Apolipoprotein E controls Dectin-1-dependent development of monocyte-derived alveolar macrophages upon pulmonary β-glucan-induced inflammatory adaptation

The lung is constantly exposed to the outside world and optimal adaptation of immune responses is crucial for efficient pathogen clearance. However, mechanisms that lead to lung-associated macrophages' functional and developmental adaptation remain elusive. To reveal such mechanisms, we developed a reductionist model of environmental intranasal β-glucan exposure, allowing for the detailed interrogation of molecular mechanisms of pulmonary macrophage adaptation. Employing single-cell transcriptomics, high-dimensional imaging and flow cytometric characterization paired with in vivo and ex vivo challenge models, we reveal that pulmonary low-grade inflammation results in the development of apolipoprotein E (ApoE)-dependent monocyte-derived alveolar macrophages (ApoE+CD11b+ AMs). ApoE+CD11b+ AMs expressed high levels of CD11b, ApoE, Gpnmb and Ccl6, were glycolytic, highly phagocytic and produced large amounts of interleukin-6 upon restimulation. Functional differences were cell intrinsic, and myeloid cell-specific ApoE ablation inhibited Ly6c+ monocyte to ApoE+CD11b+ AM differentiation dependent on macrophage colony-stimulating factor secretion, promoting ApoE+CD11b+ AM cell death and thus impeding ApoE+CD11b+ AM maintenance. In vivo, β-glucan-elicited ApoE+CD11b+ AMs limited the bacterial burden of Legionella pneumophilia after infection and improved the disease outcome in vivo and ex vivo in a murine lung fibrosis model. Collectively these data identify ApoE+CD11b+ AMs generated upon environmental cues, under the control of ApoE signaling, as an essential determinant for lung adaptation enhancing tissue resilience.

Healthcare utilization and unmet needs of patients with antisynthetase syndrome: An international patient survey

Antisynthease syndrome (ASSD) is a rare, complex and understudied autoimmune disease. Internet-based studies can overcome barriers of traditional on-site research and are therefore very appealing for rare diseases. The aim of this study was to investigate patient-reported symptoms, diagnostic delay, symptoms, medical care, health status, working status, disease knowledge and willingness to participate in research of ASSD patients by conducting an international web-based survey. The multilingual questionnaire was created by an international group of rheumatologists and patients and distributed online. 236 participants from 22 countries completed the survey. 184/236 (78.0%) were female, mean age (SD) was 49.6 years (11.3) and most common antisynthetase antibody was Jo-1 (169/236, 71.6%). 79/236 (33.5%) reported to work full-time. Median diagnostic delay was one year. The most common symptom at disease onset was fatigue 159/236 (67.4%), followed by myalgia 130/236 (55.1%). The complete triad of myositis, arthritis and lung involvement verified by a clinician was present in 42/236 (17.8%) at disease onset and in 88/236 (37.3%) during the disease course. 36/236 (15.3%) reported to have been diagnosed with fibromyalgia and 40/236 (16.3%) with depression. The most reported immunosuppressive treatments were oral corticosteroids 179/236 (75.9%), followed by rituximab 85/236 (36.0%). 73/236 (30.9%) had received physiotherapy treatment. 71/236 (30.1%) reported to know useful online information sources related to ASSD. 223/236 (94.5%) were willing to share health data for research purposes once a year. Our results reiterate that internet-based research is invaluable for cooperating with patients to foster knowledge in rare diseases.

POS0385 “EFFECTIVE LUNG AGE” IN SUBJECTS WITH SYSTEMIC SCLEROSIS-ASSOCIATED INTERSTITIAL LUNG DISEASE (SSc-ILD) IN THE SENSCIS TRIAL

Background

FVC declines gradually with aging. The loss of lung function in patients with progressive SSc-ILD mimics an accelerated ageing process.

Objectives

Using reference equations, we estimated the “effective lung age” of subjects in the SENSCIS trial (i.e. the age of healthy individuals with the same FVC) and compared these estimates to their real age.

Methods

The SENSCIS trial enrolled subjects with SSc-ILD with first non-Raynaud symptom within the prior ≤7 years, extent of fibrotic ILD on HRCT ≥10%, FVC ≥40% predicted, DLco 30–89% predicted. Evidence of recent decline in FVC was not an inclusion criterion. Subjects were randomised to receive nintedanib or placebo. Using reference equations published by the European Respiratory Society Global Lung Function Initiative, based on FVC data from over 70,000 healthy individuals aged 3–95 years from 26 countries, [Quanjer et al. Eur Respir J 2012;40:1324–1343], we estimated the effective lung age of subjects at baseline and at week 52 based on their FVC, sex, ethnicity and height, and compared these effective lung ages with the subjects’ real ages. Three subjects aged <25 years were excluded. The upper limit of effective lung age was considered to be 95 years.

Results

Mean time since onset of first non-Raynaud symptom was 3.5 years in both the nintedanib and placebo groups. At baseline, mean (SD) effective lung age was 83.1 (14.4) years in the nintedanib group (n=287) and 82.9 (14.8) years in the placebo group (n=286). In these groups, respectively, the mean (SD) difference between effective lung age and real age was 28.4 (17.7) and 29.3 (18.5) years and the difference was >20 years in 71.4% and 72.4% of subjects. In the nintedanib and placebo groups, respectively, median (Q1, Q3) effective lung age was 88.4 (74.6, 95.0) and 88.5 (74.7, 95.0) years at baseline and 91.0 (75.2, 95.0) and 95.0 (75.9, 95.0) years at week 52.

Conclusion

At entry into the SENSCIS trial, subjects with SSc-ILD had an effective lung age that was much higher than their real age. Over 52 weeks, the increase in effective lung age was numerically lower in subjects treated with nintedanib than placebo. These data show that marked loss of lung function that can occur in the few years following onset of SSc-ILD and support a benefit of nintedanib in slowing the progression of SSc-ILD.

Acknowledgements

The SENSCIS trial was funded by Boehringer Ingelheim. Toby M Maher and Oliver Distler were members of the SENSCIS trial Steering Committee.

Disclosure of Interests

Toby Maher Speakers bureau: Boehringer Ingelheim, Galapagos, Genentech, Consultant of: AstraZeneca, Bayer, Blade Therapeutics, Boehringer Ingelheim, Bristol-Myers Squibb, Galapagos, Galecto, GlaxoSmithKline R&D, IQVIA, Pliant, Respivant, Roche, Theravance and Veracyte, Grant/research support from: AstraZeneca, GlaxoSmithKline, Arnaud Bourdin Speakers bureau: Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Novartis, Regeneron, Sanofi, Paid instructor for: Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Novartis, Regeneron, Sanofi, Consultant of: Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Novartis, Regeneron, Sanofi, Grant/research support from: AstraZeneca and Boehringer Ingelheim, Elizabeth Volkmann Speakers bureau: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Grant/research support from: Boehringer Ingelheim, Corbus, Forbius, Horizon, Kadmon, Serena Vettori Consultant of: Boehringer Ingelheim, Jörg H.W. Distler Shareholder of: 4D Science, Speakers bureau: Boehringer Ingelheim, Inventiva, Janssen, and UCB, Consultant of: AbbVie, Active Biotech, Anamar, ARXX, AstraZeneca, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GlaxoSmithKline, Inventiva, Janssen, Novartis, Pfizer, and UCB, Grant/research support from: Anamar, ARXX, Bristol-Myers Squibb, Bayer Pharma, Boehringer Ingelheim, Cantargia, Celgene, CSL Behring, Galapagos, GlaxoSmithKline, Inventiva, Kiniksa, Sanofi-Aventis, RedX, UCB, Margarida Alves Employee of: Margarida Alves is an employee of Boehringer Ingelheim, Christian Stock Employee of: Christian Stock is an employee of Boehringer Ingelheim, Oliver Distler Speakers bureau: OD has/had relationships with the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years:

Speaker fee: Bayer, Boehringer Ingelheim, Janssen, Medscape

, Consultant of: OD has/had relationships with the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years:

Consultancy fee: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur

OD has/had relationships with the following companies in the area of potential treatments for arthritides in the last three calendar years:

Consultancy fee: Abbvie

, Grant/research support from: OD has/had relationships with the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years:

Research Grants: Boehringer Ingelheim, Kymera, Mitsubishi Tanabe

POS0477 ATTENUATION OF FIBROBLAST ACTIVATION AND FIBROSIS BY ADROPIN IN A HEDGEHOG-DEPENDENT MANNER

Background

Adropin is a secretory protein encoded by the energy homeostasis-associated (ENHO) gene. Emerging evidence indicate its role in metabolism and energy homeostasis, which is known to be deregulated in SSc. However, adropin/ENHO has not been linked to the pathogenesis of fibrosis, tissue remodeling or fibroblast activation so far.

Objectives

The aim of the current study was to investigate the role of adropin/ENHO in the pathogenesis of fibroblast activation and fibrosis in SSc.

Methods

Machine learning and bioinformatics models were used to identify candidate genes regulating fibroblast activation in SSc. The expression of adropin/ENHO in skin samples of SSc patients and healthy individuals was analyzed by quantitative PCR, immunofluorescence and western blot, and validated by in silico data mining. The effects of adropin were analyzed in cultured human fibroblasts, 3D skin equivalents, and complimentary murine models of SSc, including sclerodermatous GvHD (sclGvHD) and bleomycin-induced lung fibrosis mice. RNA sequencing (RNAseq) was performed to identify downstream regulatory pathways.

Results

Biostatistical screening of publically available datasets identified adropin/ENHO as a potential molecular mediator involved in fibroblast activation with pronounced downregulation in SSc skin. We first confirmed the impaired expression of adropin/ENHO in SSc patients and SSc models. TGFβ reduced adropin/ENHO expression in a JNK-dependent manner. Recombinant Adropin peptides in turn inhibited TGFβ-induced fibroblast activation and subsequent fibrosis. Treatment of biologically active peptides adropin34−76 inhibited TGFβ induced fibroblast activation and extracellular matrix (ECM) production in cultured primary dermal fibroblasts, as well as in 3D skin equivalents. Moreover, therapeutical administration of adropin34−76 in mice with preestablished fibrosis exerted potent antifibrotic effects in skin and lungs of two complimentary murine SSc models, sclGvHD and bleomycin-induced lung fibrosis mice. RNAseq demonstrated the antifibrotic effects of adropin were functionally linked to hedgehog signaling and GLI1 deactivation, which experimentally confirmed in vitro and in vivo. Knockdown of GPR19, a putative receptor of adropin, abrogated the therapeutic effect of adropin on αSMA- and GLI1-expression in fibroblasts, indicating adropin may regulate GLI1 signaling and fibroblast activation via GRP19.

Conclusion

We demonstrate a novel regulatory loop of adropin/ENHO in TGFβ signaling: TGFβ inhibits the expression of adropin/ENHO, while recombinant adropin peptides inhibited fibroblast activation by GPR19-dependent inhibition of hedgehog/GLI1 signaling. Our findings characterize adropin peptides as a potential approach to interfere with aberrant fibroblast activation and tissue fibrosis in SSc.

References

[1]Liang R, Šumová B, Cordazzo C, Mallano T, Zhang Y, Wohlfahrt T, Dees C, Ramming A, Krasowska D, Michalska-Jakubus M, Distler O, Schett G, Šenolt L, Distler JH. The transcription factor GLI2 as a downstream mediator of transforming growth factor-β-induced fibroblast activation in SSc. Ann Rheum Dis. 2017 Apr;76(4):756-764. doi: 10.1136/annrheumdis-2016-209698. Epub 2016 Oct 28. PMID: 27793816.

Disclosure of Interests

Minrui Liang: None declared, Jörg H.W. Distler Shareholder of: stock owner of 4D Science, Consultant of: consultancy relationships with Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Medac, Novartis, Pfizer, RuiYi and UCB, Grant/research support from: has received research funding from Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Cantargia, Celgene, CSL Behring, Galapagos, GSK, Inventiva, Kiniksa, Sanofi-Aventis, RedX, UCB.

AB0130 DEREGULATION OF TFAM EXPRESSION PROMOTES MITOCHONDRIAL DAMAGE AND FIBROBLAST ACTIVATION IN SYSTEMIC SCLEROSIS

Background

Transcription factor A, mitochondrial (TFAM) is a transcription factor with essential function in the mitochondrial homeostasis, such as mitochondria biogenesis and mtDNA replication. Deregulation of TFAM expression has been linked to mitochondrial dysfunction. However, its role in the pathogenesis of rheumatic diseases has not been studied so far.

Objectives

We aimed to study the role of TFAM in the pathological fibroblast activation in SSc.

Methods

The expression of TFAM in SSc skin fibroblast and skin biopsies was analyzed by immunofluorescence and Western blot. The role of TFAM in fibroblast activation was investigated by TFAM knockdown in cultured fibroblasts. The role of TFAM in skin and lung fibrosis was further studied in mice with fibroblast specific knockout of TFAM in three independent mouse models: Bleomycin-induced skin and lung fibrosis as well as TβRIact-induced skin fibrosis.

Results

Dermal fibroblasts from SSc patients express lower level of TFAM in the skin and also after prolonged culture in vitro. The downregulation of TFAM impairs mitochondria homeostasis with decreased mitochondrial number, accumulation of damaged mitochondria with release of mtDNA, accumulation of deletions in mtDNA, metabolic reshaping with impaired OXPHOS and release of the mitokine GDF15. Long time, but not acute exposure of normal fibroblasts to TGFβ mimicked the finding in SSc fibroblasts with downregulation of TFAM and mitochondrial homeostasis disruption and damage. Knockdown TFAM of normal fibroblasts promotes fibroblast activation with increased myofibroblast differentiation and collagen release in a SMAD3 dependent manner. RNA sequencing demonstrated upregulation of pro-fibrotic genes and pathways. Mice with fibroblast-specific knockout of TFAM demonstrate are more sensitive to fibrotic stimuli such as bleomycin injection and TβRIact-overexpression and even demonstrate responses to NaCl instillation.

Conclusion

Alterations in the key mitochondrial transcription factor TFAM in response to prolonged activation of TGFβ and associated mitochondrial damage induce transcriptional programs that promote fibroblast activation and tissue fibrosis.

Disclosure of Interests

Xiang Zhou: None declared, Thuong Trinh-Minh: None declared, Cuong Tran Manh: None declared, Andreas Giessl: None declared, Christina Bergmann: None declared, Andrea-Hermina Györfi: None declared, Georg Schett: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB.,, Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB.

POS0883 BIOPHYSICAL PROPERTIES OF MONOCYTES INDICATE DISEASE ACTIVITY, SEVERITY OF FIBROTIC OR MICROVASCULAR MANIFESTATIONS AND THE RISK FOR PROGRESSION IN SYSTEMIC SCLEROSIS

Background

Dysregulated immune responses are major pathogenic players in systemic sclerosis (SSc). The biophysical properties (such as cell deformation, Young’s modulus (a measure of cell stiffness) and area) of circulating immune cells reflect their states and functions, as well as their pathological activation (1-3). Thus, biophysical phenotyping can provide access to a novel, mostly unexplored layer of information that is currently not accessible with standard techniques of cellular and molecular biology. Real-time fluorescence and deformability cytometry (RT-FDC) is a novel technique that enables biophysical phenotyping of individual immune cells at a high throughput, which allows its use in a clinical setting (3-5).

Objectives

Here, we hypothesized that biophysical properties of circulating immune cells in SSc and rheumatoid arthritis (RA) might specifically reflect their distinct pathophysiological activation in the respective disease, and might indicate clinical outcomes such as disease activity or severity. We thus performed RT-FDC-based biophysical phenotyping of circulating immune cells in SSc, RA and healthy controls.

Methods

63 SSc patients, 59 RA patients fulfilling the respective ACR/EULAR classification criteria and 18 age- and sex-matched healthy controls were included in the study between 05.2019 and 09.2021. Peripheral blood mononuclear cells (PBMC) were isolated and immunolabelled. PBMC subpopulations were identified in RT-FDC by standard gating strategies based on their marker expression and their deformation, Young’s modulus and area were determined.

Results

We identified SSc-specific changes (changes in SSc, but not in RA compared to healthy controls) in the biophysical properties of NK, NKT-like cells and monocyte subpopulations in SSc. Monocytes subpopulations had a higher deformation and cross-sectional area and/or more compact intra-donor distributions of these parameters in patients with active disease and with extensive skin or lung fibrosis in comparison with patients with stable disease and limited skin or lung fibrosis, respectively. All monocytes subsets were stiffer in patients with progression of skin of lung fibrosis at the time of measurement in comparison with a previous visit. The deformation and area of intermediate monocytes could also identify patients at risk for future progression of lung fibrosis. Changes in biophysical properties of monocytes can indicate, beyond fibrotic burden, clinical manifestations of microvascular damage such as active digital ulcers and pulmonary arterial hypertension.

Conclusion

We demonstrated that changes in the biophysical properties of monocytes subsets are associated with multiple clinical outcomes in SSc such as disease activity, severity of fibrotic or microvascular manifestations and risk of progression and might thus directly reflect SSc-specific pathologic immune cell activation. Our results thus provide first evidence that RT-FDC-based biophysical phenotyping of circulating immune cells may be a useful tool for clinical evaluation of SSc patients.

