Modulation of Cilia Motility by Vortex-Ultrasound-Induced Shear Stress.

Area of Science:

• Cell Biology
• Biophysics
• Mechanobiology

Background:

• Precise, noninvasive modulation of primary ciliary mechanotransduction is challenging.
• Existing methods (microfluidics, optical tweezers, magnetic actuation, genetic/optogenetic techniques) lack spatiotemporal precision and in vivo applicability.

Purpose of the Study:

• To introduce vortex ultrasound (VUS) as a noninvasive method for modulating primary ciliary mechanotransduction.
• To demonstrate VUS's ability to generate localized shear stress and activate ciliary signaling pathways.

Main Methods:

• Utilized a 3.5 MHz transducer to generate vortex ultrasound (VUS).
• Applied VUS to induce localized shear stress via helical acoustic streaming.
• Measured VUS-induced shear stress and cilia deflection (up to 80°).
• Assessed VUS-induced calcium influx via ciliary ion channels (TRPV4, TRPP2).

Main Results:

• VUS generated approximately 5-fold higher shear stresses than conventional focused ultrasound.
• VUS successfully induced significant cilia deflections.
• Mechanical stimulation by VUS triggered calcium influx through TRPV4 and TRPP2 channels.
• Demonstrated direct activation of primary ciliary mechanotransduction by VUS.

Conclusions:

• VUS provides a scalable physical modality for precise, noninvasive modulation of primary ciliary mechanotransduction.
• VUS is a promising tool for investigating and manipulating cilia-associated signaling pathways in biological systems.
• This approach overcomes limitations of current techniques for in vivo applications.