New light on cellular hydration

Sylvie Roke, head of the Laboratory for Fundamental BioPhotonics © 2020 Alain Herzog/EPFL - Researchers from EPFL's Institute of Bioengineering and the University of Geneva have teamed up to develop new tools for studying water flow across cell membranes. Why do we get hangovers? "They're caused by a water imbalance within our bodies," says Sylvie Roke, the head of EPFL's Laboratory for Fundamental BioPhotonics. "Our cells become dehydrated as they eliminate alcohol through osmosis." This process takes place in our bodies every day without us even knowing. The wrinkles that appear in our fingers when we stay in the bathtub too long are another example - that's the result of water penetrating our body and then our cells. "Osmosis occurs when two liquids with different concentrations of a given solute come into contact through a semi-permeable membrane," says Aurélien Roux, a biochemistry professor at the University of Geneva. "The water passes from the lower-concentration liquid to the higher-concentration one, until an equilibrium is established between the two." It's all about tension Roke and Roux are studying the molecular mechanisms involved in cell membrane tension - still largely unknown on a nanometric and microscopic scale - in a project that has just received a Synergy Grant from the European Research Council. Osmosis takes place through our cell membranes because they're semi-permeable: they let water through but not ions.