Question

During cell locomotion, an adherent cell generates tractional stresses at the cell-substrate interface. Recent quantitative measurements, however, showed that the magnitudes of the tractional stresses in several cell types are many folds higher than what is necessary to overcome the total viscous drags on the cell surface. What might be the other role(s) of generating such a large tractional stress in a moving cell? What generates the large tractional stresses in the cytoplasm of the cell?

Answer 1

Traction forces at extracellular adhesions are responsible for opposing cytoskeletal contractile forces. Cell mobility is essential for morphogenesis, wound healing, and immune response. According to a study, when adhesion to a substrate is strong then poor retraction and cell movement happen. According to the clutch hypothesis, slow-moving cells have high retrograde flow and hence produce less traction force but in fast moving cells, there is a large traction force due to low retrograde flow. There are some cells also that are slow moving but have a larger number of adhesions.

What generates the large tractional stresses in the cytoplasm of the cell?

• Increased matrix stiffness
• Increased Collagen density

Roles of large tractional stress in a moving cell

• It mediates normal cell migration
• Adhesion
• Proliferation
• Differentiation
• Mechanotransduction
• ECM remodeling.