Because of evidence that an underlying disorder of androgen biosynthesis and/or metabolism is involved in the etiology of polycystic ovary syndrome, Gharani et al. (1997) examined the segregation of the genes coding for 2 enzymes in the synthesis and metabolism of androgens, cholesterol side chain cleavage enzyme (CYP11A) and aromatase (CYP19; 107910), with the PCO phenotype in 20 multiply affected families. All analyses excluded CYP19 cosegregation with PCO, demonstrating that this locus is not a major determinant of risk for the syndrome. On the other hand, their results provided evidence for linkage to the CYP11A locus. The data demonstrated that variation in CYP11A may play an important role in the etiology of the hyperandrogenemia that is a common characteristic of the polycystic ovary syndrome.
This gene is FSH induced. Identification of differential gene expression in in vitro FSH treated pig granulosa cells using suppression subtractive hybridization. Bonnet A et al. ABSTRACT: FSH, which binds to specific receptors on granulosa cells in mammals, plays a key role in folliculogenesis. Its biological activity involves stimulation of intercellular communication and upregulation of steroidogenesis, but the entire spectrum of the genes regulated by FSH has yet to be fully characterized. In order to find new regulated transcripts, however rare, we have used a Suppression Subtractive Hybridization approach (SSH) on pig granulosa cells in primary culture treated or not with FSH. Two SSH libraries were generated and 76 clones were sequenced after selection by differential screening. Sixty four different sequences were identified, including 3 novel sequences. Experiments demonstrated the presence of 25 regulated transcripts. A gene ontology analysis of these 25 genes revealed (1) catalytic; (2) transport; (3) signal transducer; (4) binding; (5) anti-oxidant and (6) structural activities. These findings may deepen our understanding of FSH's effects. Particularly, they suggest that FSH is involved in the modulation of peroxidase activity and remodelling of chromatin.
NCBI Summary:
This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the mitochondrial inner membrane and catalyzes the conversion of cholesterol to pregnenolone, the first and rate-limiting step in the synthesis of the steroid hormones. Two transcript variants encoding different isoforms have been found for this gene. The cellular location of the smaller isoform is unclear since it lacks the mitochondrial-targeting transit peptide. [provided by RefSeq, Jul 2008]
General function
Metabolism, Enzyme, Hydrolase, Peptidase/Protease
Comment
CYP11a encodes for a cholesterol side chain cleavage enzyme.
Synthesis and metabolism of androgens.
Cholesterol side-chain cleavage gene expression in theca cells: augmented transcriptional regulation and mRNA stability in polycystic ovary syndrome. Wickenheisser JK et al. Hyperandrogenism is characteristic of women with polycystic ovary syndrome (PCOS). Ovarian theca cells isolated from PCOS follicles and maintained in long-term culture produce elevated levels of progestins and androgens compared to normal theca cells. Augmented steroid production in PCOS theca cells is associated with changes in the expression of genes for several steroidogenic enzymes, including CYP11A1, which encodes cytochrome P450 cholesterol side-chain cleavage. Here, we further examined CYP11A1 gene expression, at both the transcriptional and post-transcriptional level in normal and PCOS theca cells propagated in long-term culture utilizing quantitative RT-PCR, functional promoter analyses, and mRNA degradation studies. The minimal element(s) that conferred increased basal and cAMP-dependent CYP11A1 promoter function were determined. CYP11A1 mRNA half-life in normal and PCOS theca cells was compared. Results of these cumulative studies showed that basal and forskolin stimulated steady state CYP11A1 mRNA abundance and CYP11A1 promoter activity were increased in PCOS theca cells. Deletion analysis of the CYP11A1 promoter demonstrated that augmented promoter function in PCOS theca cells results from increased basal regulation conferred by a minimal sequence between -160 and -90 bp of the transcriptional start site. The transcription factor, nuclear factor 1C2, was observed to regulate basal activity of this minimal CYP11A1 element. Examination of mRNA stability in normal and PCOS theca cells demonstrated that CYP11A1 mRNA half-life increased >2-fold, from approximately 9.22+/-1.62 h in normal cells, to 22.38+/-0.92 h in PCOS cells. Forskolin treatment did not prolong CYP11A1 mRNA stability in either normal or PCOS theca cells. The 5'-UTR of CYP11A1 mRNA confers increased basal mRNA stability in PCOS cells. In conclusion, these studies show that elevated steady state CYP11A1 mRNA abundance in PCOS cells results from increased transactivation of the CYP11A1 promoter and increased CYP11A1 mRNA stability.
