Mutant ZP1 in familial infertility.

The human zona pellucida is composed of four glycoproteins (ZP1, ZP2, ZP3, and ZP4) and has an important role in reproduction. Here we describe a form of infertility with an autosomal recessive mode of inheritance, characterized by abnormal eggs that lack a zona pellucida. We identified a homozygous frameshift mutation in ZP1 in six family members. In vitro studies showed that defective ZP1 proteins and normal ZP3 proteins colocalized throughout the cells and were not expressed at the cell surface, suggesting that the aberrant ZP1 results in the sequestration of ZP3 in the cytoplasm, thereby preventing the formation of the zona pellucida around the oocyte.

Polychlorinated biphenyls impair endometrial receptivity in vitro via regulating mir-30d expression and epithelial mesenchymal transition.

Polychlorinated biphenyls (PCBs) are ubiquitous legacy persistent pollutants and epidemiological data showed that PCB burdens were associated with failed implantation in human. However, the mechanism how PCB exposure affects the embryo implantation is not clear. Using an in vitro model for human embryo implantation employing the human choriocarcinoma cell line JAR and the human endometrial cell line Ishikawa, we have shown that PCB mixture Aroclor 1254 at environmental-relevant concentrations (2.5, 12.5, and 62.5µM) dose-dependently impaired the endometrial receptivity by reducing the adhesion of JAR spheroid attachment and increasing the spheroid outgrowth. The receptive-up-regulated micro-RNA, mir-30d was also down-regulated in endometrial cells by the exposure. Following transient transfection of mir-30d mimic, the disrupted attachment and outgrowth of JAR spheroids was partially restored in the model. By measurement of cadherin switch and vimentin expression, the PCB exposure also activated epithelial mesenchymal transition (EMT) in endometrial cells. In accordance, mir-30d mimic suppressed the EMT markers induced by PCBs. Luciferase reporter assay confirmed that the EMT regulator Snai1 was targeted by mir-30d, and the expression of Snai1 was dose-dependently up-regulated by PCB exposure. Taken together, our study revealed that PCBs may affect the receptivity of endometrial cells by impairing the interaction between receptivity-up-regulated microRNA and EMT process.

Non-coding RNA LINC00473 mediates decidualization of human endometrial stromal cells in response to cAMP signaling.

Decidualization is an essential step in the establishment of pregnancy. However, the functional contributions of long intergenic noncoding RNAs (LincRNAs) to decidualization have not been explored. To explore the regulation and role of LincRNAs during human decidualization, human endometrial stromal cells (HESCs) are induced to undergo in vitro decidualization by treating with estradiol-17ß, db-cAMP and medroxyprogesterone acetate. LINC00473 (LINC473) expression is highly induced in HESCs after decidual stimulus. We found that cAMP-PKA pathway regulates the expression of LINC473 through IL-11-mediated STAT3 phosphorylation. RNA interference-mediated down-regulation of LINC473 inhibits in vitro decidualization. These results suggested that LINC473 might be functionally required for human decidualization. This is the first report demonstrating the presence of LincRNA during human decidualization.

Decrease in prosaposin in spermatozoon is associated with polychlorinated biphenyl exposure.

Polychlorinated biphenyls (PCBs) are a class of ubiquitous persistent organic pollutants and they have been associated with declining male fertility. In the present study, we aimed to determine the responsiveness of prosaposin (Psap) expression to PCB exposure. Male C57 mice were exposed to PCB mixture (Aroclor 1254) of environmental related doses by oral gavage. After exposure for 50 days, the expression of Psap was significantly decreased by PCB exposure in epididymides and epydidymal spermatozoa, but not in testis. The Psap abundance in sperm was decreased in a dose-dependent manner. Benchmark dose modeling revealed the 95% lower confidence limit on the benchmark dose (BMDL) and Benchmark Dose (BMD) for Psap reduction were 1.25 and 8.89 µg/kg Aroclor 1254, and for sperm motility reduction were 11.85 and 61.9 µg/kg Aroclor 1254. The depressed Psap level also showed a significant correlation (P<0.01, r=-0.531) with PCB accumulation in liver. In men with detectable PCB exposure in semen, Psap expression in sperm was significantly decreased whereas the semen parameters were unaffected. Linear regression showed that a negative association between total PCB level in seminal plasma and Psap level in ejaculated spermatozoa (P<0.05, r=-0.396). In conclusion, our data suggested that the abundance of Psap in sperm sample may be a sensitive endpoint to predict PCB exposure.

