PEA inhibits astroglial proliferation and reduces neuronal loss in mixed neuroglia co-cultures exposed to Aβ. Aβ-challenged (1 μg/ml) astrocyte/neuron mixed cultures were treated with PEA (0.1 μM) in the presence of the selective PPARγ antagonist (GW9662, 9 nM) or the selective PPARα antagonist (MK886, 3 μM). After 24 hours of treatment, cells were processed for analyses. (A) Immunofluorescence photomicrographs showing the effect of the treatments on astrocyte proliferation and neuronal loss, as determined by immunostaining for GFAP (green) and MAP2 (red), respectively. Arrows indicate chromatin condensation in nuclei stained with Hoechst dye (blue) as markers of apoptotic events. Scale bar: 10 μm. (B) Relative quantification of GFAP-positive cell number as a count of astrocyte proliferation. (C) Apoptotic events detected on MAP2-expressing cells as an indication of neuronal death. For (B) and (C), the average value was determined by counting cells in at least nine microscopic fields for each treatment. Results are presented as means ± SEM of three separate experiments. Statistical analysis was performed using parametric one-way analysis of variance, and multiple comparisons were performed using the Bonferroni test. ***P < 0.001 vs. unstimulated cells, ∘∘
P < 0.01 and ∘
P < 0.05 vs. Aβ-stimulated cultures.