Reproductive Sciences

Recurrent implantation failure (RIF) is defined when pregnancy failure occurs after two consecutive in vitro fertilization-embryo transfers to the endometrium using at least four high-quality embryos in women. MicroRNAs are well-known function modulators and are involved in many diseases. Recently, studies on microRNA and recurrent pregnancy loss (RPL) have been actively carried out; however, single nucleotide polymorphisms of miRNA in RPL are not well known. Therefore, we set the aim of this study to identify whether polymorphisms in miRNAs that miR-27aA>G, miR-423C>A, miR-449bA>G, and miR-604A>G are risk factors for idiopathic recurrent implantation failure (RIF) in Korean women. Genotyping was assessed with a polymerase chain reaction–restriction fragment length polymorphism assay. We examined polymorphisms in four miRNA genes: miR-27aA>G, miR-423C>A, miR-449bA>G, and miR-604A>G. We found that the miR-27aA>G, miR-449bA>G, and miR-604A>G polymorphisms were significantly associated with a risk of RIF. In addition, the miR-27aA>G and miR-449bA>G polymorphisms were associated with the frequency of implantation failures. Specifically, the miR-449bAG+GG genotype was associated with RIF prevalence (total RIF: adjusted odd ratio [AOR] = 1.584, 95% CI = 1.008–2.490, P = 0.046; IF ≥ 3 group: AOR = 1.747, 95% CI = 1.088–2.803, P = 0.021; IF ≥ 4: AOR = 1.932, 95% CI = 1.122–3.327, P = 0.018). Based on these results, the miR-449b A>G may be a predisposing factor to RIF susceptibility. However, the mechanism underlying the function of miR-449b A>G in RIF remains to be determined and further studies are needed to improve understanding of the roles of miR-449b A>G, using a larger and more heterogeneous cohort.

Androgen is known to regulate microRNA-135a (miR-135a) and can be regulated by androgen, suggesting that it may contribute to polycystic ovary syndrome (PCOS) with hyperandrogenism. However, its roles and mechanisms of action in PCOS are unknown. In this study, the role and molecular mechanisms underlying miR-135a in granulosa cells (GCs) in PCOS were evaluated. miR-135a expression was upregulated in patients with PCOS and in GCs isolated from patients compared with that in the respective controls (P < 0.01), as determined by RT-qPCR. The overexpression of miR-135a inhibited GC proliferation and induced GC apoptosis, as observed by CCK-8 assay and apoptosis assay. Furthermore, miR-135a overexpression increased the expression of double-strand break maker, γH2AX, as confirmed by western blotting. Our results further suggest that these effects were mediated via downregulation of vascular endothelial growth factor C (VEGFC), which was identified as a direct target of miR-135a. Moreover, levels of VEGFC and miR-135a expression showed a negative correlation. These findings indicate that miR-135a promotes apoptosis and the DNA damage response in GCs in PCOS, likely via VEGFC signaling. This study provides novel insights into GC dysregulation in PCOS and suggests that miR-135a is a promising therapeutic target for PCOS treatment.

To investigate any change in the ovaries, including early follicular serum follicle-stimulating hormone (FSH) level, total ovarian volume, total antral follicle count, and ovarian stromal blood flow, in patients who had undergone abdominal hysterectomy for benign conditions. Fifteen women with abdominal hysterectomy and conservation of ovaries for benign conditions and who were between 29 and 44 years old were recruited to undergo three-dimensional ultrasound examination with power Doppler to assess total ovarian volume, total antral follicle count, and vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of ovarian stromal blood flow. Serum FSH, estradiol, and progesterone levels were checked on the same day. The results of the assessments were considered taken during the early follicular phase if the estradiol and progesterone levels were basal. Fifteen age-matched healthy women underwent the same assessments on the second day of menstruation. Women with hysterectomy had significantly elevated serum FSH level and lower ovarian stromal blood flow indices, including VI, FI, and VFI, as compared with healthy women. The total antral follicle count and the total ovarian volume were similar between the two groups. These changes may suggest altered ovarian function after hysterectomy.

The purpose of the present study was to compare the permeaiility and regulation of paracellular transport in human cervical cells with those in epithelial cells of other organs. Cervical cells (ECE16–1, Caski, and HT3) were grown on filters, and trans-epithelial electrical conductance (GT) and the permeability to pyranine (PPyr) were determined. Cervical cultures were characterized by high GT (83–125 mS•cm−2 ) and high PPyr (6.2–18•10−6 •sec−1). The GT was not significantly affected by cell density but was increased by 20% by lowering extracellular calcium to 0.45 mmol/L or less. The high values of GT and PPyr and the regulation by extracellular calcium indicate that all three cervical cell lines have “leaky” tight junctional complexes. Addition of extracellular adenosine triphosphate (ATP) at 50 μmol/L to the cervical cultures evoked a biphasic change in GT- that was unique to the cervical cells: an initial increase, followed by a sustained decrease by 30 /o frorn baseline GT. The decrease oj GT- was associated with a decrease in PPyr by 17%, indicating that ATP had an effect on the tight junctional/paracellular permeability. The ATP effect was reversible either by washing or by chemical hydrolysis with ATPse. 1 he non-cervical cell lines all responded to extracellular ATP with a transient increase in GT, but not with the pronounced decrease. The permeability of the paracellular pathway can be regulated in cervical epithelia by mechanisms that may be different frorn those in epithelial cells frorn other organs.

