Role of nuclear receptors for oxysterols LXR alpha and beta in female reproductive physiology in mice
Cholesterol is an essential nutrient although toxic in excess, naturally converted into oxysterols. LXRs (Liver X Receptor) α and β are nuclear receptors for oxysterols which have a hypocholesterolemiant role and control many physiologic functions. Our aim was to study their role in female reproductive physiology. In the ovary, ovulation induction in lxrα;β-/- mice caused an ovarian hyperstimulation (OHSS), characterized by ovarian enlargement, vascular troubles and increased hormonal sensitivity. Besides, LXRs control estradiol production. In the uterus, we pointed the existence of a specific function for LXRβ. Lxrβ-/- mice present an abnormal sequestration of cholesteryl esters in myocytes associated with an uterine contractility defect. These data point for the first time the importance of the LXRs in female reproductive function and will help in the future to understand mechanisms involved in fertility defects due to alimentary disequilibrium.