Periostin Is Essential for the Integrity and Function of the Periodontal Ligament During Occlusal Loading in Mice

• Autores: Héctor F. Ríos, D. Ma, Y. Xie, William V. Giannobile, L.F. Bonewald, S.P. Conway, J.Q. Feng
• Localización: Journal of periodontology, ISSN 0022-3492, Vol. 79, Nº. 8, 2008, págs. 1480-1490
• Idioma: inglés
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• Resumen

  • Background: The ability of the periodontal ligament (PDL) to absorb and distribute forces is necessary for periodontal homeostasis. This adaptive response may be determined, in part, by a key molecule, periostin, which maintains the integrity of the PDL during occlusal function and inflammation. Periostin is primarily expressed in the PDL and is highly homologous to βig-H3 (transforming growth factor-beta [TGF-β] inducible gene). Cementum, alveolar bone, and the PDL of periostin-null mice dramatically deteriorate following tooth eruption. The purpose of this study was to determine the role of periostin in maintaining the functional integrity of the periodontium.

    Methods: The periodontia from periostin-null mice were characterized followed by unloading the incisors. The effect of substrate stretching on periostin expression was evaluated using a murine PDL cell line. Real-time reverse transcription-polymerase chain reaction was used to quantify mRNA levels of periostin and TGF-β. TGF-β1 neutralizing antibodies were used to determine whether the effects of substrate stretching on periostin expression are mediated through TGF-β.

    Results: Severe periodontal defects were observed in the periostin-null mice after tooth eruption. The removal of masticatory forces in periostin-null mice rescue the periodontal defects. Periostin expression was increased in strained PDL cells by 9.2-fold at 48 hours and was preceded by a transient increase in TGF-β mRNA in vitro. Elevation of periostin in response to mechanical stress was blocked by the addition of 2.5 ng/ml neutralizing antibody to TGF-β1, suggesting that mechanical strain activates TGF-β to have potential autocrine effects and to increase periostin expression.

    Conclusion: Mechanical loading maintains sufficient periostin expression to ensure the integrity of the periodontium in response to occlusal load.