HMGB1 regulates autophagy of placental trophoblast through ERK signaling pathway

OBJECTIVE

The purpose of this study is to investigate the role of high mobility group protein B1 (HMGB1) in placental development and fetal growth.

METHODS

We employed the Cre-loxP recombination system to establish a placenta-specific HMGB1 knockout mouse model. Breeding HMGB1flox/flox mice with Elf5-Cre mice facilitated the knockout, leveraging Elf5 expression in extra-embryonic ectoderm, ectoplacental cone, and trophoblast giant cells at 12.5 days of embryonic development. The primary goal of this model was to elucidate the molecular mechanism of HMGB1 in placental development, assessing parameters such as placental weight, fetal weight, and bone development. Additionally, we utilized lentiviral interference and overexpression of HMGB1 in human trophoblast cells to further investigate HMGB1's functional role.

RESULTS

Our findings indicate that HMGB1flox/floxElf5cre/+ mouse display fetal growth restriction (FGR), characterized by decreased placental and fetal weight and impaired bone development. And the absence of HMGB1 inhibits autophagosome formation, impairs lysosomal degradation, and disrupts autophagic flux. Depletion of HMGB1 in human trophoblast cells also suppresses cell viability, proliferation, migration, and invasion by inhibiting the ERK signaling pathway. Overexpression of HMGB1 observed the opposite phenotypes.

CONCLUSIONS

HMGB1 participates in the regulation of autophagy through the ERK signaling pathway and affects placental development.

The association of post-embryo transfer SARS-CoV-2 infection with early pregnancy outcomes in in vitro fertilization: a prospective cohort study

BACKGROUND

The influence of SARS-CoV-2 infection after embryo transfer on early pregnancy outcomes in in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment remains inadequately understood. This knowledge gap endures despite an abundance of studies investigating the repercussions of preceding SARS-CoV-2 infection on early pregnancy outcomes in spontaneous pregnancies.

OBJECTIVE

This study aimed to investigate the association between SARS-CoV-2 infection within 10 weeks after embryo transfer and early pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment.

STUDY DESIGN

This prospective cohort study was conducted at a single public in vitro fertilization center in China. Female patients aged 20 to 39 years, with a body mass index ranging from 18 to 30 kg/m2, undergoing in vitro fertilization/intracytoplasmic sperm injection treatment, were enrolled between September 2022 and December 2022, with follow-up extended until March 2023. The study tracked SARS-CoV-2 infection time (≤14 days, ≤28 days, and ≤10 weeks after embryo transfer), symptoms, vaccination status, the interval between vaccination and embryo transfer, and early pregnancy outcomes, encompassing biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate. The study used single-factor analysis and multivariate logistic regression to examine the association between SARS-CoV-2 infection status, along with other relevant factors, and the early pregnancy outcomes.

RESULTS

A total of 857 female patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were analyzed. In the first stage, SARS-CoV-2 infection within 14 days after embryo transfer did not have a significant negative association with the biochemical pregnancy rate (adjusted odds ratio, 0.74; 95% confidence interval, 0.51-1.09). In the second stage, SARS-CoV-2 infection within 28 days after embryo transfer had no significant association with the implantation rate (36.6% in infected vs 44.0% in uninfected group; P=.181). No statistically significant association was found with the clinical pregnancy rate after adjusting for confounding factors (adjusted odds ratio, 0.69; 95% confidence interval, 0.56-1.09). In the third stage, SARS-CoV-2 infection within 10 weeks after embryo transfer had no significant association with the early miscarriage rate (adjusted odds ratio, 0.77; 95% confidence interval, 0.35-1.71).

CONCLUSION

Our study suggests that SARS-CoV-2 infection within 10 weeks after embryo transfer may not be negatively associated with the biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. It is important to note that these findings are specific to the target population of in vitro fertilization/intracytoplasmic sperm injection patients aged 20 to 39 years, without previous SARS-CoV-2 infection, and with a body mass index of 18 to 30 kg/m2. This information offers valuable insights, addressing current concerns and providing a clearer understanding of the actual risk associated with SARS-CoV-2 infection after embryo transfer.

Study on the optimal time limit of frozen embryo transfer and the effect of a long-term frozen embryo on pregnancy outcome

In this retrospective study conducted at Sichuan Jinxin Xinan Women and Children's Hospital spanning January 2015 to December 2021, our objective was to investigate the impact of embryo cryopreservation duration on outcomes in frozen embryo transfer. Participants, totaling 47,006 cycles, were classified into 3 groups based on cryopreservation duration: ≤1 year (Group 1), 1 to 6 years (Group 2), and ≥6 years (Group 3). Employing various statistical analyses, including 1-way ANOVA, Kruskal-Wallis test, chi-square test, and a generalized estimating equation model, we rigorously adjusted for confounding factors. Primary outcomes encompassed clinical pregnancy rate and Live Birth Rate (LBR), while secondary outcomes included biochemical pregnancy rate, multiple pregnancy rate, ectopic pregnancy rate, early and late miscarriage rates, preterm birth rate, neonatal birth weight, weeks at birth, and newborn sex. Patient distribution across cryopreservation duration groups was as follows: Group 1 (40,461 cycles), Group 2 (6337 cycles), and Group 3 (208 cycles). Postcontrolling for confounding factors, Group 1 exhibited a decreased likelihood of achieving biochemical pregnancy rate, clinical pregnancy rate, and LBR (OR < 1, aOR < 1, P < .05). Furthermore, an elevated incidence of ectopic pregnancy was observed (OR > 1, aOR > 1), notably significant after 6 years of freezing time [aOR = 4.141, 95% confidence intervals (1.013-16.921), P = .05]. Cryopreservation exceeding 1 year was associated with an increased risk of early miscarriage and preterm birth (OR > 1, aOR > 1). No statistically significant differences were observed in birth weight or sex between groups. However, male infant birth rates were consistently higher than those of female infants across all groups. In conclusion, favorable pregnancy outcomes align with embryo cryopreservation durations within 1 year, while freezing for more than 1 year may diminish clinical pregnancy and LBRs, concurrently elevating the risk of ectopic pregnancy and preterm birth.

Emodin improves glucose metabolism and ovarian function in PCOS mice via the HMGB1/TLR4/NF-κB molecular pathway

In brief

Obese PCOS mice display metabolic and endocrine disorders that manifest as abnormal metabolism of glucose and dysfunctions in the reproductive system. This study demonstrates that emodin alleviates most of these conditions possibly via the HMGB1/TLR4/NF-kB pathway.

Abstract

PCOS is a reproductive disorder with an unclear etiology. It affects 5-10% of women worldwide and is largely associated with impaired glucose metabolism and obesity. HMGB1 is a nuclear protein associated with impaired glucose metabolism and PCOS. We sought to investigate the potential therapeutic effects of emodin on glucose metabolism and ovarian functions in PCOS mice via the HMGB1 molecular pathway. A high-fat diet (HFD) and dehydroepiandrosterone (DHEA)- induced PCOS mouse model comprising four experimental groups was established: control, PCOS, PCOS plus emodin, and PCOS plus vehicle groups. Emodin administration attenuated obesity, elevated fasting glucose levels, impaired glucose tolerance, and insulin resistance, and improved the polycystic ovarian morphology of PCOS mice. Additionally, it lowered elevated serum HMGB1, LH, and testosterone levels in PCOS mice. Elevated ovarian protein and mRNA levels of HMGB1 and TLR4 in PCOS mice were also lowered following emodin treatment. Furthermore, emodin lowered high NF-ĸB/65 protein levels in the ovaries of PCOS mice. Immunohistochemical staining of the ovaries revealed strong HMGB1, TLR4, and AR expressions in PCOS mice, which were lowered by emodin treatment. Moreover, emodin significantly increased GLUT4, IRS2, and INSR levels that were lowered by PCOS. Overall, our study showed that emodin alleviated the impaired glucose metabolism and improved ovarian function in PCOS mice, possibly via the HMGB1/TLR4/NF-ĸB signaling pathway. Thus, emodin could be considered a potential therapeutic agent in the management of PCOS.

miR-181d-5p, which is upregulated in fetal growth restriction placentas, inhibits trophoblast fusion via CREBRF

PURPOSE

Fetal growth restriction (FGR) is a common complication characterized by impaired placental function and unfavorable pregnancy outcomes. This study aims to elucidate the expression pattern of miR-181d-5p in FGR placentas and explore its effects on trophoblast fusion.

METHODS

The expression pattern of miR-181d-5p in human FGR placentas were evaluated using qRT-PCR. Western blot, qRT-PCR, and Immunofluorescence analysis were performed in a Forskolin (FSK)-induced BeWo cell fusion model following the transfection of miR-181d-5p mimic or inhibitor. Potential target genes for miR-181d-5p were identified by screening miRNA databases. The interaction between miR-181d-5p and Luman/CREB3 Recruitment Factor (CREBRF) was determined through a luciferase assay. Moreover, the effect of CREBRF on BeWo cell fusion was examined under hypoxic conditions.

