Figure 7. Interaction of Aβ and TLR-3 stimulating ligand poly I:C on stimulation of human brain microglia.
(A). Real time PCR analyses showing effects of different Aβ and poly IC doses on stimulation of TLR-3 expression. Results show that Aβ doses did not significantly change TLR-3 mRNA expression in microglia (n=3), while different doses of poly I:C (pIC) had biphasic response. Low dose 0.25 μg/ml (PIC 0.25) significantly inhibited TLR-3 expression (p<0.01), middle dose (2.5 μg/ml) had no significant effect while highest dose (25 μg/ml) had significant stimulation.
B). Stimulation of IFN-β mRNA expression by poly I:C (2.5 μg/ml) was not modulated by Aβ (2 μM). Results show strong induction of IFN-β mRNA expression by poly I:C (2.5 μg/ml dose) in human microglia. There was no induction with Aβ (1 μM) treatment. Aβ treatment did not modulate effects of poly I:C.
(C and D). Poly I:C treatment of microglia stimulated expression of Aβ degrading enzyme neprilysin (MME) mRNA but not insulin degrading enzyme (IDE). Results show induction of neprilysin (MME) mRNA expression by poly I:C (2.5μg/ml dose) in human microglia, but there was no induction with Aβ (1 μM) treatment (D). Aβ treatment did not modulate effects of poly I:C. Poly I:C or Aβ did not significantly affect expression of insulin degrading enzyme (IDE).