Body mass index in relation to extracellular vesicle-linked microRNAs in human follicular fluid.

OBJECTIVE: To study whether increased body mass index is associated with altered expression of extracellular vesicle microRNAs (EV-linked miRNAs) in human follicular fluid. DESIGN: Cross-sectional study. SETTING: Tertiary-care university-affiliated center. PATIENT(S): One hundred thirty-three women undergoing in vitro fertilization (IVF) were recruited from January 2014 to August 2016. INTERVENTIONS(S): None. MAIN OUTCOME MEASURE(S): EV-linked miRNAs were isolated from follicular fluid and their expression profiles were measured with the use of the Taqman Open Array Human miRNA panel. EV-linked miRNAs were globally normalized and inverse-normal transformed. Associations between body mass index (BMI) and EV-linked miRNA outcomes were analyzed by means of multivariate linear regression and principal component analysis. RESULT(S): Eighteen EV-linked miRNAs were associated with an increase in BMI after adjusting for age, ethnicity, smoking status, and batch effects. Hsa-miR-328 remained significant after false discovery rate adjustments. Principal component analyses identified the first principal component to account for 40% of the variation in our EV-linked miRNA dataset, and adjusted linear regression found that the first principal component was significantly associated with BMI after multiple testing adjustments. Using Kyoto Encyclopedia of Genes and Genomes enrichment analyses, we predicted gene targets of EV-linked miRNA in silico and identified PI3K-Akt signaling, ECM-receptor interaction, focal adhesion, FoxO signaling, and oocyte meiosis pathways. CONCLUSION(S): These results show that a 1-unit increase in BMI is associated with altered follicular fluid expression of EV-linked miRNAs that may influence follicular and oocyte developmental pathways. Our findings provide potential insight into a mechanistic explanation for the reduced fertility rates associated with increased BMI.

Maternal Phthalate and Personal Care Products Exposure Alters Extracellular Placental miRNA Profile in Twin Pregnancies.

Prenatal exposure to endocrine-disrupting chemicals (EDCs) exerts both short- and long-term adverse effects on the developing fetus. However, the mechanisms underlying these effects have yet to be uncovered. Maternal-fetal signaling is mediated in part by signaling molecules (eg, microRNAs [miRNAs]) contained in extracellular vesicles (EVs) that are released by the placenta into the maternal circulation. We investigated whether maternal exposure to the EDCs phthalates and personal care products alters the miRNA profile of placental-derived EVs circulating in maternal blood. Blood and urine samples from pregnant women with uncomplicated term dichorionic, diamniotic twin pregnancies were analyzed as part of a larger study investigating correlations between exposure of phthalate and personal care products and epigenetic alterations in twin pregnancies. We explored correlations between maternal urinary levels of 13 phthalate and 12 personal care products metabolites and the miRNA profile of placental EVs (EV-miRNAs) circulating in maternal blood. The expression of miR-518e was highest among women with high urinary levels of monobenzyl phthalate and methyl paraben. miR-373-3p was the least expressed in women exposed to high levels of methyl paraben, and miR-543 was significantly downregulated in women exposed to high levels of paraben metabolites, dichlorophenol metabolites, and triclosan. In conclusion, this pilot study reveals that prenatal exposure to EDCs is associated with altered profile of circulating placenta-derived EV-miRNAs. Further studies are needed to generalize these results to singleton pregnancies and to assess whether these alterations are associated with pregnancy complications.

Urinary concentrations of phenols and phthalate metabolites reflect extracellular vesicle microRNA expression in follicular fluid.

