The -597 G-->A and -174 G-->C polymorphisms in the promoter of the IL-6 gene are associated with hyperandrogenism

Research progress on the role of macrophages in acne and regulation by natural plant products

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

Association of Insulin Resistance and Elevated Androgen Levels with Polycystic Ovarian Syndrome (PCOS): A Review of Literature

The polycystic ovary syndrome (PCOS) is the disease featured by elevated levels of androgens, ovulatory dysfunction, and morphological abnormalities. At reproductive stage of women, the rate of PCOS occurrence is measured as 6–10% and the prevalence rate may be double. There are different pathophysiological factors involved in PCOS, and they play a major role in various abnormalities in individual patient. It is clear that there is noteworthy elevation of androgen in PCOS, causing substantial misery and infertility problems. The overexposure of androgen is directly linked with insulin resistance and hyperinsulinaemia. It has been reported previously that PCOS is related to cardiac metabolic miseries and potently increases the risk of heart diseases. Endometrial cancer is also a serious concern which is reported with exceedingly high incidence in women with PCOS. However, the overexposure of androgen has direct and specific influence on the development of insulin resistance. Although many factors are involved, resistance to the insulin and enhanced level of androgen are considered the major causes of PCOS. In the present review, we have focused on the pathophysiology and major revolutions of insulin resistance and excessive levels of androgen in females with PCOS.

IL-34 was high in serum of women with polycystic ovary syndrome and may function as potential diagnostic biomarker and therapeutic target

BACKGROUND

Polycystic ovary syndrome (PCOS) is one of the most prevalent endocrine disorders in females of reproductive age, with a prevalence of 20%-33% in the general population. Interleukin (IL)-34 is a recently explored proinflammatory cytokine and is an important modulator in different disease types. However, the function of IL-34 in PCOS has yet to be investigated.

OBJECTIVE

The purpose of this study was to determine the IL-34 serum level in women with PCOS and to compare it to that of a relatively healthy control group. Focusing on its relationship with IL-6, TNF-α, and IL-1β and homeostatic model assessment for insulin resistance (HOMA-IR), triglyceride, and low-density lipoprotein cholesterol (LDL-C).

MATERIALS AND METHODS

In this study, blood samples were obtained from 100 women with PCOS and 100 healthy control women for the purpose of estimating their serum levels of IL-34, IL-6, TNF-α, and IL-1β using the enzyme-linked immunosorbent assay technique.

RESULTS

Serum levels of IL-34, IL-6, TNF-α, and IL-1β were all higher in PCOS women than in healthy controls, and the difference was highly statistically significant. Serum IL-34 concentration was positively correlated with IL-6, TNF-α, and IL-1β concentration. Additionally, serum concentrations of IL-34 were positively correlated with HOMA-IR, triglyceride, and LDL-C.

CONCLUSION

When compared to normal women, IL-34, IL-6, TNF-α, and IL-1β levels were highly statistically significant in PCOS, and these high levels were associated with other cytokines (IL-6, TNF-α, and IL-1β), HOMA-IR, triglyceride, and LDL-C.

PCOS and Depression: Common Links and Potential Targets

PCOS or polycystic ovary syndrome is a common endocrine disorder that occurs during the reproductive age in females. It manifests in the form of a wide range of symptoms including (but not limited to) hirsutism, amenorrhea, oligomenorrhea, obesity, acne vulgaris, infertility, alopecia, and insulin resistance. The incidence of depression in PCOS population is increasing as compared to the general population. Increased depression in PCOS significantly alters the quality of life (QOL) of affected females. Also, self-esteem is found to be low in both depression and PCOS. The loss in self-esteem in such patients can be largely attributed to the associated factors including (but not limited to) obesity, acne, androgenic alopecia, and hirsutism. The reason behind the occurrence of depression in PCOS remains elusive to date. Literature suggests that there is an overlap of clinical symptoms between depression and PCOS. As the symptoms overlap, there is a possibility of common associations between depression, PCOS, and PCOS-associated abnormalities including insulin resistance (IR), obesity, CVD, and androgen excess. Studies demonstrate that depression is an inflammatory disorder marked with increased levels of inflammatory markers. On the other hand, PCOS is also regarded as a pro-inflammatory state that is characterized by increased levels of pro-inflammatory markers. Thus, there is a possibility of an inflammatory relationship existing between depression and PCOS. It is also possible that the inflammatory markers in PCOS can cross the blood-brain barrier (BBB) leading to the development of depression. Through the present review, we have attempted to shed light on common associations/shared links between depression and PCOS with respect to the levels of cortisol, androgen, vitamin D, neurotransmitters, monoaminoxidase (MAO), and insulin-like growth factor-1 (IGF-1). Tracking down common associations between depression and PCOS will help find potential drug therapies and improve the QOL of females with depression in PCOS.

