Hans Clevers

@hansclevers.bsky.social

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-Scientist interested in Wnt signaling, stem cells and organoids -Professor and group leader in Utrecht at the Hubrecht Institute and the Princess Maxima Center

Tissue actively maintain mechanical homeostasis by removing weaker cells through live cell extrusion.
Point-ablation at the cell base. In this representative example, the point-ablation was targeted at the cell base, just below the nucleus of the cell in the center of the white box.
"Weaker" less contractile cells that can not sustain the tension level of their neighbours in the tissue preferentially extruded.
Local photoactivation of optogenetic opto-Arhgef11 organoids. A group of cells of an opto-Arhgef11 organoid was photoactivated using 488 nm light (with box) causing a local contraction of the organoid.
Basal myosin dynamics at synthetic villus tip. Confocal movie showing the basal myosin network and its dynamics in intestinal organoid cells grown on the synthetic villus.
Cell extrusion in myosin reporter intestinal organoid. Light-sheet movie of an organoid co-expressing Myosin-II-tdTomato (green) and an H2B-GFP nuclear marker (magenta) showing an extruding cell in the cross-section. The basal surface faces the top right, the organoid lumen is in the lower left.
Laser ablation at the villus tip revealed that the tissue is under tension and cells are not under compression.
Intestinal organoids expressing a nuclear reporter allowed for cell tracking and analysis of cell extrusion. Nuclei marked with H2B-mCherry are depth-colored.
The intestine constantly renews itself by generation of new cells from stem cells and removal of old cells through cell extrusion.
Animation: Jeroen Huijben
Image credit: Silvia Berger, Saba Rezakhani, Irineja Cubela (Roche's IHB) About the image: Kidney organoids with glomeruli - paraffin section stained for nuclei (blue). Glomerular markers: Nephrin (red) and Synaptopodin (green), and tubule marker EpCam (grey). Acquired with Nikon Ti2 25x water immersion objective.