Local Analysis of Heterogeneous Intracellular Transport: Slow and Fast moving Endosomes

TL;DR

This study analyzes the heterogeneous intracellular transport of endosomes by splitting their trajectories into slow and fast groups, revealing distinct statistical properties and supporting a fractional Brownian motion model.

Contribution

It introduces a method to separately analyze slow and fast endosome trajectories, uncovering their distinct local anomalous exponents and diffusion coefficients, advancing understanding of intracellular transport heterogeneity.

Findings

Both ensembles exhibit exponential and power law distributions of local parameters.

Heterogeneous fractional Brownian motion effectively models endosome dynamics.

Local analysis confirms the heterogeneity in anomalous diffusion properties.

Abstract

Trajectories of endosomes inside living eukaryotic cells are highly heterogeneous in space and time and diffuse anomalously due to a combination of viscoelasticity, caging, aggregation and active transport. Some of the trajectories display switching between persistent and anti-persistent motion while others jiggle around in one position for the whole measurement time. By splitting the ensemble of endosome trajectories into slow moving sub-diffusive and fast moving super-diffusive endosomes, we analyzed them separately. The mean squared displacements and velocity auto-correlation functions confirm the effectiveness of the splitting methods. Applying the local analysis, we show that both ensembles are characterized by a spectrum of local anomalous exponents and local generalized diffusion coefficients. Slow and fast endsomes have exponential distributions of local anomalous exponents and power law distributions of generalized diffusion coefficients. This suggests that heterogeneous fractional Brownian motion is an appropriate model for both fast and slow moving endosomes. This article is part of a Special Issue entitled: "Recent Advances In Single-Particle Tracking: Experiment and Analysis" edited by Janusz Szwabi\'nski and Aleksander Weron.