Nonreplication of the type 5 17beta-hydroxysteroid dehydrogenase gene association with polycystic ovary syndrome

An investigation of steroid biosynthesis pathway genes in women with polycystic ovary syndrome

Background:

Polycystic ovary syndrome (PCOS) is a common endocrinopathy whose heterogeneous genetic basis results in a variable clinical presentation. One of the main clinical features of PCOS is hyperandrogenism which occurs due to dysregulation of ovarian and adrenal steroidogenesis.

Aims:

This study aimed to investigate potentially pathogenic variants in steroidogenic genes associated with PCOS.

Settings and Design:

This was a hospital-based observational study.

Materials and Methods:

We recruited 51 women who presented with PCOS. Fasting blood samples were drawn from the participants and their whole-exome sequencing analysis was carried out to look for pathogenic variants involved in steroidogenic pathways. The variants were predicted for their probable deleterious effects on proteins through in silico prediction tools. We evaluated the variants with respect to the hormonal characteristics and clinical outcomes of the patients.

Statistical Analysis Used:

All variables were analysed using GraphPad Prism 8. Kruskal–Wallis t-test and Fisher's exact test were used to compare clinical parameters and frequency differences among PCOS patients with and without variants.

Results:

The data presented here reveal eight heterozygous exonic variants, namely CYP21A2 (p.Ala392Thr, p.Gln319Ter and p.I143N), steroidogenic acute regulatory (p.Arg53 Leu), AKR1C3 (p.Phe205Val), P450 oxidoreductase (p.Val334Ile and p.Val251Met) and HSD17B6 (p.Gly40Ser), of which three were pathogenic, and four variants of uncertain significance in 8 out of 51 patients (15.68%). The identified variants were predicted to cause protein destabilisation, thus likely contributing to the pathogenesis of PCOS. Some of the variants showed significant differences between PCOS patients and population database (P < 0.05).

Conclusion:

The results of this study add to the mutational spectrum of steroidogenic genes and their association with PCOS.

Association of genetic polymorphisms with local steroid metabolism in human benign breasts

PURPOSE

Although alterations of concentrations in circulating steroids have been linked to single nucleotide polymorphisms (SNPs) of steroidogenic enzymes, we hypothesized that SNPs of such enzymes located within the breast affect local steroid concentrations more than products of such SNPs absorbed from the circulation.

METHODS

Steroids (estradiol, estrone, testosterone, androstenedione, DHEA, DHEA sulfate, progesterone) in nipple aspirate fluid (NAF) were purified by HPLC and they along with serum steroids were quantified by immunoassays. Polymorphisms of the transporter SLCO2B1 and enzymes HSD3B1, CYP19A1, HSD17B12, AKR1C3, CYP1B1, and SRD5A1 were measured in white blood cell DNA.

RESULTS

Steroid concentrations in NAF of subjects with homozygous minor genotypes differed from those with heterozygotes, i.e., SLCO2B1 (rs2851069) decreased DHEAS (p = 0.04), HSD17B12 (rs11555762) increased estradiol (p < 0.004), and CYP1B1 (rs1056836) decreased estradiol (p = 0.017) and increased progesterone (p = 0.05). Also, in serum, CYP19A1 (rs10046 and rs700518) both decreased testosterone (p = 0.02) and SRD5A1 increased androstenedione (p = 0.006). Steroids in subjects with major homozygotes did not differ from those with heterozygotes indicating recessive characteristics.

CONCLUSIONS

In the breast, SNPs were associated with decreased uptake of DHEAS (SLCO2B1), increased estradiol concentrations through increased oxidoreductase activity (HSD17B12), or decreased estradiol concentrations by presumed formation of 4-hydroxyestradiol (CYP1B1). CYP19A1 was associated with decreased testosterone concentrations in serum but had no significant effect on estrogen or androgen concentrations within the breast. The hormone differences observed in NAF were not usually evident in serum, indicating the importance of assessing the effect of these SNPs within the breast.

