Análisis inmunohistoquímico de MMP-1, MMP-2 y MMP-9 en ameloblastoma convencional / Immunohistochemical analysis of MMP-1, MMP-2, MMP-9 in conventional ameloblastoma

Introducción: las metaloproteinasas son enzimas que participan en la remodelación tisular y su función se relaciona con procesos fisiológicos y patológicos, como la invasión y la metástasis. El ameloblastoma convencional (AMC) es una neoplasia epitelial benigna odontogénica intraósea caracterizada por una progresión lenta y localmente invasiva, cuyo crecimiento se ha vinculado con el recambio ósea y la remodelación de la matriz extracelular. El objetivo del presente trabajo fue determinar la presencia inmunohistoquímica de MMP-1, MMP-2 y MMP-9 en el AMC. Material y métodos: se realizó un estudio piloto observacional analítico utilizando cinco muestras de AMC. Los especímenes fueron recolectados aleatoriamente del archivo del Departamento de Patología Oral y Maxilofacial, de la Escuela Nacional de Estudios Superiores (ENES) Unidad León, UNAM. Como grupo control se emplearon dos especímenes de folículo dental, obtenido de pacientes con indicación de su extracción por motivos ortodóncicos. Se realizó la técnica de inmunohistoquímica por peroxidasa, recolectando el nivel y proporción de inmunoexpresión de manera semicuantitativa. Resultados: cuatro pacientes fueron de género masculino y uno femenino, la edad promedio fue de 40.6 ± 14.9 años. Todas las muestras fueron obtenidas de la región mandibular posterior. Se observaron dos especímenes con patrón folicular y tres con plexiforme. Las MMP-2 y MMP-9 se detectaron sólo en uno de los cinco especímenes y únicamente en el parénquima de la lesión, con una proporción de 100%. Conclusión: según nuestro análisis inmunohistoquímico, las MMP-2 y MMP-9 son las metaloproteinasas que presentaron expresión positiva dentro de la patogénesis del AMC comparado a la MMP-1; no obstante, es necesario realizar este tipo de estudios en una población mayor (AU)

Introduction: metalloproteinases are enzymes involved in tissue remodeling and their function is related to physiological and pathological processes, such as invasion and metastasis. These enzymes are capable of degrading components of the extracellular matrix, which may promote tumor progression. Conventional ameloblastoma (CA) is described as a benign intraosseous epithelial odontogenic neoplasm characterized by a slow and locally invasive progression, whose growth has been linked to bone turnover and extracellular matrix remodeling. The aim of the present work was to determine the immunohistochemical presence of MMP-1, MMP-2 and MMP-9 in CA. Material and methods: an analytical observational pilot study was performed using 5 CA, randomly collected from the archive of the Department of Oral and Maxillofacial Pathology, Escuela Nacional de Estudios Superiores (ENES) Unidad León, UNAM. The control group used were two dental follicle samples, obtained from patients with extraction indication for orthodontic treatment. The peroxidase immunohistochemistry assay was performed, collecting semiquantitatively level and proportion of immunoexpression. Results: four patients were male and one female, the average age was 40.6 ± 14.9 years. All specimens were obtained from the posterior mandibular region. Two specimens were observed with follicular pattern and three with plexiform pattern. MMP-2 and MMP-9 were detected only in one of the five specimens, with presence in the parenchyma of the lesion, with a proportion of 100% of the cell analyzed. Conclusion: according to our immunohistochemical analysis, MMP-2 and MMP-9 are the metalloproteinases that presented positive expression within the pathogenesis of CA compared to MMP-1; however, it is necessary to perform this type of studies in a larger population (AU)

Porphyromonas gingivalis decreases osteoblast proliferation through IL-6-RANKL/OPG and MMP-9/TIMPs pathways.

Background: Porphyromonas gingivalis, an important periodontal pathogen, is closely associated with inflammatory alveolar bone resorption. This bacterium exerts its pathogenic effect indirectly through multiple virulence factors, such as lipopolysaccharides, fimbriae, and proteases. Another possible pathogenic path may be through a direct interaction with the host's soft and hard tissues (e.g., alveolar bone), which could lead to periodontitis. Aims and Objectives: The aim of the present study was to investigate the direct effect of live and heat-inactivated P gingivalis on bone resorption, using an in vitro osteoblast culture model. Results: Optical microscopy and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide MTT assay revealed that live P gingivalis induced osteoblast detachment and reduced their proliferation. This effect was specific to live bacteria and was dependent on their concentration. Live P gingivalis increased IL-6 mRNA expression and protein production and downregulated RANKL and OPG mRNA expression. The effect of live P gingivalis on bone resorption was strengthened by an increase in MMP-9 expression and its activity. This increase was accompanied by an increase in TIMP-1 and TIMP-2 mRNA expression and protein production by osteoblasts infected with live P gingivalis. Conclusion: Overall, the results suggest that direct contact of P gingivalis with osteoblasts induces bone resorption through an inflammatory pathway that involves IL-6, RANKL/OPG, and MMP-9/TIMPs.