Tumor necrosis factor alpha (-308), interleukin-6 (-174) and interleukin-10 (-1082) gene polymorphisms in polycystic ovary syndrome.

OBJECTIVE: The imbalance between pro- and anti-inflammatory cytokines and polymorphism of cytokine genes may play a role in the etiology of the polycystic ovary syndrome (PCOS). The aim of this study was to investigate the association of polymorphisms of TNFalpha, IL-6 and IL-10 genes with the occurrence and the clinical/laboratory characteristics of PCOS in the Turkish population. STUDY DESIGN: Single nucleotide polymorphisms (SNPs) of TNFalpha (-308 G/A), IL-6 (-174 G/C), IL-10 (-1082 G/A) genes in DNA from peripheral blood leukocytes of 97 PCOS patients and 95 healthy control women were investigated. RESULTS: There is a tendency toward lower frequency of the IL-6 CC genotype and C allele among PCOS women compared with healthy controls although the difference did not reach a significant level. No notable differences were observed in allele or genotype frequencies for TNFalpha and IL-10 genes between groups. The concomitant presence of wild homozygous TNFalpha genotype together with mutant IL-6 C allele has a protective effect against PCOS with an OR=0.45 (95% CI=0.23-0.86). While TNFalpha (-308) and IL-10 (-1082) genotypes did not influence clinical/laboratory parameters in PCOS, IL-6 (-174) CC or pooled CG+CC genotypes have lower glucose, insulin, HOMA, cholesterol, triglyceride, and LDL-C, and higher GIR and HDL-C values than GG genotypes. CONCLUSIONS: We suggest that the IL-6 promoter region polymorphism may be related to occurrence and metabolic abnormalities seen in PCOS in the Turkish population. However, more studies with larger sample size are necessary to support our findings in other populations before any statement can be made about the relationship between PCOS and cytokine polymorphism.

Tumor necrosis factor alpha, interleukin-6 and interleukin-10 polymorphisms in preeclampsia.

AIM: Preeclampsia (PE) is one of the most serious disorders of pregnancy. The imbalance between pro- and anti-inflammatory cytokines may play a role in its etiology. The aim of the present study was to investigate whether cytokine gene polymorphism is associated with PE, and to evaluate the relationship between genotypes and clinical/laboratory manifestation of PE. METHODS: We investigated single nucleotide polymorphisms of tumor necrosis factor (TNF)alpha(-308 G/A), interleukin (IL)-6 (-174 G/C), IL-10 (-1082 G/A) genes in DNA from peripheral blood leukocytes of 101 PE patients and 95 healthy control women. RESULTS: In PE, there was a significant increase of the IL-10 (-1082) A allele frequency (P = 0.04). No significant differences were found in genotypes or allele frequencies of TNFalpha(-308) and IL-6 (-174) genes between PE women and controls. While TNFalpha(-308) and IL-6 (-174) genotypes did not influence clinical/laboratory parameters in PE, IL-10 (-1082) A allele carrying genotypes (AG + AA) were associated with higher glucose and lower HDL-cholesterol levels. CONCLUSION: Because women with IL-10 (-1082) AA genotype have 3.38-fold increased risk of developing PE according to GG genotype (95% CI 1.21-9.4, P = 0.01), we suggest that IL-10 (-1082) variant A allele is associated with an increased risk of preeclampsia, which is independent from its metabolic effects.

Vascular endothelial growth factor -2578 A/C, -460 T/C and +405 G/C polymorphisms in polycystic ovary syndrome.

