The expression profiles of cyp19a1, sf-1, esrs and gths in the brain-pituitary during gonadal sex differentiation in juvenile Japanese eels.

Eels are gonochoristic species whose gonadal differentiation initiates at the yellow eel stage and is influenced by environmental factors. We revealed some sex-related genes were sex dimorphically expressed in gonads during gonadal sex differentiation of Japanese eel (Anguilla japonica); however, the expression of sex-related genes in the brain-pituitary during gonadal sex differentiation in eels is still unclear. This study aimed to investigate the sex-related gene expressions in the brain-pituitary and tried to clarify their roles in the brain and gonads during gonadal sex differentiation. Based on our previous histological study, the control eels developed as males, and estradiol-17ß (E2) was used for feminization. Our results showed that during testicular differentiation, the brain cyp19a1 transcripts and aromatase proteins were increased significantly; moreover, the cyp19a1, sf-1, foxl2s, and esrs (except gperb) transcripts in the midbrain/pituitary also were increased significantly. Forebrain gnrh1 transcripts increased slightly during gonadal differentiation of both sexes, but the gnrhr1b and gnrhr2 transcripts in the midbrain/pituitary were stable during gonadal differentiation. The expression levels of gths and gh in the midbrain/pituitary were significantly increased during testicular differentiation and were much higher in males than in E2-feminized females. These results implied that endogenous estrogens might play essential roles in the brain/pituitary during testicular differentiation, sf-1, foxl2s, and esrs may have roles in cyp19a1 regulation in the midbrain/pituitary of Japanese eels. For the GnRH-GTH axis, gths, especially fshb, may be regulated by esrs and involved in regulating testicular differentiation and development in Japanese eels.

Nuclear lncRNA NORSF reduces E2 release in granulosa cells by sponging the endogenous small activating RNA miR-339.

BACKGROUND: Functioning as a competing endogenous RNA (ceRNA) is the main action mechanism of most cytoplasmic lncRNAs. However, it is not known whether this mechanism of action also exists in the nucleus. RESULTS: We identified four nuclear lncRNAs that are presented in granulosa cells (GCs) and were differentially expressed during sow follicular atresia. Notably, similar to cytoplasmic lncRNAs, these nuclear lncRNAs also sponge miRNAs in the nucleus of GCs through direct interactions. Furthermore, NORSF (non-coding RNA involved in sow fertility), one of the nuclear lncRNA acts as a ceRNA of miR-339. Thereby, it relieves the regulatory effect of miR-339 on CYP19A1 encoding P450arom, a rate-limiting enzyme for E2 synthesis in GCs. Interestingly, miR-339 acts as a saRNA that activates CYP19A1 transcription and enhances E2 release by GCs through altering histone modifications in the promoter by directly binding to the CYP19A1 promoter. Functionally, NORSF inhibited E2 release by GCs via the miR-339 and CYP19A1 axis. CONCLUSIONS: Our findings highlight an unappreciated mechanism of nuclear lncRNAs and show it acts as a ceRNA, which may be a common lncRNA function in the cytoplasm and nucleus. We also identified a potential endogenous saRNA for improving female fertility and treating female infertility.

Charged Amino Acids in the Transmembrane Helix Strongly Affect the Enzyme Activity of Aromatase.

Estrogens play critical roles in embryonic development, gonadal sex differentiation, behavior, and reproduction in vertebrates and in several human cancers. Estrogens are synthesized from testosterone and androstenedione by the endoplasmic reticulum membrane-bound P450 aromatase/cytochrome P450 oxidoreductase complex (CYP19/CPR). Here, we report the characterization of novel mammalian CYP19 isoforms encoded by CYP19 gene copies. These CYP19 isoforms are all defined by a combination of mutations in the N-terminal transmembrane helix (E42K, D43N) and in helix C of the catalytic domain (P146T, F147Y). The mutant CYP19 isoforms show increased androgen conversion due to the KN transmembrane helix. In addition, the TY substitutions in helix C result in a substrate preference for androstenedione. Our structural models suggest that CYP19 mutants may interact differently with the membrane (affecting substrate uptake) and with CPR (affecting electron transfer), providing structural clues for the catalytic differences.