Macrophages: an indispensable piece of ovarian health

Macrophages are the most abundant immune cells in the ovary. In addition to their roles in the innate immune system, these heterogeneous tissue-resident cells are responsive to tissue-derived signals, adapt to their local tissue environment, and specialize in unique functions to maintain tissue homeostasis. Research in the past decades has established a strong link between macrophages and various aspects of ovarian physiology, indicating a pivotal role of macrophages in ovarian health. However, unlike other intensively studied organs, the knowledge of ovarian macrophages dates back to the time when the heterogeneity of ontogeny, phenotype, and function of macrophages was not fully understood. In this review, we discuss the evolving understanding of the biology of ovarian tissue-resident macrophages, highlight their regulatory roles in normal ovarian functions, review the association between certain ovarian pathologies and disturbed macrophage homeostasis, and finally, discuss the technologies that are essential for addressing key questions in the field.

The Role of Chronic Inflammation in Polycystic Ovarian Syndrome-A Systematic Review and Meta-Analysis

Although the current literature associates polycystic ovarian syndrome (PCOS) with chronic inflammation, the evidence for this link remains inconclusive and its causal nature remains unclear. The purpose of this systematic review was to assess the inflammatory status in PCOS women and to determine whether it is related to PCOS or to its associated adiposity. We searched electronic databases including PUBMED, EMBASE and MEDLINE, SCOPUS, DynaMed plus, TRIP, ScienceDirect and Cochrane Library, for studies investigating C-reactive protein (CRP) and other inflammatory makers in PCOS women versus healthy controls. Quality and risk of bias for selected studies were assessed using the modified Newcastle-Ottawa scale. CRP data were extracted and pooled using RevMan for calculation of the standardized mean difference (SMD) and 95% confidence interval (CI). Eighty-five eligible studies were included in the systematic review, of which 63 were included in the meta-analysis. Pooled analysis of the 63 studies revealed significantly higher circulating CRP in PCOS women (n = 4086) versus controls (n = 3120) (SMD 1.26, 95%CI, 0.99, 1.53). Sensitivity meta-analysis of 35 high quality studies including non-obese women showed significantly higher circulating CRP in PCOS women versus controls (SMD 1.80, 95%CI, 1.36, 2.25). In conclusion, circulating CRP is moderately elevated in PCOS women independent of obesity, which is indicative of low-grade chronic inflammation.

Comparative Evaluation of Biomarkers of Inflammation Among Indian Women With Polycystic Ovary Syndrome (PCOS) Consuming Vegetarian vs. Non-vegetarian Diet

Background: Sub-inflammation and insulin resistance characterize women with PCOS. Data on dietary modulation of inflammation among PCOS women is scant, particularly from Indian subcontinent. The present study aimed to assess the effect of plant based vs. animal origin diets on serum markers of inflammation (primary outcome measure). Methods: This observational case-control study compared age and BMI matched PCOS and apparently healthy women from two populations following different dietary practices. The vegetarian women from New-Delhi (n = 82 PCOS and n = 179 healthy) and non-vegetarian women from Srinagar (n = 62 PCOS and n = 141 healthy) formed the groups. Using a uniform methodology, detailed clinical, biochemical, hormonal, and inflammatory marker assessment was undertaken. Results: The mean age of the overall cohort was 26.23 ± 4.59 years with a mean BMI of 24.39 ± 3.72 kg/m2. Overall pro-inflammatory markers (TNF-α, IL-6, IL-1β, hs-CRP and serum resistin) were significantly higher (p ≤ 0.05) and anti-inflammatory markers (IL-10 and adiponectin) were lower among women with PCOS than healthy subjects. On comparing vegetarian women with non-vegetarians, higher daily calorie intake (1895.46 ± 258.19 vs. 1860.13 ± 323.96 Kcal) with a higher protein and fat and lower carbohydrate intake was recorded in the latter, although the percent energy derived from carbohydrates was higher among vegetarians. Clinical and biochemical parameters were comparable among the groups except mFG score, total serum testosterone and serum lipid levels which were higher among non-vegetarian women as compared to their vegetarian counterparts from both categories (PCOS and healthy). Interestingly, vegetarian women with PCOS and healthy women had higher serum pro-inflammatory and lower anti-inflammatory markers compared to their non-vegetarian counterparts. Conclusion: Women with PCOS consuming Indian vegetarian diet have higher pro-inflammatory and lower anti-inflammatory marker levels than their age and BMI matched healthy non-vegetarian counterparts. This interesting observation can be attributed to the dietary composition, among other factors and needs confirmation from well-designed randomized studies on a larger cohort. Clinical Trial Registration: The study was registered with CTRI database under registration number CTRI/2013/09/003996.

