miRNA profiling of granulosa cell-derived exosomes reveals their role in promoting follicle development.

To explore whether granulosa cell (GC)-derived exosomes (GC-Exos) and follicular fluid-derived exosomes (FF-Exos) have functional similarities in follicle development and to establish relevant experiments to validate whether GC-Exos could serve as a potential substitute for follicular fluid-derived exosomes to improve folliculogenesis. GC-Exos were characterized. MicroRNA (miRNA) profiles of exosomes from human GCs and follicular fluid were analyzed in depth. The signature was associated with folliculogenesis, such as phosphatidylinositol 3 kinases-protein kinase B signal pathway, mammalian target of rapamycin signal pathway, mitogen-activated protein kinase signal pathway, Wnt signal pathway, and cyclic adenosine monophosphate signal pathway. A total of five prominent miRNAs were found to regulate the above five signaling pathways. These miRNAs include miRNA-486-5p, miRNA-10b-5p, miRNA-100-5p, miRNA-99a-5p, and miRNA-21-5p. The exosomes from GCs and follicular fluid were investigated to explore the effect on folliculogenesis by injecting exosomes into older mice. The proportion of follicles at each stage is counted to help us understand folliculogenesis. Exosomes derived from GCs were isolated successfully. miRNA profiles demonstrated a remarkable overlap between the miRNA profiles of FF-Exos and GC-Exos. The shared miRNA signature exhibited a positive influence on follicle development and activation. Furthermore, exosomes derived from GCs and follicular fluid promoted folliculogenesis in older female mice. Exosomes derived from GCs had similar miRNA profiles and follicle-promoting functions as follicular fluid exosomes. Consequently, GC-Exos are promising for replacing FF-Exos and developing new commercial reagents to improve female fertility.

Effect of BMI on cumulative live birth rates in patients that completed IVF treatment: a retrospective cohort study of 16,126 patients.

Although several studies have reported that high maternal BMI could influence the cumulative live birth rate (CLBR) in fresh embryo transfer cycles, the association of BMI with CLBR remains unclear in patients that completed IVF treatment. In this study, we examined the association of maternal BMI with CLBR, including repetitive one oocyte pick-up (OPU) and all fresh and frozen embryo transfer until live birth or embryos were run out. A total of 16,126 patients' data were included in the analysis and were divided into four groups based on BMI. We found that patients' characteristics, embryo parameters, and pregnancy outcomes differed among different BMI groups. Multivariate logistic regression showed that being underweight was associated with a higher possibility of having live birth than the reference group (OR (95% CI) 1.40 (1.22-1.59), P < 0.001), whereas being overweight and obese were associated with a lower possibility of having live birth than the reference group ((OR (95% CI) 0.81 (0.74-0.90), P < 0.001) and (OR (95% CI) 0.68 (0.55-0.85), P < 0.001)). After adjustment for confounding factors, the reference group was associated with a higher possibility of having live birth, with a significant difference found between the obese and reference groups (OR (95% CI) 0.55 (0.43-0.70), P < 0.001). An association was found between CLBR and BMI, indicating that an increase in BMI results in a decline in CLBR. Moreover, the CLBR of patients with different characteristics differed in the various BMI groups. Taken together, our data show that maternal BMI has a significant impact on CLBR.

Meiosis resumption in human primordial germ cells from induced pluripotent stem cells by in vitro activation and reconstruction of ovarian nests.

BACKGROUND: The differentiation of human induced pluripotent stem cells (iPSCs) into oocytes, which involves the transformation from mitosis to meiosis, has been a hotspot of biological research for many years and represents a desirable experimental model and potential strategy for treating infertility. At present, studies have shown that most cells stagnate in the oogonium stage after differentiation into primordial germ cells (PGCs) from human iPSCs. METHODS: iPSCs carrying a SYCP3-mkate2 knock-in reporter were generated by the CRISPR/Cas9 strategy to monitor meiosis status during induced differentiation from iPSCs into oocytes. These induced PGCs/oogonia were activated by small molecules from the Wnt signaling pathway and then cocultured with reconstructed human ovarian nests in vivo for further development. RESULTS: First, human PGCs and oogonia were efficiently induced from iPSCs. Second, induced dormant PGCs resumed meiosis and then differentiated into primary oocytes through the in vitro activation of the Wnt signaling pathway. Finally, a new coculture system involving the reconstruction of ovarian nests in vitro could facilitate the differentiation of oocytes. CONCLUSIONS: Human PGCs/oogonia induced from iPSCs can be activated and used to resume meiosis by molecules of the Wnt signaling pathway. The coculture of activated PGCs and reconstruction of ovarian nests facilitated differentiation into primary oocytes and the generation of haploid human oocytes in vivo. These findings established a new strategy for germline competence in primary oocytes and provided a keystone for human gametogenesis in vitro and in vivo.