Figure 1.

Simvastatin treatment increases active RhoA in D1 cells. Simvastatin constitutively activated RhoA, 0.5–24 hours after treatment.

Notes: Peak activity was reached at 3 hours (A), with RhoA activity increasing in a dose-dependent manner (B), as determined using Western blots of immunoprecipitates. Simvastatin dose-dependently increased RhoA protein levels in the cytosol (aqueous phase) and reduced RhoA content in the membrane (detergent phase) at 3 hours (C). The amount of RhoA that coimmunoprecipitated with RhoGDIα was proportional to the amount of RhoGDIα in the lysate, because simvastatin treatment reduced RhoGDIα-associated RhoA at 3 hours (D). Simvastatin enhanced the ROCK substrate of phospho-MYPT (E) and pMLC (F) at 3 hours. The results are the mean values of three independent measurements, error bars: SEM. *P<0.05; **P<0.01 vs control; ^#P<0.05, ^##P<0.01 vs SIM (1 µm).

Abbreviations: SIM, simvastatin; ROCK, Rho-associated protein kinase; SEM, standard error of the mean; pMLC, phosphomyosin light chain; IP, immunoprecipitation.