Pathologic Fibroblasts in Idiopathic Subglottic Stenosis Amplify Local Inflammatory Signals

Objective To characterize the phenotype and function of fibroblasts derived from airway scar in idiopathic subglottic stenosis (iSGS) and to explore scar fibroblast response to interleukin 17A (IL-17A). Study Design Basic science. Setting Laboratory. Subjects and Methods Primary fibroblast cell lines from iSGS subjects, idiopathic pulmonary fibrosis subjects, and normal control airways were utilized for analysis. Protein, molecular, and flow cytometric techniques were applied in vitro to assess the phenotype and functional response of disease fibroblasts to IL-17A. Results Mechanistically, IL-17A drives iSGS scar fibroblast proliferation ( P < .01), synergizes with transforming growth factor ß1 to promote extracellular matrix production (collagen and fibronectin; P = .04), and directly stimulates scar fibroblasts to produce chemokines (chemokine ligand 2) and cytokines (IL-6 and granulocyte-macrophage colony-stimulating factor) critical to the recruitment and differentiation of myeloid cells ( P < .01). Glucocorticoids abrogated IL-17A-dependent iSGS scar fibroblast production of granulocyte-macrophage colony-stimulating factor ( P = .02). Conclusion IL-17A directly drives iSGS scar fibroblast proliferation, synergizes with transforming growth factor ß1 to promote extracellular matrix production, and amplifies local inflammatory signaling. Glucocorticoids appear to partially abrogate fibroblast-dependent inflammatory signaling. These results offer mechanistic support for future translational study of clinical reagents for manipulation of the IL-17A pathway in iSGS patients.

EPITHELIAL-MESENCHYMAL AND MESENCHYMAL-EPITHELIAL TRANSITION, PATHOGENESIS, REGULATION, THERAPY

The review considered the issues of epithelial-mesenchymal transition (EMT) and its role in inflammation, fibrosis, tumor growth. There were analyzed mechanisms and classification of EMT. A comparison of different forms of EMTs was performed. The important role of EMT in the formation of metastasis-initiating cells was noted. There were presented data on the role of fibroblasts in fibrosis of the lung, carcinogenesis. Stimulators and inhibitors of EMTs were summarized. There were considered intracellular paths that were associated with the development of the EMT under the influence of transforming growth factor ß1 (TGF - ß1). It also induced the development of local hypothyroidism, for easy expression of oncofetal genes, which was especially important in tumor growth. Therapy EMT was associated with blocking the actions of TGF - ß1 and was an important area in anticancer therapy.