OBJECTIVE: Vascular endothelial growth factor (VEGF) may be involved in the physiological regulation of ovarian angiogenesis and pathogenesis of polycystic ovary syndrome (PCOS). VEGF -2578 A/C, -460 T/C and +405 G/C single nucleotide polymorphisms (SNPs) are known to be related to VEGF production. STUDY DESIGN: In order to investigate the possible association between VEGF gene and PCOS susceptibility, we analyzed genotype and allele distributions of above mentioned SNPs in 137 patients with PCOS and 155 healthy women. Differences in genotype distributions and allele frequencies in the cases and controls were compared for statistical significance using the chi(2)-test. Haplotype frequencies were estimated using a contingency chi(2)-test. Mann-Whitney U test was used for the statistics of the clinical and biochemical parameters. RESULTS: No significant association between PCOS and the variant alleles of VEGF -2578 (OR: 0.91, 95% CI=0.65-1.26), -460 (OR: 0.78, 95% CI=0.56-1.08), and +405 (OR: 1.25, 95% CI=0.81-1.93) was observed. However, haplotype analysis demonstrated that the frequency of CTG haplotype, was higher among PCOS compared with controls (p=0.019) and that there is a strong linkage disequilibrium (D'=0.873, r(2)=0.752) between -2578 and -460 polymorphisms. CONCLUSIONS: These preliminary results suggest that the -2578, -460 and +405 SNPs of VEGF gene are not significant risk factors for PCOS development alone. However, because of the high VEGF producer CTG haplotype was more frequent among the PCOS, we suppose that investigated polymorphisms--interacting with other genetic and environmental factors--could play a role in the development of PCOS.

Genetic polymorphisms in DNA repair gene APE1, XRCC1 and XPD and the risk of pre-eclampsia.

OBJECTIVE: Oxidative stress has been postulated as a major contributor to placental hypoperfusion and ischemia in pre-eclampsia (PE). Reactive oxygen species (ROS) generated during placental ischemia can cause oxidative damage to nucleic acids. Base excision repair (BER) and nucleotide excision repair (NER) are major pathways responsible for removing the oxidative DNA damage. Polymorphisms in DNA repair genes may be associated with differences in the repair efficiency of DNA damage. STUDY DESIGN: In order to investigate the possible association between DNA repair genes and PE susceptibility, we analyzed genotype and allele distributions of APE1-148, XRCC1-194, XRCC1-399 and XPD-751 genes in 101 patients with PE and 107 healthy women. Differences in genotype distributions and allele frequencies in the cases and the controls were compared for statistical significance using the chi(2)-test. Haplotype frequencies were estimated using a contingency chi(2)-test. One-way ANOVA and Mann-Whitney U-test were used for the statistics of the clinical and biochemical parameters. RESULTS: No significant association between PE and the variant alleles of APE1 codon 148 (OR: 0.77, 95% CI=0.51-1.15), XRCC1 codon 194 (OR: 0.64, 95% CI=0.30-1.37), XRCC1 codon 399 (OR: 1.16, 95% CI=0.78-1.74) and XPD codon 751 (OR: 1.21, 95% CI=0.81-1.80) was observed. Results of our haplotype analysis demonstrated that there is a high linkage disequilibrium (D': 1.0, r(2)=0.042) between the haplotypes of XRCC1 codon 194 and codon 399 markers. CONCLUSIONS: These preliminary results suggest that the polymorphic variants of APE1-148, XRCC1-194, XRCC1-399, and XPD-751 genes are not significant risk factors for PE development.

Effects of hormone replacement therapy on plasma pro-inflammatory and anti-inflammatory cytokines and some bone turnover markers in postmenopausal women.

