Undifferentiated bronchial fibroblasts derived from asthmatic patients display higher elastic modulus than their non-asthmatic counterparts

PLoS One. 2015 Feb 13;10(2):e0116840. doi: 10.1371/journal.pone.0116840. eCollection 2015.

Abstract

During asthma development, differentiation of epithelial cells and fibroblasts towards the contractile phenotype is associated with bronchial wall remodeling and airway constriction. Pathological fibroblast-to-myofibroblast transition (FMT) can be triggered by local inflammation of bronchial walls. Recently, we have demonstrated that human bronchial fibroblasts (HBFs) derived from asthmatic patients display some inherent features which facilitate their FMT in vitro. In spite of intensive research efforts, these properties remain unknown. Importantly, the role of undifferentiated HBFs in the asthmatic process was systematically omitted. Specifically, biomechanical properties of undifferentiated HBFs have not been considered in either FMT or airway remodeling in vivo. Here, we combine atomic force spectroscopy with fluorescence microscopy to compare mechanical properties and actin cytoskeleton architecture of HBFs derived from asthmatic patients and non-asthmatic donors. Our results demonstrate that asthmatic HBFs form thick and aligned 'ventral' stress fibers accompanied by enlarged focal adhesions. The differences in cytoskeleton architecture between asthmatic and non-asthmatic cells correlate with higher elastic modulus of asthmatic HBFs and their increased predilection to TGF-β-induced FMT. Due to the obvious links between cytoskeleton architecture and mechanical equilibrium, our observations indicate that HBFs derived from asthmatic bronchi can develop considerably higher static tension than non-asthmatic HBFs. This previously unexplored property of asthmatic HBFs may be potentially important for their myofibroblastic differentiation and bronchial wall remodeling during asthma development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Airway Remodeling / drug effects
  • Asthma / pathology*
  • Bronchi / cytology*
  • Bronchi / pathology*
  • Case-Control Studies
  • Cell Differentiation / drug effects
  • Elastic Modulus* / drug effects
  • Female
  • Fibroblasts / cytology*
  • Fibroblasts / drug effects
  • Fibroblasts / pathology*
  • Focal Adhesions / drug effects
  • Humans
  • Male
  • Middle Aged
  • Myofibroblasts / drug effects
  • Myofibroblasts / pathology
  • Stress Fibers / drug effects
  • Transforming Growth Factor beta1 / pharmacology

Substances

  • Transforming Growth Factor beta1

Grants and funding

This work was supported by the Polish National Science Centre (grant 2011/01/B/NZ3/00004). The Faculty of Biochemistry, Biophysics and Biotechnology of the Jagiellonian University is a beneficiary of structural funds from the European Union (Grants No: UDA-POIG.01.03.01-14-036/09-00—”Application of polyisoprenoid derivatives as drug carriers and metabolism regulators”; POIG.02.01.00-12-064/08 – “Molecular biotechnology for health”; POIG 01.02-00-109/99 “Innovative methods of stem cell applications in medicine”). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.