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bioRxiv · 10.1101/2021.02.28.433274

Collagen polarization provides a structural memory for the elongation of epithelial anlage.

Katsuno-Kambe, H.·Teo, J. L.·Ju, R. J.·Hudson, J. E.·Stehbens, S. J.·Yap, A. S.
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Abstract

Epithelial networks are commonly generated by processes where multicellular aggregates elongate and branch. Here we focus on understanding cellular mechanisms for elongation, using an organotypic culture system as a model of mammary epithelial anlage. Isotropic cell aggregates broke symmetry and slowly elongated when transplanted into collagen 1 gels. The elongating regions of aggregates displayed enhanced cell proliferation that was necessary for elongation to occur. Strikingly, this loco-regional increase in cell proliferation occurred where collagen 1 fibrils reorganized into bundles which were polarized with the elongating aggregates. Applying external stretch as a cell-independent way to reorganize the ECM, we found that collagen polarization stimulated regional cell proliferation to precipitate symmetry-breaking and elongation. This required {beta}1-integrin and ERK signaling. We propose that collagen polarization supports epithelial anlagen elongation by stimulating loco-regional cell proliferation. This could provide a long-lasting structural memory of the initial axis that is generated when anlage break symmetry.

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Katsuno-Kambe, H., Teo, J. L., Ju, R. J., Hudson, J. E., Stehbens, S. J., Yap, A. S.. 2021-02-28. Collagen polarization provides a structural memory for the elongation of epithelial anlage.. https://doi.org/10.1101/2021.02.28.433274

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