The polymorphism (-600 C>A) of CpG methylation site at the promoter region of CYP17A1 and its association of male infertility and testosterone levels

Sea cucumber peptides positively regulate sexual hormones in male mice with acute exhaustive swimming: possibly through the Ca2+/PKA signaling pathway

Sea cucumber peptides (SCPs) have been proven to have many active functions; however, their impact on testosterone synthesis and the corresponding mechanism are not yet clear. This study attempts to explore the effects of SCPs on sex hormone regulation in acute exhaustive swimming (AES) male mice and the possible mechanisms. In the present study, SCP intervention significantly prolonged exhaustive swimming time and reduced exercise metabolite accumulation. The reproductive ability-related parameters including penile index, mating ability, testicular morphology, and sperm storage were dramatically improved by SCP intervention. Notably, SCPs markedly reversed the AES-induced decrease in serum testosterone (T), estradiol (E2), and follicle-stimulating hormone (FSH) levels. Moreover, treatment with a high dose of SCP (0.6 mg per g bw) significantly enhanced the expression of testosterone synthesis-related proteins in testis, meanwhile markedly increasing the gene expression of StAR, Hsd17b3, Hsd17b2, Ldlr, and Cyp19a1. Serum metabolomics results indicated that SCP intervention notably upregulated the expression of 1-stearoyl-2-arachidonoyl-sn-glycerol but downregulated the concentrations of succinate and DL-lactate. Furthermore, serum metabolomics combined with testicular transcriptome, western blot, and correlation analyses demonstrated that SCPs may regulate testosterone synthesis via the Ca2+/PKA signaling pathway. This study indicated that the SCP could be a potential dietary supplement to improve the symptoms of decreased sex hormones related to exercise fatigue.

Multiomics analysis of male infertility

Infertility affects 8-12% of couples globally, and the male factor is a primary cause in approximately 50% of couples. Male infertility is a multifactorial reproductive disorder, which can be caused by paracrine and autocrine factors, hormones, genes, and epigenetic changes. Recent studies in rodents and most notably in humans using multiomics approach have yielded important insights into understanding the biology of spermatogenesis. Nonetheless, the etiology and pathogenesis of male infertility are still largely unknown. In this review, we summarized and critically evaluated findings based on the use of advanced technologies to compare normal and obstructive azoospermia (OA) versus non-obstructive azoospermia (NOA) men, including whole-genome bisulfite sequencing (WGBS), single cell RNA-seq (scRNA-seq), whole exome sequencing (WES), and ATAC-seq. It is obvious that the multiomics approach is the method of choice for basic research and clinical studies including clinical diagnosis of male infertility.

Zuogui Wan improves spermatogenesis of GC1-spg cells through modulating AR-related pathways

Zuogui Wan (ZGW) is a common prescription medication used in traditional Chinese medicine (TCM) to significantly improve the sperm quality and treat male infertility. This study evaluated the repair effect of ZGW and Levocarnitine (LEV) on GC1-spg cell injury induced by Glucosides of Tripterygium WilforDII Hook (GTW). The results showed that the ultrastructure and apoptosis rate of GC1- spg cells in LEV and ZGW group were considerably better than GTW. The transcriptional and translational level of CYP1A1, CYP17A1, androgen receptor (AR), SRD5A2 and proliferating cell nuclear antigen (PCNA) in GC-1spg cells of the LEV group were considerably elevated than GTW group (p < 0.05 or 0.01). Furthermore, the transcriptional and translational levels of CYP19A1, CYP17A1, AR, SRD5A2 and PCNA in GC-1spg cells in ZGW group were found to be considerably elevated than the LEV group (p < 0.05 or 0.01). The findings indicate that ZGW and LEV could increase the expression of PCNA, CYP17A1, CYP19A1, SRD5A2 and AR at transcriptional and translational levels, inhibit GC-1spg cell apoptosis and promoting cell proliferation, and the effect of ZGW was found to be significantly better than that of LEV.

