Researchers at the University of Wisconsin–Madison and Northeastern University found that reducing cell-cell adhesion increases fluidity in epithelial cell monolayers without changing cell shape, according to a study published in Nature Communications.
Standard vertex models previously treated tissue fluidity in confluent epithelia as governed strictly by a geometric shape index, which was assumed to depend on the balance between cortical tension and intercellular adhesion.
The authors observed that lowering cell-cell adhesion increased fluidity while cell shape index, cell density, substrate traction, and junctional line tension remained unchanged. This decoupling showed that current vertex models, which treat adhesion solely as a factor in interfacial tension, do not fully capture epithelial mechanics.
The research team extended the theoretical framework to incorporate a dual role for adhesion. Their updated model includes both the thermodynamic property setting interfacial adhesion energy at cell junctions and the kinetic property producing viscous drag from the relative motion between adjacent cells. The formulation matched the experimental measurements, showing that dissipative friction and adhesive energy together govern tissue fluidity.
Pradip K. Bera, Molly McCord, and Jacob Notbohm of the University of Wisconsin–Madison conducted the study with Anh Q. Nguyen and Dapeng Bi of Northeastern University.
The National Science Foundation, the National Institutes of Health, the Sloan Research Fellowship, and the Human Frontier Science Program funded the research.
