SB203580—A Potent p38 MAPK Inhibitor Reduces the Profibrotic Bronchial Fibroblasts Transition Associated with Asthma

Abstract

Subepithelial fibrosis is a component of the remodeling observed in the bronchial wall of patients diagnosed with asthma. In this process, human bronchial fibroblasts (HBFs) drive the fibroblast-to-myofibroblast transition (FMT) in response to transforming growth factor-β1 (TGF-β1), which activates the canonical Smad-dependent signaling. However, the pleiotropic properties of TGF-β1 also promote the activation of non-canonical signaling pathways which can affect the FMT. In this study we investigated the effect of p38 mitogen-activated protein kinase (MAPK) inhibition by SB203580 on the FMT potential of HBFs derived from asthmatic patients using immunocytofluorescence, real-time PCR and Western blotting methods. Our results demonstrate for the first time the strong effect of p38 MAPK inhibition on the TGF-β1-induced FMT potential throughout the strong attenuation of myofibroblast-related markers: α-smooth muscle actin (α-SMA), collagen I, fibronectin and connexin 43 in HBFs. We suggest the pleiotropic mechanism of SB203580 on FMT impairment in HBF populations by the diminishing of TGF-β/Smad signaling activation and disturbances in the actin cytoskeleton architecture along with the maturation of focal adhesion sites. These observations justify future research on the role of p38 kinase in FMT efficiency and bronchial wall remodeling in asthma.

β2-Microglobulin Elevates COL5A1 mRNA in the Subsynovial Connective Tissue of Patients Receiving Hemodialysis With Carpal Tunnel Syndrome

“…p38 MAPK was shown to regulate Col1a1 expression in a rat hepatic stellate cell line [ 42 ]. Further, SB203580 inhibited TGF-β-mediated COL1A1 expression in human bronchial fibroblasts [ 43 ]. Moreover, IL-17-mediated COL5A1 expression was blocked by inhibitors of the p38 MAPK signaling pathway in human small airway epithelial cells [ 44 ].…”

Hypoxia enhances anti-fibrotic properties of extracellular vesicles derived from hiPSCs via the miR302b-3p/TGFβ/SMAD2 axis

“…The results are presented as the mean fluorescence intensity of the test protein, relative to DNA fluorescence intensity in all 16 images as described previously [ 33 ]. For the analysis of activation of selected transcription factors in the tested cells, the level of fluorescence of the phosphorylated form of SMAD2 (pSMAD2) or SNAI2 measured in the area of the cell nucleus was determined [ 34 ]. The length and area of the focal contact sites (FCs) from collected images were measured in ImageJ [ 35 ].…”

Bronchial Fibroblasts from Asthmatic Patients Display Impaired Responsiveness to Direct Current Electric Fields (dcEFs)

“…Particular components of TGF-β receptor signalling pathways were pharmacologically inhibited. Specifically, recording medium that contained SB431542 (for the TGF-β receptor I itself), U0126 (for MEK1/2), SB203580 (for p38), or Y-27632 (for ROCK) (all Sigma-Aldrich, St. Louis, MO, USA) at a concentration of 10 μM (as described earlier [ 53 ]) was provided to cells during electrotactic chamber assembly, with this process occurring 30 min prior to the start of time-lapse imaging and being present throughout the experiment.…”