Cyp19a1a Promotes Ovarian Maturation through Regulating E2 Synthesis with Estrogen Receptor 2a in Pampus argenteus (Euphrasen, 1788).

In the artificial breeding of Pampus argenteus (Euphrasen, 1788), female fish spawn before male release sperm, which indicates rapid ovarian development. In fish, aromatase is responsible for converting androgens into estrogens and estrogen plays a crucial role in ovarian development. In this study, we aimed to investigate the potential role of brain-type and ovarian-type aromatase to study the rapid ovarian development mechanism. The results showed that cyp19a1a was mainly expressed in the ovary and could be classified as the ovarian type, whereas cyp19a1b could be considered as the brain type for its expression was mainly in the brain. During ovarian development, the expression of cyp19a1a in the ovary significantly increased from stage IV to stage V and Cyp19a1a signals were present in the follicle cells, while cyp19a1b expression in the pituitary gland decreased from stage IV to stage V. To further investigate the function of Cyp19a1a, recombinant Cyp19a1a (rCyp19a1a) was produced and specific anti-Cyp19a1a antiserum was obtained. The expressions of cyp19a1a, estrogen receptors 2 alpha (esr2a), and androgen receptor alpha (arα) were significantly upregulated in the presence of rCyp19a1a. Meanwhile, cyp19a1a was expressed significantly after E2 treatment in both ovarian and testicular tissue culture. Taken together, we found two forms of aromatase in silver pomfret. The ovarian-type aromatase might play an important role in ovarian differentiation and maturation, and participate in E2 synthesis through co-regulation with esr2a. The brain-type aromatase cyp19a1b might be involved in the regulation of both brain and gonadal development.

Higher intake of ß-glucan impairs reproduction in a female teleost, Tor putitora (Hamilton, 1822).

Although the immuno-modulatory and stress-relieving properties of ß-glucan is well elucidated in humans and other animal models, including fish, its role as a dietary supplement on reproduction is extremely scarce. Therefore, in this study, adult female fish were fed one of four test diets having 0 (control), 0.5, 1, and 1.5% ß-D-glucan for 130 days and its effect on reproductive performance, ovarian and liver histology, sex hormones, and transcript abundance of selected reproduction-related genes was assessed. Low dietary intake of ß-glucan improved fertilization and hatching rates (p<0.05). The relative fecundity and percentage of spawning females were higher (non-significant) in 0.5% ß-glucan-fed groups. Surprisingly, even after 130 days, spawning did not occur in 1.5% ß-glucan-fed individuals. Irrespective of ß-glucan intake, all the brooders recorded similar plasma 17ß-estradiol and maturation-inducing hormone (p>0.05). Higher intake of ß-glucan (1.5%) upregulated aromatase genes without a parallel increase in 17ß-estradiol. However, plasma vitellogenin increased with increasing ß-glucan up to 1.0% then declined at 1.5% (p<0.05). The fish that received control, 0.5, and 1.5% ß-glucan recorded similar vitellogenin levels in their plasma. Significantly higher plasma cortisol was evidenced in 1.5% ß-glucan fed brooders (p<0.05). Histologically, higher follicular atresia and leaking of yolk material was evidenced in 1.5% ß-glucan-fed group. Liver histology revealed the highest nutrient/lipid accumulation in fish that received 1.0% and 1.5% ß-glucan. This study demonstrated the stimulatory effect of ß-glucan intake at a lower dose (0.5%) on reproduction. However, higher intake (1.5%) could perturb normal reproductive function in a fish model and caused an increased number of atretic follicles leading to spawning/reproductive failure.

