Cell
response to substrate rigidity, closely related to extracellular
matrix protein composition, requires actomyosin-generated contractility.
By introducing coefficients describing cell spreading and traction
dynamics, and a revised high-resolution traction force microscopy,
we analyzed the static and dynamic features of fibroblasts on fibronectin-
or collagen- coated stiff or soft substrates. Large cell spreading
area and branchlike morphology were more favorable on fibronectin
than collagen. Cell spreading on fibronectin-coated substrates was
more sensitive to rigidity compared with collagen. Low concentration
fibronectin-coated substrate induced more dynamic lamellipodia movement
than other conditions. Interestingly, the static average cell traction
on high concentration fibronectin-coated stiff and soft substrates
showed no difference. However, the lamellipodium traction dynamics
was sensitive to rigidity on fibronectin. Particularly, lamellipodia
on fibronectin-coated soft substrate performed much higher local traction
dynamics compared with other groups. Together, dynamics of cell adhesion
and traction are regulated by extracellular matrix protein composition,
coupled with substrate rigidity