BACKGROUND: Phenols and phthalates are potential endocrine disrupting chemicals (EDCs) that are associated with adverse health outcomes. These EDCs dysregulate a number of biomolecules and pathways, including microRNAs. MicroRNAs can be carried in transport systems called extracellular vesicles (EVs) that are present in most biofluids. EVs in the follicular fluid, which fills the ovarian follicle and influences oocyte developmental competency, carry microRNAs (EV-miRNAs) that have been associated with In Vitro Fertilization (IVF) outcomes. However, it remains unclear whether EDCs affect EV-miRNAs in follicular fluid. OBJECTIVES: This study sought to determine whether urinary concentrations of phenols and phthalates biomarkers are associated with EV-miRNAs expression in follicular fluid collected from women undergoing IVF treatment. METHODS: This cross-sectional study included 130 women recruited between January 2014 and August 2016 in a tertiary university-affiliated hospital. Participants provided urine samples during ovarian stimulation and on the day of oocyte retrieval. We assessed urinary concentrations of five phenols, eight phthalate metabolites, and one phthalate alternative metabolite. EV-miRNAs were isolated from follicular fluid and their expression profiles were measured using the TaqMan Open Array® Human microRNA panel. We fitted multivariable linear regression models and principal component analysis to examine associations between individual and molar sums of exposure biomarkers and EV-miRNAs. RESULTS: Of 754 miRNAs tested, we detected 133 EV-miRNAs in the microRNA array which expressed in at least 50% of the follicular fluid samples. After adjusting for multiple testing, we identified eight EV-miRNAs associated with individual phenols and phthalate metabolites, as well as molar ΣDEHP that met a q < 0.10 false-discovery rate (FDR) threshold. Hsa-miR-125b, hsa-miR-106b, hsa-miR-374a, and hsa-miR15b was associated with mono(2-ethylhexyl) phthalate concentrations, hsa-let-7c with concentrations mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), and the sum of metabolites of di(2-ethylhexyl) phthalate, hsa-miR-24 with mono-n-butyl phthalate concentrations, hsa-miR-19a with cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester (MHiNCH), and hsa-miR-375 with ethyl paraben concentrations. Using Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, gene targets and pathways of these EV-miRNAs were predicted in silico and 17 KEGG FDR-significant pathways related to follicular development and oocyte competence were identified. CONCLUSIONS: Our results show that urinary concentrations of select phenol and phthalate metabolites are correlated with altered EV-miRNAs expression in follicular fluid. These findings may provide insight regarding the molecular mechanisms underlying adverse effects of phenol and phthalate exposure on female fertility.

Extracellular microRNAs profile in human follicular fluid and IVF outcomes.

Encapsulated microRNAs (i.e., miRNAs within the extracellular vesicles, i.e., EV-miRNAs) have been detected in follicular fluid in both animal and human studies and different profiles have been associated with IVF cycle characteristics. However, limited studies to date have investigated other IVF outcomes, including fertilization status and embryo quality on day three". In this cohort, we performed a cross-sectional analysis on 126 women who contributed follicular fluid from a single follicle during a single IVF cycle. One hundred and ninety-two EV-miRNAs were assessed by univariable fold-change and multivariable logistic regression analyses. Hsa-miR-92a and hsa-miR-130b, were over-expressed in follicular fluid samples from oocytes that failed to fertilize compared to those that were normally fertilized. Additionally, hsa-miR-888 was over-expressed and hsa-miR-214 and hsa-miR-454 were under-expressed in samples that resulted in impaired day-3 embryo quality compared to top-quality day-3 embryos. After adjusting for confounders as BMI, smoking and total motile sperm, associations of these EV-miRNAs remained significant. In-silico KEGG pathway analyses assigned the identified EV-miRNAs to pathways of follicular growth and development, cellular signaling, oocyte meiosis, and ovarian function. Our findings suggest that EV-miRNAs may play a role in pathways of ovarian function and follicle development, which could be essential for understanding the molecular mechanisms that could lead to a successful pregnancy and birth.

Urinary concentrations of phthalate metabolites, bisphenols and personal care product chemical biomarkers in pregnant women in Israel.

Mounting evidence suggests possible adverse effects of intrauterine exposure to certain phenols and phthalates, two classes of endocrine disruptor chemicals, on the developing fetus, with consequences into later life. These findings have contributed to the replacement of some chemicals, such as di­2­ethylhexyl phthalate (DEHP) and bisphenol A (BPA), in consumer products. For the current study we quantified urinary concentrations of biomarkers of exposure among 50 pregnant women in Israel to several phthalates, bisphenols and personal care product chemicals, as well as DEHP and BPA alternatives. We detected 14 of the 31 biomarkers in more than 90% of the women. We detected biomarkers of 1,2­cyclohexane dicarboxylic acid, diisononyl ester (DINCH), bisphenol S, and bisphenol F not as frequently (27-56%). This study is the first to evaluate exposure to triclosan, bisphenols, parabens, and phthalates and BPA alternatives among Israeli pregnant women.

Placental lncRNA Expression Is Associated With Prenatal Phthalate Exposure.

