Phenotyping by persistent inflammation in systemic sclerosis associated interstitial lung disease: a EUSTAR database analysis

BACKGROUND

Systemic sclerosis (SSc) is a heterogeneous disease with frequently associated interstitial lung disease (SSc-ILD). We aimed to determine the prognostic potential of phenotyping patients with SSc and SSc-ILD by inflammation and to describe disease trajectories stratified by inflammation and immunosuppressive treatment.

METHODS

Patients from the European Scleroderma Trials and Research (EUSTAR) group cohort were allocated to persistent inflammatory, intermediate and non-inflammatory phenotypes if C-reactive protein (CRP) levels were ≥5 mg/L at ≥80%, at 20-80% and at <20% of visits, respectively. Cox regression models were used to analyse mortality risk and mixed effect models to describe trajectories of FVC and diffusing capacity for carbon monoxide (DLCO) %-predicted stratified by inflammation and immunosuppressive treatment.

RESULTS

2971 patients with SSc and 1171 patients with SSc-ILD had at least three CRP measurements available. Patients with SSc-ILD with a persistent inflammatory phenotype had a 6.7 times higher risk of mortality within 5 years compared with those with a persistent non-inflammatory phenotype (95% CI 3 to 15). In the inflammatory phenotype, FVC %-predicted was declining without (-1.11 (95% CI -2.14 to -0.08)/year), but stable with immunosuppressive treatment (-0.00 (95% CI -0.92 to 0.92)/year). In the non-inflammatory phenotype, patients with and without immunosuppressive treatment had a significant decline in FVC %-predicted, which was more pronounced in those with immunosuppressive treatment (-1.26 (95% CI -1.87 to -0.64) and -0.84 (95% CI -1.35 to -0.33)/year, respectively).

CONCLUSIONS

Phenotyping by persistent inflammation provides valuable prognostic information, independent of demographics, disease duration, cutaneous subtype, treatment and SSc-ILD severity. The findings from this study support early immunosuppressive treatment in patients with SSc-ILD with persistent inflammation.

[Reality of inpatient vasoactive treatment with prostacyclin derivatives in patients with acral circulation disorders due to systemic sclerosis in Germany]

Hintergrund

Das Raynaud-Phänomen und die damit häufig einhergehenden digitalen Ulzerationen stellen für Patienten mit systemischer Sklerose (Sklerodermie [SSc]) ein frühes und sehr belastendes Symptom mit bedeutenden Einschränkungen der Arbeitsfähigkeit und Lebensqualität dar. Der Einsatz vasoaktiver Medikamente (insbesondere intravenöser Prostazyklinderivate) soll helfen, das Risiko hypoxischer Gewebeschäden bis hin zum Verlust der Finger zu reduzieren.

Methoden

Um Aufschluss über die aktuelle Versorgung von Patienten mit Prostazyklinderivaten im klinischen Alltag in Deutschland zu erhalten, führten wir eine Umfrage unter den im Deutschen Netzwerk für systemische Sklerodermie (DNSS) zusammengeschlossenen Kliniken durch. Zusätzlich erfolgte eine separate Patientenbefragung über die Sklerodermie Selbsthilfe e. V., die sich nur auf die Symptome „Raynaud-Phänomen“ und „Digitale Ulzera“ und den Einsatz intravenöser Prostazyklinderivate bezog.

Ergebnisse

Von den befragten 433 Patienten gaben 56 % an, dass sie bereits aufgrund ihrer Erkrankung und Symptome mit Prostazyklinderivaten behandelt wurden. Insgesamt 61 % erhielten die Therapie aufgrund starker Raynaud-Symptomatik und 39 % aufgrund digitaler Ulzerationen. Die meisten Befragten erfuhren durch die Therapie nicht nur eine Verbesserung des Raynaud-Phänomens und der digitalen Ulzera, sondern auch eine wesentliche Verbesserung von Einschränkungen im Alltag. Sie gaben zudem an, wesentlich weniger fremde Hilfe in Anspruch genommen sowie wesentlich weniger Fehlzeiten bei der Arbeit gehabt zu haben.

Schlussfolgerung

Die Patienten empfanden durchweg einen positiven Effekt der Therapie mit Prostazyklinderivaten auf das Raynaud-Phänomen, ihre digitalen Ulzerationen, Schmerzen und Alltagseinschränkung und fühlten sich durch die stationäre Therapie gut und sicher betreut. Diese positiven Effekte in der Patientenwahrnehmung sind eine eindrückliche Stütze und bestätigen nachdrücklich die auf europäischer und internationaler Ebene erarbeiteten Therapieempfehlungen.

Zusatzmaterial online

Die Online-Version dieses Beitrags (10.1007/s00393-019-00743-9) enthält die 2 Fragebögen, die für die Befragung verwendet wurden. Beitrag und Zusatzmaterial stehen Ihnen auf www.springermedizin.de zur Verfügung. Bitte geben Sie dort den Beitragstitel in die Suche ein, das Zusatzmaterial finden Sie beim Beitrag unter „Ergänzende Inhalte“.

OP0115 EFFECT OF NINTEDANIB ON PROGRESSION OF INTERSTITIAL LUNG DISEASE (ILD) IN PATIENTS WITH AUTOIMMUNE DISEASE-RELATED ILDS: FURTHER DATA FROM THE INBUILD TRIAL

Background:

In the INBUILD trial in patients with progressive fibrosing ILDs, nintedanib reduced the rate of decline in forced vital capacity (FVC) versus placebo over 52 weeks both in the overall population and in the subgroup with autoimmune disease-related ILDs. Patients continued blinded randomised treatment until the end of the trial.

Objectives:

Assess the effects of nintedanib on the risks of death, acute exacerbation of ILD or death, and disease progression or death over the whole INBUILD trial in patients with autoimmune disease-related ILDs and a progressive phenotype.

Methods:

Patients with progressive fibrosing ILDs other than idiopathic pulmonary fibrosis (IPF) were randomised to receive nintedanib 150 mg bid or placebo. Time to i) death, ii) first acute exacerbation of ILD or death, and iii) disease progression (absolute decline in FVC ≥10% predicted) or death, over the whole trial were analysed in patients with autoimmune disease-related ILDs. Incidence rates of adverse events per 100 patient–years were calculated based on events with onset between the first trial drug intake and the last intake plus 28 days. Analyses were descriptive.

Results:

Of 663 patients, 170 (82 nintedanib, 88 placebo) had autoimmune disease-related ILDs (89 RA-ILD, 39 SSc-ILD, 19 MCTD-ILD, 23 other autoimmune ILDs including Sjogren’s disease-related ILD [n=7], interstitial pneumonia with autoimmune features [n=5] and undifferentiated CTD-ILD [n=3]). Over the whole trial, in the nintedanib and placebo groups, respectively, mean (SD) exposure to drug was 15.4 (7.4) and 16.9 (6.1) months and maximum exposure was 26.0 and 25.2 months; 62 (75.6%) and 68 (77.3%) patients in these groups, respectively, completed the planned observation time. Over the whole trial, in the nintedanib and placebo groups, respectively, 9.8% and 12.5% of patients died, 12.2% and 20.5% of patients had ≥1 acute exacerbation of ILD or died, and 40.2% and 53.4% of patients had disease progression or died (Table). Diarrhoea was the most common adverse event, with incidence rates of 139.2 and 26.3 events per 100 patient–years in the nintedanib and placebo groups, respectively. Adverse events led to treatment discontinuation in 20.7% of patients in the nintedanib group and 13.6% of patients in the placebo group.

Conclusion:

Data from the INBUILD trial suggest that nintedanib has a clinically meaningful effect on slowing the progression of ILD in patients with progressive fibrosing autoimmune disease-related ILDs, with adverse events that can be tolerated by most patients.

Table.Nintedanib (n=82)Placebo (n=88)HR (95% CI)*Death8 (9.8)11 (12.5)0.80 (0.32, 1.98)≥1 acute exacerbation of ILD or death10 (12.2)18 (20.5)0.58 (0.27, 1.27)Disease progression (absolute decline in FVC ≥10% predicted) or death33 (40.2)47 (53.4)0.72 (0.46, 1.13)

n (%) with event over the whole trial (mean [SD] exposure: 15.4 [7.4] and 16.9 [6.1] months in nintedanib and placebo groups, respectively). *Based on time to first event.

