Features, Potential Invasion Pathways, and Reproductive Health Risks of Microplastics Detected in Human Uterus.

Microplastics (MPs) are ubiquitous in global ecosystems and may pose a potential risk to human health. However, critical information on MP exposure and risk to female reproductive health is still lacking. In this study, we characterized MPs in human endometrium and investigated their size-dependent entry mode as well as potential reproductive toxicity. Endometrial tissues of 22 female patients were examined, revealing that human endometrium was contaminated with MPs, mainly polyamide (PA), polyurethane (PU), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyethylene (PE), ranging from 2-200 µm in size. Experiments conducted in mice demonstrated that the invasion of the uterus by MPs was modulated either through diet-blood circulation (micrometer-sized particles) or via the vagina-uterine lacuna mode (larger particles reaching a size of 100 µm. Intravenous exposure to MPs resulted in reduced fertility and abnormal sex ratio in mouse offspring (P < 0.05). After 3.5 months of intragastric exposure, there was a significant inflammatory response in the endometrium (P < 0.05), confirmed by embryo transfer as a uterine factor leading to decreased fertility. Furthermore, human endometrial organoids cultured with MPs in vitro exhibited significantly apoptotic responses and disrupted growth patterns (P < 0.01). These findings raise significant concerns regarding MP contamination in the human uterus and its potential effects on reproductive health.

Role of polyphenols in remodeling the host gut microbiota in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a common reproductive and metabolic condition in women of childbearing age and a major cause of anovulatory infertility. The pathophysiology of PCOS is complex. Recent studies have reported that apart from hyperandrogenism, insulin resistance, systemic chronic inflammation, and ovarian dysfunction, gut microbiota dysbiosis is also involved in PCOS development and may aggravate inflammation and metabolic dysfunction, forming a vicious cycle. As naturally occurring plant secondary metabolites, polyphenols have been demonstrated to have anticancer, antibacterial, vasodilator, and analgesic properties, mechanistically creating putative bioactive, low-molecular-weight metabolites in the human gut. Here, we summarize the role of gut microbiota dysbiosis in the development of PCOS and demonstrate the ability of different polyphenols - including anthocyanin, catechins, and resveratrol - to regulate gut microbes and alleviate chronic inflammation, thus providing new insights that may assist in the development of novel therapeutic strategies to treat women with PCOS.

Circ_0115118 regulates endometrial functions through the miR-138-1-3p/WDFY2 axis in patients with PCOS†.

To investigate the expression profiles of circular RNAs (circRNAs) in the endometria of women with polycystic ovary syndrome (PCOS) and to explore the role of aberrant circ_0115118 expression in endometrial dysfunction in patients with PCOS. CircRNA microarray hybridization and bioinformatic analyses were performed to determine the expression patterns of circRNAs in the endometria of patients with or without PCOS, the expression of target circRNA was evaluated by real-time polymerase chain reaction (PCR). Cell counting kit-8 and Transwell assays were used to detect cellular proliferative, invasive, and migratory capacities. The influence of the circRNA on decidualization was explored by real-time PCR. Animal models were established to investigate the regulatory effect of the circRNA on embryo implantation. Downstream microRNAs and genes were predicted using bioinformatic websites and verified by dual-luciferase reporter assays, real-time PCR, and western blotting. In the endometria of patients with PCOS, there were 113 differentially expressed circRNAs in the secretory phase and 1119 differentially expressed circRNAs in the proliferative phase. The expression of circ_0115118 was significantly higher in endometrial stromal cells during the proliferative phase in patients with PCOS, leading to inhibition of cellular mobilization and embryo implantation. In addition, circ_0115118 exerted effects by sponging miR-138-1-3p, subsequently increasing the expression of WD repeat and FYVE domain-containing protein 2 (WDFY2). Circ_0115118 expression is dysregulated in the endometria of patients with PCOS and adversely affects endometrial function. Our findings reveal that circ_0115118 may be a potential therapeutic target to improve pregnancy outcomes in women with PCOS.

