Evaluation of MMP-1 and VEGF expression in the lamina propria of the eruptive pathway of rat molars

• Grant number: 11/23064-9
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2012
• Effective date (End): December 31, 2012
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Paulo Sergio Cerri
• Grantee: José Paulo de Pizzol Júnior
• Home Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Tooth eruption is a complex process responsible for movement of teeth germ from bony crypt to the occlusal plane. During this process, structural changes, such as degradation and remodelling of the extracellular matrix of lamina propria, are necessary for establishment of the eruptive pathway. Collagen, the main component of the extracellular matrix, must be degraded during the eruptive process. When the extracellular matrix is remodelled, the microvasculature may be reorganized in the lamina propria, avoiding exposition of the connective tissue and the vasculature to the oral environment. The aim of this study is to investigate possible changes in the arrangement and amount of collagen fibers; moreover, quantitative alterations in the blood vessels will also be evaluated in the lamina propria during tooth eruption. Fragments of maxilla containing the first molars, obtained from 9-, 11-, 13- and 16-day-old rats, will be removed and immediately fixed in formaldehyde. After decalcification, the fragments will be processed and embedded in paraffin. Sagittal sections stained by H/E will be used for selection of interest area. Sections will also be submitted to picrosirius method with the aim to amplify the birefringence of collagen fibers and perform the morphological analysis in the polarized light microscope. The expression of matrix metalloproteinase-1 (MMP-1) and VEGF (endothelial cell marker) in the lamina propria will be evaluated by immunohistochemistry. The numerical density of blood vessels in the lamina propria of the eruptive pathway will be obtained using an image analysis system (Image-Pro Express, Olympus). The differences among groups will be statistically analyzed by the Sigma Stat 2.0 program (Jandel Scientific, Sausalito, CA).

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE PIZZOL JUNIOR, JOSE PAULO; SASSO-CERRI, ESTELA; CERRI, PAULO SERGIO. Matrix Metalloproteinase-1 and Acid Phosphatase in the Degradation of the Lamina Propria of Eruptive Pathway of Rat Molars. CELLS, v. 7, n. 11 NOV 2018. Web of Science Citations: 1.

DE PIZZOL JUNIOR, JOSE PAULO; SASSO-CERRI, ESTELA; CERRI, PAULO SERGIO. Apoptosis and reduced microvascular density of the lamina propria during tooth eruption in rats. Journal of Anatomy, v. 227, n. 4, p. 487-496, OCT 2015. Web of Science Citations: 3.