Expression characteristics of the cyp19a1b aromatase gene and its response to 17ß-estradiol treatment in largemouth bass (Micropterus salmoides).

To investigate the regulatory role of the cyp19a1b aromatase gene in the sexual differentiation of largemouth bass (Micropterus salmoides, LMB), we obtained the full-length cDNA sequence of cyp19a1b using rapid amplification of cDNA ends technique. Tissue expression characteristics and feedback with 17-ß-estradiol (E2) were determined using quantitative real-time PCR (qRT-PCR), while gonad development was assessed through histological section observations. The cDNA sequence of LMB cyp19a1b was found to be1950 base pairs (bp) in length, including a 5' untranslated region of 145 bp, a 3' untranslated region of 278 bp, and an open reading frame encoding a protein consisting of 1527 bp that encoded 508 amino acids. The qRT-PCR results indicated that cyp19a1b abundantly expressed in the brain, followed by the gonads, and its expression in the ovaries was significantly higher than that observed in the testes (P < 0.05). After feeding fish with E2 for 30 days, the expression of cyp19a1b in the pseudo-female gonads (XY-F) was significantly higher than that in males (XY-M) (P < 0.05), whereas expression did not differ significantly between XX-F and XY-F fish (P > 0.05). Although the expression of cyp19a1b in XY-F and XX-F fish was not significantly different after 60 days (P>0.05), both exhibited significantly higher levels than that of XY-M fish (P<0.05). Histological sections analysis showed the presence of oogonia in both XY-F and XX-F fish at 30 days, while spermatogonia were observed in XY-M fish. At 60 days, primary oocytes were abundantly observed in both XY-F and XX-F fish, while a few spermatogonia were visible in XY-M fish. At 90 days, the histological sections' results showed that a large number of oocytes were visible in XY-F and XX-F fish. Additionally, the gonads of XY-M fish contained numerous spermatocytes. These results suggest that cyp19a1b plays a pivotal role in the development of ovaries and nervous system development in LMB.

Disruption of dmrt1 rescues the all-male phenotype of the cyp19a1a mutant in zebrafish - a novel insight into the roles of aromatase/estrogens in gonadal differentiation and early folliculogenesis.

Sex determination and differentiation are complex processes controlled by many different factors; however, the relationships among these factors are poorly understood. Zebrafish gonadal differentiation exhibits high plasticity involving multiple factors and pathways, which provides an excellent model for investigating the interactions between them. Ovarian aromatase (cyp19a1a) and dmrt1 are key factors in directing vertebrate ovary and testis differentiation, respectively. Knockout of zebrafish cyp19a1a leads to all-male offspring, whereas the loss of dmrt1 results in a female-biased sex ratio. In the present study, we established dmrt1-/- ;cyp19a1a-/- double mutant zebrafish and discovered that the introduction of the dmrt1 mutation into the cyp19a1a mutant could rescue the all-male phenotype of the latter. Interestingly, despite the lack of aromatase/estrogens, the follicles in the ovary of the rescued cyp19a1a mutant could develop normally up to the previtellogenic stage. Further evidence suggested the ovarian aromatase directed ovarian differentiation by suppressing dmrt1 expression via nuclear estrogen receptors (nERs). Our results provide solid evidence for an interaction between cyp19a1a and dmrt1 in zebrafish gonadal differentiation, and for the dispensability of estrogens in controlling early folliculogenesis.

Loss of dmrt1 restores zebrafish female fates in the absence of cyp19a1a but not rbpms2a/b.