Disclosure of Interests:

Eric Matteson Grant/research support from: Pfizer, Consultant of: Boehringer Ingelheim, Gilead, TympoBio, Arena Pharmaceuticals, Speakers bureau: Simply Speaking, Clive Kelly Consultant of: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Anna-Maria Hoffmann-Vold Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Actelion, Bayer, GlaxoSmithKline, Speakers bureau: Boehringer Ingelheim, Actelion, Roche, James Seibold Shareholder of: BriaCell, Pacific Therapeutics, Consultant of: Atlantic, Blade Therapeutics, Eicos Sciences, Eiger Biopharmaceuticals, Indalo Therapeutics, Mitsubishi Tanabe Pharma, Bayer, Xenikos, Boehringer Ingelheim, Camurus, Corbus Pharmaceuticals, EMD Serono, Speakers bureau: Boehringer Ingelheim, Shikha Mittoo Grant/research support from: Pfizer, Consultant of: Novartis, Abbvie, Pfizer, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche, Paul F. Dellaripa Grant/research support from: Paul Dellaripa has received institutional grants from Genentech, Consultant of: Paul Dellaripa participated in advisory boards for Boehringer Ingelheim, Alexandra James Employee of: Employee of Boehringer Ingelheim, Rozsa Schlenker-Herceg Employee of: Employee of Boehringer Ingelheim, Susanne Stowasser Employee of: Employee of Boehringer Ingelheim, Manuel Quaresma Employee of: Employee of Boehringer Ingelheim, Kevin R. Flaherty Grant/research support from: Kevin Flaherty has received grants from Boehringer Ingelheim, Consultant of: Kevin Flaherty has acted as a consultant for Boehringer Ingelheim, Bellerophon, Blade Therapeutics, Roche/Genentech, and Veracyte

He was a member of the INBUILD trial Steering Committee

SAT0157 NINTEDANIB DOSE ADJUSTMENTS AND ADVERSE EVENTS IN PATIENTS WITH PROGRESSIVE AUTOIMMUNE DISEASE-RELATED INTERSTITIAL LUNG DISEASES IN THE INBUILD TRIAL

Background:

In the INBUILD trial in patients with progressive fibrosing ILDs, the adverse event (AE) profile of nintedanib was characterised predominantly by gastrointestinal AEs. Dose adjustments were used to manage AEs.

Objectives:

Assess AEs and dose adjustments in patients with autoimmune disease-related ILDs in the INBUILD trial.

Methods:

Patients with progressive fibrosing ILDs other than idiopathic pulmonary fibrosis were randomised to nintedanib 150 mg bid or placebo. Dose reductions to 100 mg bid and treatment interruptions were permitted to manage AEs. AEs over 52 weeks of treatment (or 28 days after last trial drug intake for patients who discontinued drug before week 52) were assessed in patients who received ≥1 dose of trial drug.

Results:

Of 663 patients in the INBUILD trial, 170 (82 nintedanib, 88 placebo) had autoimmune disease-related ILDs (89 RA-ILD, 39 SSc-ILD, 19 MCTD-ILD, 23 other autoimmune ILDs). In the nintedanib and placebo groups of patients with autoimmune disease-related ILDs, respectively, over 52 weeks, the proportions of patients with ≥1 dose reduction were 28.0% and 3.4%, with ≥1 treatment interruption were 31.7% and 10.2%, and with ≥1 dose reduction and/or treatment interruption were 40.2% and 12.5% (Table). Dose intensity (amount of drug administered divided by amount that would have been received had 150 mg bid been administered over 52 weeks or until permanent treatment discontinuation) was >90% in 80.5% of patients in the nintedanib group and 95.5% in the placebo group. AEs led to permanent treatment discontinuation in 17.1% and 10.2% of patients treated with nintedanib and placebo, respectively. Diarrhoea was the most common AE, reported in 63.4% and 27.3% of patients in the nintedanib and placebo groups, respectively. Diarrhoea AEs led to dose reduction, treatment interruption and permanent treatment discontinuation in 7.3%, 9.8% and 4.9% of patients in the nintedanib group, compared with 0%, 1.1% and 1.1% of patients in the placebo group, respectively. Of the nintedanib-treated patients who experienced ≥1 diarrhoea AE, 80.8% experienced 1 or 2 events and 76.9% experienced events that were mild at worst (Common Terminology Criteria for Adverse Events [CTCAE] grade 1).

Conclusion:

In the INBUILD trial, management of AEs via dose adjustments enabled most patients with autoimmune disease-related ILDs to remain on treatment for 52 weeks. Diarrhoea was the AE that most commonly led to dose adjustment.

TableNintedanib(n=82)Placebo (n=88)Patients with ≥1 dose reduction or treatment interruption33 (40.2)11 (12.5)Patients with ≥1 dose reduction23 (28.0)3 (3.4)Total number of dose reductions253Patients with ≥1 dose re-escalation after dose reduction5 (6.1)2 (2.3)Patients with ≥1 treatment interruption26 (31.7)9 (10.2)Total number of treatment interruptions3211Total duration of treatment interruptions, days, mean (SD)20.1 (15.1)19.3 (20.7)

Disclosure of Interests:

Elizabeth Volkmann Grant/research support from: Forbius, Corbus Pharmaceuticals, Consultant of: Boehringer Ingelheim, Forbius, Speakers bureau: Boehringer Ingelheim, Ivan Castellví Consultant of: Boehringer Ingelheim, Actelion, Kern Pharma, Speakers bureau: Boehringer Ingelheim, Actelion, Bristol-Myers Squibb, Roche, Sindhu Johnson Grant/research support from: Boehringer Ingelheim, Corbus Pharmaceuticals, GlaxoSmithKline, Roche, Merck, Bayer, Consultant of: Boehringer Ingelheim, Ikaria, Eric Matteson Grant/research support from: Pfizer, Consultant of: Boehringer Ingelheim, Gilead, TympoBio, Arena Pharmaceuticals, Speakers bureau: Simply Speaking, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, James Seibold Shareholder of: BriaCell, Pacific Therapeutics, Consultant of: Atlantic, Blade Therapeutics, Eicos Sciences, Eiger Biopharmaceuticals, Indalo Therapeutics, Mitsubishi Tanabe Pharma, Bayer, Xenikos, Boehringer Ingelheim, Camurus, Corbus Pharmaceuticals, EMD Serono, Speakers bureau: Boehringer Ingelheim, Ulrich Costabel Consultant of: Boehringer Ingelheim, Roche, Fibrogen, Global Blood Therapeutics, Speakers bureau: Boehringer Ingelheim, Roche, AstraZeneca, Alexandra James Employee of: Employee of Boehringer Ingelheim, Carl Coeck Employee of: Employee of Boehringer Ingelheim, Manuel Quaresma Employee of: Employee of Boehringer Ingelheim, Vincent Cottin Grant/research support from: Boehringer Ingelheim, Roche, Consultant of: Boehringer Ingelheim, Roche, Actelion, Bayer, Gilead Sciences, Novartis, Promedior, Celgene, Galapagos, Galecto. He was a member of the INBUILD trial Steering Committee., Speakers bureau: Actelion, Boehringer Ingelheim, Novartis, Roche, Sanofi

SAT0342 INNATE LYMPHOID CELLS ARE PREDICTORS OF DISEASE PROGRESSION IN SYSTEMIC SCLEROSIS: A 3-YEARS FOLLOW-UP STUDY

Background:

Activation of the immune system is a characteristic feature of SSc. Numerous studies have suggested that type 2 are key drivers of progressive fibrosis. Recently, innate lymphoid cells (ILC) are emerging as an important cellular source of type 2 cytokines triggering fibrotic tissue remodeling independently of the adaptive immune system. Increased levels of ILC2 were found in patients with SSc. However, the contributive role of ILC2 in pathogenesis of SSc is not completely understood.

Objectives:

We aim in our 3 years observational study to evaluate the predictive role of ILC2 in SSc patients.

Methods:

We conducted an observational retrospective study on 52 patients with SSc fulfilling the 2013 ACR/EULAR classification criteria. Yearly clinical, laboratory and investigational data according to EUSTAR recommendations were collected. Blood samples collected between 15.09.2014 and 15.01.2015 were analyzed by flow cytometry and ILC2 counts were measured. The predictive value of ILC2 during a 3-year follow-up was analyzed using SPSS 21.0.

Results:

52 patients were included in the study, 78% female, 63% limited cutaneous SSc with a mean follow-up time of 2.85 ± 1.28 years. At baseline we have shown that circulating ILC2s are significantly increased compared to gender and age-matched healthy controls. Increased numbers of ILC2s significantly correlated with worsening of mRSS calculated by five point increase in mRSS or 25% increase from baseline (p < 0.001; 95% CI 1.39 – 3.26). ILC2 counts also correlated with 5% decrease of diffusion capacity of carbon monoxide (DLCO) during the follow-up time (p < 0.0001; 95% CI 1.83 – 3.49). Worsening of forced vital capacity (FVC) assessed as 5% decrease over 2 years was also significantly correlated with an increased number of ILC2s (p < 0.0001; 95% CI 1.27 – 3.04). In contrast, we did not find any correlation regarding increase in pulmonary arterial pressure assessed by echocardiography. Although new appearance of digital ulcers could not be predicted by ILC2 counts, increased numbers of ILC2s were correlated with digital ulcers at follow-up.

Conclusion:

Here, we provide first evidence for a role of ILC2s as potential prognostic marker of disease progression in SSc.

