Figure 4. The effects of PD98059 and geldanamycin on CB2 receptor-mediated actin cytoskeleton changes in trabecular meshwork cells. Intact trabecular meshwork (TM) cells were plated on fibronectin-coated (5 μg/ml) coverslips and grown to confluence. Serum-deprived TM cells were pretreated with vehicle (A and B), 30 μM PD98059 (C and D) for 30 min and 10 μM geldanamycin (GA; E and F) for 2 h. Subsequently, the TM cells were treated for 3 h with vehicle (A), 100 nM JWH015 (B), 30 μM PD98059 (C), 100 nM JWH015 plus 30 μM PD98059 (D), 10 μM geldanamycin (E), and 100 nM JWH015 plus 10 μM geldanamycin (F). The TM cells were then fixed with paraformaldehyde and stained with Alexafluor 488-labeled phalloidin as detailed in the Methods section. JWH015 caused a significant decrease in staining for actin stress fibers, compared with vehicle control. PD98059 as well as geldanamycin pretreatment blocked the changes brought about by JWH015.