Sex determination and differentiation is a complex process regulated by multiple factors, including factors from the germline or surrounding somatic tissue. In zebrafish, sex-determination involves establishment of a bipotential ovary that undergoes sex-specific differentiation and maintenance to form the functional adult gonad. However, the relationships among these factors are not fully understood. Here, we identify potential Rbpms2 targets and apply genetic epistasis experiments to decipher the genetic hierarchy of regulators of sex-specific differentiation. We provide genetic evidence that the crucial female factor rbpms2 is epistatic to the male factor dmrt1 in terms of adult sex. Moreover, the role of Rbpms2 in promoting female fates extends beyond repression of Dmrt1, as Rbpms2 is essential for female differentiation even in the absence of Dmrt1. In contrast, female fates can be restored in mutants lacking both cyp19a1a and dmrt1, and prolonged in bmp15 mutants in the absence of dmrt1. Taken together, this work indicates that cyp19a1a-mediated suppression of dmrt1 establishes a bipotential ovary and initiates female fate acquisition. Then, after female fate specification, Cyp19a1a regulates subsequent oocyte maturation and sustains female fates independently of Dmrt1 repression.

TGF-ß1 induced activations of Smad2 and miRNAs inhibit SF-1- and LRH-1-dependent CYP19 expression in rat Leydig cells†.

P450 aromatase, encoded by the Cyp19 gene, catalyzes the synthesis of estrogen, which is crucial for mammalian germ cell differentiation. We have previously shown that transforming growth factor beta 1 (TGF-ß1) attenuated the accumulation of steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) and eventually reduced the transcription of Cyp19 in rat Leydig cells (LCs). Here, we report that TGF-ß1 treatment-induced phosphorylation of Smad2 and decreased the expression levels of SF-1 and LRH-1 by elevating the expression levels of microRNA-21-3p and microRNA-339-5p in vivo and in vitro. Furthermore, both TGF-ß1 treatment and over-expression of Smad2 inhibited the SF-1 or LRH-1-regulated promoter activity of the Cyp19 gene, and p-Smad2 physically interacted with SF-1 and LRH-1. Our findings collectively suggest that TGF-ß1 may inhibit the expression of CYP19 in LCs mainly through two ways. On the one hand, TGF-ß1 acts through Smad2 to repress the accumulation of SF-1 and LRH-1 at post-transcriptional level by upregulating specific microRNAs. On the other hand, TGF-ß1 inhibits the transcriptional activity of Cyp19 through the interaction of p-Smad2 with SF-1/LRH-1.

Decamethylcyclopentasiloxane affects estradiol production in female rats but not H295R cells.

Sex hormones, such as androgens and estrogens, are predominantly produced in the gonads (ovaries and testes) and adrenal cortex. Endocrine-disrupting chemicals (EDCs) are substances that mimic, block, or interfere with hormones in the endocrine systems of humans and organisms. EDCs mainly act via nuclear receptors and steroidogenesis-related enzymes. In the OECD conceptual framework for testing and assessment of EDCs, several well-known assays are used to identify the potential disruption of nuclear receptors both in vivo and in vitro, whereas the H295R steroidogenesis assay is the only assay that detects the disruption of steroidogenesis. Forskolin and prochloraz are often used as positive controls in the H295R steroidogenesis assay. Decamethylcyclopentasiloxane (D5) was suspected one of EDCs, but the effects of D5 on steroidogenesis remain unclear. To establish a short-term in vivo screening method that detects the disruption of steroidogenesis, rats in the present study were fed a diet containing forskolin, prochloraz, or D5 for 14 days. Forskolin increased plasma levels of 17ß-estradiol (E2) and testosterone as well as the mRNA level of Cyp19 in both the adrenal glands and ovaries. Prochloraz induced the loss of cyclicity in the sexual cycle and decreased plasma levels of E2 and testosterone. D5 increased E2 levels and shortened the estrous cycle in a dose-dependent manner; however, potential endocrine disruption was not detected in the H295R steroidogenesis assay. These results demonstrate the importance of comprehensively assessing the endocrine-disrupting effects of chemicals on steroidogenesis in vivo.

Genetic variants in the genes of the sex steroid hormone metabolism and depressive symptoms during and after pregnancy.