RESULTS

Aberrant up-regulation of miR-181d-5p and altered expression of trophoblast fusion makers, including glial cell missing 1 (GCM1), Syncytin1 (Syn1), and E-cadherin (ECAD), were found in human FGR placentas. A down-regulation of miR-181d-5p expression was observed in the FSK-induced BeWo cell fusion model. Transfection of the miR-181d-5p mimic resulted in the inhibition of BeWo cell fusion, characterized by a down-regulation of GCM1 and Syn1, accompanied by an up-regulation of ECAD. Conversely, the miR-181d-5p inhibitor promoted BeWo cell fusion. Furthermore, miR-181d-5p exhibited negative regulation of CREBRF, which was significantly down-regulated in the hypoxia-induced BeWo cell model. The overexpression of CREBRF was effectively ameliorated the impaired BeWo cell fusion induced by hypoxia.

CONCLUSIONS

Our study demonstrated that miR-181d-5p, which is elevated in FGR placenta, inhibited the BeWo cell fusion through negatively regulating the expression of CREBRF.

Young obese patients may benefit from GnRH-a long protocol contributing to higher implantation rate and live birth rate of fresh IVF-ET cycles

Introduction

Obesity has detrimental influences on women reproductive health. There is little experience in optimizing controlled ovarian hyperstimulation (COH) protocols to treat Chinese obese patients who are undergoing in vitro fertilization and embryo transfer (IVF-ET) therapy.

Methods

The clinical outcome differences were retrospectively analyzed among obese patients who received gonadotrophin-releasing hormone agonist (GnRH-a), GnRH antagonist (GnRH-ant), micro dose GnRH-a (mGnRH-a) and GnRH-a long protocol in IVF-ET cycle at Chengdu Jinjiang Hospital for Women's and Children's Health from January 2014 to December 2019.

Results

The transplantation rate of the GnRH-a long protocol group (59.1%) was higher than that of the GnRH-ant (25.9%) and mGnRH-a (36.7%) groups. The total live birth rate of the GnRH-a long protocol group (46.2%) was higher than that of the GnRH-a group (25.9%) and GnRH-ant group (40.3%). The total number of frozen embryos in the GnRH-ant group was higher than in the other groups (P < 0.05). After adjusting for confounding factors, the logistic regression analysis showed that the GnRH-a long protocol group had higher probabilities of biochemical pregnancy, clinical pregnancy, and live birth than the GnRH-a protocol group. The Gn dose in the mGnRH-a group was higher than the other three groups. Whether single or twin, there were similar neonatal outcomes among the four groups including premature birth rate, Apgar score, newborn weight, and length.

Conclusion

For young obese patients undergoing IVF-ET, the GnRH-a long protocol for COH gives better pregnancy outcomes.

Glycyrrhizin ameliorates impaired glucose metabolism and ovarian dysfunction in a polycystic ovary syndrome mouse model

The aim of this study was to determine the impact of glycyrrhizin, an inhibitor of high mobility group box 1, on glucose metabolic disorders and ovarian dysfunction in mice with polycystic ovary syndrome. We generated a polycystic ovary syndrome mouse model by using dehydroepiandrosterone plus high-fat diet. Glycyrrhizin (100 mg/kg) was intraperitoneally injected into the polycystic ovary syndrome mice and the effects on body weight, glucose tolerance, insulin sensitivity, estrous cycle, hormone profiles, ovarian pathology, glucolipid metabolism, and some molecular mechanisms were investigated. Increased number of cystic follicles, hormonal disorders, impaired glucose tolerance, and decreased insulin sensitivity in the polycystic ovary syndrome mice were reverted by glycyrrhizin. The increased high mobility group box 1 levels in the serum and ovarian tissues of the polycystic ovary syndrome mice were also reduced by glycyrrhizin. Furthermore, increased expressions of toll-like receptor 9, myeloid differentiation factor 88, and nuclear factor kappa B as well as reduced expressions of insulin receptor, phosphorylated protein kinase B, and glucose transporter type 4 were restored by glycyrrhizin in the polycystic ovary syndrome mice. Glycyrrhizin could suppress the polycystic ovary syndrome-induced upregulation of high mobility group box 1, several inflammatory marker genes, and the toll-like receptor 9/myeloid differentiation factor 88/nuclear factor kappa B pathways, while inhibiting the insulin receptor/phosphorylated protein kinase B/glucose transporter type 4 pathways. Hence, glycyrrhizin is a promising therapeutic agent against polycystic ovary syndrome.

Maternal Hepatitis B Virus Infection and Pregnancy Outcomes of Freeze-Thaw Embryo Transfer

This cohort study assesses the association of maternal hepatitis B virus (HBV) serostatus with pregnancy outcomes in women undergoing freeze-thaw embryo transfer (FET).

Silicon dioxide nanoparticles compromise decidualization via autophagy impairment to possibly cause embryo resorption

The wide application of silicon dioxide nanoparticles (SiO₂NPs) has raised concerns about their harmful effects on reproduction. The purpose of this research was to investigate the toxic effects and the possible mechanisms by which SiO₂NPs affect decidualization and pregnancy progression. We found that SiO₂NPs could inhibit decidualization, both in mice and in human endometrial stromal cells (HESCs). Embryo resorption was also evident in mice treated with SiO₂NPs. When HESCs were treated with SiO₂NPs, decidualization was inhibited and there was an increase in intracellular lysosomes and autophagosomes as well as the blockage of autophagic flux. Interestingly, a reduction of autophagosome accumulation via 3-methyladenine (3MA) significantly restored the decidualization of HESCs. In summary, our results indicate that SiO₂NPs can affect embryo survival by impairing decidualization through a dysfunctional autophagic process.

Effects of sequential cleavage and blastocyst embryo transfer on pregnancy outcomes in patients with poor ovarian response

The management of patients with poor ovarian response (POR) remains a major challenge for fertility specialists in in vitro fertilization-embryo transfer (IVF-ET). In this retrospective cohort study, we aimed to evaluate the clinical effect of sequential transfer on pregnancy outcomes in patients with POR. A total of 3579 POR patients who underwent the first frozen embryo transfer (FET) cycle were enrolled from January 2018 to April 2021. The patients were divided into three groups according to the embryo transfer (ET) strategy adopted: a study group that included POR patients in whom a cleavage-stage embryo (day 3) and a blastocyst (day 5/6) were transferred (sequential transfer group), and two control groups in whom two cleavage-stage embryos (D3-dET group) or two blastocysts (D5/6-dET group) were transferred. The study group was matched with the control groups at a ratio of 1:4 by propensity score matching (PSM). The main pregnancy outcomes measured were the live birth rate and multiple pregnancy rate. After PSM, the live birth rate in the sequential transfer group was significantly higher than that in the D3-dET group (44.2% vs. 34.3%, P = 0.019), and was similar to that in the D5/6-dET group (44.2% vs. 45.3%; P = 0.90). In addition, there was no increase in the risk of multiple pregnancy among POR patients undergoing sequential transfer compared with both D3-dET (26.7% vs. 25.6%, P = 0.85) and D5/6-dET (26.7% vs. 28.4%, P = 0.97) groups. These findings imply that sequential transfer is an effective option for POR patients and could be utilized after careful consideration.

Effect of interval between oocyte retrieval and resuscitation embryo transfer on pregnancy outcomes

Objectives

Resuscitation transfer of embryos after elective cryopreservation has been widely applied in in vitro fertilization-embryo transfer (IVF-ET) therapy for human infertility or sterility owing to higher embryo implantation rates. This method separates oocyte retrieval from embryo transfer. The optimal time for frozen embryo transfer (FET) remains unknown. Therefore, this study mainly compares the advantages and disadvantages of delayed FET and immediate FET through retrospective analysis.

Methods

We analyzed real world data of patients who underwent resuscitation transplantation between October 2019 and July 2021 at the Reproductive Center of Chengdu Jinjiang Hospital for Women's and Children's Health. Propensity score matching was applied to control potential confounding factors. A total of 5,549 patients who received at least one FET were analyzed. Patients undergoing transplantation within 60 days of oocyte retrieval were included in the immediate FET group (n = 1,265) and those undergoing transplantation > 60 days after retrieval were included in the delayed FET group (n = 4,284).

Results

Live birth rates between the two groups were comparable (45.25% vs. 45.76%, p = 0.757). Moreover, no difference was observed in the rates of biochemical pregnancy (64.50% vs. 66.80%), clinical pregnancy (55.24% vs. 56.83%), ectopic pregnancy (1.47% vs. 1.39%), early miscarriage (14.41% vs. 16.20%), late miscarriage (2.21% vs. 2.09%), singleton premature delivery (16.67% vs. 18.29%), and neonatal deformity (1.97% vs. 1.80%). After stratifying the patients based on the type of embryo transferred, number of embryos transferred, FET protocol, and good prognosis criteria, live birth rates remained comparable between the two groups (p > 0.05).