Disclosure of Interests:

Alina Soare: None declared, Stefanie Weber: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

OP0142 FIBROBLAST GROWTH FACTOR RECEPTOR 3 REGULATES THE ACTIVITY OF PROFIBROTIC CYTOKINE AND GROWTH FACTOR PATHWAYS TO DRIVE FIBROBLAST ACTIVATION AND TISSUE FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Fibroblast growth factor receptor 3 (FGFR3) is a member of the family of different fibroblast growth factor receptors with several ligands called fibroblast growth factors (FGFs) in humans. Each FGFR has different isoforms resulting from natural alternative splice variants. Upon binding FGF ligands, fibroblast growth factor receptors (FGFRs) trigger various intracellular signaling pathways to regulate important biological processes. Systematic evaluation of FGF/FGFR signaling in the context of SSc has not been performed so far.

Objectives:

The aim of this study was to characterize FGFR3/FGF9 signaling in the context of fibroblast activation and to evaluate FGFR3 as a potential molecular target for antifibrotic treatment in SSc.

Methods:

Differential expression profiling of dermal cells from SSc patients and healthy volunteers were performed employing GEArray cDNA microarray. Real-time PCR, Western Blot, immunohistochemistry and immunofluorescence were done in skin tissues and fibroblasts from SSc patients. Selective inhibitors in conjunction with genetic knockdown and knockout strategies were used to target FGFR3 signalingin vitroand in mouse models of SSc: skin fibrosis induced by bleomycin and by overexpression of a constitutively active transforming growth factor receptor 1 (TBR) and tight skin-1 (TSK) mice. Affymetrix gene arrays in dermal fibroblasts from mice with constitutive FGFR3 signaling and mice lacking FGFR3.

Results:

Expression of FGFR3, specifically the isoform FGFR3IIIb and its ligand FGF9, was significantly upregulated in the dermis and dermal fibroblasts of SSc patients as compared to healthy volunteers. Furthermore, an increase of FGFR3 IIIb/FGF9 expression comparable to that in SSc fibroblasts could also be obtained by stimulating normal healthy dermal fibroblasts with transforming growth factor (TGFβ)in vitroand in mice constitutively overexpressing active TGFβ receptor type I.

Transcriptome profiling,in silicoanalysis and functional experiments revealed that FGFR3 synergistigically induces multiple profibrotic pathways including Endothelin-, Interleukin-4- and CTGF-signaling in a CREB-dependent manner. FGFR3 exerts profibrotic effects by modulating phosphorylation of CREB by ERK-, AKT-, CAMK2- and p38-kinases. Activation of FGFR3 in healthy or SSc dermal fibroblasts by stimulation with recombinant FGF9 was sufficient to induce resting fibroblast-to-myofibroblast differentiation along with increased collagen secretion and alpha-SMA production.

Genetic knockout of Fgfr3 abrogates myofibroblast differentiationin vitroand ameliorates skin fibrosis in TSK and TBR mice and in bleomycin-induced fibrosis. Further confirming the translational potential of these findings in the preclinical models of SSc, we demonstrate that pharmacological inactivation of FGFR3 by PD173074 could induce the regression of experimental fibrosis invitroand in bleomycin-challenged, TSK and TBR mice.

Conclusion:

Our findings characterize FGFR3 as an upstream regulator of a network of profibrotic mediators in SSc and thus, we could demonstrate successfully that the targeted inhibition of FGFR3 could inhibit multiple signaling pathwaysin vitroand ameliorated fibrosis in different preclinical models of SSc. These findings may have direct translational implications as FGFR3 inhibitors are currently in development.

Disclosure of Interests:

Debomita Chakraborty: None declared, Honglin Zhu: None declared, Astrid Juengel: None declared, Lena Summa: None declared, Yi-Nan Li: None declared, Christina Bergmann: None declared, Alexandru-Emil Matei: None declared, Thuong Trinh-Minh: None declared, Chih-Wei Chen: None declared, Clara Dees: None declared, Andreas Ramming: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

SAT0291 THE ROLE OF X-LINKED INHIBITOR OF APOPTOSIS PROTEIN (XIAP) IN SYSTEMIC SCLEROSIS

Background:

Pathologic activation of fibroblasts is a central feature of fibrotic tissue disease in Systemic Sclerosis (SSc). Although individual key signaling pathways of fibroblast activation such as transforming growth factor β (TGFβ) and WNT/β-catenin signaling have been identified, the consequences of the concomitant upregulation of these pathways and their crosstalk are incompletely characterized. Given the high medical need, the identification of mutual activation and amplification loops of profibrotic signals is essential to identify novel candidates for antifibrotic therapies. XIAP (X-linked inhibitor of apoptosis protein) is a ubiquitously expressed member of the IAP protein family which are implicated in the regulation of various cellular functions and tissue turnover. XIAP was recently described to be implicated in WNT/β-catenin signaling and TGFβ signaling.

Objectives:

The aim of this study is to characterize the role of XIAP in fibrotic disease.

Methods:

XIAP-expression was analyzed by qPCR, IF and Western blot. XIAP was targeted pharmacologically and with siRNA. The activation of WNT/β-catenin signaling was assessed by analyses of WNT target genes, by TOPflash/FOPflash luciferase reporter assay and in reporter mice.In vivo,XIAP inhibition was analysed in two different models of fibrosis.

Results:

The expression of XIAP is increased in the skin of SSc patients compared to matched healthy individuals with a particular prominent expression in fibroblasts. The overexpression of XIAP is more pronounced in SSc patients with diffuse and active skin fibrosis compared to SSc patients with limited and inactive disease. The overexpression of XIAP is also reflected in several experimental fibrosis models: the model of sclerodermatous graft versus host disease, the model of bleomycin induced skin fibrosis and Topoisomerase I induced fibrosis (TopoI) mice. TGFβ induces the expression of XIAP in vitro and in vivo and treatment with the TGFβ1 receptor antagonist SD208 reverses the TGFβ induced expression of XIAP. Inhibition of XIAP with embelin or siRNA reduces the TGFβ induced activation of fibroblasts with reduced collagen release and reduced expression of myofibroblast markers. In addition, XIAP inhibition reverted the activated fibroblast phenotype in SSc fibroblasts with reduced expression of stress fibers and αSMA. The antifibrotic effects of XIAP inhibition occurred in non-toxic doses as demonstrated by MTT and by TUNEL staining. In vivo, inhibition of XIAP reduced skin fibrosis in the models of bleomycin induced skin fibrosis and in TopoI-induced skin and lung fibrosis as demonstrated by analysis of dermal thickening, dermal hydroxyproline content and by analysis of myofibroblast differentiation. Mechanistically, XIAP inhibition reduced the activation of WNT/β-catenin signaling as demonstrated by TOPflash reporter assays and by the analysis of WNT target genes.

Conclusion:

XIAP is upregulated in SSc fibroblasts and murine SSc models in a TGFβ-dependent manner and promotes fibroblast activation by fostering canonical WNT signaling. Our data suggest that XIAP mediates an amplification loop between TGFβ and WNT/β-catenin signaling. Inhibition of XIAP may thus be a novel approach to target aberrant WNT/β-catenin signaling in fibrotic diseases.

Disclosure of Interests:

Christina Bergmann: None declared, Ludwig Hallenberger: None declared, Benita Merlevede: None declared, Clara Dees: None declared, Chih-Wei Chen: None declared, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

OP0141 HIGH DIMENSIONAL ANALYSIS REVEAL A NETWORK OF CERTAIN TRANSCRIPTION FACTORS THAT LINK VASCULOPATHY AND ORGAN FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Since vascular manifestations such as Raynaud’s phenomenon often precede the onset of other clinical manifestations of systemic sclerosis (SSc), the identification of pathways linking vasculopathy to organ fibrosis might thus provide important insights into early disease mechanisms and allow early targeted intervention for both fibrotic and vascular events.

Objectives:

In this study we performed high dimensional (HD) analyses to identify mediators that link vasculopathy to organ fibrosis.

Methods:

HD techniques including RNA-seq, ChIP-seq, ATAC-seq and FISH-seq have been performed to identify mediators in vessels and fibrotic lesions of human skin samples of SSc patients and healthy volunteers. In addition, murine skin and lung tissue samples were analyzed by multi-channel immunofluorescence (IF) and confocal laser scanning microscopy. Microvascular endothelial cells, smooth muscle cells and fibroblasts have been further processed to address their functional attributes with regard to their proliferative, migratory and chemotactic capacity. In vivo models and ex vivomouse fetal metatarsal assays were performed to study fibrotic and angiogenic processes.

