ono-ae-248 and Necrosis

To investigate the effect of EP(3) agonist--ONO-AE-248 on neutrophils.. Electron microscopy, MTS assay, RT-PCR and FACS were used to observe the morphology, viability, EP(3) receptor expression and apoptosis of neutrophils treated with ONO-AE-248.. EP(3) receptor was expressed on neutrophils. ONO-AE-248 rapidly caused a unique form of neutrophil death, showing morphological changes of nucleus, including fusion of the lobules, blebbing and rupture of the nuclear membrane, which were different from typical morphological changes of apoptosis and necrosis. The death was dependent on ATP.. The death of neutrophils caused by ONO-AE-248 is likely to be one of the forms of "non-apoptotic programmed cell death".

Topics: Apoptosis; Cell Death; Cells, Cultured; Dinoprostone; Flow Cytometry; Humans; Microscopy, Electron, Transmission; Necrosis; Neutrophils; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP3 Subtype; Reverse Transcriptase Polymerase Chain Reaction

An increase of intracellular cAMP mediated by prostaglandin E2 (PGE2) has been shown to delay spontaneous apoptosis of neutrophils. It has been demonstrated that a selective agonist for PGE2 receptor subtype 3 (the EP3 receptor) is capable of decreasing cAMP and stimulating phosphoinositide turnover in various types of cells. We investigated the effect of a selective EP3 receptor agonist, ONO-AE-248, on neutrophil viability. ONO-AE-248 rapidly caused a unique form of neutrophil death. The agonist primarily induced morphological changes of the nucleus, including fusion of the lobules, decreased compactness of the chromatin, and blebbing and rupture of the nuclear membrane. This was followed by an increase of plasma membrane permeability and cell lysis. During these processes, neither apoptotic changes such as nuclear condensation, DNA fragmentation, and expression of phospholipid phosphatidylserine on the plasma membrane nor necrotic changes such as chromatin clumping and organelle destruction were apparent in the treated neutrophils. The fatal effect of the agonist night be specific for neutrophils because it failed to promote the rapid death of other types of cells. Although activation of neutrophils by ONO-AE-248 was not evident, experiments using metabolic inhibitors demonstrated that the agonist caused neutrophil death via the activation of protein kinase C in the presence of intracellular ATP. These findings indicated that EP3 receptor-mediated signals might promote a novel form of neutrophil death, which differs from typical apoptosis or necrosis.

Topics: Apoptosis; Cell Death; Cells, Cultured; Dinoprostone; Humans; Necrosis; Neutrophils; Receptors, Prostaglandin E