Identification of the G994T polymorphism in exon 9 of plasma platelet-activating factor acetylhydrolase gene as a risk factor for polycystic ovary syndrome

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.

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.

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

Polycystic ovary syndrome (PCOS) is generally considered a multifactorial disease caused by interactions between multiple susceptible genes and environmental factors. Glutamate cysteine ligase (GCL) is the rate-limiting enzyme in glutathione biosynthesis. This study examined the relationship between single nucleotide polymorphisms (SNPs) in the GCL catalytic subunit (GCLC C-129 T) and the modifier subunit (GCLM C-588 T) and PCOS. The two SNPs were genotyped in 1017 PCOS patients and 793 control women. Clinical, metabolic, hormonal, and oxidative stress parameters were also assessed. The frequencies of the CT + TT genotypes (21.6% vs. 27.7%) and T allele (11.5% vs. 14.7%) of SNP GCLC C-129 T were significantly lower in hyperandrogenism (HA)-PCOS patients than in control women. Logistic regression analysis revealed that the relative hazard of HA-PCOS was lower in individuals with the -129 T allele (CT + TT genotypes) than in those with the CC genotype (OR = 0.723, 95% CI: 0.571-0.915, P = 0.007). When using the GCLC-CC/GCLM-CC combined genotype as the reference category, the GCLC-CT + TT/GCLM-CC combined genotype was a protective factor for PCOS with HA (OR = 0.743, 95% CI: 0.566-0.976, P = 0.033). HA-PCOS patients with the -129 T allele had lower waist circumference, waist-to-hip ratio, and body mass index (BMI) and lower fasting insulin concentration and homeostatic model assessment of insulin resistance after correcting for age and BMI (P < 0.05). The T allele of SNP GCLC C-129 T and its combination with the CC genotype of SNP GCLM C-588 T are associated with decreased risk of HA-PCOS in Chinese women.

Oxidative stress promotes hyperandrogenism by reducing sex hormone-binding globulin in polycystic ovary syndrome

OBJECTIVE

To determine the relationships between circulating sex hormone-binding globulin (SHBG) and oxidized low-density lipoprotein (ox-LDL), total oxidant status, total antioxidant capacity, oxidative stress index, malondialdehyde, and the high-density lipoprotein (HDL) inflammatory index in patients with polycystic ovary syndrome (PCOS) and to investigate the effect of oxidative stress on the expression of SHBG and its mechanism in HepG2 cells.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

A total of 533 women with PCOS and 292 control women were included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Circulating SHBG, hormones, and metabolic and oxidative stress indices were determined in all subjects. The effects of ox-LDL and ox-HDL on the mRNA and protein expression of SHBG and related transcription factors were observed in HepG2 cells.

RESULT(S)

The HDL inflammatory index, total oxidant status, oxidative stress index, and malondialdehyde levels were significantly higher in the three PCOS subgroups with different SHBG levels than in the controls. The ox-LDL and total antioxidant capacity were higher in the PCOS subgroups with SHBG levels <75th percentile compared with the controls or the PCOS subgroup with SHBG levels ≥75th percentile. In HepG2 cells, the SHBG concentration in the culture supernatant, the mRNA levels of SHBG and hepatocyte nuclear factor-4α (HNF-4α), and the protein levels of HNF-4α were significantly lower in ox-LDL- and ox-HDL-treated cells than in the control cells and lipoprotein-treated cells.

CONCLUSION(S)

Oxidative stress inhibits the expression and secretion of SHBG by downregulating HNF-4α in vitro and may be an important factor promoting the occurrence of hyperandrogenemia in PCOS.

GALNT2 Gene Variant rs4846914 Is Associated with Insulin and Insulin Resistance Depending on BMI in PCOS Patients: a Case-Control Study

GALNT2 is a GalNAc transferase that regulates insulin signaling, lipogenesis, and serum lipid fractions. The objective of this study was to investigate the association of GALNT2 rs2144300 and rs4846914 single nucleotide polymorphisms (SNPs) with the risk of polycystic ovary syndrome (PCOS) and related traits. The two SNPs were genotyped in 616 PCOS patients and 482 control subjects. Genetic associations with related traits were also analyzed. The genotype distributions of the two SNPs in PCOS patients were similar to those of normal controls. However, significant differences were noted across the three groups of genotypes with respect to the examined variables. In the PCOS group, subjects with genotype AA at the rs4846914 SNP exhibited an increased fasting serum insulin and homeostasis model insulin resistance (HOMA-IR) index compared with that of corresponding GG or GA genotype carriers (all P < 0.05). When PCOS patients were further separated into obese and non-obese subgroups, the genotype-related effects on insulin and HOMA-IR were more obvious, and variations in BMI and FSH levels were exclusively observed in obese PCOS subjects (all P < 0.05). In addition, fasting plasma glucose levels were affected by the genotypes of the rs2144300 SNP in normal control women (P < 0.05). rs4846914 and rs2144300 polymorphisms in the GALNT2 gene are associated with insulin and HOMA-IR, BMI, and FSH levels in obese PCOS patients and glucose levels in normal control women, respectively, but not with PCOS. GALNT2 rs4846914 AA carrier status may be associated with insulin resistance and related traits in obese patients.