Associations Between Cytochrome P450 (CYP) Gene Single-Nucleotide Polymorphisms and Second-to-Fourth Digit Ratio in Chinese University Students

BACKGROUND Cytochrome P450 (CYP) genes are necessary for the production or metabolism of fetal sex hormones during pregnancy. The second-to-fourth digit ratio (2D: 4D) is formed in the early stage of human fetal development and considered an indicator reflecting prenatal sex steroids levels. We explored the association between 2D: 4D and single-nucleotide polymorphisms (SNPs) of CYP. MATERIAL AND METHODS Correlation analysis between 2D: 4D and 8 SNPs, rs2687133 (CPY3A7), rs7173655 (CYP11A1), rs1004467, rs17115149, and rs2486758 (CYP17A1), and rs4646, rs2255192, rs4275794 (CYP19A1), was performed using data from 426 female and 412 male Chinese university students. SNP genotyping was conducted using PCR. Digit lengths were photographed and measured by image processing software. RESULTS rs2486758 (CYP17A1) correlated with left hand 2D: 4D in men (P=0.026), and rs1004467 (CYP17A1) correlated with right hand 2D: 4D in men (P=0.008) and the whole population (P=0.032). In men, allele G rs1004467 decreased right hand 2D: 4D, while allele C of rs2486758 increased left hand 2D: 4D. In women, left hand 2D: 4D was higher in genotypes with allele A of SNP rs4646 (CYP19A1) under the dominant genetic model; female DR-L was higher in genotypes with allele T of rs17115149 (CYP11A1). SNPs rs2687133 (CYP3A7) and rs1004467 (CYP17A1) were significantly correlated with right hand 2D: 4D (P=0.0107). CONCLUSIONS SNPs rs1004467 and rs2486758 of CYP17A1 are significant in the relationship between 2D: 4D and CYP gene polymorphisms under different conditions. SNP interactions between CYP genes probably impact 2D: 4D. The correlation between 2D: 4D and some sex hormone-related diseases may be due to the effect of CYP variants on the 2 phenotypes.

Altered expression of CYP17A1 and CYP19A1 in undescended testes of dogs with unilateral cryptorchidism

Cryptorchidism is the most common disorder of sex development in dogs and testosterone plays a crucial role in the inguinal phase of the testes descending into the scrotum. The molecular background of impaired testosterone synthesis in the testes of cryptorchid dogs is poorly elucidated. In this study, we analyzed the expression of four genes involved in testicular steroidogenesis (CYP17A1, CYP19A1, HSD3B2 and HSD17B3) in undescended and contralateral scrotal testes from inguinal unilateral cryptorchid dogs (n = 13) and from the scrotal gonads of normal males (n = 15). We found that transcript level of CYP17A1 was significantly increased in inguinal gonads, while the level of CYP19A1 was decreased. For these two genes, we analyzed the methylation level of single CpG sites in the promoter region localized within putative target sites for testicular transcription factors (NUR77, CREB, CAR and HSF2). A correlation between decreased methylation in the promoter of CYP17A1 and its increased transcript level in undescended gonads was observed, but the change in protein level was not significant. We also resequenced the 5'-flanking region of both genes and two known polymorphic sites, SNP in CYP17A1 and an indel in CYP19A1, were found. However, the distribution of the variants in affected (n = 80) and control (n = 75) dogs was not associated with cryptorchidism. We tentatively conclude that the altered expression of CYP17A1 and CYP19A1 in undescended testes could be caused by their exposure to increased temperature in the body. Furthermore, we showed that the identified polymorphisms cannot be considered markers associated with a predisposition to cryptorchidism.

A Study on the Association Between Polymorphisms in the Cytochrome P450 Family 17 Subfamily A Member 1 Gene Region and Type 2 Diabetes Mellitus in Han Chinese

BACKGROUND

Cytochrome P450 family 17 subfamily A member 1 (CYP17A1) gene encodes a key enzyme in the synthesis and metabolism of steroid hormones and has been associated with various factors, such as hypertension, insulin resistance, and polycystic ovary syndrome. However, whether the gene was associated with type 2 diabetes mellitus (T2DM) has not been reported yet. Therefore, we sought to investigate whether CYP17A1 was associated with T2DM and related traits among Han Chinese.