References

[1]Bashant KR, Toepfner N, Day CJ, Mehta NN, Kaplan MJ, Summers C, et al. The mechanics of myeloid cells. Biol Cell. 2020;112(4):103-12.

[2]Toepfner N, Herold C, Otto O, Rosendahl P, Jacobi A, Krater M, et al. Detection of human disease conditions by single-cell morpho-rheological phenotyping of blood. Elife. 2018;7.

[3]Kubankova M, Hohberger B, Hoffmanns J, Furst J, Herrmann M, Guck J, et al. Physical phenotype of blood cells is altered in COVID-19. Biophys J. 2021;120(14):2838-47.

[4]Otto O, Rosendahl P, Mietke A, Golfier S, Herold C, Klaue D, et al. Real-time deformability cytometry: on-the-fly cell mechanical phenotyping. Nat Methods. 2015;12(3):199-202, 4 p following

[5]Rosendahl P, Plak K, Jacobi A, Kraeter M, Toepfner N, Otto O, et al. Real-time fluorescence and deformability cytometry. Nat Methods. 2018;15(5):355-8.

Disclosure of Interests

Alexandru-Emil Matei: None declared, Kubánková Markéta: None declared, Liyan Xu: None declared, Andrea-Hermina Györfi: None declared, Evgenia Boxberger: None declared, Despina Soteriou: None declared, Maria Papava: None declared, Julia Prater: None declared, Xuezhi Hong: None declared, Martin Kräter: None declared, Georg Schett: None declared, Jochen Guck: None declared, Jörg H.W. Distler Shareholder of: JHWD is stock owner of 4D Science., Consultant of: JHWD has consultancy relationships with Actelion, Active Biotech, Anamar, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: JHWD has received research funding from Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

POS0873 PERSISTENT INFLAMMATION IN SYSTEMIC SCLEROSIS IS STRONGLY ASSOCIATED WITH SEVERE DISEASE AND MORTALITY: AN ANALYSIS FROM THE EUSTAR DATABASE

Background

Systemic sclerosis (SSc) is a heterogeneous autoimmune disease, with a high disease-related mortality and morbidity. A subset of patients show elevated CRP levels (20-35%), which has been reported as inflammatory SSc. Preliminary data suggest that this subset is characterized by a severe phenotype.

Objectives

To analyse the phenotype and the survival of inflammatory compared with non-inflammatory SSc patient subsets.

Methods

Data from 8571 SSc patients with available CRP measurement from the EUSTAR cohort were analysed. Exclusion criteria included acute infection, missing follow-up and tocilizumab treatment. Patients with a CRP ≥5mg/l at ≥80% of visits were stratified as persistent inflammatory and as non-inflammatory if CRP was ≥5 mg/l at <20% of visits (as described previously (1)). As a sensitivity analysis, patients were defined as inflammatory and non-inflammatory based on a single CRP measurement at baseline only (CRP ≥5 or <5mg/l, respectively). We compared baseline characteristics using Chi-square and non-parametric Kruskal–Wallis tests as appropriate. Kaplan Meier curves with log-rank tests were used to estimate time from baseline to death or censoring, and Cox regression to compare mortality risks adjusted for time from diagnosis to baseline.

Results

Out of 2883 patients with more than two visits, 404 (14%) showed persistent inflammation and 1032 (36%) a non-inflammatory phenotype. Out of 5619 patients with more than one visit, 1830 (33%) were stratified as inflammatory as defined by as single CRP measurement at baseline and 3789 (67%) as non-inflammatory. With both definitions, the inflammatory subset revealed a more severe phenotype than non-inflammatory patients, including more frequent diffuse-cutaneous disease, anti-Scl-70 autoantibodies, pulmonary fibrosis, pulmonary hypertension, higher modified Rodnan skin score, and lower forced vital capacity and diffusing capacity for carbon monoxide. Patients with persistent inflammation had a strongly increased risk of all-cause mortality (HR 7.1 [95%CI 3.7 to 13.5], p<0.001) compared to non-inflammatory patients, whereas this association was weaker when based on a single CRP measurement (HR 2.6 [95%CI 2.1 to 3.2], p<0.001).

Conclusion

The severe phenotype and decreased survival of the inflammatory SSc subset, which was most prominent in patients with persistently elevated CRP levels, suggest a distinct disease subset. Therefore both, the need for more regular monitoring of inflammatory parameters and implications for immune-modulating treatment, needs to be carefully analysed.

References

[1]Mitev, A., et al., Inflammatory stays inflammatory: a subgroup of systemic sclerosis characterized by high morbidity and inflammatory resistance to cyclophosphamide. Arthritis Res Ther, 2019. 21(1): p. 262. PMID: 31791379

Figure 1.

Overall mortality from baseline onward a. by persistent inflammatory phenotype, b. by inflammatory phenotype at baseline

Disclosure of Interests

Adela-Cristina Sarbu: None declared, Sabina Guler: None declared, Odile Stadler: None declared, Yannick Allanore: None declared, Vera Bernardino: None declared, Jörg H.W. Distler: None declared, Armando Gabrielli: None declared, Anna-Maria Hoffmann-Vold: None declared, Marco Matucci-Cerinic: None declared, Ulf Müller-Ladner: None declared, Vera Ortiz-Santamaria: None declared, Simona Rednic: None declared, Valeria Riccieri: None declared, Vanessa Smith: None declared, Susanne Ullman: None declared, Ulrich Walker: None declared, Thomas Geiser: None declared, Oliver Distler: None declared, Britta Maurer Speakers bureau: Boehringer-Ingelheim, Consultant of: Novartis, Boehringer Ingelheim, Janssen-Cilag, Grant/research support from: AbbVie, Protagen, Novartis Biomedical Research, Florian Kollert Shareholder of: Roche, Consultant of: BMS, Actelion, Boehringer-Ingelheim, Pfizer, Grant/research support from: Roche, Gilead, Pfizer, Employee of: Roche

POS0344 O-GlcNAcylation ON NUP153 REGULATES THE EARLY STAGES OF OSTEOCLASTOGENESIS THROUGH MYC NUCLEAR TRANSLOCATION

Background

Bone homeostasis is maintained by the balance between bone formation and resorption. In inflammatory arthritis, such as rheumatoid arthritis (RA), the pro-inflammatory environment promotes osteoclast differentiation and skews this balance towards bone resorption, leading to destructive bone erosion and bone loss. O-GlcNAcylation is one of the most common post-translational modifications, which attaches a single N-acetylglucosamine (GlcNAc) molecular to the serine or threonine of the target protein. O-GlcNAcylation is controlled by the activities of a single pair of enzymes: OGT, which facilitates the transfer of GlcNAc onto proteins; OGA, which removes GlcNAc from proteins. The activity of O-GlcNAcylation has been reported to be involved in several cellular events, such as transcription, translation, intracellular trafficking, and differentiation. We previously showed that the dynamics of O-GlcNAcylation are essential for osteoclast differentiation. TNF-α, a key pro-inflammatory factor in RA, intensified the O-GlcNAcylation dynamics. Inhibition of OGT arrests osteoclast precursors at early stages, whereas OGA inhibition blocks osteoclast maturation. However, the molecular mechanism of these regulations remains unclear.

Objectives

We aimed to identify the O-GlcNAcylation targets in osteoclast precursors in a pro-inflammatory milieu and to decipher the molecular mechanism of O-GlcNAcylation mediated regulation of osteoclastogenesis.

Methods

We first identify the O-GlcNAc-dependent molecular pathways in osteoclast precursors with pharmacological OGT and OGA inhibition by RNA sequencing. Then, we identified the O-GlcNAcylated proteins by mass spectrometry-based proteomics analysis and confirmed by immunoprecipitation. We found the potential molecular mechanism by combining the data from transcriptomics and proteomics. The proposed mechanism was further validated through siRNA-mediated knockdown and high-content screening analysis.

Results

Our transcriptomics data showed that OGT inhibition arrested osteoclast differentiation at early stages through interfering the cytokine signaling and metabolic adaption. The upstream analysis proposed MYC as the most potent regulator for the transcriptomic profile under OGT inhibition. Recent studies proposed MYC as a master regulator for metabolic reprograming during osteoclast differentiation. However, O-GlcNAcylation of MYC was not detected by mass spectrometry, suggesting indirect effects of O-GlcNAcylation on MYC signaling in osteoclast precursors. We detected upregulated levels of O-GlcNAc on NUP153, MTDH, RBM27, IFI207 upon RANKL+TNFα stimulation. An integrated analysis of transcriptomic and proteomic data by Ingenuity Pathway Analysis indicated that NUP153 might regulate the most DEGs among all the identified targets and indicated potential of NUP153 to regulate nuclear shuttling of MYC. Subcellular fractionation and confocal microscopy showed enhanced MYC nuclear translocation upon RANKL+TNFα stimulation, which could be blocked by NUP153 knockdown or OGT inhibition. Functionally, knockdown of NUP153 arrested cells at similar stages to OGT inhibition and reduced bone resorption ability. Together, these results suggest a model, in which O-GlcNAcylation regulates the shuttling activity of the nuclear pore component NUP153 to control the access of MYC to the nucleus during osteoclast differentiation.

Conclusion

Our results indicated that OGT inhibition arrests osteoclastogenesis at early stages through hampering MYC-dependent metabolic adaption. NUP153 was proposed as the most potent O-GlcNAcylation target by multi-omics data integration. NUP153-mediated MYC nuclear trafficking is required for osteoclast differentiation. These findings reveal the molecular mechanism of O-GlcNAcylation-dependent osteoclastogenesis and provide therapeutic insights on targeting O-GlcNAcylation in pathologic bone resorption.

Disclosure of Interests

Yi-Nan Li: None declared, Chih-Wei Chen: None declared, Thuong Trinh-Minh: None declared, ZHU Honglin: None declared, Philipp Hubel: None declared, Jens Pfannstiel: None declared, Georg Schett: None declared, Jörg H.W. Distler Shareholder of: 4D Science, Speakers bureau: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Employee of: FibroCure

POS0450 TEMPORAL MIGRATION OF IMMUNE CELLS FROM PSORIATIC SKIN TO JOINTS INITIATING SYNOVIAL INFLAMMATION IN PSORIATIC ARTHRITIS

Background

Spreading of inflammation from skin to joint is a key question behind the pathogenesis of psoriatic arthritis (PsA). Psoriasis (PsO), being one of the most prevalent skin diseases, usually anticipates joint manifestations, suggesting spreading of skin to joint disease, which happens in about 30% of the patients with psoriasis.1 To date, it is still obscure why the inflammatory process in some patients with PsO remains restrained to the skin, whereas in other patients it extents to tendons and joints.

Objectives

Using a pre-clinical model of PsA, we aimed to unveil the skin-joint axis, i.e. the spreading of psoriatic inflammation from the skin to the joints.

Methods

KAEDE transgenic mice expressing a photo-convertible fluorescent reporter were used to assess cell trafficking from inflamed skin to other organs in the mouse model of IL-23 overexpression (IL-23OE) induced PsA. Psoriatic skin lesions were irradiated with UV light to trigger the photoswitch from KAEDEGREEN to KAEDERED. Migration to different organs was determined by flow cytometry. Imaging flow cytometry was used to characterize the type of cells migrating from the skin to the joints. Migrating cells were further characterized by single-cell RNA-sequencing (scRNAseq) and functional analyses.

Results

MRI imaging and histological evaluation of IL-23OE mice revealed skin inflammation preceding joint inflammation in both wild-type and KAEDE-transgenic mice. Specific leukocyte migration from the skin to the joints started shortly after the onset of skin inflammation and before onset of inflammation within the joints of KAEDE transgenic mice. No migration was observed in healthy control animals. Other organs such as spleen or lymph nodes showed no model-dependent migration. Imaging flow cytometry revealed that the cells migrating to the joints were predominantly CD45+ CD11b+ cells. ScRNAseq analysis of sorted KAEDERED cells from inflamed joints confirmed that approximately 80% of the migrating cells were macrophages. Differential gene expression and pathway analysis revealed an imbalance between pro- and anti-inflammatory macrophages in the joints of experimental psoriatic arthritis.

Conclusion

We describe IL-23-mediated migration of skin-derived macrophages from the skin to the joints during the onset of experimental psoriatic arthritis. This process may explain the spreading from psoriatic skin to joint disease as these cells foster the development by local cytokine production once arrived in the joints.

References

[1]Veale, D.J. & Fearon, U. The pathogenesis of psoriatic arthritis. Lancet391, 2273-2284 (2018).

Disclosure of Interests

None declared.

POS0388 DEVELOPING A SCREENING TOOL FOR THE DETECTION OF INTERSTITIAL LUNG DISEASE IN SYSTEMIC SCLEROSIS: THE ILD-RISC RISK SCORE

Background

High resolution computed tomography (HRCT) is the gold standard for the diagnosis of systemic sclerosis associated interstitial lung disease (SSc-ILD). Although there is agreement in performing HRCT as a screening test at time of SSc diagnosis, some physicians do not regularly perform baseline HRCTs. In addition, it is unclear according to which criteria HRCTs should be repeated during the follow-up of baseline ILD negative patients.

Objectives

To develop a risk score for the presence of SSc-ILD (the ILD-RISC), to guide physicians in ordering both baseline and follow-up HRCTs.

Methods

The steering board included six SSc-ILD experts from referral centers, two fellows and a patient research partner. Items for regression analysis were selected according to face validity, feasibility, scientific background, and personal experience using the nominal group technique (NGT). The prediction model for the presence of ILD was developed from baseline visits of SSc patients from the six centers using multivariable logistic regression with backward selection. Patients were randomly divided into a derivation and validation cohort consisting of 66% and 34% of patients respectively. Patients with missing data in the selected covariates and in the ILD status (outcome) were excluded. After identifying a cut-off favoring sensitivity >85% from the ROC curve analysis, the derived ILD-RISC score was applied first in the validation cohort and then longitudinally in a cohort of SSc patients with negative baseline HRCT.

Results

The steering board selected 13 variables deemed important in the identification of SSc-ILD: sex, age, disease duration from first non-Raynaud’s phenomenon symptom, skin subset (diffuse/limited), presence of esophageal symptoms, digital ulcers (DU) ever, arthritis ever, smoking ever, increased inflammatory markers, NYHA functional class, SSc autoantibody status (SSc_Atb), FVC% and DLCO%. Among 780/3240 patients fulfilling the inclusion criteria, 533 (43% ILD) and 247 (48% ILD) respectively constituted the derivation and the validation cohort. In the derivation cohort, a model including FVC%, DLCO%, DU ever, age and SSc_Atb (Table 1A) showed an OR of 133.9 (95% CI 53.4-335.9) and an AUC of 79.1% (95% CI 75.3-83.0%) for the presence of ILD on HRCT (Figure 1). An ILD-RISC score ≥0.3 showed sensitivity of 85.6% and specificity of 53.6%, NPV of 83.2% and PPV of 58.2%, which were replicated in the validation cohort (Table 1B). Among 819 patients with negative baseline HRCT, 170 (20.8%) developed ILD during a 3.8±3.0 years follow up (1988 visits). Longitudinally, the ILD-RISC score showed comparable sensitivity and specificity (Table 1B).

Table 1.A)ILD-RISC MODEL VARIABLESOR95% CIp valueDigital ulcers, ever2.0581.347-3.145<0.001Age1.0261.010-1.0420.001SSc_ATBAnti-centromere0.3340.198-0.563<0.001Anti-topoisomerase I2.3791.326-4.2670.004Anti-RNA-polymerase III1.4070.636-3.1130.399Anti-Pm/Scl2.5560.916-7.1350.073None of the aboveComparatorFVC%0.9900.979-1.0020.091DLCO%0.9710.960-0.982<0.001B)ILD-RISC SCORE PERFORMANCEDerivation cohortValidation cohortLongitudinal cohortAll Patients/ILD patients533/229247/119819/170AUC %, 95% CI79.1 (75.3 – 83.0)76.4 (71.0 – 82.7)72.6 (68.9 – 76.2)Sensitivity %, 95% CI85.6 (80.4 – 89.9)85.7 (78.1 – 91.5)80.4 (73.9 – 86.0)Specificity %, 95% CI53.6 (47.8 – 59.3)49.2 (40.3 – 58.2)50.5 (48.2 – 52.9)Negative Predictive Value %, 95% CI83.2 (77.2 – 88.1)78.8 (68.2 – 87.1)96.3 (94.9 – 97.4)Positive Predictive Value %, 95% CI58.2 (52.7 – 63.5)61.1 (53.2 – 68.5)13.9 (11.8 – 16.1)

Conclusion

We developed and validated the ILD-RISC score to predict the presence of ILD at time of diagnosis and evaluated its performance during follow-up. The ILD-RISC may be useful in routine practice when resources for HRCTs might be limited. In particular, it may also help to decide when to order HRCTs at follow up, thus limiting unnecessary HRCTs and reducing the burden for patients and institutions.