Association of SOD2 A16V and PON2 S311C polymorphisms with polycystic ovary syndrome in Chinese women

PURPOSE

To investigate the relationship between superoxide dismutase 2 (SOD2) A16V and paraoxonase 2 (PON2) S311C gene variants and the risk of polycystic ovary syndrome (PCOS) and evaluate the effects of the genotypes on clinical, hormonal, metabolic and oxidative stress indexes in Chinese women.

METHODS

This is a cross-sectional study of 932 patients with PCOS and 745 control women. For the clinical and metabolic association study of genotypes, 631 patients and 492 controls were included after excluding the subjects with interferential factors. Genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. Serum total oxidant status, total antioxidant capacity (T-AOC), oxidative stress index and malondialdehyde (MDA) levels, and clinical and metabolic parameters were also analyzed.

RESULTS

The prevalence of the A allele of SOD2 A16V polymorphism was significantly greater in patients with PCOS than in control subjects. Genotype (AA + AV) remained a significant predictor for PCOS in prognostic models including age, body mass index, insulin resistance index, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (TGs) as covariates. Patients carrying the A allele had significantly higher serum luteinizing hormone (LH) levels, and the ratio of LH to follicle-stimulating hormone compared with patients with the VV genotype. We also showed that patients carrying the C allele of the PON2 S311C polymorphism had lower T-AOC compared with patients carrying the SS genotype. However, no significant differences were observed in the frequencies of the S311C genotypes and alleles of the PON2 gene between PCOS and control groups.

CONCLUSION

The SOD2 A16V, but not PON2 S311C, polymorphism may be one of the genetic determinants for PCOS in Chinese women.

Lipoprotein-associated phospholipase A2: The story continues

Inflammation is thought to play an important role in the pathogenesis of vascular diseases. Lipoprotein-associated phospholipase A2 (Lp-PLA2) mediates vascular inflammation through the regulation of lipid metabolism in blood, thus, it has been extensively investigated to identify its role in vascular inflammation-related diseases, mainly atherosclerosis. Although darapladib, the most advanced Lp-PLA2 inhibitor, failed to meet the primary endpoints of two large phase III trials in atherosclerosis patients cotreated with standard medical care, the research on Lp-PLA2 has not been terminated. Novel pathogenic, epidemiologic, genetic, and crystallographic studies regarding Lp-PLA2 have been reported recently, while novel inhibitors were identified through a fragment-based lead discovery strategy. More strikingly, recent clinical and preclinical studies revealed that Lp-PLA2 inhibition showed promising therapeutic effects in diabetic macular edema and Alzheimer's disease. In this review, we not only summarized the knowledge of Lp-PLA2 established in the past decades but also emphasized new findings in recent years. We hope this review could be valuable for helping researchers acquire a much deeper insight into the nature of Lp-PLA2, identify more potent and selective Lp-PLA2 inhibitors, and discover the potential indications of Lp-PLA2 inhibitors.

G994T polymorphism in exon 9 of plasma platelet-activating factor acetylhydrolase gene and lung ultrasound score as prognostic markers in evaluating the outcome of acute respiratory distress syndrome

The present study aimed to discover potential biomarkers for predicting the prognosis of acute respiratory distress syndrome (ARDS) in conjunction with lung ultrasound (LUS). Blood samples from 112 ARDS patients were collected to compare their partial oxygen pressure (PaO₂)/fraction of inspired oxygen (FiO₂), positive end-expiratory pressure (PEEP), lactic acid, sequential organ failure assessment (SOFA) score, clinical pulmonary infection score (CPIS) and APACHE II score. Kaplan-Meier plots and the log-rank test were performed to analyse the association between the platelet-activating factor acetylhydrolase (PAFAH) G994T polymorphism and the outcome of ARDS regarding mortality. A negative correlation between the LUS score and PaO₂/FiO₂, PEEP and lactic acid, as well as with the SOFA, CPIS and APACHE II score was confirmed with correlation coefficients of -0.493, -0.548, -0.642, -0.598, -0.566 and -0.567, respectively (all P<0.05). The activity of PAFAH and high-density lipoprotein-PAFAH in the serum collected from subjects of the GG genotype was similar to that in subjects of the GT genotype, but the low-density lipoprotein-PAFAH activity in the serum collected from GG subjects was significantly higher than that in GT subjects. An evident reduction in the PEEP, level of lactic acid, as well as the SOFA, CPIS and APACHE II score was observed in GG subjects, accompanied by a significantly increased PaO₂/FiO₂. Kaplan-Meier analysis indicated that subjects with a high LUS score had a significantly higher survival rate than those with a low LUS score, and the mortality risk for GG subjects was significantly lower than that for GT subjects. Finally, among all groups (genotype and LUS groups), GG subjects with a high LUS score had the lowest mortality risk, whereas GT subjects with a low LUS score had the highest mortality risk. In addition, the survival rate of GT subjects with a high LUS score was higher than that of GG subjects with a low LUS score. In conclusion, the combination of the LUS score and the G994T polymorphism in exon 9 of the PAFAH gene may be used as a potential prognostic marker for ARDS.