Phthalates are endocrine-disrupting chemicals that can cross the placenta and affect the fetal epigenome. Among various epigenetic regulators of gene expression, long noncoding RNAs (lncRNAs) are important players that may also be involved in the manifestation of endocrine-disrupting chemical toxicity. We sought to explore the association between maternal urinary phthalate metabolite concentrations and lncRNA expression in human placenta to better understand potential mechanisms through which lncRNAs participate in mediating phthalate toxicity. Ten patients with uncomplicated dichorionic diamniotic twin pregnancies at term were included in this study. Urinary (n = 10) and placenta samples (n = 20) were collected for all participants. Urinary samples were analyzed for 15 phthalate metabolites and 2 phthalate alternative metabolites. Real-time PCR arrays were used to identify and quantify 87 lncRNAs from the placental samples. We tested the Spearman correlation matrix to compare prenatal phthalate measures against placental lncRNA levels. lncRNA levels showed large variations across samples, with no significant differences in lncRNA expression within twin pairs. Mono-(carboxynonyl) phthalate demonstrated consistently strong correlations with most lncRNAs. The strongest correlation was observed between mono-hydroxyisobutyl phthalate and LOC91450 (Rspearman = 0.88, p < .001). This correlation remained significant after Bonferroni adjustment. Other strong correlations were observed between mono-isobutyl phthalate, DPP10 and HOTTIP (Rspearman = -0.91, p < .001). AIRN, DACT3.AS1, DLX6, DPP10, HOTTIP, LOC143666, and LOC91450 were strongly correlated with the greatest number of phthalate metabolites. Further studies are needed to validate these results and understand if the altered expression of lncRNAs in human placenta has clinical significance.

Urinary concentrations of biomarkers of phthalates and phthalate alternatives and IVF outcomes.

Phthalates are a class of chemicals found in a large variety of consumer products. Available experimental and limited human data show adverse effects of some phthalates on ovarian function, which has raised concerns regarding potential effects on fertility. The aim of the current study was to determine whether urinary concentrations of metabolites of phthalates and phthalate alternatives are associated with intermediate and clinical in vitro fertilization (IVF) outcomes. We enrolled 136 women undergoing IVF in a Tertiary University Affiliated Hospital. Participants provided one to two urine samples per cycle during ovarian stimulation and before oocyte retrieval. IVF outcomes were abstracted from medical records. Concentrations of 17 phthalate metabolites and two metabolites of the phthalate alternative di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) were measured. Multivariable Poisson regression models with log link were used to analyze associations between tertiles of specific gravity adjusted phthalate or DINCH metabolites and number of total oocytes, mature oocytes, fertilized oocytes, and top quality embryos. Multivariable logistic regression models were applied to evaluate the association between tertiles of specific gravity adjusted phthalate or DINCH metabolites and probability of live birth. Urinary concentrations of the sum of di-2-ethylhexyl phthalate metabolites (∑DEHP) and the individual metabolites mono-2-ethyl-5-hydroxyhexyl phthalate, mono-2-ethyl-5-oxohexyl phthalate, and mono-2-ethyl-5-carboxypentyl phthalate were negatively associated with the number of total oocytes, mature oocytes, fertilized oocytes, and top quality embryos. Of the low molecular weight phthalates, higher monoethyl phthalate and mono-n-butyl phthalate concentrations were associated with significantly fewer total, mature, and fertilized oocytes. None of the urinary phthalate metabolite concentrations were associated with a reduced probability implantation, clinical pregnancy or live birth. Metabolites of DINCH were not associated with intermediate or clinical IVF outcomes. Our results suggest that DEHP may impair early IVF outcomes, specifically oocyte parameters. Additional research is needed to elucidate the potential effect of DEHP on female fertility in the general population.

Association between preconception maternal beverage intake and in vitro fertilization outcomes.

OBJECTIVE: To study whether maternal intake of beverage type affects IVF outcomes. DESIGN: A prospective study. SETTING: Tertiary, university-affiliated center. PATIENT(S): Three hundred forty women undergoing IVF from 2014 through 2016 for infertility as well as for pregenetic diagnosis for autosomal recessive diseases were enrolled during ovarian stimulation and completed a questionnaire describing their usual beverage consumption. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): IVF outcomes were abstracted from medical records. Total caffeine intake was estimated by summing the caffeine content for specific beverages multiplied by frequency of intake. Associations between specific types of beverages and IVF outcomes were analyzed using Poisson and logistic regression models adjusting for possible confounders. RESULT(S): Higher intake of sugared soda was associated with lower total, mature, and fertilized oocytes and top-quality embryos after ovarian stimulation. Women who consumed sugared soda had, on average, 1.1 fewer oocytes retrieved, 1.2 fewer mature oocytes retrieved, 0.6 fewer fertilized oocytes, and 0.6 fewer top-quality embryos compared with women who did not consume sugared soda. Furthermore, compared with women who did not drink sugared soda, the adjusted difference in percent of cycles resulting in live birth for women consuming 0.1-1 cups/day and >1 cup/day were -12% and -16%, respectively. No associations were found between consumption of coffee, caffeine, or diet sodas and IVF outcome. CONCLUSION(S): Sugared beverages, independent of their caffeine content, may be a bigger threat to reproductive success than caffeine and caffeinated beverages without added sugar.

