Quantitative Phase Imaging of Spreading Fibroblasts Identifies the Role of Focal Adhesion Kinase in the Stabilization of the Cell Rear

0533929 - MBÚ 2021 RIV CH eng J - Journal Article
Ramaniuk, Olga - Klímová, Zuzana - Groušl, Tomáš - Vomastek, Tomáš
Quantitative Phase Imaging of Spreading Fibroblasts Identifies the Role of Focal Adhesion Kinase in the Stabilization of the Cell Rear.
Biomolecules. Roč. 10, č. 8 (2020), č. článku 1089. E-ISSN 2218-273X
R&D Projects: GA ČR(CZ) GJ19-07603Y; GA ČR GA18-11908S; GA MŠMT(CZ) LM2018129
Institutional support: RVO:61388971
Keywords : coherence-controlled holographic microscopy * quantitative phase imaging * cell dry mass
OECD category: Microbiology
Impact factor: 4.879, year: 2020
Method of publishing: Open access
https://www.mdpi.com/2218-273X/10/8/1089

Cells attaching to the extracellular matrix spontaneously acquire front-rear polarity. This self-organization process comprises spatial activation of polarity signaling networks and the establishment of a protruding cell front and a non-protruding cell rear. Cell polarization also involves the reorganization of cell mass, notably the nucleus that is positioned at the cell rear. It remains unclear, however, how these processes are regulated. Here, using coherence-controlled holographic microscopy (CCHM) for non-invasive live-cell quantitative phase imaging (QPI), we examined the role of the focal adhesion kinase (FAK) and its interacting partner Rack1 in dry mass distribution in spreading Rat2 fibroblasts. We found that FAK-depleted cells adopt an elongated, bipolar phenotype with a high central body mass that gradually decreases toward the ends of the elongated processes. Further characterization of spreading cells showed that FAK-depleted cells are incapable of forming a stable rear, rather, they form two distally positioned protruding regions. Continuous protrusions at opposite sides results in an elongated cell shape. In contrast, Rack1-depleted cells are round and large with the cell mass sharply dropping from the nuclear area towards the basal side. We propose that FAK and Rack1 act differently yet coordinately to establish front-rear polarity in spreading cells.
Permanent Link: http://hdl.handle.net/11104/0312155