Western blotting analysis was performed as described previously (45 (link)). The following antibodies were used: mouse monoclonal anti-6E10 (recognizes Aβ and sAPPα; SIG-39320, Covance), rabbit polyclonal anti-Iba1 (019-19741, Wako), rabbit polyclonal anti-GFAP (Z0334, Dako), rabbit polyclonal anti-APP (recognizes APPfl, CTFα, and CTFβ; #2452, Cell Signaling Technology, Cambridge, MA, USA), rabbit monoclonal anti-nicastrin (#5887, Cell Signaling Technology), rabbit monoclonal anti-PEN2 (#5887, Cell Signaling Technology), rabbit monoclonal anti-PS2 (#5887, Cell Signaling Technology), rabbit monoclonal anti-BACE (#5606, Cell Signaling Technology), sheep polyclonal anti-Trem2 (AF1729, R&D Systems, Minneapolis, MN, USA), mouse polyclonal anti-GPR34 (ab169455, Abcam, Cambridge, MA, USA), mouse monoclonal anti-MerTK (#9178S, Cell Signaling Technology), goat polyclonal anti-P2Y6 (Sc-15217, Santa Cruz Biotechnology, Santa Cruz, CA, USA), and mouse monoclonal anti–β-actin (66009-1-lg, Proteintech, Wuhan, China).