Association of CYP17A1 gene -34T/C polymorphism with polycystic ovary syndrome in Han Chinese population

The Association of CYP17A1, CYP19A1, and SHBG Gene Polymorphisms in Polycystic Ovary Syndrome Susceptibility: A Systematic Review and Meta-Analysis

Objective: To elucidate the relationship between CYP17A1/CYP19A1/SHBG gene polymorphisms and PCOS susceptibility.

Methods: We searched multiple databases from inception to December 2020 and meta analysis was conducted to elucidate the relationship between gene polymorphisms and PCOS risk.

Results: 26 studies were included, comprising 4860 PCOS and 4043 controls. CYP17A1 rs743572 polymorphisms were found to be negatively associated with PCOS risk under dominant model (p = 0.017, OR = 0.83, 95%CI 0.72–0.97, I² = 74.80%, P_{heterogeneity} = 0.000) in the general population while neither CYP19A1 rs2414096 polymorphisms (p = 0.578, OR = 0.87, 95%CI 0.54–1.41, I² = 95.90%, P_{heterogeneity} = 0.000) nor SHBG rs6529 polymorphisms (p = 0.752, OR = 0.99, 95%CI 0.94–1.05, I² = 60.90%, P_{heterogeneity} = 0.012) was associated with PCOS susceptibility under dominant model in the general population.

Conclusion: CYP17A1 rs7435721 polymorphisms might be protective factors against PCOS in general populations.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#myprospero, identifier CRD4202122640.

Association Between the Polymorphism of Steroid Hormone Metabolism Genes and High-Altitude Pulmonary Edema in the Chinese Han Population

Purpose

Steroid hormone metabolism plays an essential role in high-altitude pulmonary edema (HAPE) progression. This study aimed to investigate the association between polymorphism in seven steroid hormone metabolism genes (STAR, HSD3B1, HSD3B2, CYP17A1, CYP21A2, CYP11B1, and CYP11B2) and HAPE susceptibility among Han Chinese.

Patients and Methods

A total of 41 tagSNPs in the seven genes were genotyped using Sequenom MassARRAY SNP assays from 169 HAPE patients (HAPE-p) and 309 matched Han Chinese individuals resistant to HAPE (HAPE-r). The genotypic and allele frequencies, odds ratios (ORs), and 95% confidence intervals (95% CIs) were calculated.

Results

Four SNPs, including the allele C of rs6203 (p = 0.034, OR [95% CI] = 1.344 [1.022−1.767]) in HSD3B1, allele G of rs3740397 (p = 0.044, OR [95% CI] = 1.314 [1.007−1.714]) and allele C of rs10786712 (p = 0.039, OR [95% CI] = 0.751 [0.572−0.986]) in CYP17A1, and allele T of rs6402 (p = 0.006, OR [95% CI] = 0.504 [0.306−0.830]) in CYP11B1, were significantly associated with HAPE. The distribution of the genotypes of these SNPs also significantly differed between the HAPE-p and HAPE-r groups. Moreover, six haplotypes (the linkage disequilibrium block including rs10883783, rs4919686, rs3740397, rs3824755, and rs10786712) of CYP17A1 were also significantly associated with HAPE.

Conclusion

The four SNPs located in HSD3B1 (rs6203), CYP17A1 (rs3740397 and rs10786712), and CYP11B1 (rs6402) and the six haplotypes of CYP17A1 are likely to have an effect on HAPE.

CYP17 T/C (rs74357) gene polymorphism contributes to polycystic ovary syndrome susceptibility: evidence from a meta-analysis

The cytochrome P450 family 17 (CYP17) is associated with hyperandrogenism in women, and the association between CYP17 gene polymorphism and the risk of polycystic ovary syndrome (PCOS) is not definitive. In order to determine whether the CYP17 T/C (rs74357) gene polymorphism is an exposure risk for PCOS, a comprehensive meta-analysis summarizing 19 studies was performed. The pooled odds ratio (OR) and the corresponding 95% CI were measured under five genetic models, and the stratified analyses by ethnicity, Hardy-Weinberg equilibrium, testosterone levels and BMI in controls were carried out to identify the causes of substantial heterogeneity. The overall results validated that the CYP17 T/C (rs74357) gene polymorphism was significantly associated with PCOS risk in four genetic models. Moreover, the outcomes of subgroup analysis by ethnicity indicated that the frequencies of the C allele of CYP17 T/C (rs74357) polymorphism were markedly higher in women from Asia than in Caucasians (T vs C: OR 0.85, 95% CI = 0.74-0.99, P < 0.05). Therefore, these findings suggested that the CYP17 T/C (rs74357) gene polymorphism played an indispensable part in increasing the susceptibility of PCOS when carrying the C allele, which proposed that the polymorphism of the CYP17 gene may be a predictive factor for the risk of PCOS or an important pathway in PCOS-associated metabolic and hormonal dysregulation.

