FIG. 6.

A SHIP1-deficient OC compartment does not lead to osteoporosis. (A) Monocytes were differentiated with RANKL and M-CSF and SHIP1 levels in OC from SHIP^flox/flox (+/+) and LysMCreSHIP^flox/flox (−/−) mice were assessed by western blot. Actin serves as a loading control and its relative quantification is indicated below. (B) Circulating monocyte in peripheral blood measured at 7, 25, and 40 weeks of age in male and female LysMCreSHIP^flox/flox (−/−) versus SHIP^flox/flox littermates (+/+). (C) Whole-body BMD by DEXA analysis, (D) Bv/Tv measurements and (E) in sagittal sections through the proximal metaphysis taken derived from microCT scans of 16-week-old male SHIP^flox/flox (+/+) and LysMCreSHIP^flox/flox (−/−) mice (these results are representative of four mice of each genotype). (F) Quantitative plots of colony forming unit-fibroblast (CFU-F) numbers (per 3×10⁶ cells) from 16-week-old male SHIP^flox/flox (+/+) (black bars) and LysMCreSHIP^flox/flox (−/−) (open bars), mice (n=5). (G) TRAP stained proximal tibia sections of SHIP^flox/flox (+/+) and LysMCreSHIP^flox/flox (−/−) (4× and 20× magnification). (H) TRAP staining of OCs prepared from BMM that were cultured with RANKL and M-CSF showed a ∼2.8-fold increase in OC numbers in 16 weeks LysMCreSHIP^flox/flox (−/−) versus SHIP^flox/flox littermates (+/+). Top panels are representative plates and the bottom panels are 10×-magnified images from these plates. (I) The corresponding bar graphs (SHIP^flox/flox (+/+) (black bars) and LysMCreSHIP^flox/flox (−/−) (open bars) to the right represent mean OC numbers as determined for cultures from four mice/genotype with BMM from each mouse analyzed in duplicate (±SEM, ***P≤0.0001, Student's unpaired, two-tailed t-test). Note: no significant differences were observed in BMD and Bv/Tv in female SHIP^flox/flox and LysMCreSHIP^flox/flox littermates. Color images available online at www.liebertpub.com/scd