Do long non-coding RNA (lncRNA) and messenger RNA (mRNA) profiles in follicular fluid from mature and immature ovarian follicles differ between healthy women and women with polycystic ovary syndrome (PCOS)? lncRNA and mRNA profiles in follicular fluid from both mature and immature ovarian follicles differed significantly between healthy women and PCOS patients. Unlike microRNAs, which have been extensively studied, lncRNAs present in follicular fluid have never been sequenced and the biological associations of lncRNAs in healthy follicles and follicles in women who develop PCOS remain largely unknown. A total of 18 subjects (8 controls and 10 PCOS patients) were recruited to participate in this study. Recruitment took place from May 2016 to September 2016. The follicular fluid donors underwent their first round of in-vitro fertilization treatment. Follicle size was determined based on the average follicular diameter, and follicular fluid samples were collected from mature follicles (17–22 mm) and matched-immature follicles (8–13 mm). RNA sequencing was performed on follicular fluids from mature and immature follicles of healthy women and PCOS patients. A total of 1583 novel lncRNAs were identified in 36 human follicular fluid samples and some were expressed differently in healthy and PCOS women. lncRNAs associated with the metabolic process were highly enriched in the follicular fluid of mature follicles from the PCOS group versus the healthy group. In the PCOS group, nervous system process lncRNAs were highly enriched in the follicular fluid of mature versus immature follicles, whereas in the healthy group, lncRNAs associated with junction adhesion and communication-related processes were highly enriched in the follicular fluid of mature versus immature follicles. In addition, differentially expressed mRNAs were principally linked to olfactory transduction pathways. Consistent results from Gene Set Enrichment Analysis (GSEA) and Gene Ontology (GO) indicated that telomere maintenance and MAPK and Wnt pathways may be conserved processes, active in follicular development, and monosaccharide biosynthesis might provide possible pathway markers to distinguish between normal and PCOS follicles. We constructed gene co-expression networks that identified many co-regulatory relationships among follicular fluid lncRNAs, mRNAs, and PCOS phenotypes. Weighted Gene Co-expression Network Analysis (WGCNA) revealed lncRNAs and mRNAs that were core and others associated with the PCOS phenotype. It remains unclear whether these differential transcripts contribute directly to follicular development or the pathogenesis of PCOS, or are merely biomarkers. It will be important in the future for investigators to ascertain the biologic mechanisms underlying the development of both normal and PCOS follicles. This work was supported by the National Natural Science Foundation of China (No. 81671423, No. 81402130 and No. 81501247), the Fok Ying Tung Education Foundation (No. 151039), and Distinguished Talent Program of Shengjing Hospital (No. ME76). No competing interests declared.

Background: Leptin may have important implications in polycystic ovary syndrome (PCOS)-related metabolic disorders. However, the changes in serum leptin levels in patients with PCOS and its predictive value for PCOS remain obscure. We intend to analyze the association between leptin and PCOS in this study.Materials and Methods: The study comprised 89 patients with PCOS and 139 individuals without PCOS. Each group was stratified as either normal- or hyper-fasting serum insulin (FSI), and lean or overweight/obese; and the patients were further categorized as normal- or hyper-androgenic. The validity of leptin toward the diagnosis of PCOS, or leptin combined with total testosterone, dehydroepiandrosterone sulfate (DHEAS), and free testosterone was estimated by receiver operating characteristic (ROC) curves, and correlations between paired variables was estimated by Spearman’s rank correlation coefficient. Associations between the clinical and metabolic variables and PCOS were analyzed via logistic regression.Results: The serum leptin levels of patients with PCOS were significantly higher than that of the control, and especially the PCOS in hyper-FSI, hyperandrogenimic and overweight/obese subgroups. The area under the ROC curve (AUC) of leptin was 74%, with cutoff value, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) 11.58 ng/mL, 77.5%, 62.6%, 57.0%, and 81.3%, respectively. Combined leptin and anti-Müllerian hormone (AMH) had the highest AUC (92.3%), excellent sensitivity (93.3%), moderate specificity (78.3%), PPV (73.5%) and NPV (94.8%). Serum leptin levels of the patients were correlated with the FSI, fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI), and total testosterone levels. Elevated serum leptin was associated with a high risk of PCOS [P = 0.015; OR (95% CI) 1.128 (1.024–1.244)].Conclusion: Substantially elevated serum leptin is significantly associated with PCOS. These findings warrant further investigations into the function of leptin in the pathogenesis of PCOS.

