Association of Polymorphisms of Glutamate Cysteine Ligase Genes GCLC C-129 T and GCLM C-588 T with Risk of Polycystic Ovary Syndrome in Chinese Women

Increased oxidative stress is associated with hyperandrogenemia in polycystic ovary syndrome evidenced by oxidized lipoproteins stimulating rat ovarian androgen synthesis in vitro

PURPOSE

To determine the relationship between serum total testosterone (TT) levels and oxidative stress indices in patients with polycystic ovary syndrome (PCOS), and to investigate the effect of oxidative stress on androgen synthesis and its mechanism in rat ovarian theca-interstitial (T-I) cells.

METHODS

Clinical, hormonal, metabolic, and oxidative stress parameters were analyzed in a cross-sectional case-control study including 626 patients with PCOS and 296 controls. The effects of oxidized low-density lipoprotein (ox-LDL) and oxidized high-density lipoprotein (ox-HDL) on cell proliferation, TT secretion, and expression of key enzymes involved in testosterone synthesis were evaluated in T-I cells.

RESULTS

Serum TT levels were elevated with an increase in ox-LDL levels, whereas glutathione concentrations were lower in the high-TT subgroup than in the low-TT subgroup. The average ovarian volume and ox-LDL and malondialdehyde levels were significant predictors of TT levels in the multivariate regression models. In a rat ovarian T-I cell model, lipoprotein and oxidized lipoprotein treatments stimulated proliferation and promoted testosterone secretion. The mRNA and protein levels of 17α-hydroxylase were significantly higher in oxidized lipoprotein-treated cells than those in lipoprotein-treated cells. The mRNA levels of cholesterol side chain cleavage enzyme and steroidogenic acute regulatory protein were also significantly higher in ox-HDL-treated cells than in HDL-treated cells.

CONCLUSIONS

Oxidative stress can promote androgen production by up-regulating the expression of testosterone synthesis-related enzymes in vitro and may be an essential factor in elevating serum TT levels in patients with PCOS.

Association Between rs2278426 Polymorphism of the ANGPTL8 Gene and Polycystic Ovary Syndrome

Purpose

To study the relationship between the single nucleotide polymorphism (SNP) rs2278426 in the angiopoietin-like protein 8 gene (ANGPTL8) and polycystic ovary syndrome (PCOS).

Patients and methods

A total of 122 patients with PCOS and 108 controls were recruited for comparison of glucose, lipid, insulin, sex hormone, and ANGPTL8 levels. Polymerase chain reaction (PCR) and gene sequencing were performed for comparison of the frequency of the CC, CT, and TT rs2278426 genotypes and the rs2278426 allele distributions between the PCOS and control groups and between the obese and non-obese subgroups of the PCOS and control groups.

Results

The frequency of the T allele was significantly higher in the PCOS group than that in the controls (P = 0.037). In the dominant genetic model, the proportion of the CT+TT genotype in the PCOS group was significantly higher than that in the controls (P = 0.047). Subgroup analysis demonstrated that the T allele proportion was significantly higher in obese PCOS group than obese control group (P = 0.027). PCOS with the CT+TT genotype had significantly higher body mass index (BMI; P = 0.001), triglyceride (TG; P = 0.005), homeostasis model assessment of insulin resistance (HOMA-IR; P = 0.035), testosterone (P = 0.041), and ANGPTL8 (P = 0.037) levels and significantly lower high-density lipoprotein (HDL) levels (P = 0.025) than PCOS with the CC genotype. Obese PCOS group with the CT+TT genotype had significantly higher TG (P = 0.015), luteinizing hormone (LH; P = 0.030), fasting insulin (FINS; P = 0.039), HOMA-IR (P = 0.018), and ANGPTL8 (P = 0.049) levels than obese PCOS group with the CC genotype.

Conclusion

Polymorphisms of rs2278426 may induce glycolipid metabolic disorders by affecting ANGPTL8 levels and functions in Han Chinese females with obesity from the Shandong region, increasing the risk of PCOS in this population.

Evidence for causal effects of polycystic ovary syndrome on oxidative stress: a two-sample mendelian randomisation study

BACKGROUND

Polycystic ovary syndrome (PCOS) is often accompanied by increased oxidative stress levels; however, it is still unclear whether PCOS itself is causally related to oxidative stress (OS), whether OS can increase the occurrence of PCOS, and which characteristics of PCOS increase OS levels. Therefore, this study explored the causal relationship between PCOS, its characteristics, and OS.