Conclusion

Pregnancy outcomes were comparable between the immediate and delayed FET groups.

Corrigendum: Effects of Yulin Tong Bu formula on modulating gut microbiota and fecal metabolite interactions in mice with polycystic ovary syndrome

[This corrects the article DOI: 10.3389/fendo.2023.1122709.].

Effects of Yulin Tong Bu formula on modulating gut microbiota and fecal metabolite interactions in mice with polycystic ovary syndrome

BACKGROUND

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenism, ovarian dysfunction and polycystic ovarian morphology. Gut microbiota dysbiosis and metabolite are associated with PCOS clinical parameters. Yulin Tong Bu formula (YLTB), a traditional Chinese medicine formula, has been recently indicated to be capable of ameliorating polycystic ovary symptoms and correcting abnormal glucose metabolism. However, the therapeutic mechanism of YLTB on PCOS has not been fully elucidated.

METHODS

A pseudo sterile mouse model was established during this four-day acclimatization phase by giving the animals an antibiotic cocktail to remove the gut microbiota. Here, the therapeutic effects of YLTB on PCOS were investigated using dehydroepiandrosterone plus high-fat diet-induced PCOS mice model. Female prepuberal mice were randomly divided into three groups; namely, the control group, PCOS group and YLTB (38.68 g·kg^-1·day^-1) group. To test whether this effect is associated with the gut microbiota, we performed 16S rRNA sequencing studies to analyze the fecal microbiota of mice. The relationships among metabolites, gut microbiota, and PCOS phenotypes were further explored by using Spearman correlation analysis. Then, the effect of metabolite ferulic acid was then validated in PCOS mice.

RESULTS

Our results showed that YLTB treatment ameliorated PCOS features (ovarian dysfunction, delayed glucose clearance, decreased insulin sensitivity, deregulation of glucolipid metabolism and hormones, etc.) and significantly attenuated PCOS gut microbiota dysbiosis. Spearman correlation analysis showed that metabolites such as ferulic acid and folic acid are negatively correlated with PCOS clinical parameters. The effect of ferulic acid was similar to that of YLTB. In addition, the bacterial species such as Bacteroides dorei and Bacteroides fragilis were found to be positively related to PCOS clinical parameters, using the association study analysis.

CONCLUSION

These results suggest that YLTB treatment systematically regulates the interaction between the gut microbiota and the associated metabolites to ameliorate PCOS, providing a solid theoretical basis for further validation of YLTB effect on human PCOS trials.

Low LH level does not indicate poor IVF cycle outcomes with GnRh-a single trigger: a retrospective analysis

OBJECTIVE

To compare the in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycle outcomes between patients with low and normal serum luteinizing hormone (LH) levels on the day after a gonadotropin-releasing hormone agonist (GnRH-a) single trigger. We further investigated the efficacy of human chorionic gonadotropin (hCG) retrigger on IVF cycle outcomes in patients with low LH levels after GnRH-a single trigger.

METHODS

We retrospectively analyzed 957 infertile patients (tubal factor, ovulation disorders, male sperm factor, or unexplained infertility) who were treated with IVF/ICSI at the Chengdu Xinan Gynecology Hospital from July 2017 to December 2020. Patients received sufficient GnRH-a single trigger were divided into two groups based on the serum LH levels on the next day of trigger: normal serum LH levels (≥ 10 mIU/mL) group (control group, n = 906) and low LH levels (< 10 mIU/mL) group (experimental group, n = 51). And the efficacy of hCG retrigger on IVF/ICSI cycle outcomes in 10 patients with low LH levels after GnRH-a single trigger.

RESULTS

There were no significant differences in IVF/ICSI cycle outcomes, including egg yield, two pronuclei fertilization rate, excellent embryo rate, or live birth rate of frozen-thawed embryos between patients with low and normal LH levels after GnRH-a trigger. It showed significantly higher risk of ovarian hyperstimulation syndrome in the group of low LH levels [ 0.7%(1/137) vs. 8.5%(4/47), P = 0.016] compared with the group of normal LH levels who received GnRH-a single trigger. The hCG retrigger had no obvious efficacy on cycle outcomes in patients with low LH levels, including oocytes retrieved, fertilization rate, embryo conditions, and live birth rate of frozen-thawed cycles.

CONCLUSION

The IVF/ICSI cycle outcomes of patients with low LH levels on the day after GnRH-a administration were similar to those of patients with normal LH levels. Blood LH test might not be required on the day following the trigger. The hCG retrigger did not have any effect on the cycle outcomes, suggesting that immediate retriggering with hCG was unnecessary.

Effect of artificial cycle with or without GnRH-a pretreatment on pregnancy and neonatal outcomes in women with PCOS after frozen embryo transfer: a propensity score matching study

BACKGROUND

In frozen embryo transfer (FET), there is limited consensus on the best means of endometrial preparation in terms of the reproductive outcomes in women with polycystic ovary syndrome (PCOS). The present study aimed to compare the pregnancy and neonatal outcomes following artificial cycle FET (AC-FET) with or without gonadotropin-releasing hormone agonist (GnRH-a) pretreatment among women with PCOS.

METHODS

A total of 4503 FET cycles that satisfied the inclusion criteria were enrolled in this retrospective cohort study between 2015 and 2020. The GnRH-a group received GnRH-a pretreatment while the AC-FET group did not. Propensity score matching (PSM) method and multivariate logistic regression analysis were performed to adjust for potential confounding factors.

RESULTS

After PSM, women in the GnRH-a group suffered a significantly lower miscarriage rate (11.2% vs. 17.1%, P = 0.033) and a higher live birth rate (LBR) compared with those in the AC-FET group (63.1% vs. 56.8%, P = 0.043). No differences were observed in the rates of biochemical pregnancy, clinical pregnancy and ectopic pregnancy between the two groups. A higher mean gestational age at birth was observed in the GnRH-a group than in the AC-FET group (39.80 ± 2.01 vs. 38.17 ± 2.13, P = 0.009). The incidence of neonatal preterm birth (PTB) in the GnRH-a group was lower than that in the AC-FET group (7.4% vs. 14.9%, P = 0.009). Singleton newborns conceived after GnRH-a group were more likely to be small for gestational age (SGA) than those born after AC-FET group (16.4% vs. 6.8%, P = 0.009). However, no significant differences were found between the two groups in terms of mean birthweight, apgar score, the rates of macrosomia, large for gestational age and low birth weight.

CONCLUSION(S)

In women with PCOS who underwent AC-FET, GnRH-a pretreatment was significantly associated with a higher live birth rate and a reduced risk of neonatal PTB. However, there was a concomitant increase in the risk of developing SGA babies.

Associations of early-life factors and indoor environmental exposure with asthma among children: a case-control study in Chongqing, China

BACKGROUND

Childhood asthma has substantial effects on children's health. It is important to identify influencing factors in early life in the development of childhood asthma. We aim to evaluate the effects of early-life factors and indoor environmental exposure on childhood asthma in Chongqing, China.

METHOD

We designed a case-control study to enrol children with asthma aged 3 to < 14 years old and controls in Chongqing, China. The "Children's Early Life and Indoor Environment Survey" was used to collect the early-life factors and indoor environmental exposure of foetuses in utero and of infants during the first 3 years of life. A multivariate logistic regression model was used to evaluate the association between independent variables and childhood asthma and the interaction of early-life factors and environmental exposure.

RESULTS

A total of 160 asthma cases and 247 controls were included in this study. The mean ages of the cases and controls were 5.53 ± 1.88 and 5.72 ± 2.34 years, respectively (P = 0.192). Early-life factors and indoor environmental exposure were independently associated with childhood asthma. Infectious diseases of the respiratory system in children under 3 years old [adjusted odds ratio (OR) = 5.76, 95% confidence interval (CI) 2.49-13.30], bedroom air conditioner use (adjusted OR = 4.61, 95% CI 1.45-14.64), and bedroom dampness/mould (adjusted OR = 2.98, 95% CI 1.54-5.75) ranked as the three most significant exposures associated with the risk of childhood asthma. Other factors associated with an increased risk of childhood asthma included second-hand smoke exposure in early life (adjusted OR = 1.93, 95% CI 1.24-3.00), neonatal pneumonia (adjusted OR = 1.90, 95% CI 1.05-3.42) and maternal allergic diseases during pregnancy (adjusted OR = 2.13, 95% CI 1.10-4.10). The interaction effects of child second-hand smoke exposure with other covariates were not found to be statistically significant.

CONCLUSIONS

Early-life factors and indoor environmental exposure are closely related to childhood asthma in Chongqing, China. Further interventions and management in the early life of children should be considered to prevent and control childhood asthma in Chongqing and similar cities.

