Nuclear IL-33 in Fibroblasts Promotes Skin Fibrosis

Abstract

Systemic sclerosis (SSc) is a complex and poorly understood connective tissue disease characterized by diffuse fibrosis in several organs, especially the skin ( Asano, 2017 Asano Y. Recent advances in the treatment of skin involvement in systemic sclerosis. Inflamm Regen. 2017; 37: 12 Crossref Scopus (6) Google Scholar , Bhattacharyya et al., 2012 Bhattacharyya S. Wei J. Tourtellotte W.G. Hinchcliff M. Gottardi C.G. Varga J. Fibrosis in systemic sclerosis: common and unique pathobiology. Fibrogenesis Tissue Repair. 2012; 5: S18 Crossref Scopus (30) Google Scholar , Denton et al., 2006 Denton C.P. Black C.M. Abraham D.J. Mechanisms and consequences of fibrosis in systemic sclerosis. Nat Clin Pract Rheumatol. 2006; 2: 134-144 Crossref Scopus (156) Google Scholar ). Interleukin (IL)-33 is found to regulate tissue fibrosis in multiple organs ( Kotsiou et al., 2018 Kotsiou O.S. Gourgoulianis K.I. Zarogiannis S.G. IL-33/ST2 Axis in Organ Fibrosis. Frontiers in immunology. 2018; 9: 2432 Crossref PubMed Scopus (96) Google Scholar , Xu et al., 2016 Xu J. Zheng J. Song P. Zhou Y. Guan S. IL33/ST2 pathway in a bleomycininduced pulmonary fibrosis model. Mol Med Rep. 2016; 14: 1704-1708 Crossref Scopus (13) Google Scholar ). However, the exact role of IL-33 in fibrosis remains controversial ( Kotsiou et al., 2018 Kotsiou O.S. Gourgoulianis K.I. Zarogiannis S.G. IL-33/ST2 Axis in Organ Fibrosis. Frontiers in immunology. 2018; 9: 2432 Crossref PubMed Scopus (96) Google Scholar ). Previous studies have shown a pro-fibrotic role for IL-33 cytokine through its receptor, interleukin-1 receptor-like 1(IL1RL1 or ST2), regulating the secretion of pro-fibrotic cytokine, IL-13, from eosinophils, M2 macrophages and type 2 innate lymphoid cells (ILC2) ( Li et al., 2014 Li D. Guabiraba R. Besnard A.G. Komai-Koma M. Jabir M.S. Zhang L. et al. IL-33 promotes ST2-dependent lung fibrosis by the induction of alternatively activated macrophages and innate lymphoid cells in mice. The Journal of allergy and clinical immunology. 2014; 134: 1422-1432 e11 Abstract Full Text Full Text PDF PubMed Scopus (268) Google Scholar , Rankin et al., 2010 Rankin A.L. Mumm J.B. Murphy E. Turner S. Yu N. McClanahan T.K. et al. IL-33 induces IL-13-dependent cutaneous fibrosis. J Immunol. 2010; 184: 1526-1535 Crossref PubMed Scopus (188) Google Scholar , Wu et al., 2018 Wu L. Luo Z. Zheng J. Yao P. Yuan Z. Lv X. et al. IL-33 Can Promote the Process of Pulmonary Fibrosis by Inducing the Imbalance Between MMP-9 and TIMP-1. Inflammation. 2018; 41: 878-885 Crossref PubMed Scopus (30) Google Scholar ). However, IL-33 can also play an anti-fibrotic role through the induction of ILC2 cells and regulatory T cells in several organs including the skin ( Cheon et al., 2022 Cheon S.Y. Park J.H. Ameri A.H. Lee R.T. Nazarian R.M. Demehri S. IL-33/Regulatory T-Cell Axis Suppresses Skin Fibrosis. The Journal of investigative dermatology. 2022; Google Scholar , Garbern et al., 2019 Garbern J.C. Williams J. Kristl A.C. Malick A. Rachmin I. Gaeta B. et al. Dysregulation of IL-33/ST2 signaling and myocardial periarteriolar fibrosis. J Mol Cell Cardiol. 2019; 128: 179-186 Abstract Full Text Full Text PDF Scopus (12) Google Scholar , Riedel et al., 2017 Riedel J.H. Becker M. Kopp K. Duster M. Brix S.R. Meyer-Schwesinger C. et al. IL-33-Mediated Expansion of Type 2 Innate Lymphoid Cells Protects from Progressive Glomerulosclerosis. J Am Soc Nephrol. 2017; 28: 2068-2080 Crossref Scopus (71) Google Scholar ). Thus, it is critical to determine the full spectrum of IL-33 effect in fibrosis to develop optimal therapies for its utilization in the treatment of SSc and other fibrosis-associated diseases.