Results:

Bioinformatic HD analyses revealed the ETS transcription factor PU.1 as molecular checkpoint of a network of factors that drive matrix production and fibrotic imprinting in SSc. Within this network ATF3 was significantly upregulated in fibroblasts of skin biopsies of SSc patients and of various organs of fibrosis models. ATF3 deficiency ameliorated fibrosis in various mouse models. Notably, ATF3 was significantly upregulated in vascular cells of fibrotic tissues of SSc patients. Multi-channel IF and confocal laser scanning microscopy of skin and lung biopsies of SSc patients revealed an increased expression of ATF3 especially in microvascular endothelial cells and smooth muscle cells. ATF3 overexpression in smooth muscle cells led to an extensively enhanced proliferation and increased migratory capacity whereas endothelial cells showed a SSc-like phenotype with reduced proliferation and migration. After ATF3 overexpression, tube formation capacity was completely altered as assessed by cumulative tube length, tube numbers and capillary sprouting. To investigate vessel outgrowth from a different perspective, we used theex vivofetal mouse metatarsal assay. ATF3 knockout mice showed a completely altered angiogenic response as assessed by tube length, number of branches and number junctions compared to wildtype controls.

Conclusion:

We identified PU.1 and ATF3 as key factors in disturbed vasculature and endogenous activated fibroblasts suggesting this axis as a potential therapeutic target intervening both fibrotic and vascular manifestations.

Disclosure of Interests:

Charles Gwellem Anchang: None declared, Bettina Matalobos Lawaree: None declared, Stefanie Weber: None declared, Simon Rauber: None declared, Thomas Wohlfahrt: None declared, Markus Luber: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

SAT0354 TYPE 3 INNATE LYMPHOID CELLS ARE KEY DRIVERS OF PSORIATIC ARTHRITIS

Background:

Psoriasis (PsO) and psoriatic arthritis (PsA) are two types of chronic inflammatory diseases that share a similar cytokines profile. About 30% of PsO patients also develop a joint involvement, but the underlying mechanism is still unclear. Innate lymphoid cells (ILC) and specifically the type 3 ILCs (ILC3s) have raised increasing interest as possible player in the pathogenesis of both diseases, as they produce the pathological key cytokine IL-17A.

Objectives:

We addressed the contribution of ILC3s to the pathogenesis of PsO and PsA in patients as well as murinein vivomodels.

Methods:

130 patients satisfying the Classification Criteria for Psoriatic Arthritis (CASPAR), 40 patients with PsO and 35 healthy volunteers were enrolled in the study. Information regarding clinical features, laboratory parameters were collected and psoriasis area severity index (PASI), disease activity score 28 (DAS28), disease activity in psoriatic arthritis (DAPSA), minimal disease activity score (MDA) were calculated. Magnetic resonance imaging (MRI) and high-resolution peripheral CT (HR-pQCT) were taken and PsA MRI score (PsAMRIS) was assessed. Flow cytometric analysis was performed and IFNγ-producing ILC1s, IL-4/IL-5-producing ILC2s and IL-17/IL-22-producing ILC3s were identified among ILCs. Multivariate linear regression and Receiver-Operating Characteristic (ROC) Curve analysis was performed using the IBM SPSS Statistics software. Different in vivo models were used to assess functional implications of ILCs at different time points of the disease. Joint inflammation was assessed through MRI and H&E staining of ankle areas. Peripheral blood was obtained from mice of each group and flow cytometry analysis was performed. High dimensional analyses including RNA-seq was performed to identify phenotypic characteristics of ILCs implemented into the pathogenesis of the disease.

Results:

Total number of circulating ILCs were increased in PsA patients compared to PsO and healthy controls (p<0,001). Linear regression analyses of the relationship between disease activity and circulating ILCs counts showed strongest correlation between ILC3s counts and DAPSA score. ILC3s counts also correlated with imaging signs of inflammation such as enthesitis, synovitis, erosions and/or ostoeproliferation as assessed by MRI and HR-pQCT. Musculoskeletal inflammation in mice was predominantly associated with p19 expression and IL-23R-signaling as assessed by RNA-seq. These effects were also accompanied by a strong upregulation of IL-17-producing lymphocytes within the inflamed joint niche with a dominant presence of ILC3s. Multi-channel immunofluorescence and confocal laser scanning microscopy revealed not only upregulation of ILC3 induced IL-17 production within the synovial membrane but also in peri-articular areas of the inflamed joints.

Conclusion:

ILC3s not only correlate with various facets of PsA manifestations but also functionally contribute to synovitis and enthesitis suggesting them as interesting target for upcoming treatment strategies in the near future.

Disclosure of Interests:

Maria Gabriella Raimondo Grant/research support from: Celgene, Partner Fellowship, Simon Rauber: None declared, Markus Luber: None declared, Aleix Rius Rigau: None declared, Stefanie Weber: None declared, Charles Gwellem Anchang: None declared, Rahul Agarwal: None declared, Alina Soare: None declared, Michael Sticherling Grant/research support from: Novartis, Consultant of: Advisory boards Abbvie, Celgene, Janssen Cilag, Lilly, Pfizer, MSD, Novartis, Amgen, Leo, Sanofi, UCB, Speakers bureau: Abbvie, Celgene, Janssen Cilag, Leo, MSD, Novartis, Pfizer, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

SAT0284 EPIGENETIC DEREGULATION OF AUTOPHAGY PROMOTES FIBROSIS IN 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. Several stimuli present in fibrosis such as pro-fibrotic cytokines are known to activate autophagy.

Objectives:

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

Methods:

Activation of autophagy in SSc skin and matched tissue samples from healthy individuals was assessed by immunofluorescence staining for ATG7, BECLIN1 and P62. We generatedAtg7fl/flxCol1a2;CreER mice to selectively disable autophagy in fibroblasts. The role of the autophagy was investigated in the model of bleomycin- and TβRIact-induced dermal and pulmonary fibrosis. Overexpression of Myst1 was achieved by adenovirus encoding forMyst1. Collagen release and protein expression were measure by Western blot. Target genes were analyzed by RT-PCR. Co-immunoprecipitation and reporter assay were performed to study physical and functional interactions between MYST1 and SMAD3. To monitor the autophagic fluxin vitroandin vivowe generated adenoviral vectors encoding for tandem fluorescent-tagged LC3 (mRFP-EGFP-LC3).

Results:

Transforming growth factor-β (TGFβ) activates autophagy by an epigenetic mechanism to amplify its profibrotic effects. TGFβ induces autophagy in fibrotic diseases by SMAD3-dependent downregulation of the H4K16 histone acetyltransferase MYST1, which regulates the expression of core components of the autophagy machinery such as ATG7 and BECLIN1. Activation of autophagy in fibroblasts promotes collagen release and is both, sufficient and required, to induce tissue fibrosis. Forced expression of MYST1 abrogates the stimulatory effects of TGFβ on autophagy and re-establishes the epigenetic control of autophagy in fibrotic conditions. Interference with the aberrant activation of autophagy inhibits TGFβ-induced fibroblast activation and ameliorates experimental dermal and pulmonary fibrosis. These findings link uncontrolled TGFβ signaling to aberrant autophagy, deregulated epigenetics in fibrotic diseases and may open new avenues for therapeutic intervention in fibrotic diseases.

Conclusion:

We demonstrate that the epigenetic control of autophagy is disturbed by a TGFβ-dependent downregulation of the H4K16 histone acetyltransferase MYST1. The increased activation of autophagy induces fibroblast-to-myofibroblast transition and promotes fibrotic tissue remodeling. Re-expression of MYST1 prevents aberrant autophagy, limits the profibrotic effects of TGFβ and ameliorates experimental fibrosis. Restoration of the epigenetic control of autophagy might thus be a novel approach to ameliorate fibrotic tissue remodeling.

References:

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

[2]Distler, J.H., et al. Review: Frontiers of Antifibrotic Therapy in Systemic Sclerosis. Arthritis & rheumatology (Hoboken, N.J.) 69, 257-267 (2017).

[3]Gyorfi, A.H., Matei, A.E. & Distler, J.H.W. Targeting TGF-beta signaling for the treatment of fibrosis. Matrix biology: journal of the International Society for Matrix Biology 68-69, 8-27 (2018).

[4]Wang, C.W. & Klionsky, D.J. The molecular mechanism of autophagy. Mol Med 9, 65-76 (2003).

[5]Hernandez-Gea, V., 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, Neng Yu Lin: None declared, Yi-Nan Li: None declared, Andrea-Hermina Györfi: None declared, Christina Bergmann: None declared, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

SAT0302 INNATE LYMPHOID CELLS INDUCE A FIBROTIC PHENOTYPE OF FIBROBLASTS

Background:

Fibrotic diseases are characterized by excessive extracellular matrix production as a result of immune-mediated permanent fibroblast activation. Innate lymphoid cells type II (ILC2) are an only recently discovered cell type involved in barrier integrity and tissue homeostasis. There is upcoming evidence that ILC2s play a central role in mediating fibrotic diseases.

Objectives:

The aim of the study was to further elucidate the role of ILC2s in fibrotic tissue remodeling and fibroblast activation.

