Functional effects of estrogen in the periodontium

• Objectives: Several studies have addressed the association between changes in the female sex hormones estrogen and progesterone levels and changes in parameters of periodontitis. We have previously shown that periodontal ligament cells (PDL cells) express estrogen receptor β (ERβ) but not ERα immunoreactivity. The PDL cells express no immunoreactivity for progesterone receptors, suggesting that this cell-type is not affected by progesterone. Treatment with a physiological concentration of estrogen increases DNA synthesis in human breast cancer cells but has no effect on PDL cell DNA and collagen synthesis. The purpose of this project is to investigate the mechanisms by which estrogen influences structure and function of the periodontal ligament by affecting PDL cell functional properties. Methods: Human PDL cells were obtained from teeth extracted for orthodontic reasons. The cells were cultured from periodontal tissue explants and used in passages 3-5. Subcellular distribution of ERβ was determined by immunogold electron microscopy and confocal imagining using the mitochondrial selective probe MitoTracker and ERβ immunostaining. Expression of mitochondrial protein cytochrome c oxidase subunit I was investigated using Western blotting. The amount of IL-6 was determined by ELISA. Results: Confocal imaging revealed that ERβ immunoreactivity was distributed not only in the nucleus but also in the mitochondria. These results were confirmed using immunogold electron microscopy. Incubation with estrogen down-regulated the mitochondrial enzyme cytochrome c oxidase subunit I expression by about 30%, showing functional significance of mitochondrial ER. Preliminary data show that estrogen attenuates LPS induced IL-6 production in the PDL cells. Conclusion: Our data show that estrogen, preferably via ERβ, affects PDL cell functional properties, suggesting that estrogen and other ER specific ligands may modulate the periodontal tissue structure and function in health and disease.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Odontologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Dentistry (hsv//eng)

Nyckelord

Periodontal ligament cells

estrogen receptor

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