PT  - JOURNAL ARTICLE
AU  - Rachel M. Lee
AU  - Leonard Campanello
AU  - Matt J. Hourwitz
AU  - Ava Omidvar
AU  - Phillip Alvarez
AU  - John T. Fourkas
AU  - Wolfgang Losert
TI  - Quantifying topography-guided actin dynamics across scales using optical flow
AID  - 10.1101/753681
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 753681
4099  - http://biorxiv.org/content/early/2019/09/03/753681.short
4100  - http://biorxiv.org/content/early/2019/09/03/753681.full
AB  - Periodic surface topographies with feature sizes comparable to those of in vivo collagen fibers are used to measure and compare actin dynamics for two representative cell types that have markedly different migratory modes and physiological purposes: slowly migrating epithelial MCF10A cells and polarizing, fast migrating, neutrophil-like HL60 cells. Both cell types exhibit reproducible guidance of actin waves (esotaxis) on these topographies, enabling quantitative comparisons of actin dynamics. We adapt a computer-vision algorithm, optical flow, to measure the directions of actin waves at the submicron scale. Clustering the optical flow into regions that move in similar directions enables micron-scale measurements of actin-wave speed and direction. Although the speed and morphology of actin waves differ between MCF10A and HL60 cells, the underlying actin guidance by nanotopography is similar in both cell types at the micron and sub-micron scales.