A decrease in CD2 expression on NK cells is associated with PCOS but not influenced by metformin in a mouse model

Problem: Natural killer (NK) cells from the peripheral blood and spleen represent the source from which various tissues replenish their immune cell populations. Hyperandrogenism and high interleukin-2 (IL-2) levels are factors present in polycystic ovary syndrome (PCOS). These factors and metformin, one of the commonest medications used in treating PCOS, may have an impact on NK cell levels and its receptor profile. However, this is presently unknown. Here, we aimed to assess the levels of peripheral blood and splenic NK cells and their CD2 and CD94 expression patterns in a PCOS mouse model and test whether metformin could reverse these effects.

Method of study: Four mouse groups were designed as follows (n = 15/group): control, PCOS, PCOS plus vehicle, PCOS plus metformin. Dehydroepiandrosterone (DHEA) and a high-fat diet (HFD) were administered to induce the PCOS mouse model. Flow cytometry was used to analyze the expression of CD2 and CD94 on peripheral blood and splenic NK cells. Serum IL-2 levels were analyzed through enzyme-linked immunosorbent assays.

Results: PCOS mice had a decreased mean fluorescence intensity (MFI) of CD2 on peripheral blood NK cells and a decreased percentage of CD2+ splenic NK cells. Metformin administration did not significantly influence these changes; however, it reduced the splenic NK cell count. IL-2 levels were significantly elevated in PCOS mice and significantly reduced after metformin administration.

Conclusions: Our findings proved the association of PCOS with an altered expression of CD2 on peripheral blood and splenic NK cells and that of metformin with a lowered splenic NK cell reserve in PCOS conditions. These findings could further unlock key mechanisms in PCOS pathophysiology and in the mechanism of action of metformin, towards improving PCOS management.

An Individualized Recommendation for Controlled Ovary Stimulation Protocol in Women Who Received the GnRH Agonist Long-Acting Protocol or the GnRH Antagonist Protocol: A Retrospective Cohort Study

BACKGROUND

The GnRH agonist long-acting protocol and GnRH antagonist protocol are widely used in ovarian stimulation. Which protocol eliciting higher live birth rate for IVF/ICSI patients with different ages, different ovarian reserves and different body mass index (BMI) has not been studied. However, among these protocols, the one that elicits higher live birth in IVF/ICSI patients with different ages, ovarian reserves and body mass indexes (BMI) has not been identified.

METHODS

This was a retrospective cohort study about 8579 women who underwent the first IVF-ET from January, 2018 to August, 2021. Propensity Score Matching (PSM) was used to improve the comparability between two protocols.

RESULTS

After PSM, significant higher live birth rates were found in the GnRH agonist long-acting protocol compared to GnRH antagonist protocol (44.04% vs. 38.32%) (p<0.001). Stratified analysis showed that for those with AMH levels between 3 ng/ml and 6 ng/ml, with BMI ≥ 24 kg/m² and were aged ≥ 30 years old, and for those women with BMI < 24kg/m² and were aged ≥30 years whose AMH levels were ≤ 3ng/ml, the GnRH agonist long-acting protocol was more likely to elicit live births [OR (95%CI), 2.13(1.19,3.80)], [OR (95%CI), 1.41(1.05,1.91)]. However, among women with BMI ≥ 24kg/m² and were aged ≥30 years whose AMH levels were ≤ 3ng/ml, the GnRH agonist long-acting protocol had a lower possibility of eliciting live births [OR (95%CI), 0.54(0.32,0.90)]. Also, among women with AMH levels between 3 ng/ml and 6 ng/ml, with BMI ≥ 24 kg/m² and with age < 30 years and for those with AMH levels between 3 ng/ml and 6 ng/ml, regardless of age, and with BMI<24kg/m2,, the possibility of live births was similar between the two protocols [OR (95%CI), 1.06(0.60,1.89)], [OR (95%CI), 1.38(0.97,1.97)], [OR (95%CI), 0.99(0.72,1.37)]. Among the women with AMH levels ≤ 3 ng/ml and with were aged < 30years, regardless of BMI, the possibility of live birth was similar between the two protocols [OR (95%CI), 1.02(0.68,1.54)], [OR (95%CI), 1.43(0.68,2.98)]. Moreover, among women with AMH levels ≥ 6ng/ml, the possibility of live birth was similar between the two protocols [OR (95%CI),1.42(0.75,2.69)], [OR (95%CI),1.02(0.19,5.35)], [OR (95%CI), 1.68(0.81,3.51)], [OR (95%CI), 0.51(0.10,2.55)].

CONCLUSIONS

The suitability of the GnRH agonist long-acting protocol or GnRH antagonist protocol to infertility patients is dependent on specific biological characteristics of the patients.

The role of fascin in carcinogenesis and embryo implantation

The cytoskeleton, with its actin bundling proteins, plays crucial roles in a host of cellular function, such as cancer metastasis, antigen presentation and trophoblast migration and invasion, as a result of cytoskeletal remodeling. A key player in cytoskeletal remodeling is fascin. Upregulation of fascin induces the transition of epithelial phenotypes to mesenchymal phenotypes through complex interaction with transcription factors. Fascin expression also regulates mitochondrial F-actin to promote oxidative phosphorylation (OXPHOS) in some cancer cells. Trophoblast cells, on the other hand, exhibit similar physiological functions, involving the upregulation of genes crucial for its migration and invasion. Owing to the similar tumor-like characteristics among cancer and trophoblats, we review recent studies on fascin in relation to cancer and trophoblast cell biology; and based on existing evidence, link fascin to the establishment of the maternal-fetal interface.

Iodothyronine deiodinase 2 (DiO2) regulates trophoblast cell line cycle, invasion and apoptosis; and its downregulation is associated with early recurrent miscarriage

INTRODUCTION

Trophoblast development is a crucial event in placentation and pregnancy complications but its underlying mechanisms remain unclear. Thus, we aimed at investigating the role of DiO2 in trophoblast cell line decisions and assessing its placental villous expression in early recurrent miscarriage (ERM) patients.

METHODS

The placental villous expression of DiO2 was determined with immunofluorescence. Cell proliferation was measured with the CCK8 kit while cell-cycle and apoptosis were studied with flow-cytometry. Cell migration and invasion were measured with wound-healing and transwell assays, respectively. Gene expression was then assessed with RT-qPCR and western blotting.

RESULTS

DiO2 is expressed in the CTB, PCT, DCT and STB of the placenta. Its overexpression arrested trophoblast cell line proliferation at the G1 phase of the cell-cycle by downregulating cyclin-D1 and PCNA, while promoting apoptosis via increased caspase-3 activity and inhibition of the AKT and ERK1/2 signaling pathways. Also, it augmented trophoblast cell line migration and invasion via the upregulation of N-cadherin, vimentin, fascin-1, twist-1 and other epithelial-mesenchymal transition genes. DiO2 knockdown elicited the opposite effects. Surprisingly, each of these effects of DiO2 manipulation was not mediated by thyroid hormone metabolism. Assessment of the ERM placental villi revealed a downregulation of DiO2, N-cadherin, vimentin, fascin-1 and twist-1. The expression of E-cadherin remained unchanged in these placentae.

DISCUSSION

During placentation, DiO2 may inhibit trophoblast proliferation while facilitating their differentiation into an invasive phenotype; and that its downregulation may contribute to the shallow trophoblast invasion that precedes ERM. Hence, DiO2 is a potential therapeutic target against ERM.

Regulation of placentation by the transforming growth factor beta superfamily†

During pregnancy, there is increased expression of some cytokines at the fetal-maternal interface; and the clarification of their roles in trophoblast-endometrium interactions is crucial to understanding the mechanism of placentation. This review addresses the up-to-date reported mechanisms by which the members of the transforming growth factor beta superfamily regulate trophoblast proliferation, differentiation, and invasion of the decidua, which are the main phases of placentation. The available information shows that these cytokines regulate placentation in somehow a synergistic and an antagonistic manner; and that dysregulation of their levels can lead to aberrant placentation. Nevertheless, prospective studies are needed to reconcile some conflicting reports; and identify some unknown mediators involved in the actions of these cytokines before their detailed mechanistic regulation of human placentation could be fully characterized. The TGF beta superfamily are expressed in the placenta, and regulate the process of placentation through the activation of several signaling pathways.