In Vitro Exposure of Human Luteinized Mural Granulosa Cells to Dibutyl Phthalate Affects Global Gene Expression.

Exposure to dibutyl phthalate (DBP) is ubiquitous among women of reproductive age. Previous studies in animal models and in human cells in vitro have shown that exposure to DBP disrupts ovarian function. Here, we examined the effect of DBP on global gene expression in mural granulosa cells (MGCs) in vitro. Primary cultures of MGC obtained from 48 patients undergoing IVF were treated with increasing concentrations of DBP (0, 0.01, 0.1, 1, 10, or 100 µg/ml) for 48 h. Microarray analysis was used to identify genes exhibiting expression changes following DBP exposure. When compared with untreated cells, exposure to 100 µg/ml DBP resulted in significant differences in expression of 346 annotated genes (> 2-fold; q value < .05). Of them, 151 were upregulated and 195 downregulated. The main functional annotations affected by DBP were associated with cell cycle, mitosis, Rho GTPases, PLK1, Aurora B signaling pathways, and E2F-mediated regulation of DNA replication. No significant differences in gene expression were observed for the lower concentrations of DBP (0.01, 0.1, 1, and 10 µg/ml) compared with controls for both the microarray analysis and genes validated by quantitative real-time (qRT)-PCR. This study provides important molecular inputs on the effect of short-term DBP exposure on human MGCs in vitro. Our results indicate that acute treatment with high concentrations of DBP alters gene expression pathways mainly associated with the cell cycle.

Susceptibility of human cumulus cells to bisphenol a In vitro.

Bisphenol A (BPA) is detectable in follicular fluid. However, the effect of BPA exposure on human cumulus cells (CC) that surround the oocyte and are crucial for oocyte competence has been largely unexplored. We exposed primary cultures of CC to increasing concentrations of BPA [0,0.002, 0.02 and 20µg/mL] and tested the effects of BPA on the expression of genes associated with apoptosis using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR); we also assessed the effect of BPA on apoptosis by staining with anti-caspase 3. Exposure to 20µg/mL BPA led to significantly decreased expression of CDC20, BUB1B and HAS2 (p<0.03), increased expression of TRIB3 and LUM (p≤0.005), and increased frequency of cells positive for anti-CASP3 (p=0.03), compared to control. Our results imply that BPA may lead to ovarian toxicity by increasing CC apoptosis and provide an important molecular mechanism for the effect of BPA on human CC in vitro.

Dibutyl phthalate impairs steroidogenesis and a subset of LH-dependent genes in cultured human mural granulosa cell in vitro.

Exposure to di-butyl phthalate (DBP) exerts negative effects on female fertility in animal models, but human studies remain limited. Here, the effects of DBP exposure on mural granulosa cell function were investigated in primary cultures from women undergoing in vitro fertilization. Cultured cells treated with various doses of DBP (0, 0.01µg/mL, 0.1µg/mL, 1µg/mL, 10µg/mL, or 100µg/mL) for 48h were assessed using enzyme-linked immunosorbent assay and qRT-PCR. Treatment with 100µg/mL DBP resulted in significantly lower 17ß-estradiol and progesterone production (p<0.01). It also resulted in altered mRNA expression of steroidogenic, angiogenic, and epidermal growth factor-like growth factor genes: CYP11A1 (p<0.001), CYP19A1 (aromatase) (p<0.001), VEGF-A (p<0.02), BTC (p=0.009), and EREG (p=0.04). StAR expression was impaired after exposure to both 10 and 100µg/mL (p<0.03 and p<0.001, respectively). Our results indicate that in vitro exposure of granulosa cells to high doses of DBP alters cell functions.

Bisphenol-A exposure and gene expression in human luteinized membrana granulosa cells in vitro.

