Activation of α7 Nicotinic Acetylcholine Receptor by its Selective Agonist Improved Learning and Memory of Amyloid Precursor Protein/Presenilin 1 (APP/PS1) Mice via the Nrf2/HO-1 Pathway

BACKGROUND:To reveal the mechanism underlying the effect of α7 nicotinic acetylcholine receptor (nAChR) on neurodegeneration in Alzheimer disease (AD), the influence of the receptor on recognition in APP/PS1 mice was evaluated by using its selective agonist (PNU-282987). MATERIAL AND METHODS:APP/PS1 and wild-type (WT) mice were treated with PNU or saline, respectively, for 7 days at the ages of 6 and 10 months. RESULTS:Morris water maze analysis showed that both at 6 and 10 months of age, PNU treatment enhanced the learning and memory of APP/PS1 mice. However, PNU treatment did not alter the number of senile plaques. Furthermore, a higher protein expression of Nrf2/HO-1, ADAM10, SYP, and SNAP-25, and a lower level of oxidative stress, were observed in the hippocampus of APP/PS1 mice treated with PNU compared with the control group. CONCLUSIONS:The results indicated that the activation of α7 nAChR by PNU improved the learning and memory of mice carrying the APP/PS1 mutation, regulated the levels of enzymes that mediate APP metabolization to reduce β-amyloid peptide damage, and decreased the level of oxidative stress and maintained synaptic plasticity, in which the mechanism might be enhancement of the Nrf2/HO-1 pathway.