PUBLICATION | Active mucus–cilia hydrodynamic coupling

A new article about active mucus–cilia hydrodynamic coupling has recently been published in Nature Physics. This article is the fruit of a collaboration between AMU, CINAM, IBDM, IRMB and M2P2.

Entitlted “Active mucus–cilia hydrodynamic coupling drives self-organization of human bronchial epithelium“, this article in Nature Physics (August 10) is the result of a colaboration between 3 of our partner institute (CINAM, IBDM and M2P2), AMU and the IRMB. The article is signed by Etienne Loiseau (CINAM), Simon Gsell (M2P2), Aude Nommick (IBDM), Charline Jomard (AMU), Delphine Gras (IRMB), Pascal Chanez (AMU), Umberto D’Ortona (M2P2), Laurent Kodjabachian (IBDM), Julien Favier (M2P2) & Annie Viallat (CINAM).

Abstract: The respiratory tract is protected by mucus, a complex fluid transported along the epithelial surface by the coordinated beating of millions of microscopic cilia, hence the name of mucociliary clearance. Its impairment is associated with all severe chronic respiratory diseases. Yet, the relationship between ciliary density and the spatial scale of mucus transport, as well as the mechanisms that drive ciliary-beat orientations are much debated. Here, we show on polarized human bronchial epithelia that mucus swirls and circular orientational order of the underlying ciliary beats emerge and grow during ciliogenesis, until a macroscopic mucus transport is achieved for physiological ciliary densities. By establishing that the macroscopic ciliary-beat order is lost and recovered by removing and adding mucus, respectively, we demonstrate that cilia–mucus hydrodynamic interactions govern the collective dynamics of ciliary-beat directions. We propose a two-dimensional model that predicts a phase diagram of mucus transport in accordance with the experiments. This paves the way to a predictive in silico modelling of bronchial mucus transport in health and disease.