The Role and Function of Monocyte-Derived Fibroblast-like Cells in Multi-Organ Fibrosis in Systemic Sclerosis

Michal Rudnik¹, Mara Stellato¹, Vincent Milleret², Przemyslaw Blyszczuk^1,3, Britta Maurer¹, Karin Klingel⁴, Joerg C. Henes⁵, Karl Sotlar⁶, Martin Ehrbar², Oliver Distler⁷ and Gabriela Kania¹, ¹Department of Rheumatology, Center of Experimental Rheumatology, University Hospital Zurich, Zurich, Switzerland, ²Department of Obstetrics, University Hospital Zurich, Zurich, Switzerland, ³Department of Clinical Immunology, Jagiellonian University Medical College, Krakow, Poland, ⁴Department of Molecular Pathology, University Hospital Tuebingen, Tuebingen, Germany, ⁵Department of Internal Medicine II, Division of Rheumatology, University Hospital Tuebingen, Tuebingen, Germany, ⁶Institute of Pathology, Ludwig Maximilians University, Munich, Germany, ⁷Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland

Meeting: 2017 ACR/ARHP Annual Meeting

Date of first publication: September 18, 2017

Keywords: fibrosis, monocytes and systemic sclerosis

Session Information

Date: Monday, November 6, 2017

Title: Systemic Sclerosis, Fibrosing Syndromes and Raynaud's – Pathogenesis, Animal Models and Genetics Poster II

Session Type: ACR Poster Session B

Session Time: 9:00AM-11:00AM

Background/Purpose:

Animal studies indicated bone marrow-derived cells as a source of pathological myofibroblasts in fibrosis of multiple organ including lungs, heart, skin and kidney. Monocytes are implicated in the pathogenesis of systemic sclerosis (SSc), however the detailed role of specific monocyte subsets in multi-organ fibrogenesis in SSc remains unclear. The aim of this study was to determine the contribution of circulating monocytes in the onset and progression of multi-organ fibrosis in SSc.

Methods:

Endomyocardial biopsies (n=10 each) from SSc patients and healthy controls were screened by immunohistochemistry. CD14⁺ monocytes isolated from peripheral blood of SSc patients and healthy donors were differentiated towards a myofibroblast phenotype by stimulation with TGF-β1, IL-4, IL-10 and IL-13 [10ng/ml each]. In addition, CD14⁺ monocytes were co-cultured in 2D and 3D models with dermal fibroblasts originated from SSc patients or healthy subjects, or with adult healthy cardiac fibroblasts. TGF-β signalling was blocked by SD208 (TGFBR1), A83-01 (SMAD2) and (5Z)-7-Oxozeaenol (TAK1) inhibitors. Gene expression and protein secretion were evaluated by qPCR, Western blot, protein array, immunofluorescence and ELISA.

Results: The myocardium, lungs and skin of SSc patients revealed an extended collagen I deposition and the presence of CD14⁺ elongated cells in the fibrotic tissue. Stimulated monocytes acquired a myofibroblast-like phenotype with increased expression of collagen I (p<0.0001), fibronectin (p<0.05), and α smooth muscle actin (α-SMA) in comparison to untreated cells. Similarly, CD14⁺ monocytes exposed to dermal or cardiac fibroblasts acquired spindle shape and expressed higher levels of profibrotic genes. The process of monocyte-to-myofibroblast differentiation employed both canonical and non-canonical TGF-β signalling pathways. Blocking of the TGF-β receptor I and canonical SMAD-dependent pathway resulted in the abrogation of collagen I secretion by monocytes (p=0.002). In contrast, TAK1 inhibitor decreased fibronectin expression, while having no effect on collagen I expression. CD14⁺ monocytes from SSc patients were characterised by higher secretion of CXCL10 (p<0.001), which was significantly decreased after cytokine stimulation (p<0.001). Additionally, a tendency towards higher secretion of CCL20, CCL22, Leukemia Inhibitory Factor and Neurotrophin-3 was observed for SSc monocytes.

Conclusion: Here we demonstrated the capability of peripheral blood monocytes to differentiate towards the functional myofibroblast phenotype, designating these cells as one of the potential sources of pathological tissue myofibroblasts in SSc. Additionally, these cells sustained pro-fibrotic cytokines secretion, highlighting their important regulatory functions in the fibrogenesis in SSc.

Disclosure: M. Rudnik, None; M. Stellato, None; V. Milleret, None; P. Blyszczuk, None; B. Maurer, AbbVie, Protagen, EMDO, Novartis, German SSc Society, 2,Pfizer, Roche, Actelion, MSD, 9,mir-29 for the treatment of systemic sclerosis, 9; K. Klingel, None; J. C. Henes, None; K. Sotlar, None; M. Ehrbar, None; O. Distler, Actelion, Bayer, BiogenIdec, Boehringer Ingelheim, ChemomAb, espeRare foundation, Genentech/Roche, GSK, Inventiva, Lilly, medac, MedImmune, Mitsubishi Tanabe Pharma, Pharmacyclics, Novartis, Pfizer, Sanofi, Sinoxa and UCB, 2,Actelion, Bayer, BiogenIdec, Boehringer Ingelheim, ChemomAb, espeRare foundation, Genentech/Roche, GSK, Inventiva, Lilly, medac, MedImmune, Mitsubishi Tanabe Pharma, Pharmacyclics, Novartis, Pfizer, Sanofi, Sinoxa and UCB, 5,mir-29 for the treatment of systemic sclerosis, 9; G. Kania, Bayer, 2.

To cite this abstract in AMA style:

Rudnik M, Stellato M, Milleret V, Blyszczuk P, Maurer B, Klingel K, Henes JC, Sotlar K, Ehrbar M, Distler O, Kania G. The Role and Function of Monocyte-Derived Fibroblast-like Cells in Multi-Organ Fibrosis in Systemic Sclerosis [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/the-role-and-function-of-monocyte-derived-fibroblast-like-cells-in-multi-organ-fibrosis-in-systemic-sclerosis/. Accessed .

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