Coordinate expression of BMP-2, BMP receptors and Noggin in normal mouse spine

The purpose of this study was to determine the localization of bone morphogenetic protein-2 (BMP-2), BMP receptors (BMPRs) and Noggin in mouse spinal tissues. The coordinate expression of these positive and negative regulators of BMP signaling may elucidate regulatory mechanisms for bone induction in the spine. Whole spines from 3-week-old mice were used and the spatial expression profiles of BMP-2, BMPR-1a, -1b, -2 and Noggin were examined using in situ hybridization. BMP-2, BMPR-1b and -2 were observed in bone marrow cells in the vertebrae, chondrocytes, hyaline cartilage cells and fibrous cells in the intervertebral discs and neurons of the spinal cord in the entire spine. BMPR-1a was also observed in these cells, but only in the cervical spine. Noggin was expressed in bone marrow cells in the vertebrae, chondrocytes and hyaline cartilage cells and fibrous cells in the intervertebral discs in the entire spine and in neurons in the spinal cord in the cervical and thoracic regions. Noggin was also expressed in the anterior longitudinal, posterior longitudinal and yellow ligaments in the cervical spine, and in the fibrous cells in the anterior longitudinal and yellow ligaments of the lumbar spine.