The single-nucleotide polymorphism rs743572 of CYP17A1 shows significant association with polycystic ovary syndrome: a meta-analysis

Polycystic ovary syndrome (PCOS) is a multifactorial reproductive and endocrine disease, believed to be caused by aberrant steroid biosynthesis pathways involving cytochrome P450, 17α-hydroxylase (CYP17A1). This meta-analysis aimed to evaluate the association between CYP17A1 polymorphism rs743572 and PCOS risk. Studies on the CYP17A1 gene were retrieved by searching PubMed, Embase and Web of Science and statistical analyses were performed by STATA software. Fifteen eligible studies were included, dated from January 1994 to 19 November 2020, involving 2277 patients with PCOS and 1913 control individuals. Overall, the results showed that the rs743572 T>C mutation was most likely to be associated with PCOS risk under the recessive model, which was further confirmed by heterogeneity analysis and publication bias detection (CC versus CT + TT, odds ratio [OR] 1.24, 95% confidence interval [CI] 1.02-1.50, P = 0.028, I² = 35.9%). Moreover, subgroup analysis by ethnicity demonstrated that Caucasian but not Asian women carrying the CC genotype of rs743572 had an elevated risk of PCOS (CC versus CT + TT, OR 1.45, 95% CI 1.03-2.06, P = 0.035, I² = 15.10%, six studies). In conclusion, rs743572 is highly likely to be a risk factor for PCOS, and the mutant genotype CC may increase susceptibility to PCOS in Caucasians rather than Asians.

Genetic polymorphisms associated with polycystic ovary syndrome among Iranian women

Polycystic ovary syndrome (PCOS) involves abnormalities in ovarian, reproductive, and metabolic systems. Genetic polymorphisms associated with individual differences and variations might be related to complex disorders with unknown causes, including PCOS. Several leading genetic markers with known cellular functions have been identified among Iranian women presenting with PCOS. In particular, the existing evidence shows a significant relationship between PCOS and the following genetic polymorphisms: rs2275913 (interleukin-17A), rs9927163 (interleukin-32), Pro12Ala (peroxisome proliferator-activated receptor-γ), rs17173608 (chemerin), rs2236242 (vaspin), ApaI (vitamin D receptor), and rs7895833 (sirtuin 1). In addition, a higher risk of PCOS is associated with the rs2910164 (microRNA 146a), rs2241766 (adiponectin), -34 T/C (cytochrome 17), and rs1800682 (Fas) polymorphisms. Furthermore, protective effects against PCOS have been reported for the A4223C polymorphism of adenosine deaminase 1. Overall, the available data indicate that Iranian women with PCOS have a higher prevalence of polymorphisms in inflammation- and metabolism-related genes, but not in insulin-related genes. More extensive studies are needed to identify the ethnicity-related genetic associations in PCOS.

Zebrafish as a model for studying ovarian development: Recent advances from targeted gene knockout studies

Ovarian development is a complex process controlled by precise coordination of multiple factors. The targeted gene knockout technique is a powerful tool to study the functions of these factors. The successful application of this technique in mice in the past three decades has significantly enhanced our understanding on the molecular mechanism of ovarian development. Recently, with the advent of genome editing techniques, targeted gene knockout research can be carried out in many species. Zebrafish has emerged as an excellent model system to study the control of ovarian development. Dozens of genes related to ovarian development have been knocked out in zebrafish in recent years. Much new information and perspectives on the molecular mechanism of ovarian development have been obtained from these mutant zebrafish. Some findings have challenged conventional views. Several genes have been identified for the first time in vertebrates to control ovarian development. Focusing on ovarian development, the purpose of this review is to briefly summarize recent findings using these gene knockout zebrafish models, and compare these findings with mammalian models. These established mutants and rapid development of gene knockout techniques have prompted zebrafish as an ideal animal model for studying ovarian development.

