Bistability of Dielectrically Anisotropic Nematic Crystals and the Adaptation of Endothelial Collectives to Stress Fields. Issue 16 (28th March 2022)

• Record Type: Journal Article
• Authors: Stefopoulos, Georgios; Lendenmann, Tobias; Schutzius, Thomas M.; Giampietro, Costanza; Roy, Tamal; Chala, Nafsika; Giavazzi, Fabio; Cerbino, Roberto; Poulikakos, Dimos; Ferrari, Aldo
• Is Part Of: Advanced science. Volume 9:Issue 16(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-28
• Subjects: collective cell behavior -- endothelia -- monolayers -- nematic -- polarization -- wall shear stress; Science -- Periodicals; 505
• DOI: 10.1002/advs.202102148
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Endothelial monolayers physiologically adapt to flow and flow‐induced wall shear stress, attaining ordered configurations in which elongation, orientation, and polarization are coherently organized over many cells. Here, with the flow direction unchanged, a peculiar bi‐stable (along the flow direction or perpendicular to it) cell alignment is observed, emerging as a function of the flow intensity alone, while cell polarization is purely instructed by flow directionality. Driven by the experimental findings, the parallelism between endothelia is delineated under a flow field and the transition of dual‐frequency nematic liquid crystals under an external oscillatory electric field. The resulting physical model reproduces the two stable configurations and the energy landscape of the corresponding system transitions. In addition, it reveals the existence of a disordered, metastable state emerging upon system perturbation. This intermediate state, experimentally demonstrated in endothelial monolayers, is shown to expose the cellular system to a weakening of cell‐to‐cell junctions to the detriment of the monolayer integrity. The flow‐adaptation of monolayers composed of healthy and senescent endothelia is successfully predicted by the model with adjustable nematic parameters. These results may help to understand the maladaptive response of in vivo endothelial tissues to disturbed hemodynamics and the progressive functional decay of senescent endothelia. Abstract : The collective organization of endothelial cells is instructed by the flow direction and intensity, a critical aspect of the cell assembly functionality. The dynamic variation of the external flow field exposes the cellular system to a disruptive level of disorder. The emerging new picture defines endothelia as unique active tissues with their own assembly identity, characterized by an architectural hysteresis.