Immunolocalization of bone morphogenetic protein and its receptors in degeneration of intervertebral disc.
METHODS
Immunohistochemical study of expression and localization of bone morphogenetic protein (BMP)-2/4 and type I and II receptors on intervertebral disc.


OBJECTIVE
To determine the biologic functions of BMPs and their receptors in the process of degeneration of the intervertebral disc.


BACKGROUND
Biologic and pathologic processes in the cell during the degeneration of the intervertebral disc are as yet poorly understood.


METHODS
The cervical spines of 15 male senescence-accelerated mice aged 8, 24, or 50 weeks were used for histologic and immunohistochemical examination of BMP-2/4 and BMP receptors IA, IB, and II. Immunostaining was performed with the avidin-biotin-peroxidase complex method.


RESULTS
Degenerative change was recognized within intervertebral discs of senescence-accelerated mice aged 50 weeks. BMP-2/4 and its receptors were abundant in hyaline cartilaginous cells within the endplate of the vertebrae at 8 and 24 weeks of age. However, the expression of BMP-2/4 and its receptors moved from the hyaline cartilage of the endplate of the vertebrae to fibrous cells within the anulus and to the calcified cartilage at the site of enthesis of mice aged 50 weeks.


CONCLUSIONS
BMP-2/4 and its receptors may play roles in degenerative change of intervertebral disc.
Takae
R
R
Department of Physical Therapy, School of Allied Medical Sciences.
Matsunaga
S
S
Origuchi
N
N
Yamamoto
T
T
Morimoto
N
N
Suzuki
S
S
Sakou
T
T
D000375:Aging; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D052005:Bone Morphogenetic Protein Receptors, Type I; D052006:Bone Morphogenetic Protein Receptors, Type II; D019485:Bone Morphogenetic Proteins / Q000378:metabolism / Q000502:physiology*; D002574:Cervical Vertebrae / Q000737:chemistry; D007124:Immunoenzyme Techniques; D007403:Intervertebral Disc / Q000737:chemistry; D007405:Intervertebral Disc Displacement / Q000209:etiology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D017346:Protein Serine-Threonine Kinases / Q000032:analysis; D011956:Receptors, Cell Surface / Q000032:analysis; D017978:Receptors, Growth Factor / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000502:physiology
C525719:Bmp2 protein, mouse; C525810:Bmp4 protein, mouse; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D011956:Receptors, Cell Surface; D017978:Receptors, Growth Factor; D016212:Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; C498219:Bmpr2 protein, mouse; D052005:Bone Morphogenetic Protein Receptors, Type I; D052006:Bone Morphogenetic Protein Receptors, Type II