Moderate increases in daily step count are associated with reduced IL6 and CRP in women with PCOS

Aims Physical activity has been proposed to be an effective non-pharmacological method of reducing systemic inflammation and therefore may prove particularly efficacious for women with polycystic ovary syndrome (PCOS) who have been shown to have high levels of inflammation and an increased risk of type 2 diabetes (T2DM) and cardiovascular disease (CVD). Therefore, the aim of the present study was to assess whether modest changes in daily step count could significantly reduce levels of inflammatory markers in women with PCOS. Subjects and Methods Sixty-five women with PCOS were assessed at baseline and again at 6 months. All had been provided with an accelerometer and encouraged to increase activity levels. Multivariate linear regression analyses (adjusted for age, ethnicity, baseline step count, change in BMI and change in accelerometer wear-time) were used to assess changes in daily step count against clinical and research biomarkers of inflammation, CVD and T2DM. Results Mean step count/day at baseline was 6337 (±270). An increase in step count (by 1000 steps) was associated with a 13% reduction in IL6 (β: -0.81 ng/L; 95% CI, -1.37, -0.25, P = 0.005) and a 13% reduction in CRP (β: -0.68 mg/L; 95% CI, -1.30, -0.06, P = 0.033). Additionally, there was a modest decrease in BMI (β: 0.20 kg/m2; 95% CI, -0.38, -0.01, P = 0.038). Clinical markers of T2DM and CVD were not affected by increased step count. Conclusions Modest increases in step count/day can reduce levels of inflammatory markers in women with PCOS, which may reduce the future risk of T2DM and CVD.

Autocrine Loop Involving IL-6 Family Member LIF, LIF Receptor, and STAT4 Drives Sustained Fibroblast Production of Inflammatory Mediators

Fibroblasts are major contributors to and regulators of inflammation and dominant producers of interleukin-6 (IL-6) in inflammatory diseases like rheumatoid arthritis. Yet, compared to leukocytes, the regulation of inflammatory pathways in fibroblasts is largely unknown. Here, we report that analyses of genes coordinately upregulated with IL-6 pointed to STAT4 and leukemia inhibitory factor (LIF) as potentially linked. Gene silencing revealed that STAT4 was required for IL-6 transcription. STAT4 was recruited to the IL-6 promoter after fibroblast activation, and LIF receptor (LIFR) and STAT4 formed a molecular complex that, together with JAK1 and TYK2 kinases, controlled STAT4 activation. Importantly, a positive feedback loop involving autocrine LIF, LIFR, and STAT4 drove sustained IL-6 transcription. Besides IL-6, this autorine loop also drove the production of other key inflammatory factors including IL-8, granulocyte-colony stimulating factor (G-CSF), IL-33, IL-11, IL-1α, and IL-1β. These findings define the transcriptional regulation of fibroblast-mediated inflammation as distinct from leukocytes.

Endolysosomal trafficking of viral G protein-coupled receptor functions in innate immunity and control of viral oncogenesis

The ubiquitin-proteasome system degrades viral oncoproteins and other microbial virulence factors; however, the role of endolysosomal degradation pathways in these processes is unclear. Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma, and a constitutively active viral G protein-coupled receptor (vGPCR) contributes to the pathogenesis of KSHV-induced tumors. We report that a recently discovered autophagy-related protein, Beclin 2, interacts with KSHV GPCR, facilitates its endolysosomal degradation, and inhibits vGPCR-driven oncogenic signaling. Furthermore, monoallelic loss of Becn2 in mice accelerates the progression of vGPCR-induced lesions that resemble human Kaposi's sarcoma. Taken together, these findings indicate that Beclin 2 is a host antiviral molecule that protects against the pathogenic effects of KSHV GPCR by facilitating its endolysosomal degradation. More broadly, our data suggest a role for host endolysosomal trafficking pathways in regulating viral pathogenesis and oncogenic signaling.