Disclosure of Interests

Cosimo Bruni Speakers bureau: Actelion, Consultant of: Boehringer-Ingelheim, Eli-Lilly, Grant/research support from: New Horizon fellowship, FOREUM, EUSTAR, GILS, Lorenzo Tofani: None declared, Håvard Fretheim: None declared, Sophie Liem: None declared, Arthiha Velauthapillai: None declared, Hilde Jenssen Bjørkekjær: None declared, Imon Barua: None declared, Ilaria Galetti: None declared, Alexandru Garaiman: None declared, Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Consultant of: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Grant/research support from: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Anna-Maria Hoffmann-Vold Consultant of: Actelion, ARXX therapeutics, Bayer, Janssen, MSD, Lilly, Roche, Boehringer-Ingelheim, Medscape., Jeska de Vries-Bouwstra Speakers bureau: Payment for presentations and educational events by Boehringer Ingelheim and Janssen, Consultant of: Janssen and Boehringer Ingelheim, Abbvie, Grant/research support from: Roche, Galapagos and Janssen, ZonMW and ReumaNederland, Madelon Vonk: None declared, Jörg H.W. Distler Shareholder of: J.H.W.D. is stock owner of 4D Science and Scientific head of FibroCure., Grant/research support from: J.H.W.D. has received research funding from Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB., Marco Matucci-Cerinic Speakers bureau: Biogen, Bayer, Boehringer-Ingelheim, CSL Behring, Eli-Lilly., Consultant of: Actelion, Biogen, Bayer, Boehringer-Ingelheim, CSL Behring, Eli-Lilly., Grant/research support from: Actelion, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim

POS0893 FACTORS TO CONSIDER FOR MEASURING THE EFFECT OF LUNG FUNCTION ON PATIENT REPORTED OUTCOMES IN SYSTEMIC SCLEROSIS PATIENTS: ANALYSIS OF THE EUSTAR DATABASE

Background

Patient Reported Outcomes (PROs) are central to measure how patients feel and function especially when determining the effect of disease modifying agents. In patients with Systemic Sclerosis associated Interstitial Lung Disease (SSc-ILD), dyspnea is the main driver of HAQ decline but the effect of reduced lung function on both generic and specific measures of functional impairment is not well defined, and there are many potential confounding biases that could distort the apparent extent and direction of this relationship. Moreover, collider biases potentially induced by selection into the cohort and in clinical trials can also play a role.

Objectives

To define within the EUSTAR database, the correlation of Forced Vital Capacity (FVC) and functional impairment PROs and identify potential confounders to be considered in casual inference studies.

Methods

A cross-sectional analysis included for each patient with SSc-ILD (by X-ray and/or HRCT) in the EUSTAR registry the last visit with at least one PRO (Health Assessment Questionnaire Disability Index [HAQ-DI], Cochin hand function scale [CHFS] and/or dyspnoea visual analogue scale [VAS]) and % predicted FVC (%pFVC), if available. Patients with LVEF≤50% or pulmonary arterial hypertension at RHC were excluded. SSc-ILD with restricted lung volume was defined as %pFVC≤70 [1]. Spearman’s correlation analysis was performed. Results of this analysis and literature review were integrated to design a directed acyclic graph (DAG) and identify the appropriate confounder adjustment set for the total causal effect of FVC on functional impairment PROs.

Results

Among 17.338 SSc patients in the EUSTAR registry (extracted in November 2019), 727 SSc-ILD patients fulfilled the inclusion criteria (median %pFVC 90 (IQR 74-104), median %pDLCO 60 (IQR 47-52)). Patients with %pFVC<70 (n=149), as compared to those with %pFVC≥70 (n=578) had worse HAQ-DI, CHFS and VAS-dyspnoea scores (Table 1). In unadjusted analysis, %pFVC showed a weak correlation with HAQ-DI (r=-0.21) and CHFS (r=-0.17), but a stronger correlation with VAS dyspnoea (r=-0.33).

Table 1.

Results are reported as number/number available (%) for dichotomic variables, or as median (IQR) (n available) for continuous variables.

%pFVC≥70 (n=578)%pFVC<70 (n=149)Age at disease onset (years)60.6 (52.3-69.3) (546)52.5 (45.6-63-7) (137)Disease duration (months)134.4 (77.5-212.2) (546)110.3 (66.3-199.7) (137)Male sex84/578 (14.5)32/149 (21.5)Anti-Scl70+231/468 (40.7)81/122 (66.4)Smoker ever52/389 (13.4)17/107 (15.9)Caucasian ethnicity545/569 (95.8)131/145 (90.3)dcSSc167/559 (29.9)74/147 (50.3)Oesophageal symptoms319/571 (55.9)93/147 (63.3)Muscle weakness78/565 (13.8)37/149 (24.8)CRP elevation141/540 (26.1)53/134 (39.6)Elevated sPAP (ECHO)45/456 (9.9)21/121 (17.2)Pericardial effusion2/448 (0.4)4/110 (3.6)Diastolic function abnormality151/431 (35.0)31/102 (30.4)Conduction blocks78/480 (16.3)35/120 (29.2)%pDLCO62 (52-74) (527)42 (35-53) (118)CHFS7 (1-23) (493)16 (2-34.8) (114)HAQ-DI0.63 (0.13-1.13) (578)1.25 (0.38-2) (139)VAS dyspnoea (0-100)15 (10-45) (391)40 (20-70) (109)NYHA stage 3/447/561 (8.4)37/143 (25.9)

Subsequently, we created a DAG showing the proposed causal pathway considered relevant to the relationship between FVC and HAQ (Figure 1).

Conclusion

Lung function as measured by FVC appears to correlate with worse patient-reported function in our unadjusted analysis of the large multicentre EUSTAR dataset. However, to estimate the total causal effect we must consider a multitude of potentially confounding factors, which need to be integrated and analysed in a causal inference framework. The proposed DAG will inform the development of simulations of the potential impact of bias (confounding, collider and omitted variable) on effect estimates we could obtain from EUSTAR cohort.

References

[1]Goh NS, et al. Am J Respir Crit Care Med, 2008.

Disclosure of Interests

Maria Grazia Lazzaroni Grant/research support from: Research grant from Boehringer-Ingelheim, Michelle Wilson Grant/research support from: Research grant from Boehringer-Ingelheim, Elizabeth Hensor: None declared, Jörg H.W. Distler: None declared, Giovanna Cuomo: None declared, Elise Siegert: None declared, Ulf Müller-Ladner: None declared, Yannick Allanore: None declared, Maria Joao Salvador: None declared, Branimir Anic: None declared, Ulrich Walker: None declared, László Czirják: None declared, Camillo Ribi: None declared, Cristina-Mihaela Tanaseanu: None declared, Armando Gabrielli: None declared, Anna-Maria Hoffmann-Vold: None declared, Oliver Distler: None declared, Francesco Del Galdo: None declared

POS0476 THE NUCLEAR RECEPTOR TR4 ORCHESTRATES CYTOSKELETAL ORGANIZATION IN A Gα12/ROCK-DEPENDENT MANNER TO PROMOTE MYOFIBROBLAST DIFFERENTIATION AND TISSUE FIBROSIS IN SYSTEMIC SCLEROSIS

Background

Nuclear receptors (NR) are a family of transcription factors. Several members of the NR family are candidates for targeted intervention in inflammatory and fibrotic diseases (1-2). Testicular receptor 4 (TR4), also known as Nr2c2, has been shown to regulate fundamental cellular processes such as differentiation, proliferation and growth factor signaling (3-4). However, its role in fibrotic diseases has not been investigated so far.

Objectives

The aim of the present study was to characterize the role of TR4 in the pathogenesis of fibrotic tissue remodeling in SSc and to interrogate its underlying mechanism.

Methods

Expression of TR4 was quantified by RT-PCR, Western blot and immunofluorescence. The effects of TR4 knockdown on collagen production and myofibroblast differentiation were analyzed in cultured human fibroblasts and in three mouse models with fibroblast-specific knockout of TR4. RNA sequencing was performed in TGFβ-stimulated human dermal fibroblasts transfected with TR4 siRNA or non-targeting siRNA. The implication of TR4 in cytoskeleton regulation was analyzed by ROCK activity assays, stress fiber formation and quantification of the ratio of filamentous (F)-actin/ globular (G)-actin. The functional role of ROCK and Gα12 was analyzed using small molecule inhibitors and siRNA, respectively.

Results

TR4 expression was upregulated in fibroblasts in the skin of SSc patients and fibrotic mouse models. The expression of TR4 was upregulated in a TGFβ- and SMAD3-dependent manner. TR4 knockdown inhibited TGFβ-induced myofibroblast differentiation and collagen release, whereas overexpression of TR4 promoted fibroblast activation. Fibroblastspecific knockout of TR4 ameliorated experimental dermal fibrosis induced by bleomycin, adTBR and in sclGVHD with decreases in dermal thickening, myofibroblast counts and hydroxyproline content. The RNASeq of TR4 knockdown fibroblasts stimulated with TGFβ identified 651 differentially expressed genes as compared to control fibroblasts. Differentially expressed genes included central profibrotic genes such as ACTA2, COL3A1, CCL12. gProfiler enrichment analysis of the TR4-DEGs revealed enrichment of multiple GO, GSEA and Reactome terms related to ECM release, cytoskeleton organization and Rho GTPases activity. Indeed, knockdown of TR4 ameliorated the induction of ROCK activity by TGFβ stimulation and reduced the shift in the ratio from globular (G) actin to filamentous (F) actin. Knockdown of TR4 strongly reduced the expression of the G-protein alpha-12 (Gα12). ROCK inhibition by Y27632 or knockdown of Gα12 inhibited the induction of αSMA and stress fiber formation induced by overexpression of TR4.

Conclusion

TR4 is upregulated in SSc in a TGFβ-dependent manner to promote fibroblast activation. Inhibition of TR4 interferes with TGFβ-induced activation of ROCK, prevents cytoskeletal remodeling and fibroblast-to-myofibroblast transition and ameliorates experimental fibrosis. As nuclear receptors are common targets for therapeutic intervention, TR4 may offer potential for antifibrotic therapies.

References

[1]Avouac J, Palumbo-Zerr K, et al. The nuclear receptor constitutive androstane receptor/NR1I3 enhances the profibrotic effects of transforming growth factor beta and contributes to the development of experimental dermal fibrosis. Arthritis Rheumatol. 2014;66(11):3140-50.

[2]Palumbo-Zerr K, Zerr P, et al. Orphan nuclear receptor NR4A1 regulates transforming growth factor-beta signaling and fibrosis. Nat Med. 2015;21(2):150-8.

[3]Bookout AL, Jeong Y, Downes M, Yu RT, Evans RM, Mangelsdorf DJ. Anatomical profiling of nuclear receptor expression reveals a hierarchical transcriptional network. Cell. 2006;126(4):789-99.

[4]Simandi Z, Cuaranta-Monroy I, Nagy L. Nuclear receptors as regulators of stem cell and cancer stem cell metabolism. Seminars in cell & developmental biology. 2013;24(10-12):716-23.

Disclosure of Interests

Lichong Shen: None declared, Yun Zhang: None declared, ZHU Honglin: None declared, Jörg H.W. Distler Shareholder of: stock owner of 4D Science GmbH, Consultant of: JHWD has consultancy relationships and/or has received research funding from AbbVie, Actelion, BMS, Celgene, Bayer Pharma, Boehringer Ingelheim, JB Therapeutics, Sanofi-Aventis, Novartis, UCB, GSK, Array Biopharma and Active Biotech in the area of potential treatments of SSc.

POS0467 DERSIMELAGON, A NOVEL ORAL MELANOCORTIN 1 RECEPTOR AGONIST, DEMONSTRATES DISEASE-MODIFYING EFFECTS IN PRECLINICAL MODELS OF SYSTEMIC SCLEROSIS

Background

Activation of melanocortin 1 receptor (MC1R) is known to have broad anti-inflammatory and anti-fibrotic effects. The bleomycin (BLM)-induced skin fibrosis murine model is well-established for systemic sclerosis (SSc). α-melanocyte-stimulating hormone, an endogenous ligand of MC1R, inhibits skin fibrosis and MC1R knock-out enhances skin fibrosis in this model. These pieces of evidence suggest that MC1R agonism has potential in the treatment of SSc.

Objectives

Dersimelagon phosphate (MT-7117) is an investigational small molecule that is an orally administered, selective agonist for MC1R. The purpose of this study is to investigate the potential of MT-7117 as a therapeutic agent for SSc by evaluating its efficacy and mechanism of action in complementary preclinical models. The expression and distribution of MC1R in the skin of SSc patients was investigated.

Methods

The effects of MT-7117 on skin fibrosis and lung inflammation were evaluated in BLM-induced SSc murine models that were optimized for prophylactic and therapeutic evaluation. Microarray-based gene expression analysis and serum protein profiling were performed to investigate the mechanism of action of MT-7117 in the BLM-induced SSc models. The effect of MT-7117 on TGF-β-induced activation of human dermal fibroblasts was evaluated in vitro. Immunohistochemical analyses of MC1R expression in skin samples from SSc patients were performed.

Results

Prophylactic treatment with MT-7117 (≥0.3 mg/kg/day p.o.) significantly inhibited the increase in collagen content of the skin, the serum level of surfactant protein D, and the weight of the lungs from BLM-induced skin fibrosis and lung inflammation model. Therapeutic treatment with MT-7117 (≥3 mg/kg/day p.o.) significantly suppressed skin thickening and the numbers of myofibroblasts in pre-established BLM-induced skin fibrosis model. Gene array analysis using the BLM-induced SSc model demonstrated changes in numerous categories related to macrophages, monocytes, and neutrophils, followed by endothelial cell-related categories after treatment with MT-7117. In the analysis that focused on biological functions, categories of inflammatory response, activation of antigen-presenting cells, angiogenesis, atherosclerosis, vasculogenesis, and vaso-occlusion were suppressed by MT-7117. In the analysis that focused on molecular signaling pathways, triggering receptor expressed on myeloid cells-1, IL-6, and oncostatin M involved in inflammation, and peroxisome proliferator-activated receptor that is related to fibrosis were all affected by MT-7117. Serum protein profiling using BLM-induced SSc model revealed that multiple SSc-related biomarkers including P-selectin, osteoprotegerin, cystatin C, growth and differentiation factor-15 and S100A9 were suppressed by MT-7117. MT-7117 inhibited the activation of human dermal fibroblasts by suppressing TGF-β-induced ACTA2 (encoding α-smooth muscle actin) mRNA elevation in vitro. Immunohistochemical analyses showed that MC1R positivity was observed in 40 of 50 diffuse cutaneous SSc patients. MC1R was expressed by monocytes/macrophages, neutrophils, blood vessels (endothelial cells), fibroblasts, and epidermis (keratinocytes) in the skin of SSc patients.

Conclusion

MT-7117 demonstrates disease-modifying effects in preclinical models of SSc. Investigations of its mechanism of action and target expression analyses indicate that MT-7117 exerts its positive effects by affecting the pathologies of inflammation, vascular dysfunction, and fibrosis through inflammatory cells, endothelial cells, and fibroblasts. In view of its potent beneficial impact on all these three main pathologies of SSc, MT-7117 is a potential therapeutic agent for the treatment of clinically challenging SSc, which has diverse and difficult to treat symptoms. A phase 2 clinical trial investigating the efficacy and tolerability of MT-7117 in patients with early, progressive diffuse cutaneous SSc is currently in progress.

Disclosure of Interests

Masahiro Kondo Employee of: Mitsubishi Tanabe Pharma Corporation, Tsuyoshi Suzuki Employee of: Mitsubishi Tanabe Pharma Corporation, Yuko Kawano Employee of: Mitsubishi Tanabe Pharma Corporation, Shinji Kojima Employee of: Mitsubishi Tanabe Pharma Corporation, Masahiko Miyashiro Employee of: Mitsubishi Tanabe Pharma Corporation, Atsuhiro Matsumoto Employee of: Mitsubishi Tanabe Pharma Corporation, Gabriela Kania: None declared, Przemyslaw Blyszczuk: None declared, rebecca ross: None declared, Panji Mulipa: None declared, Francesco Del Galdo Grant/research support from: Prof. F. Del Galdo received fees and research support from Abbvie, AstraZeneca, Boehringer-Ingelheim, Capella, Chemomab, Kymab, Janssen and Mitsubishi-Tanabe., Yun Zhang: None declared, Jörg H.W. Distler Grant/research support from: Prof. J.H.W. Distler received consulting fees, lecture fees, and/or honoraria from Actelion, Active Biotech, Anamar, ARXX, aTyr, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, Sanofi-Aventis, RedX, RuiYi and UCB. J. H. W. Distler is stock owner of 4D Science and Scientific head of FibroCure.

POS0383 CLINICAL CHARACTERISTICS AND PROGNOSIS OF PATIENTS WITH SYSTEMIC SCLEROSIS SINE SCLERODERMA: DATA FROM THE INTERNATIONAL EUSTAR DATABASE

Background

LeRoy’s classification defines two main subsets of Systemic Sclerosis (SSc) based on the extent of skin fibrosis: limited cutaneous SSc (lcSSc) with skin thickening sparing the trunk and distal to the elbow and knees, and diffuse cutaneous SSc (dcSSc) with proximal and distal skin thickening. These two subsets notably differ in terms of survival and frequency of visceral involvement, dcSSc being less prevalent but having a higher mortality rate with more frequent visceral manifestations. SSc sine scleroderma (ssSSc) is a third subset initially described by Rodnan et al. and characterized by the absence of skin fibrosis but with the existence of SSc-associated visceral manifestations.

Objectives

This study aimed to characterise the main clinical features of patients with ssSSc in comparison with the lcSSc and dcSSc subsets within the international EUSTAR database.

