Objective. To investigate the function of bone morphogenic protein-2 (BMP-2
) in the ossification of the spinal ligament (OSL).
Methods. Total RNA was prepared from the cultured spinal ligament cells fro
m patients with OSL and analysed by reverse transcription-polymerase chain
reaction using specific primers for BMP-2. BMP-2 mRNA expression in ligamen
t tissues was examined by in situ hybridization. Spinal ligament cells from
patients without OSL were treated with BMP-2 and examined for alkaline pho
Results. Expression of the BMP-2 gene was detected in cultured spinal ligam
ent cells. In ligament tissues, BMP-2 mRNA was present in the chondrocyte-l
ike cells in the fibrocartilage zone. Exogenous BMP-2 increased alkaline ph
osphatase activity in spinal ligament cells from patients without OSL.
Conclusion. The BMP-2 gene is expressed in the spinal ligaments of OSL pati
ents, and exogenous BMP-2 stimulates osteogenic differentiation of spinal l
igament cells. The expression of BMP-2 in the spinal ligaments could be a c
lue in elucidating how heterotrophic osteogenesis develops in ligament tiss