The interplay between thyroid hormones and the placenta: a comprehensive review†

Thyroid hormones (THs) regulate a number of metabolic processes during pregnancy. After implantation, the placenta forms and enhances embryonic growth and development. Dysregulated maternal THs signaling has been observed in malplacentation-mediated pregnancy complications such as preeclampsia, miscarriage, and intrauterine growth restriction (IUGR), but the molecular mechanisms involved in this association have not been fully characterized. In this review, we have discussed THs signaling and its roles in trophoblast proliferation, trophoblast differentiation, trophoblast invasion of the decidua, and decidual angiogenesis. We have also explored the relationship between specific pregnancy complications and placental THs transporters, deiodinases, and THs receptors. In addition, we have examined the effects of specific endocrine disruptors on placental THs signaling. The available evidence indicates that THs signaling is involved in the formation and functioning of the placenta and serves as the basis for understanding the pathogenesis and pathophysiology of dysthyroidism-associated pregnancy complications such as preeclampsia, miscarriage, and IUGR.

Appropriate expression of P57kip2 drives trophoblast fusion via cell cycle arrest

The syncytiotrophoblast, derived from cytotrophoblast fusion, is responsible for maternal-fetal exchanges, secretion of pregnancy-related hormones, and fetal defense against pathogens. Inadequate cytotrophoblast fusion can lead to pregnancy disorders, such as preeclampsia and fetal growth restriction. However, little is known about the mechanism of cytotrophoblast fusion in both physiological and pathological pregnancy conditions. In this study, P57kip2 (P57), a cell cycle-dependent kinase inhibitor that negatively regulates the cell cycle, was found to be up-regulated during the process of syncytialization in both primary trophoblast cells and BeWo cells. Co-immunofluorescence with proliferation markers Ki67 and Cyclin-CDK factors further showed that P57 specifically localizes in the post-mitotic cytotrophoblast subtype of the early pregnancy villi. Overexpression of P57 promoted trophoblast syncytialization by arresting the cell cycle at the G1/G0 phase and inhibiting proliferation. Blocking of the cell cycle through a serum starvation culture resulted in an enhancement of cytotrophoblast fusion and the up-regulation of P57. In both spontaneous cytotrophoblast fusion and forskolin-induced BeWo cell fusion models, an initial up-regulation of P57 was observed followed by a subsequent down-regulation. These findings indicate that proper expression of P57 at cytotrophoblast differentiation nodes plays an important role in trophoblast syncytialization.

Downregulation of fascin in the first trimester placental villi is associated with early recurrent miscarriage

Inadequate trophoblast proliferation, shallow invasion and exaggerated rate of trophoblast apoptosis are implicated in early recurrent miscarriage (ERM). However, the mechanistic bases of this association have not been fully established. We aimed at investigating the involvement of fascin, an actin-bundling protein, in trophoblast activities and ERM. We found that fascin was downregulated in the cytotrophoblasts (CTBs) and distal cytotrophoblasts (DCTs) of ERM placentae. Knockdown of fascin altered cellular and nucleolar morphology, and inhibited the proliferation but increased apoptosis of trophoblastic HTR8/SVneo cells. Furthermore, fascin knockdown decreased the expression of transcription factors such as Snail1/2, Twist and Zeb1/2, mesenchymal molecules such as Vimentin and N-cadherin, and the protein expression of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and phosphorylates signal transducer and activator of transcript 3 (STAT3). Exposure of HTR-8/SVneo cells to hypoxia reoxygenation (H/R) decreased fascin expression to affect the cells' invasion. Our results indicate for the first time that the downregulation of fascin is involved in the pathogenesis of early recurrent miscarriage; and hence a potential therapeutic target against the disease.

SNP rs12794714 of CYP2R1 is associated with serum vitamin D levels and recurrent spontaneous abortion (RSA): a case-control study

PURPOSE

Vitamin D (VD) deficiency seems to be associated with the risk of recurrent spontaneous abortion (RSA). Vitamin D receptor (VDR) and cytochrome P450 family 2 subfamily R member 1 (CYP2R1) are two genes which are vital for VD metabolism and actions. However, whether single-nucleotide polymorphisms (SNPs) in these genes are correlated with the risk of RSA are poorly understood. Therefore, we aimed to characterize the relationships among VDR SNPs, CYP2R1 SNPs and RSA.

METHODS

This case-control study enrolled 75 RSA patients and 83 controls. Serum VD and some cytokines were detected with LC-MS/MS and flow cytometry, respectively. Genotyping for three SNPs of CYP2R1 (rs10741657, rs10766197 and rs12794714) and five SNPs of VDR (rs7975232, rs1544410, rs2189480, rs2228570 and rs2239179) was done with polymerase chain reaction (PCR) and high-throughput sequencing. All the data were analyzed with appropriate methods and in different models.

RESULTS

The results revealed a significant correlation between the AG genotype of CYP2R1 rs12794714 and VD levels (OR 0.686; 95% CI 0.49-0.96; p = 0.028). Besides, the AG and GG genotypes of CYP2R1 rs12794714 were markedly related to the risk of RSA (OR 52.394, 59.497; 95% CI 2.683-1023.265, 3.110-1138.367; p = 0.009, 0.007, respectively).

CONCLUSION

Our results indicate that CYP2R1 rs12794714 might be a risk factor for RSA. Hence, early screening of pregnant women for CYP2R1 rs12794714 is necessary to warrant proactive counseling and treatment against RSA.

Frequency of MED12 Mutation in Relation to Tumor and Patient's Clinical Characteristics: a Meta-analysis

Mediator complex subunit 12 (MED12) is the most frequently mutated gene in uterine leiomyomas (ULs)-with a frequency of up to 85%-suggesting that it plays key roles in the pathogenesis of ULs. However, there is no established relationship between genetic alteration and other risk factors of UL pathogenesis such as the patient's age, weight, and race. In this meta-analysis, we established an association between these risk factors and the frequency of MED12 mutation. We also established the relationship between MED12 mutation with the number and size of tumors in a patient. A systematic literature search was performed for studies published by May 2020 and performed a meta-analysis according to PRISMA guidelines. Twenty-five studies were included in the analysis, representing 3151 tissue samples. MED12 mutations were more common in Black (74.5%) as compared to White (65.8%) and Asian (53.2%) patients. There was no significant relationship between the patient's age and the frequency of mutations (OR 0.73, 95% CI 0.38 to 1.41). MED12 mutations were common in patients barring small-sized (OR 1.46, 95% CI 1.09 to 1.95) multiple (OR 0.39, 95% CI 0.17 to 0.92) tumors. For the patient's weight, studies were few and the outcome was not statistically significant. This meta-analysis provides valuable information on the relationship between the patient's clinical characteristics and frequency of MED12 mutation among patients barring ULs, which is relevant for understanding the pathogenesis of ULs.Protocol registration: The protocol was registered in PROSPERO with registration number CRD42019123439.

The Involvement of Cell Adhesion Molecules, Tight Junctions, and Gap Junctions in Human Placentation

Placentation is a major determinant of the success of pregnancy. It is regulated by several factors such as cell adhesion molecules, tight junctions, and gap junctions. The cell adhesion molecules are integrins, cadherins, immunoglobulins, nectins, and selectins. The tight junctions are composed of claudins, occludin, and junction adhesion molecule proteins while the gap junctions are composed of connexins of varying molecular weights. During placentation, some of these molecules regulate trophoblast proliferation, trophoblast fusion, trophoblast migration, trophoblast invasion, trophoblast-endothelium adhesion, glandular remodeling, and spiral artery remodeling. There is a dysregulated placental expression of some of these molecules during obstetric complications. We have, hereby, indicated the expression patterns of the subunits of each of these molecules in the various trophoblast subtypes and in the decidua, and have highlighted their involvement in physiological and pathological placentation. The available evidence points to the relevance of these molecules as distinguishing markers of the various trophoblast lineages and as potential therapeutic targets in the management of malplacentation-mediated diseases.

Ephrin and Eph receptor signaling in female reproductive physiology and pathology†

Ephrins are ligands of Eph receptors (Ephs); both of which are sorted into two classes, A and B. There are five types of ephrin-As (ephrin-A1-5) and three types of ephrin-Bs (ephrin-B1-3). Also, there are 10 types of EphAs (EphA1-10) and six types of EphBs (EphB1-6). Binding of ephrins to the Eph receptors activates signaling cascades that regulate several biological processes such as cellular proliferation, differentiation, migration, angiogenesis, and vascular remodeling. Clarification of their roles in the female reproductive system is crucial to understanding the physiology and pathology of this system. Such knowledge will also create awareness regarding the importance of these molecules in diagnostic, prognostic, and therapeutic medicine. Hence, we have discussed the involvement of these molecules in the physiological and pathological events that occur within the female reproductive system. The evidence so far suggests that the ephrins and the Eph receptors modulate folliculogenesis, ovulation, embryo transport, implantation, and placentation. Abnormal expression of some of these molecules is associated with polycystic ovarian syndrome, ovarian cancer, tubal pregnancy, endometrial cancer, uterine leiomyoma (fibroids), cervical cancer, and preeclampsia, suggesting the need to utilize these molecules in the clinical setting. To enhance a quick development of this gradually emerging field in female reproductive medicine, we have highlighted some "gaps in knowledge" that need prospective investigation.