METHODS

Three tagging single nucleotide polymorphisms (rs1004467, rs17115149, and rs12413409), in the CYP17A1 gene region were selected and genotyped in a case-control study that included 440 diabetes and 1,320 control subjects. Effects of genetic loci were studied using univariate unconditional logistic regression and multivariate logistic regression analysis adjusted for age, sex, family history, body mass index, smoking, and drinking. Bioinformatics analysis was also conducted using the GEO DataSets and PROMO database to gain hints of possible mechanism.

RESULTS

Rs17115149 and rs12413409 polymorphisms were significantly associated with the risk of T2DM, even after adjusting for age, sex, family history, body mass index, smoking, and drinking. In stratified analyses, rs1004467 and rs12413409 showed significant association with T2DM in the older age group (≥65 years) and, in the case of rs12413409, the risk of T2DM was significant in men but not in women. Rs17115149 had significant association with T2DM in the hypertension subgroup, and rs12413409 in the non-hypertension subgroup. Moreover, rs12413409 showed significant association with plasma glucose levels in the recessive model (P = 0.020) among subjects not taking hypoglycemic measures. Bioinformatics analysis revealed significantly higher CYP17A1 gene expression in T2DM patients compared to healthy controls. Finally, the mutant T allele of the rs17115149 polymorphism allowed binding to the RBP-Jkappa transcription factor.

CONCLUSION

This is the first report to identify that variants rs1004467, rs17115149, and rs12413409 of CYP17A1, are related to plasma glucose levels and T2DM among Han Chinese. Our results suggest that CYP17A1 might constitute a risk gene for progression to T2DM.

Treatment with a DNA methyltransferase inhibitor feminizes zebrafish and induces long-term expression changes in the gonads

BACKGROUND

The role of epigenetic modifications such as DNA methylation during vertebrate sexual development is far from being clear. Using the zebrafish model, we tested the effects of one of the most common DNA methyltransferase (dnmt) inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC), which is approved for the treatment of acute myeloid leukaemia and is under active investigation for the treatment of solid tumours. Several dose-response experiments were carried out during two periods, including not only the very first days of development (0-6 days post-fertilization, dpf), as done in previous studies, but also, and as a novelty, the period of gonadal development (10-30 dpf).

RESULTS

Early treatment with 5-aza-dC altered embryonic development, delayed hatching and increased teratology and mortality, as expected. The most striking result, however, was an increase in the number of females, suggesting that alterations induced by 5-aza-dC treatment can affect sexual development as well. Results were confirmed when treatment coincided with gonadal development. In addition, we also found that the adult gonadal transcriptome of 5-aza-dC-exposed females included significant changes in the expression of key reproduction-related genes (e.g. cyp11a1, esr2b and figla), and that several pro-female-related pathways such as the Fanconi anaemia or the Wnt signalling pathways were downregulated. Furthermore, an overall inhibition of genes implicated in epigenetic regulatory mechanisms (e.g. dnmt1, dicer, cbx4) was also observed.

CONCLUSIONS

Taken together, our results indicate that treatment with a DNA methylation inhibitor can also alter the sexual development in zebrafish, with permanent alterations of the adult gonadal transcriptome, at least in females. Our results show the importance of DNA methylation for proper control of sexual development, open new avenues for the potential control of sex ratios in fish (aquaculture, population control) and call attention to possibly hidden long-term effects of dnmt therapy when used, for example, in the treatment of prepuberal children affected by some types of cancer.

Mesothelin promoter variants are associated with increased soluble mesothelin-related peptide levels in asbestos-exposed individuals

BACKGROUND

Soluble mesothelin-related peptide (SMRP) is a promising diagnostic biomarker for malignant pleural mesothelioma (MPM), but various confounders hinder its usefulness in surveillance programmes. We previously showed that a single nucleotide polymorphism (SNP) within the 3'untranslated region (3'UTR) of the mesothelin (MSLN) gene could affect the levels of SMRP.

OBJECTIVES

To focus on SNPs located within MSLN promoter as possible critical genetic variables in determining SMRP levels.