PURPOSE: The aim of this study was to conduct an association analysis of depressive symptoms and polymorphisms in the ESR1, PGR, CYP19A1, and COMT genes in pregnant and postpartum women. METHODS: The Franconian Maternal Health Evaluation Study (FRAMES) recruited healthy pregnant women prospectively for assessment of maternal and fetal health. The German version of the 10-item Edinburgh Postnatal Depression Scale (EPDS) was completed at three time points in this prospective cohort study. Visit 1 was at study entry in the third trimester of pregnancy, visit 2 was shortly after birth, and visit 3 was 6-8 months after birth. Germline DNA and depression measurements from 361 pregnant women were available for analysis. Six single nucleotide polymorphisms (SNPs) in the above-mentioned genes were genotyped. After reconstruction of haplotypes for PGR (rs1042838 and rs10895068) and CYP19A1 (rs10046 and rs4646), a multifactorial linear mixed model was applied to the data to describe the association between haplotypes and depression values. The single SNPs for ESR1 (rs488133) and COMT (rs4680) were analyzed separately using linear mixed models analogously. RESULTS: The mean antepartum EPDS measurement was 5.1, the mean postpartal measurement after 48-72 h was 3.5, and the mean value 6-8 months postpartum was 4.2. The SNPs in PGR were reconstructed into three haplotypes. The most common haplotype was GG, with 63.43% of patients carrying two copies and 33.52% carrying one copy. For haplotype GA, the group of carriers of two copies (0.28%) was combined with the carriers of one copy (9.70%). Haplotype reconstruction using CYP19A1 SNPs resulted in three haplotypes. The most common haplotype was TC, with 25.48% of patients carrying two copies and 51.52% one copy. None of the haplotype blocks and neither of the two single SNPs showed any significant associations with EPDS values. CONCLUSIONS: The candidate haplotypes analyzed in PGR and CYP19A1 and single SNPs in ESR1 and COMT did not show any association with depression scores as assessed by EPDS in this cohort of healthy unselected pregnant women.

FoxH1 Represses the Promoter Activity of cyp19a1a in the Ricefield Eel (Monopterus albus).

Forkhead box H1 (FoxH1) is a sexually dimorphic gene in Oreochromis niloticus, Oplegnathus fasciatus, and Acanthopagrus latus, indicating that it is essential for gonadal development. In the present study, the molecular characteristics and potential function of FoxH1 and the activation of the cyp19a1a promoter in vitro were evaluated in Monopterus albus. The levels of foxh1 in the ovaries were three times higher than those in the testes and were regulated by gonadotropins (Follicle-Stimulating Hormone and Human Chorionic Gonadotropin). FoxH1 colocalized with Cyp19a1a in the oocytes and granulosa cells of middle and late vitellogenic follicles. In addition, three FoxH1 binding sites were identified in the proximal promoter of cyp19a1a, namely, FH1 (-871/-860), FH2 (-535/-524), and FH3 (-218/-207). FoxH1 overexpression significantly attenuated the activity of the cyp19a1a promoter in CHO cells, and FH1/2 mutation increased promoter activity. Taken together, these results suggest that FoxH1 may act as an important regulator in the ovarian development of M. albus by repressing cyp19a1a promoter activity, which provides a foundation for the study of FoxH1 function in bony fish reproductive processes.

Contribution of CYP19A1, CYP1A1, and CYP1A2 polymorphisms in coronary heart disease risk among the Chinese Han population.