Association of GPx1 P198L and CAT C-262T Genetic Variations With Polycystic Ovary Syndrome in Chinese Women

Background: Oxidative stress plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). Glutathione peroxidase 1 (GPx1) and catalase (CAT) are the major intracellular antioxidant enzymes that can detoxify hydrogen peroxide into water, preventing cellular injury from reactive oxygen species. The aim of the present study was to investigate the association of GPx1 P198L (Pro198Leu, C559T, rs1050450) and CAT C-262T (rs1001179) genetic polymorphisms with the risk of PCOS and evaluate the effects of the genotypes on clinical, hormonal, metabolic and oxidative stress parameters in Chinese women. Methods: This is a case-control study of 654 patients with PCOS and 535 controls. The GPx1 P198L, CAT C-262T, and superoxide dismutase 2 (SOD2) A16V genotypes were determined by polymerase chain reaction amplification and restriction analysis. Clinical, hormonal, metabolic and oxidative stress parameters were also analyzed. Results: The frequencies of the PL + LL genotype (14.1 vs. 8.4%) and L allele (7.3 vs. 4.4%) of GPx1 P198L polymorphism were significantly higher in patients with PCOS than in control subjects. Genotype (PL + LL) remained a significant predictor for PCOS in prognostic models including age, body mass index (BMI), insulin resistance index, total cholesterol, triglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol as covariates (OR = 2.105, 95%CI: 1.330-3.331, P = 0.001). Patients carrying the L allele had relatively high average ovarian volume, waist circumference, and malondialdehyde levels (P < 0.07) compared with patients with the PP genotype. We also demonstrated that the subjects with both GPx1 L and SOD2 A alleles further increase the risk of PCOS compared with the individuals carrying the PP/VV genotype after adjusting for age and BMI (OR = 5.774, 95%CI: 2.243-14.863, P < 0.001). However, no significant differences were observed in the frequencies of the CAT C-262T genotypes and alleles between PCOS and control groups. Conclusions: The GPx1 P198L, but not CAT C-262T, genetic polymorphism is associated with the risk of PCOS in Chinese women.

Platelet-activating factor acetylhydrolases: An overview and update

Platelet-activating factor acetylhydrolases (PAF-AHs) are unique members of the phospholipase A₂ family that can hydrolyze the acetyl group of PAF, a signaling phospholipid that has roles in diverse (patho)physiological processes. Three types of PAF-AH have been identified in mammals, one plasma type and two intracellular types [PAF-AH (I) and PAF-AH (II)]. Plasma PAF-AH and PAF-AH (II) are monomeric enzymes that are structurally similar, while PAF-AH (I) is a multimeric enzyme with no homology to other PAF-AHs. PAF-AH (I) shows a strong preference for an acetyl group, whereas plasma PAF-AH and PAF-AH (II) also hydrolyze phospholipids with oxidatively modified fatty acids. Plasma PAF-AH has been implicated in several diseases including cardiovascular disease. PAF-AH (I) is required for spermatogenesis and is increasingly recognized as an oncogenic factor. PAF-AH (II) was recently shown to act as a bioactive lipid-producing enzyme in mast cells and thus could be a drug target for allergic diseases. This article is part of a Special Issue entitled Novel functions of phospholipase A2 Guest Editors: Makoto Murakami and Gerard Lambeau.

Associations Between TP53 and MDM2 Polymorphisms and the Follicle-Stimulating Hormone/Luteinizing Hormone Ratio in Infertile Women

AIMS

This is a follow-up study based on the results of our previous article, to further explore the effect of the TP53 codon 72 (rs1042522) and MDM2 SNP309 (rs2279744) polymorphisms on basal follicle-stimulating hormone (FSH)/luteinizing hormone (LH) ratios in infertility women.

MATERIALS AND METHODS

The distribution of two genetic polymorphisms (rs1042522 and rs2279744) and basal FSH/LH ratios were tested and analyzed in 1051 in vitro fertilization (IVF) patients at a university-affiliated hospital.

RESULTS

The TP53 codon 72 polymorphism had a significant association with the FSH/LH ratio (group I: FSH/LH <2.3 and group II: FSH/LH ≥2.3) (C/C vs. G/G: odds ratio [OR] = 1.69, 95% confidence interval [CI]: 1.07-2.65, p = 0.02; G/C vs. G/G: OR = 1.86, 95% CI: 1.25-2.77, p = 0.002). In a stratification analysis, C allele carriers and the C/C genotype showed a strong association with positive clinical pregnancy outcomes after IVF compared with G allele carriers and the G/G genotype in the recessive, dominant, and allelic genetic models in group I (C/C vs. G/G: OR = 1.84, 95% CI: 1.25-2.69, p = 0.01; C/C vs. G carrier: OR = 1.52, 95% CI: 1.12-2.07, p = 0.01; C carrier vs. G/G: OR = 1.46, 95% CI: 1.07-2.01, p = 0.02; C allele vs. G allele: OR = 1.34, 95% CI: 1.11-1.62, p = 0.003), no significant associations by stratification were observed for group II. No associations were found between MDM2 SNP309 and either of two groups.

