Figure 1.
Disruption of circadian rhythm and BMAL1 expression in the skeletal system in senile osteoporosis
(A) PET scans of 2-month-old and 20-month-old C57BL/6J mice after 18F-NaF tail vein injection at the indicated times. ZT0 is defined as the time the light was turned on (8 a.m.). (B) PET analysis of maximum and mean SUV. (C and D) Western blot analysis of the levels of the core rhythm components BMAL1 and CLOCK in BM-MSCs from 2-month-old and 20-month-old mice, patients with traffic injuries and patients with senile osteoporosis. (E and F) HE staining (scale bar, 100 μm) of bone specimens from 2-month-old and 20-month-old mice, patients with traffic injuries and patients with senile osteoporosis. (G and H) Immunofluorescence staining (scale bar, 100 μm) showed Bmal1 and Clock expression in the Ocn+ osteoblast lineage in 2-month-old and 20-month-old mice (white arrows). (I-J) Immunofluorescence staining (scale bar, 100 μm) showed BMAL1 and CLOCK expression in the OCN+ osteoblast lineage in young patients and patients with senile osteoporosis (white arrows). All data are presented as mean ± SD; n = 3; ∗p < 0.05.