A nationwide survey of diagnostic procedures for abnormal uterine bleeding in Japan.

AIM: To clarify the diagnostic process of the causative disease of abnormal uterine bleeding (AUB) in Japan according to the International Federation of Gynecology and Obstetrics AUB diagnostic system. METHODS: Patients diagnosed with AUB were included in a nationwide survey of AUB conducted during any 2-week period between December 2019 and January 2020. The second survey included information on patient background, AUB symptoms, examinations for diagnosing AUB, the order in which they were performed, and the causative diseases of AUB. RESULTS: Correspondence analysis showed an association between hormonal testing, hysterosalpingography, and magnetic resonance imaging (MRI) in patients with amenorrhea, and heavy menstrual bleeding was strongly correlated with various examinations, such as coagulation tests, pelvic MRI, and endometrial cytology or biopsy. The results also indicated that each AUB causative disease can be diagnosed based on a specific examination profile. CONCLUSION: We clarified the process of diagnosing the causative disease of AUB in our country and determined that it was mainly diagnosed by imaging and pathological examination in cases of structural disease. The high rate of AUB-E and the low rate of AUB-C are possibly associated with specific examination trends in Japan. The results of this study will be useful for the development of a standard protocol for AUB diagnosis in our country.

Diagnosis of abnormal uterine bleeding based on the FIGO classification: A systematic review and expert opinions.

AIM: To present evidence- and consensus-based recommendations for the diagnosis abnormal uterine bleeding. METHODS: A literature search for the diagnosis of abnormal uterine bleeding was systematically conducted in PubMed from its inception to May 2024 to identify meta-analyses, reviews, randomized controlled trials, and clinical trials, followed by an additional systematic search using keywords. Based on this evidence, an expert panel developed background, clinical, and future research questions. RESULTS: Based on a systematic search and the collected evidence, we developed five background questions, three clinical questions, and one future research question, with recommendations and/or statements. Evidence and recommendations are provided for clinical questions. Additionally, we developed a flowchart for diagnosis showing the steps of the examinations to be performed. CONCLUSION: The flowchart and nine recommendations/statements specify an efficient diagnostic procedure to differentiate abnormal causative diseases of uterine bleeding optimized for actual Japanese situations.

Analysis of cell-cell interaction between mural granulosa cells and cumulus granulosa cells during ovulation using single-cell RNA sequencing data of mouse ovary.

Purpose: We investigated the interactions between mural granulosa cells (MGCs) and cumulus granulosa cells (CGCs) during ovulation after the LH surge. Methods: We performed clustering, pseudotime, and interactome analyses utilizing reported single-cell RNA sequencing data of mouse ovary at 6 h after eCG-hCG injection. Results: Clustering analysis classified granulosa cells into two distinct populations, MGCs and CGCs. Pseudotime analysis divided granulosa cells into before and after the LH surge, and further divided them into two branches, the ovulatory MGCs and the ovulatory CGCs. Interactome analysis was performed to identify the interactions between MGCs and CGCs. Twenty-six interactions were acting from CGCs toward MGCs, involving ovulation and steroidogenesis. Thirty-six interactions were acting from MGCs toward CGCs, involving hyaluronan synthesis. There were 25 bidirectional interactions, involving the EGFR pathway. In addition, we found three novel interactions: Ephrins-Ephs pathway and Wnt-Lrp6 pathway from CGCs to MGCs, associated with steroidogenesis and lipid transport, respectively, and TGF-ß-TGFBR1 pathway from MGCs to CGCs, associated with hyaluronan synthesis. Conclusions: MGCs and CGCs interact with each other in the preovulatory follicle after the LH surge, and their interactions have roles in corpus luteum formation, oocyte maturation, and follicle rupture.

Transcriptional coactivator PGC-1α contributes to decidualization by forming a histone-modifying complex with C/EBPß and p300.

