Paris Postdoc Seminar – Artur Ruppel

Invited by the Institut Jacques Monod, Artur Ruppel ( Institut Pasteur) will present a Paris Postdoc seminar on the theme:

Designing minimalistic tissue models: A reductionist approach to dissect collective cell behavior

Abstract:

Living tissues are active materials whose collective behavior emerges from the mechanical  properties and interactions of their cellular constituents. Understanding how cell-scale mechanics give rise to tissue-scale phenomena remains challenging due to the inherent complexity of biological systems. This seminar presents a reductionist strategy using micropatterning to create minimal tissue models that isolate specific cellular processes for quantitative study. The first part addresses the mechanics of T1 transitions in tissues, the neighbor exchange events driving tissue remodeling during morphogenesis. Using cell quadruplets on cross-shaped micropatterns, we experimentally measured the effective energy landscape of T1 transitions and validated vertex model predictions, revealing how geometric constraints set energy barriers that active forces must overcome. The second part turns to mechanical heterogeneity in tissues. While cell-to-cell variability is ubiquitous, whether it functions as a driver of collective behavior or merely represents noise remains unclear. Using controlled mixtures of wild-type and vimentin-knockout glioblastoma cells, we systematically investigate how the degree and spatial organization of mechanical heterogeneity shapes tissue mechanics.