METHODS

The association between SMRP and SNPs was tested in 689 non-MPM subjects and 70 patients with MPM. Reporter plasmids carrying the four most common haplotypes were compared in a dual luciferase assay, and in silico analyses were performed to investigate the putative biological role of the SNPs.

RESULTS

We found a strong association between serum SMRP and variant alleles of rs3764247, rs3764246 (in strong linkage disequilibrium with rs2235504) and rs2235503 in non-MPM subjects. Inclusion of the genotype information led to an increase in SMRP specificity from 79.9% to 85.5%. Although not statistically significant, the group with MPM showed the same trend of association. According to the in vitro luciferase study, rs3764247 itself had a functional role. In silico approaches showed that the binding sites for transcription factors such as Staf and ZNF143 could be affected by this SNP. The other SNPs were shown to interact with each other in a more complex way.

CONCLUSIONS

These data support the suggestion that SMRP performance is affected by individual (ie, genetic) variables and that MSLN expression is influenced by SNPs located within the promoter regulatory region.

Association of single nucleotide polymorphisms in UBR2 gene with idiopathic aspermia or oligospermia in Sichuan, China

The associations between three single nucleotide polymorphisms (SNPs; rs3749897, rs16895863 and rs373341) of UBR2 gene and idiopathic aspermia or oligospermia were investigated in this study by a case-control experiment with 149 fertile and 316 infertile men, including 244 patients with idiopathic aspermia and 72 patients with severe oligospermia. The time-of-flight mass spectrometry (Sequenom MassARRAY^®  system) was used in this study. A significant difference between the oligospermia men (oligospermia group) and the fertile men (control group) was observed in this research (odds ratio [OR]: 2.764; 95% CI: 95% confidence interval [CI]: 1.171-6.525; P = 0.017), which could indicate that the combined AT-TC-CC genotype in the UBR2 gene (rs16895863, rs373341, rs3749897 respectively) is a possible risk of idiopathic oligospermia for men in Sichuan, China.

CYP17A1 and CYP2E1 variants associated with high altitude polycythemia in Tibetans at the Qinghai-Tibetan Plateau

Tibetans adapt to high altitude environments through low blood hemoglobin concentrations. Previous work has identified that CYP17A1 and CYP2E1 genes exhibit evidence of local positive selection for this Tibetan high-altitude adaptation. Nevertheless, despite this apparent genetic advantage, some Tibetans still develop high altitude polycythemia (HAPC) yet the reasons for this remain unknown. We sought to determine if polymorphisms in CYP17A1 and CYP2E1 genes were associated with susceptibility to HAPC in Tibetans at the Qinghai-Tibetan Plateau in China. We enrolled 63 Tibetan HAPC patients and 131 healthy, age- and gender-matched control Tibetans. All subjects are from the Yushu area of Qinghai where the altitude is over 3500 m. Three SNPs of the CYP17A1 including rs3781287, rs11191548 and rs1004467, and four SNPs of CYP2E1 gene, including rs1536836, rs3813865, rs3813867 and rs743535, were genotyped by the Sequenom MassARRAY SNP assays. We discovered that SNP rs1004467 of the CYP17A1 gene and SNP rs3813865 of the CYP2E1 gene were significantly associated with HAPC risk. Furthermore, we identified a positive correlation between these two SNPs and plasma hemoglobin levels. Thus, taken together, our study is the first to our knowledge to show that polymorphisms in the rs1004467 SNP of CYP17A1 and rs3813865 SNP of CYP2E1 correlate with susceptibility to HAPC.

Transcriptome profiling identifies differentially expressed genes in Huoyan goose ovaries between the laying period and ceased period