We previously reported that CCAAT/enhancer-binding protein beta (C/EBPß) is the pioneer factor inducing transcription enhancer mark H3K27 acetylation (H3K27ac) in the promoter and enhancer regions of genes encoding insulin-like growth factor-binding protein-1 (IGFBP-1) and prolactin (PRL) and that this contributes to decidualization of human endometrial stromal cells (ESCs). Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α; PPARGC1A) is a transcriptional coactivator known to regulate H3K27ac. However, although PGC-1α is expressed in ESCs, the potential role of PGC-1α in mediating decidualization is unclear. Here, we investigated the involvement of PGC-1α in the regulation of decidualization. We incubated ESCs with cAMP to induce decidualization and knocked down PPARGC1A to inhibit cAMP-induced expression of IGFBP-1 and PRL. We found cAMP increased the recruitment of PGC-1α and p300 to C/EBPß-binding sites in the promoter and enhancer regions of IGFBP-1 and PRL, corresponding with increases in H3K27ac. Moreover, PGC-1α knockdown inhibited these increases, suggesting PGC-1α forms a histone-modifying complex with C/EBPß and p300 at these regions. To further investigate the regulation of PGC-1α, we focused on C/EBPß upstream of PGC-1α. We found cAMP increased C/EBPß recruitment to the novel enhancer regions of PPARGC1A. Deletion of these enhancers decreased PGC-1α expression, indicating that C/EBPß upregulates PGC-1α expression by binding to novel enhancer regions. In conclusion, PGC-1α is upregulated by C/EBPß recruitment to novel enhancers and contributes to decidualization by forming a histone-modifying complex with C/EBPß and p300, thereby inducing epigenomic changes in the promoters and enhancers of IGFBP-1 and PRL.

Genome-wide analysis of histone modifications that underlie the dynamic changes in gene expression during decidualization in human endometrial stromal cells.

Human endometrial stromal cells (hESCs) undergo a differentiation process with dramatic changes in cell functions during the menstrual cycle, which is called decidualization. This is an important event for implantation of the embryo and successful pregnancy. Defective decidualization can cause implantation failure, miscarriage, and unexplained infertility. A number of genes are upregulated or downregulated during decidualization. Recent studies have shown that epigenetic mechanisms are involved in the regulation of decidualization-related genes and that histone modifications occur throughout the genome during decidualization. The present review focuses on the involvement of genome-wide histone modifications in dramatic changes in gene expression during decidualization. The main histone modifications are the increases of H3K27ac and H3K4me3, which activate transcription. C/EBPß works as a pioneer factor throughout the genome by recruiting p300. This is the main cause of the genome-wide acetylation of H3K27 during decidualization. Histone modifications were observed in both the proximal promoter and distal enhancer regions. Genome editing experiments show that the distal regions have transcriptional activities, which suggests that decidualization induces the interactions between proximal promoter and distal enhancer regions. Taken together, these findings show that gene regulation during decidualization is closely associated with genome-wide changes of histone modifications. This review provides new insights regarding the cases of implantation failure in terms of decidualization insufficiency owing to epigenetic dysregulation, and may lead to novel treatment options for women with implantation failure.

Text mining in a literature review of abnormal uterine bleeding according to the FIGO classification.

AIM: Abnormal uterine bleeding, as proposed in 2007, is defined as unexpected uterine bleeding in women of reproductive age; the cause of the bleeding is categorized using the PALM-COEIN system. Identifying the diagnostic and treatment modalities for each cause might be intriguing. To summarize the options for abnormal uterine bleeding assessment, we employed text-mining analysis for each of its causes. METHODS: We analyzed abstracts based on PALM-COEIN from PubMed and Web of Science in March 2022. The literature was divided into categories; topics about the disorders were retrieved, and covalent network analysis was conducted to find information for evaluating abnormal uterine bleeding. RESULTS: Diagnostic approaches for PALM included histological and image analysis, including computerized tomography, magnetic resonance imaging, sonography, and hysteroscopy. The therapeutic approaches varied according to the cause. Diagnostic approaches for COEIN were mostly medical history interviews and blood sampling, and the therapeutic approaches for COEIN were ablation, hysteroscopy, and hormonal treatment. The PALM-COEIN classification co-occurrence search revealed each cause's diagnostic procedures, symptoms, and treatment procedures. CONCLUSION: Our text-mining methodology revealed comprehensive insights, important study themes, and clinical trends for abnormal uterine bleeding. A tailored approach to medical realities is required for treating abnormal uterine bleeding properly.