Stomatin-like protein 2 (SLP2) regulates the proliferation and invasion of trophoblast cells by modulating mitochondrial functions

INTRODUCTION

Stomatin-like protein 2 (SLP2) is highly expressed in human first trimester trophoblast cells, but its functions in placental morpho-physiology remain unknown. This study aimed to determine the role of SLP2 in the proliferation and invasion of human first trimester trophoblast cells.

METHODS

Immunofluorescence was used to determine the expression and localization of SLP2 in normal and miscarriage human first trimester placenta. Western blot was used to determine the expression of SLP2, PCNA, Cyclin D3, N-cadherin, Vimentin, PGC1α and PPARα in HTR-8/SVneo cells. SLP2 was knocked down in the HTR-8/SVneo cells by using si-Slp2. Wound healing and migration assays were used to determine the effect of SLP2 knockdown on the migration and invasion in the HTR-8/SVneo cells. Mitochondrial membrane potential, reactive oxygen species (ROS), ATP production and biogenesis were measured to assess the effects of SLP2 knockdown on mitochondrial functions.

RESULT

SLP2 was strongly expressed in the cytotrophoblasts (CTB), syncytiotrophoblast (STB) and extravillous trophoblasts (EVT) of normal pregnancy placenta as compared to miscarriage placenta. SLP2 was highly expressed in the invasive EVT cell lines, HTR-8/SVneo and HPT-8 compared to the CTB cell line JAR. Knockdown of SLP2 significantly inhibited the migration and invasion of HTR-8/SVneo cells and placental villous explants, and repressed mitochondrial biogenesis and functions in HTR-8/SVneo cells.

DISCUSSION

Silencing of SLP2 inhibited the proliferation, migration and invasion of HTR-8/SVneo cells via the impairment of mitochondrial functions. This indicates that the downregulation of SLP2 in miscarriage placenta could be part of the pathogenesis and pathophysiology of the disease.

Bisphenol A-induced mechanistic impairment of decidualization

Decidualization is a crucial precedent to embryo implantation, as its impairment is a major contributor to female infertility and pregnancy complications. Unraveling the molecular mechanisms involved in the impairment of decidualization has been a subject of interest in the field of reproductive medicine. Evidence from several experimental settings show that exposure to bisphenol A (BPA), an endocrine-disrupting chemical, affects the expression of several molecules that are involved in decidualization. Both low and high doses of BPA impair decidualization through the dysregulation of estrogen (ER) and progesterone (PR) receptors. Exposure to low doses of BPA leads to decreased levels and activities of several antioxidant enzymes, increased activity of endothelial nitric oxide synthase (eNOS), and increased production of nitric oxide (NO) via the upregulation of ER and PR. Consequently, oxidative stress is induced and decidualization becomes impaired. On the other hand, exposure to high doses of BPA downregulates ER and PR and impairs decidualization through two distinct pathways. One is through the upregulation of early growth response-1 (EGR1) via increased phosphorylation of extracellular signal-regulated protein kinases 1 and 2; and the other is through a reduced serum glucocorticoid-induced kinase-1 (SGK1)-mediated downregulation of epithelial sodium channel-α and the induction of oxidative stress. Thus, regardless of the dose, BPA can impair decidualization to trigger infertility and pregnancy complications. This warrants the need to adopt lifestyles that will decrease the tendency of getting exposed to BPA.

THBS1 regulates trophoblast fusion through a CD36-dependent inhibition of cAMP, and its upregulation participates in preeclampsia

Preeclampsia is a pregnancy complication which threatens the survival of mothers and fetuses. It originates from abnormal placentation, especially insufficient fusion of the cytotrophoblast cells to form the syncytiotrophoblast. In this study, we found that THBS1, a matricellular protein that mediates cell-to-cell and cell-to-matrix interactions, is downregulated during the fusion of primary cytotrophoblast and BeWo cells, but upregulated in the placenta of pregnancies complicated by preeclampsia. Also, THBS1 was observed to interact with CD36, a membrane signal receptor and activator of the cAMP signaling pathway, to regulate the fusion of cytotrophoblast cells. Overexpression of THBS1 inhibited the cAMP signaling pathway and reduced the BeWo cells fusion ratio, while the effects of THBS1 were abolished by a CD36-blocking antibody. Our results suggest that THBS1 signals through a CD36-mediated cAMP pathway to regulate syncytialization of the cytotrophoblast cells, and that its upregulation impairs placental formation to cause preeclampsia. Thus, THBS1 can serve as a therapeutic target regarding the mitigation of abnormal syncytialization and preeclampsia.

Activin and inhibin signaling: From regulation of physiology to involvement in the pathology of the female reproductive system

Activins and inhibins - comprising activin A, B, AB, C and E, and inhibin A and B isoforms - belong to the transforming growth factor beta (TGFβ) superfamily. They regulate several biological processes, including cellular proliferation, differentiation and invasiveness, to enhance the formation and functioning of many human tissues and organs. In this review, we have discussed the role of activin and inhibin signaling in the physiological and female-specific pathological events that occur in the female reproductive system. The up-to-date evidence indicates that these cytokines regulate germ cell development, follicular development, ovulation, uterine receptivity, decidualization and placentation through the activation of several signaling pathways; and that their dysregulated expression is involved in the pathogenesis and pathophysiology of the numerous diseases, including pregnancy complications, that disturb reproduction. Hence, some of the isoforms have been suggested as potential biomarkers and therapeutic targets for the management of some of these diseases. Tackling the research directions highlighted in this review will enhance a detailed comprehension and the clinical utility of these cytokines.

Endometrial autophagy is essential for embryo implantation during early pregnancy

Embryo implantation is an essential and complex process in mammalian reproduction. However, little evidence has indicated the involvement of autophagy during embryo implantation. To determine the possible role of autophagy in uterine of pregnant mice during the peri-implantation stage, we first examined the expression of autophagy-related markers ATG5 and LC3 on day 4, 5, and 6 of pregnancy (D4, D5, and D6, respectively). Compared with expression on D4, downregulation of the autophagy-related markers was observed on D5 and D6, the days after the embryo attached to the receptivity endometrium. Further examination showed that autophagy-related markers ATG5, ATG12, LC3, cathepsin B, and P62 at the implantation site were significantly decreased when comparing with the inter-implantation site. Fewer number of autophagosomes at the implantation site were also observed by transmission electron microscopy. To confirm the functional role of autophagy during embryo implantation in mice, we administered the autophagy inhibitor 3-methyladenine and chloroquine to mice. After treated with 3-methyladenine, the expression of decidual markers HOXA10 and progesterone receptor were significantly reduced. Furthermore, a reduction in implantation sites and increase in the HOXA10 and PR protein levels were observed in response to chloroquine treatment. In addition, impaired uterine decidualization and dysregulation of the PR and HOXA10 protein levels was observed after autophagy inhibited by 3-methyladenine and chloroquine in in vivo artificial decidualization mouse model. In the last, LC3 and P62 were also observed in normal human proliferative, secretory, and decidua tissues. In conclusion, endometrial autophagy may be essential for embryo implantation, and it may be associated with endometrial decidualization during early pregnancy. KEY MESSAGE: • Autophagy-related markers were significantly decreased at implantation site. • Autophagy inhibition results in abnormal decidualization. • Autophagy is essential for embryo implantation.

Review of the Effects of Perinatal Exposure to Endocrine-Disrupting Chemicals in Animals and Humans

Maternal exposure to endocrine-disrupting chemicals (EDCs) is associated with long-term hormone-dependent effects that are sometimes not revealed until maturity, middle age, or adulthood. The aim of this study was to conduct descriptive reviews on animal experimental and human epidemiological evidence of the adverse health effects of in utero and lactational exposure to selected EDCs on the first generation and subsequent generation of the exposed offspring. PubMed, Web of Science, and Toxline databases were searched for relevant human and experimental animal studies on 29 October 29 2018. Search results were screened for relevance, and studies that met the inclusion criteria were evaluated and qualitative data extracted for analysis. The search yielded 73 relevant human and 113 animal studies. Results from studies show that in utero and lactational exposure to EDCs is associated with impairment of reproductive, immunologic, metabolic, neurobehavioral, and growth physiology of the exposed offspring up to the fourth generation without additional exposure. Little convergence is seen between animal experiments and human studies in terms of the reported adverse health effects which might be associated with methodologic challenges across the studies. Based on the available animal and human evidence, in utero and lactational exposure to EDCs is detrimental to the offspring. However, more human studies are necessary to clarify the toxicological and pathophysiological mechanisms underlying these effects.

