Fig. 8. Regulation of adhesion dynamics in dendritic cells by PGE₂. PGE₂ signalling, mediated by EP2 and EP4 receptors, leads to elevation of the level of cAMP, activation of RhoA and inactivation of Rac1. PGE₂-mediated activation of RhoA promotes Rho-kinase activity and, subsequently, myosin-II-dependent contraction, leading to podosome dissolution and FA formation. By contrast, pathways leading to activation of Rac1 are known to promote podosome formation and induce cytoskeletal relaxation accompanied by a loss of FAs.