Methods

All patients from the EUSTAR database fulfilling the ACR2013 or 1980 classification criteria for SSc assessed by the modified Rodnan Skin score (mRSS) at inclusion and with at least one follow-up visit were eligible. Sine scleroderma (ssSSc) was defined by the absence of skin thickening (mRSS=0 and no sclerodactyly) at all available visits. The clinical characteristics of these ssSSc patients were compared to those of patients with lcSSc and dcSSc with similar disease duration at last follow-up visit. Descriptive statistics were applied.

Results

Among the 4263 patients fulfilling the inclusion criteria, 376 (8.8%) were classified as ssSSc. Among them, 40.3% had puffy fingers, 39.4% had interstitial lung disease (ILD), 1.6% had a history of scleroderma renal crisis at inclusion visit. At last available visit, in comparison with 708 lcSSc and 708 dcSSc with the same disease duration, ssSSc patients had a lower prevalence of previous or current digital ulcers (28.2% versus 53.1% in lcSSc (P<0.001) and 68.3% in dcSSc (P<0.001)), of joint synovitis (16.9% versus 24.3% in lcSSc (P<0.01) and 30.8% in dcSSc (P<0.0001)), and of elevated sPAP on echocardiogram (15.2% versus 23.9% in lcSSc (P<0.01) and 28.7% in dcSSc (P<0.0001)). Despite similar disease duration, disease activity at follow up visit (assessed by the EScSG disease activity index 2001 and 2016) was lower in ssSSc in comparison with lcSSc and dcSSc. By contrast, the prevalence of ILD was almost similar in ssSSc and lcSSc (49.8% and 57.1% (P=0.03)) but significantly higher in dcSSc (75.0%, P<0.0001). Based on forced vital capacity, ILD was less severe in ssSSc in comparison with the other subsets (mean FVC 100% (SD=22)(%pred) versus 93% (SD=21) in lcSSc and 82% (SD=23) in dcSSc (P<0.0001 for both)). Anti-centromere antibodies were most represented in ssSSc (61.7% versus 41.9% in lcSSc (P<0.0001) and 16.3% in dcSSc (P<0.0001), whereas the opposite distribution was observed for anti-Scl70 antibodies. Survival was significantly higher in ssSSc patients compared to lcSSc (P<0.05) and dcSSc (P<0.0001).

Conclusion

This study highlights that ssSSc patients account for almost 10% of SSc patients with milder disease severity compared to both lcSSc and dcSSc.

Acknowledgements

The authors thank all EUSTAR collaborators

Disclosure of Interests

Alain LESCOAT: None declared, Suiyuan Huang: None declared, Patricia Carreira: None declared, Elise Siegert: None declared, Jeska de Vries-Bouwstra: None declared, Jörg H.W. Distler: None declared, Vanessa Smith: None declared, Francesco Del Galdo: None declared, Branimir Anic: None declared, Nemanja Damjanov: None declared, Simona Rednic: None declared, Camillo Ribi: None declared, DOMNIQUE FARGE: None declared, Anna-Maria Hoffmann-Vold Speakers bureau: Actelion, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Consultant of: Actelion, ARXX, Bayer, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Grant/research support from: Boehringer Ingelheim, Armando Gabrielli: None declared, Oliver Distler: None declared, Dinesh Khanna: None declared, Yannick Allanore: None declared

POS0864 ASSESSMENT OF SYSTEMIC SCLEROSIS RELATED MYOCARDIAL FIBROSIS BY 68Ga-FAPI-04 PET/CT

Background

Myocardial fibrosis is a poor prognostic factor and a relevant cause of SSc-related mortality. Current non-invasive screening methods for myocardial fibrosis (MF) include echocardiography, electrocardiography and serum Nt-pro-BNP, which are not specific for MF and not sensitive for early changes. Cardiac MRI predominately visualizes extracellular space changes as consequence of long-standing fibroblast activation. Direct visualization of the remodeling fibrotic remodeling process has not been feasible so far.

Objectives

Here, we use a tracer labeled probe directed against Fibroblast-Activation-Protein (FAP) to visualize activated fibroblasts in the myocardium of SSc patients and healthy individuals to test the hypothesis that FAPI-based PET imaging might enable the assessment of disease activity in SSc-related MF.

Methods

In this exploratory trial, 7 patients with SSc-related myocardial fibrosis (MF) confirmed by cardic MRI and 8 SSc patients without myocardial involvement were enrolled. All participants underwent 68Ga-FAPI-04 PET/CT imaging and cardiac MRI as well as echocardiography, electrocardiogram, and serum NT-pro-BNP. Patients were followed for at least 6 months including a follow-up cardiac MRI. Regional mapping of 68Ga-FAPI-04-uptake, late gadolinium enhancement (LGE) and T1-relaxation times were performed according to the American Heart Association 17 regions model. Myocardial tissue was analysed by immunofluorescence- (aSMA and FAP) and Sirius-Red staining.

Results

Myocardial FAPI-04-accumulation was significantly increased in SSc patients with myocardial fibrosis as defined by LGE in MRI compared to SSc patients without LGE. Consistent with the previously reported widespread remodeling in SSc-associated myocardial disease, the distribution of FAPI uptake was observed across multiple areas and did not correspond to the supply areas of the coronary arteries. Histological analyses of myocardial tissue biopsied from a LGE and 68Ga-FAPI-04-positive region revealed the accumulation of FAP+; SMA+ myofibroblasts in regions of pronounced collagen deposition. Slightly increased 68Ga-FAPI-04 -uptake values were observed in SSc patients without LGE, but with cardiovascular risk factors.

Comparing 68Ga-FAPI-04-uptake with cardiac MRI based mapping techniques, we observed a partial overlap for certain regions and differences in others. These observations suggest, that 68Ga-FAPI-PET/CT and cMRI could visualize different aspects of the disease process.

To confirm that 68Ga-FAPI-04-uptake assesses current molecular fibroblast activity rather than accumulating disease damage, we analyzed associations of 68Ga-FAPI-04-uptake with changes of clinical parameters of SSc-MF on follow-up: Here we observed different dynamics of change of 68Ga-FAPI-04-uptake and cardiac MRI-based, e.g. in response to start of immunosuppressive therapy.

Conclusion

Our study presents first in human evidence on a limited number of patients that FAPI-04-uptake correlates with fibrotic activity in SSc-associated myocardial fibrosis and that 68Ga-FAPI-04-PET/CT may thus improve risk stratification in this population.

Disclosure of Interests

None declared

POS0140 PREDICTING OUTCOMES IN SYSTEMIC SCLEROSIS: STRATIFICATION BY AUTO-ANTIBODIES OUTPERFORMS CUTANEOUS SUBSETTING IN THE EUSTAR COHORT

Background

Risk-stratification is key in a heterogeneous disease like systemic sclerosis (SSc). Until now, SSc patients are stratified according to the extent of skin involvement into limited cutaneous, diffuse cutaneous and sine scleroderma subtypes. However, this classification remains inaccurate to capture disease heterogeneity. Autoantibodies are found in more than 90% of the patients and can be detected before onset of the disease. Among them, three predominant and specific antibodies are used: anti-centromere, anti-Scl70 and RNA polymerase III antibodies.

Objectives

To compare the performances of stratification into LeRoy’s cutaneous subtypes versus autoantibody status in SSc versus combination of cutaneous subtypes and autoantibodies status.

Methods

Patients from the EUSTAR database were classified either as (i) limited cutaneous, diffuse cutaneous or sine scleroderma (based on the recording made by the treating physician) or (ii) according to autoantibodies with the following subclassifications: (1) no specific autoantibodies, (2) isolated ANA, (3) anti-centromere antibodies, (4) anti-Scl70 antibodies and (5) anti-RNA polymerase III antibodies or (iii) according to combination of cutaneous subset and auto-antibodies. The respective performance of each model to predict overall survival (OS), progression-free survival (PFS), disease progression and different organ involvements was assessed and the three models were compared by the area under the receiver operating characteristic curve (AUC 95%CI) and the net reclassification improvement (NRI). Missing data were imputed through multiple imputation using chain equations.

Results

In all, 10’711 patients were included: 84.6% females, mean age: 54.4±13.8 years, mean disease duration: 7.9±8.2 years. In the prospective analysis (n= 6’467 to 7’829 according to the outcome), after a mean follow-up of 56 months and a mean of three visits per patient, we did not identify any difference in AUC between the cutaneous-based model and the antibody-based model for prediction of OS and disease progression. However, the NRI showed a significant improvement in prediction of OS (0.57 [0.46-0.71] vs. 0.29 [0.19-0.39]) and disease progression (0.36 [0.29-0.46] vs. 0.21 [0.14-0.28]) at 4 years using the antibody-based model. Regarding prediction of each organ involvement in longitudinal analyses, the antibody-based model showed better performance than the cutaneous-one for renal crisis (AUC: 0.719 [0.696-0.742] vs. 0.664 [0.643-0.685]), with the highest association observed with anti-RNA polymerase III (OR: 7.47 [1.63-34.24], p= 0.010). Similarly, the antibody-based model was better than the cutaneous model in predicting lung fibrosis (AUC 0.719 [0.715-724] vs. 0.653 [0.647-0.659]) and restrictive lung fibrosis (AUC 0.759 [0.749-0.766] vs. 0.711 [0.701-0.721]) which were both associated with anti-Scl70 antibodies (OR: 9.29 [8.17-10.55] and 7.92 [5.37-11.69], respectively, p<0.0001 for both). Although there was no difference in the AUC to predict digital ulcers, NRI showed an improvement using the antibody-based model (0.31 [0.29-0.33] vs. 0.24 [0.22-0.26]) with the highest association with anti-Scl70 antibodies (OR: 3.57 [2.68-4.75], p<0.0001). The two models had similar performances in assessing occurrence of intestinal involvement, heart dysfunction or elevated sPAP. Combining both antibody status and cutaneous subtype did not improve the performance of our models. In the exploratory analysis, there was no change using modified Rodnan skin score to define cutaneous form.

Conclusion

Auto-antibody status outperforms the common cutaneous subsetting to risk-stratify SSc patients in the EUSTAR cohort. This easily performed subclassification using autoantibodies specific status can be used by the clinicians to risk-stratify their patients and to adapt disease monitoring in routine practice.

Disclosure of Interests

Muriel Elhai Speakers bureau: BMS outside of the submitted work, Marouane Boubaya: None declared, Nanthara Sritharan: None declared, Alexandra Balbir-Gurman: None declared, Elise Siegert: None declared, Eric Hachulla: None declared, Jeska de Vries-Bouwstra: None declared, Gabriela Riemekasten: None declared, Jörg H.W. Distler: None declared, Douglas Veale: None declared, Edoardo Rosato: None declared, Francesco Del Galdo: None declared, Fabian A Mendoza: None declared, Daniel Furst Consultant of: Abbvie, Novartis, Pfizer, R-Pharm, Grant/research support from: Emerald, Kadmon, PICORI, Pfizer,Prometheus, Talaris, Mitsubishi, Carlos De la Puente Bujidos: None declared, Anna-Maria Hoffmann-Vold Speakers bureau: Actelion, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Consultant of: Actelion, ARXX, Bayer, Boehringer Ingelheim, Jansen, Lilly, Medscape, Merck Sharp & Dohme, Roche, Grant/research support from: Boehringer Ingelheim, Armando Gabrielli: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Coralie Bloch-Queyrat: None declared, Yannick Allanore Consultant of: Actelion, Bayer, BMS, Boehringer-Ingelheim, Inventiva, Roche, Sanofi-Aventis, Grant/research support from: Actelion, Bayer, BMS, Boehringer-Ingelheim, Inventiva, Roche, Sanofi-Aventis

OP0201 DYNAMIC CHANGES IN O-GLCNACYLATION REGULATE OSTEOCLAST DIFFERENTIATION AND BONE LOSS IN ARTHRITIS

Background:

Bone remodeling is a constant process maintained by the balance between osteoclast-triggered bone resorption and osteoblast-mediated bone formation. In inflammatory arthritis, such as rheumatoid arthritis (RA), the pro-inflammatory environment favors osteoclast differentiation and skews the balance towards resorption, leading to progressive bone erosion and bone loss. O-GlcNAcylation is a post-translational modification, which transfers a single N-acetylglucosamine molecule to the serine or threonine of the target protein. The modification is accomplished by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Unlike other glycosylation, O-GlcNAcylation occurs in multiple cellular compartments, including the nucleus. Although O-GlcNAcylation is one of the most common modifications, its role in bone homeostasis is still poorly understood.

Objectives:

We aimed to investigate the role of O-GlcNAcylation in osteoclastogenesis under pro-inflammatory milieus. We also focused on dissecting the signaling pathways affected by O-GlcNAcylation during osteoclast differentiation.

Methods:

We examined the levels of O-GlcNAc during in vitro osteoclastogenesis by western blotting. The levels of O-GlcNAc in tissue from RA patients and experimental arthritis were detected by immunofluorescence. Pharmacological inhibition and genetic knockout were used to manipulate O-GlcNAcylaiton during osteoclastogenesis. RNA sequencing was performed to study O-GlcNAc-mediated pathways.

Results:

We demonstrate the dynamic changes in O-GlcNAcylation during osteoclastogenesis. The elevated O-GlcNAcylation was found in the early differentiation stages, whereas its downregulation was detected in the maturation process. TNFα elaborates the dynamic changes in O-GlcNAcylation, which further intensifies osteoclast differentiation.

Targeting OGT by selective inhibitor and genetic knockout restrain O-GlcNAcylation and hinder the expression of the early differentiation marker Nfatc1. Inhibition of OGA, which forces high levels of O-GlcNAcylation throughout the differentiation, reduces the formation of multinucleated mature osteoclasts. Consistent with our in vitro data, suppressing OGT and OGA both ameliorate bone loss in experimental arthritis. We detected a reduced number of TRAP-expressing precursors and mature osteoclasts in the mice subjected to OGT inhibition. While inhibiting OGA only lowers the number of TRAP+F4/80– mature osteoclasts without affecting the number of TRAP+F4/80+ precursors.

Transcriptome profiling reveals that O-GlcNAcylation regulates several biological processes. Increased O-GlcNAcylation promotes cytokine signaling and oxidative phosphorylation. The downregulation of O-GlcNAcylation is essential for cytoskeleton organization and cell fusion.

Conclusion:

We demonstrate that the dynamic changes of O-GlcNAcylation are essential for osteoclast differentiation. These findings reveal the therapeutic potential of targeting O-GlcNAcylation in pathologic bone resorption.

Disclosure of Interests:

Chih-Wei Chen: None declared, Yi-Nan Li: None declared, Thuong Trinh-Minh: None declared, ZHU Honglin: None declared, Alexandru-Emil Matei: None declared, Xiao Ding: None declared, Cuong Tran Manh: None declared, Xiaohan Xu: None declared, Christoph Liebel: None declared, Ruifang Liang: None declared, Min-Chuan Huang: None declared, Neng-Yu Lin: None declared, Andreas Ramming Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Grant/research support from: Pfizer, Novartis, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg H.W. Distler Shareholder of: 4D Science, Speakers bureau: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Employee of: FibroCure

POS0423 NCOA3 AMPLIFIES PROFIBROTIC TRANSCRIPTIONAL PROGRAMS IN SYSTEMIC SCLEROSIS

Background:

Excessive activation of fibroblasts with a TGFβ-biased gene signature and deposition of extracellular matrix are key features of fibrotic diseases. The mechanisms underlying these transcriptional changes remain poorly understood. Deregulation, mutations and malfunctions of transcriptional co-regulators, which can interact with multiple transcription factors and enable a broad-spectrum regulation of transcriptional networks, have been implicated as driving factors in a large number of diseases and pathologies.

Objectives:

In the present study, we aimed to analyze the role of the co-regulator Nuclear Receptor Co-Activator 3 (NCOA3) in fibroblast activation and tissue fibrosis, and to evaluate a potential interaction of NCOA3 with fibrosis-relevant transcription factors.

Methods:

NCOA3 was inhibited genetically by siRNA transfection and pharmacologically by the SRC3 inhibitor-2 (SI-2). We performed bulk RNASeq of human dermal fibroblasts and in silico transcription factor binding site screening of differentially expressed genes (DEGs). The interaction of NCOA3 and TGFβ-SMAD signaling was analyzed by reporter and CoIP assays.

