Effect of Prostaglandin E Receptor Subtype EP4 Selective Agonist on the Secretion of Tumor Necrosis Factor-alpha by Macrophages in Acute Ethanol-Loaded Rats

Background It is suggested that endotoxin and proinflammatory cytokines play an important role in the development and progression of alcoholic liver disease. Recently, a prostaglandin receptor subtype EP4 agonist with cytoprotective effect has been developed. We examined the efficacy of an EP4 agonist ONO-AE1-437 on tumor necrosis factor-alpha (TNF-alpha) secretion of Kupffer cells, splenic macrophages, and alveolar macrophages in acute ethanol-loaded rats. Methods Kupffer cells, splenic macrophages, and alveolar macrophages were isolated from control and acute ethanol-loaded rats (5 mg/g body weight of ethanol, intraperitoneally). After the preculture in the medium that containing 0, 0.1, 1, 10, or 100 nmol/liter of ONO-AE1-437, TNF-alpha secretion of these cells stimulated by 100 ng/ml of endotoxin was determined for 3 hr. Results The amount of TNF-alpha secreted from alveolar macrophages was largest in both the control and the acute ethanol-loaded rats. Acute ethanol load enhances TNF-alpha secretion of splenic macrophages. The addition of ONO-AE1-437 significantly inhibited TNF-alpha secretion of Kupffer cells and splenic macrophages in both the control and the acute ethanol-loaded rats. Alveolar macrophages were less affected. Conclusions An EP4 agonist ONO-AE1-437 suppresses excess TNF-alpha secretion from macrophages and seems promising for future trial in patients with severe alcoholic hepatitis.