Fig. 9. Rac inhibition reduces integrin β1 expression in PKC^+/+ fibroblasts. (A) As described in the Materials and Methods, western blot analysis was used to detect integrin β1 expression in PKC^+/+ and PKC^-/- fibroblasts. Cells were incubated in the presence or absence of the Rac inhibitor NSC23766 (100 µM, 1 hour). Rac inhibition reduced integrin β1 expression in PKC^+/+, but not in PKC^-/-, cells, indicating Rac operates upstream of integrin β1 expression and, in this context, in a PKC-dependent fashion. Rac inhibition also reduced -SMA protein expression in PKC^+/+, but not PKC^-/-, cells. (B) As described in the Materials and Methods, a floating collagen gel contraction assay was used to detect ECM contraction by PKC^+/+ and PKC^-/- fibroblasts over a 24-hour period. Cells were incubated in the presence or absence of the Rac inhibitor NSC23766 (100 µM). Contraction was observed only in untreated PKC^+/+ cells (^*P<0.05). (C) As described in the Materials and Methods, a cell migration assay was performed on PKC^+/+ and PKC^-/- fibroblasts over a 72-hour period in the presence or absence of the Rac inhibitor NSC23766 (100 µM). Gap size expressed as a percentage of the original wound is shown (average±s.d.). The presence of the Rac inhibitor reduced migration of PKC^+/+ cells (^*P<0.05).