Molecular Compressive Force Sensor for Mapping Forces at the Cell-Substrate Interface.

Area of Science:

• Mechanobiology
• Molecular Biology
• Biophysics

Background:

• Mechanical forces are critical for cellular functions, including T cell recognition.
• Existing molecular probes primarily measure pulling forces, leaving a gap in assessing compressive forces.
• Understanding compressive forces is essential for a comprehensive view of cellular mechanotransduction.

Purpose of the Study:

• To develop and validate a novel molecular probe for measuring compressive forces in biological systems.
• To address the limitations of current mechanobiology tools by introducing a compression-sensing capability.
• To demonstrate the utility of this new probe in mapping cellular compressive forces.

Main Methods:

• Design and synthesis of a molecular compression reporter using pseudostable DNA hairpins (M-CRUSH).
• Utilized Förster Resonance Energy Transfer (FRET) to quantify hairpin folding stability under varying conditions.
• Tested M-CRUSH's sensitivity to molecular crowding and its response to compressive forces in T cells and platelets.

Main Results:

• Identified an optimal DNA hairpin sensitive to molecular crowding, showing a 7°C shift in melting temperature.
• Demonstrated M-CRUSH's ability to detect dynamic compressive forces in primary naïve T cells, sensitive to antigen presentation.
• Confirmed that cytoskeletal activity influences compressive forces and that M-CRUSH signal is probe density-dependent.

Conclusions:

• M-CRUSH effectively measures compressive forces, filling a critical gap in mechanobiology toolkits.
• The probe is modular and applicable to various cell types, including T cells and platelets.
• M-CRUSH provides a powerful new method to study the role of compression in biological processes.