Id4, a New Candidate Gene for Senile Osteoporosis, Acts as a Molecular Switch Promoting Osteoblast Differentiation
Figure 8
4-week-old Id4−/− mice show increased adipocytes in bone marrow.
(A,B) Villanueva staining of epiphyseal tibia of Id4+/+ (A) and Id4−/− mice (B). (C,D) The BFR was measured in the tibial epiphysial regions in Id4+/+ (C) and Id4−/− mice (D) using a fluorescence microscopy following double-staining with tetracycline hydrochloride (blue arrowheads) and calcein (white arrowheads). Yellow arrowheads indicate adipocytes. The original magnifications and scale bars of the images are ×400 and 100 µm. (E) The total area occupied by adipocytes (Adi.V) in the epiphyseal tibia bone marrow. Id4+/+ (n = 6), Id4−/− (n = 6). (F) Pparγ2 mRNA expression is significantly elevated in bone marrow cells of Id4−/− compared to Id4+/+ mice. Relative expression levels of Pparγ2 mRNA were measured by qRT-PCR. Id4+/+ (n = 9), Id4−/− (n = 10). All data were subjected to Student's t-tests. Each error bar represents the mean ± SE. *p<0.05 versus control. (G) The role of Id4 in bone formation and bone marrow environment.