National survey of abnormal uterine bleeding according to the FIGO classification in Japan.

AIM: To investigate the status of abnormal uterine bleeding (AUB) in Japan using the International Federation of Gynecology and Obstetrics (FIGO) classification (AUB system 1 and 2; PALM-COEIN) and to clarify the relationship between AUB symptoms and the diseases causing AUB. METHODS: In a nationwide study, we enrolled first-time patients who visited target facilities during two consecutive weeks from December 1, 2019 to January 31, 2020. The FIGO classification was used to investigate patients with symptoms and causative diseases of AUB. Based on the proportion of patients in the nationwide study, 373 cases were included in the detailed survey. Survey items included symptoms of AUB according to AUB system 1, examination details, and causative diseases according to the PALM-COEIN classification. RESULTS: Within the study period, we encountered 61 740 first-time patients, of which 8081 (13.1%) were diagnosed with AUB. Among them, 39.9% had abnormal menstrual cycles and 56.9% had abnormal menstrual bleeding. In the survey, PALM had the highest percentage of AUB-L and COEIN had the highest percentage of AUB-O. Correspondence analysis showed that COEIN was strongly associated with abnormal menstrual cycles and PALM with abnormal menstrual bleeding. CONCLUSION: We conducted the first nationwide survey of AUB in Japan. The FIGO classification was a useful tool for the diagnosis of AUB, with a strong correlation between symptoms of AUB by AUB system 1 and the causative disease of AUB by PALM-COEIN. Conversely, a high percentage of AUB-N and AUB-E suggests that AUB system 1 and PALM-COEIN are ambiguous as diagnostic tools.

Combined histological and DNA methylome profiling approaches may provide insights into the pathophysiology of ovarian endometriomas.

Purpose: To test the theory that invaginated ovarian surface epithelium and endometrial implants on the ovary form ovarian endometriomas. Methods: Adhesion sites of ovarian endometrioma on the peritoneum and consecutive ovarian endometrioma cyst wall, called non-adhesion sites, were histologically examined. DNA methylomes of the adhesion sites, non-adhesion sites, and blueberry spots were compared with those of ovary, endometrium, and peritoneum. Results: The non-adhesion sites showed an ovarian surface epithelium-like structure near the adhesion site, which continued to a columnar epithelium-like structure. Calretinin staining was strong in the ovarian surface epithelium-like structure but weak in the columnar epithelium-like structure. Estrogen receptors were absent in the ovarian surface epithelium-like structure, but present in the columnar epithelium-like structure. The adhesion sites had endometrial gland-like structures that expressed estrogen receptors. Analyses of DNA methylomes classified the non-adhesion sites and ovaries into the same group, suggesting that ovarian endometriomas originate from the ovarian surface epithelium. The adhesion sites, blueberry spots and peritoneum were classified in the same group, suggesting that the adhesion sites and blueberry spots originate from the peritoneum. Conclusions: The present results support the invagination theory. Ovarian endometriomas consist of invaginated ovarian surface epithelium with celomic metaplasia and endometrium implants on the peritoneum.

The essential glucose transporter GLUT1 is epigenetically upregulated by C/EBPß and WT1 during decidualization of the endometrium.

