Cell fluorescence photo-activation as a method to select and study cellular sub populations grown in mechanically heterogeneous environments

Abstract

A central challenge of biology of development and disease is to decipher how individual cells process and respond to numerous biochemical and mechanical signals originating from the environment. Recent advances in genomic studies enabled to acquire information about populations heterogeneity, however, these so far were poorly linked with the spatial heterogeneity of biochemical and mechanical cues. Whereas, in vitro models offer superior control over spatiotemporal distribution of numerous mechanical parameters, researchers are limited by the lack of methods to select sub-populations of cells in order to understand how environmental heterogeneity directs the functional collective response. To circumvent these limitations, we present a method based on the use of photo convertible proteins, which when expressed within cells and activated with light, give a stable fluorescence fingerprint enabling subsequent sorting and lysis for genomics analysis. Using this technique, we study the spatial distribution of genetic alterations upon well characterized local mechanical stimulation within the epithelial monolayer. Our method is an in vitro alternative to laser microdissection, which so far has found a broad application in ex vivo studies.