The Role of the Optical Stretcher Is Crucial in the Investigation of Cell Mechanics Regulating Cell Adhesion and Motility

Abstract

The mechanical properties of cells, tissues, and the surrounding extracellular matrix environment play important roles in the process of cell adhesion and migration. In physiological and pathological processes of the cells, such as wound healing and cancer, the capacity to migrate through the extracellular matrix is crucial. Hence biophysical techniques were used to determine the mechanical properties of cells that facilitate the various migratory capacities. Since the field of mechanobiology is rapidly growing, the reliable and reproducible characterization of cell mechanics is required that facilitates the adhesion and migration of cells. One of these cell mechanical techniques is the optical stretching device, which was originally developed to investigate the mechanical properties of cells, such as the deformation of single cells in suspension. After discussing the strengths and weaknesses of the technology, the latest findings in optical stretching-based cell mechanics are presented in this review. Finally, the mechanical properties of cells are correlated with their migratory potential and it is pointed out how the inhibition of biomolecules that contribute to the to the maintenance of cytoskeletal structures in cells affect their mechanical deformability.

Effect of PAK Inhibition on Cell Mechanics Depends on Rac1

“…The optical cell stretcher is a dual-beam laser trap that can trap and deform single suspended cells by optically induced stress. In detail, a microfluidic flow chamber is mounted on an inverted phase-contrast microscope (Zeiss Axio Observer Z1, Zeiss, Oberkochen, Germany) and connected to two laser beams facing each other (Kunschmann et al, , 2019Mierke, 2019). Individual spherical cells were transported with a microfluidic pump system in front of the two laser beams and cellular deformation was recorded by a CCD camera (Basler A622f, Basler Vision Technologies, Switzerland; Guck et al, 2005;Lincoln et al, 2007;Mierke et al, 2017;Kunschmann et al, 2017Kunschmann et al, , 2019.…”

Effect of Nuclear Stiffness on Cell Mechanics and Migration of Human Breast Cancer Cells

“…There is still the general hypothesis that cancer cell mechanics contributes "universally" to the 3D migration, as cancer cells with an increased invasive capacity have displayed increased 3D motility and are more deformable and hence softer than cancer cells with a decreased invasive capacity (Guck et al, 2005;Cross et al, 2007;Remmerbach et al, 2009;Fritsch et al, 2010;Runge et al, 2014;Lekka, 2016;Meinhövel et al, 2018). In contrast, it has been hypothesized that a "universal" mechanism for all cancer cell types (Jonietz, 2012;Alibert et al, 2017) or even all cell types (Mierke, 2019b) is probably not suitable for migration into 3D extracellular matrix confinements due to the multiple biochemical and genetic differences among the vastly different cell types. Instead, there may also be other mechanisms employed that explain why even the opposite behavior can be observed, which means that even the stiffer cancer cells or stiffer fibroblasts, migrate more efficiently into 3D extracellular matrix confinements (Mierke et al, 2008;Mierke, 2011;Kunschmann et al, 2017Kunschmann et al, , 2019.…”

Inhomogeneities in 3D Collagen Matrices Impact Matrix Mechanics and Cancer Cell Migration

“…Obviously, distinct parameters of the microenvironmental scaffold can stimulate and support the migration of specific cancer cells, whereas other parameters seem to rather constrain and impair the invasiveness of specific cancer cells (Wolf et al, 2013;Charras and Sahai, 2014). However, if these parameters impact the migration of all cancer cell types, or even all types of cells, in a universal manner is still on debate (Mierke, 2019b).…”