APP and Alzheimer disease: The aim of the present study is to investigate the expression and distribution of MEF2C and Aβ in the brain of AD patients and APP/PS1_DT mice, and to investigate the effects of MEF2C on reducing the production and aggregation of Aβ, relieving the neurotoxic effects of Aβ, and improving the learning and memory abilities of APP/PS1_DT mice by regulating the Nrf2-ARE signal pathway.