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Purpose: To screen novel mutations in LHCGR responsible for empty follicle syndrome and explore the pathological mechanism of mutations., Methods: Four affected individuals diagnosed with infertility-associated anovulation or oligo-ovulation from three independent families were recruited. Sanger sequencing was used to identify the LHCGR mutations in affected individuals. Western blot was performed to evaluate the effects of mutations on LHCGR protein levels. Immunofluorescence was done to explore the effects of mutations on LHCGR subcellular localization. The ATP levels were measured to infer the functional effects of the mutations on LHCGR., Results: In the present study, three novel biallelic mutations in LHCGR were identified in four affected individuals from three independent families with empty follicle syndrome or oligo-ovulation. All biallelic mutations were inherited from the proband of their parents. The western blot showed that the identified mutations decreased LHCGR protein level and altered the glycosylation pattern. The immunofluorescence showed an ectopic subcellular localization of LHCGR in cultured HeLa cells. Besides, the mutations in LHCGR also reduced the cellular ATP consumption., Conclusion: These findings confirm previous studies and expand the mutational spectrum of LHCGR, which will provide genetic diagnostic marker for patients with empty follicle syndrome.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases with an uncertain pathology and the most frequent incretory disorder in women of reproductive age, often leading to female infertility. Evidence has shown that genetic factors may contribute to the etiology of PCOS. Contradictory results have been reported concerning the association between PCOS and the CYP11A1 gene promoter -528 bp pentanucleotide (tttta)n repeat polymorphism. In order to get an overall understanding of the association between the CYP11A1 gene promoter -528 bp pentanucleotide (tttta)n repeat polymorphism and PCOS, case-control studies regarding this association were extracted from MEDLINE, Ovid EMBASE and PubMed and pooled for meta-analysis. In dichotomous allelic analyses with 1,236 PCOS patients and 1,306 control subjects, the odds ratios (ORs) were very close to 1. In dichotomous genotypic analyses with 1,063 PCOS patients and 1,176 control subjects, the (tttta)4 genotype may increase the risk of PCOS in a recessive model with OR 1.44, 95% confidence interval (CI) 1.12-1.85, and the (tttta)6 genotype may decrease the risk of PCOS in a dominant model with OR 0.76, 95% CI 0.61-0.93. In continuous analyses with 1,085 PCOS patients and 1,216 control subjects, the Mean Difference (MD) was -0.07 with a 95% CI -0.18 to 0.05, showing no difference between PCOS and control groups. No publication bias was found in either dichotomous or continuous analyses. Taken together, there may be an association between CYP11A1 promoter pentanucleotide repeat polymorphism and PCOS. Further research is needed to strictly confirm our findings.

Steroid synthesis and metabolic pathways play important roles in the pathophysiology of PCOS, but until now there have been no studies on the methylation profiles of specific genes in steroid synthesis pathways that are known to be associated with PCOS. Here we used MassARRAY quantitative methylation analysis to determine the methylation levels of each CpG site or cluster in the promoters of EPHX1, SRD5A1, and CYP11A1 in 64 peripheral blood samples. We further examined the methylation level of EPHX1 in an independent cohort consisting of 116 people. Finally, we investigated the role of EPHX1 in steroidogenesis in the KGN cell line. For SRD5A1 and CYP11A1, there was no significant difference in methylation level between patients and controls. For EPHX1, however, the methylation levels of a few consecutive CpG sites and clusters were found to be significantly associated with PCOS. The methylation levels of a number of CpG clusters or sites were significantly lower in patients than in controls in the first cohort consisting of 64 people, such as clusters 13-14 (P<0.05), 15-16 (P<0.001), and 19-24 (P<0.001) and sites CpG&#95;53 (P<0.01) and CpG&#95;54 (P<0.05). Among differentiated methylation sites and clusters, the methylation levels of the CpG cluster 13-14 and CpG cluster 19-24 in PCOS patients were significantly lower than in controls in the second cohort of 116 people (P<0.05 for both). In addition, knockdown and overexpression experiments in KGN cells showed that EPHX1 can regulate estradiol concentrations, and this indicates a role for EPHX1 in steroidogenesis. Our study has demonstrated that methylation of the EPHX1 promoter might be associated with PCOS. This study provides direct evidence that methylation plays an important role in PCOS and demonstrates a novel role for EPHX1 in female reproduction.