The role of polymorphism in various potential genes on polycystic ovary syndrome susceptibility and pathogenesis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathies affecting the early reproductive age in women, whose pathophysiology perplexes many researchers till today. This syndrome is classically categorized by hyperandrogenism and/or hyperandrogenemia, menstrual and ovulatory dysfunction, bulky multi follicular ovaries on Ultrasonography (USG), and metabolic abnormalities such as hyperinsulinemia, dyslipidemia, obesity. The etiopathogenesis of PCOS is not fully elucidated, but it seems that the hypothalamus-pituitary-ovarian axis, ovarian, and/or adrenal androgen secretion may contribute to developing the syndrome. Infertility and poor reproductive health in women's lives are highly associated with elevated levels of androgens. Studies with ovarian theca cells taken from PCOS women have demonstrated increased androgen production due to augmented ovarian steroidogenesis attributed to mainly altered expression of critical enzymes (Cytochrome P450 enzymes: CYP17, CYP21, CYP19, CYP11A) in the steroid hormone biosynthesis pathway. Despite the heterogeneity of PCOS, candidate gene studies are the widely used technique to delineate the genetic variants and analyze for the correlation of androgen biosynthesis pathway and those affecting the secretion or action of insulin with PCOS etiology. Linkage and association studies have predicted the relationship between genetic variants and PCOS risk among families or populations. Several genes have been proposed as playing a role in the etiopathogenesis of PCOS, and the presence of mutations and/or polymorphisms has been discovered, which suggests that PCOS has a vital heritable component. The following review summarizes the influence of polymorphisms in crucial genes of the steroidogenesis pathway leading to intraovarian hyperandrogenism which can result in PCOS.

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.

Differential activity of the corticosteroidogenic enzymes in normal cycling women and women with polycystic ovary syndrome

The phenotypic complex of patients with definitive diagnosis of polycystic ovary syndrome may include patients with normal and high serum androgen levels. Patients with hyperandrogenemia seem to present higher risk of changes to the glucose and lipid metabolism and, eventually, of earlier development of cardiovascular diseases than normoandrogenemic patients or healthy women. From a laboratory and clinical point of view, it is important to check androgen levels in patients with polycystic ovary syndrome. The identification of partial insufficiency of a given corticosteroidogenic enzyme is also relevant to understand the physiopathology of androgen increase in polycystic ovary syndrome. Therefore, the present review analyzes the functions of the different enzymes involved in the ovary and adrenal steroidogenesis in normal cycling women and in patients with polycystic ovary syndrome. In addition, it emphasizes appropriate reason for investigating eventual enzyme deficiency to provide rationale for prescription and follow-up of women with polycystic ovary syndrome.

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 analysis between the polymorphisms of HSD17B5 and HSD17B6 and risk of polycystic ovary syndrome in Chinese population

OBJECTIVE

To assess whether single nucleotide polymorphisms of HSD17B5 (AKR1C3) (rs1937845 and rs12529) and HSD17B6 (rs898611) are associated with polycystic ovary syndrome (PCOS) in a Chinese population.

DESIGN

A case-control study was conducted to investigate the relation between HSD17B5 and HSD17B6 polymorphisms and PCOS.

METHODS

In this study, 335 patients with PCOS and 354 controls were recruited. The genotypes of HSD17B5 (rs1937845 and rs12529) and HSD17B6 (rs898611) were detected by the TaqMan method.

