Assay of Hydroxyproline (Hyp), GAG and Calcium (Ca) in ECMs. The mechanical strain increased Hyp content, and relative levels of GAG and Ca (the first and second column of A, B and C). Integrin-β1 siRNA reduced the content of Hyp, levels of GAG and Ca, which increased by the tensile strain. The effect of integrin-β5 siRNA on levels of hyp, GAG and Ca was nearly naught, the inhibitory effect of both integrin-β1 siRNA and integrin-β5 siRNA simultaneously on hyp, GAG, Ca was weaker than only integrin-β1 siRNA. *P < 0.05, **P < 0.01, between indicated groups.