Anatomical and functional relationships between mononuclear phagocytes and Nestin+ niche cells. (A) Distribution of BM CD68+ (white) and CD169+ (red) cells in 5-µm femoral sections of Nes-GFP mice. Dashed line demarcates separation of bone and BM. Images were acquired at 40× magnification (bar, 20 µm). Isotype control is shown in inset. (B–E) Relative expression of Cxcl12 (B), Angpt1 (C), Kitl (D), and Vcam1 (E) in CD45− Ter119− Nestin+ (Nestin+) and CD45− Ter119− Nestin (Nestin−) fractions sorted from the BM and osteoblasts sorted from the bone 14 h after treatment with PBS- (blue bars) or clodronate-encapsulated (red bars) liposomes. Data are presented with the mean expression of the PBS liposome-treated Nestin+ fraction set at 100% and are representative of three independent experiments (n = 4–5). Data analyzed by one-way ANOVA/Newman-Keuls test. ***, P < 0.001.