RESULTS AND CONCLUSIONS

We found that the genotypic frequencies of the rs1937845 polymorphism were different in subjects with PCOS compared with control, with the CT genotype being more commonly found in patients with PCOS than in controls (P=0.005). We observed a significantly 1.74-fold higher risk of CT genotype in the polymorphism rs1937845 in women with PCOS vs the control group (adjusted odds ratio (OR), 1.74; 95% CI=1.19-2.54; P=0.005). A similar, significant 1.47-fold higher risk (adjusted OR, 1.47; 95% CI=1.07-2.03; P=0.018) was demonstrated for T allele of polymorphism rs1937845 associated with PCOS. In patients with PCOS, the rs12529 (G>C) and rs1937845 (C>T) polymorphisms were strongly associated with the high level of testosterone. The TT carriers of polymorphism rs1937845 had a significantly increased homeostatic model assessment-B% (HOMA-B%) (P=0.045) and that might be associated with the high risk of insulin resistance. However, no significant difference was found in genotype or allele distributions of the polymorphisms rs12529 of HSD17B5 and rs898611 of HSD17B6 between patients with PCOS and controls. Additionally, the two polymorphisms of HSD17B5 are associated with hyperandrogenemia in patients with PCOS. In conclusion, our findings showed a significant statistical association between HSD17B5 rs1937845 and PCOS risk in Chinese women. The CT genotype and T allele frequency are influenced significantly to a higher extent in patients with PCOS than controls. Further studies are needed to confirm the results and find out the exact molecular mechanism of the polymorphism on the risk of hyperandrogenemia and PCOS.

Evidence for gonadotrophin secretory and steroidogenic abnormalities in brothers of women with polycystic ovary syndrome

STUDY QUESTION

Are there abnormalities in gonadotrophin secretion, adrenal steroidogenesis and/or testicular steroidogenesis in brothers of women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Brothers of women with PCOS have increased gonadotrophin responses to gonadotrophin releasing hormone (GnRH) agonist stimulation and alterations in adrenal and gonadal steroidogenesis.

WHAT IS KNOWN ALREADY

PCOS is a complex genetic disease. Male as well as female first-degree relatives have reproductive features of the syndrome. We previously reported that brothers of affected women have elevated circulating dehydroepiandrosterone sulfate levels.

STUDY DESIGN, SIZE, DURATION

This was a case-control study performed in 29 non-Hispanic white brothers of 22 women with PCOS and 18 control men.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PCOS brothers and control men were of comparable age, weight and ethnicity. Adrenocorticotrophic hormone (ACTH) and GnRH agonist stimulation tests were performed. Gonadotrophin responses to GnRH agonist as well as changes in precursor-product steroid pairs (delta, Δ) across steroidogenic pathways in response to ACTH and GnRH agonist were examined.

MAIN RESULTS AND THE ROLE OF CHANCE

Basal total (T) levels did not differ, but dehydroepiandrosterone (DHEA) levels (0.13 ± 0.08 brothers versus 0.22 ± 0.09 controls, nmol/l, P = 0.03) were lower in brothers compared with control men. ACTH-stimulated Δ17-hydroxypregnenolone (17Preg)/Δ17-hydroxyprogesterone (17Prog) (7.8 ± 24.2 brothers versus 18.9 ± 21.3 controls, P = 0.04) and ΔDHEA/Δandrostenedione (AD) (0.10 ± 0.05 brothers versus 0.14 ± 0.08 controls, P = 0.04) were lower in brothers than in the controls. GnRH agonist-stimulated Δ17Prog/ΔAD (0.28 ± 8.47 brothers versus 4.79 ± 10.28 controls, P = 0.003) was decreased and luteinizing hormone (38.6 ± 20.6 brothers versus 26.0 ± 9.8 controls, IU/l, P = 0.02), follicle-stimulating hormone (10.2 ± 7.5 brothers versus 4.8 ± 4.1 controls, IU/l P = 0.002), AD (1.7 ± 1.4 brothers versus 0.9 ± 1.5 controls, nmol/l, P = 0.02) and ΔAD/ΔT (0.16 ± 0.14 brothers versus 0.08 ± 0.12 controls, P = 0.005) responses were increased in brothers compared with controls.

LIMITATIONS, REASONS FOR CAUTION

The modest sample size may have limited our ability to observe other possible differences in steroidogenesis between PCOS brothers and control men.

