Quantifying Tensile Forces at Cell–Cell Junctions with a DNA-based Fluorescent Probe

Abstract

Cells are physically contacting with each other. Direct and precise quantification of forces at cell-cell junctions is still challenging. Herein, we have developed a DNA-based ratiometric fluorescent probe, termed DNAMeter, to quantify intercellular tensile forces. These lipidmodified DNAMeters can spontaneously anchor onto live cell membranes. The DNAMeter consists of two self-assembled DNA hairpins of different force tolerance. Once the intercellular tension exceeds the force tolerance to unfold a DNA hairpin, a specific fluorescence signal will be activated, which enables the real-time imaging and quantification of tensile forces. Using Ecadherin-modified DNAMeter as an example, we have demonstrated an approach to quantify, at the molecular level, the magnitude and distribution of E-cadherin tension among epithelial cells.Compatible with readily accessible fluorescence microscopes, these easy-to-use DNA tension probes can be broadly used to quantify mechanotransduction in collective cell behaviors.

Spectroscopic Analysis of a Library of DNA Tension Probes for Mapping Cellular Forces at Fluid Interfaces

“…14,26 A similar approach was also used to measure cadherin tension and density in epithelial cell−cell junctions. 27 In these approaches, a third dye is incorporated into the tension probe to serve as a density reporter. One step toward measuring receptor forces in three-dimensional (3D), ratiometric DNA probes were also recently incorporated into mechanofluorescent DNA hydrogels.…”

“…The most common method to measure forces in a system with changing probe density relies on ratiometric intensity-based imaging. This was first demonstrated by Ma et al when mapping T cell receptor forces and later was applied by Nowosad et al when measuring B cell receptor forces on fluid membranes. , A similar approach was also used to measure cadherin tension and density in epithelial cell–cell junctions . In these approaches, a third dye is incorporated into the tension probe to serve as a density reporter.…”