Identifying genes associated with the development of human polycystic ovary syndrome

The pathophysiology of polycystic ovary syndrome (PCOS) is confusing until today as it is a multifactorial endocrine disorder. It is presented with altered gonadotropin levels, bulky multi-follicular ovaries, infertility, and obesity. This complex pathophysiology is linked with insulin resistance and hyperandrogenism. Hyperandrogenemia significantly contributes towards cosmetic anomalies including hirsutism, acne, and alopecia in the PCOS women. The preexisting insulin resistance in women with PCOS is likely to aggravate the increased levels of androgen. The review findings have shown that in the steroidogenic pathway, ovarian steroidogenesis patterns classify mainly towards the hypertrophy of theca cells along with alteration in the expression of key enzymes. The association of polymorphisms in genes encoding the process of an intricate cascade of steroidogenesis is delineated. The emergence of an unanimously accepted genetic marker for susceptible PCOS was affected based on inconsistent findings. The present study has provided a comprehensive summary of the impact of polymorphisms among the common androgen-related genes to govern the genetic predisposition.

The CYP17 MSP AI (T-34C) and CYP19A1 (Trp39Arg) variants in polycystic ovary syndrome: A case-control study

Background

Polycystic ovary syndrome (PCOS) is a common and chronic disorder of endocrine glands where genetic factors play a major role in the susceptibility to the disease. The cytochrome (CYP) 17 enzyme is essential for androgens biosynthesis. Also, the CYP19 enzyme converts the androgens to the aromatic estrogens.

Objective

We aimed to investigate the association of CYP 17 MSP AI (T-34C) and CYP 19A1 (Trp39Arg) variants with the pathogenesis of PCOS in a population from Western Iran with Kurdish ethnic background.

Materials and Methods

The present case-control study consisted of 50 patients with PCOS and 109 controls. The CYP17 T-34C and CYP19A1 (Trp39Arg) polymorphisms were identified by polymerase chain reaction-restriction fragment length polymorphism. The serum lipid and lipoprotein profile were detected by the Bionic Diagnostic Kits. Estradiol, dehydroepiandrosterone (DHEA), and sex hormone-binding globulin (SHBG) levels were measured using the chemiluminescent method.

Results

The serum levels of estradiol and SHBG in PCOS patients were lower than controls (p < 0.001 and p = 0.06, respectively). However, the level of DHEA was higher (p = 0.01) in patients compared to controls. The higher frequency of CYP17 TC genotype in patients (30%) compared to controls (15.6%) was associated with 2.31-fold susceptibility to PCOS (p = 0.038). The frequency of CYP19 TC genotype was 6.4% in controls and 10% in patients (p = 0.42).

Conclusion

The present study suggests that CYP17 TC genotype could be associated with the risk of PCOS. Also, the study indicated the sex steroid hormones level alteration and the lower level of SHBG in PCOS patients compared to healthy individuals.

Polycystic ovary syndrome (PCOS) and genetic predisposition: A review article

Polycystic ovary syndrome (PCOS) is a heterogeneous condition which is related to an endocrine reproductive disorder of females. It affects females of 18-44 age. The persistent hormonal disbalance leads to the complexities such as numerous cysts, an irregular menstrual cycle that ultimately leads to infertility among females. Many candidate genes have been identified to be one of the causes of PCOS. Different studies have been carried out to find the genetic correlation of PCOS. It is essential to carry out such studies that identify the clear cause of PCOS and its genetic association and hormonal disbalance. This review has highlighted different genes and their correlation with PCOS that leads to hormonal disbalance. Yet not in-depth but an attempt to study the genetic predisposition of PCOS.

Oxidative stress increases the 17,20-lyase-catalyzing activity of adrenal P450c17 through p38α in the development of hyperandrogenism

Unexplained hyperandrogenic oligoanovulation is a main feature of polycystic ovary syndrome (PCOS). P450c17 phosphorylation selectively increases 17,20-lyase activity and androgen biosynthesis but minimally affects 17α-hydroxylase. Studies have recently identified mitogen-activated protein kinase 14 (MAPK14, p38α) as the kinase responsible for enhancing 17,20-lyase activity through P450c17 phosphorylation. We investigated whether oxidant-induced oxidative stress increases 17,20-lyase activity through oxidant-sensitive p38α signaling pathways. NCI-H295R adrenal cells were treated with three oxidants, palmitate, H₂O₂ and 4-hydroxy-2-nonenal (HNE), to simulate the excessive oxidative stress of PCOS. Oxidant exposure significantly induced dehydroepiandrosterone production and increased p38α phosphorylation and activation, but the effect on 17α-hydroxyprogesterone production was far less clear. None of the treatments altered the expression of P450c17 or its necessary factors POR and b5. LC-MS/MS revealed increased DHEA production in NCI-H295R cells. Both p38α inhibition and siRNA-mediated silencing attenuated H₂O₂- or 0.45-0.75 mM PA-mediated augmentation of DHEA production with relatively stable 17OHP levels, indicating that activated p38α mediates oxidative stress-induced 17,20-lyase activation and androgen synthesis stimulation, which may underlie hyperandrogenism in PCOS.