Context: Telomeres are specialized chromatin structures located at the ends of eukaryotic chromosomes, and telomere length plays a clear role in various diseases. However, it is not known whether telomere length is related to polycystic ovary syndrome (PCOS)., Objective: We hypothesized that leukocyte telomere length (LTL) plays an important role in the pathophysiology of PCOS., Design: We used an established and validated quantitative PCR technique to measure the mean LTL in a large sample of PCOS patients and controls. We used logistic regression and multiple linear regression to analyze the association of PCOS and several related clinical parameters with the age-adjusted ratio of the telomere repeat length to the copy number of a single-copy gene (T/S)., Results: Individuals with PCOS (n = 698) exhibited significantly shorter LTLs than the controls (n = 611) after adjusting for age (0.764 ± 0.016 vs 0.876 ± 0.023; P = .001; odds ratio = 1.403; 95% confidence interval, 1.150-1.712). The mean telomere length in the leukocytes of PCOS patients was comparable to that of control individuals who were on average 6.16 years older. Individuals having shorter telomere lengths (middle and lowest tertile) had significantly higher disease risk than those having the longest telomere length (highest tertile) (odds ratio = 1.614; 95% confidence interval, 1.262-2.066; P = .0001) after adjusting for age. In addition, a significant correlation between the LTL and the level of dehydroepiandrosterone sulfate was observed in controls (r = -0.185; P = .01)., Conclusion: We provide the first report that LTL is strongly associated with PCOS. This study suggests a new role for LTL in the pathophysiology of PCOS and might have important implications for our understanding of the etiology of the disease.

Context: Human follicular fluid is a combination of proteins, metabolites, and ionic compounds that is indicative of the general state of follicular metabolism and is associated with maturation and quality of oocytes. Deviations in these components are often associated with reproductive diseases. There has been no report of microRNAs (miRNAs) in human follicular fluids., Objective: We hypothesized that human follicular fluid may contain miRNAs. We sought to identify cell-free miRNAs in human follicular fluid and to investigate the function of these miRNAs in vitro and any roles they play in polycystic ovary syndrome (PCOS)., Design: Genome-wide deep sequencing and TaqMan miRNA arrays were used to identify miRNAs, and the roles of the highly expressed miRNAs in steroidogenesis were investigated in KGN cells. Quantification of candidate miRNAs in follicular fluids of PCOS and controls was performed using TaqMan miRNA assays., Results: We identified miRNAs in microvesicles and the supernatant of human follicular fluid. Bioinformatics analysis showed that the most highly expressed miRNAs targeted genes associated with reproductive, endocrine, and metabolic processes. We found that miR-132, miR-320, miR-520c-3p, miR-24, and miR-222 regulate estradiol concentrations and that miR-24, miR-193b, and miR-483-5p regulate progesterone concentrations. Finally, we showed that miR-132 and miR-320 are expressed at significantly lower levels in the follicular fluid of polycystic ovary patients than in healthy controls (P = .005 and P = .0098, respectively)., Conclusion: These results demonstrate that there are numerous miRNAs in human follicular fluids, some of which play important roles in steroidogenesis and PCOS. This study substantially revises our understanding of the content of human follicular fluid and lays the foundation for the future investigation of the role of miRNAs in PCOS.

CYP1B1 encodes an estrogen enzyme that oxidizes 17β-estradiol to 4-hydroxyestradiol. The evidence demonstrates there may be a relationship between CYP1B1 and thyroid function. To date, no study has evaluated if genetic polymorphisms that regulate concentrations of serum FT3 and FT4 contribute to Polycyctic Ovary Syndrome (PCOS). To identify polymorphisms in the CYP1B1 locus associated with PCOS, we genotyped three common polymorphisms across the CYP1B1 locus in 226 patients. A test for association of common variants with susceptibility to PCOS was conducted in a large cohort of 609 subjects. The functional polymorphism CYP1B1 L432V (rs1056836) is associated with serum T4 (P = 0.003), serum FT3 (P < 0.001) and serum FT4 concentrations (P < 0.001). Our study provides the first evidence that genetic variants in CYP1B1 can be associated with serum T4, FT4 and FT3 levels in PCOS. These findings imply novel pathophysiological links between the CYP1B1 locus and thyroid function in PCOS.

