Osteoblast CFTR Inactivation Reduces Differentiation and Osteoprotegerin Expression in a Mouse Model of Cystic Fibrosis-Related Bone Disease
Figure 5
CFTR inactivation blocked Wnt3a and PTH-activated osteoblast canonical Wnt signaling.
(A) Calvarial osteoblasts harvested from Cftr+/+ and Cftr−/− mouse pups were cultured. Cyclic AMP accumulation, a marker of PTH receptor activation, was not significantly different between Cftr+/+ and Cftr−/− osteoblasts after 10 minutes of PTH (1–34) 10 nM treatment. (B) Activation of canonical Wnt signaling was assessed utilizing the TOP-Flash and FOP-Flash Wnt luciferase reporter vectors. Canonical Wnt activity increased after 48 hours of PTH (1–34) 10 nM and Wnt3a 10 ng/ml treatment in Cftr+/+ but not in Cftr−/− calvarial osteoblasts. (* = p<0.05; NS = not significant)