Human endometrial stromal cells (ESCs) differentiate into decidual cells by the action of progesterone, which is essential for implantation and maintenance of pregnancy. We previously reported that glucose uptake by human ESCs increases during decidualization and that glucose is indispensable for decidualization. Although glucose transporter 1 (GLUT1) is upregulated during decidualization, it remains unclear whether it is involved in glucose uptake. Here, we attempted to determine the role of GLUT1 during decidualization as well as the factors underlying its upregulation. ESCs were incubated with cAMP to induce decidualization. Knockdown of GLUT1 suppressed cAMP-increased glucose uptake and the expressions of specific markers of decidualization, IGF-binding protein-1 (IGFBP-1), and prolactin (PRL). To investigate the regulation of GLUT1 expression, we focused on CCAAT enhancer-binding protein ß (C/EBPß) and Wilms' tumor 1 (WT1) as the upstream transcription factors regulating GLUT1 expression. Knockdown of either C/EBPß or WT1 suppressed cAMP-increased GLUT1 expression and glucose uptake. cAMP treatment also increased the recruitment of C/EBPß and WT1 to the GLUT1 promoter region. Interestingly, cAMP increased the H3K27 acetylation (H3K27ac) and p300 recruitment in the GLUT1 promoter region. Knockdown of C/EBPß or WT1 inhibited these events, indicating that both C/EBPß and WT1 contribute to the increase of H3K27ac by recruiting p300 to the GLUT1 promoter region during decidualization. These findings indicate that GLUT1 is involved in glucose uptake in ESCs during decidualization, thus facilitating the establishment of pregnancy.

Fetal cardiac capillary hemangioma resulting in tachyarrhythmia.

We present the case of a fetus with cardiac capillary hemangioma in the right atrial cavity. The tumor showed dramatic growth between the 28th and 32nd week of gestation and resulted in tachyarrhythmia. The patient was born at the 33 weeks of gestation weighing 2430 g via urgent cesarean section because the rapidly growing cardiac tumor caused incessant tachyarrhythmia, pericardial effusion, and fetal circulatory incompetence. Coronary angiography revealed that the right coronary artery drained into the tumor. Due to hemodynamic deterioration, the patient underwent subtotal resection of the tumor on the 2nd day after birth. Histopathological examination revealed an undifferentiated capillary hemangioma. The patient was discharged at the age of 86 days, as the tachyarrhythmia and hemodynamic incompetence had subsided; however, bradycardia and intermittent atrioventricular conduction disturbance gradually developed. Capillary hemangioma, a rare primary cardiac space-occupying tumor in children, can invade the conduction system.

Wilms tumor 1 regulates lipid accumulation in human endometrial stromal cells during decidualization.

We previously reported that the transcription factor Wilms tumor 1 (WT1) regulates the expression of insulin-like growth factor-binding protein-1 (IGFBP-1) and prolactin (PRL) during decidualization of human endometrial stromal cells (ESCs). However, other roles of WT1 in decidualization remain to be fully clarified. Here, we investigated how WT1 regulates the physiological functions of human ESCs during decidualization. We incubated ESCs isolated from proliferative-phase endometrium with cAMP to induce decidualization, knocked down WT1 with siRNA, and generated three types of treatments (nontreated cells, cAMP-treated cells, and cAMP-treated + WT1-knockdown cells). To identify WT1-regulated genes, we used gene microarrays and compared the transcriptome data obtained among these three treatments. We observed that WT1 up-regulates 121 genes during decidualization, including several genes involved in lipid transport. The WT1 knockdown inhibited lipid accumulation (LA) in the cAMP-induced ESCs. To examine the mechanisms by which WT1 regulates LA, we focused on very low-density lipoprotein receptor (VLDLR), which is involved in lipoprotein uptake. We found that cAMP up-regulates VLDLR and that the WT1 knockdown inhibits it. Results of ChIP assays revealed that cAMP increases the recruitment of WT1 to the promoter region of the VLDLR gene, indicating that WT1 regulates VLDLR expression. Moreover, VLDLR knockdown inhibited cAMP-induced LA, and VLDLR overexpression reverted the suppression of LA caused by the WT1 knockdown. Taken together, our results indicate that WT1 enhances lipid storage by up-regulating VLDLR expression in human ESCs during decidualization.

Importance of Melatonin in Assisted Reproductive Technology and Ovarian Aging.

