33 research outputs found
Combined transcriptome and metabolome analyses of metformin effects reveal novel links between metabolic networks in steroidogenic systems.
Metformin is an antidiabetic drug, which inhibits mitochondrial respiratory-chain-complex I and thereby seems to affect the cellular metabolism in many ways. It is also used for the treatment of the polycystic ovary syndrome (PCOS), the most common endocrine disorder in women. In addition, metformin possesses antineoplastic properties. Although metformin promotes insulin-sensitivity and ameliorates reproductive abnormalities in PCOS, its exact mechanisms of action remain elusive. Therefore, we studied the transcriptome and the metabolome of metformin in human adrenal H295R cells. Microarray analysis revealed changes in 693 genes after metformin treatment. Using high resolution magic angle spinning nuclear magnetic resonance spectroscopy (HR-MAS-NMR), we determined 38 intracellular metabolites. With bioinformatic tools we created an integrated pathway analysis to understand different intracellular processes targeted by metformin. Combined metabolomics and transcriptomics data analysis showed that metformin affects a broad range of cellular processes centered on the mitochondrium. Data confirmed several known effects of metformin on glucose and androgen metabolism, which had been identified in clinical and basic studies previously. But more importantly, novel links between the energy metabolism, sex steroid biosynthesis, the cell cycle and the immune system were identified. These omics studies shed light on a complex interplay between metabolic pathways in steroidogenic systems
Urinary steroid profiling in women hints at a diagnostic signature of the polycystic ovary syndrome: A pilot study considering neglected steroid metabolites.
Although the polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women with vast metabolic consequences, its etiology remains unknown and its diagnosis is still made by exclusion. This study aimed at characterizing a large number of urinary steroid hormone metabolites and enzyme activities in women with and without PCOS in order to test their value for diagnosing PCOS.
Comparative steroid profiling of 24h urine collections using an established in-house gas-chromatography mass spectrometry method. Data were collected mostly prospectively. Patients were recruited in university hospitals in Switzerland. Participants were 41 women diagnosed with PCOS according to the current criteria of the Androgen Excess and PCOS Society Task Force and 66 healthy controls. Steroid profiles of women with PCOS were compared to healthy controls for absolute metabolite excretion and for substrate to product conversion ratios. The AUC for over 1.5 million combinations of metabolites was calculated in order to maximize the diagnostic accuracy in patients with PCOS. Sensitivity, specificity, PPV, and NPV were indicated for the best combinations containing 2, 3 or 4 steroid metabolites.
The best single discriminating steroid was androstanediol. The best combination to diagnose PCOS contained four of the forty measured metabolites, namely androstanediol, estriol, cortisol and 20βDHcortisone with AUC 0.961 (95% CI 0.926 to 0.995), sensitivity 90.2% (95% CI 76.9 to 97.3), specificity 90.8% (95% CI 81.0 to 96.5), PPV 86.0% (95% CI 72.1 to 94.7), and NPV 93.7% (95% CI 84.5 to 98.2).
PCOS shows a specific 24h urinary steroid profile, if neglected metabolites are included in the analysis and non-conventional data analysis applied. PCOS does not share a profile with hyperandrogenic forms of congenital adrenal hyperplasias due to single steroid enzyme deficiencies. Thus PCOS diagnosis by exclusion may no longer be warranted. Whether these findings also apply to spot urine and serum, remains to be tested as a next step towards routine clinical applicability
Molecular allergen profiling in horses by microarray reveals Fag e 2 from buckwheat as a frequent sensitizer.
BACKGROUND
Companion animals are also affected by IgE-mediated allergies, but the eliciting molecules are largely unknown. We aimed at refining an allergen microarray to explore sensitization in horses and compare it to the human IgE reactivity profiles.
METHODS
Custom-designed allergen microarray was produced on the basis of the ImmunoCAP ISAC technology containing 131 allergens. Sera from 51 horses derived from Europe or Japan were tested for specific IgE reactivity. The included horse patients were diagnosed for eczema due to insect bite hypersensitivity, chronic coughing, recurrent airway obstruction and urticaria or were clinically asymptomatic.
RESULTS
Horses showed individual IgE-binding patterns irrespective of their health status, indicating sensitization. In contrast to European and Japanese human sensitization patterns, frequently recognized allergens were Aln g 1 from alder and Cyn d 1 from Bermuda grass, likely due to specific respiratory exposure around paddocks and near the ground. The most prevalent allergen for 72.5% of the tested horses (37/51) was the 2S-albumin Fag e 2 from buckwheat, which recently gained importance not only in human but also in horse diet.
CONCLUSION
In line with the One Health concept, covering human health, animal health and environmental health, allergen microarrays provide novel information on the allergen sensitization patterns of the companion animals around us, which may form a basis for allergen-specific preventive and therapeutic concepts
Erratum to: Methods for evaluating medical tests and biomarkers
[This corrects the article DOI: 10.1186/s41512-016-0001-y.]
