Deletion of microsomal prostaglandin E synthase-1 protects neuronal cells from cytotoxic effects of β-amyloid peptide fragment 31–35

Epidemiological studies have suggested that the long-term use of nonsteroidal anti-inflammatory drugs that inhibit cyclooxygenase (COX) activity moderates the onset or progression of Alzheimer’s disease (AD). Thus it has been suggested that prostaglandin E2 (PGE2), a major end-product of COX, may play a pathogenic role in AD, but the involvement of PGE synthase (PGES), a terminal enzyme downstream from COX, has not been fully elucidated. To examine the involvement in AD pathology of microsomal PGES-1 (mPGES-1), a PGES enzyme, we here prepared primary cerebral neuronal cells from the cerebri of wild-type and mPGES-1-deficient mice and then treated them with β-amyloid (Aβ) fragment 31–35 (Aβ31–35), which represents the shortest sequence of native Aβ peptide required for neurotoxicity. Treatment of wild-type neuronal cells with Aβ31–35 induced mPGES-1 gene expression and PGE2 production, followed by significant apoptotic cell death, but apoptosis was not induced in mPGES-1-deficient cells. Furthermore, the combined treatment of Aβ31–35 and PGE2 induced apoptosis in mPGES-1-deficient neuronal cells. These results indicated that mPGES-1 is induced during Aβ-mediated neuronal cell death and is involved in Aβ-induced neurotoxicity associated with AD pathology.