Effect of different endometrial preparation methods on pregnancy outcome of FET in women with a normal menstrual cycle.

Objective: This study aims to explore the relationship between different endometrial preparations and pregnancy outcomes among patients with regular ovulatory cycles in order to find the best endometrial preparation methods in the freeze-thaw embryo transfer (FET) cycle. Materials and Methods: This is a retrospective study to investigate FET pregnancy outcomes in women who had a regular menstrual cycle, were younger than 35 years old, and underwent a modified natural cycle (mNC), ovulation induction (OI), or a hormone replacement treatment (HRT) cycle. A total of 1071 frozen cycles were included for analysis. Results: The implantation rate and live birth rate (LBR) in the OI group show a significant difference when compared to the mNC and HRT groups (P < 0.01). After adjusting for confounding factors, the logistic regression analysis revealed that the number of embryos transferred, the embryo stage, and quality were significantly associated with clinical pregnancy rate and LBR. The LBR was additionally affected by the mode of the endometrial preparation; the OI cycle could increase LBR. Conclusions: Endometrial preparation methods affect the LBR in women with a regular menstrual cycle. The OI cycle had an advantage in the LBR of FET.

Effect of bromodomain PHD-finger transcription factor (BPTF) on trophoblast epithelial-to-mesenchymal transition.

The trophoblast epithelial-to-mesenchymal transition (EMT) is a procedure related to embryo implantation, spiral artery establishment and fetal-maternal communication, which is a key event for successful pregnancy. Inadequate EMT is one of the pathological mechanisms of recurrent miscarriage (RM). Whole-exome sequencing revealed that the mutation of bromodomain PHD-finger transcription factor (BPTF) was strongly associated with RM. In the present study, the effects of BPTF on EMT and the underlying mechanism were investigated. We found that the expression of BPTF in the villi of RM patients was significantly downregulated. Gene Ontology (GO) analysis revealed that BPTF participated in cell adhesion. The knockdown of BPTF prevented EMT and attenuated trophoblast invasion in vitro. BPTF activated Slug transcription by binding directly to the promoter region of the Slug gene. Interestingly, the protein levels of both Slug and BPTF were decreased in the villous cytotrophoblasts (VCTs) of RM villi. In conclusion, BPTF participates in the regulation of trophoblast EMT by activating Slug expression, suggesting that BPTF defects are an important factor in RM pathogenesis.

The Prl3d1-Cre mouse line selectively induces the expression of Cre recombinase in parietal trophoblast giant cells.

The placenta plays a pivotal role in the maintenance of normal pregnancy, but how it forms, matures, and performs its function remains poorly understood. Here, we describe a novel mouse line (Prl3d1-iCre) that expresses iCre recombinase under the control of the endogenous prl3d1 promoter. Prl3d1 has been proposed as a marker for distinguishing trophoblast giant cells (TGCs) from other trophoblast cells in the placenta. The in vivo efficiency and specificity of the Cre line were analyzed by interbreeding Prl3d1-iCre mice with B6-G/R reporter mice. Through anatomical studies of the placenta and other tissues of Prl3d1-iCre/+; B6-G/R mouse mice, we found that the tdTomato signal was expressed in parietal trophoblast giant cells (P-TGCs). Thus, we report a mouse line with ectopic Cre expression in P-TGCs, which provides a valuable tool for studying human pathological pregnancies caused by implantation failure or abnormal trophoblast secretion due to aberrant gene regulation.

Putrescine alleviates the oxidative damage of cumulus-oocyte complex via improving fatty acid oxidation.

BACKGROUND: Fatty acid oxidation of cumulus-oocyte complex (COC) provides sufficient energy for oocyte maturation. But, the relationship between fatty acid oxidation and oxidative stress in aging follicles, as well as the effect of putrescine, is still unclear. METHODS: The porcine COCs were randomly divided into four groups and cultured in in vitro maturation (IVM) medium with or without 1 mmol/L putrescine, with 50 µmol/L hydrogen peroxide (H2O2) or with 50 µmol/L H2O2 plus 1 mmol/L putrescine. Oocyte maturation was assessed by the first polar body extrusion. The expressions of genes involved in fatty acid oxidation were detected, and the mitochondrial function was analyzed by themembrane potential. RESULTS: The maturation rate of oocyte was significantly lower in the H2O2 group when compared with the control group (P＜0.001), and putrescine significantly increased this rate in the H2O2 plus putrescine group when compared with the H2O2 group (P＜0.001). The expressions of LKB1, STRAD, ACC2, AMPKα1 and AMPKα2 mRNAs in cumulus cells (CCs) were significantly downregulated by H2O2 treatment, and partly rescued by putrescine addition (P＜0.05-0.001). However, the changes of LKB1, STRAD, ACC2, AMPKα1 and AMPKα2 mRNAs in oocytes were inapparent. The mitochondrial membrane potential of CCs in the H2O2 group was significantly lower than that in the control group, while putrescine addition significantly increased the mitochondrial membrane potential (P＜0.001). CONCLUSION: The decrease of oocyte maturation due to oxidative stress is related with the decreased fatty acid oxidation, and putrescine may alleviate the COCs damage via improving fatty acid oxidation.

