A Biophysical Analysis of Cell and Nucleus Relation

Abstract

Recently, studies of nuclear motion as well as the identification of the actin cap and the LINC (linker of nucleoskeleton and cytoskeleton) complex have suggested that the cytoskeleton may regulate the position and physical properties of the nucleus. The Rho GTPase family proteins act through separate yet intertwined pathways to govern cytoskeletal remodeling, which affect diverse cell features throughout the cell. Thus, monitored biophysical changes in such features under different conditions may be correlated to their upstream Rho GTPases' signaling. In this study, we analyzed the correlation between nucleus and cell movements of single live cells in an effort to uncover the states of Rho GTPases’ signaling, the underlying contributors to cytoskeletal reorganization. Our novel approach possesses the ability to quantitatively characterize changes in cell movement behavior patterns resulting from Rho GTPase manipulation, and can further distinguish between different cell lines, which should each possess unique Rho GTPase signaling profiles. Cell motility trends predicted by this analysis are in agreement with wound healing assays of the same cells with the advantages of more insight into molecular information and the capability to monitor individual cells. Thus, this analysis can offer a rapid, convenient platform to decipher a cell motility pattern while matching it to its underlying RhoA and Rac1 activities.