Berlin 2015 – scientific programme
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BP: Fachverband Biologische Physik
BP 15: Posters: Multi-cellular systems
BP 15.2: Poster
Monday, March 16, 2015, 17:30–19:30, Poster A
Osmolarity mediated growth of MDCK model tissue — •Damir Vurnek1, Sara Kaliman1, Carina Wollnik2, Florian Rehfeldt2, and Ana-Sunčana Smith1 — 1Theoretical Physics I, FAU Erlangen — 23rd institute Phyiscs-Biophysics, Georg-August University, Göttingen
The capacity to adapt to changes in environmental osmotic conditions is vital for the functioning of epithelium. We study this response by growing MDCK II model tissues, mm2 to cm2 sized clusters, with increased concentrations of mannitol, urea or NaCl. The phase space of tissue viability is characterized from isotonic to elevated toxic conditions. In young colonies, elevated osmotic conditions suppress the growth. With increasing age, adaptation takes place, and the colony develops the same morphology as the controls, with the edge at low and the center at relatively high densities. We characterize the osmolyte/concentration specific proliferation rates, absolute colony sizes, as well as the steady state cell densities. Finally, the internal structure of the cells within the colony is addressed. Even in the intermediate stages of growth DNA damage is evident on the nuclei near the colony edge, however it lacks in the dense bulk of the tissue. Here, two factors could be intertwined. With densification, decreasing apical and basal surfaces expose less cell membrane to the hostile surrounding and/or the proliferating edge is more prone to damage during the cell cycle. As tissue reaches adaptation, high osmolarity brings added features to tissue cooperativity and nuclei elongations show differences in the stress forces for different applied osmolytes.