Failure propagation in multicellular tissues as mediated by advective flow

Aging is not just due to the death of cells but due to systemic failures due to the accumulation of malfunctions in a network of interdependent components. Here we experimentally and theoretically study how failure propagates in a synthetic multicellular tissue, as mediated by cooperative factors transported by diffusion as well as advective flow. We first experimentally show that fluid flow induces a reduced death rate upstream. Based on this observation, we then develop a model where cells secrete cooperative factors that enhance their survival which diffuse, decay, and advect in space according to the laws of fluid dynamics. From this model, we derive further predictions for the conditions for which a propagating front of failure should form, and its velocity.