The role of adiponectin in placentation and preeclampsia

Preeclampsia is not fully understood; and few biomarkers, therapeutic targets, and therapeutic agents for its management have been identified. Original investigative findings suggest that abnormal placentation triggers preeclampsia and leads to hypertension, proteinuria, endothelial dysfunction, and inflammation, which are characteristics of the disease. Because of the regulatory roles that it plays in several metabolic processes, adiponectin has become a cytokine of interest in metabolic medicine. In this review, we have discussed the role of adiponectin in trophoblast proliferation, trophoblast differentiation, trophoblast invasion of the decidua, and decidual angiogenesis, which are the major phases of placentation. Also, we have highlighted the physiological profile of adiponectin in the course of normal pregnancy. Moreover, we have discussed the involvement of adiponectin in hypertension, endothelial dysfunction, inflammation, and proteinuria. Furthermore, we have summarized the reported relationship between the maternal serum adiponectin level and preeclampsia. The available evidence indicates that adiponectin level physiologically falls as pregnancy advances, regulates placentation, and exhibits protective effects against the symptoms of preeclampsia and that while hyperadiponectinemia is evident in normal-weight preeclamptic women, hypoadiponectinemia is evident in overweight and obese preeclamptic women. Therefore, the clinical use of adiponectin as a biomarker, therapeutic target, or therapeutic agent against the disease looks promising and should be considered.

miR-21a inhibits decidual cell apoptosis by targeting Pdcd4

Decidualization of endometrial stromal cells (ESCs) accompanied with embryo implantation is a key process in mammalian reproduction. Evidence suggests that maintenance of decidual cells function is essential. As a critical part in post-transcriptional gene regulation, microRNAs (miRNAs/miR) have been confirmed to be involved in decidualization. However, whether microRNAs regulate decidual cells function has not been reported. Aiming to clarify the role and potential mechanism of miRNAs in decidual cells, artificial induced decidualization model in mice was established. There are 94 differentially expressed miRNAs (≥two-fold change) between decidualized and non-decidualized tissues, including 60 upregulated and 34 downregulated miRNAs. Of the differentially expressed miRNAs, mmu-miR-21a is up-regulated. RT-qPCR also confirmed the up-regulation of mmu-miR-21a following decidualization in vivo and in vitro, and bioinformatic analysis and luciferase activity assay revealed Pdcd4 to be the target gene of mmu-miR-21a. Inhibition of mmu-miR-21a restrained secretory function of decidual cells induced by mESCs, accompanied with increase of Pdcd4 expression and resulted in the increase of cell apoptosis. In addition, we also determined the expression of hsa-miR-21 and Pdcd4 in human proliferative endometrial tissues and decidua tissues. hsa-miR-21 showed higher expression in human decidua tissues compared with proliferative endometrial tissues, while expression of Pdcd4 was contrary to that of hsa-miR-21. Similarly, cell apoptosis increased significantly in human endometrial stromal cell line in response to inhibition of hsa-miR-21. Collectively, we conclude that mmu-miR-21a/hsa-miR-21 may play a key role in regulating the function of decidual cells by inhibiting cell apoptosis through targeting Pdcd4.

The transforming growth factor β superfamily as possible biomarkers of preeclampsia: a comprehensive review

The etiology of preeclampsia - an abnormal placentation-mediated disease - is not fully understood; and there are very few biomarkers with which to predict and diagnose it. Early prediction and diagnosis of this pathology can lead to a significant improvement in maternal and perinatal outcomes. Since members of the transforming growth factor β superfamily influence placentation, and are released from the placenta into the maternal circulatory system, several studies have investigated the involvement of these cytokines in preeclampsia and the possibility of using their serum levels as biomarkers of the disease. In this review, we have summarized the reported relationships between the levels of this superfamily of cytokines and preeclampsia. The available information indicates that altered levels of some of these cytokines are involved in the pathogenesis and pathophysiology of preeclampsia, suggesting their likelihood of serving as predictive and diagnostic biomarkers of the disease.

[Research on reform of epidemiology teaching]

Epidemiology is a traditional subject mainly based on principles and concepts, and its teaching method needs further improving to meet the requirement of the new trend of education reform. Lecture-based teaching, problem-based teaching, case-based teaching, and internet based teaching, such as flip class, massive open online course and micro-lecture, all have its own unique merits in the practice of epidemiology teaching. So the combination of traditional teaching and online teaching is the most promising mode. "Rain class" , a mixed mode, is an efficient tool to present the epidemiology case more actually in class. Thus, teaching design and application of "rain class" are worth research.

[Source tracing of the Yersinia pestis strains isolated from Heqing county, Yunnan province in 2017]

Objective: To understand the genotype of the Yersinia (Y.) pestis strains isolated from Heqing county, Yunnan province in 2017 and provide evidence for the prevention and control of plague in this area. Methods: Ten Y. pestis strains isolated from Heqing were typed by the detections of different region (DFR) and clustered regularly interspaced short palindromic repeats (CRISPRs) as well as multiple-locus variable-number tandem repeat analysis (MLVA). And the results were compared with those of the 93 Y. pestis strains from the adjacent plague foci of Heqing obtained from the established database for clustering analysis. Results: The results showed that Heqing strains had the same type of DFR (Genomovar 05) and CRISPRs (Cluster Ca7, Type 22) with isolates from the plague focus in Lijiang. Heqing strains and Lijiang strains were in the same cluster in MST and only VNTR loci N2117 and M23 of Heqing strains were different from that of Lijiang strains. Conclusion: The Y. pestis strains isolated from Heqing in 2017 were highly homogenous with the strains isolated from wild rodents in plague focus in Lijiang, and Heqing plague might be the result of further southward spread of Lijiang plague.

FOXO3a is essential for murine endometrial decidualization through cell apoptosis during early pregnancy

Embryo implantation is essential for normal pregnancy, and the process of decidualization is critical for embryo implantation. However, the mechanism of decidualization during early pregnancy is still unknown. Forkhead box O3a (FOXO3a) is the most important functional transcription factor of the forkhead box family and is a highly conserved transcription factor of apoptosis-related genes. In the mouse uterus, FOXO3a was found to be expressed regularly from Days 1-7 of early pregnancy. Upon further exploration, it was found that FOXO3a was expressed at significantly higher levels at the implantation site than at the interimplantation site on Days 5-7 of pregnancy. Under artificial decidualization, FOXO3a was highly expressed in the first and second decidual zones. After decidualization, the expression of FOXO3a was significantly increased both in vivo and vitro. In primary stromal cells, apoptosis was reduced by decreased expression of FOXO3a after inducing decidualization. Moreover, when FOXO3a-small interfering RNA was transfected into the uteri of mice, the expression of decidualization- and apoptosis-related factors was impaired. Thus, FOXO3a might play an important role in decidualization during early pregnancy, and cell apoptosis might be one of pathways for FOXO3a-regulated decidualization.

Methylated oligonucleotide (MON)-induced promoter hypermethylation is associated with repression of CDH1 expression and contributes to the migration and invasion of human trophoblast cell lines

DNA cytosine-5 methylation plays a vital role in regulating the expression of E-cadherin, which is encoded by the CDH1 gene. In this study, we characterised the DNA methylation and expression pattern of CDH1 in an extravillous trophoblast cell line (HTR-8/SVneo) and two trophoblast cell lines -- JEG-3 and JAR. Promoter hypermethylation with reduced E-cadherin expression in HTR-8/SVneo cells and promoter hypomethylation with increased E-cadherin expression in JEG-3 and JAR cells were observed. Demethylation treatment significantly restored E-cadherin expression, contributing to decreases in the motility and invasiveness of HTR-8/SVneo cells. Sense-methylated oligonucleotides (MONs) labelled with Cy5 and complementary to a region of the human CDH1 promoter were designed, with the cytosines in 5'-cytosine-phosphate-guanine-3' (CpG) dinucleotides being replaced by methylated cytosines. Following MON transfection into JEG-3 cells, the level of CDH1 promoter DNA methylation as well as cell motility and invasiveness were increased and gene expression was significantly repressed. Our results indicate that MON-mediated DNA methylation of the CDH1 promoter and subsequent alterations in gene expression may contribute to trophoblast motility and invasion, suggesting a potential method for controlling the biological function of trophoblasts in vitro through epigenetic modification.

Bisphenol A exposure promotes HTR-8/SVneo cell migration and impairs mouse placentation involving upregulation of integrin-β1 and MMP-9 and stimulation of MAPK and PI3K signaling pathways

In this study, we investigated the effect of Bisphenol A (BPA), an endocrine-disrupting chemical, on the migration of human trophoblasts and mouse placentation by using the primary extravillous trophoblast (EVT) and its cell line HTR-8/SVneo, villous explant cultures, and pregnant mice. BPA increased EVT motility and the outgrowth of villous explants in a dose-dependent manner. BPA also increased the protein levels of integrin-β1 and matrix metalloproteinase (MMP)-9 in human EVTs. Low-dose BPA (≤50 mg) increased the protein levels of MMP-9 and MMP-2 as well as integrin-β1 and integrin-α5 in mouse placenta and decreased the proportion of the labyrinth and spongiotrophoblast layers. Inhibitors of mitogen-activated protein kinase (MAPK) U0126 and phosphatidylinositol-3-kinases (PI3K) LY294002 reversed the protein levels of integrin-β1 and MMP-9 as well as the migratory ability induced by BPA. In conclusion, these results indicated that BPA can enhance trophoblast migration and impair placentation in mice by a mechanism involving upregulation of integrin(s) and MMP(s) as well as the stimulation of MAPK and PI3K/Akt (protein kinase B) signaling pathways.

nm23 regulates decidualization through the PI3K-Akt-mTOR signaling pathways in mice and humans

STUDY QUESTION

Does nm23 have functional significance in decidualization in mice and humans?