CONCLUSION

The TP53 codon 72 polymorphism is associated with FSH/LH ratios, suggesting that it is a potential predictive genetic marker of IVF outcome in patients younger than 35 years of age with baseline FSH levels below 10 IU/L and who have an FSH/LH ratio <2.3.

Effects of apoC1 genotypes on the hormonal levels, metabolic profile and PAF-AH activity in Chinese women with polycystic ovary syndrome

Background

Elevated serum levels of apolipoprotein (apo) C1 may be an early protein marker of metabolic abnormality in women with polycystic ovary syndrome (PCOS). It is not clear, however, whether there are any relationships between the apoC1 rs4420638A/G and -317deletion (H1)/insertion (H2) polymorphisms and PCOS. We investigated the relationship between these two variants and the risk of PCOS, evaluated the genotypic effects on clinical, hormonal and metabolic indexes and plasma platelet-activating factor acetylhydrolase (PAF-AH) activity, and defined the association of apoC1 gene variants with apoE ε2/ε3/ε4 polymorphisms.

Methods

This is a cross-sectional study of 877 women with PCOS and 761 controls. The apoC1 rs4420638A/G genotype was determined by a Taqman real-time PCR allelic discrimination assay. The apoC1–317H1/H2 and apoE ε2/ε3/ε4 genotypes were measured using PCR and restriction fragment length polymorphism analysis. The clinical, hormonal and metabolic parameters and PAF-AH activity were measured.

Results

The frequencies of apoC1 rs4420638A/G and -317H1/H2 genotypes and alleles were similar between PCOS and control groups (P > 0.05). However, the rs4420638 G allele was related to increased serum luteinizing hormone, cholesterol and apoB levels, and the ratio of apoB to apoA1 (P < 0.05), and the -317H1H1 genotype was associated with a higher acne grade score and a higher ratio of apoB-PAF-AH to H-PAF-AH activity (P < 0.05) in patients with PCOS. We also demonstrated that the apoC1 rs4420638A/G and -317H1/H2 gene variants existed in moderate to reasonably high linkage disequilibrium with apoE ε2/ε3/ε4 polymorphisms in Chinese women.

Conclusion

The apoC1 rs4420638A/G and -317H1/H2 gene variants might be involved in endocrine abnormalities of reproductive axis, metabolic abnormalities and chronic inflammation in PCOS, although no association was observed between the apoC1 genetic variants and the risk of PCOS in Chinese women.

[Association between platelet-activating factor acetylhydrolase gene polymorphisms and gastrointestinal bleeding in children with Henoch-Schönlein purpura]

OBJECTIVE

To study the association between the single nucleotide polymorphisms (SNPs) of the ninth exon Val279Phe of platelet-activating factor acetylhydrolase (PAF-AH) gene and gastrointestinal bleeding in children with Henoch-Schönlein purpura (HSP).

METHODS

A total 516 children with HSP were enrolled, among whom 182 had gastrointestinal bleeding and 334 had no gastrointestinal bleeding. PCR was used to investigate the distribution of genotypes and alleles in the SNPs of Val97Phe. The plasma PAF-AH activity was measured, as well as the levels of platelet-activating factor (PAF), granular membrane protein-140 (GMP-140), β-thromboglobulin (β-TG), and platelet factor 4 (PF4).

RESULTS

The Val279Phe genotype and allele frequencies were in Hardy-Weinberg equilibrium, and the homozygous genotype TT and heterozygotes accounted for 0.97% and 6.05% respectively. The gastrointestinal bleeding group had a significantly higher allele frequency than the control group (5.22% vs 3.33%; P<0.01). The HSP patients with GG genotype in the gastrointestinal bleeding group had significantly higher levels of plasma PAF and GMP-140 than those in the non-gastrointestinal bleeding group (P<0.05), while the non-gastrointestinal bleeding group had a significantly higher PAF-AH activity than the gastrointestinal bleeding group (P<0.05). There were no significant differences in β-TG and PF4 between the two groups (P>0.05).

CONCLUSIONS

Val279Phe gene polymorphisms in PAF-AH are associated with PAF-AH activity and PAF and GMP-140 levels and may be a risk factor for HSP with gastrointestinal bleeding.

Effect of the R92H and A379V genotypes of platelet-activating factor acetylhydrolase on its enzyme activity, oxidative stress and metabolic profile in Chinese women with polycystic ovary syndrome

Background

The G994T polymorphism in platelet-activating factor acetylhydrolase (PAF-AH) gene is associated with the risk of polycystic ovary syndrome (PCOS). The aim of this study was to investigate the relationship between R92H and A379V variants of the PAF-AH gene and the risk of PCOS and to evaluate the effects of the genotypes on PAF-AH activities and clinical, metabolic and oxidative stress indexes in Chinese women.

Methods

A total of 862 patients with PCOS based on the Rotterdam consensus criteria and 750 control women from a population of Chinese Han nationality in the Chengdu area were studied from 2006–2015. PAF-AH genotypes were determined by PCR and restriction fragment length polymorphism analysis. Plasma PAF-AH, high-density lipoprotein (HDL)-associated PAF-AH (H-PAF-AH) and apolipoprotein (apo) B-containing lipoprotein-associated PAF-AH (apoB-PAF-AH) activities were measured using the trichloroacetic acid precipitation procedure with PAF C-16 as a substrate. Circulating markers of oxidative stress, including serum total oxidant status, total antioxidant capacity, oxidative stress index and malondialdehyde levels, and clinical and metabolic parameters were also analyzed.

