Relation among MMPs, TIMPs and collagen organization with periodontal ligament resistence force to eruption moviment in incisor rats

• Grant number: 08/09141-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2009
• End date: September 30, 2011
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Pedro Duarte Novaes
• Grantee: Nádia Fayez Omar
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Periodontal ligament is a fiber connective tissue which occupies the space between the tooth and its alveolus, connecting cementum to alveolar bone by means of collagen fibers, its main function is teeth support. Studies showed that protein metabolism is higher and collagen fibers turnover is very fast. Due to a probable role of periodontal ligament in tooth functional movements, the remodelation mechanism of collagen has been much investigated.In continuous eruption and growth teeth, as rodent incisors, periodontal ligament occupies lingual, medial and a piece of distal face of the tooth. The constant eruption movement that occurs in incisors as the erosion of tooth is accompanied by intense remodelation activity of periodontal ligament.The extracellular matrix remodelation of periodontal ligament occurs by direct action of enzymes called metalloproteinases (MMPs) and their endogenous inhibitors, called TIMPs. In spite of studies showed the role of MMPs in periodontal ligament, the MMPs and TIMPs activity and relation with resistance of periodontal ligament as well as with collagen organization in this tissue is unclear yet. In the same way, it is insufficient knowledge about these relations in different dental eruption conditions and function. Rat incisor has been used as study model of alterations of dental eruption and periodontal ligament metabolism, because in these teeth the function conditions can be easily altered, permitting to investigate biochemical, structural and metabolic changes of their tissues.Therefore, the relation among periodontal ligament resistance to eruption movement, the extracellular matrix remodelation quick and MMPs and TIMPs activity, they are parameters that may contribute to understand better the eruption process and biology.In this way, the present study proposes verify the relation among: 1) eruption rate of lower incisor rat; 2) periodontal ligament resistance force; 3) MMP-2, -9, MT1-MMP and TIMPs expression on periodontal ligament, and 4) periodontal ligament collagen organization; using techniques as zymography, reverse zymography and western blotting, over polarization microscopy.The 1 and 2 objectives were already carry out and showed that eruption rate was greater in hypofunctional group than other groups, and less in restrain group than others. Periodontal ligament resistance force in hypofunctional teeth was less than normalfunctional group, indicating possible alterations in molecules that are involved in extracellular remodelation process on periodontal ligament.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

OMAR, Nádia Fayez. MMPs, TIMP-2 and collagen organization relation with the strength of resistance that the PL offers to the eruptive in rat incisors. 2011. Doctoral Thesis - Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba Piracicaba, SP.