OBJECTIVE: The present study was undertaken to evaluate plasma TNFalpha, IL-1beta, IL-10; and urinary hydroxyproline (Hyp) and calcium (Ca) as bone resorption markers in postmenopausal women compared with premenopausal ones; and to assess the effects of HRT upon these cytokines and bone turnover markers. PATIENTS AND METHODS: The study involved 50 healthy postmenopausal women, and 25 healthy premenopausal women (control group). Postmenopausal women were randomly divided into two subgroups: women receiving cycle HRT schedule (0.625 mg conjugated estrogen from days 1 to 28+5 mg medroxyprogesterone acetate from days 18 to 28) for 2 months (n=25); and second subgroup consisted of women receiving continue HRT schedule (0.625 mg conjugated estrogen+2.5 mg medroxyprogesterone acetate from days 1 to 28) for 2 months (n=25). Plasma TNFalpha, IL-1beta and IL-10 concentrations were measured with ELISA kits. Fasting urinary Hyp was measured by Ehrlich's spectrophotometric reaction. Ca was determined by oxalate precipitation and the redox titration procedure. Statistical significance was analysed by Kruskal-Wallis plus post hoc Mann-Whitney U-tests for multiple comparisons, Wilcoxon signed ranks test for paired data, and Pearson correlation test. RESULTS: Compared with premenopausal individuals, postmenopausal women have increased plasma TNFalpha, IL-1beta, IL-10 (p<0.0001, p<0.0001, and p<0.001, respectively); and increased urinary Hyp and Ca concentrations (p<0.05). HRT (both cycle and continue schedules) lead to a significant decrease in TNFalpha, IL-1beta and urinary Hyp concentrations, and has no effect uppon IL-10 levels. HRT reverses increased urinary Hyp and Ca excretion to the premenopausal level. There is a significant positive correlation between pre- and post-HRT IL-1beta levels in both cycle and continue subgroups (r=0.437, p<0.05; and r=0.656, p<0.01, respectively), and between pre-HRT IL-1beta and urinary Ca (r=0.509, p<0.01; and r=0.415, p<0.05). There is a significant negative correlation between post-HRT IL-10 and TNFalpha levels in continue HRT receiving group (r=-0.446, p<0.05). Urinary Hyp in cycle and continue HRT received subgroups are correlated with post-treatment values (r=0.455, p<0.05; and r=0.776, p<0.01). CONCLUSIONS: Plasma TNFalpha, IL-1beta, IL-10; and urinary Hyp and Ca increase with menopause. We suggest that the increase of IL-10 is secondary to the elevation of TNFalpha and IL-1beta and that the increase of IL-10 is a compensatory mechanism, by which this anti-inflammatory cytokine counteracts to pro-inflammatory TNFalpha and IL-1beta, and thus balances their osteoclast activating and oxidative stress-related effects. Two months duration HRT (cycle and continue schedule) lead to the significant decrease in plasma TNFalpha, IL-1beta and urinary Hyp concentrations. HRT reverses increased Hyp and Ca excretion to the premenopausal level. So, HRT, decreasing Th1 cytokines (TNFalpha, IL-1beta) probably improve the aberation of Th1/Th2 balance that is implicated in various pathological conditions. However, because of the relatively small number of participants and short duration of the therapy, further studies are necessary to establish a risk/benefit ratio for HRT to view effects on cytokine pattern and bone metabolism.

Effects of menopause and postmenopausal tibolone treatment on plasma TNFalpha, IL-4, IL-10, IL-12 cytokine pattern and some bone turnover markers.

OBJECTIVE: To asses plasma TNFalpha, IL-4, IL-10, IL-12; urinary hydroxyproline (Hyp) and calcium as bone resorption markers in healthy postmenopausal women compared with premenopausal ones, and to observe the effect of tibolone (2.5mg/day for 6 months) upon above mentioned parameters. PATIENTS AND METHODS: The study involved 24 healthy postmenopausal women (study group) and 25 premenopausal women (control group). Plasma TNFalpha, IL-4, IL-10 and IL-12 concentrations were measured using ELISA kits. Fasting urinary Hyp was measured by Ehrlich's spectrophotometric reaction. Calcium was determined by oxalate precipitation and the redox titration procedure. Statistical significance was analysed by the Mann-Whitney U-test for unpaired data, Wilcoxon Signed Rank test for paired data, and Pearson correlation test. RESULTS: Postmenopausal women (both before and after tibolone treatment) have increased (p<0.001) plasma TNFalpha, IL-4, IL-10, IL-12; and increased urinary Hyp (p<0.05) and calcium (p<0.001) concentrations in comparison with premenopausal individuals. Tibolone treatment has no effect on reversing the increased postmenopausal plasma TNFalpha, IL-4, IL-10 and IL-12, but decreases urinary Hyp and calcium to premenopausal levels. There is a weak positive correlation (r=0.532; p<0.05) between TNFalpha and IL-4 levels in postmenopausal women. CONCLUSIONS: The results show that plasma TNFalpha, IL-4, IL-10, IL-12, urinary Hyp and calcium increase with menopause. The increase of anti-inflammatory IL-10, IL-12 and especially IL-4 is probably a compensatory mechanism, by which these cytokines counteract to pro-inflammatory TNFalpha, and thus balance its osteoclast activating and oxidative stress inducing effects. Tibolone is successful in decreasing of bone resorption markers (urinary Hyp and calcium), but has no effect on reversing the impact of menopause on plasma TNFalpha, as well as IL-4, IL-10, IL-12. The last effect probably is related with progestogenic and androgenic properties of tibolone. Clearly, further studies are necessary to establish a risk/benefit ratio for tibolone in view of its effects on bone turnover as a new hormone replacement rationale.

