Changes of caspase-1 after the application of orthodontic forces in the periodontal tissues of rats.
OBJECTIVE
To investigate the changes of caspase-1 in orthodontic tooth movement and to determine whether the changes are phase-specific.


METHODS
Eighty Wistar rats were included in this study. Sentalloy closed-coil springs were placed to induce a mesial traction force on the lower right first molar. The animals were killed after 1, 3, 7, and 14 days (n = 20 at each time point). The mandibles of 10 rats were sampled for histomorphometric analysis and immunohistochemical assay, and the periodontal tissues of 10 other rats were sampled for detecting caspase-1 mRNA and protein by real-time RT-PCR and by Western blotting, respectively.


RESULTS
The inflammatory reaction was evident in paraffin sections with hematoxylin-eosin staining. The immunohistochemical assay showed that orthodontic forces significantly increased the number of caspase-1-positive cells in the periodontal ligament (PDL). Mechanical force triggered an increase of caspase-1 mRNA in periodontal tissues. The expression of caspase-1 mRNA increased from day 1, reached the peak on day 3, and then decreased. The results of Western blotting indicated that the levels of both procaspase-1 and P20 subunit significantly increased after the application of orthodontic forces, compared with those in controls (P < .05).


CONCLUSIONS
Caspase-1 level increases during orthodontic tooth movement and changes with different phases, which might play a significant role in orthodontic tooth movement.
Department of Orthodontics, School of Stomatology, China Medical University, Liaoning, China. chbyxl@163.com
Xiulin
X
Yan
Jiang
J
Chen
Yuquan
Y
Hao
Yan
Y
Wang
Li
L
Zhu
D000818:Animals; D001696:Biomechanical Phenomena; D015153:Blotting, Western; D020170:Caspase 1 / Q000032:analysis*; D008297:Male; D008963:Molar / Q000473:pathology; D009969:Orthodontic Wires; D010513:Periodontal Ligament / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical; D013997:Time Factors; D014087:Tooth Movement Techniques
D012333:RNA, Messenger; D020170:Caspase 1