Wnt4 attenuates skeletal aging by inhibiting NF-κB. (a–c) µCT reconstruction (a), BMD and BV/TV (b), as well as H&E staining (c) of distal femoral metaphysis regions from 6-, 18- and 24-months-old WT and Wnt4 mice. Scale bars, 200 µm (a); 300 µm (c). (d) Morphometric analysis of osteoblast counts in distal femoral metaphysis from 3-, 18- and 24-months-old WT and Wnt4 mice. (e) ELISA of Ocn concentrations in serum from 3-, 18- and 24-months-old WT and Wnt4 mice. (f) Morphometric analysis of osteoclast counts in distal femoral metaphysis from 3-, 18- and 24-months-old WT and Wnt4 mice. (g,h) ELISA of Trap5b (g) and Il-6 (h) concentrations in serum from 3-, 18- and 24-months-old WT and Wnt4 mice. (i) Immunostaining with anti-active p65 and quantification of NF-κB activity surrounding the trabecular bones from 24-months-old WT and Wnt4 mice. Scale bars, 25 µm. For b, and d–i, n = 12 mice per group. *P < 0.05, ** P < 0.01, unpaired two-tailed t-test.