Fig 9. M-CSF_RGD proteins inhibit bone resorption in ovariectomized mice.

(A) Ex vivo images of 12-weeks-old WT C57BL6 mice organs. The organs were removed and imaged 1.5 h and 3 h after mice were injected s.c. and compared with organs of a mouse that had been injected with unconjugated dye and of a mouse that had not been injected with the proteins (right). To determine whether M-CSF_RGD variant 5.6 accumulates in the bones, the epiphysis and diaphysis of the femur of a mouse injected with variant 5.6 were compared with those of the control mice (left). (B) Ten-weeks-old mice were ovariectomized, and starting 2 wk after the surgery, they were injected twice a day with PBS or M-CSF_RGD variants 4.22 or 5.6 for 3 d. Thereafter, serum CTX-I levels were determined by ELISA. Data are means ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001. Source data and its analysis can be found in S6 Data. CTX-I, carboxy-terminal telopeptide of type I collagen; ELISA, enzyme linked immunosorbent assay; M-CSF, macrophage colony-stimulating factor; OVX, ovariectomy-induced bone loss; PBS, phosphate-buffered saline; RGD, Arginine-Glycine-Aspartic acid; s.c., subcutaneously; WT, wild type.