A genetic mouse model mimicking MET related human osteofibrous dysplasia is characterized by delays in fracture repair and defective osteogenesis

Osteofibrous dysplasia (OFD) is a rare, benign, fibro‐osseous lesion that occurs most commonly in the tibia of children. Tibial involvement leads to bowing and predisposes to the development of a fracture which exhibit significantly delayed healing processes, leading to prolonged morbidity. We previously identified gain‐of‐function mutations in the MET gene as a cause for OFD. In our present study, we test the hypothesis that gain‐of‐function MET mutations impair bone repair due to reduced osteoblast differentiation. A heterozygous Met exon 15 skipping (Met Δ15 ‐HET) mouse was created to imitate the human OFD mutation. The mutation results in aberrant and dysregulation of MET‐related signaling determined by RNA‐seq in the murine osteoblasts extracted from the wide‐type and genetic mice. Although no gross skeletal defects were identified in the mice, fracture repair was delayed in Met Δ15 ‐HET mice, with decreased bone formation observed 2‐week postfracture. Our data are consistent with a novel role for MET‐mediated signaling regulating osteogenesis.