A possible role for AMP-activated protein kinase activated by metformin and AICAR in human granulosa cells

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are generally insulin- resistant and are consequently often treated with metformin. We investigated the effect of metformin and AICAR on the AMP-activated protein kinase (AMPK) pathway.

METHODS

We evaluated the effects of 5-amino-imidazole-4-carboxyamide-1- beta-D-ribofuranoside (AICAR) and metformin on tumor necrosis factor (TNF)-alpha- stimulated chemokine production in human granulosa cells. The phosphorylations of AMPK, I-kappaB, 4E-BP-1, p70S6K were analyzed by western immunoblotting.

RESULTS

AICAR and metformin markedly reduced the IL-8 and GROalpha production induced by TNF-alpha. AICAR and metformin also reduced the TNF-alpha-induced phosphorylation of I-kappaB. The phosphorylations of I-kappaB, 4EBP-1, p70S6K were inhibited via an AMPK-dependent signal transduction.

CONCLUSIONS

These results suggest that metformin promotes granulosa cell function by reducing a TNF-alpha- and chemokine-mediated inflammatory reaction through an AMPK-dependent pathway. These finding may have implications for metformin's actions during the treatment of PCOS with metformin.

Polycystic Ovary Syndrome: Important Underrecognised Cardiometabolic Risk Factor in Reproductive-Age Women

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age. Although PCOS is diagnosed exclusively based on reproductive criteria, it is also a metabolic disorder. Insulin resistance, impaired glucose tolerance, type 2 diabetes mellitus, obesity, and dyslipidemia are more common in women with PCOS than in age-comparable women without PCOS. Many of the metabolic abnormalities that manifest in PCOS are worsened by the concurrent incidence of obesity. However, some of these metabolic perturbations occur even in lean women with PCOS and therefore are rightfully recognized as intrinsic to PCOS. The intrinsic factors that produce these metabolic disturbances are reviewed in this paper. The consequences of obesity and the other metabolic aberrations are also discussed. The metabolic perturbations in PCOS patients lead to chronic low-grade inflammation and to cardiovascular impairments that heighten the risk of having cardiovascular disease. Even though many studies have shown an elevation in surrogate biomarkers of cardiovascular disease in PCOS women, it is still not clear to what extent and magnitude the elevation precipitates more frequent and earlier events.

An interleukin-6 gene promoter polymorphism is associated with polycystic ovary syndrome in South Indian women

PURPOSE

Polycystic ovary syndrome (PCOS) is a most common endocrine disorder of reproductive age women. Interleukin-6 is involved in the pathophysiological characteristics associated with polycystic ovary syndrome (PCOS). The-174 G/C IL-6 gene promoter region single nucleotide polymorphism (SNP) may influence or modulate gene function and/or transcriptional efficiency. The current study was aimed to evaluate the association between IL-6 gene -174 G/C promoter polymorphism and Polycystic Ovary Syndrome in South Indian women.

METHODS

In the present study, we examined the genotypic and allele distribution among the PCOS patients (n = 104) and controls (n = 156). The genotypes of IL-6 -174 G/C SNP were analyzed by polymerase chain reaction (PCR) and sequencing analysis. The allele frequency and genotype distributions of cases and controls were analyzed using Fisher's exact test.

RESULTS

The genotype frequencies observed among the 104 cases and 156 controls were G/G 66.3 % and 49.4 %, G/C 29.8 % and 46.8 %, and C/C 3.8 % and 3.8 % (OR: 1.6226, CI: 1.0574-2.4899). The G and C allele frequencies were 81.25 % and 72.8 %, and 18.75 % and 27.2 %, respectively. The genotype and allele distribution revealed significant differences between PCOS patients and controls (all P values < 0.05).

CONCLUSION

Our findings showed a significant statistical association between IL-6 -174 G/C SNP and PCOS risk in South Indian women. The 'G' allele frequency influences significantly higher in PCOS patients than controls. However, the exact mechanism by which 'G' allele frequency influence PCOS patients is yet to be determined.