The previous study has pointed to that endogenous CYP metabolites play an important role in the pathogenesis of coronary heart disease (CHD). The study aimed to identify the association of CYP19A1, CYP1A1, and CYP1A2 polymorphisms with CHD susceptibility in a Chinese Han population. A total of 960 genetically unrelated participants consist of 480 CHD patients and 480 healthy controls were enrolled. Nine SNPs in CYP19A1, CYP1A1, and CYP1A2 were randomly selected and genotyped using the Agena MassARRAY platform. Logistic regression analysis was used for the relationship between selected SNPs and CHD susceptibility by calculating odds ratios (OR) with 95% confidence intervals (CI) adjusted for age and gender. The distribution of clinical characteristics in different genotypes was evaluated by one-way analysis of variance (ANOVA). CYP1A2 rs2470890 TT genotype had a higher CHD risk compared with CC genotype (OR = 3.06, p = 0.032) or CC-CT genotype (OR = 3.04, p = 0.033). Moreover, the contribution of CYP19A1 and CYP1A2 polymorphisms to CHD susceptibility was associated with age, gender, and clinical phenotypes (course of the disease and Gensini score). Besides, CYP1A2 rs762551 was related to serum levels of red blood cell, triglyceride, total cholesterol, and low-density lipoprotein cholesterol (LDL-C, p < 0.05). Our findings provided scientific evidence about CYP19A1, CYP1A1, and CYP1A2 polymorphisms on CHD incidence.

Taurine promotes estrogen synthesis by regulating microRNA-7a2 in mice ovarian granulosa cells.

Taurine, acting as a free amino acid, is widely distributed and plays multiple functions, including its regulating effect on estrogen synthesis in ovary. However, the mechanisms of taurine regulating estrogen synthesis in granulosa cells are not well understood. In this study, we identify whether microRNA-7a2 (miR-7a2) is involved in the signaling of taurine regulating estrogen synthesis in mouse granulosa cells for the first time. The results demonstrated that taurine transporter (TauT) co-localized with miR-7a in mouse ovarian granulose cells. Further, taurine treatment markedly enhanced the expression of miR-7a and Cyp19a1 in mouse ovaries and increased serum 17ß-estradiol (E2) concentration. Meanwhile, miR-7a2 knockout reversed the effect of taurine on E2. In addition, Golgi apparatus protein 1 (Glg1), a downstream target gene of miR-7a2, was significantly down-regulated by taurine, while Glg1 knockdown markedly increased the Cyp19a1 expression and E2 synthesis. Moreover, taurine affected miR-7a expression via activating p38 signaling. These results suggest that taurine promotes E2 synthesis through p38/miR-7a/Glg1/Cyp19a1 signaling pathway, which is crucial to understand the function and mechanism of taurine on estrogen synthesis.

CC chemokine ligand 2 (CCL2) stimulates aromatase gene expression in mammary adipose tissue.

Obesity is a risk factor for postmenopausal breast cancer. Obesity-related inflammation upregulates aromatase expression, the rate-limiting enzyme for estrogen synthesis, in breast adipose tissue (BAT), increasing estrogen production and cancer risk. The regulation of aromatase gene (CYP19A1) in BAT is complex, and the mechanisms linking obesity and aromatase dysregulation are not fully understood. An obesity-associated factor that could regulate aromatase is the CC chemokine ligand (CCL) 2, a pro-inflammatory factor that also activates signaling pathways implicated in CYP19A1 transcription. By using human primary breast adipose stromal cells (ASCs) and aromatase reporter (hARO-Luc) mouse mammary adipose explants, we demonstrated that CCL2 enhances the glucocorticoid-mediated CYP19A1 transcription. The potential mechanism involves the activation of PI.4 via ERK1/2 pathway. We also showed that CCL2 contributes to the pro-inflammatory milieu and aromatase expression in obesity, evidenced by increased expression of CCL2 and CYP19A1 in mammary tissues from obese hARO-Luc mice, and subcutaneous adipose tissue from obese women. In summary, our results indicate that postmenopausal obesity may promote CCL2 production in BAT, leading to exacerbation of the menopause-related inflammatory state and further stimulation of local aromatase and estrogens. These results provide new insights into the regulation of aromatase and may aid in finding approaches to prevent breast cancer.

Deficiency of Wnt10a causes female infertility via the ß-catenin/Cyp19a1 pathway in mice.

