We suggest that GCs are therapeutic agents for CRSwNP by inhibiting tissue remodeling through their inhibitory effect on Src/Akt/mTOR signaling pathway. This article is protected by copyright. All rights reserved.

Mesenchymal stem cells (MSCs) are multipotent progenitor cells in adult tissues. This study aimed to investigate nasal polyp (NP) tissues as a potential new source of multipotent MSCs that maintain their stemness and differentiation potential following multiple rounds of passaging. NP tissues were obtained from 10 patients during endoscopic sinus surgery. After isolating and culturing NPderived MSCs (npMSCs), the expression levels of the surface markers CD34, CD44, CD45, CD73, CD90, CD105, CD106, CD146 and human leukocyte antigens-class II DR antigen (HLA-DR) were estimated by flow cytometry. NpMSCs were cultured in chondrogenic, osteogenic, adipogenic, or neurogenic differentiation medium. The differentiation potential of npMSCs was analyzed by Alcian blue, alizarin red S, oil red O, and immunocytochemical staining and reverse transcription-polymerase chain reaction. The clonogenic potential of npMSCs was measured using a colony-forming unit assay. Cell proliferation of npMSCs was measured using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. Flow cytometry analysis revealed that npMSCs were negative for hematopoietic lineage markers (CD34, CD45, and HLA-DR) and positive for MSC markers (CD44, CD73, CD90, and CD105). The npMSCs differentiated into osteogenic, adipogenic, chondrogenic, and neurogenic lineages, respectively. Chondrogenically differentiated npMSCs were stained with Alcian blue, osteogenically differentiated npMSCs were stained with alizarin red S, and adipogenically differentiated npMSCs were stained with oil red O. Real-time polymerase chain reaction results showed that the differentiated npMSCs expressed the respective differentiation markers (Sox 9 and Col2A for chondrogenesis, Runx2 and osteocalcin for osteogenesis, fatty acid-binding protein 4 and peroxisome proliferator-activated receptor for adipogenesis, TuJ1, neurofilament light chain, and neurofilament heavy chain for neurogenesis). There were no significant differences in the clonogenic potential and proliferation rate between early and late passage npMSCs. These results show that npMSCs possess the characteristics of MSCs in terms of morphology, multipotent differentiation capacity, cell surface marker expression, and clonogenicity. Thus, npMSCs may represent an alternative source of MSCs.

Pirfenidone has an inhibitory effect on TGF-β1-induced migration, myofibroblast differentiation (α-SMA), extracellular matrix accumulation, and collagen contraction by blocking the phosphorylation of Smad2/3 pathways in NPDFs. Thus, pirfenidone may inhibit TGF-β1-induced extracellular matrix by regulating Smad2/3.

HSP47 is required for the production of collagen and serves an important role in tissue remodeling, a pathophysiologic mechanism of chronic rhinosinusitis (CRS). We investigated the relationship between HSP47 expression and tissue remodeling in CRS. We also determined the underlying molecular mechanisms of TGF-β1-induced HSP47 and extracellular matrix (ECM) production in nasal fibroblasts. HSP47, α-SMA, fibronectin, and collagen type I expression levels were measured using real-time PCR, western blotting, and immunofluorescence staining. Fibroblast migration was analyzed using scratch and transwell migration assays. Contractile activity was measured with a collagen gel contraction assay. HSP47 is increased in patients with CRS without nasal polyps. TGF-β1 induced HSP47 expression in nasal fibroblasts. Myofibroblast differentiation and ECM production, which are induced by TGF-β1, were inhibited by siHSP47. We also confirmed that the Smad2/3 signaling pathway is involved in TGF-β1-induced HSP47 expression in nasal fibroblasts. In a functional assay, TGF-β1-enhanced migration and contraction ability were inhibited by HSP47 knockout. Glucocorticoid reversed the stimulatory effects of TGF-β1 on HSP47 expression and ECM production in nasal fibroblasts and ex vivo organ cultures. HSP47 expression is involved in TGF-β1-induced myofibroblast differentiation and ECM production through the Smad2/3 signaling pathway, which might contribute to tissue remodeling in chronic rhinosinusitis.

CSE has a stimulatory effect on VEGF expression through the TLR4, ROS, MAPK, and NF-kappaB signaling pathway in nasal fibroblasts.