WIDER IMPLICATIONS OF THE FINDINGS

Decreased ACTH-stimulated Δ17Preg/Δ17Prog and ΔDHEA/ΔAD responses suggested increased adrenal 3β-hydroxysteroid dehydrogenase activity in the brothers. Decreased Δ17Prog/ΔAD and increased ΔAD/ΔT responses to GnRH agonist stimulation suggested increased gonadal 17,20-lyase and decreased gonadal 17β-hydroxysteroid dehydrogenase activity in the brothers. Increased LH and FSH responses to GnRH agonist stimulation suggested neuroendocrine alterations in the regulation of gonadotrophin secretion similar to those in their proband sisters. These changes in PCOS brothers may reflect the impact of PCOS susceptibility genes and/or programming effects of the intrauterine environment.

STUDY FUNDING/COMPETING INTERESTS

This research was supported by P50 HD044405 (A.D.), K12 HD055884 (L.C.T.), U54 HD034449 (A.D., R.S.L.) from the National Institute of Child Health and Development. Some hormone assays were performed at the University of Virginia Center for Research in Reproduction Ligand Assay and Analysis Core that is supported by U54 HD28934 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Partial support for some of the clinical studies was provided by UL1 RR025741 and UL1 TR000150 (Northwestern University Clinical and Translational Sciences Institute) from the National Center for Research Resources, National Institutes of Health, which is now the National Center for Advancing Translational Sciences. The authors have no conflict of interest to declare.

Basal and Regulatory Promoter Studies of the AKR1C3 Gene in Relation to Prostate Cancer

Background: Human 17β-hydroxysteroid dehydrogenase type 5 (17β-HSD5) formally known as aldo-keto reductase 1C3 (AKR1C3) play a major role in the formation and metabolism of androgens. The enzyme is highly expressed in the prostate gland and previous studies indicate that genetic variation in the AKR1C3 gene may influence the prostate volume and risk of prostate cancer. Aim: Here we aimed to further study the genetic regulation of AKR1C3 and its putative role in prostate cancer. Experiments: A previously identified promoter polymorphism (A>G, rs3763676) localized at −138 from the translational start site were studied in relation to prostate cancer in a Swedish population based case–control study including 176 patients diagnosed with prostate cancer and 161 controls. Moreover, we have studied the basal and androgen induced promoter activity of the AKR1C3 gene. Expression studies with AKR1C3 promoter reporter constructs were performed in HepG2 and DSL2 cells. Results: We found that carriers of the promoter A-allele had a borderline significant decreased risk of prostate cancer (OR = 0.59; 95% CI = 0.32–1.08). We also show that dihydrotestosterone (DHT) induced the promoter activity of the A-allele 2.2-fold (p = 0.048). Sp3 seem to play an important role in regulating the transcription activity of AKR1C3 and site-directed mutagenesis of a GC-box 78 base-pair upstream the ATG-site significantly inhibited the basal AKR1C3 promoter activity by 70%. Conclusion: These results further supports previous findings that the A>G promoter polymorphism may be functional and that AKR1C3 plays a critical role in prostate carcinogenesis. Our findings also show that the members of Sp family of transcription factors are important for the constitutive expression of AKR1C3 gene.

17-Hydroxysteroid dehydrogenase type 5 gene polymorphism (-71A/G HSD17B5 SNP) and treatment with oral contraceptive pills in PCOS women without metabolic comorbidities

We studied (1) the effects of oral contraceptive pills (OCPs) on hirsutism, hormonal and metabolic variables in 49 polycystic ovary syndrome patients without metabolic comorbidities and (2) the effect of 17-hydroxysteroid dehydrogenase type 5 gene polymorphism (-71A/G HSD17B5 SNP) on the response to OCP treatment. Mean age was 21.9 ± 6.5 years. Patients received monophasic OCP (20 μg ethinyl estradiol plus 75 μg gestodene), 21/28 days per cycle, during 6 months; 32 patients with severe hirsutism also received spironolactone 100 mg. The frequencies of HSD17B5 genotypes were: AA = 0.49 (55.1%), AG = 0.42 (30.6%) and GG = 0.09 (14.3%). After 6 months, body mass index and waist circumference remained unchanged regardless of the presence of allele G. A slight reduction (p < 0.05) was noted in systolic blood pressure (p < 0.05) and luteinizing hormone levels, whereas a slight increase (p < 0.05) was noted in lipids. Total testosterone and hirsutism score declined, while sex hormone binding globulin increased after OCP treatment (p < 0.05). None of these changes were associated with genotype. Insulin and homeostasis model assessment remained unchanged after treatment and did not vary according to the presence of allele G. OCP seems to ameliorate androgenic symptoms without compromising metabolic parameters. The -71A/G SNP of HSD17B5 gene did not contribute to the improvements observed.