Wnt signaling is relevant for a wide range of biological processes, including reproductive function. The function of Wnt10a in female fertility, however, remains obscure. In the present study, we explored the structure and function of the female reproductive organs in Wnt10a knockout (KO) mice. The expression of ß-catenin signaling was significantly lower in the ovaries of the Wnt10a KO mice compared with wild-type (WT) mice. In addition, the estrous cycles were disrupted, ovarian follicles were diminished, and endometria were thinner, accompanied by lower serum estrogen levels, and higher testosterone and progesterone levels in Wnt10a KO mice. The expression of the ovarian cytochrome P450 family 19 subfamily A member 1 (Cyp19a1) was significantly lower in Wnt10a KO mice. We detected no significant changes in the levels of the gonadotropins between WT and KO mice. Together, our findings indicate that deficiency of Wnt10a causes female infertility through ß-catenin and Cyp19a1signaling pathways in mice.

Transcriptional regulation of CYP19A1 expression in chickens: ESR1, ESR2 and NR5A2 form a functional network.

Aromatase, encoded by CYP19A1, is responsible for the conversion of androgen to estrogen, which plays a vital role in the development and function of the ovary and functions in many other physiological processes in both sexes. Instead of being expressed in ovarian granulosa cells, as in mammals, CYP19A1 is expressed in chickens in the theca cells of ovarian follicles, and the mechanism of CYP19A1 expression regulation remains unknown. Here, using immunofluorescence and western blotting assay, we first confirmed that CYP19A1 and FOXL2 (Forkheadbox L2) were coexpressed in pre-granulosa cells of female chicken embryonic gonads, while FOXL2 did not affect aromatase expression at embryonic stages. Second, our research showed that CYP19A1, ESR1 (estrogen receptor alpha), ESR2 (estrogen receptor beta) and NR5A2 (liver receptor homologue-1) were coexpressed in the theca cell layers of chicken small yellow follicles. There was cross-talk between CYP19A1 and candidate transcription factors (ESR1, ESR2 and NR5A2), which was identified by generating a reliable theca cell culture model. Using luciferase assays in theca cells and chicken embryonic fibroblast (DF-1) cells, the results suggested that ESR1 and NR5A2 had potential effects on CYP19A1 promoter activity in chickens. Overexpression of ESR1, ESR2 and NR5A2 in chicken embryonic fibroblast (DF-1) cells upregulated the protein expression of CYP19A1, mutually restricted each other and formed a potential regulatory network to coordinate the expression of CYP19A1. To conclude, our results indicated that FOXL2 cannot regulate the expression of CYP19A1 at chicken embryonic stages and after sexual maturity, ESR1, ESR2 and NR5A2 form a functional network to affect the expression of CYP19A1. These results laid a foundation for further research on the transcriptional regulation of chicken aromatase.

Association of CYP19A1 rs28757157 polymorphism with lung cancer risk in the Chinese Han population.

BACKGROUND: Lung cancer is the leading cause of cancer death globally. Recent studies have revealed that CYP19A1 gene plays a crucial role in cancer initiation and development. The aim of this study was to assess the association of CYP19A1 genetic polymorphisms with the risk of lung cancer in the Chinese Han population. METHODS: This study randomly recruited 489 lung cancer patients and 467 healthy controls. The genotypes of four single nucleotide polymorphisms (SNPs) of the CYP19A1 gene were identified by the Agena MassARRY technique. Genetic model analysis was used to assess the association between genetic variations and lung cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the effect of four selected SNPs on lung cancer risk. RESULTS: CYP19A1 rs28757157 might contribute to an increased risk of lung cancer (p = 0.025, OR = 1.30, 95% CI 1.03-1.64). In stratified analysis, rs28757157 was associated with an increased cancer risk in the population aged under 60 years, females, smokers, and drinkers. Besides, rs3751592 and rs59429575 were also identified as risk biomarkers in the population under 60 years and drinkers. Meanwhile, a relationship between an enhanced risk of squamous cell carcinoma and rs28757157 was found, while the rs3751592 CC genotype was identified as a risk factor for lung adenocarcinoma development. CONCLUSIONS: This study has identified revealed that the three SNPs (rs28757157, rs3751592, and rs59429575) of CYP19A1 are associated with lung cancer in the Chinese Han population. These findings will provide theoretical support for further functional studies of CYP19A1 in lung cancer.