Results

No significant differences were observed in the frequencies of R92H and A379V genotypes and alleles of the PAF-AH gene between PCOS and control groups (P > 0.05). Compared with patients with the 92RR genotype, patients with H allele of R92H (RH + HH genotype) had significantly higher plasma PAF-AH and apoB-PAF-AH activities (P < 0.05) and tended to exhibit increased H-PAF-AH activity (P = 0.063) after adjusted for age and BMI. However, when serum LDL-C, HDL-C, TG and HOMA index were added as covariates, the comparisons no longer remained statistical significance (P > 0.05). There were no significant differences in clinical, hormonal, metabolic and circulating oxidative stress parameters and the frequencies of PAF-AH G449T genotype according to PAF-AH R92H or A379V genotyping in patients with PCOS and control women.

Conclusions

There were no significant associations between R92H and A379V variants of PAF-AH gene and risk of PCOS in Chinese women. The increased plasma PAF-AH and apoB-PAF-AH activities in patients with H allele of R92H are related to the R92 → H variation, changes in plasma lipoprotein levels, insulin resistance, aging, and gaining weight and thus may be involved in the pathogenesis of PCOS and the increased risks of future cardiovascular diseases.

Oxidative stress status in Chinese women with different clinical phenotypes of polycystic ovary syndrome

OBJECTIVE

To determine oxidative stress status and its association with clinical and metabolic parameters in Chinese women with different clinical phenotypes of polycystic ovary syndrome (PCOS).

DESIGN

A cross-sectional study.

PATIENTS

A total of 544 patients with PCOS and 468 control women were included.

MEASUREMENTS

The total oxidant status (TOS) was determined using a microplate colorimetric method. Total antioxidant capacity (T-AOC), oxidative stress index (OSI, the ratios of TOS to T-AOC) and clinical, hormonal and metabolic parameters were also analysed.

RESULTS

TOS and OSI were significantly higher in each of the four PCOS phenotypes based on the Rotterdam criteria than in the control women and higher in patients with hyperandrogenism (HA) than in those without HA (P < 0·05). TOS, T-AOC and OSI were higher in lean patients than in lean controls (P < 0·05). These values, except OSI, were also higher in overweight/obese patients than in lean patients, and lean or overweight/obese controls (P < 0·05). Multivariate regression analysis demonstrated that apolipoprotein (apo)A1, the Ferriman-Gallwey score, triglyceride (TG), oestradiol (E₂ ), high-density lipoprotein cholesterol (HDL-C) and 2-h glucose levels were the main predictors of TOS; the Ferriman-Gallwey score, E₂ , apoA1, TG and HDL-C levels were the main predictors of OSI.

CONCLUSIONS

Patients with PCOS with HA have higher oxidative stress levels compared with those without HA. The increased oxidative stress in PCOS is related to HA status, increased plasma glucose, TG, HDL-C and E₂ levels, decreased apoA1 concentrations and a relative shortage of antioxidant capacity.

Activity and distribution of plasma platelet-activating factor acetylhydrolase in women with gestational diabetes mellitus and their neonates

BACKGROUND

Abnormal activity and distribution of plasma platelet-activating factor acetylhydrolase (PAF-AH) are associated with chronic inflammatory status. In this study, we investigate the activity and distribution of plasma PAF-AH and their association with metabolic components in mothers with gestational diabetes mellitus (GDM) and in their neonates.

METHODS

Based on the International Association of Diabetes Pregnancy Study Group criteria, we performed a case-controlled study of 101 women with GDM, 98 women with uncomplicated pregnancies, 142 neonates of mothers with GDM and 121 neonates of mothers with uncomplicated pregnancies. Plasma PAF-AH, high-density lipoprotein (HDL)-associated PAF-AH (H-PAF-AH) and apolipoprotein (apo) B-containing lipoprotein-associated PAF-AH (apoB-PAF-AH) activities were measured using the trichloroacetic acid precipitation procedure with PAF C-16 as a substrate.

RESULTS

The plasma PAF-AH and apoB-PAF-AH activities, triglyceride (TG) levels, atherogenic index and TG/HDL-C ratio were increased, and the H-PAF-AH proportions were decreased in the mothers with GDM compared with the control mothers (p < 0.05). Multivariate regression analyses demonstrated that the apoB and TG levels were significant predictors of plasma PAF-AH or apoB-PAF-AH activities, while the low-density lipoprotein-cholesterol levels, weight gain during pregnancy and age were associated with H-PAF-AH activities. The neonates of mothers with GDM had higher plasma insulin and glucose concentrations (p < 0.05) and tended to exhibit increased serum apoB levels (p = 0.062) compared with the neonates of mothers with uncomplicated pregnancies.

CONCLUSIONS

The mothers with GDM presented with a state of chronic inflammation, and these mothers and their neonates also exhibited unfavourable metabolic profiles in terms of glucose and lipids. Copyright © 2016 John Wiley & Sons, Ltd.