The influence of obesity on androstenedione to testosterone ratio in women with polycystic ovary syndrome (PCOS) and hyperandrogenemia

The aim of the present study was to evaluate the impact of obesity and insulin resistance on testosterone formation from androstenedione and its contribution to biochemical hyperandrogenemia in all different phenotypic subgroups of PCOS patients. The case-control study included 1087 PCOS women and 206 regularly menstruating, ovulatory controls. The main clinical measurements included anthropometric and basal hormonal characteristics and evaluation of hyperandrogenic and insulin resistance-related features. The results were the following: In PCOS women with biochemical hyperandrogenemia, obesity significantly lowers serum A levels and increases T to A ratio. These findings were not present in PCOS women with clinical hypeandrogenemia and in normal ovulatory controls.

State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS)

PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy.

Replication of association of a novel insulin receptor gene polymorphism with polycystic ovary syndrome

OBJECTIVE

To evaluate association with polycystic ovary syndrome (PCOS) of 295 variants in 39 genes central to metabolic insulin signaling and glycogen synthase kinase 3β (GSK-3β) regulation, followed by replication efforts.

DESIGN

Case-control association study, with discovery and replication cohorts.

SETTING

Subjects were recruited from reproductive endocrinology clinics, and controls were recruited from communities surrounding the University of Alabama at Birmingham and Erasmus Medical Center, Rotterdam.

PATIENT(S)

A total of 273 cases with PCOS and 173 control subjects in the discovery cohort; and 526 cases and 3,585 control subjects in the replication cohort. All subjects were caucasian.

INTERVENTION(S)

Phenotypic and genotypic assessment.

MAIN OUTCOME MEASURE(S)

Detection of 295 single-nucleotide polymorphisms (SNPs), PCOS status.

RESULT(S)

Several SNPs were associated with PCOS in the discovery cohort. Four insulin receptor (INSR) SNPs and three insulin receptor substrate 2 (IRS2) SNPs associated with PCOS were genotyped in the replication cohort. One INSR SNP (rs2252673) replicated association with PCOS. The minor allele conferred increased odds of PCOS in both cohorts, independent of body mass index.

CONCLUSION(S)

A pathway-based tagging SNP approach allowed us to identify novel INSR SNPs associated with PCOS, one of which confirmed association in a large replication cohort.

Polycystic ovary syndrome: etiology, pathogenesis and diagnosis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age, with a prevalence of up to 10%. Various diagnostic criteria have been proposed, generally centered around the features of hyperandrogenism and/or hyperandrogenemia, oligo-ovulation and polycystic ovarian morphology. Insulin resistance is present in a majority of cases, with compensatory hyperinsulinemia contributing to hyperandrogenism via stimulation of ovarian androgen secretion and inhibition of hepatic sex hormone-binding globulin production. Adipose tissue dysfunction has been implicated as a contributor to the insulin resistance observed in PCOS. Environmental and genetic factors also have a role in the development of PCOS. The syndrome is associated with numerous morbidities, including infertility, obstetrical complications, type 2 diabetes mellitus, cardiovascular disease, and mood and eating disorders. Despite these morbidities, PCOS may be common in our society owing to evolutionary advantages of the syndrome in ancient times, including smaller family sizes, reduced exposure to childbirth-related mortality, increased muscle mass and greater capacity to store energy. The diagnosis of PCOS hinges on establishing key features while ruling out other hyperandrogenic or oligo-ovulatory disorders. Treatment is focused on the goals of ameliorating hyperandrogenic symptoms, inducing ovulation and preventing cardiometabolic complications.

