Sirt3 Rescues Porphyromonas gingivalis-Impaired Cementogenesis via SOD2 Deacetylation

Area of Science:

• Biochemistry
• Cell Biology
• Periodontology

Background:

• Porphyromonas gingivalis (P.g.) is a key pathogen in periodontitis, causing cementum resorption through unclear mechanisms.
• Sirtuin 3 (Sirt3), a mitochondrial deacetylase, plays a role in cellular functions and homeostasis.

Purpose of the Study:

• To elucidate the mechanism by which P.g. affects cementogenesis.
• To investigate the role of Sirt3 in cementoblast function and its regulation by P.g.
• To evaluate honokiol (HKL) as a potential therapeutic agent targeting Sirt3.

Main Methods:

• Comparative analysis of Sirt3 expression in cementoblasts under P.g. infection and in Sirt3 knockout mice.
• In vitro studies using Sirt3 inhibition (3-TYP, shRNA) and activation (HKL).
• Assessment of cementoblast mineralization, expression of key genes (Runx2, OCN), and downstream molecule SOD2 activity and acetylation.

Main Results:

• Sirt3 expression decreased under P.g. infection, impairing cementogenesis and reducing Runx2/OCN levels.
• Sirt3 deficiency in mice led to reduced cementum and mineralization capacity.
• HKL activated Sirt3, promoting cementoblast mineralization and counteracting P.g.-induced suppression.
• Sirt3 deacetylated SOD2 at K68, a process disrupted by P.g. infection but restored by HKL.

Conclusions:

• Sirt3 deacetylates SOD2 at K68, playing a crucial role in regulating P.g.-affected cementogenesis.
• HKL shows potential as a therapeutic agent by activating Sirt3 and restoring cementum formation.