Expression regulated by
LH
Comment
Epigenetic changes of the Cyp11a1 promoter region in granulosa cells undergoing luteinization during ovulation in female rats. Okada M et al. (2016) The ovulatory LH-surge induces rapid up-regulation of Cyp11a1 in granulosa cells (GCs) undergoing luteinization during ovulation. This study investigated in vivo whether epigenetic controls including histone modifications and DNA methylation in the promoter region are associated with the rapid increase of Cyp11a1 gene expression after LH-surge. GCs were obtained from rats treated with equine chorionic gonadotropin (CG) before (0 h) and 4 h and 12 h after human (h)CG injection. Cyp11a1 mRNA levels rapidly increased after hCG injection, reached a peak at 4 h, and then remained elevated until 12 h. DNA methylation status in the Cyp11a1 proximal promoter region was hypomethylated, and did not change at any of the observed times after hCG injection. Chromatin immunoprecipitation (ChIP) assays revealed that the levels of trimethylation of histone-H3-lysine-4 (H3K4me3), an active mark for transcription, increased, whereas the levels of H3K9me3 and H3K27me3, which are marks associated with repression of transcription, decreased in the Cyp11a1 proximal promoter after hCG injection. Chromatin condensation, which was analyzed using deoxyribonuclease-I, decreased in the Cyp11a1 proximal promoter after hCG injection. ChIP assays also showed that the binding activity of CAATT/enhancer-binding protein-β (C/EBPβ) to the Cyp11a1 proximal promoter increased after hCG injection. Luciferase assays revealed that the C/EBPβ binding site had transcriptional activity and contributed to basal and cAMP-induced Cyp11a1 expression. These results suggest that changes in histone modification and chromatin structure in the Cyp11a1 proximal promoter are involved in the rapid increase of Cyp11a1 gene expression in GCs undergoing luteinization during ovulation.//////////////////
Insulin-Like Growth Factor-I Activates Extracellularly Regulated Kinase to Regulate the P450 Side-Chain Cleavage Insulin-Like Response Element in Granulosa Cells. Denner L et al. IGF regulates steroidogenesis in granulosa cells through expression of the cytochrome P450 side-chain cleavage enzyme (P450scc) (CYP11A1), the rate-limiting enzyme in this biosynthetic process. We showed previously that the polypyrimidine tract-binding protein-associated splicing factor (PSF) acts as a repressor, whereas Sp1 is an activator, of P450 gene expression. The aim of the present study was to investigate IGF-stimulated ERK signaling regulating P450scc gene expression in the immortalized porcine granulosa cell line JC-410. We used a reporter gene under control of the IGF response element from the P450scc promoter. Inhibition of ERK phosphorylation with U0126 [1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenylmercapto)butadiene] blocked IGF-I induction of IGF response element reporter gene activity. Western blotting revealed that IGF-I treatment resulted in phosphorylation of ERK that was specifically inhibited by U0126. ERK activation led to phosphorylation of T739 (an ERK site) on Sp1 that was diminished by U0126 or overexpression of PSF. Coimmunoprecipitation and Western blotting of nuclear extracts showed that phosphorylated ERK (pERK) bound PSF under basal conditions. IGF-I caused dissociation of pERK from PSF. Finally, chromatin immunoprecipitation analysis showed that PSF and Sp1 constitutively occupy the P450scc promoter independent of IGF-I treatment. These events provide a potential molecular mechanism for release of PSF repression of P450scc expression by dissociation of pERK and subsequent pERK-mediated phosphorylation of Sp1 to drive transcriptional induction of the P450scc gene in the absence of altered binding of PSF or Sp1 to the promoter. Understanding IGF-I regulation of these critical ovarian signaling pathways is the first step to delineating ovarian hyperstimulation syndromes such as polycystic ovarian syndrome.