Pathophysiological mechanisms of gonadotropins- and steroid hormones-related genes in etiology of polycystic ovary syndrome

OBJECTIVES

Polycystic ovary syndrome (PCOS) is an endocrinopathy in women, which, unlike its impact on fertility and health of women, there is no clear understanding about the causal mechanisms of this pathogenesis. The aim of this review paper is to investigate the pathophysiological pathways affecting the PCOS etiology, based on functions of gonadotropins- and steroid hormones-related genes.

MATERIALS AND METHODS

Due to different hormonal and metabolic signs of this complex disorder, different hypotheses are mentioned about etiology of this syndrome. Because of the heterogeneity of the reasons given for this syndrome and the spread of the effective genes in its pathophysiology, most of genes affected by sex-related hormonal imbalances are examined for discriminative diagnosis. For this purpose, published articles and reviews dealing with genetic evaluation of PCOS in women in peer-reviewed journals in PubMed and Google Scholar databases were included in this review.

RESULTS

In previous studies, it has been well demonstrated that PCOS in some individuals have a genetic origin. Pathophysiological functions of genes are primarily responsible for the synthesis of proteins that have role in PCOS before hyperandrogenism including GnRHR, FSHβ, FSHR, LHCGR, CYP19A1, HSD17B, AR and SHBG, and their effects in PCOS of human have been confirmed.

CONCLUSION

Hormonal imbalances are the first reason mentioned in PCOS etiology, and usually characterized with menstrual irregularities in PCOS women. Hyperandrogenism and gonadotropin secretion disorders are shown in PCOS condition, which are related to steroidogenesis pathways and hypothalamic-pituitary-ovarian axis disturbances, respectively.

Genetic Variants Associated with Hyperandrogenemia in PCOS Pathophysiology

Polycystic ovary syndrome is a multifactorial endocrine disorder whose pathophysiology baffles many researchers till today. This syndrome is typically characterized by anovulatory cycles and infertility, altered gonadotropin levels, obesity, and bulky multifollicular ovaries on ultrasound. Hyperandrogenism and insulin resistance are hallmark features of its complex pathophysiology. Hyperandrogenemia is a salient feature of PCOS and a major contributor to cosmetic anomalies including hirsutism, acne, and male pattern alopecia in affected women. Increased androgen levels may be intrinsic or aggravated by preexisting insulin resistance in women with PCOS. Studies have reported augmented ovarian steroidogenesis patterns attributed mainly to theca cell hypertrophy and altered expression of key enzymes in the steroidogenic pathway. Candidate gene studies have been performed in order to delineate the association of polymorphisms in genes, which encode enzymes in the intricate cascade of steroidogenesis or modulate the levels and action of circulating androgens, with risk of PCOS development and its related traits. However, inconsistent findings have impacted the emergence of a unanimously accepted genetic marker for PCOS susceptibility. In the current review, we have summarized the influence of polymorphisms in important androgen related genes in governing genetic predisposition to PCOS and its related metabolic and reproductive traits.

Association between CYP17A1 rs3824755 and rs743572 gene polymorphisms and Alzheimer's disease in the Chinese Han population

The CYP17A1 gene encodes cytochrome P450c17α, an enzyme that catalyzes the formation of sex hormones, which have been linked to the pathogenesis of Alzheimer's disease (AD). An association between the CYP17A1 rs743572 single nucleotide polymorphism (SNP) and AD has been reported; however, the findings are controversial. In the present study, we investigated the association between rs743572 and another SNP, rs3824755, and AD risk in a Chinese Han population (n=207 patients and 239 controls), and their interaction with the apolipoprotein E (APOE) e4 allele. We found that the C allele and GC+CC genotypes of rs3824755 conferred protection against AD only in APOE e4 carriers. Both rs3824755 and rs743572 polymorphisms showed interactions with APOE e4. The C allele and GC+CC genotypes of rs3824755 acted as protective factors that decreased the risk of APOE e4 in AD. The CYP17A1 rs743572G allele and AG+GG genotypes were found to be potential risk factors that act synergetically with APOE e4. Moreover, the CA and GG haplotypes were protective and conferred a slight risk, respectively, in APOE e4 carriers. These results indicate that CYP17A1 rs3824755 and rs743572 are associated with AD in the Chinese Han population and act in combination with APOE e4.