Nuclear Positioning and Its Translational Dynamics Are Regulated by Cell Geometry.
Biophysical Journal. 2017-05-01; 112(9): 1920-1928
DOI: 10.1016/j.bpj.2017.03.025
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The collective activity of several molecular motors and other active processes
generate large forces for directional motion within the cell, which is vital for
a multitude of cellular functions such as migration, division, contraction,
transport, and positioning of various organelles. These processes also generate a
background of fluctuating forces, which influence intracellular dynamics and
thereby create unique biophysical signatures, which are altered in many diseases.
In this study, we have used the nucleus as a probe particle to understand the
microrheological properties of altered intracellular environments by using
micropatterning to confine cells in two structurally and functionally extreme
geometries. We find that nuclear positional dynamics is sensitive to the
cytoskeletal organization by studying the effect of actin polymerization and
nuclear rigidity on the diffusive behavior of the nucleus. Taken together, our
results suggest that mapping nuclear positional dynamics provides important
insights into biophysical properties of the active cytoplasmic medium. These
biophysical signatures have the potential to be used as an ultrasensitive
single-cell assay for early disease diagnostics.