Ovarian localization
Granulosa
Comment
Expression of genes controlling steroid metabolism and action in granulosa-lutein cells of women with polycystic ovaries. Lerner A et al. (2019) Aberrant function of granulosa cells has been implicated in the pathophysiology of PCOS. GL cells were collected during oocyte retrieval for IVF/ICSI. RT-qPCR was used to compare gene expression between 12 control women, 12 with ovulatory PCO and 12 with anovulatory PCOS. To examine which genes are directly regulated by androgens, GL cells from an additional 12 control women were treated in-vitro with 10 nM dihydrotestosterone (DHT). Women with PCOS showed reduced expression of CYP11A1 3-fold (p = 0.005), HSD17B1 1.8-fold (p = 0.02) and increased expression of SULT1E1 7-fold (p = 0.0003). Similar results were seen in ovulatory women with PCO. GL cells treated with 10 nM DHT showed a 4-fold (p = 0.03) increase in expression of SULT1E1 and a 5-fold reduction in SRD5A1 (p = 0.03). These findings support the notion that aberrant regulation of steroid metabolism or action play a part in ovarian dysfunction in PCOS.////////////////// Runx3 transcription factor regulates ovarian functions and ovulation in female mice. Ojima F et al. (2016) We previously demonstrated that the Runx3 transcription factor is expressed in the hypothalami, pituitaries, and ovaries of mice, and that Runx3 knockout (Runx3(-/-)) mice are anovulatory and their uteri are atrophic. Runx3 mRNA expression was detected in the granulosa cells of ovarian follicles, and in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC). In the present study, we examined the effects of Runx3 knockout on the gene expression of enzymes associated with steroidogenesis. We found decreased Cyp11a1 mRNA expression in Runx3(-/-) mouse ovaries compared with that in wild-type (wt) mouse ovaries at the age of 8 weeks. In situ hybridization analysis showed that the percentages of Cyp11a1 mRNA-expressing theca cells in follicles of Runx3(-/-) mice were decreased compared with those of wt mice. In accord with the alterations in Runx3(-/-) mouse ovaries, Kiss1 mRNA levels in ARC were increased, whereas mRNA levels of kisspeptin in AVPV were decreased, and gonadotropin-releasing hormone in the preoptic area and follicle-stimulating hormone β subunit gene were increased in Runx3(-/-) mice. Following an ovarian transplantation experiment between Runx3(-/-) mice and wt mice, corpora lutea were observed when ovaries from Runx3(-/-) mice were transplanted into wt mice, but not when those from wt mice were transplanted into Runx3(-/-) mice, suggesting that Runx3 in the hypothalamo-pituitary system may drive gonadotropin release to induce ovulation in the ovary. These findings indicate that Runx3 plays a crucial role in the hypothalamo-pituitary-gonadal axis.//////////////////
Follicle stages
Comment
Phenotypes
PCO (polycystic ovarian syndrome)
Mutations
3 mutations
Species: mouse
Mutation name: None
type: targeted overexpression fertility: subfertile Comment: Misregulated Progesterone Secretion and Impaired Pregnancy in Cyp11a1 Transgenic Mice. Chien Y 2013 et al.
Normal pregnancy is supported by increased levels of progesterone (P4), which is secreted from ovarian luteal cells via enzymatic steps catalyzed by P450scc (CYP11A1) and HSD3B. The development and maintenance of the corpora lutea during pregnancy, however, are less well understood. Here we use Cyp11a1 transgenic mice to delineate the steps of luteal cell differentiation during pregnancy. Cyp11a1 in a bacterial artificial chromosome was injected into mouse embryos to generate transgenic mice with transgene expression that recapitulates the endogenous Cyp11a1 expression. Cyp11a1 transgenic females displayed reduced pregnancy rate, impaired implantation and placentation, and decreased litter size in utero, although they produced comparable numbers of blastocysts. The differentiation of transgenic luteal cells was delayed during early pregnancy as shown by the delayed activation of genes involved in steroidogenesis and cholesterol availability. Luteal cell mitochondria were elongated and their numbers were reduced similar to morphology and numbers observed in granulosa cells. Transgenic luteal cells accumulated lipid droplets and secreted less progesterone during early pregnancy. The progesterone level returned to normal on Gestation Day 9, but was not properly withdrawn at term, leading to delayed still birth. P4 supplement rescued the implantation rates but not the ovarian defects. Thus overexpression of Cyp11a1 disrupts normal development of the corpus luteum, leading to progesterone insufficiency during early pregnancy. The misregulation of the progesterone production in Cyp11a1 transgenic mice during pregnancy results in aberrant implantation, anomalous placentation, and delayed parturition.