Abnormal Endometrial Receptivity and Oxidative Stress in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women of childbearing age. Individual heterogeneity is evident, and the prevalence rate ranges between 6 and 15% globally. The prevalence rate of PCOS in Chinese women of childbearing age is 5.6%. The main manifestations are infertility, sparse menstruation, irregular vaginal bleeding, long-term endometrial hyperplasia, and endometrial cancer. PCOS is often associated with hyperandrogenemia, insulin resistance, hyperinsulinemia, obesity, metabolic syndrome, and intestinal flora disorder. Although there have been many studies in the past, the underlying pathophysiological mechanism of the disease is still unclear. Studies have shown that PCOS diseases and related complications are closely related to local oxidative stress imbalance in the endometrium, leading to poor endometrial receptivity and effects on pregnancy. Previous reviews have mainly focused on the abnormal mechanism of ovarian oxidative stress in women with PCOS, while reviews on endometrial receptivity and oxidative stress are relatively insufficient. This study reviews the abnormal cellular and molecular mechanisms of oxidative stress due to comorbidities in women with PCOS, leading to a downregulation of endometrial receptivity.

Ginsenoside Rb1 inhibits oxidative stress-induced ovarian granulosa cell injury through Akt-FoxO1 interaction.

Ginsenoside Rb1 shows a strong antioxidant effect and has potential activation effects on Akt. The aim of the present study was to investigate the protective effect of Rb1 on age-related ovarian granulosa cell injury. Ovarian granulosa cells (GCs) were obtained from 50 young women (≤30 years) and 50 aged women (≥38 years) at an IVF center. Young and aged ICR mice were administered with or without Rb1 (10 mg kg-1, i.p.) for 2 weeks. The protective effects of Rb1 were investigated and the role of Rb1 on the modulation of Akt-FoxO1 interaction was determined with immunofluorescence, Western blotting, immunoprecipitation, siRNA silencing and pharmacological inhibitor. Rb1 effectively decreased LDH and MDA, and reversed the apoptotic-related protein levels in hGL cells from old patients. Similar results were found in mice. In addition, the mitochondrial membrane potential was restored and the overaccumulation of ROS was reversed by Rb1. Rb1 preserved peroxide-impaired Akt activation, to some extent, by increasing phosphorylation at Ser473. Rb1 also facilitated p-Akt binding to FoxO1 and promoted the phosphorylation of FoxO1. SiRNA silencing of Akt, Akt inhibitor LY294002, and FoxO1 inhibitor AS1842856 attenuated the effects of Rb1. Ginsenoside Rb1 inhibits age-related GCs oxidative damage by activating Akt phosphorylation at Ser473 and by further interaction with FoxO1.

An Altered Microbiota in the Lower and Upper Female Reproductive Tract of Women with Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is a complex multifactorial disease. Recently, the microbiota of the female reproductive tract, as an emerging factor in RSA, has gradually attracted the attention of many clinical researchers. Here, we reported that the microbiota of the lower and upper female reproductive tracts from patients with RSA showed no significant differences in alpha diversity compared to that of controls. Beta diversity was significantly higher in the RSA group than in the control group in the vaginal microbiota (P = 0.036), cervical microbiota (P = 0.010) and microbiota from uterine lavage fluid (P = 0.001). In addition, dramatic decreases in gamma interferon and interleukin-6 cytokine levels were observed in the RSA group. In conclusion, our data suggested altered microbial biodiversity in the vagina, cervix and uterine lavage fluid in the RSA group. Alterations in the microbiota in the uterine cavity could be associated with altered cytokine levels, which might be a risk factor for RSA pathogenesis. Moreover, the microbiota composition differed markedly from the lower genital tract to the uterine cavity, and the microbiota in the uterine cavity also distinctly varied between endometrial tissue and uterine lavage fluid in the RSA group. Hence, sampling with these two methods simultaneously allowed a more comprehensive perspective of microbial colonization in the uterine cavity. IMPORTANCE As an obstacle to pregnancy, recurrent spontaneous abortion (RSA) can be caused by a variety of factors, and a current understanding of the etiology of RSA is still lacking; half of cases have an unknown cause. A substantial fraction of patients show no improvement after treatment. Since the microbiota of the female reproductive tract has been proposed as an emerging factor in RSA patients, further investigation is needed to provide guidance for clinical therapy. In general, this is the first report describing the distinct alterations of the vaginal, cervical, and uterine microbiota in RSA, not just that in the vagina. Furthermore, another major strength of this study derived from the further in-depth investigation and analysis of the characteristics of the microbiota colonizing the upper female genital tract in RSA, which provided a more comprehensive view for investigating the uterine microbiota.

Heterozygous FMN2 missense variant found in a family case of premature ovarian insufficiency.

