Steroid 5alpha-reductase activity of Treponema denticola

Porphyromonas gingivalis enhances the senescence-induced increase of 5-alpha reductase in gingival fibroblasts

OBJECTIVES

Aging is characterized by chronic inflammatory activity. Senescent cells increase with chronic inflammation and age-related pathologies, including periodontal disease. As a critical regulator of tissue inflammaging, we hypothesized that 5α reductase (5αR) is associated with periodontal disease and bacteria-induced senescence in gingival fibroblasts.

MATERIALS AND METHODS

We recruited 36 patients with periodontitis, measured 5αR immunohistochemically before and after periodontal treatment, and compared the expression of 5αR in gingival biopsies from 12 healthy individuals. We then tested the impact of Porphyromonas gingivalis on gingival fibroblasts treated with or without D-galactose-induced cell senescence. We treated primary gingival fibroblasts with D-galactose-supplemented media (0 µM, 50 µM, 100 µM, 1 mM, 10 mM, 50 mM) to induce senescence. The expression of type 1 and type 2 5αR was analyzed with real-time PCR and immunocytochemistry. The levels of IL-6, IL-8, TNF-α, and MCP-1 in fibroblast cultures were evaluated by multiplex immunoassay.

RESULTS

In gingival biopsies from patients with periodontal disease, the expression of 5αR was significantly higher than in samples from individuals without periodontal disease (p < 0.001). Periodontal treatment significantly reduced the expression of 5αR in gingival tissues (p < 0.001) to levels comparable in healthy individuals. Gingival fibroblasts exposed to D-galactose-supplemented media had a dose-dependent and significant increase in 5αR expression (p < 0.001). P. gingivalis caused statistically higher type 1 and type 2 5αR expression in gingival fibroblast cells. This effect was exacerbated by the lower doses of D-galactose (p = 0.037). Cells infected with P. gingivalis produced significantly higher levels of IL-6, IL-8, TNF-α, and MCP-1 (p < 0.05) regardless of the D-galactose exposure.

CONCLUSION

The results suggested that 5αR plays a role in periodontal disease and mediates the senescence-induced response to P. gingivalis in gingival fibroblasts.

CLINICAL RELEVANCE

Periodontal diseases and aging can increase the production of 5-alpha reductase in the gingival tissue.

Sex Steroid Hormones as a Balancing Factor in Oral Host Microbiome Interactions

Sex steroid hormones (SSH) are cholesterol-derived molecules. They are secreted into saliva and enter the oral cavity, triggering physiological responses from oral tissues, with possible clinical implications, such as gingival inflammation and bleeding. SSH and hormonal changes affect not only oral host cells but also oral microorganisms.

Historically, most research has focused on the effect of hormonal changes on specific bacteria and yeasts. Recently a broader effect of SSH on oral microorganisms was suggested. In order to assess the role of SSH in host-microbe interactions in the oral cavity, this review focuses on how and up to what extent SSH can influence the composition and behavior of the oral microbiome. The available literature was reviewed and a comprehensive hypothesis about the role of SSH in host-microbiome interactions is presented. The limited research available indicates that SSH may influence the balance between the host and its microbes in the oral cavity.