Results:

The expression of NCOA3 in skin biopsies of SSc patients compared to normal controls demonstrated that SSc fibroblasts express modestly, but significantly reduced levels of NCOA3, which persisted in cultured SSc fibroblasts. Stimulation of normal fibroblasts with chronically high levels of TGFβ as they also occur in fibrotic tissue remodeling strongly decreased NCOA3 expression to a similar extent as in SSc fibroblasts. Furthermore, NCOA3 expression is also deregulated in different murine models of skin fibrosis. To investigate the functional effects of decreased NCOA3 levels, we targeted the expression of NCOA3 in normal fibroblasts. SiRNA-mediated knockdown of NCOA3 ameliorated TGFβ-induced gene expression, collagen release, myofibroblast differentiation and cell proliferation. In contrast, knockdown of NCOA3 had no effects on collagen release, expression of contractile proteins or gene expression in unstimulated fibroblasts, suggesting that NCOA3 is not required for cellular homeostasis. To characterize the molecular mechanisms, we performed RNASeq upon NCOA3 knockdown. We identified 343 significant differentially expressed genes (220 downregulated and 123 upregulated with a Benjamini-Hochberg false discovery rate FDR < 0.25 and fold change > 1.5) between TGFβ-stimulated fibroblasts with and without NCOA3 knockdown (NCOA3-DEGs) including the fibrosis-relevant genes EDNRB, COL5A3, HES1, IL11 or IL33. Functional analysis of the NCOA3-DEGs showed enrichment of pathway terms such as collagen binding and extracellular matrix organization. In silico screening of the promoters of the NCOA3-DEGs for potential transcription factor binding motifs revealed binding motifs of core transcription factors of fibroblast activation and tissue fibrosis such as SMAD2/3/4, RBPJ, ZEB1, TCF4, REL, and SNAIL2 amongst the downregulated NCOA3-DEGs. Experimental validation of our biostatistical results using SMAD3 as example demonstrated a higher percentage of NCOA3-pSMAD3 double-positive fibroblasts in skin sections of SSc patients compared to healthy controls. In addition, knockdown of NCOA3 reduced TGFβ-induced SMAD-reporter activity. Furthermore, stimulation with TGFβ increased the interaction of NCOA3 with SMAD3 as analyzed by co-immunoprecipitation. Simultaneous knockdown of NCOA3 and SMAD3 showed no additional reductions compared to the single knockdowns, suggesting that NCOA3 controls SMAD3-dependent gene transcription under fibrotic conditions. Finally, inhibition of NCOA3 showed anti-fibrotic effects in different murine models of experimental skin and lung fibrosis.

Conclusion:

Our findings characterize NCOA3 as regulator of multiple pro-fibrotic transcription programs. Pharmaceutical inhibition of NCOA3 might be a strategy to interfere simultaneously with several core pro-fibrotic mediators in fibrotic diseases such as SSc.

Acknowledgements:

We thank Lena Summa, Vladyslav Fedorchenko, Wolfgang Espach and Regina Kleinlein for excellent technical assistance.

The study was funded by grants DI 1537/7-1, DI 1537/8-1, DI 1537/9-1 and -2, DI 1537/11-1, DI 1537/12-1, DI 1537/13-1, DI 1537/14-1, DI 1537/17-1, DE 2414/2-1, DE 2414/4-1, and RA 2506/3-1 of the German Research Foundation, SFB CRC1181 (project C01) and SFB TR221/ project number 324392634 (B04) of the German Research Foundation, grants J39, J40 and A64 of the IZKF in Erlangen, grant 2013.056.1 of the Wilhelm-Sander-Foundation, grants 2014_A47, 2014_A248 and 2014_A184 of the Else-Kröner-Fresenius-Foundation, grant 14-12-17-1-Bergmann of the ELAN-Foundation Erlangen, BMBF (Era-Net grant 01KT1801), MASCARA program, TP 2 and a Career Support Award of Medicine of the Ernst Jung Foundation.

Disclosure of Interests:

Clara Dees: None declared, Sebastian Poetter: None declared, Maximilian Fuchs: None declared, Christina Bergmann: None declared, Alexandru-Emil Matei: None declared, Andrea-Hermina Györfi: None declared, Alina Soare: None declared, Andreas Ramming: None declared, Paolo Ceppi: None declared, Georg Schett: None declared, Meik Kunz: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

POS0328 ENGRAILED 1 COORDINATES CYTOSKELETAL ORGANIZATION TO PROMOTE MYOFIBROBLAST DIFFERENTIATION AND FIBROTIC TISSUE REMODELING

Background:

Engrailed 1 (EN1) is a homeodomain-containing transcription factor with essential roles in embryonic development. In most cell types, the expression of EN1 is restricted to embryonic development. However, under pathological conditions, EN1 can be re-expressed to promote phenotypical adaptation. En1 is transiently expressed in the developing dermis of murine embryos in a distinct fibroblast lineage and silenced before birth (1). Former EN1-expressing cells give rise to a subpopulation of fibroblasts that has a high capacity for extracellular matrix production in adult murine skin. The role of EN1 in systemic sclerosis (SSc) was previously not explored.

Objectives:

To study the role of EN1 in the pathological activation of fibroblasts in tissue fibrosis.

Methods:

Bulk RNA-Seq and EN1 or SP1 ChIP-Seq were performed from cultured human dermal fibroblasts. The expression of EN1 was inhibited by siRNA. Cytoskeletal drugs paclitaxel, vinblastin and ROCK inhibitor (Y27632) were used to modulate the cytoskeleton in EN1 knockdown or overexpressing dermal fibroblasts. The role of EN1 in fibroblast activation was evaluated by functional experiments with EN1 knockdown or overexpression in standard 2D culture systems as well as in 3D skin equivalent models. The role of EN1 in skin fibrosis was further studied in En1fl/fl X Col6Cre mice, with fibroblast-specific knockout of En1 in three complementary mouse models: overexpression of a constitutively active TGFß-receptor I (TBRICA), bleomycin-induced skin fibrosis and TSK1 mice.

Results:

Pathologically activated dermal fibroblasts from SSc patients express higher levels of EN1 compared with age and sex matched healthy individuals in the skin and in vitro. TGFβ induces EN1 expression in fibroblasts in a SMAD3-dependent manner both in cultured fibroblasts and in murine skin. Knockdown of EN1 prevents TGFβ-induced fibroblast activation, whereas overexpression of EN1 fosters the pro-fibrotic effects of TGFβ with increased expression of αSMA, stress fibers and collagen. RNA sequencing demonstrates that EN1 induces a pro-fibrotic gene expression profile functionally related to cytoskeleton organization and ROCK activation. In silico analyses of the promoters of En1 target genes coupled with siRNA-mediated knockdown demonstrated that EN1 regulates these pro-fibrotic target genes by modulating the activity of regulatory modules that contain transcription factors of the specificity protein (SP) family. Functional experiments with selective modulators of ROCK and of microtubule polymerization confirm the coordinating role of EN1 on ROCK activity and the re-organization of cytoskeleton during myofibroblast differentiation in both conventional culture systems and 3D skin equivalents. Consistently, mice with fibroblast-specific knockout of En1 demonstrate impaired fibroblast-to-myofibroblast transition, reduced dermal thickening and impaired collagen deposition in the TBRICA, bleomycin-induced and TSK1 models.

Conclusion:

We characterize the homeodomain transcription factor EN1 as a molecular amplifier of TGFβ signaling in myofibroblast differentiation that coordinates cytoskeletal organization in a SP-dependent manner. EN1 might thus be a novel candidate for molecular targeted therapies to interfere with myofibroblast differentiation in fibrotic diseases.

References:

[1]Rinkevich Y, Walmsley GG, Hu MS, Maan ZN, Newman AM, Drukker M, et al. Skin fibrosis. Identification and isolation of a dermal lineage with intrinsic fibrogenic potential. Science. 2015;348(6232):aaa2151.

Disclosure of Interests:

Andrea-Hermina Györfi: None declared, Alexandru-Emil Matei: None declared, Maximilian Fuchs: None declared, Aleix Rius Rigau: None declared, Xuezhi Hong: None declared, ZHU Honglin: None declared, Markus Luber: None declared, Christina Bergmann: None declared, Clara Dees: None declared, Ingo Ludolph: None declared, Raymund Horch: None declared, Oliver Distler Consultant of: Actellion, AbbVie, Acceleron Pharma, Anamar, Amgen, Blade Therapeutics, CSL Behring, ChemomAb, Ergonex, Glenmark Pharma, GSK, Inventiva, Italfarmaco, iQvia, Medac, Medscape, Lilly, Sanofi, Target BioScience, UCB, Bayer, Boehringer Ingelheim, Catenion, iQone, Menarini, Mepha, Novartis, Mitsubishi, MSD, Roche, Pfizer, Georg Schett: None declared, Meik Kunz: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB., Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

OP0272 68GA-FAPI-04 PET/CT STUDY EXTENSION FOR THE ASSESSMENT OF FIBROBLAST ACTIVATION AND RISK EVALUATION IN SYSTEMIC SCLEROSIS-RELATED INTERSTITIAL LUNG DISEASE

Background:

Interstitial lung disease (ILD) is the most common cause of death in systemic sclerosis (SSc). To date, the progression of SSc-ILD is judged by the accrual of lung damage on computed tomography (CT) and functional decline (forced vital capacity). However, this approach does not directly assess the activity of tissue remodeling. Moreover, prediction of the course of ILD in individual SSc patients remains challenging. Fibroblast Activation Protein (FAP) is a specific, ex vivo validated marker for activated fibroblasts.

Objectives:

The aims of this study were: 1. To assess differences in the uptake of 68GA-FAPI 04 in SSc-ILD patients compared to controls, to analyze 2. whether 68GA-FAPI 04 uptake at baseline correlates with other risk factors of disease progression and 3. Whether 68GA-FAPI 04 uptake is associated with the course of SSc-ILD.

Methods:

Between September 2018 and April 2020, 21 patients with SSc-ILD confirmed by HRCT and onset of SSc-ILD within ≤ 5 years or signs of progressive ILD and 21 controls without ILD were consecutively enrolled. All participants underwent 68Ga-FAPI-04 PET/CT imaging and standard-of-care procedures including HRCT and lung function testing (PFT) at baseline. Patients with SSc-ILD patients were followed-up for 6 months with HRCT and PFT. Follow-up 68Ga-FAPI-04 PET/CT scans were obtained in a subset of patients treated with nintedanib. We compared baseline 68Ga-FAPI-04 PET/CT uptake to standard diagnostic tools and currently used predictors of ILD progression. The association of 68Ga-FAPI-04 uptake with changes in FVC was analyzed using mixed-effects models.

Results:

68Ga-FAPI-04 accumulated in fibrotic areas of the lungs in SSc-ILD compared to controls with a median (q1-q3 interval) wlSUVmean of 0.8 (0.6 to 2.1) in the SSc-ILD group and 0.5 (0.4 to 0.5) in the control group (p<0.0001 with Mann-Whitney test) and a median whole lung maximal standardized uptake value (wlSUVmax) of 4.4 (3.05 to 5.2) in the SSc-ILD group compared to 0.7 (0.65 to 0.7) in the control group (p<0.0001). wlFAPI-MAV and wlTL-FAPI were not measurable in control subjects, as no 68Ga-FAPI-04 uptake above background level was observed. In the SSc-ILD group the median wlFAPI-MAV was 254cm3 (163.4 to 442.3) and the median wlTL-FAPI was 183.6 cm3 (98.04 to 960.7). 68Ga-FAPI-04 uptake was higher in patients with extensive disease, with previous ILD progression or high EUSTAR activity scores. Increased 68Ga-FAPI-04 uptake at baseline was associated with progression of ILD independently of extent of involvement on HRCT scan and the forced vital capacity at baseline. In consecutive 68Ga-FAPI-04-PET/CTs, changes in 68Ga-FAPI-04 uptake was concordant with the observed response to the fibroblast-targeting antifibrotic agent nintedanib.

Conclusion:

Our study presents first in human evidence that 68Ga-FAPI-04-fibroblast uptake correlates with fibrotic activity and disease progression in the lungs of SSc-ILD patients and that 68Ga-FAPI-04-PET/CT may be of potential to improve risk assessment of SSc-ILD.

Figure 1.

A and B:68Ga-FAPI-04 PET/CT scan from a patient with SSc-ILD with selective 68Ga-FAPI-04 uptake in fibrotic areas of the left- and right lower lung lobes (red arrows), but not in non-fibrotic areas such as the middle lobe (green arrow). B Corresponding CT component.

Acknowledgements:

We gratefully acknowledge Prof. Uwe Haberkorn (University Hospital Heidelberg and DKFZ, Heidelberg, Germany) and iTheranostics Inc. (Dulles, VA, USA) for providing the precursor FAPI-04.

Disclosure of Interests:

Christina Bergmann: None declared, Jörg H.W. Distler Speakers bureau: Actelion, Anamar, ARXX, Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Christoph Treutlein: None declared, Koray Tascilar Speakers bureau: Gilead sciences GmbH, Pfizer Turkey, UCB Turkey, Anna-Theresa Mueller: None declared, Armin Atzinger: None declared, Alexandru-Emil Matei: None declared, Johannes Knitza: None declared, Andrea-Hermina Györfi: None declared, Anja Lueck: None declared, Clara Dees: None declared, Alina Soare: None declared, Andreas Ramming: None declared, Verena Schönau: None declared, Oliver Distler Speakers bureau: Arxx Therapeutics, Baecon Discovery, Blade Therapeutics,Bayer, Böhringer Ingelheim, Catenion,Competitive Drug Development International Ltd, Corbuspharma, CSL Behring, ChemomAb, Horizon Pharmaceuticals, Ergonex, Galaapagos NV, Glenmark Pharmaceuticals,GSK, Inventiva, Italfarmaco, IQvia, Kymera, Lilly, Medac, Medscape, MSD, Novartis, Pfizer, Roche, Sanofi, Taget Bio Sciencec, UCB, Grant/research support from: Bayer,Böhringer Ingelheim, Mitsubishi Tanabe Pharma, Olaf Prante: None declared, Philipp Ritt: None declared, Theresa Ida Goetz: None declared, Markus Koehner: None declared, Michael Cordes: None declared, Tobias Baeuerle: None declared, Torsten Kuwert Speakers bureau: Honoraria for occasional lectures by Siemens Healthineers, Grant/research support from: Research grant to the Clinic of Nuclear Medicine by this entity covering projects in the field of SPECT/CT, Georg Schett: None declared, Christian Schmidkonz: None declared

AB0420 CIRCULATING MONOCYTES HAVE DISTINCT PHYSICAL PROPERTIES THAT CORRELATE WITH DISEASE ACTIVITY AND SEVERITY AND PREDICT PROGRESSION IN SYSTEMIC SCLEROSIS

Background:

Systemic sclerosis (SSc) is associated with high morbidity and is one of the autoimmune rheumatic diseases with the highest mortality. However, tools to evaluate disease activity, response to treatment or to predict disease progression are scarce. Dysregulated immune responses are major pathogenic players at the onset and in the progression of SSc. Recent evidence demonstrates that mechanical properties of circulating leukocytes reflect their states and functions, and during activation ensure their adaptation to the changing physical requirements (e.g. softening to extravasate and migrate in the tissues) (1). Real-time fluorescence and deformability cytometry (RT-FDC) is a novel technique that allows the identification of cells from a heterogenous population by marker expression, with their subsequent mechanical phenotyping in a high-throughput manner (2, 3).

Objectives:

Here we characterized the physical properties of circulating immune cells in SSc patients, aiming to identify disease-related changes in their phenotypes, clinical correlates of these changes and their potential to predict disease progression.

Methods:

51 patients fulfilling the 2013 ACR/EULAR classification criteria for SSc and 17 age- and sex-matched healthy controls were included in the study. Blood was collected from the donors between 05.2019 and 10.2020. Peripheral blood mononuclear cells (PBMCs) were isolated and stained with antibodies against major circulating lymphoid (CD8+, CD4+ T cells, B cells, NK cells, NKT-like cells) and myeloid subpopulations (classical, intermediate and inflammatory monocytes, conventional dendritic cells and plasmacytoid dendritic cells). Each subpopulation was identified in RT-FDC by standard gating based on its marker expression and its area, deformation and apparent Young’s modulus (a measure of cell stiffness) were determined. The analysis was conducted using a custom Python script. For the patients included, demographic and clinical data were collected at every visit. Correlations with clinical parameters were analyzed in R.

Results:

All three subpopulations of monocytes identified by expression of HLA-DR, CD14 and/or CD16 had higher deformation and cross-sectional area in SSc patients as compared to healthy controls. From the SSc patients, monocytes had higher deformation and area in those with diffuse cutaneous SSc, extensive lung fibrosis and active disease as compared to those with limited cutaneous SSc, limited lung fibrosis and stable disease, respectively. Moreover, monocyte deformation and area significantly correlated with the EUSTAR activity index, with mRSS, with the extent of lung involvement on HR-CT (positive correlation), with DLCO and FVC (negative correlation). Follow-up data collected one year after the measurements showed that a higher monocyte deformation and cross-sectional area at baseline predicts future progression of lung disease, defined according to the INBUILD study, as well as future progression of skin fibrosis.

Conclusion:

We demonstrated that circulating subsets of monocytes in SSc patients show an increase in deformation and cross-sectional area, that these changes correlate with current disease activity and can identify patients with high risk of future progression of skin or lung fibrosis. These changes might reflect an activated state of circulating monocytes in SSc that facilitate their tissue migration. Mechanical phenotyping of monocytes by RT-FDC might thus serve as a useful tool for clinical evaluation of SSc patients.

References:

[1]Bashant KR, Toepfner N, Day CJ, Mehta NN, Kaplan MJ, Summers C, et al. The mechanics of myeloid cells. Biol Cell. 2020;112(4):103-12.

[2]Otto O, Rosendahl P, Mietke A, Golfier S, Herold C, Klaue D, et al. Real-time deformability cytometry: on-the-fly cell mechanical phenotyping. Nat Methods. 2015;12(3):199-202, 4 p following.

[3]Rosendahl P, Plak K, Jacobi A, Kraeter M, Toepfner N, Otto O, et al. Real-time fluorescence and deformability cytometry. Nat Methods. 2018;15(5):355-8.

