Prostaglandin E2 suppresses β1-integrin expression via E-prostanoid receptor in human monocytes/macrophages

β1-Integrins mediate cell attachment to different extracellular matrix proteins, intracellular proteins, and intercellular adhesions. Recently, it has been reported that prostaglandin E2 (PGE2) has anti-inflammatory properties such as inhibition of the expression of adhesion molecules or production of chemokines. However, the effect of PGE2 on the expression of β1-integrin remains unknown. In this study, we investigated the effects of PGE2 on the expression of β1-integrin in the human monocytic cell line THP-1 and in CD14+ monocytes/macrophages in human peripheral blood. For this, we examined the role of four subtypes of PGE2 receptors and E-prostanoid (EP) receptors on PGE2-mediated inhibition. We found that PGE2 significantly inhibited the expression of β1-integrin, mainly through EP4 receptors in THP-1 cells and CD14+ monocytes/macrophages in human peripheral blood. We suggest that PGE2 has anti-inflammatory effects, leading to the inhibited expression of β1-integrin in human monocytes/macrophages, and that the EP4 receptor may play an important role in PGE2-mediated inhibition.