Figure 4.

Identification of Apln⁺ ECs in Adult BM

(A) Confocal tile scan images (left) showing distribution of GFP⁺ cells in Apln-mTmG mice. High magnifications (right) show enlarged regions of the metaphysis and diaphysis. Arrows mark GFP⁺ cells in endosteum.

(B and C) Emcn and CD31 (B) and VEGFR2 and VEGFR3 (C) staining in adult Apln-mTmG femur. Arrows mark GFP⁺ ECs.

(D) FACS plots of GFP⁺ cells isolated from Apln-mTmG mice.

(E) Histogram of Emcn expression in GFP^– and GFP⁺ cells. Quantification of mean fluorescence intensity (MFI) in GFP^– and GFP⁺ cells (n = 3 per group). Error bars, mean ± SEM. p values, two-tailed unpaired Students’ t test.

(F) CD150⁺ Lin^– CD48^– HSC (arrow) and GFP⁺ EC in the metaphysis and metaphysis-diaphysis transition area of Apln-mTmG mice.

(G) Distribution of distance between DAPI⁺ cells (n = 3,872) or CD150⁺ Lin^– CD48^– HSCs (n = 52) and GFP⁺ ECs cells in the metaphysis and metaphysis-diaphysis transition area of Apln-mTmG mice.

(H) PCA plot of total BM cells (BMC), Apln⁺ ECs (from whole bone), and diaphyseal ECs (DP ECs).

(I) MA plot showing differentially expressed genes between Apln⁺ ECs and DP ECs.

(J) Top 15 enriched pathways in GO analysis in Apln⁺ ECs relative to DP ECs.

(K) Heatmap of selected genes in Apln⁺ ECs.

See also Figure S4.