Tissue differentiation and cytokine synthesis during strain-related bone formation in distraction osteogenesis.
To investigate the contributions of various cytokines that are involved in mechanically related bone formation, we applied defined uniaxial strains in a rabbit model of mandibular elongation and examined the regenerating bone during early stages of dist raction osteogenesis by histomorphometry. We also measured serum concentrations of various cytokines during the distraction. Cell proliferation and differentiation indices correlated significantly (P<0.001) with the extent of load application. Serum concentrations of insulin-like growth factor-1 (IGF-1) decreased after osteotomy whereas transforming growth factor beta1 (TGFbeta1) showed a postoperative increase. Prostaglandin E2 (PGE2) concentrations were constant throughout the experimental period. Collagen degradation decreased slightly postoperatively and increased in samples exposed to higher magnitudes of strain. Our data show that it is the magnitude of mechanical strain that decides tissue response by a characteristic cell proliferation and differentiation. The operative trauma leads to inverse changes in serum concentrations of TGFbeta1 and IGF-1, thereby promoting the recruitment of osteoblastic precursor cells as well as collagen matrix synthesis.
Meyer
U
U
Clinic of Maxillofacial Surgery, University of Münster, Germany.
Meyer
T
T
Schlegel
W
W
Scholz
H
H
Joos
U
U
D000818:Animals; D002146:Bony Callus / Q000033:anatomy & histology; D002454:Cell Differentiation; D003094:Collagen / Q000097:blood; D024042:Collagen Type I; D003799:Dental Stress Analysis; D015232:Dinoprostone / Q000097:blood; D005260:Female; D006651:Histocytochemistry; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D008334:Mandible / Q000378:metabolism / Q000601:surgery*; D023421:Models, Animal; D010006:Osteoblasts / Q000378:metabolism; D015675:Osteocalcin / Q000096:biosynthesis / Q000097:blood; D010012:Osteogenesis / Q000502:physiology*; D019857:Osteogenesis, Distraction; D010455:Peptides / Q000097:blood; D011817:Rabbits; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000097:blood
D024042:Collagen Type I; D010455:Peptides; D016212:Transforming Growth Factor beta; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I; D003094:Collagen; D015232:Dinoprostone