Fig. 5

PEA fails to counteract submucosal plexus-EGC activation induced by HIV-1 Tat in PPARα^−/− mice. EMSA analysis showed marked upregulation of NF-kappaB in submucosal plexi at day 7 following HIV-1 Tat administration, compared to vehicle group. PEA was ineffective to reduce NF-kappaB activation in PPARα^−/− mice, while bisacodyl (20 mg/kg) did not induce NF-kappaB upregulation. a Representative NF-kappaB activation complex bands and b their densitometric quantification (OD = optical density in mm²). HIV-1 Tat significantly increased GFAP, S100B, TLR4, and iNOS protein expression and S100B and NO₂⁻ levels in submucosal plexi isolated from PPARα^−/− mice in the same experimental conditions. Again, HIV-1 Tat-mediated effects were unaffected by PEA, while bisacodyl did not induce any change in the above investigated parameters. c Representative immunoreactive bands of analyzed proteins, d–g their respective densitometric quantification (normalized against the expression of the housekeeping protein β-actin; OD = optical densitometry in mm²) and h, i S100B and NO₂⁻ levels. Immunofluorescence analysis showed an increased S100B/iNOS co-expression in submucosal plexus-EGCs at day 7 after HIV-1 Tat administration, vs. vehicle group. As expected, PEA was unable to counteract HIV-1 Tat activity and bisacodyl did not induce any S100B/iNOS upregulation. l S100B (red) and iNOS (green) immunoreactivity with m the respective quantification of S100B (open bars) and iNOS (filled bars) expression in the submucosal plexi. n HIV-1 Tat caused a marked increase of endogenous PEA content in submucosal plexi vs. vehicle group. Lidocaine inhibited HIV-1 Tat activity, whereas bisacodyl did not produce any alteration in endogenous PEA production. The results are expressed as mean ± SEM of n = 5 experiments. **p < 0.01 and ***p < 0.001 vs. vehicle group; °°p < 0.01 and °°°p < 0.001 vs. HIV-1 Tat group. Scale bar = 100 μm