Melatonin is probably produced in all cells but is only secreted by the pineal gland. The pineal secretion of melatonin is determined by the light-dark cycle, and it is only released at night. Melatonin regulates biological rhythms via its receptors located in the suprachiasmatic nuclei of the hypothalamus. Melatonin also has strong antioxidant activities to scavenge free radicals such as reactive oxygen species (ROS). The direct free radical scavenging actions are receptor independent. ROS play an important role in reproductive function including in the ovulatory process. However, excessive ROS can also have an adverse effect on oocytes because of oxidative stress, thereby causing infertility. It is becoming clear that melatonin is located in the ovarian follicular fluid and in the oocytes themselves, which protects these cells from oxidative damage as well as having other beneficial actions in oocyte maturation, fertilization, and embryo development. Trials on humans have investigated the improvement of outcomes of assisted reproductive technology (ART), such as in vitro fertilization and embryo transfer (IVF-ET), by way of administering melatonin to patients suffering from infertility. In addition, clinical research has examined melatonin as an anti-aging molecule via its antioxidative actions, and its relationship with the aging diseases, e.g., Alzheimer's and Parkinson's disease, is also underway. Melatonin may also reduce ovarian aging, which is a major issue in assisted reproductive technology. This review explains the relationship between melatonin and human reproductive function, as well as the clinical applications expected to improve the outcomes of assisted reproductive technology such as IVF, while also discussing possibilities for melatonin in preventing ovarian aging.

The distal upstream region of insulin-like growth factor-binding protein-1 enhances its expression in endometrial stromal cells during decidualization.

We have previously shown that decidualization of human endometrial stromal cells (ESCs) causes a genome-wide increase in the levels of acetylation of histone-H3 Lys-27 (H3K27ac). We also reported that the distal gene regions, more than 3 kb up- or downstream of gene transcription start sites have increased H3K27ac levels. Insulin-like growth factor-binding protein-1 (IGFBP-1) is a specific decidualization marker and has increased H3K27ac levels in its distal upstream region (-4701 to -7501 bp). Here, using a luciferase reporter gene construct containing this IGFBP-1 upstream region, we tested the hypothesis that it is an IGFBP-1 enhancer. To induce decidualization, we incubated ESCs with cAMP and found that cAMP increased luciferase expression, indicating that decidualization increased the transcriptional activity from the IGFBP-1 upstream region. Furthermore, CRISPR/Cas9-mediated deletion of this region in HepG2 cells significantly reduced IGFBP-1 expression, confirming its role as an IGFBP-1 enhancer. A ChIP assay revealed that cAMP increased the recruitment of the transcriptional regulators CCAAT enhancer-binding protein ß (C/EBPß), forkhead box O1 (FOXO1), and p300 to the IGFBP-1 enhancer in ESCs. Of note, C/EBPß knockdown inhibited the stimulatory effects of cAMP on the levels of H3K27ac, chromatin opening, and p300 recruitment at the IGFBP-1 enhancer. These results indicate that the region -4701 to -7501 bp upstream of IGFBP-1 functions as an enhancer for IGFBP-1 expression in ESCs undergoing decidualization, that C/EBPß and FOXO1 bind to the enhancer region to up-regulate IGFBP-1 expression, and that C/EBPß induces H3K27ac by recruiting p300 to the IGFBP-1 enhancer.

Genome-wide DNA methylation analysis revealed stable DNA methylation status during decidualization in human endometrial stromal cells.

BACKGROUND: During decidualization in endometrial stromal cells (ESCs), expressions of a number of genes and epigenetic modifications of histones are altered. However, there is little information about whether DNA methylation, which is another epigenetic mechanism, also changes during decidualization. Here, we examined the genome-wide DNA methylation profiles in ESCs during decidualization and their associations with the changes of gene expressions and histone modifications. RESULTS: ESCs were incubated with estradiol and medroxyprogesterone acetate for 14 days to induce decidualization. The genome-wide DNA methylation profiles were compared between the non-decidualized ESCs and the decidualized ESCs. Of 482,005 CpGs, only 23 CpGs (0.0048%) showed different DNA methylation statuses. The DNA methylation statuses of the differentially expressed genes and the regions with different histone modifications (H3K4 tri-methylation and H3K27 acetylation) were also compared between the ESCs. In the upregulated and downregulated genes in decidualized ESCs, DNA methylation statuses around the promoter region of the genes did not significantly differ between the ESCs. In the regions with different histone modification, DNA methylation statuses did not differ between the ESCs. The differentially expressed genes and the differential histone modification regions were hypomethylated. CONCLUSIONS: Culturing ESCs with estrogen/progesterone did not distort the physiological pattern of DNA methylation, although mRNA expression and histone modifications were dynamically altered. A genome-wide DNA methylation analysis revealed stable DNA methylation statuses during decidualization in human endometrial stromal cells. DNA hypomethylation is maintained for the variable changes of histone modifications and gene expression during decidualization.

