However, the initiating mechanisms that leads to these changes remains largely unknown. This thesis examines the hypothesis that the transcriptional expression at the edge and centre of expanding LSc plaques could represent the metabolic changes involved in the different stages of disease. The major finding of this thesis was the identification of two panels of genes that showed significant changes in expression between LSc patients and healthy controls irrespective of whether the sample was taken from a diseased or clinically unaffected area of the patient. The first panel consisted of inflammatory genes including those genes characteristic of the Thl response and those induced by NF-KB. The Thl response was supported by an increased infiltration of CD4+ T cells in the LSc patients. The second panel consisted of a subset of array identified genes (scleroderma Signature) in SSc patients. Of interest, WIF1 was down regulated in both disorders and showed a gradual decrease in expression across the clinically different areas of the LSc patients. Both panels of genes showed the biggest changes of expression at the edge of the plaque suggesting their involvement in the initiating events of the disease. These results suggest that, like SSc, the underlying pathology of LSc is related to systemic changes in genes controlling amongst others, immunological and inflammatory responses. This information not only sheds light on the mechanisms involved in the initiation and progression of scleroderma, but could also contribute to the creation of a diagnostic test for the early detection of sufferers of this rare, but important disease.

Plusieurs rapports ont suggéré que les formes réactives de l'oxygène (FRO) et d'azote sont impliquées dans la pathogénèse de la ScS. Les fibroblastes ScS de la peau et des organes internes surproduisent des FRO qui déclenchent la prolifération des fibroblastes et la synthèse de collagène de type I, conduisant à l'initiation et à la progression de la ScS. Le laboratoire a mis au point un modèle de souris ScS, induite par injections itératives de HOCl. Comme dans la ScS humaine, les fibroblastes de la peau de souris ScS produisent de manière constitutive de grandes quantités de FRO. Nous avons utilisé cette propriété pour induire sélectivement l'apoptose de fibroblastes de souris ScS. Le catalyseur organotelluride-(PHTE) 2NQ et le composé naturel Dipropyltertrasulfide (DPTTS) sont capables d'augmenter specifiquement la production de FRO par les fibroblastes et d’induire un stress oxydatif létal dans les fibroblastes sclérodermiques. Ce phénomène n'a aucun impact sur les fibroblastes normaux qui présentent des taux de FRO basaux faible et un statut oxydant / antioxydant normal. De nombreuses études ont également prouvé l’importance des espèces azotées dans la l’induction de la ScS. Chez les patients atteints de SSc, le taux sérique de l'oxyde nitrique est considérablement accru. De plus, le NO peut se combiner avec d'autres radicaux libres comme l'anion superoxyde (O•-2) pour former le peroxynitrite (ONOO-) qui est hautement cytotoxique et contribue à l'inflammation, la fibrose et l'apoptose des cellules endothéliales. La production de NO par les cellules endothéliales ou les fibroblastes peut être stimulée par l'angiotensine II, principal peptide de la voie rénine-angiotensine (RAS). Comme chez les patients atteints de sclérodermie, les souris HOCl/ScS présentent des taux sériques d'angiotensine II élevés, ce qui est favorable à la prolifération des fibroblastes, à la fibrose, et à l'inflammation. Ces observations nous ont conduites à tester les effets de l'Irbésartan, un antagoniste des récepteurs de l’angiotensine II de type I (AT1 RA) dans le ScS modèle murin. Un nouveau modèle animal basé sur l'exposition chronique à des ROS et présentant de nombreuses similitudes avec la maladie humaine, m'a permis d'étudier de nouveaux traitements de la ScS. Ces nouvelles approches sont basées sur l'action cytotoxique de composés pro-oxydants - (PHTE) 2NQ et DPTTS - et sur les effets anti-nitrosatifs de molécules comme l'Irbésartan. Ces stratégies thérapeutiques originales ouvrent des perspectives intéressantes dans le traitement de la ScS, où l'arsenal thérapeutique est actuellement encore limité. / Several reports have suggested that reactive oxygen and nitrogen species are involved in SSc pathogenesis. SSc fibroblast from skin and internal organs overproduce ROS that trigger the proliferation of fibroblasts and the synthesis of type I collagen leading to the initiation and progresion of SSc. As in human SSc, skin fibroblasts from SSc mice constitutively produce large amounts of ROS. We have used this property to selectively induce apoptosis in the diseased fibroblast of SSc mice. Indeed, the organotelluride catalyst-(PHTE)2NQ and natural organosulfur compound – Dipropyltertrasulfide (DPTTS) are able of increasing ROS production by fibroblasts and inducing a lethal oxidative stress specificaly in SSc fibroblasts. This phenomenon has no impact on normal fibroblasts that present normal levels of ROS and a normal oxidant/antioxidant status. Many studies have also proved an importance of nitrogen species in the pathogenesis of SSc. In patients with SSc, the serum level of nitric oxide is significantly increased. Furthermore, NO can combine with other free radicals like superoxide anion (O•-2) to form the highly cytotoxic peroxynitrite (ONOO−) that contributes to inflammation, fibrosis and apoptosis of endothelial cells. Production of NO by endothelial cells or by fibroblasts can be stimulated by angiotensin II, the main peptide of the renin-angiotensin system (RAS). The level of angiotensin II is increased in SSc patients as well as in our HOCl mouse model and can promote proliferation of fibroblasts, fibrosis, and inflammation. These observations led us to test irbesartan, an angiotensin II type I receptor antagonist (AT1 RA) in the murine model of SSc. A new animal model based on chronic exposure to ROS and with many similarities to the human disease, allowed me to study new therapeutic approaches in SSc based on the cytotoxic action of pro-oxidative compounds - (PHTE)2NQ and DPTTS - and on the anti- nitrosative effect of irbesartan. These new therapeutic strategies open interesting perspectives in the treatment of SSc, where the therapeutic arsenal is currently still limited.

