The role and importance of mechanical properties of cells and tissues in cellular function, development and disease has widely been acknowledged, however standard techniques currently used to assess them -as for example Atomic Force Microscopy- exhibit intrinsic limitations in term of spatial resolution, 3D capability and invasiveness.
Recently, Brillouin microscopy, a type of optical elastography, has emerged as a non-destructive, label- and contact-free method that can probe the viscoelastic properties of biological samples with diffraction-limited resolution in 3D. This led to increased attention amongst the biophysical, biological, and medical research communities.
After discussing the technique and its potentiality, as an example we report few examples of application in tissues, cells, and subcellular structures. Among them the investigation of the mechanical properties of the stress granules in presence of mutated FUS protein, giving insights on the critical aggregation step underlying the neurodegenerative ALS disease. Altered cellular biomechanics have been implicated as key photogenic triggers in age-related diseases. An aberrant liquid-to-solid phase transition, observed in in vitro reconstituted droplets of FUS protein, has been recently proposed as a possible pathogenic mechanism for amyotrophic lateral sclerosis (ALS). Whether such transition occurs in cell environments is currently unknown because of the limited measuring capability of the existing techniques, which are invasive or lack of subcellular resolution. The Brillouin microscopy seems to be the tool capable to solve this issue.
Amos Maritan