Polymorphisms of the HSD17B6 and HSD17B5 genes in Chinese women with polycystic ovary syndrome

OBJECTIVES

To investigate the polymorphisms of the 17β-hydroxysteroid dehydrogenase type 5 and type 6 (HSD17B5 and HSD17B6) genes in Chinese women with polycystic ovary syndrome (PCOS).

METHODS

Two hundred twenty-two PCOS patients and 283 controls were studied. Menarche age was recorded. Body mass indices (BMI) were calculated. Blood samples were obtained for single nucleotide polymorphism (SNP) analyses and hormone measurements. Genotyping of HSD17B6 and HSD17B5 in cases and controls was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The SNP rs898611 of the HSD17B6 gene (TT, CT, CC) in women with PCOS (0.680, 0.270, 0.050, respectively) did not differ from those in controls (0.700, 0.258, 0.042, respectively), and the SNP rs3763676 of the HSD17B5 gene (AA, AG, GG) was rare in Chinese women. Total testosterone and other reproductive hormones, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), LH/FSH, and estradiol (E(2)), were also similar among the different genotypes of the HSD17B6 in the PCOS subjects and the controls, whereas BMI was different in the three genotypes of the HSD17B6 in PCOS subjects.

CONCLUSIONS

Our data suggest that there is no association of HSD17B6 and HSD17B5 variants with the occurrence of PCOS in the Chinese population, but the polymorphism of SNP rs898611 is associated with BMI in PCOS patients.

Independent confirmation of association between metabolic phenotypes of polycystic ovary syndrome and variation in the type 6 17beta-hydroxysteroid dehydrogenase gene

CONTEXT

Few candidate genes for polycystic ovary syndrome (PCOS) are widely agreed upon largely due to lack of replication. Type 6 17beta-hydroxysteroid dehydrogenase (HSD17B6) gene expression is increased in PCOS ovarian theca. Previous genetic study of HSD17B6 reported significant association of rs898611 with PCOS risk and metabolic phenotypes.

OBJECTIVE

Our objective was to replicate association between polymorphisms in HSD17B6 and PCOS in a well-characterized replication cohort.

DESIGN

We conducted a case-control association study.

SETTING

Subjects were recruited from reproductive endocrinology clinics; controls were recruited from the surrounding communities of the University of Alabama at Birmingham and Cedars-Sinai Medical Center in Los Angeles. Genotyping occurred at Cedars-Sinai Medical Center.

PARTICIPANTS

Participants included 335 White women with PCOS and 198 White controls.

MAIN MEASUREMENTS

We assessed HSD17B6 genotype, PCOS status, and metabolic traits.

RESULTS

The minor allele of rs898611 was not associated with PCOS; however, it was associated with increased body mass index (P = 0.031), increased fasting insulin (P = 0.008), decreased fasting glucose/insulin ratio (P = 0.038), and increased homeostasis model assessment of insulin resistance (HOMA-IR) (P = 0.021). rs10459247 and rs10876920 were associated with increased fasting insulin (P = 0.031 and 0.019, respectively), and rs10876920 was also associated with increased HOMA-IR (P = 0.046). Haplotype T-A-T-C was associated with reduced fasting insulin (P = 0.046), and haplotype C-A-C-T was associated with increased body mass index (P = 0.032).

CONCLUSIONS

Although we did not replicate association between PCOS and rs898611, we replicated associations of this variant and others in HSD17B6 with metabolic traits. These replication data suggest a role for HSD17B6 in PCOS. How HSD17B6, an enzyme involved in steroid metabolism, may influence BMI and insulin resistance in PCOS remains to be determined.