BACKGROUND: Premature ovarian insufficiency (POI) plagues 1% of women under 40, while quite a few remain an unknown cause. The development of sequencing has helped find pathogenic genes and reveal the relationship between DNA repair and ovarian reserve. Through the exome sequencing, our study targets screening out the possible POI pathogenic gene and variants in a Chinese family and 20 sporadic POI patients, preliminarily exploring the functional impact and finding out potential linkages between the gene and POI. RESULTS: The whole exome sequencing suggested a novel FMN2 heterozygous variant c.1949C > T (p.Ser650Leu) carried by all three patients in a Chinese family and another c.1967G > A(p.Arg656His) variant in a sporadic case. Since no FMN2 missense mutation is reported for causing human POI, we preliminarily assessed p.Ser650Leu variant via cross-species alignment and 3D modeling and found it possibly deleterious. A series of functional evidence was consistent with our hypothesis. We proved the expression of FMN2 in different stages of oocytes and observed a statistical difference of chromosomal breakages between the POI patient carrying p.Arg656His variant and the health control (p = 0.0013). Western Blot also suggested a decrease in FMN2 and P21 in the mutant type and an associated increase in H2AX. The p.Arg656His variant with an extremely low frequency also indicated that the gene FMN2 might play an essential role in the genetic etiology of POI. To the best of our knowledge, this is the first POI report on missense variants of FMN2. CONCLUSION: This finding indicates a novel gene possibly related to POI and sheds lights on the study of FMN2.

Efficacy and safety of autologous adipose tissue-derived stromal vascular fraction in patients with thin endometrium: a protocol for a single-centre, longitudinal, prospective self-control study.

INTRODUCTION: Endometrial thickness is an important parameter to evaluate endometrial receptivity. An appropriate endometrial thickness is necessary for both embryo implantation and maintaining normal pregnancy. Women with thin endometrium are one of the critical challenges in the clinic, and current therapeutic strategies for thin endometrium remain suboptimal. The stromal vascular fraction (SVF) derived from adipose tissue contains a variety of cells, mainly adipose-derived stem/stromal cells and adipose cells. Recently, adipose tissue-derived SVF showed tremendous potential for treating thin endometrium due to its capacity to repair and regenerate tissues. The application of SVF in animal models for treating thin endometrium has been investigated. However, limited evidence has demonstrated the efficacy and safety of autologous SVF in patients with thin endometrium. METHODS AND ANALYSIS: This study is a single-centre, longitudinal, prospective self-control study to investigate the preliminary efficacy and safety of autologous SVF in improving the pregnancy outcome of infertile patients with thin endometrium. Thirty patients diagnosed with thin endometrium will be recruited based on the inclusion and exclusion criteria. The SVF suspension will be transferred into the uterine cavity via an embryo transfer catheter. Then, comparisons between pretreatment and post-treatment will be analysed, and the outcomes, including endometrial thickness, menstrual volume and duration, frequency and severity of adverse events and early pregnancy outcomes, will be measured within a 3-month follow-up, while late pregnancy outcomes and their offspring will be followed up via telephone for 2 years. The proportion of patients with improved symptoms will be calculated and compared. ETHICS AND DISSEMINATION: This study was approved by the Ethics Committee of Peking University Third Hospital (reference number: REC2020-165). Written informed consent will be provided for patients before being included. The results will be presented at academic conferences and a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ChiCTR2000035126.

Mutant Zp1 impedes incorporation of ZP3 and ZP4 in the zona pellucida, resulting in zona absence and female infertility in rats†.

The zona pellucida (ZP) plays vital roles in reproductive processes including oogenesis, fertilization, and preimplantation development. Both human and rat ZP consist of four glycoproteins, called ZP1, ZP2, ZP3, and ZP4. Our previous research reported a novel Zp1 mutation in cases of human infertility, associated with an abnormal phenotype involving the absence of the ZP. Here, we developed a homologous rat strain to investigate the pathogenic effect. The ovaries of homozygous (Zp1MT/MT) females possessed both growing and fully grown oocytes; the oocytes completely lacked a ZP, but ZP1 was detectable inside the cytoplasm. Only 1-2 eggs were recovered from oviducts of superovulated Zp1MT/MT females, while an average of 21 eggs were recovered from superovulated Zp1WT/WT per female. The eggs of Zp1MT/MT females were not surrounded by a ZP and lost their fertilization capacity in vitro. Zp1MT/MT females mated with wild-type males failed to become pregnant. Studies in 293T cells showed that mutant Zp1 resulted in a truncated ZP1 protein, which might be intracellularly sequestered and interacted with wild-type ZP3 or ZP4. Our results suggest that the Zp1 point mutation led to infertility and loss of the ZP in oocytes in rats.