Lactonase activity and status of paraoxonase 1 in Chinese women with polycystic ovarian syndrome

OBJECTIVE

To study the relationship between the lactonase activities and status of paraoxonase 1 (PON1) and its association with the PON1 genetic polymorphisms in women with polycystic ovarian syndrome (PCOS).

DESIGN

A case-control study.

METHODS

A total of 455 PCOS patients and 441 control women were included in this study. The lactonase activities and concentrations of PON1 were assayed using 5-thiobutyl butyrolactone (TBBL) and 7-O-diethylphosphoryl-3-cyano-4-methyl-7-hydroxycoumarin (DEPCyMC) respectively. A normalized lactonase activity (NLA) was estimated based on the ratio of TBBLase:DEPCyMCase activity. The PON1 genotypes, serum malondialdehyde (MDA) levels and total antioxidant capacity were analyzed.

RESULTS

The lactonase activities and levels of PON1 were higher in PCOS patients than in the control women. However, the NLA did not significantly differ between groups. The -108C→T variation of the PON1 gene showed decreased lactonase activities and levels of PON1 in a genotype-dependent manner (CC>CT>TT); the 192Q→R variation of the PON1 gene showed increased PON1 lactonase activities and NLA; and the 55L→M variation of the PON1 gene showed decreased lactonase activities and levels of PON1 but an increased NLA. A multivariable regression analysis showed that the -108C/T, 192Q/R, and 55L/M variations of the PON1 gene, serum apolipoprotein A1, and MDA levels were significant predictors of PON1 lactonase activity, PON1 level, and NLA.

CONCLUSIONS

The serum lactonase activities and concentrations of PON1 are increased in PCOS patients. The increased oxidative stress and the -108C/T, 192Q/R, and 55L/M genetic polymorphisms of PON1 may be associated with these changes.

Antioxidant properties of high-density lipoproteins are impaired in women with polycystic ovary syndrome

OBJECTIVE

To determine the relationships among the inflammatory index, intrinsic oxidation levels, lipid and apolipoprotein (apo)A-I concentrations of high-density lipoprotein (HDL), and polycystic ovary syndrome (PCOS).

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

A total of 425 patients with PCOS and 441 control women were included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The HDL inflammatory index (HII) was determined using a cell-free fluorometric assay. Intrinsic HDL oxidation levels, HDL-free cholesterol, HDL-cholesterol ester, HDL-triglyceride, serum apoA-I, and malondialdehyde levels were also measured.

RESULT(S)

The mean HII value and the frequency of HII ≥1 were significantly higher in the PCOS group (0.77 ± 0.54, 27.1%) than in the control group (0.53 ± 0.37, 8.4%). These values were also higher in each of the 4 PCOS phenotypes based on the Rotterdam criteria than in the controls, and higher in patients with hyperandrogenism (HA) + oligo- and/or anovulation (OA) phenotype than in those with OA + polycystic ovary (PCO) phenotype. Furthermore, patients with PCOS with OA + PCO had lower malondialdehyde and intrinsic HDL oxidation levels compared with those with HA. Multivariate regression analysis demonstrated that PCOS, HDL-cholesterol ester, and E2 levels were the main predictors of HII value.

CONCLUSION(S)

The impairment of HDL antioxidant/anti-inflammatory function in PCOS is related to HA status, increased oxidative stress, and abnormalities in HDL components and thus may contribute to PCOS pathogenesis and increase the risks of future cardiovascular diseases.

Naturally Occurring Missense Mutation in Plasma PAF-AH Among the Japanese Population

A single nucleotide polymorphism in the plasma PAF-AH enzyme, i.e., G994T, which causes the substitution of Val at amino acid 279 with Phe (V279F), has been found in the Japanese population. This enzyme preferentially degrades oxidatively modulated or truncated phospholipids; therefore, it has been suggested that this enzyme may prevent the accumulation of proinflammatory and proatherogenic oxidized phospholipids. This hypothesis is supported by the higher prevalence of the V279F mutation in patients with asthmatic and atherosclerotic diseases, as compared with healthy controls. This mutation is rare in the Caucasian population. The plasma PAF-AH mass and enzyme activity are distributed over a wide range in the plasma and they are positively correlated with low-density lipoprotein (LDL) cholesterol. However, several clinical studies in the Caucasian population have suggested that this enzyme has the opposite role. This enzyme plays an active role in the development and progression of atherosclerosis via proinflammatory and proatherogenic lysophosphatidylcholine and oxidized fatty acids produced through the oxidation of LDL by this enzyme. Thus, plasma PAF-AH is a unique enzyme with dual roles in human inflammatory diseases. In this chapter, on the basis of recent findings we describe the association between a naturally occurring missense mutation in plasma PAF-AH and human diseases especially including atherosclerosis and asthma.

Effects of apolipoprotein E genotypes on metabolic profile and oxidative stress in southwest Chinese women with polycystic ovary syndrome

OBJECTIVE

Apolipoprotein (APO) E genetic polymorphism plays an important role in lipid and lipoprotein metabolism, and has been shown to be associated with the risk of metabolic and cardio-cerebrovascular diseases and late-onset Alzheimer's disease. It is not clear, however, whether there are any relationships between the APOE genotypes and PCOS in Chinese women. The aim of this study was to investigate the relationship between APOE genotypes and the risk of polycystic ovary syndrome (PCOS) and to evaluate the effects of the genotypes on metabolic profile and oxidative stress in south-west Chinese women.