METHODS

Two-sample bidirectional and two-sample Mendelian randomisation studies were performed based on publicly available statistics from genome-wide association studies. PCOS; its characteristics, such as testosterone, low-density lipoprotein, high-density lipoprotein; and 11 major OS markers (superoxide dismutase, glutathione S-transferase, glutathione peroxidase, catalase, uric acid, zinc, tocopherol, ascorbic acid, retinol, albumin, and total bilirubin), were studied. The main analytical method used was inverse variance weighting (IVW). Pleiotropy was evaluated using the Mendelian randomisation-Egger intercept. Q and P values were used to assess heterogeneity.

RESULTS

There was no causal relationship between PCOS and the OS indices (all P > 0.05). There was a causal relationship between the OS index, ascorbate level, and PCOS (IVW, odds ratio: 2.112, 95% confidence interval: 1.257-3.549, P = 0.005). In addition, there was a causal relationship between testosterone, low-density lipoprotein, high-density lipoprotein, sex hormone-binding globulin, body mass index, triacylglycerol, age at menarche, and most OS indices according to the IVW method. The F statistics showed that there was no weak instrumental variable. A sensitivity analysis was performed using the leave-one-out method. No pleiotropy was observed. The results were robust, and the conclusions were reliable.

CONCLUSIONS

This study showed for the first time that there was no causal relationship between PCOS and OS. However, there was a causal relationship between the OS index, ascorbate level, and PCOS. It revealed that PCOS itself could not increase OS, and the increase in OS in PCOS was related to other potential factors, such as testosterone, low-density lipoprotein, high-density lipoprotein, sex hormone-binding globulin, body mass index, triacylglycerol, and age at menarche.

Polymorphisms of the GCLC Gene Are Novel Genetic Markers for Susceptibility to Psoriasis Associated with Alcohol Abuse and Cigarette Smoking

The aim of this pilot study was to investigate whether single nucleotide polymorphisms (SNP) in the gene encoding the catalytic subunit of glutamate cysteine ligase (GCLC) are associated with the risk and clinical features of psoriasis. A total of 944 unrelated individuals, including 474 patients with a diagnosis of psoriasis and 470 healthy controls, were recruited for the study. Six common SNPs in the GCLC gene were genotyped using the MassArray-4 system. Polymorphisms rs648595 (OR = 0.56, 95% CI 0.35-0.90; Pperm = 0.017) and rs2397147 (OR = 0.54, 95% CI 0.30-0.98; Pperm = 0.05) were associated with susceptibility to psoriasis in males. In the male group, diplotype rs2397147-C/C × rs17883901-G/G was associated with a decreased risk of psoriasis (FDR-adjusted p = 0.014), whereas diplotype rs6933870-G/G × rs17883901-G/G (FDR-adjusted p = 0.045) showed an association with an increased disease risk in females. The joint effects of SNPs with tobacco smoking (rs648595 and rs17883901) and alcohol abuse (rs648595 and rs542914) on psoriasis risk were observed (Pperm ≤ 0.05). We also found multiple sex-independent associations between GCLC gene polymorphisms and various clinical features such as earlier disease onset, the psoriatic triad, and specific localizations of skin lesions. The present study is the first to show that polymorphisms of the GCLC gene are significantly associated with the risk of psoriasis and related to its clinical features.

Structural and functional changes in rat uterus induced by neonatal androgenization

Fetal or neonatal androgen exposure has a programming effect on ovarian function inducing a polycystic ovarian syndrome-like condition. Its effects on uterine structure and function are poorly studied. The aim of this work was to characterize the temporal course of changes in the rat uterine structure induced by neonatal exposure to aromatizable or not aromatizable androgens. Rats were daily treated with testosterone, dihydrotestosterone or vehicle during follicle assembly period (postnatal days 1 to 5). Uterine histoarchitecture, hormonal milieu, endometrial stromal collagen and capillary density were analyzed at prepubertal, pubertal and adult ages. Our data shows that neonatal androgen exposure induces early and long-lasting deleterious effects on uterine development, including altered adenogenesis and superficial epithelial alterations and suggest a role for altered serum estradiol levels in the maintenance and worsening of the situation. Our results suggest that alterations of the neonatal androgenic environment on the uterus could be responsible for alterations in the processes of implantation and maintenance of the embryo in women with polycystic ovary syndrome.