Alpha-enolase 1 knockdown facilitates the proliferation and invasion of villous trophoblasts by upregulating COX-2.

BACKGROUND: Enolase 1 (ENO1) is a metabolic enzyme which participates in pyruvate synthesis and ATP production in cells. Previously, differential expression of ENO1 was discovered in villous tissues between recurrent miscarriage and induced abortion. This study was designed to explore whether ENO1 influences the proliferation and invasion of villous trophoblasts and the related molecular mechanisms. METHODS: First, ENO1 expression in placental villus tissues collected from recurrent miscarriage (RM) patients and women for induced abortion as well as in trophoblast-derived cell lines was detected by RT-qPCR and western blotting. ENO1 localization and expression in villus tissues were further confirmed through immunohistochemistry staining. Then, the effects of ENO1 downregulation on trophoblast Bewo cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) process were evaluated by CCK-8 assay, transwell assay, and western blotting. As for the regulatory mechanism of ENO1, the expression of COX-2, c-Myc and cyclin D1 in Bewo cells after ENO1 knockdown was finally evaluated by RT-qPCR and western blotting. RESULTS: ENO1 was mainly localized in the cytoplasm, with very small amounts in the nucleus of trophoblast cells. ENO1 expression in the villi tissues of RM patients was significantly increased, when compared with the villous tissues of healthy controls. Furthermore, Bewo cells, a trophoblast cell line with relatively higher expression of ENO1, was used to downregulate the ENO1 expression by ENO1-siRNA transfection. ENO1 knockdown significantly facilitated Bewo cell growth, EMT process, migration, and invasion. ENO1 silencing markedly elevated COX-2, c-Myc, and cyclin D1 expression. CONCLUSION: ENO1 may participate in the development of RM via suppressing the growth and invasion of villous trophoblasts via reducing the expression of COX-2, c-Myc, and cyclin D1.

Sphingosine 1-phosphate alleviates radiation-induced ferroptosis in ovarian granulosa cells by upregulating glutathione peroxidase 4.

Ferroptosis is a form of cell death caused by the accumulation of lipid peroxidation products due to abnormal iron metabolism. However, it remains unknown whether ferroptosis participates in the process of radiation-induced ovarian injury. Sphingosine-1-phosphate (S1P) is an important bioactive sphingolipid that has a protective effect on ovarian injury. The present study aims to determine whether X-ray radiation induces ferroptosis in the ovarian granulosa KGN cell line, and explore the potential effect of S1P and its mechanism in radiation-induced ferroptosis. The results indicated that irradiation reduced the viability of KGN cells, altered the mitochondrial morphology, induced the intracellular accumulation of iron ions, increased oxidative stress, and induced lipid peroxidation. Furthermore, the radiation exposure triggered the ferroptosis in KGN cells. S1P can alleviate radiation-induced ferroptosis. Furthermore, the protective effect of S1P was reversed after the application of siRNA to interfere with the glutathione peroxidase 4 expression. Ferroptosis might be pervasive in radiation-induced ovarian injury, and S1P may serve as a potential therapeutic approach to protect against the toxic effect of radiation in female gonads by inhibiting ferroptosis.

Blood nesfatin-1 levels in patients with polycystic ovary syndrome: a systematic review and meta-analysis.

Background: Previous studies have investigated the relationship between nesfatin-1 level and polycystic ovary syndrome (PCOS). However, these studies have produced conflicting results. Thus, in this meta-analysis, we aimed to clarify the association between blood nesfatin-1 levels and PCOS, and the ability of nesfatin-1 as a biomarker in PCOS. Methods: Meta-analysis was performed using STATA 12.0 software. We computed standard mean difference (SMD) and 95% confidence interval (CI) regarding the comparison of blood nesfatin-1 in patients with PCOS and controls. Results: The present meta-analysis showed no significant difference in blood nesfatin-1 level between patients with PCOS and controls with a random effects model (SMD = 0.03; 95%CI: -0.71, 0.77; I2 = 97.1%, p value for Q test < 0.001). Subgroup analysis for different ethnicities reported no significant difference in blood nesfatin-1 level between patients with PCOS and controls in both Caucasian and Asian populations. Subgroup analysis for different sample types reported no significant difference in serum nesfatin-1 level between patients with PCOS and controls. Subgroup studies reported no significant difference in blood nesfatin-1 level between PCOS and controls in both obese and non-obese populations. Conclusion: In conclusion, there is no significant relationship between blood nesfatin-1 levels and PCOS.

