Beta-catenin-dependent Wnt signaling in mandibular bone regeneration.
Osteoblasts are derived from two distinct embryonic lineages: cranial neural crest, and mesoderm. Both populations of cells are capable of forming bone and cartilage during fetal development and during adult bone repair, but whether they use equivalent molecular pathways to achieve osteoblast differentiation is unknown. We addressed this question in the context of cranial repair and focused on the role of Wnt signaling in mandibular skeletal healing. Transgenic Wnt reporter mice were used to pinpoint Wnt-responsive cells in the injury callus, and in situ hybridization was used to identify some of the Wnt ligands expressed by cells during the repair process. A gene transfer technique was employed to abrogate Wnt signaling during mandibular healing, and we found that reparative intramembranous ossification requires a functional Wnt pathway. Finally, we evaluated how constitutive activation of the Wnt pathway, caused by mutation of the LRP5 receptor, affected bone repair in the mandible. Taken together, these data underscore the functional requirement for Wnt signaling in cranial skeletal healing.
Leucht
Philipp
P
Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University Medical School, 257 Campus Drive, Stanford, CA 94305-5148, USA.
Kim
Jae-Beom
JB
Helms
Jill A
JA
D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D004195:Disease Models, Animal; D018014:Gene Transfer Techniques; D026502:LDL-Receptor Related Proteins / Q000235:genetics; D060492:Low Density Lipoprotein Receptor-Related Protein-5; D008297:Male; D008334:Mandible / Q000502:physiology*; D051379:Mice; D009154:Mutation; D015398:Signal Transduction; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism*
D026502:LDL-Receptor Related Proteins; D060492:Low Density Lipoprotein Receptor-Related Protein-5; C555483:Lrp5 protein, mouse; D051153:Wnt Proteins; D051176:beta Catenin