CYP19 gene expression in subcutaneous adipose tissue is associated with blood pressure in women with polycystic ovary syndrome

Identification of key genes and molecular mechanisms associated with low egg production of broiler breeder hens in ad libitum

Background

Overfeeding reduces laying performance in broiler breeder hens, which is associated with obesity, hepatic steatosis and systemic inflammation. To unravel the underlying mechanisms governing the effect of feeding regimes on energy metabolism and egg production, a transcriptomics approach was carried out for screening differentially expressed genes (DEGs) in ovary, liver and adipose tissues of broiler chickens under ad libitum and restricted feeding.

Results

It showed that 289, 388 and 204 DEGs were identified in the adipose, liver and ovary, respectively. These DEGs were significantly enriched in phagosome pathway, lipid transport, activity and nutrient reservoir activity in ovary; steroid hormone biosynthesis and metabolism of xenobiotics by cytochrome P450 pathways in adipose tissue; and the metabolic pathways, peroxisome proliferator-activated receptor (PPAR) and Jak-STAT signaling pathway in liver. Estrogen receptor 1, identified as one of important hubs by constructing PPI network, was up-regulated in ad libitum group, which would make more apolipoproteins be transferred to ovary.

Conclusions

High expression of VTGs, APOB, CYBB and CTSS in ovary would induce excess lipid deposit, oxidative stress and potential damage to ovulation. Our results contribute to understanding effects of feeding regimes on metabolic regulation during egg production of broiler breeder hens and also provide new evidence of metabolic regulation from integrated multi-tissue processes.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5801-3) contains supplementary material, which is available to authorized users.

Pathophysiological mechanisms of gonadotropins- and steroid hormones-related genes in etiology of polycystic ovary syndrome

OBJECTIVES

Polycystic ovary syndrome (PCOS) is an endocrinopathy in women, which, unlike its impact on fertility and health of women, there is no clear understanding about the causal mechanisms of this pathogenesis. The aim of this review paper is to investigate the pathophysiological pathways affecting the PCOS etiology, based on functions of gonadotropins- and steroid hormones-related genes.

MATERIALS AND METHODS

Due to different hormonal and metabolic signs of this complex disorder, different hypotheses are mentioned about etiology of this syndrome. Because of the heterogeneity of the reasons given for this syndrome and the spread of the effective genes in its pathophysiology, most of genes affected by sex-related hormonal imbalances are examined for discriminative diagnosis. For this purpose, published articles and reviews dealing with genetic evaluation of PCOS in women in peer-reviewed journals in PubMed and Google Scholar databases were included in this review.

RESULTS

In previous studies, it has been well demonstrated that PCOS in some individuals have a genetic origin. Pathophysiological functions of genes are primarily responsible for the synthesis of proteins that have role in PCOS before hyperandrogenism including GnRHR, FSHβ, FSHR, LHCGR, CYP19A1, HSD17B, AR and SHBG, and their effects in PCOS of human have been confirmed.

CONCLUSION

Hormonal imbalances are the first reason mentioned in PCOS etiology, and usually characterized with menstrual irregularities in PCOS women. Hyperandrogenism and gonadotropin secretion disorders are shown in PCOS condition, which are related to steroidogenesis pathways and hypothalamic-pituitary-ovarian axis disturbances, respectively.

Identification of a CYP19 Gene Single-Nucleotide Polymorphism Associated with a Reduced Risk of Coronary Heart Disease

OBJECTIVE

An imbalance in sex hormone ratios has been identified in coronary heart disease (CHD), and as a key enzyme in the conversion of androgen to estrogen, aromatase plays an important role in the balance of sex hormone levels. However, there is a paucity of research into the potential roles of aromatase in CHD. In this study, we investigated associations between single-nucleotide polymorphisms (SNPs) in the CYP19 gene, which encodes aromatase, and CHD.

METHODS

We collected 1706 blood samples from CHD patients and control participants and used propensity score matching techniques to match case and control groups with respect to confounding factors. In a final study population, including 596 individuals, we conducted a case-control study to identify associations between three SNPs in CYP19 and CHD using χ(2) or Fisher exact tests, and binary logistic regression analysis. Differences in lipid levels and parameters of echocardiography among individuals with different genotypes were assessed by one-way analysis of variance.

RESULTS

The distributions of rs2289105 alleles in the CYP19 gene differed significantly between the CHD and control groups (p = 0.014), and the heterozygote CT genotype was associated with a significantly lower risk of CHD compared to the homozygous wild-type CC genotype (p = 0.0063 and odds ratio = 0.575). However, blood lipid levels and echocardiographic parameters among individuals with different genotypes did not differ between the CHD and control groups.

CONCLUSIONS

The CT genotype of the rs2289105 polymorphism in the CYP19 gene is associated with a decreased risk of CHD and may be a genetic marker of protection from CHD.

