Objective      To investigate the effects of substrate stiffness on the stability of adhesion complexes of confluent hepatic (L02) cells cultured on substrates with different stiffness (3.6

10

and 30 kPa) .       Methods      Real-time photomicrography was applied to record the morphology of L02 cells. Immunofluorescence staining was used to test the distribution of F-actin and β-catenin. Western blotting was applied to detect the expression of β-catenin and its phosphorylation.       Results      Adhesion complexes of confluent L02 cells exhibited differ

ent stability when these cells were cultured on substrates with different stiffness. When treated with EDTA

L02 cells on rigid substrate separated more quickly than those on soft substrate. F-actin of confluent L02 cells formed a ring-like conformation under the cortical

and β-catenin located at the cell-cell contact sites on soft substrate. With the increase of substrate stiffness

the ring-like cytoskeleton reduced and more F-actin distributed in cytoplasm

and β-catenin exhibited a similar distribution. As the substrate stiffness increased

the expression of β-catenin on membrane decreased (

P

0.01) while that of phosphorylated β-catenin (p-β-catenin

Tyr654) in cytoplasm increased significantly (

P

0.01).       Conclusion      Substrate stiffness affects the stability of adhesion complexes of confluent L02 cells observably. The cells on rigid substrate show weaker adhesion

which may be induced by up-regulation of p-β-catenin (Tyr654) expression.