Expression and Regulation of a Disintegrin and Metalloproteinase-8 and -17 in Development of Rat Periradicular Lesion.

Abstract: Introduction: A disintegrin and metalloproteinases (ADAMs) are a family of transmembrane proteins that share a common domain structure. However, little is known about the possible involvement of ADAM-8 and ADAM-17 in the development of periradicular lesions. Here we demonstrated the expression of ADAM-8 and ADAM-17 in rat periradicular lesions. Methods: We induced experimentally periradicular lesions in rats. The animals were killed at 0, 2, 4, 6, and 8 weeks after pulp exposure. The left molars underwent immunofluorescence analysis for both ADAMs and for neutrophil elastase, and right molars were used for reverse transcription–polymerase chain reaction analysis of ADAM-8 and ADAM-17. The areas of these lesions were measured histometrically, and the numbers of all antigen-positive cells in the periapical portion were counted per unit area. Results: The area of the periradicular lesions gradually expanded from 0 to 4 weeks, showing a large increase from week 2 to week 4. Both ADAM-8–positive and ADAM-17–positive cells gradually increased in number from 0 to 4 weeks and then decreased from 4 to 8 weeks. There were more ADAM-17–expressing cells than ADAM-8–expressing ones at all experimental periods except at 4 weeks. The highest expression of ADAM-8 mRNA was observed at 4 weeks, and there were significant differences between 0 and 2 weeks and between 4 and 6 weeks. The expression of ADAM-17 mRNA increased from 0 to 4 weeks and subsequently decreased from 4 to 8 weeks, with a significant difference between 4 and 6 weeks. Conclusions: Our results suggest that ADAM-8 and ADAM-17 may be related to the development of rat periradicular lesions. [Copyright &y& Elsevier]

Copyright of Journal of Endodontics is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)