Cardiometabolic aspects of the polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age and is associated with various metabolic perturbations, in addition to chronic anovulation and factors related to androgen excess. In general, women live longer than men and develop cardiovascular disease at an older age. However, women with PCOS, as compared with age- and body mass index-matched women without the syndrome, appear to have a higher risk of insulin resistance, hyperinsulinemia, glucose intolerance, dyslipidemia, and an increased prothrombotic state, possibly resulting in a higher rate of type 2 diabetes mellitus, fatty liver disease, subclinical atherosclerosis, vascular dysfunction, and finally cardiovascular disease and mortality. Further alterations in PCOS include an increased prevalence of sleep apnea, as well as various changes in the secretion and/or function of adipokines, adipose tissue-derived proinflammatory factors and gut hormones, all of them with direct or indirect influences on the complex signaling network that regulates metabolism, insulin sensitivity, and energy homeostasis. Reviews on the cardiometabolic aspects of PCOS are rare, and our knowledge from recent studies is expanding rapidly. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge, focusing on the alterations of cardiometabolic factors in women with PCOS. Further insight into this network of factors may facilitate finding therapeutic targets that should ameliorate not only ovarian dysfunction but also the various cardiometabolic alterations related to the syndrome.

Inflammation in Polycystic Ovary Syndrome: underpinning of insulin resistance and ovarian dysfunction

Chronic low-grade inflammation has emerged as a key contributor to the pathogenesis of Polycystic Ovary Syndrome (PCOS). A dietary trigger such as glucose is capable of inciting oxidative stress and an inflammatory response from mononuclear cells (MNC) of women with PCOS, and this phenomenon is independent of obesity. This is important because MNC-derived macrophages are the primary source of cytokine production in excess adipose tissue, and also promote adipocyte cytokine production in a paracrine fashion. The proinflammatory cytokine tumor necrosis factor-α (TNFα) is a known mediator of insulin resistance. Glucose-stimulated TNFα release from MNC along with molecular markers of inflammation are associated with insulin resistance in PCOS. Hyperandrogenism is capable of activating MNC in the fasting state, thereby increasing MNC sensitivity to glucose; and this may be a potential mechanism for promoting diet-induced inflammation in PCOS. Increased abdominal adiposity is prevalent across all weight classes in PCOS, and this inflamed adipose tissue contributes to the inflammatory load in the disorder. Nevertheless, glucose ingestion incites oxidative stress in normal weight women with PCOS even in the absence of increased abdominal adiposity. In PCOS, markers of oxidative stress and inflammation are highly correlated with circulating androgens. Chronic suppression of ovarian androgen production does not ameliorate inflammation in normal weight women with the disorder. Furthermore, in vitro studies have demonstrated the ability of pro-inflammatory stimuli to upregulate the ovarian theca cell steroidogenic enzyme responsible for androgen production. These findings support the contention that inflammation directly stimulates the polycystic ovary to produce androgens.

Understanding polycystic ovarian syndrome pathogenesis: an updated of its genetic aspects

Polycystic ovary syndrome (PCOS) is the most frequent cause of female infertility. It is also characterized by metabolic defects that raise the risk for cardiovascular disease. Despite the progress in the definition of the clinical aspects of the syndrome, only very few definite data are available about the ethiopathogenetic mechanisms that subtend PCOS. It is likely that the PCOS phenotype derives from the interaction between environmental and genetic factors. While environmental factors have easily been investigated, the individuation of the genetic factors seem to be more complex. Indeed, PCOS appears to be inherited as a complex, polygenic trait. Several family studies have been conducted with the aim to clarify the genetic aspects of PCOS, but their findings are often conflicting and not conclusive.Moreover, it is difficult to establish with certainty which genes are involved and their effective role in the development of the syndrome because in PCOS, genetic analysis is hampered by low fecundity, lack of a male phenotype, absence of an animal model, and dissimilarity of the diagnostic criteria used to select the patients. Since multiple biochemical pathways are implicated in PCOS pathogenesis, genes of steroid hormone metabolism, gonadotropin release and action, insulin secretion and action, adipose tissue metabolism and others have been investigated. Nevertheless, none of them seems to play a key role in the ethiopathogenesis of PCOS. This article reviews the large body of literature generated to support the presence of genetic abnormalities in PCOS women by taking in consideration the most important studies regarding PCOS candidate genes.

The Genetic Basis of the Polycystic Ovary Syndrome: A Literature Review Including Discussion of PPAR-gamma

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of the women of reproductive age. Familial clustering of PCOS has been consistently reported suggesting that genetic factors play a role in the development of the syndrome although PCOS cases do not exhibit a clear pattern of Mendelian inheritance. It is now well established that PCOS represents a complex trait similar to type-2 diabetes and obesity, and that both inherited and environmental factors contribute to the PCOS pathogenesis. A large number of functional candidate genes have been tested for association or linkage with PCOS phenotypes with more negative than positive findings. Lack of universally accepted diagnostic criteria, difficulties in the assignment of male phenotype, obscurity in the mode of inheritance, and particularly small sample size of the study populations appear to be major limitations for the genetic studies of PCOS. In the near future, utilizing the genome-wide scan approach and the HapMap project will provide a stronger potential for the genetic analysis of the syndrome.