Effects of menopause and tibolone on antioxidants in postmenopausal women.

BACKGROUND: Oxidative stress has been implicated in the pathogenesis of ageing and menopause, and can arise through the increased production of lipid peroxides and/or a deficiency of antioxidant defence. AIM: To investigate the effects of the menopause and tibolone treatment (2.5 mg/day for six months) on plasma antioxidants and lipid peroxidation. METHODS: Plasma concentrations of ascorbic acid, alpha-tocopherol, total thiol groups, caeruloplasmin, erythrocyte glutathione (GSH) and malondialdehyde (MDA) were measured in 24 postmenopausal and 24 premenopausal healthy women. RESULTS: Data analysis indicates a significant decrease in plasma ascorbic acid, alpha-tocopherol, total thiol groups, [corrected]erythrocyte GSH and a significant increase in lipid peroxides (expressed as MDA concentrations) in postmenopausal women. There was no significant difference between control and study groups in the mean plasma caeruloplasmin concentrations. It was found that there is a significant increase in alpha-tocopherol and significant decrease in lipid peroxide concentrations in postmenopausal after tibolone treatment. CONCLUSIONS: The menopause is associated with an increase in oxidative stress and a decrease of some antioxidants, such as ascorbic acid, alpha-tocopherol, total thiols and erythrocyte GSH. Tibolone treatment leads to a decrease in concentrations of plasma lipid peroxide, probably by stimulating direct and indirect mechanisms of tocopherol regeneration and increasing plasma concentrations of vitamin E. However, due to the relatively small numbers involved this study can be regarded as a pilot. Further studies performed on a larger scale are necessary to establish the exact mechanisms of tibolone in inhibiting oxidative stress in postmenopausal women.

Effects of tibolone on endogenous nitric oxide (nitrite/nitrate levels) in postmenopausal women.

OBJECTIVE: To observe the effects of hormone replacement therapy with 2.5 mg/day tibolone for 6 months upon plasma nitrite/nitrate (end products of nitric oxide metabolism) in postmenopausal women. PATIENTS AND METHODS: The study involved 24 healthy postmenopausal women treated with tibolone (2.5 mg/day for 6 months) and 20 postmenopausal women who received placebo. Plasma nitrite/nitrate levels were measured with the Griess reaction. Statistical significance was analyzed by the Mann-Whitney U test and Pearson correlation analysis. RESULTS: The mean baseline concentrations of nitrite/nitrate were similar in both treated and placebo groups. Tibolone treatment decreased plasma nitrite/nitrate levels. CONCLUSIONS: We suggest that because of its androgenic and progestogenic actions, tibolone diminishes nitrite/nitrate levels. Also our data provide evidence for the existence of increased (1/3 of subjects, n = 8) and reduced (2/3 of subjects, n = 16) nitrite/nitrate levels in response to tibolone treatment. Clearly, further studies are necessary to establish a risk/benefit ratio for tibolone in view of its effects on nitric oxide metabolism.

Effects of tibolone on thromboxane B(2) levels in postmenopausal women.

This study was carried out in 16 premenopausal (control) and 24 postmenopausal women (study group) to investigate the effect of menopause and tibolone treatment (2.5 mg/day for 6 months) on plasma thromboxane B(2) (TxB(2)), a well-known vasoconstrictor and stimulator of platelet aggregation. The TxB(2) levels were measured using [(125)I] RIA kit. Statistical significance was analyzed by Student's t test for paired and unpaired data, and Pearson's correlation analysis. Plasma TxB(2) concentrations of postmenopausal women were higher than those of premenopausal women. Tibolone treatment decreased plasma TxB(2) in postmenopausal women. There was no correlation between TxB(2) and blood pressure and heart rate. It was concluded that tibolone, decreasing the plasma concentrations of TxB(2), might have beneficial effects on prostaglandin metabolism and thus reduce the risk of cardiovascular disease.