Probing eukaryotic cell mechanics via mesoscopic simulations.

Kirill Lykov,Menglin Shang,Igor V Pivkin,Yasaman Nematbakhsh,Chwee Teck Lim,Qing Nie

doi:10.1371/journal.pcbi.1005726

Abstract

Cell mechanics has proven to be important in many biological processes. Although there is a number of experimental techniques which allow us to study mechanical properties of cell, there is still a lack of understanding of the role each sub-cellular component plays during cell deformations. We present a new mesoscopic particle-based eukaryotic cell model which explicitly describes cell membrane, nucleus and cytoskeleton. We employ Dissipative Particle Dynamics (DPD) method that provides us with the unified framework for modeling of a cell and its interactions in the flow. Data from micropipette aspiration experiments were used to define model parameters. The model was validated using data from microfluidic experiments. The validated model was then applied to study the impact of the sub-cellular components on the cell viscoelastic response in micropipette aspiration and microfluidic experiments.

Highlights

Cell mechanics has proved to be a widely used label-free biomarker to discern phenotypes, detect pathologies and more importantly, monitor existence or progression of a disease [1,2,3]
In Sections Effect of nucleus and Effect of the cell viscosity, we characterize the impact of nucleus size and cell viscosity on the mechanical response of the cell
We examined the impact of NCL on elastic modulus for medium size cell model and found that this parameter is as significant as cytoskeleton density.NCL can alter elastic modulus from 110Pa to almost 300Pa, see Fig 4(d)

Summary

Introduction

Cell mechanics has proved to be a widely used label-free biomarker to discern phenotypes, detect pathologies and more importantly, monitor existence or progression of a disease [1,2,3]. The most prominent example is the changes in cell biology and morphology when it evolves from a healthy to a cancerous state [1, 3]. The cell membrane is a viscous fluid-like matter which consists of various lipids, cholesterol, and embedded proteins. It contributes to cell viscosity, bending resistance, and incompressibility. The nucleus is the largest organelle among sub-cellular components, demonstrating solid-elastic behavior [4], and it is typically stiffer than the cell itself [5]. It is comprised of multiple components including nuclear envelope and chromatin network. Improved understanding of the role that each cell component plays towards cell mechanics may be beneficial for diagnosis and therapy of diseases [2]

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Conclusion