Extended Data Fig. 3: VCAM1 regulates microglial amyloid-beta chemotaxis after interleukin-33 treatment.
From: The VCAM1–ApoE pathway directs microglial chemotaxis and alleviates Alzheimer’s disease pathology
a-c, Identification of a potential cell-surface receptor that controls the amyloid-beta (Aβ) chemotaxis of chemotactic microglia. a, Subcellular distribution of the 142 signature genes of chemotactic microglia. b, Gene Ontology (GO) analysis of the 39 chemotactic signature genes localized on the cell surface. FDR, false discovery rate. c, Functional classification of the 7 cell adhesion molecules. d-f, Neutralizing antibodies against ICAM1 and VCAM1 inhibit interleukin-33 (IL-33)–stimulated microglia migration in vitro. d,e, IL-33 promotes the migratory response of BV2 cells in a wound-healing assay (n = 3 from 3 independent batches; two-tailed unpaired Student’s t-test). f, Quantification showing the effects of CCR7-, ICAM1-, and VCAM1-neutralizing antibodies on the IL-33–stimulated migration of BV2 cells in a wound-healing assay (αCCR7 Con: n = 3; αCCR7 IL-33: n = 6; αICAM1 Con: n = 3; αICAM1 IL-33: n = 6; αVCAM1 Con: n = 5; αVCAM1 IL-33: n = 6; two-way ANOVA with Šidák’s multiple comparisons test). g-k, Neutralizing antibodies against CCR7, ICAM1, or isotype controls neither affect Aβ chemotaxis nor the induction of MHC-II+ microglia after IL-33 treatment.g,h, Representative images (g)and quantification (h) showing the proportions of Aβ plaque-associated microglia after administration of isotype control antibodies and IL-33 (IgG2a Con: n = 4; IgG2a IL-33: n = 4; IgG2b Con: n = 4; IgG2b IL-33: n = 4; IgG1 Con: n = 9; IgG1 IL-33: n = 8; two-way ANOVA with Šidák’s multiple comparisons test). i,j, Quantification showing the proportions of Aβ plaque-associated microglia (i) and the proportions of MHC-II+ microglia (j) after administration of neutralizing antibodies and IL-33 (IgG Con: n = 9; IgG IL-33: n = 8 for panel i and 7 for panel j; αCCR7 IL-33: n = 8; αICAM1 IL-33: n = 7; one-way ANOVA with Šidák’s multiple comparisons test). Scale bar = 20 μm. k,l, Long-term genetic ablation of microglial VCAM1 does not affect the survival of mice or the number of microglia. k, Survival curve of VCAM1-icKO mice 1 month after tamoxifen injection (n = 3 per condition). l, Quantification showing the number of microglia in VCAM1-icKO mice (n = 3 per condition; two-tailed unpaired Student’s t-test). m, Genetic ablation of microglial VCAM1 abolishes IL-33–induced Vcam1 expression in microglia (wild-type [WT] Con: n = 3; WT IL-33: n = 3; icKO Con: n = 3; icKO IL-33: n = 3; two-way ANOVA with Šidák’s multiple comparisons test). n, Genetic ablation of microglial VCAM1 inhibits microglial migration toward Aβ plaques after IL-33 treatment. Quantification showing the proportions of Aβ plaque-associated microglia in VCAM1-icKO mice after IL-33 treatment (WT Con: n = 11; WT IL-33: n = 12; icKO Con: n = 11; icKO IL-33: n = 13; two-way ANOVA with Šidák’s multiple comparisons test). All data are mean ± s.e.m.