Semen samples from men after a short ejaculatory abstinence show improved sperm quality and result in increased pregnancy rates, but the underlying mechanisms remain unclear. Herein, we report that ejaculates from short (1–3 hours) compared with long (3–7 days) periods of abstinence showed increases in motile sperm count, sperm vitality, normal sperm morphology, acrosome reaction capacity, total antioxidant capacity, sperm mitochondrial membrane potential, high DNA stainability, and a decrease in the sperm DNA fragmentation index (P < 0.05). Sperm proteomic analysis showed 322 differentially expressed proteins (minimal fold change of ±1.5 or greater and P < 0.05), with 224 up-regulated and 98 down-regulated. These differentially expressed proteins are profoundly involved in specific cellular processes, such as motility and capacitation, oxidative stress, and metabolism. Interestingly, protein trimethyllysine modification was increased, and butyryllysine, propionyllysine, and malonyllysine modifications were decreased in ejaculates from a short versus long abstinence (P < 0.05). Finally, the rates of implantation, clinical pregnancy, and live births from in vitro fertilization treatments were significantly increased in semen samples after a short abstinence. Our study provides preliminary mechanistic insights into improved sperm quality and pregnancy outcomes associated with spermatozoa retrieved after a short ejaculatory abstinence.

Irregular menstruation is clinically associated with an increased risk for ovarian cancer and disease-related mortality. This relationship remains poorly understood, and a mechanism explaining it has yet to be described. Ovarian tissues from women with polycystic ovary syndrome (PCOS) and regular menstruation (n = 10) or irregular menstruation (n = 10) were subjected to DNA methylation sequencing, real-time PCR array, whole-exome sequencing, and bioinformatics analysis. We demonstrated that ovarian tissue from PCOS patients with irregular menstruation displayed global DNA hypomethylation, as well as hypomethylation at several functionally and oncologically significant regions. Furthermore, we showed that several cancer-related genes were aberrantly expressed in ovarian tissue from patients with irregular menstruation, and that their mRNA and microRNA profiles shared appreciable levels of coincidence with those from ovarian cancer tissue. We identified multiple point mutations in both the BRCA1 and MLH1 genes in patients with irregular menstruation, and predicted the potential pathogenicity of these mutations using bioinformatics analyses. Due to the nature of ovarian cancer, it is important to broaden our understanding of the pathogenesis and risk factors of the disease. Herein, we provide the first description of a genetic and epigenetic basis for the clinical relationship between irregular menstruation and an increased risk for ovarian cancer.

Significance: A clear mechanistic understanding of metformin’s antidiabetic effects is lacking. This is because suprapharmacological concentrations of metformin have been used in most studies. Using mouse models and human primary hepatocytes, we show that metformin, at clinically relevant doses, suppresses hepatic glucose production by activating a conserved regulatory pathway encompassing let-7, TET3, and a fetal isoform of hepatocyte nuclear factor 4 alpha (HNF4α). We demonstrate that metformin no longer has potent antidiabetic actions in a liver-specific let-7 loss-of-function mouse model and that hepatic delivery of let-7 ameliorates hyperglycemia and improves glucose homeostasis. Our results thus reveal an important role of the hepatic let-7/TET3/HNF4α axis in mediating the therapeutic effects of metformin and suggest that targeting this axis may be a potential therapeutic for diabetes.