Methods:

Skin biopsies of patients with systemic sclerosis (SSc) or sclerodermatous chronic graft versus host disease (scGvHD) as well as lung biopsies of patients with idiopathic pulmonary fibrosis (IPF) were analyzed by immunofluorescence (IF) staining. Single cell RNA-sequencing (scRNA-seq) was performed on ILCs from fibrotic skin and lung of bleomycin-challenged mice. Further characterization of ILC2 phenotypes in fibrosis models was done by flow cytometry.In vitroculture of fibroblasts and ILC2s was used to study cellular interaction and fibrotic activation. Quantitative realtime-PCR, western blot, IF staining and ELISA were used as readouts.

Results:

Two different subtypes of ILC2s were found in skin of SSc and scGvHD patients as well as in lungs of IPF patients with one subpopulation being particularly increased in fibrotic tissue. Single cell RNA-sequencing confirmed the existence of two major populations of ILC2s in experimental fibrosis. One subtype showed features of immature ILC2 progenitors and was actively recruited from the bone marrow during fibrotic tissue remodeling. The other ILC2 subset was highly activated and expressed pro-fibrotic cytokines. These profibrotic ILC2s directly interacted with fibroblasts in a cell contact dependent manner. Semaphorin 4A (SEMA4A) expressed by ILC2s bound to Plexin D1 (PLXND1) on fibroblasts. This interaction resulted into fibrotic imprinting with high expression levels of the transcription factor PU.1 which was recently described as central regulator of the pro-fibrotic gene expression program (Wohlfahrt et al. 2019). Signaling through Jagged 1 (JAG1) and Notch receptor 2 (NOTCH2) was identified as a second mechanism of interaction between fibroblasts and ILC2s. JAG1 expressed by fibroblasts activated NOTCH2 signaling in ILC2s which emphazised the secretion of pro-fibrotic cytokines.

Conclusion:

We identified a bidirectional interaction between ILCs and fibroblasts incorporating a vicious circle of fibrotic tissue remodelling. As ILCs are still not accessible as therapeutic targets these results might contribute to the development of new strategies for anti-fibrotic therapies.

References:

[1]Wohlfahrt, Thomas, Simon Rauber, Steffen Uebe, Markus Luber, Alina Soare, Arif Ekici, Stefanie Weber, Alexandru-Emil Matei, Chih-Wei Chen, Christiane Maier, Emmanuel Karouzakis, Hans P. Kiener, Elena Pachera, Clara Dees, Christian Beyer, Christoph Daniel, Kolja Gelse, Andreas E. Kremer, Elisabeth Naschberger, Michael Stürzl, Falk Butter, Michael Sticherling, Susetta Finotto, Alexander Kreuter, Mark H. Kaplan, Astrid Jüngel, Steffen Gay, Stephen L. Nutt, David W. Boykin, Gregory M. K. Poon, Oliver Distler, Georg Schett, Jörg H. W. Distler, and Andreas Ramming. 2019. ‘PU.1 controls fibroblast polarization and tissue fibrosis’,Nature, 566: 344-49.

Disclosure of Interests:

Stefanie Weber: None declared, Charles Gwellem Anchang: None declared, Simon Rauber: None declared, Markus Luber: None declared, Maria Gabriella Raimondo Grant/research support from: Celgene, Partner Fellowship, Yuko Ariza Employee of: Ono Pharmaceutical Co., Ltd., Aleix Rius Rigau: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

OP0135 INHIBITION OF HSP90 REDUCES PROGRESSION OF DERMAL FIBROSIS AND INDUCES REGRESSION OF ESTABLISHED EXPERIMENTAL DERMAL FIBROSIS INDUCED BY BLEOMYCIN

Background:

Our previous study demonstrated that Heat shock protein 90 (Hsp90) is overexpressed in the skin of patients with systemic sclerosis (SSc), in cultured SSc fibroblasts and preclinical models of SSc. HSP90 is a new regulator of canonical TGF-β signalling and its inhibition prevents the stimulatory effects of TGF-β on collagen synthesis and dermal fibrosis in three preclinical models of SSc.

Objectives:

Herein, we aimed to evaluate the efficacy of Hsp90 inhibitor (17-DMAG) in the treatment of established experimental dermal fibrosis induced by bleomycin.

Methods:

Design consisted of three control groups, I (NaCl-s.c./6 weeks), II (bleomycin-s.c./3w and NaCl-s.c./3w), III (bleomycin-s.c./6w), and 2 treatment groups (bleomycin-s.c./6w). During the last 3 weeks, one group was treated with 17-DMAG 0.5mg/kg-i.p. every third day, whereas one group (with nintedanib 50mg/kg-p.o. twice daily) served as a comparator with already published efficacy in this setting. Total of 40 BL6 mice were examined weekly for weight, activity and fur texture. The effects of 17-DMAG were determined by assessment of dermal thickness (HE-staining), collagen content (hydroxyproline assay), myofibroblast counts (α-SMA staining) and of 23 serum inflammatory cytokines/chemokines (Mouse-Cytokine-23-plex, Bio-Rad-Laboratories).

Results:

17-DMAG decreased dermal thickening by 53±3% (p<0.001) (nintedanib by 46±2%,p<0.001), collagen content by 48±5% (p=0.004) (nintedanib by 50±4%,p=0.003), myofibroblast counts by 42±9% (p<0.001) (nintedanib by 44±7%,p<0.001), and levels of IL-1α, IL-6, IL-12(p40), CXCL1, MCP-1, MIP-1α/β, RANTES (in all: p<0.05) compared to vehicle-treated mice injected with bleomycin for 6w. Moreover, 17-DMAG also induced regression of pre-established fibrosis to below the levels of vehicle-treated mice injected with bleomycin for 3w and NaCl for 3w (dermal thickness by 14±3%, collagen content by 20±5%, myofibroblast counts by 13±9%; whereas in nintedanib by 10±3%, 21±4%, 17±7%, respectively; in all: p<0.05), and levels of IL-12(p40), CXCL1, MCP-1, MIP-1β, RANTES (in all: p<0.05). No significant weight loss, decrease in activity or changes in fur texture were observed upon 17-DMAG treatment.

Conclusion:

This is the first study on effects of Hsp90 inhibitor 17-DMAG in the treatment of established dermal fibrosis. We demonstrate that 17-DMAG effectively prevents the progression and induces regression of established bleomycin-induced dermal fibrosis, in an extent that was comparable to nintedanib in this study (which was recently FDA approved for slowing the rate of decline in lung function in adults with SSc-ILD). 17-DMAG was well tolerated without obvious clinical signs of toxicity. These data suggest that Hsp90 could be a novel potential target in the treatment of SSc dermal fibrosis.

Acknowledgments:

Supported by AZV-16-33542A, MHCR023728, SVV260373, Boehringer Ingelheim.

Disclosure of Interests:

Hana Štorkánová: None declared, Lenka Štorkánová: None declared, Sabina Oreska: None declared, Maja Špiritović: None declared, Barbora Heřmánková: None declared, Radim Bečvář Consultant of: Actelion, Roche, Karel Pavelka Consultant of: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Speakers bureau: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Jiří Vencovský: None declared, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Ladislav Šenolt: None declared, Michal Tomcik: None declared

FRI0262 INCREASED PLASMA LEVELS OF HSP90 ARE ASSOCIATED WITH MORE SEVERE LUNG AND SKIN INVOLVEMENT IN PATIENTS WITH SYSTEMIC SCLEROSIS

Background:

Our previous study demonstrated that Hsp90 is overexpressed in the skin of patients with systemic sclerosis (SSc), in cultured SSc fibroblasts and preclinical models of SSc in a TGF-β dependent manner. We showed that Hsp90 is a new regulator of canonical TGF-β signaling and its inhibition prevents the stimulatory effects of TGF-β on collagen synthesis and dermal fibrosis1.

Objectives:

The aim of this study was to evaluate plasma Hsp90 of SSc patients and characterize its potential association with skin changes and SSc-related features.

Methods:

A total of 92 patients (79 females; mean age 52.7; disease duration 6.0 years; diffuse cutaneous (dc)SSc / limited cutaneous (lc)SSc = 38/54) and 92 age- and sex- matched healthy individuals were included. Plasma Hsp90 levels were measured by ELISA (eBioscience, Vienna, Austria). Data are presented as median (IQR).