SUMMARY ANSWER

nm23 affects decidualization via the phosphoinositide 3 kinase/mammalian target of rapamycin (PI3K-Akt-mTOR) signaling pathways in mouse endometrial stromal cells (ESCs; mESCs) and human ESCs.

WHAT IS KNOWN ALREADY

The function of nm23 in suppressing metastasis has been demonstrated in a variety of cancer types. nm23 also participates in the control of DNA replication and cell proliferation and differentiation.

STUDY DESIGN, SIZE AND DURATION

We first analyzed the expression profile of nm23 in mice during early pregnancy (n = 6/group), pseudopregnancy (n = 6/group) and artificial decidualization (n = 6/group) and in humans during the menstrual cycle phases and the first trimester. We then used primary cultured mESCs and a human ESC line, T-HESC, to explore the hormonal regulation of nm23 and the roles of nm23 in in vitro decidualization, and as a possible mediator of downstream PI3K-Akt-mTOR signaling pathways.

PARTICIPANTS/MATERIALS, SETTINGS AND METHODS

We evaluated the dynamic expression of nm23 in mice and humans using immunohistochemistry, western blot and real-time quantitative RT-PCR (RT-qPCR). Regulation of nm23 by steroid hormones was investigated in isolated primary mESCs and T-HESCs by western blot. The effect of nm23 knockdown (using siRNA) on ESC proliferation was analyzed by 5-ethynyl-2'-deoxyuridine staining (EdU) and proliferating cell nuclear antigen protein (PCNA) expression. The influence of nm23 expression on the differentiation of ESCs was determined by RT-qPCR using the mouse differentiation markers decidual/trophoblast PRL-related protein (dtprp, also named prl8a2) and prolactin family 3 subfamily c member 1 (prl3c1) and the human differentiation markers insulin-like growth factor binding protein 1 (IGFBP1) and prolactin (PRL). The effects of nm23 siRNA (si-nm23) and the PI3K inhibitor LY294002 on the downstream effects of nm23 on the PI3K-Akt-mTOR signaling pathway were estimated by western blot.

MAIN RESULTS AND THE ROLE OF CHANCE

NM23-M1 was specifically expressed in the decidual zone during early pregnancy and in artificially induced deciduoma, and NM23-H1 was strongly expressed in human first trimester decidua. The expression of nm23 was upregulated by oestradiol and progesterone (P < 0.05 versus control) in vitro in mESCs and T-HESC, and this was inhibited by their respective receptor antagonists, ICI 182,780 and RU486. Mouse and human nm23 knockdown decreased ESC proliferation and differentiation (P < 0.05 versus control). The PI3K-Akt-mTOR signaling pathways were downstream mediators of nm23 in mESCs and T-HESCs decidualization.

LIMITATIONS AND REASONS FOR CAUTION

Whether the nm23 regulates decidualization via the activation of AMPK, RAS, PKA, STAT3 or other signaling molecules remains to be determined. The role of nm23 in decidualization was tested in vitro only.

WIDER IMPLICATIONS OF THE FINDINGS

Results demonstrate that nm23 plays a vital role in decidualization in mice and humans and that nm23 gene expression is hormonally regulated. The downregulation of nm23 in decidua during the first trimester may be associated with infertility in women.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the National Natural Science Foundation of China (grant nos. 81370731, 31571551 and 31571190), the Science and Technology Project of Chongqing Education Committee (KJ130309), open funding by the Chongqing Institute for Family Planning (1201) and the Excellent Young Scholars of Chongqing Medical University (CQYQ201302). The authors have no conflicts of interest to declare.

DNA methylation-associated repression of MEST/PEG1 expression contributes to the invasion of extravillous trophoblast cells

INTRODUCTION

The invasion of extravillous cytotrophoblasts (EVTs) into the maternal uterine decidua and vasculature is critical for human placenta development and pregnancy maintenance. The imprinted gene MEST/PEG1 has been implicated in trophoblast development; however, the role of MEST in EVT invasion and the accompanying early pregnancy complications are not fully understood.

METHODS

Western blot, immunofluorescence and immunohistochemistry were used to detect MEST protein expression and localization by using antibodies recognize 2 reported isoforms. Specific small interference RNA (siRNA) targeting both of the MEST isoforms was applied to silence MEST expression in extravillous explants and HTR8/SVneo cells. Cell invasion and migration were assessed using the Matrigel invasion, Transwell migration assay and the xCELLigence system. Promoter DNA methylation was examined using bisulfite-sequencing polymerase chain reaction (BSP).

RESULTS

MEST protein was highly expressed in EVTs in the first trimester placenta and in the invasive EVT cell lines HTR-8/Svneo and HPT-8. Weak MEST expression was found in cytotrophoblasts (CTBs) and the choriocarcinoma-derived CTB cell line JEG-3. The specific siRNA knockdown of MEST expression significantly reduced HTR-8/Svneo cell invasion and migration as well as extravillous explant outgrowth, which were associated with the downregulation of Twist, N-cadherin and Vimentin. Decreased MEST protein expression with isoform 2 promoter hypermethylation was observed in the placentas of missed abortions, suggesting a possible pathological mechanism of missed abortion.

CONCLUSIONS

Suppressed expression of MEST was associated with its isoform 2 promoter hypermethylation ex vivo placenta tissues and in vitro cultured EVT cell lines. The present results provide a possible pathological mechanism of missed abortion.

[Isolation and biological characteristics on Yersinia pestis phage YP060]

OBJECTIVE

To isolate and identify the characteristics of Yersinia pestis phage YP060 from mice nests in Yunnan plague focus.

METHODS

Phage YP060 was isolated from Yunnan plague focus by double-layer agar plate method with attenuated vaccine Yersinia pestis strain EV76 as the host bacterium. Phage particle was observed under the electron microscope while biological properties of phage YP060 including lytic capacity, host spectrum, optimal multiplicity of infection (MOI), one-step growth curve, sensitivity to temperature, pH, ultraviolet ray and chloroform etc. were identified.

RESULTS

The particles of phage YP060 presented tadpoles-like features, with optimal multiplicity of infection as 0.1. Latent period and burst period appeared as 50 min and 80 min, respectively. The phage endured the temperature between 30-50 ℃, and it contained a stronger lysis activities in a range of pH 5 to 10. Phage YP060 was sensitive to ultraviolet rays but insensitive to chloroform while presented special lysic ability to Yersinia pestis.

CONCLUSION

Yersinia pestis phage YP060 was isolated for the first time from mice nests in plague natural focus in China. Our findings related to narrow host spectrum and stronger lysis activities.

Activation of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor gene expression following DNA demethylation in placental choriocarcinoma and transformed cell lines

We characterised DNA methylation and gene expression of four tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors DR4, DR5, DcR1 and DcR2 in three choriocarcinoma (JAR, JEG-3, BeWo) and two transformed (HTR-8/SVneo and HPT-8) cell lines. DR4 mRNA was detected in JAR, JEG-3, BeWo and HTR-8/SVneo cells, whereas DR5 was present in all detected cells. DcR1 transcripts were expressed only in JAR, JEG-3 and BeWo cells, whereas DcR2 transcripts were detected only in HTR-8/SVneo and HPT-8 cells. Hypermethylated DR4 promoter was observed in JAR, JEG-3, BeWo and HTR-8/SVneo cells, hypermethylated DcR1 promoter in HTR-8/SVneo and HPT-8 cells and hypermethylated DcR2 promoter in JAR, JEG-3 and BeWo cells. Restoration of DR4, DcR1 and DcR2 expression with decreased DNA methylation of these genes was induced by the DNA demethylation agent 5-aza-2'-deoxycytidine (5-aza-CdR) in trophoblast cells, whereas DR5 expression did not exhibit any change. Significant negative correlation between the expression and DNA methylation of these genes was also observed. In all tested cell lines, only HPT-8 demonstrated sensitivity to TRAIL-induced apoptosis. Combined treatment with 5-aza-CdR and TRAIL resulted in apoptosis in JAR, JEG-3, BeWo and HTR-8/SVneo cells but not in HPT-8 cells. The results indicate that DNA methylation is associated with TRAIL receptor expression and might be involved in trophoblast apoptosis.