The role of genes in the polycystic ovary syndrome: predisposition and mechanisms

The polycystic ovary syndrome (PCOS), mainly characterized by clinical and/or biochemical hyperandrogenism, ovarian dysfunction and/or polycystic morphology as well as associated metabolic disorders, is the most common endocrine disorder in women of reproductive age. The familial clustering of PCOS cases and the accumulating evidence that the interaction between multiple genetic and environmental factors is necessary for the development of the syndrome, has triggered the conduct of genetic studies on PCOS. These studies have focused on many genetic polymorphisms, investigating their possible positive or negative correlation with the syndrome. The related genes can be grouped in four categories: those related with insulin resistance, those that interfere with the biosynthesis and the action of androgens, those that encode inflammatory cytokines and other candidate genes. Despite the progress that has been made in the elucidation of the genetic mechanisms of the PCOS, the genetic studies on the syndrome still face many obstacles and challenges. Further studies are needed, in order to shed new light in the pathogenesis of the syndrome, which will allow for new approaches in the diagnostics and therapeutics of PCOS.

KLF15 Is a transcriptional regulator of the human 17beta-hydroxysteroid dehydrogenase type 5 gene. A potential link between regulation of testosterone production and fat stores in women

CONTEXT

Kruppel-like factor 15 (KLF15) is a newly discovered transcription factor that plays an important role in glucose homeostasis and lipid accumulation in cells. We present evidence for KLF15 as a transcriptional regulator of the human 17beta-hydroxysteroid dehydrogenase type 5 gene (HSD17B5) and its potential role in the pathogenesis of hyperandrogenism.

OBJECTIVE

The aim was to investigate the molecular mechanism of HSD17B5 regulation.

METHODS

Diverse molecular biology techniques were used.

DESIGN AND RESULTS

We identified a KLF15 binding site in the HSD17B5 promoter by using luciferase promoter constructs, EMSA, and chromatin immunoprecipitation assays. Overexpression of KLF15 increased HSD17B5 promoter activity and testosterone formation at least 3-fold in cultured H295R cells. Insulin increased KLF15 mRNA expression according to real-time RT-PCR and increased HSD17B5 promoter activity according to luciferase assays. KLF15 overexpression in combination with insulin, glucocorticoid, and cAMP stimulated adipogenesis in H295R cells. In silico and RT-PCR analyses showed that the KLF15 gene promoter undergoes alternative splicing in a tissue-specific manner. Comparison of the HSD17B5 promoter in seven different species revealed that the KLF15 binding site has no human homolog in species other than orangutans.

CONCLUSIONS

KLF15 is potentially a novel link between the regulation of testosterone production and fat stores by insulin in humans.

Type 5 17beta-hydroxysteroid dehydrogenase (AKR1C3) contributes to testosterone production in the adrenal reticularis

CONTEXT

The human adrenal gland produces small amounts of testosterone that are increased under pathological conditions. However, the mechanisms through which the adrenal gland produces testosterone are poorly defined.

OBJECTIVE

Our objective was to define the role of type 5 17beta-hydroxysteroid dehydrogenase (AKR1C3) in human adrenal production of testosterone.

DESIGN AND METHODS

Adrenal vein sampling was used to confirm ACTH stimulation of adrenal testosterone production. Adrenal expression of AKR1C3 was studied using microarray, quantitative real-time RT-PCR, and immunohistochemical analyses. AKR1C3 knockdown was accomplished in cultured adrenal cells (H295R) using small interfering RNA, followed by measurement of testosterone production.

RESULTS

Acute ACTH administration significantly increased adrenal vein testosterone levels. Examination of the enzymes required for the conversion of androstenedione to testosterone using microarray analysis, quantitative real-time RT-PCR, and immunohistochemistry demonstrated that AKR1C3 was present in the adrenal gland and predominantly expressed in the zona reticularis. Decreasing adrenal cell expression of AKR1C3 mRNA and protein inhibited testosterone production in the H295R adrenal cell line.

