Authors: Jinyu Fu et al.

Journal: bioRxiv (2024)

Institution: Department of Physics and Astronomy, Johns Hopkins University. Baltimore MD

Research Areas: Cell Biology

Cell Lines: NIH3T3, HT1080, T47D, Hs578, RPE 2n, RPE 4n, MCF-10A, MDA-MB-231, and its single cell clones (SCCs) MDA-SCC-1006, MDA-SCC-1304, and MDA-SCC-1308

Summary: A cell’s global physical state is characterized by its volume and dry mass. The ratio of cell mass to volume is the cell mass density (CMD). Using the Fluorescence eXclusion method (FXm) and Quantitative Phase Microscopy (QPM), we investigated dynamics after exposure to sudden media osmolarity change. We find that while the cell volume and mass exhibit complex behavior after osmotic shock, CMD follows a straightforward monotonic recovery in 48 hours. The recovery is cell-cycle independent and relies on a coordinated adjustment of protein synthesis and volume growth rates. Taken together, we reveal that cells possess a robust control system that actively regulates CMD during environmental change. HoloMonitor morphology data was used to calculate CMD in response to osmotic changes.

Keywords: cell mass density, macromolecular crowding, cell regulation, osmolarity, environmental stress, fluorescence eXclusion method, quantitative phase microscopy