MMP9 and Alzheimer disease: In conclusion, our results suggest that Lpc-EV has the ability to induce MeCP2- and Sirt1-dependent upregulation of Bdnf, Nt3, Nt4/5, TrkB, Mmp-2 and Mmp-9, and epigenetic modification is a critical mechanism by which Lpc-EV alleviates AD-like pathology in Tg-APP/PS1 mice.