No abstract

ObjectivePreviously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD).MethodsWe evaluated the loss-of-function of Tkt by microinjecting Tkt double-stranded RNAs (dsRNAs) into germinal vesicle-stage oocytes, and the oocytes were cultured in vitro to evaluate phenotypic changes during oocyte maturation. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression of other enzymes in the pentose phosphate pathway were determined after Tkt RNA interference (RNAi).ResultsDespite the complete and specific knockdown of Tkt expression, GVBD occurred and meiosis was arrested at the metaphase I (MI) stage. The arrested oocytes exhibited spindle loss, chromosomal aggregation, and declined maturation promoting factor and mitogen-activated protein kinase activities. The modified expression of two enzymes in the pentose phosphate pathway, Prps1 and Rbks, after Tkt RNAi and decreased maturation rates were amended when ribose-5-phosphate was supplemented in the culture medium, suggesting that the Tkt and pentose phosphate pathway are important for the maturation process.ConclusionWe concluded that Tkt and its associated pentose phosphate pathway play an important role in the MI-MII transition of the oocytes' meiotic cell cycle, but not in the process of GVBD.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder found in women. The etiology of PCOS is still not clear, and there are no available studies on the proteome analysis of granulosa cells (GCs) in PCOS patients. To identify the pathogenic mechanisms and potential diagnostic markers for PCOS, we conducted proteomic profiling of GCs in PCOS patients by two-dimensional gel electrophoresis and liquid chromatography coupled with mass spectrometry (LC-MS/MS) analyses. The proteomic analysis yielded eight downregulated and 12 upregulated proteins in PCOS patients, among which apolipoprotein A-I (ApoA-I) showed significant downregulation in PCOS patients as confirmed by Western blotting. Knockdown of ApoA-I decreased the number of transcripts of steroidogenic enzymes in a granulosa cell line (KGN), while its overexpression generally increased the level of expression of these enzymes. Furthermore, modulation of the expression level of ApoA-I in the granulosa cells altered progesterone production. Therefore, this study suggests that ApoA-I can be useful as a granulosa cell biomarker of PCOS patients and that downregulated ApoA-I may be related to the disturbed production of steroid hormones in PCOS patients.

Asherman's syndrome (AS) is characterized by intrauterine adhesion or fibrosis resulting from damage to the endometrium, often leading to amenorrhea, infertility, or recurrent pregnancy loss. Although various therapeutic strategies for AS have been proposed, the options remain limited. New strategies such as bone marrow-derived mesenchymal stem cell (BM-MSC) therapy aim to potentiate the intrinsic capacity of endometrial regeneration. However, BM-MSC therapy has not been widely adopted mainly because it involves invasive and expensive procedures such as bone marrow biopsy and cell storing. On the other hand, platelet-rich plasma (PRP) is considered safe and affordable because it involves the less invasive procedure of blood collection from peripheral veins to produce PRP. To assess the effectiveness of human PRP infusion for endometrial regeneration, we established a murine model of injury-induced AS and evaluated endometrial morphology, expression of fibrosis-related factors, implantation sites (IS), and pregnancy outcomes associated with human PRP treatment. We found that treatment with human PRP was associated with improved endometrial morphology, reduced degree of fibrosis, and down-regulated expression of fibrosis-related factors in murine model of AS. Furthermore, human PRP treatment was associated with a higher number of IS and live-births. Our results suggest that human PRP treatment may become a valuable strategy to promote the regeneration of damaged endometrium and thus improve fertility and pregnancy outcomes in clinical practice.