The mechanisms and functions of microRNAs in mediating the fate determinations of human spermatogonial stem cells and Sertoli cells.

Human spermatogonial stem cells (SSCs) and Sertoli cells might have the applications in reproduction and regenerative medicine. Abnormal spermatogenesis results in male infertility, which seriously affects human reproduction and health. Spermatogenesis depends on the epigenetic and genetic regulation of male germ cells and somatic cells. A number of microRNAs (miRNAs) have been identified in human testicular tissues, and they are closely related to male fertility. Significantly, we and peers have recently demonstrated that numerous miRNAs are essential for regulating the self-renewal and apoptosis of human SSCs and Sertoli cells through controlling their mRNA and lncRNA targets. In this review, we critically discuss these findings regarding the important functions and mechanisms of miRNAs in mediating the fate determinations of human SSCs and Sertoli cells. Meanwhile, we illustrate the regulatory networks for miRNAs by forming the upstream and downstream regulators of mRNAs and lncRNAs in human SSCs, and we address that miRNAs regulate the decisions of Sertoli cells by targeting genes and via N6-methyladenosine (m6A). We also point out the future directions for further studies on this field. This review could offer an update on novel molecular targets for treating male infertility and new insights into epigenetic regulation of human spermatogenesis.

Impact of body mass index (BMI) on the success rate of fresh embryo transfer in women undergoing first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.

OBJECTIVE: To investigate the impact of body mass index (BMI) on the success rate and prenatal outcomes of fresh embryo transfer in women undergoing their first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. METHODS: It is a post-hoc analysis of a prospective observational cohort study. 2569 Chinese women were grouped in quintiles of BMI and according to the official Chinese classification of body weight. IVF/ICSI and pregnancy outcomes were compared between groups. RESULTS: BMI was not associated with IVF/ICSI pregnancy outcomes including hCG positive rate, clinical pregnancy rate, implantation rate, ectopic pregnancy rate, ongoing pregnancy rate, early miscarriage rate, and live birth rate. However, it was negatively related to some pregnancy complications such as gestational diabetes mellitus (GDM) and hypertension. Additionally, the proportion of Cesarean-section was increased with BMI. As for prenatal outcomes, the current results showed no statistical difference in the number of male and female newborn, the proportion of low live birth weight (<2500 g), macrosomia (≥4000 g) (both in all live birth and full-term live birth), and premature delivery (<37 weeks). CONCLUSIONS: The current study showed that BMI was not associated with embryo transfer outcomes after fresh embryo transfer in women undergoing their first IVF/ICSI treatment, whereas BMI was associated with GDM and gestational hypertension.

25(OH)VitD and human endocrine and functional fertility parameters in women undergoing IVF/ICSI.

Background: Vitamin D plays an important role in reproduction. Evidence shown that free 25-hydroxyvitamin D (25(OH)VitD) was more accurate than total 25(OH)VitD in reflecting the status of 25(OH)VitD during pregnancy. However, the relationship between free 25(OH)VitD and female fertility parameters has not been reported yet. Therefore, this study aims to compare the correlation of free and total 25(OH)VitD with fertility parameters in infertility females undergoing in vitro fertilization and embryo transfer (IVF-ET) or intracytoplasmic sperm injection (ICSI). Methods: According to the inclusion and exclusion criteria, 2569 infertility patients who received IVF-ET or ICSI treatment for the first time participated in this study. Five milliliter peripheral blood samples of the patients were collected on the day before embryo transfer (ET). Enzyme linked immunosorbent assay (ELISA) kits was used to detect free 25(OH)VitD and total 25(OH)VitD, and clinical information was collected. Spearman's rho was used to evaluate the association between the variables. Results: The median (IQR) of free 25(OH)VitD was 4.71 (4.11-5.31) pg/mL and total 25(OH)VitD was 19.54 (16.52-22.83) ng/m. The correlation between them, however, was week (rho=0.311). Compared to total 25(OH)VitD, free 25(OH)VitD was slightly better correlated with basal follicle-stimulating hormone (FSH) (rho=0.041, P=0.036), basal estradiol (E2) (rho=0.089, P<0.001), anti-Müllerian hormone (AMH) (rho=-0.057, P=0.004), antral follicle count (AFC) (rho=-0.053, P=0.007), E2 (rho=-0.080, P<0.001), number of oocytes retrieval (rho=-0.079, P<0.001) and progesterone (P)/E2 on hCG trigger day (rho=0.081, P<0.001). Conclusions: Overall, there was only a rather weak correlation of free as well as total 25(OH)VitD with human endocrine and functional fertility parameters in women undergoing IVF/ICSI. Neither free nor total 25(OH)VitD seems to play a major role in human embryo implantation.