The Huoyan goose is famous for its high egg-laying performance and is listed as a nationally protected domestic animal by the Chinese government. To elucidate the key regulatory genes involved in Huoyan goose egg laying, RNA from ovarian tissue during the ceased and laying periods was sequenced using the Illumina HiSeq 2000 sequencing platform. More than 12 million reads were produced in ceased and laying libraries that included 11,896,423 and 12,534,799 clean reads, respectively. More than 20% of the reads were matched to the reference genome, and 23% of the reads were matched to reference genes. Genes with a false discovery rate (FDR) ≤0.001 and log₂ratio ≧1 or ≤−1 were characterized as differentially expressed, and 344 up-regulated and 344 down-regulated genes were classified into functional categories. Twelve genes that are mainly involved in pathways for reproduction regulation, such as steroid hormone biosynthesis, GnRH signaling pathways, oocyte meiosis, progesterone-mediated oocyte maturation, steroid biosynthesis, calcium signaling pathways, and G-protein coupled receptor signaling pathway were selected for validation by a quantitative real-time polymerase chain reaction (qRT-PCR) analysis, the qRT-PCR results are consistent with the general expression patterns of those genes from the Illumina sequencing. These data provide comprehensive gene expression information at the transcriptional level that might increase our understanding of the Huoyan goose's reproductive biology.

Genome-wide associations between genetic and epigenetic variation influence mRNA expression and insulin secretion in human pancreatic islets

Genetic and epigenetic mechanisms may interact and together affect biological processes and disease development. However, most previous studies have investigated genetic and epigenetic mechanisms independently, and studies examining their interactions throughout the human genome are lacking. To identify genetic loci that interact with the epigenome, we performed the first genome-wide DNA methylation quantitative trait locus (mQTL) analysis in human pancreatic islets. We related 574,553 single nucleotide polymorphisms (SNPs) with genome-wide DNA methylation data of 468,787 CpG sites targeting 99% of RefSeq genes in islets from 89 donors. We identified 67,438 SNP-CpG pairs in cis, corresponding to 36,783 SNPs (6.4% of tested SNPs) and 11,735 CpG sites (2.5% of tested CpGs), and 2,562 significant SNP-CpG pairs in trans, corresponding to 1,465 SNPs (0.3% of tested SNPs) and 383 CpG sites (0.08% of tested CpGs), showing significant associations after correction for multiple testing. These include reported diabetes loci, e.g. ADCY5, KCNJ11, HLA-DQA1, INS, PDX1 and GRB10. CpGs of significant cis-mQTLs were overrepresented in the gene body and outside of CpG islands. Follow-up analyses further identified mQTLs associated with gene expression and insulin secretion in human islets. Causal inference test (CIT) identified SNP-CpG pairs where DNA methylation in human islets is the potential mediator of the genetic association with gene expression or insulin secretion. Functional analyses further demonstrated that identified candidate genes (GPX7, GSTT1 and SNX19) directly affect key biological processes such as proliferation and apoptosis in pancreatic β-cells. Finally, we found direct correlations between DNA methylation of 22,773 (4.9%) CpGs with mRNA expression of 4,876 genes, where 90% of the correlations were negative when CpGs were located in the region surrounding transcription start site. Our study demonstrates for the first time how genome-wide genetic and epigenetic variation interacts to influence gene expression, islet function and potential diabetes risk in humans.

Inter-individual variation in genetics and epigenetics affects biological processes and disease susceptibility. However, most studies have investigated genetic and epigenetic mechanisms independently and to uncover novel mechanisms affecting disease susceptibility there is a highlighted need to study interactions between these factors on a genome-wide scale. To identify novel loci affecting islet function and potentially diabetes, we performed the first genome-wide methylation quantitative trait locus (mQTL) analysis in human pancreatic islets including DNA methylation of 468,787 CpG sites located throughout the genome. Our results showed that DNA methylation of 11,735 CpGs in 4,504 unique genes is regulated by genetic factors located in cis (67,438 SNP-CpG pairs). Furthermore, significant mQTLs cover previously reported diabetes loci including KCNJ11, INS, HLA, PDX1 and GRB10. We also found mQTLs associated with gene expression and insulin secretion in human islets. By performing causality inference tests (CIT), we identified CpGs where DNA methylation potentially mediates the genetic impact on gene expression and insulin secretion. Our functional follow-up experiments further demonstrated that identified mQTLs/genes (GPX7, GSTT1 and SNX19) directly affect pancreatic β-cell function. Together, our study provides a detailed map of genome-wide associations between genetic and epigenetic variation, which affect gene expression and insulin secretion in human pancreatic islets.