Demonstration of mitochondrial oestrogen receptor β and oestrogen-induced attenuation of cytochrome c oxidase subunit I expression in human periodontal ligament cells

Objective ontal ligament (PDL) cells express oestrogen receptor β (ERβ) protein, but cellular functions regulated by ERβ in these cells have not been identified. In this study we determine if ERβ is localised to mitochondria and if oestrogen regulates mitochondrial function in human PDL cells obtained from teeth extracted for orthodontic reasons. lular distribution of ERβ was determined by confocal microscopy of cells co-stained with ERβ antibody and the mitochondrion-selective probe MitoTracker and by immunogold electron microscopy. Expression of the mitochondrial enzyme cytochrome c oxidase subunit I, involved in oxidative phosphorylation, was determined by Western blotting in cells treated with or without physiological concentrations of the endogenous oestrogen 17β-oestradiol. s