Effect of Vitamin D(3) on Chemerin and Adiponectin Levels in Uterus of Polycystic Ovary Syndrome Rats

Background: Polycystic ovary syndrome (PCOS) is an endocrine disorder with disrupted uterus structure and function. A positive effect of vitamin D(3) (VD(3)) in female reproduction was observed. Chemerin (RARRES2) and adiponectin (ADIPOQ) are the main adipokines whose levels are altered in PCOS patients. Therefore, the aim of this study was to investigate the impact of VD(3) supplementation on RARRES2 and ADIPOQ levels in the uterus of PCOS rats. Methods: We analyzed the plasma levels and uterine transcript and protein expression of RARRES2 and ADIPOQ and their receptors (CCRL2, CMKLR1, GPR1, and ADIPOR1 and ADIPOR2, respectively) in rats with letrozole-induced PCOS. Results: In control animals, VD(3) did not change plasma levels of both adipokines, while in PCOS rats supplemented with VD(3), they returned to control levels. The expression of RARRES2 and all investigated receptors increased in the uterus of VD(3)-treated rats; however, the levels of Rarres2 and Gpr1 genes remained unchanged. VD(3) supplementation decreased RARRES2, CMKLR1, and GPR1 but increased CCRL2 level to the control value. In the uterus of VD(3)-treated rats, the transcript and protein levels of ADIPOQ and both receptors ADIPOR1 increased. At the same time, VD(3) supplementation induced an increase in Adipoq, Adipor1, and Adipor2 gene expression and restored protein levels to control level values. Conclusions: our findings indicate a new mechanism of VD(3) action in the uterine physiology of PCOS rats.