The purpose of this study is to compare the levels of maternal serum pregnancy–associated plasma protein-A at the first trimester in pregnancies complicated by impaired placental diseases, such as preeclampsia (PE), intrauterine fetal growth restriction (IUGR), and gestational hypertension (GH), with those in pregnancies without the development of any of these outcomes to expand the knowledge of how this protein behaves in the different impaired placental diseases. This current work is an observational study based on a prospective cohort. Pregnancy-associated plasma protein-A was measured in 422 patients who had completed maternal-perinatal outcomes. Comparisons of pregnancy characteristics and the biomarker between outcome groups (PE, IUGR, gestational hypertension, and not impaired placental outcomes) were analyzed. PAPP-A MoM in the IUGR (0.8 IQR: 0.6–0.9) and GH groups (0.5 IQR: 0.3–1.4) compared to the PE group (1.06 IQR: 0.66–1.52) was significantly lower (p < 0.005). Pregnant women who developed early-onset PE (1.11 IQR 1.08–1.18) presented significant differences with the IUGR group (0.83 IQR: 0.59–0.98; p = 0.002) and those who developed preterm-PE (1.19 IQR: 0.66–1.58; p = 0.045). The results demonstrate that the levels of PAPP-A at first trimester in the sample of women who developed PE, and specially term-PE, were higher than those in women who developed GH or IUGR. The GH group had the lowest PAPP-A values in this sample of pregnant women. Research in a population with a high prevalence of preeclampsia is still lacking and deserves more extended studies to define if these patients could have different rates of PAPP-A.

This study examined whether renin expression and secretion and plasma angiotensin II (Ang II) levels were altered in adult sheep exposed to antenatal betamethasone. Pregnant sheep received injections of 0.17 mg/kg betamethasone or vehicle, at 80 and 81 days of gestation, and offspring were studied at 6 and 18 months of age. At 6 months, plasma prorenin concentrations were significantly lower in betamethasone animals (4.63 ± 0.64 vs 7.09 ± 0.83 ng angiotensin I/mL/h, P < .01). The percentage of plasma active renin was significantly higher in the betamethasone group (31.93 ± 4.09% vs 18.57 ± 2.79%, P < .01). Plasma and renocortical renin levels were similar in both groups at 18 months, but plasma renin activity was lower than at 6 months. Ang II levels were suppressed by betamethasone. The data indicate that prenatal exposure to betamethasone alters processing and secretion of renin in offspring at 6 months, but that this difference is not apparent at 18 months.

The effects of androgens on the uterus have been poorly studied and they need to be clarified to understand why androgen excess, such as observed in women with polycystic ovary syndrome (PCOS), is a risk factor for the development of endometrial hyperplasia, cancer, and infertility. Thus, uterine histomorphology in a PCOS experimental model was evaluated. Beginning at weaning, female rats were injected daily with dehydroepiandrosterone (DHEA, 6 mg/100 g body weight) or vehicle (sesame oil) for 20 consecutive days. On postnatal day 41 (PND41), DHEA-treated animals showed high serum testosterone levels. In addition, uterine histological analysis showed a significant increase in luminal epithelial height and glandular density without changes in cell proliferation. The thickness of the subepithelial stroma and myometrium also increased in these animals. The effect of DHEA on uterine thickness was accompanied by a significant reduction in cell density in both tissue compartments (subepithelial stroma and myometrium). Cell proliferation was not altered in the myometrium, whereas a decrease in the proliferative activity was seen at PND41 in the subepithelial stroma of DHEA animals. The analysis of the extracellular space showed that the changes in the thickness of the subepithelial stroma and myometrium were related to an increase in the organization of collagen fibers and water imbibition. The latter was associated with higher aquaporin 3 and 8 expression. This study provides evidence to further the understanding of PCOS-associated hyperandrogenism effects on uterine architecture. This could have implications for the regulation of uterine function and the development of uterine lesions.

Preeclampsia (PE) manifested by hypertension and proteinuria complicates 3% to 8% of pregnancies and is a leading cause of fetal–maternal morbidity and mortality worldwide. It may lead to intrauterine growth restriction, preterm delivery, and long-term sequelae in women and fetuses, and consequently cause socioeconomic burden to the affected families and society as a whole. Balanced immune responses are required for the maintenance of successful pregnancy. Although not a focus of most studies, decidual cells, the major resident cell type at the fetal–maternal interface, have been shown to modulate the local immune balance by interacting with other cell types, such as bone marrow derived-immune cells, endothelial cells, and invading extravillous trophoblasts. Accumulating evidence suggests that an imbalanced innate immunity, facilitated by decidual cells, plays an important role in the pathogenesis of PE. Thus, this review will discuss the role of innate immunity and the potential contribution of decidual cells in the pathogenesis of PE.