RhoA pathway inhibitor Y-27632 abrogates macrophage polarization and podosome formation. The unpublished data from our laboratory show that Y-27632 inhibitor prevents actin-dependent polarization of macrophage morphology and formation of actin-containing podosome rosette. (a) Mouse control macrophage shows highly elongated and polarized phenotype and the podosomes clustered into the rosette. (b) Macrophage incubated in the presence of Y-27632 inhibitor does not polarize and shows low number of dispersed podosomes. Actin was stained red with rhodamine-conjugated phalloidin. Yellow tint of podosome rosette in the control macrophage image results from the overexposure of highly concentrated actin in the podosomes.