Disclosure of Interests:

Alexandru-Emil Matei: None declared, Kubánková Markéta: None declared, Andrea-Hermina Györfi: None declared, Evgenia Boxberger: None declared, Despina Soteriou: None declared, Maria Papava: None declared, Julia Muth: None declared, Martin Kräter: None declared, Georg Schett: None declared, Jochen Guck: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Employee of: Stock owner of 4D Science and Scientific head of FibroCure

AB0091 INHIBITION OF AUTOPHAGY PREVENTS PROGRESSION OF FIBROSIS IN MURINE MODELS OF SYSTEMIC SCLEROSIS

Background:

Autophagy is catabolic process allowing cells to degrade unnecessary or dysfunctional cellular organelles. Failure of appropriate regulation of autophagy, however, can severely perturb tissue homeostasis. Recent studies demonstrate that autophagy is activated in several fibrotic diseases such as liver fibrosis, renal interstitial fibrosis, cardiac fibrosis.

Objectives:

The objective of this work was to characterize the activation of autophagy in systemic sclerosis (SSc) and to decipher its role in the pathogenesis of SSc.

Methods:

Activation of autophagy in skin samples of patients and murine models of SSc was assessed by co-staining of LC3B and P62 with the lysosomal marker LAMP2. The role of the autophagy was investigated in the model of bleomycin-induced dermal fibrosis. Beclin1 was overexpressed using adenovirus encoding for Beclin1. To knockdown Atg7 in vivo was achieved by subcutaneous injections of Atg7 siRNA or non-targeting siRNA. In vivo, 3-methyladenine (3-MA) was administered i.p. in a concentration of 15 mg/kg ones daily. Protein expression was measured by Western blot. Target genes were analyzed by qPCR. To monitor the autophagic flux, we generated adenoviral vectors encoding for tandem fluorescent-tagged LC3 (mRFP-EGFP-LC3).

Results:

In the present study, we demonstrate that autophagy is activated in fibroblasts in SSc skin and also in experimental fibrosis models as compared to respective non-fibrotic control tissue with enhanced activity in in vivo and in vitro autophagy reporter studies. The aberrant activation of autophagy had profound stimulatory effects on fibroblasts. Activation of autophagy by forced expression of BECLIN1 promoted fibroblast-to-myofibroblast transition and stimulated the collagen release by cultured human fibroblasts and induced fibrosis in murine model. Nevertheless, inhibition of autophagy can deactivate myofibroblasts and induce regression of tissue fibrosis. Knockdown of ATG7 or BECLIN1 in human fibroblasts reduced the expression of αSMA and the number of stress fibers in myofibroblasts, indicating re-differentiation of myofibroblasts into resting fibroblasts upon inhibition of autophagy. Similar results were obtained with the autophagy inhibitors CQ and 3-MA. In vivo, siRNA mediated knockdown of Atg7 effectively prevented progression of fibrosis in a model of established bleomycin-induced skin fibrosis. Inactivation of autophagy decreased dermal thickness, myofibroblast counts and hydroxyproline content to below pretreatment levels, indicating regression of bleomycin-induced skin fibrosis. In addition, treatment of mice with the autophagy inhibitor 3-MA ameliorated bleomycin-induced skin fibrosis.

Conclusion:

We demonstrate that autophagy activity is enhanced in fibroblasts of SSc patients and in murine models of SSc. The increased activation of autophagy induces fibroblast-to-myofibroblast transition and promotes fibrotic tissue remodeling. However, inhibition of autophagy can deactivate myofibroblasts and induce regression of tissue fibrosis.

References:

[1]Wynn, T. Cellular and molecular mechanisms of fibrosis. J Pathol 214, 199-210 (2008).

[2]Klionsky DJ, Abeliovich H, Agostinis P, et al. Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes. Autophagy 4, 151-175 (2008).

[3]Wang, CW & Klionsky, DJ. The molecular mechanism of autophagy. Mol Med 9, 65-76 (2003).

[4]Hernández-Gea V, Ghiassi-Nejad Z, Rozenfeld R, et al. Autophagy releases lipid that promotes fibrogenesis by activated hepatic stellate cells in mice and in human tissues. Gastroenterology 142, 938-946 (2012).

Disclosure of Interests:

Ariella Zehender: None declared, Yi-Nan Li: None declared, Neng-Yu Lin: None declared, Andrea-Hermina Györfi: None declared, Alina Soare: None declared, Christina Bergmann: None declared, Andreas Ramming: None declared, Georg Schett: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB., Grant/research support from: Anamar, Active Biotech, Array Biopharma, aTyr, BMS, Bayer Pharma, Boehringer Ingel-heim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB., Employee of: stock owner of 4D Science and Scientific head of FibroCure

POS0861 EFFECTIVENESS AND SAFETY OF TOCILIZUMAB IN PATIENTS WITH SYSTEMIC SCLEROSIS: A PROPENSITY SCORE CONTROL MATCHED OBSERVATIONAL STUDY OF THE EUSTAR COHORT

Background:

Tocilizumab (TCZ) showed trends for improving skin fibrosis and prevented progression of lung fibrosis in patients with systemic sclerosis (SSc) in placebo-controlled randomised clinical trials (RCTs). However, safety and effectiveness of TCZ beyond these selected and enriched clinical trial populations in SSc is still unknown.

Objectives:

To assess safety and effectiveness of TCZ treatment compared to standard of care in SSc patients from the large, multicentre, observational, real-life EUSTAR network/database using propensity score matching.

Methods:

SSc patients from the EUSTAR network/database, who fulfilled the ACR/EULAR 2013 classification criteria, with a baseline and a follow-up visit at 12±3 months, receiving TCZ or standard of care (controls), were selected. The following variables were used for the propensity score matching (1:1): age at diagnosis, gender, disease subtype, baseline modified Rodnan skin score (mRSS), forced vital capacity (FVC), and diffusing capacity for carbon monoxide (DLCO), co-therapy with immunosuppressives, disease duration, and year of treatment. Primary endpoints were mRSS and FVC at 12±3 months follow-up compared between the groups, using paired t-tests. Secondary endpoints were the percentage of progressive/regressive patients for skin and lung at 12±3 months follow-up according to standard definitions (1,2). Sensitivity analyses assessed pre-processing decisions (selection of most recent vs. random observation for control patients with multiple suitable time intervals), as well as the matching method (optimal vs. exact matching). Missing values were addressed with 100-fold multiple imputation using chained equations. Safety data were analysed in all patients. The study including the statistical analysis plan was pre-registered at www.drks.de (DRKS-ID: DRKS00015537).

Results:

We identified 93 SSc patients treated with TCZ and 2370 SSc patients with standard of care who fulfilled the inclusion criteria. Forty nine (57.7%) of the TCZ treated patients were diffuse, eight patients were not classified, disease duration was (mean±SD) 6.35±5.40 years, their baseline mRSS was 15.05±10.85, and 76 (81.7%) received immunosuppressive therapy in addition to TCZ.Through multiple imputation and propensity score matching, 100 imputed sets of 93 pairs of TCZ/controls were generated. Comparison between groups showed consistent effects of TCZ across all pre-defined primary and secondary endpoints: mRSS was lower in the TCZ group (mean difference (95% confidence interval (CI)) -1.8 (-4.79 to 1.19), p=0.24, Figure 1A). Similarly, FVC % predicted was higher in the TCZ group mean difference (2.25, 95% CI -4.57 to 9.06), p=0.51, Figure 1B). Considering secondary endpoints, the percentage of skin progressors as well as lung progressors at follow up was lower in the TCZ group (odds ratio OR 0.67 (95% CI 0.07 to 6.41), p=0.74 and OR 0.53 (95% CI 0.16 to 1.7); p=0.2, respectively. Consistently, the percentage of regressors for skin (OR 1.6 (95% CI 0.56 to 4.54), p=0.38) and for lung (OR 1.74 (95% CI 0.66 to 4.58), p=0.26) was higher in TCZ. These results were robust regarding the sensitivity analyses. Safety analysis confirmed previously reported adverse event profiles.

Conclusion:

In this large, observational, controlled, real-life EUSTAR study, effectiveness of TCZ did not reach statistical significance compared to standard of care treatment but showed consistent positive effects of TCZ on skin and lung fibrosis across all pre-defined primary and secondary endpoints confirming data from recent RCTs.

References:

[1]Prediction of improvement in skin fibrosis in diffuse cutaneous systemic sclerosis: a EUSTAR analysis. Ann Rheum Dis 2016:1743-8.

[2]Progressive interstitial lung disease in patients with systemic sclerosis-associated interstitial lung disease in the EUSTAR database. Ann Rheum Dis 2021:219-227.

Disclosure of Interests:

Simon Kuster: None declared, Suzana Jordan: None declared, Muriel Daniele Elhai: None declared, Ulrike Held: None declared, Klaus Steigmiller: None declared, Cosimo Bruni: None declared, Florenzo Iannone: None declared, Serena Vettori: None declared, Elise Siegert: None declared, Simona Rednic: None declared, Veronica Codullo: None declared, Paolo Airò Consultant of: Dr. Airo’ reports personal fees (consultancies) from Bristol Myers Squibb, Bohringer Ingelheim, non-financial support from CSL Behring, SOBI, Janssen, Roche, Sanofi, Pfizer, Yolanda Braun-Moscovici: None declared, Nicolas Hunzelmann: None declared, Maria Joao Salvador: None declared, Valeria Riccieri: None declared, Ana Maria Gheorghiu: None declared, Juan Jose Alegre Sancho: None declared, Katarzyna Romanowska-Prochnicka: None declared, Ivan Castellví: None declared, Ina Koetter: None declared, Marie-Elise Truchetet Consultant of: Marie-Elise Truchetet has had consultancy relationships and/or has received research funding from Boehringer Ingelheim, Genentech/Roche, and Sanofi in the area of potential treatments of scleroderma and its complications., Grant/research support from: Marie-Elise Truchetet has had consultancy relationships and/or has received research funding from Boehringer Ingelheim, Genentech/Roche, and Sanofi in the area of potential treatments of scleroderma and its complications., Francisco J López-Longo: None declared, Pavel Novikov: None declared, Alessandro Giollo: None declared, Yuichiro Shirai: None declared, Laura Belloli: None declared, Elisabetta Zanatta: None declared, Eric Hachulla: None declared, Vanessa Smith: None declared, Christopher Denton: None declared, Ruxandra Ionescu: None declared, Tim Schmeiser: None declared, Jörg H.W. Distler: None declared, Armando Gabrielli: None declared, Anna-Maria Hoffmann-Vold Consultant of: AMHV has received research funding and/or consulting fees and/or other remuneration from Actelion, Boehringer Ingelheim, Roche, Bayer, Merck Sharp & Dohme, ARXX, Lilly and Medscape, Grant/research support from: AMHV has received research funding and/or consulting fees and/or other remuneration from Actelion, Boehringer Ingelheim, Roche, Bayer, Merck Sharp & Dohme, ARXX, Lilly and Medscape. Masataka Kuwana: None declared, Yannick Allanore: None declared, Oliver Distler Speakers bureau: Oliver Distler has/had consultancy relationship and/or has received research funding in the area of potential treatments for systemic sclerosis and its complications from (last three years): Abbvie, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Baecon Discovery, Blade Therapeutics, Bayer, Boehringer Ingelheim, ChemomAb, Corbus Pharmaceuticals, CSL Behring, Galapagos NV, Glenmark Pharmaceuticals, GSK, Horizon (Curzion) Pharmaceuticals, Inventiva, iQvia, Italfarmaco, iQone, Kymera Therapeutics, Lilly, Medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Novartis, Pfizer, Roche, Sanofi, Serodapharm, Topadur, Target Bioscience and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Consultant of: Oliver Distler has/had consultancy relationship and/or has received research funding in the area of potential treatments for systemic sclerosis and its complications from (last three years): Abbvie, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Baecon Discovery, Blade Therapeutics, Bayer, Boehringer Ingelheim, ChemomAb, Corbus Pharmaceuticals, CSL Behring, Galapagos NV, Glenmark Pharmaceuticals, GSK, Horizon (Curzion) Pharmaceuticals, Inventiva, iQvia, Italfarmaco, iQone, Kymera Therapeutics, Lilly, Medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Novartis, Pfizer, Roche, Sanofi, Serodapharm, Topadur, Target Bioscience and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Grant/research support from: The study was partially supported by a grant from Roche. Roche was not involved in analysis or interpretation of the results.

AB0410 S100A4 PLASMA LEVELS CORRELATE WITH DISEASE ACTIVITY, SKIN FIBROSIS AND INTERSTITIAL LUNG DISEASE IN SYSTEMIC SCLEROSIS PATIENTS

Background:

In our previous study we demonstrated that S100A4 is overexpressed in scleroderma (SSc) skin, SSc fibroblasts and preclinical models of SSc in a TGF-β dependent manner. We showed that S100A4 is a new regulator of TGF-β signalling and its inhibition prevents the pro-fibrotic effects of TGF-β. Inactivation of S100A4 prevented dermal fibrosis induced by bleomycin and in Tsk-1 mice

Objectives:

The aim of this study was to evaluate S100A4 in the peripheral blood of SSc patients and characterize its potential association with SSc-related features.

Methods:

A total of 33 patients (29 females; mean age 52.8; disease duration 4.2 years; dcSSc/lcSSc = 8/25) who met the 2013 EULAR/ACR classification criteria for SSc and 20 healthy age- and sex-matched individuals were included in this study. Plasma levels of S100A4 were measured using ELISA (CUSABIO, Houston, USA). Data are presented as median (IQR).

Results:

S100A4 plasma levels were significantly increased in SSc patients compared to healthy controls (78.6(32.3-146.5) vs. 43.4(32.3-53.4)ng/mL,p=0.011). Patients with diffuse cutaneous (dc)SSc had significantly higher levels of S100A4 than patients with limited cutaneous (lc)SSc or healthy controls (168.5(81.5-347.5) vs. 63.4(30.9-130.6),p=0.017,p=0.001, respectively). Plasma levels of S100A4 positively correlated with mRSS (r=0.556,p=0.001). Furthermore, S100A4 negatively correlated with forced vital capacity (FVC) and peripheral oxygen saturation (SpO2) (r=- 0.362,p=0.038;r=-0.414,p=0.029, respectively). S100A4 levels positively correlated with ESSG activity score (r=0.750,p<0.001). However, only correlations between S100A4 and mRSS, and ESSG activity score were approved at corrected level of statistical significance after Bonferroni’s correction (p<0.01). In a prospective analysis of patients (n=40) with progressive SSc-ILD treated with 6 (n=24) or 12 (n=16) monthly i.v. pulses of cyclophosphamide (CPA, 500 mg/m2), we observed a significant decrease in plasma S100A4 levels between the baseline samples (month 0) and blood drawn after 6 months of CPA treatment (76.3(52.9–98.6) vs. 73.2(44.4–98.6)ng/mL,p=0.013). Furthermore, baseline S100A4 levels predicted the change (m0-m6) in CRP and ESR levels after 6 months of CPA therapy (r=0.472,p=0.004;r=0.528,p=0.003, respectively).

Conclusion:

We demonstrate that plasma S100A4 levels are significantly increased in SSc patients compared with healthy controls. Increased S100A4 is associated with the dcSSc subset, skin involvement, deteriorated parameters of interstitial lung disease and higher disease activity. In patients with progressive SSc-ILD, S100A4 declines after 6 months of cyclophosphamide therapy and predicts the systemic inflammatory response. These data further support our previous findings on the role of S100A4 as a regulator of TGF-β induced fibrosis in SSc.

Acknowledgements:

Supported by MHCR023728, SVV–260373.

Disclosure of Interests:

None declared

POS0835 DECLINE IN FORCED VITAL CAPACITY (FVC) IN SUBJECTS WITH SYSTEMIC SCLEROSIS-ASSOCIATED INTERSTITIAL LUNG DISEASE (SSC-ILD) IN THE SENSCIS TRIAL VERSUS HYPOTHETICAL REFERENCE SUBJECTS WITHOUT LUNG DISEASE

Background:

In the randomized SENSCIS trial in subjects with SSc-ILD, nintedanib reduced the rate of decline in FVC over 52 weeks (mL/year) by 44% compared to placebo. Healthy individuals have varied FVC depending on age, sex, ethnicity and height; expected values can be determined using internationally recognised reference equations.

Objectives:

To provide further context to the FVC declines observed in the SENSCIS trial, we compared the decline in FVC observed in subjects with SSc-ILD in the SENSCIS trial with the decline in FVC that would be expected in hypothetical subjects without ILD matched for age, sex, ethnicity and height.

