Expression of prostaglandin E2 synthases in mouse postnatal cortical neurons

Eicosanoids and the enzymes associated with their metabolism play an active role in the neuroinflammatory process that is often a hallmark of neurodegenerative disorders. Cerebral cortical neurons constitute a highly affected cell population in neurologic disorders. To obtain a cellular model to analyze prostaglandin action and metabolism in cortical neurons, we developed postnatal neuronal cultures from mouse cortex in a serum-free medium. Cultured cortical cells were highly enriched in neurons containing only 5 +/- 2% glial cells. The cultures were assayed for expression of several protein markers of neuronal maturity: synaptic markers (synapsin I and synaptophysin) and glutamate receptor subunits (NMDA receptor 1 and glutamate receptor 1). The protein expression of eicosanoid-metabolizing enzymes, including cyclooxygenase-2 and microsomal and cytosolic PGE2 synthases, was investigated as well. Postnatal neurons successfully survived for a long term (up to 40 days) in vitro in serum-free media, as characterized by the expression of synapsin I, synaptophysin, and microtubule-associated protein 2. Glutamate receptor subunit expression increased over time in cultures, with the highest levels at 15 days. Enzymes involved in the eicosanoid metabolism followed a distinct pattern of expression, suggesting potential regulation of PGE2 synthesis with time in cultures under basal conditions. Use of postnatal brain cultures offers several advantages, especially regarding degree of neuronal maturation, use of postnatal pups instead of pregnant mice, and potentially increased clinical relevance in models of neuroinflammation processes and prostanoid cellular neurobiology.