Dresden 2026 – scientific programme
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BP: Fachverband Biologische Physik
BP 27: Cell Mechanics I
BP 27.3: Talk
Thursday, March 12, 2026, 10:15–10:30, BAR/0205
Mechanics of “apical bulkheads” in the bile canaliculi of the liver — •Matthew J. Bovyn1,2,3, Maarten P. Bebelman2, Yannis Kalaidzidis2, Marino Zerial2,4, and Pierre A. Haas1,2,3 — 1Max Planck Institute for the Physics of Complex Systems, Dresden — 2Max Planck Institute of Molecular Cell Biology and Genetics, Dresden — 3Center for Systems Biology Dresden — 4Human Technopole, Milan
In the liver, bile is transported through the network of bile canaliculi. They are bicellular tubes (“lumina”), in which the apical cortices of apposed cells bear bile pressure. When bile canaliculi must hold high pressures, either in development or disease, they generate folds protruding into the tubes, termed “apical bulkheads”. These structures are under tension and contribute significantly to the ability of the bile canaliculus as a whole to bear pressure [1]. Here, we use lightsheet microscopy to discover that bulkheads are also dynamic, forming and retracting on a timescale of 20 min. We investigate the mechanical origins of this process by constructing a mechanical model balancing pressure and anisotropic surface tensions and spontaneous curvature of the apical cortices. We discuss the cell biological origins of these mechanical ingredients, the experimental evidence for them, and their role in bulkhead formation.
[1] Bebelman, M. P., Bovyn, M. J., et al. Hepatocyte apical bulkheads provide a mechanical means to oppose bile pressure. J. Cell Biol. 222, e202208002 (2023).
Keywords: lumen mechanics; actomyosin cortex; liver development