Ovarian dysfunction in women with Turner syndrome

Ovarian dysfunction is one of the most common features of women with Turner syndrome. In these women, oocyte apoptosis is markedly accelerated from the early stage of fetal life. Reduction in the number of germ cells disturbs primordial follicle development and thereby leads to the formation of streak gonads. There are three possible causes of accelerated germ cell loss in 45,X ovaries. First, chromosomal pairing failure due to X chromosomal aneuploidy is believed to induce meiotic arrest. Indeed, it has been suggested that the dosage of the X chromosome is more critical for the survival of the oocytes than for other cells in the ovary. Second, impaired coupling between oocytes and granulosa cells may also contribute to germ cell apoptosis. Previous studies have shown that 45,X ovaries may tend to lose tight junctions which are essential for intercellular interactions. Lastly, ovarian dysfunction in women with Turner syndrome is partly attributable to the reduced dosage of several genes on the X chromosome. Specifically, BMP15, PGRMC1, and some other genes on the X chromosome have been implicated in ovarian function. Further studies on the mechanisms of ovarian dysfunction are necessary to improve the reproductive outcomes of women with Turner syndrome.

Ginsenoside Rb1 protects porcine oocytes against methylglyoxal damage thus it improves the quality of parthenogenetic activation and in vitro fertilization embryos

Panax ginseng, a functional food, has been widely used as an edible nourishment and medicinal supplement. Ginsenoside Rb1 is a major bioactive ingredient of ginseng, which shows very specific anti-apoptosis and anti-oxidant activities. Methylglyoxal (MGO) is one of intermediate products of glucose metabolism, which is absorbed easily from high sugar foods or carbonated beverages. It may involve in a variety of detrimental processes in vivo. However, it has not been fully explored the effects of ginsenoside Rb1 on MGO-induced oocytes damage. This study found that MGO-induced DNA damage and mitochondrial dysfunction result in the failure of porcine oocytes maturation and low in vitro development capacity of parthenogenetic activation (PA) and in vitro fertilization (IVF) embryos. Conversely, Rb1 supplementation recovered the rate of maturation, and improved in vitro development capacity of PA and IVF embryos. Rb1 also provided porcine oocytes a lower level of reactive oxygen species production, higher level of ATP content and mitochondrial membrane potential, and stimulated pluripotency gene expression in blastocysts. The findings of this study reveal ginsenoside Rb1 protects porcine oocyte from the cytotoxicity effects of methylglyoxal and provides novel perspectives for the protection of reproduction system by functional food of ginseng.