Results:

Plasma Hsp90 levels were increased in SSc patients compared to healthy controls [12.5 (9.6–17.9) vs. 9.8 (7.7–12.4) ng/mL, p=0.0001]. Hsp90 levels in all patients positively correlated with CRP (r=0.271, p=0.015). Furthermore, Hsp90 concentrations were negatively associated with functional parameters of ILD: FVC (r=-0.291, p=0.013), FEV1 (r=-0.248, p=0.036), DLCO (r=-0.290, p=0.012) and SpO2(r=-0.317, p=0.038). When adjusted for CRP, these correlations still remained significant in multivariate analysis. Higher Hsp90 concentrations were associated with presence of synovitis [17.6 (15.4 – 24.0) vs. 12.2 (9.3 – 17.3), p=0.039]. In addition, only in patients with dcSSc, Hsp90 levels positively correlated with the mRSS (r=0.437, p=0.006). In a prospective analysis of patients with progressive SSc-ILD treated with 6 (n=21 patients) or 12 (n=14 patients) monthly i.v. pulses of cyclophosphamide (CPA, 10 mg/kg) we did not observe any significant differences between the baseline sample (month 0) and blood drawn after 1, 6 and 12 months. However, baseline Hsp90 was able to predict long-term response after one year of CPA treatment (DLCOm12-m0; r=-0.494, p=0.037). Moreover, change in Hsp90 after one month of CPA treatment (Hsp90m1-m0) was able to predict the short-term inflammatory response (CRPm3-m0, r=-0.495, p=0.019; ESRm3-m0, r=-0.496, p=0.031). Concentrations of extracellular Hsp90 were not significantly affected by other main clinical parameters of SSc.

Conclusion:

We demonstrated higher plasma levels of Hsp90 in SSc patients compared to healthy controls. Concentrations of extracellular Hsp90 increase with higher inflammatory activity, with deteriorated lung functions in ILD and also with the extent and severity of the skin involvement in patients with diffuse cutaneous SSc. These data further highlight the role of Hsp90 as a significant regulator of fibroblast activation and tissue fibrosis in SSc. In addition, Hsp90 could become a predictor of treatment response.

References:

[1]Tomcik M et al., Ann Rheum Dis.2014;73(6):1215-22.

Acknowledgments:

Supported by AZV-16-33542A, MHCR 023728 and SVV – 260373.

Disclosure of Interests:

Hana Štorkánová: None declared, Sabina Oreska: None declared, Maja Špiritović: None declared, Barbora Heřmánková: None declared, Kristyna Bubova: None declared, Martin Komarc: None declared, Karel Pavelka Consultant of: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Speakers bureau: Abbvie, MSD, BMS, Egis, Roche, UCB, Medac, Pfizer, Biogen, Jiří Vencovský: None declared, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Ladislav Šenolt: None declared, Radim Bečvář Consultant of: Actelion, Roche, Michal Tomcik: None declared

SAT0287 AMPLIFICATION OF THE PRO-FIBROTIC JAK2-STAT3 SIGNALING AXIS BY TGFΒ-INDUCED EPIGENETIC SILENCING OF SOCS3

Background:

Tissue fibrosis caused by a pathological activation of fibroblasts is a major hallmark of systemic sclerosis (SSc). Epigenetic gene silencing of anti-fibrotic genes is thought to play a central role to establish the persistently activated phenotype of fibroblasts independent of external stimuli such as TGFβ, which has been identified as key-mediator of fibroblast activation.

Objectives:

The aims of the present study were to investigate whether the aberrant activation of JAK2-STAT3 signaling in fibrosis might be caused by epigenetic silencing of SOCS expression and whether re-establishment of the endogenous, SOCS-dependent control of JAK / STAT signaling may prevent aberrant fibroblast activation and ameliorate tissue fibrosis.

Methods:

The methylation status of SOCS3 in fibroblasts was evaluated by methylation-specific PCR and MeDIP assays. 5-aza-2-deoxycytidine (5-aza) and siRNA was used to inhibit DNA methyltransferases (DNMTs)in vitroandin vivo. Knockdown and overexpression experiments served to analyze the mechanism of action in cultured fibroblasts. Fibroblast-specific knockout mice were additionally used to analyze the role of SOCS3 and DNMTsin vivo.

Results:

Chronically increased levels of TGFβ reduced the expression of SOCS3 in normal fibroblasts to a level also found in SSc fibroblasts. Consistently, the expression of SOCS3 was severely downregulated in skin of SSc patients compared to healthy individuals with only minor differences between limited and diffuse cutaneous SSc. Methylation analyses demonstrated a prominent promoter hypermethylation of SOCS3 in SSc fibroblasts and in normal fibroblasts exposed to persistently high levels of TGFβ. Increased DNMT activity and a time-dependent induction of DNMT3A and DNMT1 expression upon chronic exposure to TGFβ resulted in promoter hypermethylation of SOCS3. Knockdown of SOCS3 induced an SSc-like phenotype in normal dermal fibroblasts with increased activation of JAK2-STAT3 signaling, enhanced expression of myofibroblast markers, increased collagen release, and aggravated experimental tissue fibrosis with increased activation of JAK2-STAT3 signaling. This effect was mimicked by overexpression of mutant JAK2 with mutations in the SOCS3 binding motif. Vice versa, forced overexpression of SOCS3 reduced TGFβ-mediated fibroblast activation and ameliorated the endogenous activation of SSc fibroblasts. Pharmacological inhibition or selective knockdown of DNMTs restored the normal expression of SOCS3, reduced fibroblast activation and collagen release, blocked STAT3-responsive transcription, and exerted potent antifibrotic effects in bleomycin- and TBRIact-induced dermal fibrosis. In addition, treatment with 5-aza or knockdown of either DNMT1 or DNMT3A induced regression of established fibrosis.

Conclusion:

These findings identify a novel pathway of epigenetic imprinting of fibroblasts in fibrotic disease with translational implications for the development of new targeted therapies in fibrotic diseases. We demonstrate that the chronic activation of TGFβ signaling in fibrotic diseases perturbs the epigenetic control of STAT signaling by DNMT-induced silencing of SOCS3 expression. Our data might thus strengthen the scientific rational for targeting DNA methylation in fibrotic diseases.

Disclosure of Interests:

Clara Dees: None declared, Sebastian Poetter: None declared, Yun Zhang: None declared, Christina Bergmann: None declared, xiang zhou: None declared, Markus Luber: None declared, Emmanuel Karouzakis: None declared, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

AB0172 PGC-1Α REGULATES AUTOPHAGY TO PROMOTE FIBROBLAST ACTIVATION AND TISSUE FIBROSIS

Background:

Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) is the best studied member of the family of coactivators. PGC-1α was initially identified through its interaction with PPARγ in brown adipose tissue. Recent evidence further indicates that PGC-1α may also modulate the transcription of autophagy-related genes, which has recently been shown to be required for fibroblast-to-myofibroblast differentiation under fibrotic conditions. However, the role of PGC-1α in the pathogenesis of SSc has not been investigated.

Objectives:

The aim of the present study was to evaluate the role of the coactivator PGC-1α on autophagy and to evaluate its role in the pathologic activation of fibroblasts in SSc.

Methods:

Expression of PGC-1α was analyzed by RT-PCR, Western blot and immunofluorescence. Modulation of autophagy was analyzed by reporter studies by expression of autophagy related genes. The effects of PGC-1α knockdown on collagen production and myofibroblast differentiation were analyzed in cultured human fibroblasts and in two mouse models with fibroblast-specific knockout of PGC-1α.

Results:

PGC-1α overexpression was detected by immunohistochemistry in skin sections of SSc patients and in experimental fibrotic murine skin, particularly in fibroblasts. Knockdown of PGC-1α inhibited the stimulatory effects of TGFβ on fibroblast activation with impaired induction of collagen as compared to control fibroblasts. Fibroblasts specific knockout of PGC-1α ameliorates experimental fibrosis in bleomycin-induced and adTBR-induced murine dermal fibrosis with decreased dermal thickness, hydroxyproline and myofibroblast counts compared to wild-type fibrotic mice. Incubation of dermal fibroblasts with TGFβ activated autophagy in control fibroblasts with increased expression of the autophagy-related genes ATG7 and BECLIN-1, enhanced conversion of LC3 I to LC3 II and decreased ratios of ILC3 I EGFP to LC3 II RFP in LC3 reporter assays. The expression levels of ATG7, BECLIN-1 and ILC3 II of TGFβ-stimulated PGC-1α knockout fibroblasts decreased compare to TGFβ stimulated wild-type fibroblasts. The ratio of ILC3 I EGFP to LC3 II RFP of TGFβ-stimulated PGC-1α knockout fibroblasts in reporter assays were comparable to unstimulated fibroblasts.

Conclusion:

PGC-1α is upregulated in SSc and promotes autophagy to foster TGFβ-induced fibroblast activation. Targeting of PGC-1α prevents aberrant autophagy, inhibits fibroblast activation and tissue fibrosis.

References:

[1]Finck BN, Kelly DP. PGC-1 coactivators: inducible regulators of energy metabolism in health and disease. The Journal of clinical investigation. 2006 Mar; 116(3):615-622

[2]Lindholm D, Eriksson O, Makela J, Belluardo N, Korhonen L. PGC-1alpha: a master gene that is hard to master. Cellular and molecular life sciences: CMLS. 2012 Aug; 69(15):2465-2468.

[3]Li SY, Susztak K. The Role of Peroxisome Proliferator-Activated Receptor gamma Coactivator 1alpha (PGC-1alpha) in Kidney Disease. Semin Nephrol. 2018 Mar; 38(2):121-126.