Polycystic ovary syndrome: reviewing diagnosis and management of metabolic disturbances

Polycystic ovary syndrome (PCOS) is a common condition in women at reproductive age associated with reproductive and metabolic dysfunction. Proposed diagnosed criteria for PCOS include two out of three features: androgen excess, menstrual irregularity, and polycystic ovary appearance on ultrasound (PCO), after other causes of hyperandrogenism and dysovulation are excluded. Based on these diagnostic criteria, the most common phenotypes are the "classic PCOS"--hyperandrogenism and oligomenorrhea, with or without PCO; the "ovulatory phenotype"--hyperandrogenism and PCO in ovulatory women; and the "non-hyperandrogenic phenotype", in which there is oligomenorrhea and PCO, without overt hyperandrogenism. The presence of obesity may exacerbate the metabolic and reproductive disorders associated with the syndrome. In addition, PCOS women present higher risk for type 2 diabetes and higher prevalence of cardiovascular risk factors that seems to be associated with the classic phenotype. The main interventions to minimize cardiovascular and metabolic risks in PCOS are lifestyle changes, pharmacological therapy, and bariatric surgery. Treatment with metformin has been shown to improve insulin sensitivity, lowering blood glucose and androgen levels. These effects are more potent when combined with lifestyle interventions. In conclusion, besides reproductive abnormalities, PCOS has been associated to metabolic comorbidities, most of them linked to obesity. Confounders, such as the lack of standard diagnostic criteria, heterogeneity of the clinical presentation, and presence of obesity, make management of PCOS difficult. Therefore, the approach to metabolic abnormalities should be tailored to the risks and treatment goals of each individual woman.

Adipose tissue dysfunction, adipokines, and low-grade chronic inflammation in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a complex condition that affects women of reproductive age, is characterized by ovulatory dysfunction and androgen excess. Women with PCOS present higher prevalence of obesity, central adiposity, and dyslipidemia, and face increased risk of type 2 diabetes. PCOS is closely linked to functional derangements in adipose tissue. Adipocytes seem to be prone to hypertrophy when exposed to androgen excess, as experienced by women with PCOS, and both adipose tissue hypertrophy and hyperandrogenism are related to insulin resistance. Hypertrophic adipocytes are more susceptible to inflammation, apoptosis, fibrosis, and release of free fatty acids. Disturbed secretion of adipokines may also impact the pathophysiology of PCOS through their influence on metabolism and on sex steroid secretion. Chronic low-grade inflammation in PCOS is also related to hyperandrogenism and to the hypertrophy of adipocytes, causing compression phenomena in the stromal vessels, leading to adipose tissue hypoperfusion and altered secretion of cytokines. Lifestyle changes are the first-line intervention for reducing metabolic risks in PCOS and the addition of an insulin-sensitizing drug might be required. Nevertheless, there is not sufficient evidence in favor of any specific pharmacologic therapies to directly oppose inflammation. Further studies are warranted to identify an adipokine that could serve as an indirect marker of adipocyte production in PCOS, representing a reliable sign of metabolic alteration in this syndrome.

Haplotype TGTG from SNP 45T/G and 276G/T of the adiponectin gene contributes to risk of polycystic ovary syndrome

BACKGROUND

Haplotypes of adiponectin gene single nucleotide polymorphisms (SNP) might be related to metabolic disorders.

AIM

To assess whether the prevalence of SNP 45T/G and 276G/T of the adiponectin gene and their haplotypes differ between polycystic ovary syndrome (PCOS) and non-hirsute cycling controls and to investigate the relationship between these haplotypes and risk factors for cardiovascular disease.

SUBJECTS AND METHODS

In this case-control study, 80 women with PCOS and 1500 non-hirsute controls with regular cycles underwent clinical and laboratory measurements. Genotype distribution was analyzed by conventional PCR-restriction fragment length polymorphism.

RESULTS

Compared to controls, PCOS women had greater body mass index (BMI) (31.0±7.9 kg/m² vs 23.4±4.6 kg/m²; p<0.001), waist circumference (92.2±18.8 cm vs 74.5±10.2 cm; p<0.001), and systolic and diastolic blood pressure (124.6±19.9 vs 111.5±13.0 mmHg and 79.2±12.5 vs 71.8±10.6 mmHg; p<0.025), as well as a worse lipid profile (p<0.007), even after adjustment for age and BMI. Genotype distribution was similar in PCOS and controls (45T/G: p=0.399; 276G/T: p=0.135). Six haplotypes were inferred and their frequencies differed significantly between the groups (p=0.001). The TGTG haplotype was more frequent in PCOS than controls (41.3 vs 18.9%). In PCOS, the GG genotype for SNP 276 (p=0.031) and the TGTG haplotype (p=0.023) were associated with higher systolic blood pressure vs other genotypes and haplotypes. Body composition, glucose, insulin, and lipid profile were similar across genotypes and haplotypes in both groups.

CONCLUSIONS

Haplotype TGTG from adiponectin gene variants 45T/G and 276G/T is related to susceptibility to PCOS, and might be associated with increased blood pressure in PCOS.

Cardiovascular Risk in Women With PCOS

Polycystic ovary syndrome (PCOS), or Stein-Leventhal syndrome, is a common endocrine disorder defined by two of the three following features: i) oligoovulation or anovulation, ii) clinical and/or biochemical signs of hyperandrogenism, or iii) polycystic ovaries, once the related endocrinological and gynaecological disorders have been excluded. PCOS does not exclusively involve the reproductive apparatus , it has a complex number of systemic relevancy symptoms. It leads to Metabolic Syndrome, with severe consequences on the cardiovascular apparatus. Many clinical studies have underlined the connection between PCOS and the cardiovascular risk profile of such female patients, due to a lipid/glucose altered metabolism, hypertension, systemic inflammatory condition (assessable by markers such as VES, TNF-alfa, citokines and C-reactive protein (hsPCR) levels), and vascular injuries. Considering the early onset of the disease, PCOS could be considered as a real cardiovascular risk factor which affects the quality of life seriously. The current review aimed to point out the main connections between PCOS and cardiovascular risk factors according to the latest findings coming from literature data analysis, and try to depict the great influences that such a common disease can have on the patients' health integrity.