Methods:

The SENSCIS trial enrolled subjects with SSc-ILD aged ≥18 years with first non-Raynaud symptom ≤7 years before screening, extent of fibrotic ILD ≥10% on HRCT, FVC ≥40% predicted and DLco 30–89% predicted. Baseline FVC (mL) and changes in FVC (mL) at week 52 were assessed in the nintedanib and placebo groups, with missing values at week 52 imputed using predictions from the primary analysis model (random slope and intercept model). Changes in FVC in the SENSCIS trial were compared to values in hypothetical healthy reference subjects matched to the SENSCIS subjects for age, sex, ethnicity and height. FVC values in these healthy reference subjects were derived from the equations published by the European Respiratory Society Global Lung Function Initiative in 2012, which were derived from data from over 70,000 subjects.1

Results:

In the nintedanib and placebo groups of the SENSCIS trial, respectively, mean (SD) time since onset of first non-Raynaud symptom was 3.5 (1.6) and 3.5 (1.8) years. In the nintedanib group, mean (SD) FVC at baseline was 2460 (737) mL, compared with 3403 (787) mL in the healthy reference subjects. In the placebo group, mean (SD) FVC at baseline was 2544 (817) mL compared with 3516 (887) mL in the healthy reference subjects. The difference in the change from baseline in FVC at week 52 between the nintedanib-treated subjects in the SENSCIS trial (n=287) and the healthy reference subjects was 26.6 mL ([95% CI: 1.2, 52.0]; p=0.04). The difference in the change from baseline in FVC at week 52 between the placebo-treated subjects in the SENSCIS trial (n=286) and the reference subjects was 77.5 mL ([95% CI: 51.4, 103.7]; p<0.001) (Figure 1).

Conclusion:

Subjects with SSc-ILD who participated in the SENSCIS trial had marked lung function impairment at baseline compared with healthy matched reference subjects, despite a mean duration of SSc of 3.5 years. Over 52 weeks, the decline in FVC in subjects with SSc-ILD who received placebo was 4-fold greater than in healthy reference subjects. Subjects with SSc-ILD who were treated with nintedanib had a decline in FVC that was only slightly greater than the decline observed in the matched healthy subjects. These data support the clinical relevance of the reduction in the rate of FVC decline provided by nintedanib in patients with SSc-ILD.

References:

[1]Quanjer et al. Eur Respir J 2012;40:1324−43.

Acknowledgements:

The SENSCIS trial was funded by Boehringer Ingelheim. Medical writing support was provided by FleishmanHillard Fishburn, London, UK. The authors meet criteria for authorship as recommended by the International Committee of Medical Journal Editors (ICMJE).

Disclosure of Interests:

Toby Maher Speakers bureau: Boehringer Ingelheim and Roche/Genentech, Consultant of: Acelleron Pharma, AstraZeneca, Boehringer Ingelheim, Bristol-Myers Squibb, GlaxoSmithKline and Roche/Genentech, Arnaud Bourdin Speakers bureau: Actelion/Janssen (personal fees and other), AstraZeneca (personal fees and other), Boeringher Ingelheim (personal fees and other), Chiesi (personal fees and other), GlaxoSmithKline (personal fees and other), Novartis (personal fees and other), Pulsar Therapeutics (other), Roche (personal fees and other), Sanofi Regeneron (personal fees and other), Teva (other) and United Therapeutics (other), Consultant of: Actelion/Janssen (personal fees and other), AstraZeneca (personal fees and other), Boeringher Ingelheim (personal fees and other), Chiesi (personal fees and other), GlaxoSmithKline (personal fees and other), Novartis (personal fees and other), Pulsar Therapeutics (other), Roche (personal fees and other), Sanofi Regeneron (personal fees and other), Teva (other) and United Therapeutics (other), Grant/research support from: Actelion/Janssen (grants and other), AstraZeneca (grants and other), Boeringher Ingelheim (grants and other), Chiesi (other), GlaxoSmithKline (grants and other), Novartis (other), Pulsar Therapeutics (other), Roche (other), Sanofi Regeneron (other), Teva (other) and United Therapeutics (other), Elizabeth Volkmann Consultant of: Boehringer Ingelheim, Grant/research support from: Corbus and Forbius, Serena Vettori Paid instructor for: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Jörg H.W. Distler Speakers bureau: Actelion, Active Biotech, AnaMar, Arxx Therapeutics, Bayer, Boehringer Ingelheim, Celgene, Galapagos NV, GlaxoSmithKline, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Consultant of: AnaMar, Arxx Therapeutics, Bayer, Boehringer Ingelheim, Galapagos NV, Inventiva, JB Therapeutics and UCB, Grant/research support from: Active Biotech, AnaMar, Array BioPharma, Arxx Therapeutics, aTyr, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Galapagos NV, GlaxoSmithKline, Inventiva, Novartis, Sanofi-Aventis, Redx and UCB, Margarida Alves Employee of: Currently an employee of Boehringer Ingelheim, Christian Stock Employee of: Currently an employee of Boehringer Ingelheim, Oliver Distler Consultant of: AbbVie, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Baecon Discovery, Bayer, Blade Therapeutics, Boehringer Ingelheim, ChemomAb, Corbus, CSL Behring, Galapagos NV, GlaxoSmithKline, Glenmark Pharmaceuticals, Horizon (Curzion) Pharmaceuticals, Inventiva, IQVIA, Italfarmaco, iQone, Kymera Therapeutics, Lilly, Medac, Medscape, Merck Sharp & Dohme, Mitsubishi Tanabe Pharma, Novartis, Pfizer, Roche, Sanofi, Serodapharm, Target Bioscience, Topadur Pharma and UCB, Grant/research support from: Kymera Therapeutics and Mitsubishi Tanabe Pharma

OP0242 EFFECTS OF THE AUTOTAXIN INHIBITOR ZIRITAXESTAT ON SKIN AND LUNG FIBROSIS IN A MURINE GRAFT-VERSUS-HOST DISEASE MODEL OF SYSTEMIC SCLEROSIS

Background:

There is an unmet medical need for new drugs to treat systemic sclerosis (SSc). Autotaxin (ATX) is a widely expressed enzyme that regulates diverse cellular processes, including proliferation, differentiation and migration, and has been implicated in the pathogenesis of SSc. Targeting ATX is a promising new strategy for treating SSc. The autotaxin inhibitor ziritaxestat (GLPG1690) is a potential first-in-class disease-modifying drug for SSc that has been shown to improve skin score in the Phase 2a NOVESA (NCT03798366) trial in patients with SSc.

Objectives:

To investigate the effects of ziritaxestat in a chronic graft-versus-host disease (cGvHD) murine model of SSc.

Methods:

Effects of ziritaxestat (10 or 30 mg/kg twice daily [bid]) on disease activity were assessed in a cGvHD murine model of SSc (allogeneic bone marrow transplantation [BMT] with B10.D2 donor and BALB/c recipient; syngeneic mice as controls). Ziritaxestat or nintedanib (60 mg/kg once daily [qd]) as active comparator was administered 21 d after BMT and continued for 35 d. Effects of ziritaxestat were assessed by clinical monitoring, histologic assessment of skin and lungs (dermal thickness, Ashcroft scores and collagen-covered area), immunofluorescence staining with Trichrome and Sirius Red for myofibroblasts, and biochemical analysis of collagen content, as measured by hydroxyproline levels.

Results:

Ziritaxestat 30 mg/kg bid for 35 days significantly reduced the clinical cutaneous score in the murine cGvHD model by 57% (p<0.05) compared with vehicle, and to a similar extent when compared with nintedanib 60 mg/kg (38%; p<0.05). Dermal accumulation of collagen and dermal thickness (Figure) were reduced with ziritaxestat 10 and 30 mg/kg compared with vehicle. At 30 mg/kg, ziritaxestat reversed the increase in the allogeneic model (p<0.001), returning dermal thickness to the levels in non-fibrotic control mice. Ziritaxestat also significantly reduced pulmonary fibrosis in the cGvHD model, with reductions in the fibrotic lung area (ziritaxestat 10 and 30 mg/kg; p<0.001 for both) and Ashcroft scores (ziritaxestat 30 mg/kg; p<0.05). Ziritaxestat was generally well tolerated.

Conclusion:

Ziritaxestat improved the histological, biochemical and clinical symptom readouts of dermal and pulmonary fibrosis in a murine model, consistent with a broad and rapid disease-modifying effect in SSc.

Acknowledgements:

This study was funded by Galapagos NV (Mechelen, Belgium). Medical writing/editorial support was provided by Ian Faulkner, PhD (Aspire Scientific, Bollington, UK) funded by Galapagos NV.

Disclosure of Interests:

Yun Zhang Employee of: 4D Science, Lena Summa Employee of: 4D Science, Bertrand Heckmann Shareholder of: Galapagos, Employee of: Galapagos, Jörg H.W. Distler Shareholder of: 4D Science, Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GlaxoSmithKline, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, Bristol Myers Squibb, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GlaxoSmithKline, Inventiva, Novartis, Sanofi-Aventis, RedX and UCB

OP0245 ANTI-S100A4 MONOCLONAL ANTIBODY TREATMENT AMELIORATES SKIN FIBROSIS IN INFLAMMATORY AND NON-INFLAMMATORY PRE-CLINICAL MODELS OF SYSTEMIC SCLEROSIS

Background:

AX-202 is a monoclonal antibody that inhibits the bioactivity of S100A4. S100A4 is an alarm signal that is released from cells in response to stress or injury and functions as an amplifying mechanism of inflammation and fibrosis in the diseased tissue microenvironment. Previous in vitro studies have found that S100A4 induces fibroblast activation, sensitizes fibroblasts to the effects of TGFβ, drives epithelial-mesenchymal transition, and stimulates monocyte cytokine release (1-3). Moreover, S100A4-/- mice are protected from fibrosis in several animal models (1). In patients with systemic sclerosis (SSc), S100A4 is elevated both in lesional tissue and systemically and correlates with skin involvement, disease activity, and pulmonary function.

Objectives:

The aim of this study was to assess the antifibrotic effects of murine AX-202 in two pre-clinical models of SSs reflecting both inflammation-mediated and inflammation non-mediated fibrosis and confirm the in vivo activity of humanized AX-202.

Methods:

We first evaluated the effects of murine AX-202 in the bleomycin-induced skin fibrosis model and the tight-skin 1 (Tsk-1) model. In the bleomycin (BLM) model, fibrosis was induced by 3 weeks of BLM s.c. injections followed by 3 weeks of AX-202 treatment in parallel with continued BLM s.c. injections. The control groups included NaCl s.c. injections for 6 weeks, BLM s.c. injections for 6 weeks, or BLM s.c. injections for 3 weeks, followed by NaCl s.c. injections for 3 weeks. Three dosing regimens of AX-202 were tested: 3.75, 7.5, or 12.5 mg/kg i.p. every 3rd day. In the Tsk-1 model, treatment with 7.5 mg/kg i.p. every 3rd day was administered from week 5 until week 10. The control groups included pa mice, Tsk-1 mice, and Tsk-1 mice treated i.p. with isotype IgG. We subsequently evaluated the effects of humanized AX-202 in the model of BLM-induced skin fibrosis in a similar design as used for the murine AX-202 study. Three dosing regimens were tested: 8 mg/kg and 16 mg/kg i.p. every 3rd day and 24 mg/kg i.v. once weekly.

Results:

In the BLM model, murine AX-202 (7.5 mg/kg) was effective both in the prevention of progression of pre-established skin fibrosis and in the induction of regression of fibrosis as assessed by the dermal thickness (-55%, p<0.0001 vs BLM for 6 weeks, and -23%, p<0.0001 vs BLM for 3 weeks), myofibroblast count and hydroxyproline content. Murine AX-202 also ameliorated fibrosis in the Tsk-1 model as assessed by the hypodermal thickness (-24%, p=0.01 vs Tsk-1 isotype control), myofibroblast count, and hydroxyproline content. In both models, the antifibrotic effects were associated with a reduction in pSMAD3 expression. Humanized AX-202 was effective in the prevention of progression of pre-established skin fibrosis in all doses tested across all endpoints (dermal thickness, myofibroblast counts, hydroxyproline content). In the two groups treated with 16 mg/kg i.p. and 24 mg/kg i.v., humanized AX-202 also induced regression of fibrosis (-83%, p<0.001, and -61%, p<0.001 vs BLM for 3 weeks, respectively). Both murine and humanized AX-202 were well tolerated in all study groups in both models.

Conclusion:

We demonstrate that AX-202 confers potent antifibrotic effects in complementary models of SSc. These results confirm and expand previous data showing that inhibition of S100A4 by AX-202 is a promising potential therapeutic candidate for disease modification in SSc or other fibrotic conditions.

References:

[1]Tomcik M et al. S100A4 amplifies TGF-beta-induced fibroblast activation in systemic sclerosis. Ann Rheum Dis. 2015;74(9):1748-55.

[2]Cerezo LA et al. The metastasis-associated protein S100A4 promotes the inflammatory response of mononuclear cells via the TLR4 signalling pathway in rheumatoid arthritis. Rheumatology (Oxford). 2014;53(8):1520-6.

[3]Fei F, et al. Role of metastasis-induced protein S100A4 in human non-tumor pathophysiologies. Cell Biosci. 2017;7:64.

Acknowledgements:

The study was supported by Arxx Therapeutics and MHCR 023728.

Disclosure of Interests:

Michal Tomčík: None declared, Thuong Trinh-Minh: None declared, Cuong Tran Manh: None declared, Hana Štorkánová: None declared, Lenka Štorkánová: None declared, Ladislav Šenolt: None declared, Jörg Klingelhöfer Employee of: Arxx Therapeutics, Rizwan I Hussain Employee of: Arxx Therapeutics, Jonas Hallén Employee of: Arxx Therapeutics, Jörg H.W. Distler Shareholder of: the stock owner of 4D Science, Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

POS0855 PATIENT PREFERENCES, TRADE-OFFS AND ACCEPTABLE RISKS IN THE TREATMENT OF SYSTEMIC SCLEROSIS-ASSOCIATED INTERSTITIAL LUNG DISEASE: A STEP TOWARDS SHARED DECISION-MAKING

Background:

Current treatments for systemic sclerosis-associated interstitial lung disease (SSc-ILD) are characterised by different attributes such as mode of administration, adverse events (AE) and efficacy. Physicians and patients often have different perspectives on treatments, thus shared decision-making between patients and physicians is essential. An understanding of patients’ decision processes when weighing treatment attributes and the trade-offs they are willing to make is important for shared decision-making.

Objectives:

The study aimed to 1) identify relevant treatment attributes, 2) elicit patient preferences for these attributes and 3) quantify preference as relative attribute importance (RAI; a higher RAI indicates that more of the variability in patients’ responses may be explained by changes in the attribute); and maximum acceptable risk (MAR) of diarrhoea, nausea and/or vomiting (MAR is a trade-off measure that evaluates attributes in risk-equivalences as a unit of measurement).

Methods:

A discrete choice experiment (DCE) was created, based on a literature review, a patient advisory board, qualitative patient interviews, and a workshop involving SSc-ILD expert physicians. Seven SSc-ILD treatment attributes were identified: 1) mode of administration; 2) shortness of breath; 3) skin tightness; 4) cough; 5) tiredness; 6) risk of gastrointestinal tract (GIT) AEs; and 7) risk of serious and non-serious infections. The levels of AE risk were informed by frequencies observed in clinical trials and patient input during the interviews. The DCE was integrated into an online survey, which asked patients to make repeated choices between two alternatives described by varying levels of included attributes. Patients with SSc-ILD were recruited by physician referral from Switzerland, Norway, France, Germany and the USA. DCE data were analysed using a logit model, and RAI and MAR measures were calculated.

Results:

A total of 231 patients with physician-confirmed SSc-ILD (mean age 52.6±13.2 years; 54% diagnosed for >5 years) completed the survey. Patients with SSc-ILD mostly preferred twice-daily oral treatments (p<0.001) and infusion every 6–12 months (p<0.001) over monthly infusions. Patients’ choices were mostly affected by the risk of GIT AEs (RAI=25%; 95% CI 22–28%) and risk of infections (RAI=20%; 95% CI 16–24%). Improvements in shortness of breath and type and severity of cough were jointly more important than improvement in skin tightness (p<0.001).

Patients accepted an additional 21% risk (95% CI 13–29%) of GIT AEs if they could reduce the frequency of infusions from monthly to 6–12 monthly, or accepted an extra 15% (95% CI 7–23%) increase in risk if changing to an oral treatment twice daily. Among symptoms, an additional 28% (95% CI 20–36%) risk of GIT AEs was considered acceptable if the severity of patients’ persistent cough was reduced to a level that was easier to tolerate, even if it remained persistent. Similarly, a 37% (95% CI 28–46%) increase in the risk of GIT AEs was acceptable if it resulted in breathlessness during routine activities rather than breathlessness at rest. Finally, patients were willing to accept an additional 36% risk (95% CI 27–45%) of GIT AEs if it reduced their risk of non-serious infections from 30% to 15% and of serious infections from 10% to 5%.

Conclusion:

This is the first study to quantitatively elicit patients’ preferences for attributes of SSc-ILD treatments. Preferences were driven by safety, efficacy and technical considerations. Patients showed willingness to make trade-offs, providing a firm basis for shared decision-making in routine clinical practice.