[4]Vainshtein A, Tryon LD, Pauly M, Hood DA. Role of PGC-1alpha during acute exercise-induced autophagy and mitophagy in skeletal muscle. American journal of physiology Cell physiology. 2015 May 1; 308(9):C710-719.

[5]Zehender A LN, Stefanica A, Chen CW, Soare A, Wohlfahrt T, Rauber S, Bergmann C, Ramming A, Distler O, Schett G, Distler J. TGFβ Promotes Fibrosis By MYST1-Dependent Epigenetic Regulation of Autophagy [abstract]. Arthritis Rheumatol 2017; 69 (suppl 10).

Disclosure of Interests:

Yun Zhang: None declared, Katja Dreißigacker: None declared, Diana Distler: None declared, Andrea-Hermina Györfi: None declared, Christina Bergmann: None declared, xiang zhou: None declared, Lichong Shen: None declared, Ingo Ludolph: None declared, Raymund Horch: None declared, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

AB1346-HPR REAL-WORLD EFFECTIVENESS AND PERCEIVED USEFULNESS OF SYMPTOM CHECKERS IN RHEUMATOLOGY: INTERIM REPORT FROM THE PROSPECTIVE MULTICENTER BETTER STUDY

Background:

Symptom checkers (SC) promise to reduce diagnostic delay, misdiagnosis and effectively guide patients through healthcare systems. They are increasingly used, however little evidence exists about their real-life effectiveness.

Objectives:

The aim of this study was to evaluate the diagnostic accuracy, usage time, usability and perceived usefulness of two promising SC, ADA (www.ada.com) and Rheport (www.rheport.de). Furthermore, symptom duration and previous symptom checking was recorded.

Methods:

Cross-sectional interim clinical data from the first of three recruiting centers from the prospective, real-world, multicenter bETTeR-study (DKRS DRKS00017642) was used. Patients newly presenting to a secondary rheumatology outpatient clinic between September and December 2019 completed the ADA and Rheport SC. The time and answers were recorded and compared to the patient’s actual diagnosis. ADA provides up to 5 disease suggestions, Rheport calculates a risk score for rheumatic musculoskeletal diseases (RMDs) (≥1=RMD). For both SC the sensitivity, specificity was calculated regarding RMDs. Furthermore, patients completed a survey evaluating the SC usability using the system usability scale (SUS), perceived usefulness, previous symptom checking and symptom duration.

Results:

Of the 129 consecutive patients approached, 97 agreed to participate. 38% (37/97) of the presenting patients presented with an RMD (Figure 1). Mean symptom duration was 146 weeks and a mean number of 10 physician contacts occurred previously, to evaluate current symptoms. 56% (54/96) had previously checked their symptoms on the internet using search engines, spending a mean of 6 hours. Rheport showed a sensitivity of 49% (18/37) and specificity of 58% (35/60) concerning RMDs. ADA’s top 1 and top 5 disease suggestions concerning RMD showed a sensitivity of 43% (16/37) and 54% (20/37) and a specificity of 58% (35/60) and 52% (31/60), respectively. ADA listed the correct diagnosis of the patients with RMDs first or within the first 5 disease suggestions in 19% (7/37) and 30% (11/37), respectively. The average perceived usefulness for checking symptoms using ADA, internet search engines and Rheport was 3.0, 3.5 and 3.1 on a visual analog scale from 1-5 (5=very useful). 61% (59/96) and 64% (61/96) would recommend using ADA and Rheport, respectively. The mean SUS score of ADA and Rheport was 72/100 and 73/100. The mean usage time for ADA and Rheport was 8 and 9 minutes, respectively.

Conclusion:

This is the first prospective, real-world, multicenter study evaluating the diagnostic accuracy and other features of two currently used SC in rheumatology. These interim results suggest that diagnostic accuracy is limited, however SC are well accepted among patients and in some cases, correct diagnosis can be provided out of the pocket within few minutes, saving valuable time.

Figure:

Acknowledgments:

This study was supported by an unrestricted research grant from Novartis.

Disclosure of Interests:

Johannes Knitza Grant/research support from: Research Grant: Novartis, Jacob Mohn: None declared, Christina Bergmann: None declared, Eleni Kampylafka Speakers bureau: Novartis, BMS, Janssen, Melanie Hagen: None declared, Daniela Bohr: None declared, Elizabeth Araujo Speakers bureau: Novartis, Lilly, Abbott, Matthias Englbrecht Grant/research support from: Roche Pharma, Chugai Pharma Europe, Consultant of: AbbVie, Roche Pharma, RheumaDatenRhePort GbR, Speakers bureau: AbbVie, Celgene, Chugai Pharma Europe, Lilly, Mundipharma, Novartis, Pfizer, Roche Pharma, UCB, David Simon Grant/research support from: Else Kröner-Memorial Scholarship, Novartis, Consultant of: Novartis, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Timo Meinderink: None declared, Wolfgang Vorbrüggen: None declared, Cay-Benedict von der Decken: None declared, Stefan Kleinert Shareholder of: Morphosys, Grant/research support from: Novartis, Consultant of: Novartis, Speakers bureau: Abbvie, Novartis, Celgene, Roche, Chugai, Janssen, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Peter Bartz-Bazzanella: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Axel Hueber Grant/research support from: Novartis, Lilly, Pfizer, Consultant of: Abbvie, BMS, Celgene, Gilead, GSK, Lilly, Novartis, Speakers bureau: GSK, Lilly, Novartis, Martin Welcker Grant/research support from: Abbvie, Novartis, UCB, Hexal, BMS, Lilly, Roche, Celgene, Sanofi, Consultant of: Abbvie, Actelion, Aescu, Amgen, Celgene, Hexal, Janssen, Medac, Novartis, Pfizer, Sanofi, UCB, Speakers bureau: Abbvie, Aescu, Amgen, Biogen, Berlin Chemie, Celgene, GSK, Hexal, Mylan, Novartis, Pfizer, UCB

OP0195 VASCULARIZED THREE-DIMENSIONAL MODELS OF HUMAN SKIN FIBROSIS

Background:

The complex pathophysiological processes that result in fibrotic tissue remodeling in systemic sclerosis involve interplay between multiple cell types (1). Experimental models of fibrosis are essential to provide a conceptual understanding of the pathogenesis of these diseases and to test antifibrotic drugs. Current models of fibrosis have important limitations: thein vivomodels rely on species that are phylogenetically distant, whereas thein vitromodels are oversimplified cultures of a single cell type in an artificial two-dimensional environment of excessive stiffness, which imposes an unphysiological cell polarization (2).

Objectives:

Here we evaluated the potential use of vascularized, three-dimensionalin vitrohuman skin equivalents as a novel model of skin fibrosis and a platform for the evaluation of antifibrotic drugs.

Methods:

Skin equivalents were generated by seeding human endothelial cells, fibroblasts and keratinocytes on a decellularized porcine extracellular matrix with perfusable vascular structure. The skin models were cultured for one month in a system that ensured perfusion of the vascular network at physiological pressure. Fibrotic transformation induced by TGFβ and response to nintedanib as an established antifibrotic drug was evaluated by capillary Western immunoassays, qPCR, histology and immunostaining.

Results:

The vascularized human skin equivalents formed the major skin structures relevant for the pathogenesis of fibrosis: a polarized, fully matured epidermis, a stratified dermis and a perfused vessel system with small capillaries. Exposure to TGFβ led to the fibrotic transformation of the skin equivalents, with activated TGFβ downstream pathways, increased fibroblast-to-myofibroblast transition and excessive deposition of extracellular matrix. Treatment of models exposed to TGFβ with nintedanib (a drug with proven antifibrotic effects) ameliorated the fibrotic transformation of skin equivalents with reduced TGFβ signaling, fibroblast-to-myofibroblast transition and decreased extracellular matrix deposition.

Conclusion:

Here we describe a novelin vitromodel of skin fibrosis. Our data show that vascularized skin equivalents can reproduce all skin layers affected by fibrosis, that, upon exposure to TGFβ, these models recapitulate key features of fibrotic skin and that these skin models can be used as a platform for evaluation of antifibrotic drugs in a setting with high relevance for human disease.

References:

[1]Distler JHW, Gyorfi AH, Ramanujam M, Whitfield ML, Konigshoff M, Lafyatis R. Shared and distinct mechanisms of fibrosis. Nature reviews Rheumatology. 2019;15(12):705-30.

[2]Garrett SM, Baker Frost D, Feghali-Bostwick C. The mighty fibroblast and its utility in scleroderma research. Journal of scleroderma and related disorders. 2017;2(2):69-134.