STUDY QUESTION: Does bisphenol-A (BPA) affect gene expression in human membrana granulosa cells (MGC)? SUMMARY ANSWER: In vitro, short exposure to supra-physiological concentrations of BPA alters human MGC gene expression. WHAT IS KNOWN ALREADY: Exposure to BPA may interfere with reproductive endocrine signaling. In vitro studies, mostly in animal models, have shown an inverse correlation between exposure to BPA and follicular growth, meiosis, and steroid hormone production in granulosa cells. STUDY DESIGN, SIZE, DURATION: Primary cultures of MGC obtained from 24 patients undergoing IVF (for PGD, male factor infertility or unexplained infertility) were exposed to various concentrations of BPA (0, 0.02, 0.2, 2 or 20 µg/ml) for 48 h. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study was conducted in a university-affiliated hospital. Microarray analysis was used to identify genes exhibiting expression changes following BPA exposure. Genes significantly altered were identified based on changes greater than 2-fold relative to the control group (not treated by BPA) and a Student's t-test P-value <0.05. Statistical significance was adjusted for multiple comparisons using the Benjamini-Hochberg method. Alterations in the expression of genes that are involved in the enriched functional annotations altered by BPA at the concentration of 20 µg/ml were confirmed by real-time PCR. MAIN RESULTS AND THE ROLE OF CHANCE: A distinct pattern of gene expression was observed in primary cultures of MGC exposed to the highest BPA concentration compared with untreated cells. We identified 652 genes that exhibited at least 2-fold differences in expression after BPA exposure (all P < 0.05 versus untreated). These genes were significantly enriched for annotations related to cell cycle progression, segregation of chromosomes, steroid metabolism, apoptosis, lipid synthesis, oocyte maturation and chromosomal alignment. No significant changes in gene expression were found at the lower doses of BPA most relevant to human exposure. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Human exposure to BPA in vivo occurs over long periods of time. In this in vitro model, cells were exposed to the chemical for 48 h only. Thus, the effects of BPA on the human follicle might be underestimated. WIDER IMPLICATIONS OF THE FINDINGS: As BPA exposure is ubiquitous, understanding the effects of the chemical on the ovary, specifically in women of reproductive age, has public health significance. The clinical evidence to date points to an association between BPA exposure and impaired IVF outcome, although not all studies have shown negative effects. Our study adds valuable mechanistic information showing that exposure to BPA alters granulosa cell gene expression at high and supra-physiological doses. STUDY FUNDING/COMPETING INTERESTS: This study was supported by grant number 1936/12 from the ISF. The authors have nothing to disclose.

Does BPA alter steroid hormone synthesis in human granulosa cells in vitro?

STUDY QUESTION: Does Bisphenol A (BPA) impair steroid hormone production in human luteinized granulosa cells in vitro? SUMMARY ANSWER: At supra-physiological concentrations, BPA alters progesterone and estradiol synthesis in vitro and significantly reduces the mRNA and protein expression levels of three genes encoding steroidogenesis enzymes. WHAT IS KNOWN ALREADY: In IVF patients, the effects of BPA exposure on cycle outcome are controversial. Previous animal studies have shown that granulosa cell steroid hormone synthesis is compromised after BPA exposure, but their findings have been difficult to replicate in humans due, in part, to the low availability of discarded biological material. STUDY DESIGN, SIZE, DURATION: Luteinized granulosa cells obtained from 44 fertile and infertile patients undergoing in vitro fertilization were cultured for 48 h with different concentrations of BPA (0, 0.2, 0.02, 2.0, 20 µg/ml). PARTICIPANTS/MATERIALS, SETTING, METHODS: Culture medium and total RNA extracted from the luteinized granulosa cells were examined for estradiol and progesterone levels as well as mRNA and protein expression of steroidogenesis enzymes, using enzyme immunoassays, real-time PCR and western blots. MAIN RESULTS AND THE ROLE OF CHANCE: Treatment of granulosa cells with 2 or 20 µg/ml BPA for 48 h resulted in significantly lower progesterone biosynthesis (P < 0.005 and <0.001, respectively). Estradiol production was significantly altered only after incubation with 20 µg/ml of BPA (P < 0.001). These concentrations also significantly reduced the mRNA levels of 3ß-hydroxysteroid dehydrogenase (3ß-HSD), CYP11A1 and CYP19A1 without affecting StAR and 17ß-hydroxysteroid dehydrogenase mRNA expression. Similarly, 3ß-HSD, CYP11A1 and CYP19A1 protein levels were reduced after administration of 20 µg/ml BPA. Lower BPA concentrations similar to, and up to 100 times, the concentrations measured in human follicular fluid, serum and urine did not alter steroidogenesis in primary granulosa cell cultures. LIMITATIONS, REASONS FOR CAUTION: This was an in vitro study investigating the effects of acute exposure (48 h) of BPA on discarded material. As such, the model may not accurately reflect the effect of BPA on the physiological events of follicular steroid hormone synthesis in vivo. WIDER IMPLICATIONS OF THE FINDINGS: Our results show that in vitro exposure to BPA at low doses does not affect granulosa cells steroidogenesis. Combined with recent in vivo studies, these data can be reassuring but further studies are needed to assess the effects of chronic exposure to BPA on ovarian steroidogenesis. STUDY FUNDING AND COMPETING INTERESTS: This study was supported by grant number 1936/12 from the Israeli Science Foundation (ISF). The authors have no conflict of interest.