Disclosure of Interests:

Cosimo Bruni Speakers bureau: Actelion, Consultant of: Eli Lilly, Grant/research support from: Gruppo Italiano Lotta alla Scleroderma (GILS), Fondazione Italiana per la Ricerca sull’Artrite (FIRA), New Horizon Fellowship, European Scleroderma Trial and Research (EUSTAR), Foundation for Research in Rheumatology (FOREUM)., Sebastian Heidenreich Consultant of: Sebastian Heidenreich, PhD is employed by Evidera Inc, a business unit of PPD. Evidera is a CRO that offers paid research services to pharmaceutical companies., Ashley Duenas Consultant of: Yes. I am an employee of Evidera which received funding from Boehringer Ingelheim for work related to this study., Anna-Maria Hoffmann-Vold Speakers bureau: Boehringer Ingelheim, Actelion, Roche, Merck Sharp & Dohme, Lilly, Consultant of: Actelion, Boehringer Ingelheim, Roche, Bayer, Merck Sharp & Dohme, ARXX, Lilly and Medscape, Grant/research support from: Boehringer Ingelheim, Armando Gabrielli Grant/research support from: Pfizer Bhering, Yannick Allanore Consultant of: Honorarium received from Boehringer, Medsenic,

Sanofi, Menarini, Grant/research support from: Grants received from Alpine, Ose Immunogenetics, Emmanuel Chatelus: None declared, Jörg H.W. Distler Shareholder of: JHWD is stock owner of 4D Science, Consultant of: JHWD has consultancy relationships with Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: JHWD has received research funding from Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB, Eric Hachulla: None declared, Vivian Hsu Speakers bureau: I am a speaker for Boehringer Ingelheim Pharmaceuticals, Consultant of: with Boehringer Ingelheim Pharmaceuticals, Grant/research support from: Principal Investigator for several clinical trials, currently with Genentech, Corbus Pharmaceutical, and EICOS, Nicolas Hunzelmann Speakers bureau: Boehringer, Roche, Sanofi, Dinesh Khanna Shareholder of: Eicos Sciences, Inc (less than 5%), Consultant of: Paid Consultant for: Acceleron, Actelion, Abbvie, Amgen, Bayer, Boehringer Ingelheim, CSL Behring, Corbus, Gilead, Galapagos, Genentech/Roche, GSK, Horizon, Merck, Mitsubishi Tanabe Pharma, Sanofi-Aventis, and United Therapeutics, Grant/research support from: Research Grant support from: Immune Tolerance Network, Bayer, BMS, Horizon, Pfizer, Employee of: Leadership/Equity position – Chief Medical Officer, CiviBioPharma/Eicos Sciences, Inc – recieves a stipend for role as Chief Medical Officer, which would technically qualify as emplyoment., Marie-Elise Truchetet Speakers bureau: Abbvie, Lilly, Sobi, Boehringer, Paid instructor for: Lilly, Consultant of: UCB, Sobi, Abbvie, Grant/research support from: UCB, Gilead, Ulrich Walker Shareholder of: Bayer, NASDAQ, MSCI-World ETF’s, Speakers bureau: All companies producing pharmaceuticals used in AIDS, Paid instructor for: Roche, Abbvie, Novartis, Consultant of: All companies producing pharmaceuticals used in AIDS, Grant/research support from: Gilead, Abbvie, (in the last two years). Other companies in previous years., Margarida Alves Employee of: Boehringer Ingelheim, Nils Schoof Employee of: Employee of Boehringer Ingelheim International GmbH, Lesley Ann Saketkoo Speakers bureau: Boehringer Ingelheim, Actelion, Janssen, Mallinckrodt, United Therapeutics, Consultant of: Actelion, Boehringer Ingelheim, Bayer, Bristol Meyer Squibb, Corbus, EICOS, Janssen, Horizon, United Therapeutics, Inc, Grant/research support from: Mallinckrodt, United Therapeutics, Oliver Distler Speakers bureau: Boehringer Ingelheim, Medscape, IQone, Roche, Consultant of: OD has/had consultancy relationship and/or has received research funding in the area of potential treatments for systemic sclerosis and its complications from (last three years):

Abbvie, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Baecon Discovery, Blade Therapeutics, Bayer, Boehringer Ingelheim, ChemomAb, Corbus Pharmaceuticals, CSL Behring, Galapagos NV, Glenmark Pharmaceuticals, GSK, Horizon (Curzion) Pharmaceuticals, Inventiva, iQvia, Italfarmaco, iQone, Kymera Therapeutics, Lilly, Medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Novartis, Pfizer, Roche, Sanofi, Serodapharm, Topadur, Target Bioscience and UCB. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Grant/research support from: Kymera Therapeutics, Mitsubishi Tanabe

POS0327 INACTIVATION OF ALDEHYDE DEHYDROGENASE 3A2 INHIBITS FIBROBLAST ACTIVATION AND TISSUE FIBROSIS

Background:

The aldehyde dehydrogenase (ALDH) superfamily composes a group of 20 enzymes that catalyze aldehyde oxidation. Within this enzyme family, ALDH3A2 stands out for its central role in the oxidation of long-chain aldehydes. Of particular interest, the substrates of ALDH3A2 include also profibrotic lipid mediators such as sphingosine 1-phosphate or leukotrienes, which have been reported to be deregulated in the context of SSc.

Objectives:

We aimed to investigate the role of ALDH3A2 in fibrotic tissue remodeling in SSc.

Methods:

Fibroblast-to-myofibroblast transition was analyzed by quantification of ACTA2/αSMA, by assessment of stress fiber formation and mRNA and protein levels of type I collagens. ALDH3A2/Aldh3a2 siRNAs were employed to specifically knockdown ALDH3A2 in dermal fibroblasts both in vitro and in vivo. Overexpression of ALDH3A2 was achieved by ALDH3A2-pcDNA transfection. The role of ALDH3A2 was investigated in three different mouse models: Bleomycin- and cGvHD-induced dermal fibrosis as well as fibrosis induced by overexpression of a constitutively active TGFβ receptor I (TBRICA). Target genes of ALDH3A2 in fibroblasts were identified by RNA sequencing.

Results:

The expression of ALDH3A2 was modestly reduced in dermal fibroblasts of SSc skin as compared to matched healthy controls. This reduction in ALDH3A2 expression was phenocopied by activation of TGFβ signaling, whereas selective inhibition of TGFβ signaling prevented the downregulation of ALDH3A2 in experimental fibrosis. ALDH3A2 overexpression promoted fibroblast-to-myofibroblast transition with increased levels of αSMA, enhanced formation of stress fibers and reduced collagen release. In contrast, knockdown of ALDH3A2 in dermal fibroblasts inhibited fibroblast activation and collagen release. Moreover, in vivo knockdown of ALDH3A2 in the skin of mice ameliorated dermal thickening, myofibroblast differentiation and collagen deposition in three different murine models of skin fibrosis: Bleomycin-induced skin fibrosis and sclerodermatous GvHD-as models of inflammatory stages of SSc and TBRICA-induced fibrosis as an inflammation-independent model of SSc. RNA sequencing of ALDH3A2-knockdown fibroblasts demonstrated that ALDH3A2 regulates the activity of a network of profibrotic developmental pathways including TGFβ, Wnt, Notch, and Hedgehog signaling.

Conclusion:

We demonstrate that ALDH3A2 regulates a network of profibrotic pathways to control fibroblast activation and tissue fibrosis. ALDH3A2 is modestly downregulated in SSc fibroblasts as result of an endogenous, TGFβ-driven feedback loop. Although this modest downregulation is not sufficient to counterbalance the aberrant fibroblast activation in SSc, augmentation of this endogenous regulation by knockdown of ALDH3A2 demonstrates potent antifibrotic potential in experimental dermal fibrosis, thereby providing first evidence for ALDH3A2 as a target for antifibrotic therapies.

Disclosure of Interests:

Xiaohan Xu: None declared, Yi-Nan Li: None declared, Chih-Wei Chen: None declared, Thuong Trinh-Minh: None declared, Georg Schett: None declared, Jörg H.W. Distler Consultant of: Actelion, Active Biotech, Anamar, ARXX, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, JB Therapeutics, Medac, Pfizer, RuiYi and UCB, Grant/research support from: Anamar, Active Biotech, Array Biopharma, ARXX, aTyr, BMS, Bayer Pharma, Boehringer Ingelheim, Celgene, Galapagos, GSK, Inventiva, Novartis, Sanofi-Aventis, RedX, UCB

[Digital ulcers in systemic sclerosis : A retrospective heath service study analysing treatment with bosentan and other vasoactive therapies]

BACKGROUND

Digital ulcers (DU) affect up to 60 % of patients with systemic sclerosis (SSc) and have a considerable impact on quality of life and morbidity. It is unclear to what extent authorised medicines are used, and if therapy guidelines are implemented in everyday practice.

METHOD

This retrospective health care study examined current standards of treatment for therapy and prevention of SSc-associated DU in an online survey with 83 physicians. Additionally, data from 161 case studies of SSc patients with DU were analysed, and the effect of DU treatment on the course of the disease determined.

RESULTS

For treatment and prevention of active DU, physicians predominantly indicated topical therapies, calcium channel blockers, iloprost and endothelin receptor antagonists. According to the case studies, 90 % of episodes with acute DU were treated with bosentan and iloprost in mono- or combination therapy. Preventive treatment was only administered during 50 % of episodes without DU, even after three or more phases with active DU. For the prevention of new DU, bosentan was used in mono- or combination therapy in 57 % of episodes without DU. Bosentan therapy during prevention shortened the following acute phase by 32 %. Additionally, continuous treatment with bosentan in acute and prevention phases reduced the duration of the following acute phase and increased the time to onset of new DU by 16 %. Moreover, bosentan stabilised the number of new DU.

CONCLUSION

In summary, these data confirm the efficacy of bosentan in preventing new DU when used in DU-free episodes and possibly also in phases of acute DU. Therapy recommendations for the treatment of DU are currently not fully implemented. In the future, even more attention should be paid to DU therapy.

Mechanisms of vascular damage in SSc--implications for vascular treatment strategies

Vascular abnormalities are a major component of SSc, but little is known about the events or mechanisms that initiate vascular injury and prevent its repair. In SSc, angiogenesis is incomplete or lacking despite the increased expression of a large array of pro-angiogenic factors such as VEGF. Conflicting results have recently been published concerning the presence and role of vasculogenesis and circulating endothelial progenitor cells in SSc. It remains to be established if these endothelial progenitor cells are a marker of endothelial disease or a cause of insufficient vascular repair. Human mesenchymal stem cells (MSCs) may be an alternative source for endothelial progenitor cells, and it has been observed that the angiogenic potential of endothelial-like MSCs is reduced. Other mechanisms of vascular damage include oxidative stress and factors released from activated platelets. In addition, growth factors such as ET-1 and PDGF induce proliferation of vascular smooth muscle cells resulting in intimal thickening. For the development of new therapeutic strategies, it is important to realize that the different vascular pathologies--uncompensated loss of capillaries on one hand and vascular remodelling with a proliferative vasculopathy on the other--might require different treatment approaches.

EULAR Scleroderma Trials and Research group statement and recommendations on endothelial precursor cells

Systemic sclerosis (SSc) is characterised by a progressive microangiopathy that contributes significantly to the morbidity of patients with SSc. Besides insufficient angiogenesis, defective vasculogenesis with altered numbers of endothelial precursor cells (EPCs) might also contribute to the vascular pathogenesis of SSc. However, different protocols for isolation, enrichment, culture and quantification of EPCs are currently used, which complicate comparison and interpretation of the results from different studies. The aim of the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) group expert panel was to provide recommendations for standardisation of future research on EPCs. Consensus statements and recommendations were developed in a face to face meeting by an expert panel of the basic science working group of EUSTAR. The findings were: cardiovascular risk factors and medications such as statins should be described in detail. A detailed description of methods considering isolation, culture, enrichment and detection of EPCs should be given. For in vitro culture of EPCs, no protocol has been shown to be superior to another, but coating with laminin and type IV collagen would resemble most closely the situation in vivo. The endothelial phenotype should be confirmed in all in vitro cultures at the end of the culture period. We recommend using CD133, vascular endothelial growth factor type 2 receptor (VEGFR2) and CD34 in combination with a viability marker for quantification of EPCs in the blood. Finally, exact standard operating procedures for fluorescence-activated cell sorting (FACS) analysis are given that should be strictly followed. In summary, the EUSTAR recommendations will help to unify EPC research and allow better comparison between the results of different studies.

The release of microparticles by apoptotic cells and their effects on macrophages

Microparticles are small membrane vesicles released from the cell membrane by exogenous budding. To elucidate the interactions of microparticles with macrophages, the effect of microparticles released from Jurkat T cells on RAW 264.7 cells was determined. Microparticles were isolated by differential centrifugation, using FACS analysis with annexin V and cell surface markers for identification. Various inducers of apoptosis increased the release of microparticles from Jurkat cells up to 5-fold. The released microparticles were then cultured with RAW 264.7 cells. As shown by confocal microscopy and FACS analysis, RAW 264.7 macrophages cleared microparticles by phagocytosis. In addition, microparticles induced apoptosis in RAW 264.7 cells in a dose-dependent manner with up to a 5-fold increase of annexin V positive cells and 9-fold increase in caspase 3 activity. Cell proliferation as determined by the MTT test was also reduced. Furthermore, microparticles stimulated the release of microparticles from macrophages. These effects were specific for macrophages, since no apoptosis was observed in NIH 3T3 and L929 cells. These findings indicate that microparticles can induce macrophages to undergo apoptosis, in turn resulting in a further increase of microparticles. The release of microparticles from apoptotic cells may therefore represent a novel amplification loop of cell death.

[Angiogenesis. Possibilities for therapeutic intervention in rheumatic diseases]

In contrast to vasculogenesis, angiogenesis is defined as the formation of new vessels from preexisting ones. Physiologically, this multistep process occurs in adults during the reproductive cycle and during pregnancy, pathophysiologically it can be found in wound healing, inflammation and carcinogenesis. The underlying mechanisms are vasodilatation and increasing permeability, destabilization of vessel walls and degradation of extracellular matrix, followed by the proliferation and migration of endothelial cells. Migrated endothelial cells form vascular tubes at sites of ischemia and these tubes are finally stabilized by pericytes and smooth muscle cells. This process is controlled by a complex interaction of angiogenic and angiostatic factors. In contrast to carcinogenesis, the role of angiogenesis for the pathogenesis and therapy of rheumatic diseases is less understood. Two examples for pathologically disturbed angiogenesis, rheumatoid arthritis and systemic sclerosis, are discussed in this review with respect to therapeutic options.

Angiogenesis and vasculogenesis in systemic sclerosis

In addition to inflammatory infiltrates and an accumulation of extracellular matrix proteins, vascular changes are a hallmark in the pathogenesis of systemic sclerosis (SSc). Consistent with the ongoing endothelial cell apoptosis, several markers of EC damage are up-regulated in the serum of SSc patients. Surprizingly, vascular endothelial growth factor (VEGF), a very potent angiogenic molecule, is overexpressed in SSc patients despite the insufficient angiogenesis. VEGF can protect patients from fingertip ulcers, but a prolonged overexpression of VEGF might have paradoxical effects leading to the formation of irregular vessels similar to that observed in SSc. Besides defective angiogenesis, recent studies suggest that vasculogenesis is also impaired in SSc patients with reduced numbers and functional defects of endothelial progenitor cells.

Vaskul�re Ver�nderungen in der Pathogenese der systemischen Sklerose

Systemic sclerosis (SSc, scleroderma) is a connective tissue disease of unknown etiology. Perivascular inflammatory infiltrates and endothelial apoptosis with an impaired angiogenesis are observed in early stages of the disease, whereas later stages are characterized by an excessive accumulation of extracellular matrix proteins in the skin and various internal organs. Consistent with the ongoing endothelial cell damage, various markers of endothelial cells such as endothelin-1, sICAM-1, s-VCAM-1 and thrombomodulin are found in high levels in the serum of SSc patients. Surprisingly, the vascular endothelial growth factor (VEGF), a potent angiogenic molecule, is overexpressed in the skin of patients with SSc despite insufficient angiogenesis. Interestingly, patients suffering from diffuse SSc and patients without finger tip ulcers show higher VEGF levels compared to age- and sex-matched controls. These results indicate that a controlled overexpression of VEGF might help to protect against the manifestation of ischemic conditions. On the other hand, data from animal models indicate that a long-term, uncontrolled overexpression of VEGF might have paradox effects on the formation of new vessels leading to capillary changes similar to those observed in SSc. In addition to the impaired angiogenesis, defective vasculogenesis might contribute to the vascular symptoms of SSc.

Angiogenic and angiostatic factors in the molecular control of angiogenesis

The vascular system that ensures an adequate blood flow is required to provide the cells with sufficient supply of nutrients and oxygen. Two different mechanisms of the formation of new vessels can be distinguished: vasculogenesis, the formation of the first primitive vascular plexus de novo and angiogenesis, the formation of new vessels from preexisting ones. Both processes are regulated by a delicate balance of pro- and anti-angiogenic factors. Physiologically, angiostatic mediators outweigh the angiogenic molecules and angiogenesis does not occur. Under certain conditions such as tumor formation or wound healing, the positive regulators of angiogenesis predominate and the endothelium becomes activated. Angiogenesis is initiated by vasodilatation and an increased permeability. After destabilization of the vessel wall, endothelial cells proliferate, migrate and form a tube, which is finally stabilized by pericytes and smooth muscle cells. Numerous soluble growth factors and inhibitors, cytokines and proteases as well as extracellular matrix proteins and adhesion molecules strictly control this multi-step process. The properties and interactions of angiogenic molecules such as VEGFs, FGFs, angiopoietins, PDGF, angiogenin, angiotropin, HGF, CXC chemokines with ELR motif, PECAM-1, integrins and VE-cadherin as well as angiostatic key players such as angiostatin, endostatin, thrombospondin, CXC chemokines without ELR motif, PEDF are discussed in this review with respect to their molecular impact on angiogenesis.