STUDY DESIGN

A total of 625 patients with PCOS based on the Rotterdam consensus criteria and 514 control women from a population of Chinese Han nationality in the Chengdu area were studied during 2006-2012. APOE genotypes were determined by PCR and restriction fragment length polymorphism analysis. Clinical and metabolic parameters, serum malondialdehyde concentration, and total antioxidant capacity were analyzed.

RESULTS

No significant differences were found in the frequencies of APOE genotypes (E2/2, E2/3, E2/4, E3/3, E3/4, E4/4) and alleles (ε2, ε3, ε4) between PCOS and control groups. Compared with ε3 homozygotes (APOE3/3), however, ε2 carriers (APOE2/2+APOE2/3+APOE2/4) had significantly higher body mass index, waist circumference and waist-to-hip ratio, a more adverse glucose and insulin metabolic profile, lower high density lipoprotein (HDL)-cholesterol (C) and APOA1 levels, higher triglyceride (TG)/HDL-C ratio and prevalence of metabolic syndrome (MS), whereas ε4 carriers (APOE3/4+APOE4/4) had higher total cholesterol (TC) and low density lipoprotein (LDL)-C levels in patients with PCOS.

CONCLUSIONS

In a cohort of south-west Chinese women, there were no significant associations between any APOE genotype and PCOS. The APOE ε2 allele seems to be related to abdominal obesity, insulin resistance and MS in PCOS women.

Paraoxonase lactonase activity (PON-HTLase), asymmetric dimethylarginine (ADMA) and platelet activating factor-acetylhydrolase (PAF-AH) activity in non-obese women with PCOS

OBJECTIVE

Paraoxonase1 (PON1), exhibits both esterase activity (PON1-AREase) and homocysteine thiolactonase activity (PON1-HTLase) which respectively prevent LDL oxidation and detoxify homocysteine thiolactone (HTL). Platelet-activating factor-acetylhydrolase (PAF-AH) is an antioxidant enzyme preventing LDL oxidation by hydrolysis of oxidized phospholipids. Both of these enzymes exhibit a proatherogenic role. ADMA is an endogenous inhibitor of nitric oxide (NO) synthesis causing endothelial dysfunction. The aim was to compare non-obese PCOS patients with a BMI matched control group using the following characteristics: serum PON1-HTLase, ADMA, PAF-AH, and lipid and hormonal parameters.

RESULTS

77 women with PCOS and 25 healthy subject were recruited for this study, The controls were non-obese BMI and age matched with the patients. There were no significant differences with respect to age, BMI, FSH, free testosterone, DHEA, androstenadion, total cholesterol, triglycerides, HDL, LDL, VLDL, fasting glucose/insulin ratio and HOMA-IR among the groups (p > 0.05). However, total testosterone and fasting glucose levels were significantly higher in the PCOS group (p < 0.05). On the other hand, PON1-HTLase levels (39.6 ± 5.77 vs. 33.8 ± 8.2, p = 0.02) were significantly lower in the PCOS group while ADMA levels (1.14 ± 0.6 vs. 3.37 ± 6.4, p = 0.004) were significantly higher in the PCOS group. However, there was no significant difference in PAF-AH activity among the groups.

CONCLUSIONS

Decreased PON1-HTLase and increased ADMA levels might be a relevant marker for the development of future atherosclerotic heart disease (AHD) in non-obese PCOS patients. Further studies are needed to confirm our results.

Maternal and fetal plasma platelet-activating factor acetylhydrolase activity and distribution in pre-eclampsia

BACKGROUND

Distribution of platelet-activating factor acetylhydrolase (PAF-AH) in lipoproteins plays important roles in the onset of inflammation and atherosclerosis. We hypothesized that women with pre-eclampsia (PE), showing signs of inflammation and oxidative stress, and their fetuses have aberrations of PAF-AH activity and distribution.

METHODS

Maternal and fetal plasma PAF-AH activity, high-density lipoprotein (HDL)-associated PAF-AH (H-PAF-AH) and low-density lipoprotein (LDL)-associated PAF-AH (L-PAF-AH) were examined in women with PE (n = 127) and in women with uncomplicated pregnancies (n = 88).

RESULTS

The neonates of women with severe PE (n = 42) had significantly higher plasma PAF-AH, L-PAF-AH activities, and ratio of L-PAF-AH to H-PAF-AH activities than the neonates of women with normal pregnancies (n = 83). The mothers with severe PE (n = 106) and their neonates presented a significantly higher atherogenic index (AI) and triglyceride (TG)/HDL cholesterol (C) ratio than the control mothers and their neonates. The ratio of L-PAF-AH to H-PAF-AH activities correlated positively with TG levels, TG/HDL(C) ratio, and AI and negatively with HDL(C) levels in the neonates of women with PE.

