Immunofluorescence Staining of Brain and Cell Samples

Immunofluorescence staining was performed according to our previously published protocols [41 (link), 42 (link)]. Briefly, the brain sections (6 μm thick) were incubated with primary antibodies against ALX/FPR2 (1:200, cat. no. ab203129, Abcam), GFAP (1:200, cat. no. MAB3402X, EMD Millipore, USA), Iba-1 (1:200, RRID: AB_2224402), and NeuN (1:200, cat. no. ABN78A4, EMD Millipore, USA) overnight at 4 °C. Then, the brain sections were incubated with the corresponding secondary antibodies conjugated with Alexa Fluor 488 and/or Alexa Fluor 594 (Jackson ImmunoResearch Incorporation, West Grove, PA, USA) for 1 h at room temperature, after which a ZEISS HB050 inverted microscope system was used for fluorescence detection.
For in vitro cell staining, primary antibodies against Iba-1 (1:200, RRID: AB_2224402) and p65 (1:200, 1:1000, cat. no. D14E12, CST) were used for microglia staining, while a primary antibody against MAP2 (1:500, cat. no. ab183830, Abcam) was used to stain neurons. The protocols and the secondary antibodies used for in vitro cell staining were the same as those used to stain brain sections.