Obesity and the pubertal transition in girls and boys

Childhood obesity has become a major health concern in recent decades, especially with regard to metabolic abnormalities that impart a high risk for future cardiovascular disease. Recent data suggest that excess adiposity during childhood may influence pubertal development as well. In particular, excess adiposity during childhood may advance puberty in girls and delay puberty in boys. Obesity in peripubertal girls may also be associated with hyperandrogenemia and a high risk of adolescent polycystic ovary syndrome. How obesity may perturb various hormonal aspects of pubertal development remains unclear, but potential mechanisms are discussed herein. Insulin resistance and compensatory hyperinsulinemia may represent a common thread contributing to many of the pubertal changes reported to occur with childhood obesity. Our understanding of obesity's impact on pubertal development is in its infancy, and more research into pathophysiological mechanisms and longer-term sequelae is important.

Circulating inflammatory markers in polycystic ovary syndrome: a systematic review and metaanalysis

OBJECTIVE

To perform a review and metaanalysis of the studies evaluating the status of serum inflammatory markers in women with polycystic ovary syndrome (PCOS).

DESIGN

Systematic review and metaanalysis of articles published in English before January 2010 and identified using the PubMed search engine.

SETTING

Academic hospital.

PATIENT(S)

Women with PCOS and appropriate controls.

INTERVENTION(S)

Measurement of serum concentrations of inflammatory markers by high-sensitivity techniques.

MAIN OUTCOME MEASURE(S)

Metaanalyses of the mean difference in serum C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations among patients with PCOS and appropriate controls, applying random-effects models to limit interstudy variability, and using appropriate estimates of evidence dissemination bias.

RESULT(S)

Metaanalysis of the 31 articles meeting inclusion criteria showed that circulating CRP was 96% higher in women with PCOS compared to controls (95% confidence interval, 71%-122%; z = 7.32) without evidence of dissemination bias (Egger's regression intercept, 0.45; 95% confidence interval, -2.30 to 3.21). These findings persisted after excluding five studies with mismatches in body mass, frequency of obesity, or both, between women with PCOS and controls. Metaanalyses involving 10 studies of IL-6, and nine studies of TNF-α revealed no statistically significant differences between PCOS and controls.

CONCLUSION(S)

Women with PCOS exhibit an elevation in circulating CRP that is independent of obesity. This finding corroborates existing molecular evidence of the chronic low-grade inflammation that may underpin the pathogenesis of this disorder.

Genome-wide association study identifies susceptibility loci for polycystic ovary syndrome on chromosome 2p16.3, 2p21 and 9q33.3

Polycystic ovary syndrome (PCOS) is a common metabolic disorder in women. To identify causative genes, we conducted a genome-wide association study (GWAS) of PCOS in Han Chinese. The discovery set included 744 PCOS cases and 895 controls; subsequent replications involved two independent cohorts (2,840 PCOS cases and 5,012 controls from northern Han Chinese; 498 cases and 780 controls from southern and central Han Chinese). We identified strong evidence of associations between PCOS and three loci: 2p16.3 (rs13405728; combined P-value by meta-analysis P(meta) = 7.55 × 10⁻²¹, odds ratio (OR) 0.71); 2p21 (rs13429458, P(meta) = 1.73 × 10⁻²³, OR 0.67); and 9q33.3 (rs2479106, P(meta) = 8.12 × 10⁻¹⁹, OR 1.34). These findings provide new insight into the pathogenesis of PCOS. Follow-up studies of the candidate genes in these regions are recommended.

