Fibroblast traction as a mechanism for collagen morphogenesis

Abstract

Tissue culture on thin layers of silicone rubber was used to compare the forces exerted by various differentiated cell types, and the effects of cellular traction on re-precipitated collagen matrices were examined. The strength of cellular traction differs greatly between cell types and this traction is paradoxically weakest in the most mobile and invasive cells (leukocytes and nerve growth cones). Untransformed fibroblasts exert forces very much larger than those actually needed for locomotion. This strong traction distorts collagen gels dramatically, creating patterns similar to tendons and organ capsules. This morphogenetic rearrangement of extracellular matrices is probably the primary function of fibroblast traction and explains its excessive strength. The strongest traction was exerted by fibroblasts from embryonic chick heart, skeletal muscle and tendon, dermis and the choroid coat of the eye, and by BALB/3T3 mouse cells.