Involvement of bone morphogenic protein-2 (BMP-2) in the pathological ossification process of the spinal ligament.
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 from patients with OSL and analysed by reverse transcription-polymerase chain reaction using specific primers for BMP-2. BMP-2 mRNA expression in ligament tissues was examined by in situ hybridization. Spinal ligament cells from patients without OSL were treated with BMP-2 and examined for alkaline phosphatase activity.


RESULTS
Expression of the BMP-2 gene was detected in cultured spinal ligament cells. In ligament tissues, BMP-2 mRNA was present in the chondrocyte-like cells in the fibrocartilage zone. Exogenous BMP-2 increased alkaline phosphatase activity in spinal ligament cells from patients without OSL.


CONCLUSIONS
The BMP-2 gene is expressed in the spinal ligaments of OSL patients, and exogenous BMP-2 stimulates osteogenic differentiation of spinal ligament cells. The expression of BMP-2 in the spinal ligaments could be a clue in elucidating how heterotrophic osteogenesis develops in ligament tissue.
Tanaka
H
H
Department of Orthopedic Surgery, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
Nagai
E
E
Murata
H
H
Tsubone
T
T
Shirakura
Y
Y
Sugiyama
T
T
Taguchi
T
T
Kawai
S
S
D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D015870:Gene Expression; D006801:Humans; D017403:In Situ Hybridization; D017846:Longitudinal Ligaments / Q000201:enzymology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000378:metabolism* / Q000473:pathology*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013130:Spinal Stenosis / Q000378:metabolism / Q000473:pathology; D013131:Spine / Q000473:pathology*; D016212:Transforming Growth Factor beta
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D000469:Alkaline Phosphatase