Body iron stores and glucose intolerance in premenopausal women: role of hyperandrogenism, insulin resistance, and genomic variants related to inflammation, oxidative stress, and iron metabolism

OBJECTIVE Increased serum ferritin levels and iron stores may be involved in the development of abnormal glucose tolerance in women presenting with obesity and/or polycystic ovary syndrome (PCOS). We aimed to study the determinants of serum ferritin levels in premenopausal women among indexes of insulin resistance, adiposity, hyperandrogenism, and genotypes pertaining to inflammation, oxidative stress, and iron metabolism. RESEARCH DESIGN AND METHODS A total of 257 premenopausal women, classified depending on the presence or absence of PCOS, obesity, and/or abnormal glucose tolerance, underwent a complete metabolic evaluation, serum ferritin, haptoglobin, and C-reactive protein (CRP) measurements, and genotyping for proinflammatory and prooxidant variants and mutations in the HFE gene. RESULTS Serum ferritin concentrations were increased in women presenting with PCOS and/or abnormal glucose tolerance, independent of obesity. A stepwise multivariate linear regression analysis (R(2) = 0.18, P < 0.0001) retained menstrual dysfunction (beta = 0.14, P = 0.035), free testosterone (beta = 0.14, P = 0.052), insulin sensitivity index (beta = -0.12, P = 0.012), the His63Asp variant in HFE (beta = 0.16, P = 0.008), and abnormal glucose tolerance (beta = 0.15, P = 0.015) as significant predictors of the logarithm of ferritin levels, whereas CRP, haptoglobin, waist-to-hip ratio, or variants in the TNFalpha, TNFRSF1B, IL6, IL6ST, IL6Ralpha, PON1, and HFE Cys282Tyr mutation exerted no influence. CONCLUSIONS Androgen excess (partly because of hyperandrogenemia and partly because of menstrual dysfunction), insulin resistance, abnormal glucose tolerance, and the HFE His63Asp variant correlate with ferritin levels in premenopausal women.

Cytokine SNPs: Comparison of allele frequencies by race and implications for future studies

The role of inflammation is being considered in chronic diseases. Previous studies have examined SNPs in a few key inflammatory genes and have included small numbers of African American participants. Variation in the frequencies of inflammatory pathway SNPs may help to explain racial disparities in disease risk. Through a population-based study of 103 African American and 380 Caucasian unrelated, healthy women, we examined the relationships between race and allele frequencies of 70 cytokine and cytokine receptor SNPs. The associations between genotypic and haplotype frequencies and race were also analyzed. Allelic frequencies for 52 out of the 70 SNPs meeting criteria for analysis differed significantly by race. Of the 32 pro-inflammatory and 20 anti-inflammatory SNPs for which the allele frequencies varied significantly by race, variant allele frequency differences between Caucasians and African Americans ranged between 6-37% and 7-53% for pro-inflammatory SNPs and anti-inflammatory SNPs, respectively. Our findings suggest that while allele frequencies do vary by race, racial groups are not simplistically represented by a pro-inflammatory or anti-inflammatory genetic profile. Given the racial variability in allele frequencies in inflammatory gene SNPs, studies examining the association between these SNPs and disease should at least incorporate self-reported race in their analyses.

Functional genetic polymorphisms and female reproductive disorders: Part I: Polycystic ovary syndrome and ovarian response

BACKGROUND

The identification of polymorphisms associated with a disease can help to elucidate its pathogenesis, and this knowledge can be used to improve prognosis for women with a particular disorder, such as polycystic ovary syndrome (PCOS). Since an altered response to ovarian stimulation is also a characteristic of the disease, further knowledge about its aetiology could help in defining the parameters that determine the response of an individual to ovarian stimulation.

METHODS

PubMed and EMBASE databases were systematically searched for gene association studies published until the end of August 2007, using search criteria relevant to PCOS and ovarian response to stimulation. Data from additional papers identified through hand searches were also included; 139 publications were reviewed.

RESULTS

Several genes involved in ovarian function and metabolism are associated with increased susceptibility to PCOS, but none is strong enough to correlate alone with susceptibility to the disease, or response to therapy. A single-nucleotide polymorphism in exon 10 of the FSH receptor (FSHR) gene, FSHR p.N680S, was consistently identified as having a significant association with ovarian response to FSH.

CONCLUSIONS

No consistent association between gene polymorphism and PCOS could be identified. The FSHR gene may play a significant role in the success of ovarian stimulation, and can be used as a marker to predict differences in FSHR function and ovarian response to FSH. Genotyping the FSHR p.N680S polymorphism may provide a means of identifying a population of poor responders before in vitro fertilization procedures are initiated.