CONCLUSION

The neonates of women with severe PE presented with a chronic inflammation status, increased oxidative stress, and unfavorable lipid changes, which may potentially link to related complications responsible for oxidative stress and inflammation in later life.

Utility of Lp-PLA2 in lipid-lowering therapy

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a vascular-specific inflammatory marker. It is so named because of its association with low-density lipoprotein in plasma. Atherosclerosis is an inflammatory disease. Lp-PLA2 is recognized as a risk marker in primary or secondary prevention of atherosclerosis. Elevated Lp-PLA2 levels are associated with the increased risk for cardiovascular events, even after multivariable adjustment for traditional risk factors. Patients with dyslipidemia are shown to benefit largely from the modification of Lp-PLA2. The degree of coronary artery disease (0-, 1-, 2-, or 3-vessel disease) and plasma low-density lipoprotein cholesterol significantly correlated to Lp-PLA2 levels. The low biologic fluctuation and high vascular specificity of Lp-PLA2 make it possible to use a single measurement in clinical decision making, and it also permits clinicians to follow the Lp-PLA2 marker serially. Simvastatin significantly reduces macrophage content, lipid retention, and the intima to media ratio but increased the content of smooth muscle cells in atherosclerotic lesions. Statin treatment markedly reduced Lp-PLA2 in both plasma and atherosclerotic plaques with attenuation of the local inflammatory response and improved plaque stability due to reduced inflammation and decreased apoptosis of macrophages. Darapladib, an inhibitor of Lp-PLA2 when added to lipid-lowering therapy such as statins, offers great benefit in the reduction of plaque formation. This article explores the atherosclerotic process at molecular level, role of Lp-PLA2 in atherosclerosis, the effect of lipid-lowering drugs on Lp-PLA2, effect of direct Lp-PLA2 inhibitor darapladib in the atherosclerosis process, the therapeutic implications of Lp-PLA2 as risk marker, and finally the net effect on plaque stabilization.

Evidence for association between paraoxonase 1 gene polymorphisms and polycystic ovarian syndrome in southwest Chinese women

OBJECTIVE

The aim of this study was to investigate the relationship between 192Q/R and 55L/M polymorphisms of paraoxonase 1 (PON1) gene and polycystic ovarian syndrome (PCOS) in Chinese women.

DESIGN

A case-control study.

METHODS

A total of 1113 subjects (610 patients with PCOS and 503 control women) from a population of Chinese Han nationality in Chengdu area were included in this study. PON1 genotypes were studied using PCR and restriction fragment length polymorphism analysis. Clinical and metabolic parameters were analyzed.

RESULTS

The frequencies of PON1 192RR genotype and R allele were significantly higher in patients with PCOS than in control women (44.6 vs 36.4%, 0.667 vs 0.610 respectively). The 192RR genotype remained a significant predictor for PCOS (odds ratio (RR/QR)(+)(QQ): 1.656, 95% confidence interval: 1.156-2.371) in prognostic models including age, body mass index, insulin resistance index, triglyceride, HDL, and LDL as covariates. Compared with patients with QQ genotype, patients with RR or QR genotype had significantly higher waist circumference and fasting insulin and triglyceride levels, patients with RR genotype had significantly higher waist-to-hip ratio, and patients with QR genotype had significantly higher homeostasis model assessment of insulin resistance. Such relationships were not detected in the control women. No significant differences were found in the frequencies of PON1 55L/M genotype and allele between PCOS and control groups.

CONCLUSIONS

The 192Q/R, but not 55L/M, polymorphism in PON1 gene is associated with the risk of PCOS in south-west Chinese women.

Apolipoprotein E-containing HDL-associated platelet-activating factor acetylhydrolase activities and malondialdehyde concentrations in patients with PCOS

PAF and PAF-like oxidized phospholipids hydrolysed by platelet-activating factor (PAF) acetylhydrolase (AH) are potent lipid mediators involved in inflammation and atherosclerosis. Apolipoprotein (apo) E-containing high-density lipoprotein (HDL) has antioxidant, anti-inflammatory and anti-atherogenic properties. The study investigated apoE-containing HDL-associated PAF-AH (HDL-PAF-AH) and total (apoE-containing+apoE-poor) HDL-PAF-AH activities as well as malondialdehyde (MDA) concentration in 291 patients with polycystic ovary syndrome (PCOS) using the Rotterdam consensus criteria and 281 control women. Compared with the control women, patients with hyperandrogenism+oligo/anovulation+polycystic ovaries (PCO) or hyperandrogenism+PCO had lower total, apoE-containing and apoE-poor HDL-PAF-AH activities, while those with oligo/anovulation+PCO showed decreased total and apoE-poor HDL-PAF-AH activities. Other factors including insulin resistance and obesity in PCOS had the adverse effects associated with the HDL-PAF-AH activities. Serum MDA concentration was associated with PCOS, hyperandrogenism, insulin resistance and hypertriglyceridaemia in patients with PCOS. Decreased total and apoE-containing HDL-PAF-AH activities and increased serum MDA concentration may contribute to the pathogenesis of PCOS and potentially link to related complications responsible for oxidative stress and inflammation such as an increased risk for type 2 diabetes mellitus and/or future cardiovascular diseases in PCOS patients.