Epigenetic mechanisms may contribute to polycystic ovary syndrome (PCOS). To date, however, no studies have associated CpG methylation levels of any candidate gene with PCOS susceptibility. Follistatin (FST), an activin-binding protein, is expressed in numerous tissues and is shown to have linkage with PCOS. However, results from case-control association analyses between this gene and PCOS are inconsistent. Thus, this study investigated possible association of methylation levels in the promoter and 5'-untranscribed region (UTR) of the FST gene with PCOS incidence in peripheral blood leukocytes and endometrial tissue. Using mass array quantitative methylation analysis, first the 5'-UTR methylation in FST was analysed in 130 PCOS patients and 120 controls. The methylation level of the FST gene was further studied in endometrium from 24 controls and 24 PCOS patients. This study demonstrates that methylation levels of CpG sites in the FST promoter and 5'-UTR are not associated with PCOS. Nonetheless, this was the first study to quantitatively evaluate the methylation levels of a candidate gene in association with PCOS. Further studies should be performed to examine methylation in other candidate genes. Understanding the epigenetic mechanisms involved in PCOS may yield new insights into the pathophysiology of the disorder. Animal models demonstrate that epigenetic reprogramming may contribute to polycystic ovary syndrome (PCOS). To date, however, no studies have associated CpG methylation levels of any candidate gene with PCOS susceptibility. Follistatin (FST), an activin-binding protein, is expressed in numerous tissues and is a PCOS candidate gene. However, results from association analyses between this gene and PCOS are inconsistent. Thus, we investigated possible association of methylation levels in the promoter and 5'-UTR of the FST gene with PCOS incidence in peripheral blood leukocytes and endometrial tissue. Using mass array quantitative methylation analysis, we firstly analysed 5'-UTR methylation in 40 PCOS patients and 40 controls. We then validated results in a second sample consisting of 90 PCOS patients and 80 controls. The methylation level of the FST gene was further studied in endometrium from 24 controls and 24 PCOS patients. Finally, we quantitatively analysed FST expression in the endometrium using real-time PCR. Our study demonstrated that methylation levels of CpG sites in the FST promoter and 5'-UTR are not associated with PCOS. Nonetheless, as far as is known, this is the first study to quantitatively evaluate the methylation levels of a candidate gene in association with PCOS. Further studies should be performed to examine methylation in other candidate genes. Understanding the epigenetic mechanisms involved in PCOS may yield new insights into the pathophysiology of the disorder., (Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

Aromatase is a key enzyme involved in estradiol and estrone biosynthesis. Given that polymorphisms of the CYP19A1 gene encoding aromatase have been correlated with plasma testosterone levels, CYP19A1 may therefore act as a genetic modifier of the hyperandrogenic phenotype of polycystic ovary syndrome (PCOS). However, no functional CYP19A1 polymorphisms that predict the risk of PCOS have been identified. We explored the role of CYP19A1 genetic variation in a large case-control study involving 1078 samples, in which five common genetic polymorphisms were scored. Human embryonic kidney 293 cells were transiently transfected with a vector encoding either the CYP19A1 wild-type (WT) allele or an Arg(264)Cys variant to evaluate aromatase activity. Cells were cultured with androstenedione and estrone levels were measured using a specific ELISA. The Arg(264)Cys variant of CYP19A1 (rs700519) is associated with PCOS (P= 0.004, corrected P = 0.02). In this functional study, when cells were cultured in varying concentrations of androstenedione (100, 400 and 500 nM), transfection with the Arg(264)Cys variant resulted in increased conversion of androstenedione to estrogen when compared with transfection with the WT construct (P< 0.001). Our data suggest that the common missense polymorphism rs710059 is associated with susceptibility to PCOS and that the Arg(264)Cys variant may increase aromatase enzymatic activity. Overall, these findings imply that aromatase plays an important role in PCOS.

Gonadotropin-releasing hormone receptor (GNRHR) is a member of the G protein-coupled Ca(2+)-dependent family of receptors. It interacts with GnRH, whose signaling plays an important role in thyroid-stimulating hormone (TSH) secretion and insulin activity. There has been no study on the genetic effect of GNRHR on TSH secretion and insulin action in polycystic ovary syndrome (PCOS). We decided to investigate whether naturally occurring genetic variation at the human GNRHR locus is associated with thyroid function, insulin secretion and insulin sensitivity in PCOS. We undertook a systematic search for polymorphisms in GNRHR by resequencing the gene and then genotyped common single-nucleotide polymorphisms across the locus in 261 PCOS patients well-phenotyped for several metabolic traits to determine associations. A test for association of common genetic variants with susceptibility to PCOS was carried out in a large cohort of 948 subjects. Finally, we experimentally validated the marker-on-trait associations using GNRHR 3'-UTR region/reporter analysis in 293T cells. The 3'-UTR variant rs1038426 was associated with serum thyroid concentration (P = 0.007), change of insulin levels during oral glucose tolerance test (P = 0.004) and insulin sensitivity index (P = 0.014). In a functional study, 3'-UTR variant T allele increased reporter expression by a transfected luciferase reporter/GNRHR 3'-UTR expression plasmid. In conclusion, our results strongly suggest that common genetic variant in GNRHR contributes to the phenotypic expression of PCOS. The findings suggest novel pathophysiological links between the GNRHR locus and thyroid function and insulin secretion in PCOS.