Glucose regulates the histone acetylation of gene promoters in decidualizing stromal cells.

Decidualization stimuli activate the insulin signaling pathway and increase the glucose uptake in human endometrial stromal cells (ESCs). The inductions of prolactin (PRL) and IGF-binding protein-1 (IGFBP1), specific markers of decidualization, were inhibited by incubating ESCs under low glucose concentrations. These results suggested that decidualization stimuli activate the insulin signaling pathway, which contributes to decidualization through the increase of glucose uptake. Here, we investigated the mechanisms by which glucose regulates decidualization. ESCs were incubated with cAMP to induce decidualization. We examined whether low glucose affects the expression levels of transcription factors that induce decidualization. Forkhead box O1 (FOXO1) expression was significantly suppressed under low glucose conditions. Knockdown of FOXO1 by siRNA inhibited the expression levels of PRL and IGFBP1 during decidualization. Taken together, our results showed that low glucose inhibits decidualization by decreasing FOXO1 expression. We also examined the levels of histone H3K27 acetylation (H3K27ac), which is related to active transcription, of the promoter regions of FOXO1, PRL and IGFBP1 by ChIP assay. The H3K27ac levels of these promoter regions were increased by decidualization under normal glucose conditions, but not under low glucose conditions. Thus, our results show that glucose is indispensable for decidualization by activating the histone modification status of the promoters of PRL, IGFBP1 and FOXO1.

SATB2 and NGR1: potential upstream regulatory factors in uterine leiomyomas.

PURPOSE: We attempted to identify the genes involved in the pathogenesis of uterine leiomyomas, under a hypothesis that the aberrant expression of upstream regulatory genes caused by aberrant DNA methylation is involved in the onset and development of uterine leiomyomas. METHODS: To find such genes, we compared genome-wide mRNA expression and DNA methylation in uterine leiomyomas and adjacent normal myometrium. Analysis of the data by Ingenuity Pathway Analysis software identified SATB2 which is known to be an epigenetic regulator, and NRG1 as candidate upstream regulatory genes. To infer the functions of these genes, human uterine smooth muscle cell lines overexpressing SATB2 or NRG1 genes were established (SATB2 or NRG1 lines), and their transcriptomes and pathways were analyzed. RESULTS: SATB2 and NRG1 were confirmed to be hypermethylated and upregulated in most uterine leiomyoma specimens (nine to 11 of the 11 cases). Among the established cell lines, morphological changes from spindle-like forms to fibroblast-like forms with elongated protrusions were observed in only the SATB2 line. Pathway analysis revealed that WNT/ß-catenin and TGF-ß signaling pathways which are related to the pathogenesis of uterine leiomyomas were activated in both SATB2 and NRG1 lines. In addition, signaling of growth factors including VEGF, PDGF, and IGF1, and retinoic acid signaling were activated in the SATB2 and NRG1 lines, respectively. CONCLUSIONS: These results indicate that SATB2 and NRG1 overexpression induced many of the signaling pathways that are considered to be involved in the pathogenesis of uterine leiomyomas, suggesting that these genes have roles as upstream regulatory factors.

SMITE: an R/Bioconductor package that identifies network modules by integrating genomic and epigenomic information.

