Figure 2.

GGT5 expression is downregulated in Aβ _1–42 –treated hCMEC/D3 and bEnd.3 cells and in the brains of APP/PS1 mice.

(A) mRNA-seq analysis of hCMEC/D3 cells identified 178 genes that were differentially expressed between the vehicle and Aβ_1–42 intervention groups. (B) Nine downregulated genes and two upregulated genes were selected by comparing the 178 differentially expressed genes with an existing AD single-cell sequencing database. (C) qPCR verification of the expression levels of the 11 selected genes (n = 3 per group). (D, E) Representative western blots (D) and quantitative analysis (E) of AGRN, LRP1, and GGT5 expression in hCMEC/D3 cells treated with vehicle or Aβ_1–42 (each row is an image from a different blot) (n = 3–4 per group). (F, G) Representative western blots (F) and quantitative analysis (G) of GGT5 expression in bEnd.3 cells treated with vehicle or Aβ_1–42 (n = 4 per group). (H–K) Representative western blots of GGT5 and Aβ in the Ctx (H) and Hip (I) and quantitative analysis of GGT5 (J) and Aβ (K) expression in the Ctx and Hip of mice (n = 4 per group). Data are expressed as mean ± SEM. *P < 0.05, ***P < 0.001 (one-way analysis of variance followed by Tukey’s post hoc test [J and K], or independent-samples t-test [C, E and G]). AD: Alzheimer’s disease; AGRN: Agrin; ARHGEF17: Rho guanine nucleotide exchange factor (GEF) 17; Aβ: amyloid-β; Ctx: cortex; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GGT5: gamma-glutamyltransferase 5; Hip: hippocampus; LRP1: low density lipoprotein receptor related protein 1; MCAM: melanoma cell adhesion molecule; MRC2: mannose receptor c type 2; PLOD1: procollagen lysine-1,2-oxoglutarate-5-dioxygenase 1; RPS27A: ribosomal protein S27A; WT: wide type.