Effect of ovulation before or after intrauterine insemination on pregnancy outcome in patients with unexplained infertility or polycystic ovarian syndrome.

OBJECTIVE: To investigate the relationship between ovulation and pregnancy outcomes in patients undergoing intrauterine insemination (IUI). METHODS: The clinical data from 784 patients, diagnosed with polycystic ovarian syndrome (PCOS) or unexplained infertility, underwent 1624 IUI cycles were analyzed retrospectively. Ovulation was observed by transvaginal ultrasonography on the day of IUI. The clinical pregnancy rate (CPR), abortion rate (AR), and live birth rate (LBR) were analyzed. RESULTS: The study included 1031 pre-ovulation IUI cycles (63.49%) and 593 post-ovulation IUI cycles (36.51%). The CPR was 13.05%, the AR was 15.57%, and the LBR was 11.02%. Ovulation before or after IUI affected the CPR (11.06% VS 16.53%, p = .002) and LBR (9.41% VS 13.83%, p = .006) per cycle, but did not affect the AR (14.91% VS 16.33%, p = .149). The sex ratio of children was not related to ovulation (p = .948). After adjusting for baseline characteristics and logistic regression, the CPR (OR = 1.931, 95% CI 1.062-1.931, p = .019) and LBR (OR = 1.389, 95% CI 1.007-1.916, p = .045) of post-ovulation insemination were higher than those of pre-ovulation insemination significantly. CONCLUSION: Pregnancy outcomes were affected by ovulation on the day of IUI in patients with unexplained infertility or PCOS. Post-ovulation insemination may improve the CPR of IUI.

Predictors of pregnancy after intrauterine insemination in women with polycystic ovary syndrome.

OBJECTIVE: To evaluate the effects of body mass index (BMI) in patients with polycystic ovary syndrome (PCOS) undergoing controlled ovarian stimulation (COS) with intrauterine insemination (IUI). METHODS: This retrospective study evaluated couples with PCOS undergoing COS and IUI. The relationship between cumulative IUI pregnancy outcomes and BMI, treatment cycles, treatment schemes, number of dominant follicles, endometrial thickness, infertility duration and type of infertility was analysed. RESULTS: The study evaluated 831 IUI cycles in 451 couples with PCOS. Compared with normoweight women, overweight and obese women required more human menopausal gonadotropin (hMG) doses and more days of COS. Gestational diabetes mellitus occurred more frequently in the obese group than in the other BMI groups. The clinical pregnancy and live birth rates in the hMG, clomiphene citrate (CC) + hMG and letrozole (LE) + hMG groups were significantly higher than those in the CC and LE groups. The clinical pregnancy rate was higher in the secondary infertility group compared with the primary infertility group. CONCLUSION: Obese women might require more hMG doses and more days of COS to overcome the effects of weight. As BMI increases, the incidence of gestational diabetes might also increase. The number of cycles and type of infertility may have a predictive value for pregnancy outcomes.

Down-regulation of the Sp1 transcription factor by an increase of microRNA-4497 in human placenta is associated with early recurrent miscarriage.

BACKGROUND: The pathophysiological mechanism of recurrent miscarriage (RM) is unclear. The goals of this study were to determine the role of microRNA-4497 overexpression in placental villus tissues in early RM; To identify the potential target mRNAs of miRNA-4497; And to investigate the microRNA-4497-mediated regulatory mechanisms in placental trophoblasts. METHODS: Bioinformatics analysis was performed to identify the candidate target genes of miRNA-4497. The protein expression of Sp1 transcription factor (SP1), chemokine (C-X-C motif) receptor 5 (CXCR5) and bone morphogenetic protein 8a (BMP8A) were determined in the villus tissues of the RM and normal groups by Western blotting and immunohistochemistry. Cultured 293T cells were co-transfected with the miRNA-4497 agomir or luciferase reporter vectors containing the wild-type or mutant 3'-UTRs of the target mRNAs to verify the regulatory role of miRNA-4497. RESULTS: Bioinformatics analysis suggested that SP1, CXCR5 and BMP8A mRNAs are potential targets of miRNA-4497. The expression of SP1, CXCR5 and BMP8A proteins in the chorionic villus tissues of RM placentas were significantly decreased compared to those in the normal controls. Moreover, SP1 protein levels were inversely correlated with the levels of miRNA-4497 in the placentas of RM patients and normal controls. The expression of SP1 mRNA and protein were down-regulated in HTR-8/SVneo cells after forced overexpression of the miRNA-4497 agomir. The results of the co-transfection assay showed that mutation of the miRNA-4497-binding sites in the 3'-untranslated region (3'-UTR) of SP1 led to a recovery of luciferase activity upon overexpression of miRNA-4497, suggesting that SP1 could be a direct target of miRNA-4497. CONCLUSIONS: An increased miRNA-4497 level in the placental villus tissues associated with recurrent miscarriage may down-regulate SP1 expression. The negative regulation of SP1 by miRNA-4497 may potentially contribute to the pathogenesis of recurrent miscarriage through promotion of trophoblast apoptosis. These findings provide novel information on the regulation of placental trophoblast apoptosis, and could be useful for the development of new therapeutic strategies for better management of recurrent miscarriage.