Rapidly progressive diffuse systemic sclerosis (dSSc) is a life-threatening condition characterized by increased mortality with few effective therapies, typically only helpful in stabilizing disease. Autologous hematopoietic stem cell transplantation (AHSCT) is the only treatment that has demonstrated improved survival. Despite promising results from three randomized controlled trials (RCTs), best practice use of AHSCT in the real-world setting is not well established. The primary objective of this thesis was to summarize the clinical efficacy, limitations and utilization of AHSCT in the management of rapidly progressive dSSc. Specifically, we conducted (1) a systematic review to describe the efficacy of AHSCT in dSSc as well as practice variation in patient selection and treatment regimens; and (2) a multicenter retrospective cohort study to compare outcomes for subjects who received AHSCT in France compared to those who received conventional care in Canada. There was important variability in the criteria for patient selection and treatment protocols. While AHSCT is associated with improved overall survival, skin fibrosis and lung function, further studies are needed to understand its potential for expanded eligibility and effects on other disease manifestations.

Systemic sclerosis (SSc) is a chronic autoimmune disease of the connective tissue. Immune system dysregulation, excessive deposition of collagen and microvascular damage in the skin and multiple internal organs are the main pathologic characteristics of the disease. Little is known about the mechanisms that are responsible for the pathogenesis of SSc. However, evidence has been accumulated demonstrating that T cells play a key role in the initiation and propagation of the disease. Previous studies in our laboratory have identified the presence of high proportions of identical &beta;&ndash;chains TCR transcripts, demonstrating the presence of clonal expansion of T cells in skin biopsies from patients with SSc of recent onset. These T cells have undergone proliferation and clonal expansion in response to as yet unidentified antigen(s). The hypothesis that has been tested in this study is whether clonally expanded T cells in skin biopsies of patients with SSc of recent onset recognize self or non&ndash;self (possibly viral) putative SSc antigens, including DNA topoisomerase I, cytomegalovirus (CMV) and parvovirus. With the objective to identify the antigens recognized by clonally expanded T cells in skin biopsies of patients with SSc, we examined the presence of &alpha;&ndash; and &beta;&ndash;chain TCR transcripts. Amplification of &alpha;&ndash;chain TCR transcripts by the non&ndash;palindromic adaptor PCR (NPA&ndash;PCR)/V&alpha; specific PCR followed by cloning and sequencing revealed the presence of several clonally expanded &alpha;&ndash;chain TCR transcripts in skin biopsies from four patients with SSc and peripheral blood from one of these patients. Additionally, several clonally expanded &beta;&ndash;chain TCR transcripts were identified in skin biopsies from all three of these patients with SSc examined, after NPA&ndash;PCR/V&beta; specific amplification followed by cloning and sequencing. To identify the antigens recognized by these in vivo clonally expanded &alpha;&ndash; and &beta;&ndash;chain TCR clones, full length &alpha;&ndash; and &beta;&ndash; chain TCR transcripts containing the identified CDR3 regions from the clonally expanded TCR clones from the patients SSc&ndash;21 and SSc&ndash;22 were constructed. Pairs of clonally expanded, full length &alpha;&ndash; and &beta;&ndash;chain TCR transcripts and appropriate controls were expressed in mutant TCR negative cells of the Jurkat T cell line (J.RT3&ndash;T3.5) by using a retroviral gene transfer and expression system. Each clonally expanded &alpha;&ndash;chain TCR transcript was combined with each clonally expanded &beta;&ndash;chain TCR transcript from the same patient, generating T cells lines containing all pairing combinations of the clonally expanded TCR transcripts for each SSc patient. A total of 52 T cell lines were generated, including 10 control T cell lines. The surface expression of the TCR complex on these T cell lines was verified by flow cytometric analysis using antibodies against the &alpha;/&beta; TCR and CD3epsilon. We employed an intracellular calcium mobilization assay to examine whether the Jurkat T cell lines transduced with the clonally expanded TCR transcripts from skin biopsies from patients with SSc (SSc&ndash;21 and SSc&ndash;22) recognize putative SSc antigens or their peptides presented by autologous EBV&ndash;transformed B cell lines. The putative SSc antigens that were tested are the self&ndash;antigen, DNA topoisomerase I and the viral antigens, cytomegalovirus and parvovirus which have been previously suggested to be involved in the pathogenesis of SSc. Significant intracellular calcium mobilization was observed in response to 3 DNA topoisomerase I and 2 CMV peptides by 5 T cell lines transduced with clonally expanded &alpha;&ndash; and &beta;&ndash;chain TCR transcripts from patients SSc&ndash;21 and SSc&ndash;22. / Microbiology and Immunology