The BMP signaling and its Smads in mandibular distraction osteogenesis.
OBJECTIVE
The aim of the present study was to clarify the mechanism of signal transduction of bone morphogenetic proteins (BMPs) through their specific down signaling molecules Smads inducing bone formation in response to mechanical stimulus during distraction osteogenesis (DO) in the rat mandible.


METHODS
Osteotomy of the left mandible was performed in 45 rats. Thirty rats underwent mandibular distraction (protocol; 5 days latency, 8 days distraction, and 2 weeks consolidation) while 15 rats served as non-distracted (fracture healing) group. The expression of BMPs-2,-4 and Smads 1, 5, and 8 were evaluated in the new regenerate area using immunohistochemistry.


RESULTS
Expressions of BMPs-2,-4 and Smads 1, 5, and 8 were moderate during latency, significantly increased during distraction and decreased towards consolidation period.


CONCLUSIONS
The enhanced expression of BMPs and its Smads during distraction compared to the non-distracted group suggests the possible role of BMP signaling pathway in translation of mechanical forces into biological results during DO.
Khanal
A
A
Division of Maxillofacial Diagnostic and Surgical Science, Department of Oral and Maxillofacial Surgery, Kyushu Dental College,Kitakyushu, Japan.
Yoshioka
I
I
Tominaga
K
K
Furuta
N
N
Habu
M
M
Fukuda
J
J
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis / Q000502:physiology*; D001861:Bone Regeneration / Q000502:physiology*; D003799:Dental Stress Analysis; D017102:Fracture Healing / Q000502:physiology; D015870:Gene Expression; D007150:Immunohistochemistry; D008297:Male; D008334:Mandible / Q000601:surgery*; D023421:Models, Animal; D019647:Oral Surgical Procedures; D019857:Osteogenesis, Distraction; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D051785:Smad Proteins / Q000096:biosynthesis* / Q000502:physiology; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000502:physiology; D015854:Up-Regulation
C525720:Bmp2 protein, rat; C525811:Bmp4 protein, rat; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D051785:Smad Proteins; D016212:Transforming Growth Factor beta