BACKGROUND: The molecular assays that test gene expression, transcriptional, and epigenetic regulation are increasingly diverse and numerous. The information generated by each type of assay individually gives an insight into the state of the cells tested. What should be possible is to add the information derived from separate, complementary assays to gain higher-confidence insights into cellular states. At present, the analysis of multi-dimensional, massive genome-wide data requires an initial pruning step to create manageable subsets of observations that are then used for integration, which decreases the sizes of the intersecting data sets and the potential for biological insights. Our Significance-based Modules Integrating the Transcriptome and Epigenome (SMITE) approach was developed to integrate transcriptional and epigenetic regulatory data without a loss of resolution. RESULTS: SMITE combines p-values by accounting for the correlation between non-independent values within data sets, allowing genes and gene modules in an interaction network to be assigned significance values. The contribution of each type of genomic data can be weighted, permitting integration of individually under-powered data sets, increasing the overall ability to detect effects within modules of genes. We apply SMITE to a complex genomic data set including the epigenomic and transcriptomic effects of Toxoplasma gondii infection on human host cells and demonstrate that SMITE is able to identify novel subnetworks of dysregulated genes. Additionally, we show that SMITE outperforms Functional Epigenetic Modules (FEM), the current paradigm of using the spin-glass algorithm to integrate gene expression and epigenetic data. CONCLUSIONS: SMITE represents a flexible, scalable tool that allows integration of transcriptional and epigenetic regulatory data from genome-wide assays to boost confidence in finding gene modules reflecting altered cellular states.

Long-term melatonin treatment delays ovarian aging.

Ovarian aging is characterized by gradual declines in oocyte quantity and quality. Melatonin is considered an anti-aging agent due to its cytoprotective actions as an antioxidant. This study examined whether long-term melatonin treatment would delay ovarian aging in mice. Female ICR mice (10 weeks old) were given melatonin-containing water (100 µg/mL; melatonin) or water only until 43 weeks of age. Their oocytes were recovered from the oviduct, and in vitro fertilization was performed. The ovaries were used for a histological analysis of the number of follicles. The mRNA expression of the aging-related sirtuin genes (SIRT1, SIRT3) and the autophagy-related gene (LC3) and the telomere length of the ovarian chromosomes were analyzed. Transcriptome changes in the ovaries were also characterized using microarray. The number of ovulated oocytes decreased with age; however, it was greater in melatonin-treated mice than that from control animals. The decreased fertilization rate and blastocyst rate during aging also were higher in the melatonin-treated mice than in the controls, as were the numbers of primordial, primary, and antral follicles. The mRNA expression of SIRT1 and LC3 and telomere length were enhanced due to melatonin treatment. Seventy-eight genes that were downregulated during aging and upregulated by melatonin were identified by a microarray analysis. Forty of these 78 genes were ribosome-related genes, and a free radical scavenging network was identified. The present results indicate that melatonin delays ovarian aging by multiple mechanisms including antioxidant action, maintaining telomeres, stimulating SIRT expression and ribosome function, and by reducing autophagy.

Thin endometrium transcriptome analysis reveals a potential mechanism of implantation failure.

Aim: Although a thin endometrium has been well recognized as a critical factor in implantation failure, little information is available regarding the molecular mechanisms. The present study investigated these mechanisms by using genome-wide mRNA expression analysis. Methods: Thin and normal endometrial tissue was obtained from a total of six women during the mid-luteal phase of the menstrual cycle. The transcriptomes were analyzed with a microarray. Differentially expressed genes were classified according to Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Results: The study identified 318 up-regulated genes and 322 down-regulated genes in the thin endometrium, compared to the control endometrium. The GO and KEGG pathway analyses indicated that the thin endometrium possessed aberrantly activated immunity and natural killer cell cytotoxicity that was accompanied by an increased number of inflammatory cytokines, such as IFN-γ. Various genes that were related to metabolism and anti-oxidative stress were down-regulated in the thin endometrium. Conclusion: Implantation failure in the thin endometrium appears to be associated with an aberrantly activated inflammatory environment and aberrantly decreased response to oxidative stress.