RGD-binding integrins participate in mechanotransduction in the mandibular condylar cartilage of rats submitted to functional orthopaedic treatment.

Author(s)

Mara Rubia Marques

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2007-06-01

Examining board members

Anselmo Sigari Moriscot; Jarbas Arruda Bauer; Cecilia Helena de Azevedo Gouveia Ferreira; Kleber Gomes Franchini; Gladys Cristina Dominguez Rodriguez

• Advisor: Marinilce Fagundes dos Santos

Abstract

The mandibular propulsor appliance is widely used in dentistry to modulate the growth of the condylar cartilage, through forces generated by postural changes in the orofacial musculature. The aim of this study was to evaluate the role of fibronectin (FN)-binding integrins in the transduction of mechanical forces generated by the appliance in rats. By immunohistochemistry and real time PCR it was observed that, in vivo, the appliance´s use modulated the expression of the integrin subunits <font face=\"symbol\">1, <font face=\"symbol>\"5, and <font face=\"symbol\">v, FN and PCNA, a cell proliferation marker. In vitro, the application of cyclic distension forces on condylar cartilage cells increased the expression of FN, IGF-I, IGF-II and PCNA mRNA. Addition of the peptide GRGDSP, which blocks the binding of some integrins to FN, inhibited all the effects except the increase in IGF-II mRNA. These results suggest that FN-binding integrins play an important role in mechanotransduction in this system, contributing to the understanding of the molecular basis involved in maxillary functional orthopedic therapy. (AU)