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Species: human
Mutation name: None
type: naturally occurring fertility: subfertile Comment: CYP11A1 microsatellite (tttta)n polymorphism in PCOS women from South India. Reddy KR 2014 et al.
BACKGROUND
Polycystic ovary syndrome (PCOS) is a condition with central feature of hyperandrogensism that affects 5-12% of women worldwide. P450sec the cholesterol side chain cleavage enzyme encoded by CYP11A1 gene is instrumental in the synthesis of sex hormones. A promoter pentanucleotide repeat (tttta)n polymorphism of this gene is reported to be associated with several hormone related diseases including PCOS. Here we aimed to examine the involvement of CYP11A1 polymorphism with PCOS susceptibility in a case-control study conducted among South Indian women.
METHODS
A total of 542 subjects comprised of 267 PCOS patients and 275 controls were recruited. DNA was extracted from blood and CYP11A1 (tttta)n polymorphism was genotyped by PCR-PAGE.
RESULTS
Fifteen different alleles ranging between 2-16 repeats were identified in the studied group and the most frequent allele observed in controls was of 8 repeats. The presence of >8 repeat allele was common in patients (64% vs. 38%) and showed a three-fold risk for PCOS susceptibility than controls (OR?=?2.93; p?
Species: human
Mutation name: Polycystic ovarian syndrome
type: naturally occurring fertility: infertile - ovarian defect Comment: An association study of 97 consecutively identified Europids with PCOS and matched controls demonstrates significant allelic association of a CYP11a 5' UTR pentanucleotide repeat polymorphism with hirsute PCOS subjects (p = 0.03). A strong association was also found between alleles of this polymorphism and total serum testosterone levels in both affected and unaffected individuals (p = 0.002). The data demonstrate that variation in CYP11a may play an important role in the aetiology of hyperandrogenaemia which is a common characteristic of polycystic ovary syndrome (Gharani et al., 1997).////Common polymorphisms in the CYP1A1 and CYP11A1 genes and polycystic ovary syndrome risk: a meta-analysis and meta-regression. Shen W et al. (2015) Increasing scientific evidences suggest that common polymorphisms in the CYP1A1 and CYP11A1 genes may contribute to the development and progression of polycystic ovary syndrome (PCOS), but many existing studies have yielded inconclusive results. The aim of this study was to perform a meta-analysis of published studies on the associations between common polymorphisms in the CYP1A1 and CYP11A1 genes and susceptibility to PCOS. An extensive literature search for relevant studies was conducted on PubMed, Embase, Web of Science, Cochrane Library, and CBM databases from their inception through 1 June, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude risk ratio (RR) with 95% confidence interval was calculated. Thirteen case-control studies were included in this meta-analysis with a total of 1,571 PCOS cases and 1,918 healthy controls. Our meta-analysis revealed that CYP1A1 MspI (rs4646903 T > C) polymorphism may increase the risk of PCOS, especially among Caucasian populations. Furthermore, CYP11A1 microsatellite [TTTA]n repeat polymorphism also showed significant associations with increased risk of PCOS among Caucasian populations. However, there was no statistically significant association between CYP1A1 Ile462Val (rs1048943 A > G) polymorphism and PCOS risk. Our meta-analysis suggests that CYP1A1 MspI and CYP11A1 microsatellite [TTTA]n repeat polymorphisms may contribute to increasing susceptibility to PCOS among Caucasian populations. Detection of common polymorphisms in the CYP1A1 and CYP11A1 genes might be promising biomarkers for the diagnosis and prognosis of PCOS.//////////////////