Antagonism of neuronal prostaglandin E(2) receptor subtype 1 mitigates amyloid ß neurotoxicity in vitro.

ABSTRACT

Multiple lines of evidence indicate that regional brain eicosanoid signaling is important in initiation and progression of neurodegenerative conditions that have neuroinflammatory pathologic component, such as AD. We hypothesized that PGE(2) receptor subtype 1 (EP1) signaling (linked to intracellular Ca(2+) release) regulates Aß peptide neurotoxicity and tested this in two complementary in vitro models a human neuroblastoma cell line (MC65) producing Aß(1-40) through conditional expression of the APP C-terminal portion, and murine primary cortical neuron cultures exposed to Aß(1-42). In MC65 cells, EP1 receptor antagonist SC-51089 reduced Aß neurotoxicity ~50 % without altering high molecular weight Aß immunoreactive species formation. Inositol-3-phosphate receptor antagonist 2-aminoethoxy-diphenyl borate offered similar protection. SC-51089 largely protected the neuron cultures from synthetic Aß(1-42) neurotoxicity. Nimodipine, a Ca(2+) channel blocker, was completely neuroprotective in both models. Based on these data, we conclude that suppressing neuronal EP1 signaling may represent a promising therapeutic approach to ameliorate Aß peptide neurotoxicity.