Pregnancy predictors in unexplained infertility after intrauterine insemination.

BACKGROUND: Intrauterine insemination (IUI) is a first-line treatment for unexplained infertility (UI). There was a compelling need for the improvement of pregnancy rate in females with UI. OBJECTIVE: To explore the pregnancy predictors in cases of UI undergoing IUI. METHOD: A total of 212 couples who underwent 446 IUI cycles were involved the study. Different factors were grouped to explore the influencing factors of IUI for UI. RESULT: Female age and somking affected pregnancy outcomes. As the number of treatment cycles increased, the pregnancy rate increased. The BMI, treatment regimens, type of infertility, endometrium, and timing insemination have no significant prognostic value. CONCLUSION: Apart from the number of treatment cycles, somking, and female age, no other factors had prognostic value. More studies and samples are necessary to evaluate whether other factors affect conception.

Association of vascular endothelial growth factor polymorphisms with polycystic ovarian syndrome risk: a meta-analysis.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a multi-gene hereditary disorder caused by the interaction of certain gene variation with environmental factors. Previous studies have shown that vascular endothelial growth factor (VEGF) gene polymorphisms are associated with the risk of polycystic ovarian syndrome. However, the results of these studies remain controversial. We performed the present meta-analysis aiming to further investigate the potential relationship between VEGF polymorphisms and susceptibility to PCOS. METHODS: The following databases were systematically searched: PubMed, EMBASE, Web of Science (WOS), China National Knowledge Infrastructure (CNKI), and Wanfang Databases. The correlation between VEGF polymorphisms and PCOS risk was assessed by calculating pooled odds ratios (ORs) and their 95% confidence intervals (95% CIs). Subgroup analyses stratified by ethnicity and source of control were also conducted. Besides, trial sequential analysis (TSA) was done to verify the reliability of the pooled results. RESULTS: 10 relevant case-control studies were incorporated in this meta-analysis, involving 1347 PCOS cases and 1378 controls. The VEGF rs2010963 polymorphism was associated with decreased PCOS risk in the whole population and the Asian populations. The VEGF rs3025039 polymorphism was associated with decreased PCOS susceptibility and the Asian populations, but increased risk of PCOS was observed among the Caucasian populations. In addition, the results of trial sequential analysis (TSA) showed the negative correlation between rs2010963 and PCOS risk, obtained by our meta-analysis, was stable and reliable. CONCLUSION: Overall, different VEGF gene polymorphisms may exert different effects on PCOS susceptibility. The VEGF rs2010963 polymorphism decreases PCOS susceptibility in both the whole population and the Asian populations, and VEGF rs3025039 polymorphism causes lower PCOS susceptibility in the whole population and the Asian populations but higher in the Caucasian populations.

Differential expression profile of long noncoding RNAs in human chorionic villi of early recurrent miscarriage.

Miscarriage is the spontaneous loss of a pregnancy before the fetus reaching viability, including all pregnancy losses from the time of conception until 24weeks of gestation. Three or more times of consecutive spontaneous miscarriages is defined as recurrent miscarriage (RM). The underlying causes cannot be confirmed in nearly 50% of RM patients. We investigated the differential expression of long noncoding RNAs (lncRNAs) in chorionic villi tissues of RM patients compared with normal women, and their possible involvement in the pathogenic pathways leading to RM. A total number of 1449 differentially expressed lncRNAs were identified from chorionic villi tissues of RM patients compared to normal women. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed that these differentially expressed lncRNAs were involved in 26 biological pathways including 11 up-regulated and 15 down-regulated ones. Functional analysis showed that pathways of endocrine, immunity, ECM-receptor interactions and apoptosis are the major pathogenic mechanisms involved in the development of RM. Characterization of these lncRNAs in different pathways opened a new starting point for further investigating the epigenetic regulation mechanisms of lncRNAs in RM.