Figure 6.

Effect of endothelial-cell-derived PDGF-B on BMSC differentiation in bone

(A) Scheme of tamoxifen-inducible PDGFB overexpression in ECs with Cdh5-Cre-ERT2 mice.

(B) Representative confocal image of 3-week-old control and R26-PDGFB^iEC femoral EMCN⁺ (red) blood vessels associated with PDGFRβ⁺ (green) BMSCs (arrowheads). Length of metaphyseal vessel columns (indicated by dashed lines) is increased in R26-PDGFB^iEC bone (n = 4; data are presented as mean ± SEM, p values, two-tailed unpaired t test).

(C) Expansion of EMCN^high (red) CD31^high (green) vessels (indicated by dashed lines) and increase of arterioles (arrowheads) in R26-PDGFB^iEC bone (n = 4; data are presented as mean ± SEM, p values, two-tailed unpaired t test).

(D) Confocal image and quantitation showing increase of OSX⁺ (green) cells in PDGFB^iEC bone (n = 4; data are presented as mean ± SEM, p values, two-tailed unpaired t test).

(E) Tamoxifen-inducible overexpression of human PDGF-B (PDGFB) in ECs.

(F and G) Representative confocal images and quantitative analysis of 8-week-old R26-PDGFB^iEC femur showing increase in PDGFRβ⁺ mpMSCs (F), arrowheads) and arterioles (G), arrowheads) relative to control (n = 4; data are presented as mean ± SEM, p values, two-tailed unpaired t test).

(H and I) Representative confocal images showing increased OSX⁺ cells (H) and decrease of PLIN⁺ adipocytes (arrowheads) (I) in 8-week-old R26-PDGFB^iEC femur relative to control (n = 4; data are presented as mean ± SEM, p values, two-tailed unpaired t test).

See also Figures S7 and S8