Effect of a short-term vitamin E supplementation on oxidative stress in infertile PCOS women under ovulation induction: a retrospective cohort study.

BACKGROUND: Vitamin E, which is critically important in the whole process of reproduction, can antagonize the oxidative stress caused by the oxygen free radicals and antioxidant imbalance and regulate normal physiological function of the reproductive system. The effect of short-term supplementation of vitamin E on outcomes of infertile women with polycystic ovary syndrome (PCOS) when they underwent ovulation induction with clomiphene citrate (CC) and human menopausal gonadotropin (HMG) remains unknown. METHODS: This was a retrospective cohort clinical trial from October 2015 to April 2017. A total of 321 PCOS cases underwent ovulation induction with CC and HMG. Patients in group A (n = 110) did not receive vitamin E while patients in group B (n = 105) and group C (n = 106) received oral treatment of vitamin E at 100 mg/day during follicular phase and luteal phase, respectively. RESULTS: It was observed no significant differences of ovulation rate, clinical pregnancy rate, and ongoing pregnancy rate among the three groups. It was interesting that dosage of HMG were significant lower in group B compared with those in group A and group C (P<0.05). CONCLUSIONS: A short-term supplementation of vitamin E can improve oxidative stress, and reduce exogenous HMG dosage to lower the economic cost with a similar pregnancy rate in the ovulation induction cycle. However, the supplementation does not alter the pregnancy rate in the ovulation induction cycle. TRIAL REGISTRATION: ChiCTR-OOC-14005389, 2014.

Tyrosine nitrations impaired intracellular trafficking of FSHR to the cell surface and FSH-induced Akt-FoxO3a signaling in human granulosa cells.

Many infertile women suffered from poor ovarian response, and increased reactive oxygen species with age might mediate the poor ovarian response to FSH. In this study, we collected follicular fluids and isolated granulosa cells from female patients. Increased levels of peroxynitrite, tyrosine nitrations of FSH receptor (FSHR) and apoptosis were obviously detectable with decreased FSHR protein expressions in granulosa cells of the poor ovarian responders. In KGN (a human ovarian granulosa cell line) cells, exogenous peroxynitrite could sequester FSHR in the cytoplasm, and these dislocated FSHR might suffer from proteasome-mediated degradations. Here, we identified four peroxynitrite-mediated nitrated tyrosine residues of FSHR. Site-directed mutagenesis of FSHR revealed that Y626 was pivotal for intracellular trafficking of FSHR to the cell surface. Akt-induced inactivation of FoxO3a was required for the repression of FSH on granulosa cell apoptosis. However, peroxynitrite impaired FSH-induced Akt-FoxO3a signaling, while FSHR-Y626A mutant took similar effects. In addition, FoxO3a knockdown indeed impaired FSH-mediated cell survival, while FoxO3a-S253A mutant reversed that significantly.