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Accueil > Équipes > Microtiss > Membres de l’Equipe

Artur Ruppel

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PhD Student
Laboratoire Interdisciplinaire de Physique
140 rue de la Physique - 38402 St. Martin d’Hères

artur.ruppel (AT)

I am an engineer by training who always was fascinated by the complexity and beauty of life and how it works and somehow I found my way into this team where I am able to combine my skillset developed during engineering training with my interest in biological system. My project revolves around the mechanics of simple multicellular systems, ranging from single cells to doublets and in the near future possibly quadruplets up to systems comprising up to 10-20 cells.

Most people are probably somewhat familiar with the fact that cells communicate with each other through biochemical signals that are encoded in their genes and that are mediated by proteins. What is less commonly known and which has been subject of extensive research only for the past couple of decades, is the fact that cells also exert forces onto each other and that those forces are used to transfer information between cells and help coordinate complex biological processes such as cell division, collective cell migration or even the development of a new organism.

In my project we try to get a better understanding of how these force signals travel through simple cellular systems and how they influence the shape of the system. We use a novel tool, called optogenetics, to induce transient contractions with subcellular resolution to generate force signals in our cellular systems. We use cell-adhesive micropatterns to impose boundary conditions to the shape of the system, allowing us to limit to some extent the variability of morphological and physical properties between different cellular systems. Micropatterns also allow us to methodologically vary morphological parameters of those cellular systems and to study how these parameters influence how force signals propoagate through the cellular systems. Last but not least, we use Traction Force Microscopy (TFM) to measure cell-substrate forces and image processing of immunofluorescent actin images to analyse the morphology of the system over time to study the effect of the optogenetic perturbation we imposed.

So far we managed to show that stimulation of one cell in a doublet induces a contraction of the other cell. The exact mechanism of this contraction, if it is purely passive force transmission through the second cell to the substrate or due to an active contraction of the second cell, is one of the open questions we are currently working on. We also managed to show that the amplitude of contraction of the non-stimulated cell compared to the stimulated cell depends on the morphological parameters of the doublet such as the size of the junction or the orientation of the actin structure. Which of those parameters is mainly responsible for transmitting the contraction to the non-stimulated cell is another open question we are currently working on.