IL-23 plays a critical role in aging-mediated bone loss. (A) Micro-CT images of the trabecular bone in the distal femoral metaphysis of 12-month-old male WT mice and age-sex matched IL-12p35-/- and IL-12p40-/- mice. n = 4 per group. Scale bar, 1mm (upper and middle panel), 100 µm (lower panel). (B) Micro-CT measurements for the indicated parameters in distal femurs. Bone mineral density (BMD), bone volume/tissue volume (BV/TV), trabecular numbers (Tb.N), and trabecular thickness (Tb.Th) were determined by micro-CT analysis. n = 4 per group. (C) The H&E staining of femur sections from 12-month-old WT, IL-12p35-/-, and IL-12p40-/- mice were shown. n = 4 per group. Scale bar, 50 µm. (D) Trabecular percentage (%) was quantified via H&E images from the groups described in C. n = 4 per group. (E, F) The immunohistochemical analysis (E) and quantification (F) of ALP expression in the distal femoral metaphysis. n = 4 per group. Scale bar, 50 µm. (G, H) The immunohistochemical analysis (G) and quantification (H) of TRAP expression in the distal femoral metaphysis. n = 4 per group. Scale bar, 50 µm. ALP, alkaline phosphatase; TRAP, tartrate-resistant acid phosphatase; WT, wild-type. Results are shown as mean ± S.D. *p<0.05, **p<0.01.