Network-based Transcriptome-wide Expression Study for Postmenopausal Osteoporosis.

PURPOSE: Menopause is a crucial physiological transition during a woman's life, and it occurs with growing risks of health issues like osteoporosis. To identify postmenopausal osteoporosis-related genes, we performed transcriptome-wide expression analyses for human peripheral blood monocytes (PBMs) using Affymetrix 1.0 ST arrays in 40 Caucasian postmenopausal women with discordant bone mineral density (BMD) levels. METHODS: We performed multiscale embedded gene coexpression network analysis (MEGENA) to study functionally orchestrating clusters of differentially expressed genes in the form of functional networks. Gene sets net correlations analysis (GSNCA) was applied to assess how the coexpression structure of a predefined gene set differs in high and low BMD groups. Bayesian network (BN) analysis was used to identify important regulation patterns between potential risk genes for osteoporosis. A small interfering ribonucleic acid (siRNA)-based gene silencing in vitro experiment was performed to validate the findings from BN analysis. RESULT: MEGENA showed that the "T cell receptor signaling pathway" and the "osteoclast differentiation pathway" were significantly enriched in the identified compact network, which is significantly correlated with BMD variation. GSNCA revealed that the coexpression structure of the "Signaling by TGF-beta receptor complex pathway" is significantly different between the 2 BMD discordant groups; the hub genes in the postmenopausal low and high BMD group are FURIN and SMAD3 respectively. With siRNA in vitro experiments, we confirmed the regulation relationship of TGFBR2-SMAD7 and TGFBR1-SMURF2. MAIN CONCLUSION: The present study suggests that biological signals involved in monocyte recruitment, monocyte/macrophage lineage development, osteoclast formation, and osteoclast differentiation might function together in PBMs that contribute to the pathogenesis of postmenopausal osteoporosis.

Novel PMM2 missense mutation in a Chinese family with non-syndromic premature ovarian insufficiency.

PURPOSE: This study sought to identify a disease-related gene in a consanguineous Chinese family in which there were two premature ovarian insufficiency (POI) sisters. METHOD: We used whole-exome sequencing and Sanger sequencing to identify the disease-causing gene. Results were verified using an assay of mutant protein and in silico analyses. RESULT: We identified a novel missense mutation (NM_000303: c.556G>A, p.Gly186Arg) in the PMM2 gene. The two sisters suffer from premature ovarian insufficiency (POI) only and have no other symptoms of congenital disorder of glycosylation type-1a (CDG-Ia). We found that the enzymic activity of the mutant PMM2 protein was reduced by 55.21% (p < 0.05) when compared with wild type, and many in silico tools suggested the mutation is disease-related. CONCLUSION: This particular gene modification results in changes in activity of phosphomannomutase modification, which could lead to PMM2-CDG-Ia with an uncommon phenotype.

Influence of mouse defective zona pellucida in folliculogenesis on apoptosis of granulosa cells and developmental competence of oocytes†.

Zona pellucida (ZP), which enwraps the oocyte during folliculogenesis, initially forms in the primary follicle and plays an important role in female fertility. Here, we investigated a mouse strain ("mutant mice" for short) carrying two types of ZP defects in folliculogenesis, i.e., ZP thinned (but intact) and ZP cracked, caused by targeted mutation in the Zp1 gene. Using this mutant mouse strain and wild-type mouse as control, we studied the effects of the ZP defects on the development of oocytes and granulosa cells during folliculogenesis. For each ZP defect, we examined the morphology of transzonal projections and apoptosis of granulosa cells in the corresponding growing follicles, as well as the morphology of corresponding ovulated eggs and their abilities to develop into viable individuals. Our results suggested that ZP integrity rather than thickness or porosity is crucial for preventing the ectopia of granulosa cells, maintaining adequate routine bilateral signaling between oocyte and surrounding granulosa cells, and thus for ensuring the survival of granulosa cells and the establishment of the full developmental competence of oocytes. This is the first study to elucidate the effects of different degrees of ZP defects caused by the same gene mutation, on the apoptosis of granulosa cells and developmental competence of oocytes, and to explore the potential mechanisms underlying these effects.