Evidence synthesis to inform model-based cost-effectiveness evaluations of diagnostic tests: a methodological systematic review of health technology assessments
Background: Evaluations of diagnostic tests are challenging because of the indirect nature of their impact on patient outcomes. Model-based health economic evaluations of tests allow different types of evidence from various sources to be incorporated and enable cost-effectiveness estimates to be made beyond the duration of available study data. To parameterize a health-economic model fully, all the ways a test impacts on patient health must be quantified, including but not limited to diagnostic test accuracy. Methods: We assessed all UK NIHR HTA reports published May 2009-July 2015. Reports were included if they evaluated a diagnostic test, included a model-based health economic evaluation and included a systematic review and meta-analysis of test accuracy. From each eligible report we extracted information on the following topics: 1) what evidence aside from test accuracy was searched for and synthesised, 2) which methods were used to synthesise test accuracy evidence and how did the results inform the economic model, 3) how/whether threshold effects were explored, 4) how the potential dependency between multiple tests in a pathway was accounted for, and 5) for evaluations of tests targeted at the primary care setting, how evidence from differing healthcare settings was incorporated. Results: The bivariate or HSROC model was implemented in 20/22 reports that met all inclusion criteria. Test accuracy data for health economic modelling was obtained from meta-analyses completely in four reports, partially in fourteen reports and not at all in four reports. Only 2/7 reports that used a quantitative test gave clear threshold recommendations. All 22 reports explored the effect of uncertainty in accuracy parameters but most of those that used multiple tests did not allow for dependence between test results. 7/22 tests were potentially suitable for primary care but the majority found limited evidence on test accuracy in primary care settings. Conclusions: The uptake of appropriate meta-analysis methods for synthesising evidence on diagnostic test accuracy in UK NIHR HTAs has improved in recent years. Future research should focus on other evidence requirements for cost-effectiveness assessment, threshold effects for quantitative tests and the impact of multiple diagnostic tests
Erratum to: Methods for evaluating medical tests and biomarkers
[This corrects the article DOI: 10.1186/s41512-016-0001-y.]
Regulation of androgen biosynthesis - A short review and preliminary results from the hyperandrogenic starvation NCI-H295R cell model
Regulation of androgen production is poorly understood. Adrenarche is the physiologic event in mid-childhood when the adrenal zona reticularis starts to produce androgens through specific expression of genes for enzymes and cofactors necessary for androgen synthesis. Similarly, expression and activities of same genes and products are deregulated in hyperandrogenic disorders such as the polycystic ovary syndrome (PCOS). Numerous studies revealed involvement of several signaling pathways stimulated through G-protein coupled receptors or growth factors transmitting their effects through cAMP- or non-cAMP-dependent signaling. Overall a complex network regulates androgen synthesis targeting involved genes and proteins at the transcriptional and post-translational levels. Newest players in the field are the DENND1A gene identified in PCOS patients and the MAPK14 which is the kinase phosphorylating CYP17 for enhanced lyase activity. Next generation sequencing studies of PCOS patients and transcriptome analysis of androgen producing tissues or cell models provide newer tools to identify modulators of androgen synthesis
Resveratrol inhibits androgen production of human adrenocortical H295R cells by lowering CYP17 and CYP21 expression and activities
<div><p>Resveratrol, a natural compound found in grapes, became very popular for its suggested protective effects against aging. It was reported to have similar positive effects on the human metabolism as caloric restriction. Recently, positive effects of resveratrol on steroid biosynthesis in cell systems and in humans suffering from polycystic ovary syndrome have also been reported, but the exact mechanism of this action remains unknown. Sirtuins seem targeted by resveratrol to mediate its action on energy homeostasis. In this study, we investigated the mechanisms of action of resveratrol on steroidogenesis in human adrenal H295R cells. Resveratrol was found to inhibit protein expression and enzyme activities of CYP17 and CYP21. It did not alter CYP17 and CYP21 mRNA expression, nor protein degradation. Only SIRT3 mRNA expression was found to be altered by resveratrol, but SIRT1, 3 and 5 overexpression did not result in a change in the steroid profile of H295R cells, indicating that resveratrol may not engage sirtuins to modulate steroid production. Previous studies showed that starvation leads to a hyperandrogenic steroid profile in H295R cells through inhibition of PKB/Akt signaling, and that resveratrol inhibits steroidogenesis of rat ovarian theca cells via the PKB/Akt pathway. Therefore, the effect of resveratrol on PKB/Akt signaling was tested in H295R cells and was found to be decreased under starvation growth conditions, but not under normal growth conditions. Overall, these properties of action together with recent clinical findings make resveratrol a candidate for the treatment of hyperandrogenic disorders such as PCOS.</p></div
Phenotypic variability in familial combined pituitary hormone deficiency caused by a PROP1 gene mutation resulting in the substitution of Arg-->Cys at codon 120 (R120C).
As pituitary function depends on the integrity of the hypothalamic-pituitary axis, any defect in the development and organogenesis of this gland may account for a form of combined pituitary hormone deficiency (CPHD). A mutation in a novel, tissue-specific, paired-like homeodomain transcription factor, termed Prophet of Pit-1 (PROP1), has been identified as causing the Ames dwarf (df) mouse phenotype, and thereafter, different PROP1 gene alterations have been found in humans with CPHD. We report on the follow-up of two consanguineous families (n = 12), with five subjects affected with CPHD (three males and two females) caused by the same nucleotide C to T transition, resulting in the substitution of Arg-->Cys in PROP1 at codon 120. Importantly, there is a variability of phenotype, even among patients with the same mutation. The age at diagnosis was dependent on the severity of symptoms, ranging from 9 months to 8 yr. Although in one patient TSH deficiency was the first symptom of the disorder, all patients became symptomatic by exhibiting severe growth retardation and failure to thrive, which was mainly caused by GH deficiency (n = 4). The secretion of the pituitary-derived hormones (GH, PRL, TSH, LH, and FSH) declined gradually with age, following a different pattern in each individual; therefore, the deficiencies developed over a variable period of time. All of the subjects entered puberty spontaneously, and the two females also experienced menarche and periods before a replacement therapy was necessary