Disclosure of Interests:

Alexandru-Emil Matei: None declared, Chih-Wei Chen: None declared, Lisa Kiesewetter: None declared, Andrea-Hermina Györfi: None declared, Yi-Nan Li: None declared, Thuong Trinh-Minh: None declared, Toin van Kuppevelt: None declared, Jan Hansmann: None declared, Astrid Juengel: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Florian Groeber-Becker: None declared, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim

AB0150 ADAPTOR PROTEINS ACTIVATE FIBROBLASTS IN SYSTEMIC SCLEROSIS

Background:

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by microangiopathy and fibrosis. In physiological wound healing, fibroblasts are transiently activated for tissue repair. In contrast, fibroblasts are persistently activated during fibrosis and thus resulted in progressive matrix deposition and tissue remodeling. However, the pathogenesis of the fibrotic process is not fully understood.

Objectives:

We aimed to identify molecules that play a role in chronically activated fibroblasts.

Methods:

To identify molecules specifically upregulated in human fibrotic fibroblasts, RNA-sequencing was performed. Identified adaptor proteins were further validated in skin biopsy samples of patients with limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), and evaluated correlation between expression levels and clinical parameters. Respective overexpression and siRNA knockdown were further addressedin vitro. Functional effects were assessed by qPCR, hydroxyproline, proliferation and migration assays. Mouse models of systemic sclerosis were used to functionally validate adaptor proteinsin vivo.

Results:

We identified adaptor proteins as significantly upregulated molecules in chronically active fibroblasts of skin biopsy samples from SSc patients compared to fibroblasts from healthy controls. Expression levels were correlated with the modified Rodnan skin score in the skin of SSc patients. We observed higher expression levels also in the mouse model of topoisomerase I induced skin fibrosis. This result was also observed in bleomycin induced lung fibrosis model suggesting important functions of adaptor proteins during fibrotic tissue remodeling across different organs. Fibroblast-specific knockout resulted into significantly attenuated bleomycin-induced fibrosis. Upon bleomycin challenge, hydroxyproline content was diminished in mice with genetic deficiency of adaptor proteins. In addition, COL1A1, COL1A2 and Lum mRNAs and also the number of myofibroblasts were significantly lower in knockout mice compared to wild type mice.In vitro, knockdown of adaptor proteins resulted into a significant alteration of the migratory potential of fibroblasts.

Conclusion:

Our results demonstrate that adaptor proteins play an essential role in the pathogenesis of systemic sclerosis. Understanding the molecular mechanism of adaptor proteins may lead to a novel therapeutic intervention in human SSc and related disorders.

Disclosure of Interests:

Yuko Ariza Employee of: Ono Pharmaceutical Co., Ltd., Stefanie Weber: None declared, Nils Neise: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

[Treatment of systemic sclerosis-associated interstitial lung disease]

BACKGROUND

Systemic sclerosis (SSc) is a fibrosing autoimmune disease of the connective tissue. In addition to skin fibrosis, pulmonary involvement and interstitial lung disease (ILD) in particular are the most common and severe manifestations of SSc. The disease is associated with a substantial risk of morbidity and mortality, especially in progressive ILD. In the last 5 years new treatment concepts for SSc-ILD have been investigated in numerous clinical studies.

MATERIAL AND METHODS

This review is based on a literature search in PubMed, focusing on the most relevant papers published up to the end of 2018 with the keywords "SSc" and "treatment".

RESULTS

The treatment of SSc-ILD has changed over the last few years due to the results of many clinical studies. The updated guidelines of the European League Against Rheumatism (EULAR) recommend the use of cyclophosphamide or hematopoietic stem cell transplantation. Data for a positive influence on SSc-ILD are also available for mycophenolate, tocilizumab and anabasum. Because of the pathophysiological similarities to idiopathic pulmonary fibrosis, the use of the antifibrotic agents nintedanib and pirfenidone is currently being investigated in randomized, multicenter clinical trials and could be a novel and promising therapeutic strategy.

CONCLUSION

Current drug studies may provide innovative therapeutic perspectives for SSc-ILD and could significantly improve the prognosis of affected patients in the future.

The Role of Epigenetic Modifications in Systemic Sclerosis: A Druggable Target

Systemic sclerosis (SSc) is a rare autoimmune disorder characterised by skin fibrosis that often also affects internal organs, eventually resulting in mortality. Although management of the symptoms has extended lifespan, patients still suffer from poor quality of life, hence the need for improved therapies. Development of efficacious treatments has been stymied by the unknown aetiology, although recent advancements suggest a potentially key role for epigenetics - the regulation of gene expression by noncoding RNAs and chemical modifications to DNA or DNA-associated proteins. Herein, the evidence implicating epigenetics in the pathogenesis of SSc is discussed with an emphasis on the therapeutic potential this introduces to the field - particularly the repurposing of epigenetic targeting cancer therapeutics and newly emerging miRNA-based strategies.

Stress system dysregulation in pediatric generalized anxiety disorder associated with comorbid depression

Because chronic stress is an important risk factor for anxiety states and depressive disorders, we studied hypothalamus-pituitary-adrenal (HPA) axis and sympathetic system activity via changes in cortisol and alpha amylase activity levels in pediatric generalized anxiety disorder (GAD) patients (n = 26) with comorbid depression and a healthy comparison group (n = 26). Morning plasma cortisol and diurnal profiles of salivary cortisol and salivary alpha amylase (sAA) activity were assessed, also reactivity of HPA-axis, sAA activity, and heart rate following a psychosocial stressor (Trier Social Stress Test for children). GAD patients with comorbid depression showed increased morning plasma and salivary cortisol levels, ameliorating throughout in-patient treatment, and higher sAA activity in their diurnal profile. Both HPA and sympathetic activity positively correlated with the severity of anxiety and depression. We also demonstrated a blunted HPA and sympathetic response to acute stress in patients. This pattern of neuroendocrine and sympathetic changes seems to be distinct from the one previously reported in pediatric patients with only social anxiety or depressive disorders. We propose morning plasma and saliva cortisol levels as potential physiological indicators for supporting the evaluation of symptoms' severity and treatment progress in children with GAD and comorbid depressive disorder.

Fc-gamma receptors are not involved in cartilage damage during experimental osteoarthritis

OBJECTIVE

Fc-gamma receptors (FcγRs) have been shown to play a crucial role in cartilage degradation during experimental arthritis. Although most of their effect on cartilage degradation has been attributed to their potential to promote inflammation in the presence of immunoglobulins, activating FcγRs promote cartilage degeneration in antigen-induced arthritis (AIA) independently of the level of inflammation. This prompted us to investigate, whether FcγRs may also play a role in osteoarthritis (OA)-related cartilage degradation.

METHODS

FcγR expression was measured by RT-PCR and FACS in murine cartilage tissue and chondrocytes. Experimental OA was induced by destabilisation of the medial meniscus (DMM) in WT mice and animals lacking either activating (Fc receptor γ-chain-deficient) or inhibitory (FcγRIIB-deficient) FcγRs. Cartilage damage was investigated histologically 8 weeks post-surgery by assessing proteoglycan loss and structural damage according to OARSI recommendations. Osteophyte size was measured to investigate alterations in bone turnover.

RESULTS

Expression analyses revealed significant levels for all four types of murine FcγRs in mouse chondrocytes and cartilage tissue from newborn and 8-week-old mice. Surprisingly, yet, ablation of either activating or inhibitory FcγRs did not affect cartilage damage or bone turnover during DMM-induced OA in mice.

CONCLUSION

While FcγRs appear to have a crucial role in cartilage degradation during inflammatory arthritis our data indicate that FcγRs do not influence cartilage destruction in experimental OA. This indicates that a certain threshold of inflammation is a prerequisite for FcγR-induced cartilage destruction in arthritis.

DPP4-deficient congenic rats display blunted stress, improved fear extinction and increased central NPY

BACKGROUND

Inhibitors of dipeptidyl peptidase 4 (DPP4, CD26) are used for the treatment of type 2 diabetic patients and better glucose tolerance has been confirmed in functionally DPP4-deficient congenic rats (DPP4mut), along with immunological alterations and, interestingly, a stress-resilient phenotype. All these findings are in agreement with the "moonlighting" properties of DPP4, whose proteolytic action is responsible for the inactivation of a number of regulatory peptides including, but not limited to, neuropeptide Y (NPY). Among all candidate substrates, DPP4 displays highest affinity for NPY, an endogenous anxiolytic neurotransmitter that is suggested as a candidate biomarker in post-traumatic stress disorder (PTSD) and depression.

METHODS AND RESULTS

Central and peripheral NPY levels were measured by ELISA in DPP4mut and DAwt rats revealing a significantly higher concentration of the peptide in the CSF of DPP4mut animals. This finding positively correlated with the blunted stress phenotype measured on an analgesia-meter. Additionally, when a classical fear-conditioning paradigm was investigated, short-term fear extinction was significantly potentiated in DPP4mut rats as compared to wt controls.

CONCLUSIONS

Our findings indicate a positive correlation between reduced stress-responsiveness and increased central NPY, in DPP4mut rats. Most interestingly, the behavioral phenotype extends to facilitation of fear extinction. These observations raise further interest in DPP4-modulating drugs for the potential effect on NPY metabolism, as a therapeutic tool for psychiatric conditions such as anxiety disorders and PTSD.