Apical surface supracellular mechanical properties in polarized epithelium using noninvasive acoustic force spectroscopy

Nat Commun. 2017 Oct 18;8(1):1030. doi: 10.1038/s41467-017-01145-8.

Abstract

Maintenance of epithelial tissue integrity requires coordination between cell-cell adherens junctions, tight junctions (TJ), and the perijunctional actomyosin cytoskeleton. Here we addressed the hypothesis that alterations in TJ structure and remodeling of the actomyosin cytoskeleton modify epithelial mechanics. Current methods to measure supracellular mechanical properties disrupt intact monolayers, therefore, we developed a novel method using noncontact acoustic frequency-modulation atomic force microscopy (FM-AFM) and tested it on MDCK polarized monolayers. Our results show that double knockdown (dKD) of ZO-1/ZO-2 elevates the apical epithelial tension and effective viscosity. Interestingly, epithelial tension is more sensitive to inhibition of myosin II ATPase activity than to inhibition of ROCK activity, but viscosity is highly sensitive to both. Additionally, we showed epithelial intercellular pulling forces at tricellular junctions and adhesion forces in dKD cells are elevated with an increase in contractility. In conclusion, FM-AFM enables the physiological and quantitative investigation of mechanics in intact epithelium.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Actomyosin / metabolism
  • Animals
  • Biomechanical Phenomena
  • Cell Polarity
  • Dogs
  • Epithelium / chemistry*
  • Epithelium / metabolism
  • Madin Darby Canine Kidney Cells
  • Spectrum Analysis
  • Tight Junctions / chemistry
  • Tight Junctions / metabolism
  • Zonula Occludens-1 Protein / genetics
  • Zonula Occludens-1 Protein / metabolism
  • Zonula Occludens-2 Protein / genetics
  • Zonula Occludens-2 Protein / metabolism

Substances

  • Zonula Occludens-1 Protein
  • Zonula Occludens-2 Protein
  • Actomyosin