Differential expression and anti-oxidant function of glutathione peroxidase 3 in mouse uterus during decidualization.

Glutathione peroxidase 3 (GPX3) is an important member of antioxidant enzymes for reducing reactive oxygen species and maintaining the oxygen balance. Gpx3 mRNA is strongly expressed in decidual cells from days 5 to 8 of pregnancy. After pregnant mice are treated with GPX inhibitor for 3 days, pregnancy rate is significantly reduced. Progesterone stimulates Gpx3 expression through PR/HIF1α in mouse endometrial stromal cells. In the decidua, the high level of GPX3 expression is closely associated with the reduction of hydrogen peroxide (H2O2). Based on our data, GPX3 may play a major role in reducing H2O2 during decidualization.

The mesenchymal-epithelial transition during in vitro decidualization.

The epithelial-mesenchymal transition plays a critical role in embryonic development, cancer progression, and metastasis. Decidualization is the process by which the fibroblast-like endometrial stromal cells differentiate into polygonal epithelial-like cells. However, it is still unclear whether mesenchymal-epithelial transition (MET) occurs during decidualization. The aim of this study was to examine whether decidualization causes the downregulation of some mesenchymal markers and upregulation of some epithelial markers in cultured uterine stromal cells. We showed that decidualization causes the downregulation of snail and vimentin expression, and upregulation of E-cadherin and cytokeratin expression. During in vitro decidualization, cultured stromal cells lose elongated shape and show epithelium-like characteristics. Our data suggest that the process of MET may exist during decidualization.

Expression and function of fatty acid-binding protein 4 during mouse decidualization.

Fatty acid-binding protein 4 (Fabp4) is highly expressed in the secondary decidual zone of mouse decidua and deciduoma and stromal cells under in vitro decidualization. Dtprp, a well-known marker of in vitro decidualization, is diminished by small interfering RNA against Fabp4 and FABP4 inhibitor and stimulated through Fabp4 overexpression.

Genome-wide identification of micro-ribonucleic acids associated with human endometrial receptivity in natural and stimulated cycles by deep sequencing.

OBJECTIVE: To identify microRNAs (miRNAs) associated with endometrial receptivity. DESIGN: Observational study. SETTING: Medical center. PATIENT(S): Healthy, regularly cycling women undergoing IVF treatment. INTERVENTION(S): Gonadotropin stimulation and endometrial biopsy. MAIN OUTCOME MEASURE(S): Quantification of miRNA expression profiles by deep sequencing. RESULT(S): The miRNA expression profiles in human endometrium on days LH+2 and LH+7 (LH = 0 is the day of the LH surge) in natural cycles as well as on days hCG+4 and hCG+7 (hCG = 0 is the day of hCG injection) in stimulated cycles were determined by deep sequencing. In natural cycles, there were 20 significantly changed miRNAs in human endometrium on LH+7 compared with LH+2. These miRNAs were predicted to target a large set of genes with different functions, including cell cycle, transport, cell adhesion, cell death, and metabolism. In stimulated cycles, 22 miRNAs were significantly dysregulated on hCG+7 in comparison with LH+7, 11 of which exhibited putative estrogen response elements or P response elements in the promoters. Additionally, unsupervised hierarchical clustering analysis demonstrated that the miRNA expression profile on hCG+4 was similar to that on LH+7, suggesting that ovarian stimulation may alter the window of endometrial receptivity. CONCLUSION(S): MiRNAs may be novel biomarkers for human endometrial receptivity and may help optimize the protocol for IVF treatment.