The impact of interleukin-6 promoter -597/-572/-174genotype on interleukin-6 production after lipopolysaccharide stimulation

Interleukin (IL)-6 is a pleiotropic cytokine, produced by different cells. There is accumulating evidence that IL-6 promoter polymorphisms impact substantially on various diseases and we identified kidney transplant recipients carrying the IL-6 GGG/GGG (-597/-572/-174)genotype to have superior graft survival. To prove a functional impact on gene expression, we analysed systematically IL-6 production in healthy individuals with respect to the IL-6 (-597/-572/-174)genotype. IL-6 was determined in 100 healthy blood donors at protein and mRNA levels upon specific stimulation in monocytes and T lymphocytes under whole blood conditions. GGG/GGG individuals showed a lower IL-6 secretion upon lipopolysaccharide (LPS)-stimulation versus all others (P = 0.039). This link was even stronger when (-597) and (-174)GG genotypes were reanalysed separately (P = 0.008, P = 0.017). However, we found neither a difference at the mRNA level or percentage of CD14(+) cells nor after T cell stimulation. We found evidence for the IL-6 (-597/-572/-174)genotype to affect IL-6 synthesis, i.e. lower levels of IL-6 protein upon LPS-stimulation in GGG/GGG individuals. Further studies are needed in kidney transplant recipients to investigate the potential link between the GGG/GGG genotype and graft survival. In line with this, determination of the genetic risk profiles might be promising to improve the transplant outcome in the individual patient.

Interleukin-6-Related Genotypes, Body Mass Index, and Risk of Multiple Myeloma and Plasmacytoma

Interleukin-6 (IL-6) promotes normal plasma cell development and proliferation of myeloma cells in culture. We evaluated IL-6 genotypes and body mass index (BMI) in a case-control study of multiple myeloma and plasmacytoma. DNA samples and questionnaires were obtained from incident cases of multiple myeloma (n = 134) and plasmacytoma (n = 16; plasma cell neoplasms) ascertained from the Los Angeles County population-based cancer registry and from siblings or cousins of cases (family controls, n = 112) and population controls (n = 126). Genotypes evaluated included IL-6 promoter gene single nucleotide polymorphisms (SNP) at positions -174, -572, and -597; one variable number of tandem repeats (-373 A(n)T(n)); and one SNP in the IL-6 receptor (IL-6ralpha) gene at position -358. The variant allele of the IL-6 promoter SNP -572 was associated with a roughly 2-fold increased risk of plasma cell neoplasms when cases were compared with family [odds ratio (OR), 1.8; 95% confidence interval (95% CI), 0.7-4.7] or population controls (OR, 2.4; 95% CI, 1.2-4.7). The -373 9A/9A genotype was associated with a decreased risk compared with the most common genotype (OR for cases versus family controls, 0.4; 95% CI, 0.1-1.7; OR for cases versus population controls, 0.3; 95% CI, 0.1-0.9). No other SNPs were associated with risk. Obesity (BMI >or= 30 kg/m(2)) increased risk nonsignificantly by 40% and 80% when cases were compared with family controls or population controls, respectively, relative to persons with a BMI of <25 kg/m(2). These results suggest that IL-6 promoter genotypes may be associated with increased risk of plasma cell neoplasms.

Variations of the interleukin-6 promoter are associated with features of the metabolic syndrome in Caucasian Danes

AIMS/HYPOTHESIS

The cytokine interleukin 6 (IL-6) is an essential regulator of the acute phase response associated with insulin-resistant states including type 2 diabetes and obesity. Three polymorphisms at positions -597, -572, and -174 of the IL6 promoter have been reported to influence IL6 transcription. The aim of this study was to investigate whether the IL6 promoter polymorphisms were associated with features of the WHO-defined metabolic syndrome and related quantitative traits in 7,553 Caucasian Danes.

METHODS

Using analysis of PCR-generated primer extension products by mass spectrometry we examined -597 G/A, -572 G/C, and -174 G/C IL6 variants in the population-based Inter99 study cohort of middle-aged people (n=6,164) and in a group of type 2 diabetic patients (n=1,389).

RESULTS

The -174 G/C and -597 G/A polymorphisms were in strong linkage disequilibrium (R(2)=0.95). In the Inter99 cohort the -174 G-allele was associated with insulin resistance (p<0.02) and dyslipidaemia (p<0.007) whereas the C-allele of the -572 polymorphism was associated with increased serum insulin release during an OGTT (p<0.0005). Composite genotype or haplotype analyses of all 3 IL6 promoter variants showed associations with type 2 diabetes (p<0.002), obesity (p<0.02), and the metabolic syndrome (p<0.01).

CONCLUSIONS

The present studies suggest that single-nucleotide polymorphisms and composite genotypes or haplotypes of the IL6 promoter may be associated with several features of the metabolic syndrome in Caucasians.