[Role of apoptosis and bcl-2 gene in the temporomandibular joint development].
OBJECTIVE
Apoptosis involving in embryogenesis and organ formation has been verified, but the possible roles of apoptosis and its related regulative genes have not been clarified. Temporomandibular joint dysfunction (TMD) has increased in incidence and occurred increasingly in young patients. Thus, research on the development and gene modulation is necessary.


METHODS
Tdt-mediated dUTP nick end labeling (TUNEL) and mRNA in situ hybridization were used in observation of apoptosis and bcl-2 gene expression in TMJ of SD rats during prenatal and postnatal developmental period.


RESULTS
Apoptosis involved in different development periods of condylar cartilage, and the cells of apoptosis mainly located in the proliferative zone and the area between the prehypertrophic zone and the late hypertrophic zone., bcl-2 was expressed in chondrocytes throughout condylar cartilage with high levels in proliferative and prehypertrophic chondrocytes and obvious low levels in the late hypertrophic chondrocytes. Very few matured chondrocytes expressed bcl-2.


CONCLUSIONS
Apoptosis regulated by bcl-2 plays an important role in prenatal and postnatal development of TMJ.
Li
S
S
Stomatological College, Fourth Military Medical University.
Jin
Y
Y
Wang
H
H
Li
Y
Y
D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D019254:Genes, bcl-2 / Q000235:genetics*; D017403:In Situ Hybridization; D008297:Male; D008335:Mandibular Condyle / Q000196:embryology* / Q000254:growth & development* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013704:Temporomandibular Joint / Q000196:embryology* / Q000254:growth & development* / Q000473:pathology