Matrix Metalloproteinase-3 but Not Matrix Metalloproteinase-9, Implicated in the Manifestation of Chronic Periodontitis

Background: Periodontal disease is an inflammatory condition affecting the tooth's supporting tissues, resulting in gradual loss of periodontal ligament (PDL), alveolar bone, and gum resorption. Neutrophil and monocyte/macrophage, destructive proteases like matrix metalloproteinase (MMP)-3 and MMP-9 play pivotal roles in such lesions in periodontitis. Therefore, this study aims to compare the level of MMP-3 and MMP-9 gene expression in patients with or without periodontitis in an Iranian population.

Methods: This cross-sectional study was carried out on 22 chronic periodontitis patients and 17 healthy control subjects referred to the department of periodontology, Mashhad Dental School. In both groups, the gingival tissue was removed during surgery and transferred to the Molecular Biology Laboratory for MMP-3 and MMP-9 gene expression evaluation. The qRT-PCR, TaqMan method was used for gene expression assessments.

Results: The average age of periodontitis patients was 33± 5 years, and in controls, 34.7± 6 with no significant differences. The mean MMP-3 expression in periodontitis patients was 146.67±38.7, and in controls, 63.4±9.1. The difference was statistically significant (P=0.04). The mean expression of MMP-9 in periodontitis patients and controls were 103.8± 21.66 and 87.57± 16.05, respectively. Although the target gene expression in patients was higher, the difference was insignificant. Furthermore, there was not any significant correlation between age or gender with the expression of MMP3 or MMP9.

Conclusion: The study demonstrated that the MMP3 seems to have a destructive impact on the gingival tissue in chronic periodontitis, but not MMP9.