A simulation of cell migration directed by a chemotactic gradient

HESSE RIZZI E; RAPACIOLI M; FLORES V

Congreso; 2º Congreso Argentino de Bioinformática y Biología Computacional; 2011

The genesis of the supra-cellular complexity of biological organisms requires the regulated developmental cell behaviors (DCBs) operating simultaneous and interactively. DCBs that possesses relevant roles are cell proliferation, cell migration, cell adhesion, cell commitment and differentiation. The aim of this study is to analyze cell migration dynamics with and without the influence of chemotactic gradients.MethodsA software was constructed to simulate cell migration under different conditions. Its design include (a) chemotactic gradient modeling, (b) modeling of migrating cells and (c) integration of both systems. Cells move randomly in space and to respond to variations in concentration of the chemotactic agent. Thus, the gradient operates as an organizer element for cell movement: cells move from low to high concentration areas of chemotactic agent. Cell migration dynamics were analyzed by means of several non-lineal methods.Signals representing the position in x and y axes (position signals) of migrating cells without the influence of a chemotactic gradient have random walk characteristics (β=2.00). The presence of a gradient produces a strong directive effect and modifies the scaling exponent (β=1.63). To analyze if the effect of the gradient can be mimicked by the introduction of a non-stationary component, the trends of the position signals of directed migrating cells were added to the position signals of random migrating cells. This procedure results in signals whose scaling indexes resemble those of directed migrating cells (β=1.76), the reconstruction of cell movement from these signals displays directed trajectories. The inverse procedure, i.e. the generation of detrended signals from position signals of directed migrating cells, results in position signals displaying random walk characteristics (β=2.07); the reconstruction of cell movement from these signals results in random walk trajectories.ConclusionSignals representative of a directed cell migration process can be described as possessing two coexisting components: a stochastic stationary component whose dynamics admits a statistical description characterizable by its scaling index and an organizer element that introduces a non stationary component that can be deterministically described as a relative simple influence that installs differences as a function of time and space.Work supported by grants from CONICET (Argentina)