Role of endocrine disruption in toxicity of 6-benzylaminopurine (6-BA) to early-life stages of Zebrafish.

6-benzylaminopurine (6-BA), classified as a "plant hormone", is an important ingredient in production of "toxic bean sprouts". Although there is no direct evidence of adverse effects, its hazardous effects have received some attention and aroused furious debate between proponents and environmental regulators. In this study, potential adverse effects of 6-BA were investigated by exposing zebrafish in vivo to 0.2 - 25 mg 6-BA/L. Results indicated that, when exposure was limited to early-life stage (4-36 hpf), 20 mg 6-BA/L caused early hatching, abnormal spontaneous movement, and precocious hyperactivity in zebrafish embryos/larvae. While under a continuous exposure regime, 6-BA at 0.2 mg/L was able to cause hyperactive locomotion and transcription of genes related to neurogenesis (gnrh3 and nestin) and endocrine systems (cyp19a and fshb) in 5 dpf larvae. Quantification by use of LC/MS indicated bioaccumulation of 6-BA in zebrafish increased when exposed to 0.2 or 20 mg 6-BA/L. These results suggested that 6-BA could accumulate in aquatic organisms and disrupt neuro-endocrine systems. Accordingly, exposure to 0.2 mg 6-BA/L increased production of estradiol (E2) and consequently E2/T ratio in zebrafish larvae, which directly indicated 6-BA is estrogenic. In silico simulations demonstrated potential for binding of 6-BA to estrogen receptor alpha (ERa) and cytochrome P450 aromatase (CYP19A). Therefore, induction of estrogenic effects, via potential interactions with hormone receptors or disturbance of downstream transcription signaling, was possible mechanism underlying the toxicity of 6-BA. Taken together, these findings demonstrate endocrine disrupting properties of 6-BA, which suggest concerns about risks posed to endocrine systems.

MicroRNA-7a2 Contributes to Estrogen Synthesis and Is Modulated by FSH via the JNK Signaling Pathway in Ovarian Granulosa Cells.

MicroRNA-7a2 (miR-7a2) plays fundamental roles in the female reproductive axis, and estrogen is indispensable for maintaining ovary function. However, the interaction between miR-7a2 and ovarian function is unclear. The present study aimed to determine whether and how miR-7a2 functions in estrogen synthesis. Firstly, the results verified that miR-7a was highly expressed in ovarian granulosa cells. The knockout (KO) of miR-7a2 caused infertility and abnormal ovarian function in mice. Concomitantly, the Cyp19a1 expression and estrogen synthesis were significantly inhibited, which was validated in primary granulosa cells. The mice transplanted with miR-7a2 KO ovaries showed similar results; however, estrogen supplementation reversed infertility. In the in vitro experiment, follicle-stimulating hormone (FSH) significantly improved the expression of miR-7a and Cyp19a1 and the synthesis of estrogen. However, the miR-7a2 KO markedly reversed the function of FSH. Also, FSH upregulated miR-7a by activating the (c-Jun N-terminal kinase) JNK signaling pathway. In addition, Golgi apparatus protein 1 (Glg1) was shown to be the target gene of miR-7a2. These findings indicated that miR-7a2 is essential for ovarian functions with respect to estrogen synthesis through the targeted inhibition of the expression of Glg1 and then promoting Cyp19a1 expression; the physiological process was positively regulated by FSH via the JNK signaling pathway in granulosa cells.