Gene and protein expression of brain-derived neurotrophic factor and TrkB in bone and cartilage

Gene and protein expressions of brain-derived neurotrophic factor (BDNF) an d TrkB, the high-affinity receptor of BDNF, were investigated in the femur and mandibular condyle of rats by in situ hybridization and immunohistochem istry. BDNF and TrkB mRNA showed overlapped expression in chondrocytes in p roliferating and mature zones of the epiphyseal growth plate cartilage and mandibular condylar cartilage, and in cuboidal-shaped active osteoblasts at the site of endochondral and intramembranous ossification and in trabecula r bone. Expression of BDNF protein also showed a similar localization. The present study suggests that BDNF may participate in regulating the developm ent and remodeling of bony tissue in the developing rat. (Bone 28:404-409; 2001) (C) 2001 by Elsevier Science Inc, All rights reserved.