Plasma Hsp90 levels in patients with systemic sclerosis and relation to lung and skin involvement: a cross-sectional and longitudinal study

www.nature.com/scientificreports OPEN Plasma Hsp90 levels in patients with systemic sclerosis and relation to lung and skin involvement: a cross‑sectional and longitudinal study Hana Štorkánová1,2, Sabína Oreská1,2, Maja Špiritović1,3, Barbora Heřmánková3, Kristýna Bubová1,2, Martin Komarc4, Karel Pavelka1,2, Jiří Vencovský1,2, Jörg H. W. Distler5, Ladislav Šenolt1,2, Radim Bečvář1,2 & Michal Tomčík1,2* Our previous study demonstrated increased expression of Heat shock protein (Hsp) 90 in the skin of patients with systemic sclerosis (SSc). We aimed to evaluate plasma Hsp90 in SSc and characterize its association with SSc-related features. Ninety-two SSc patients and 92 age-/sex-matched healthy controls were recruited for the cross-sectional analysis. The longitudinal analysis comprised 30 patients with SSc associated interstitial lung disease (ILD) routinely treated with cyclophosphamide. Hsp90 was increased in SSc compared to healthy controls. Hsp90 correlated positively with C-reactive protein and negatively with pulmonary function tests: forced vital capacity and diffusing capacity for carbon monoxide (DLCO). In patients with diffuse cutaneous (dc) SSc, Hsp90 positively correlated with the modified Rodnan skin score. In SSc-ILD patients treated with cyclophosphamide, no differences in Hsp90 were found between baseline and after 1, 6, or 12 months of therapy. However, baseline Hsp90 predicts the 12-month change in DLCO. This study shows that Hsp90 plasma levels are increased in SSc patients compared to age-/sex-matched healthy controls. Elevated Hsp90 in SSc is associated with increased inflammatory activity, worse lung functions, and in dcSSc, with the extent of skin involvement. Baseline plasma Hsp90 predicts the 12-month change in DLCO in SSc-ILD patients treated with cyclophosphamide. Abbreviations Hsp90 Heat shock protein 90 SSc Systemic sclerosis lcSSc Limited cutaneous SSc dcSSc Diffuse cutaneous SSc TGF-β Transforming growth factor β TβRI and TβRII Transforming growth factor β receptors IQR Interquartile range ANA Antinuclear antibodies Anti-Scl-70 Anti-DNA-topoisomerase I antibodies ACA Anticentromere antibodies ATS American Thoracic Society ESSG European Scleroderma Study Group mRSS Modified Rodnan skin score CRP C-reactive protein 1 Institute of Rheumatology, Prague, Czech Republic. 2Department of Rheumatology, First Faculty of Medicine, Charles University, Prague, Czech Republic. 3Department of Physiotherapy, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic. 4Department of Methodology, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic. 5Department of Internal Medicine III and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany. *email: Scientific Reports | (2021) 11:1 | https://doi.org/10.1038/s41598-020-79139-8 1 Vol.:(0123456789) www.nature.com/scientificreports/ ESR Erythrocyte sedimentation rate HRCT High-resolution computed tomography PFT Pulmonary function tests FVC Forced vital capacity FEV1 Forced expiratory volume in one second DLCO Diffusing capacity for carbon monoxide SpO2 Blood oxygen saturation level GI Gastrointerstinal ivolvement ILD Interstitial lung disease PAH Pulmonary arterial hypertension CI Cardiac involvement RI Renal involvement GC Low dose glucocorticoids (i.e. ≤ 10 mg/day of prednisone) MTX Methotrexate CPA Cyclophosphamide AZA Azathioprine MMF Mycophenolate mofetil RA Rheumatoid arthritis axSpA Axial spondyloarthritis NF-κB Nuclear factor kappa-light-chain-enhancer of activated B cells TLR Toll-like receptor ERK Extracellular signal-regulated kinases IL-6R Interleukin 6 receptor STAT Signal transducer and activator of transcription Systemic sclerosis (scleroderma, SSc) is an autoimmune connective tissue disease characterized by vasculopathy and fibrotic changes in multiple organs, particularly the skin and the lungs. It is a rare chronic rheumatic disorder of a complex a etiopathogenesis1. Genetic and environmental factors and epigenetics most probably underlie susceptibility to this disease. Scleroderma is traditionally seen as a prototypical multi-system fibrotic disorder mediated by transforming growth factor (TGF)-β and fibroblasts, which produce excessive extracellular matrix proteins such as collagen. However, another hypothesis attributes this disease to the malfunction of the connective tissue repair mechanism in response to injury1,2. Patients with SSc can be categorized into two subgroups based on the affected regions: diffuse cutaneous (dc) SSc with proximal involvement, and limited cutaneous (lc) SSc with fibrosis of the skin distal to the elbows or knees, and occasionally of the face and n eck1. Internal organ complications associated with SSc contribute to its highest morbidity and mortality amongst inflammatory rheumatic disorders3. Up to 80% of SSc patients develop interstitial lung disease (ILD), and 25–30% of these patients present with the progressive phenotype. The underlying mechanisms of fibrotic changes in ILD associated with SSc (SSc-ILD) include mesenchymal cell activation, structural changes to epithelial and endothelial cells, and cellular l esions4. Currently, ILD is the leading cause of death for SSc patients, accounts for up to 30% of deaths, and has a 10-year mortality of up to 40%5. Clinical management of SSc-ILD is challenging and relies on the identification of clinically meaningful disease, assessment of response to pharmacological therapy, and implementation of routine m onitoring3. Circulating biomarkers reflect relevant physiological or pathological processes, thus may serve as tools for diagnosis, risk evaluation, and prediction of treatment response or safety monitoring. However, disease-specific biomarkers that could be used in routine clinical practice are lacking6. Recently, several new promising or effective therapies for SSc-ILD have become available. Therefore, there is an unmet need for disease- or organ-specific biomarkers to assess and to predict treatment r esponse6,7. Heat shock proteins (Hsp) are chaperone proteins first described in 1962 in Drosophila based on their increased expression at elevated temperatures8. More recent studies found that Hsp are also induced by other forms of cellular stress (e.g. increased pH, disruption of homeostasis, viral infection, reparative healing, and tissue remodeling, etc.)9,10. Under physiological conditions as well as during stress response, Hsp recognize and adhere to misfolded proteins in non-native conformations and protect these client proteins against irreversible degradation11. In this study, we focused on Hsp90, which is highly conserved and ubiquitously expressed in eukaryotic organisms and in bacteria. It is crucial for many physiological processes, e.g., the cell cycle regulation, cellular apoptosis, protein degradation, and other signalling pathways12–14. The abundant Hsp90 ac (...truncated)