IADR Abstract Archives

Appearance of DCC/Netrin in tooth germ during mouse molar odontogenesis

Objectives: During tooth eruption apoptosis is observed in the dental lamina, enamel knot and periodontal tissue. Therefore, apoptosis has been suggested to play important roles in normal tooth formation and eruption. However, the factors which induce apoptosis in these cells remain to be elucidated. In this study, we focused on DCC, which is known to induce apoptosis, and its ligand Netrin-1.When Netrin-1 is absent, DCC induces apoptosis. To investigate the participation of DCC to apoptosis in dental lamina and periodontal tissue during mouse molar tooth eruption, we performed immunohistochemistry and TUNEL staining.

Methods: Postnatal day 1-10(1, 3, 5, 7, 9, and 10) mice were used. Under deep anesthesia, the animals were perfused, and the upper second molar(M2) was removed. Cryosections were immunostained using antibodies against DCC and Netrin-1. And TUNEL staining was performed on the same section using In Situ Cell Death Detection Kit. The immunostaining and TUNEL staining of M2 were observed using fluorescence microscopy.

Results: Dental lamina: postnatal day 1(P1); DCC(+), Netrin-1(+) and TUNEL(-). P9; DCC(+), Netrin-1(-) and TUNEL(+). While, under the resorbing bone around M2 at P10(just before tooth eruption): DCC(+), Netrin-1(+) and TUNEL(+).

Conclusion: These results in dental lamina suggested that apoptosis, which induced by DCC, involved in reduction of dental lamina, and that apoptosis was inhibited when DCC was occupied by Netrin-1. While the results in under the resorbing bone around M2 suggested that apoptosis, which regulated by DCC/Netrin-1 interaction was not involved in the mechanism of bone resorption.


Japanese Division Meeting
2011 Japanese Division Meeting (Hiroshima, Japan)
Hiroshima, Japan
2011

Scientific Groups
  • Nakagawa, Ayako  ( Kyushu Dental College, Kitakyusyu, N/A, Japan )
  • Goto, Tetsuya  ( Kyushu Dental College, Kitakyushu, N/A, Japan )
  • Kataoka, Shinji  ( Kyushu Dental College, Kitakyushu, N/A, Japan )
  • Kobayashi, Shigeru  ( Kyushu Dental College, Kitakyushu, N/A, Japan )
  • Maki, Kenshi  ( Kyushu Dental College, Kitakyusyu, N/A, Japan )
  • Craniofacial Biology