CONCLUSIONS

The human adrenal gland directly secretes small, but significant, amounts of testosterone that increases in diseases of androgen excess. AKR1C3 is expressed in the human adrenal gland, with higher levels in the zona reticularis than in the zona fasciculata. AKR1C3, through its ability to convert androstenedione to testosterone, is likely responsible for adrenal testosterone production.

Lack of association between interleukin-1a gene (IL-1a) C (-889) T variant and polycystic ovary syndrome in Chinese women

Polycystic ovary syndrome (PCOS) is associated with the spontaneous development of an aberrant heterogeneous hormonal environment that thought to be related to multiple genetic or environmental factors remain undefined. Previous studies indicated that IL-1a gene C (-889) T, a polymorphism of the gene encoding a protein which involved in various immune responses, inflammatory processes and hematopoiesis, and is associated with PCOS. A total of 205 PCOS patients and 177 healthy controls were included in this study that used PCR-RFLP to detect C (-889) T variant of IL-1a gene. Clinical measures determined previously were included in the SPSS analysis. The results showed that the presence of IL-1a gene C (-889) T polymorphism in PCOS and healthy controls in Chinese women was not significantly different when studying genotype and allele frequencies. (Genotype: chi(2) = 4.62, df = 2, P = 0.10; allele: chi(2) = 1.35, df = 1, P = 0.25). Furthermore, no association was found between metabolic parameters observed and IL-1a genotypes in PCOS patients in this study. In conclusion, IL-1a gene C (-889) T polymorphism does not appear to be risk factor for PCOS in this population of Chinese women.

Integrated view on 17beta-hydroxysteroid dehydrogenases

17beta-Hydroxysteroid dehydrogenases (17beta-HSDs) are important enzymes in steroid metabolism. Long known members of the protein family seemed to be well characterised concerning their role in the regulation of the biological potency of steroid hormones, but today more and more evidence points to pivotal contributions of these enzymes in a variety of other metabolic pathways. Therefore, studies on 17beta-HSDs develop towards metabolomic survey. Latest research results give new insights into the complex metabolic interconnectivity of the 17beta-HSDs. In this paper metabolic activities of 17beta-HSDs will be compared, their interplay with endogenous substrates summarised, and interlacing pathways depicted. Strategies on deciphering the physiological role of 17beta-HSDs and the genetic predisposition for associated diseases will be presented.

Association of the 17-hydroxysteroid dehydrogenase type 5 gene polymorphism (-71A/G HSD17B5 SNP) with hyperandrogenemia in polycystic ovary syndrome (PCOS)

OBJECTIVE

To evaluate the association of an activating single-nucleotide polymorphism (SNP) at position -71 of the promoter of 17beta-hydroxysteroid dehydrogenase type 5 gene (-71A/G HSD17B5 SNP) and polycystic ovary syndrome (PCOS) in a well characterized cohort of caucasian PCOS women with biochemical hyperandrogenemia.

DESIGN

The PCOS patients and unrelated healthy control subjects were genotyped for the -71A/G HSD17B5 SNP. The acquired genotypic data was tested for association with PCOS and other quantitative phenotypic traits of the syndrome in PCOS patients.

SETTING

Subjects were recruited from the Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, at the University Hospital of Patras, Greece. Genotyping and biochemical determinations took place at the Laboratory of Molecular Endrocinology, University of Patras Medical School, Rion, Greece.

PATIENT(S)

Participants comprised 150 caucasian Greek PCOS women with biochemical hyperandrogenism and chronic anovulation and polycystic ovarian morphology on ultrasound and 51 healthy control subjects.

MAIN OUTCOME MEASURE(S)

HSD17B5 genotype, serum testosterone, serum androstenedione.

RESULT(S)

No association of the -71A/G HSD17B5 SNP with PCOS was detected. However, the -71G HSD17B5 variant was associated with increased serum testosterone levels and decreased androstenedione/testosterone ratio.

CONCLUSION(S)

The -71G HSD17B5 variant is not a major component of the molecular pathogenetic mechanisms of PCOS, although it might contribute to the severity of hyperandrogenemia in women with PCOS and biochemical hyperandrogenism.