The R453Q and D151A polymorphisms of Hexose-6-Phosphate Dehydrogenase Gene (H6PD) influence the polycystic ovary syndrome (PCOS) and obesity

Global Gene Expression Profiling and Transcription Factor Network Analysis of Cognitive Aging in Monozygotic Twins

Cognitive aging is one of the major problems worldwide, especially as people get older. This study aimed to perform global gene expression profiling of cognitive function to identify associated genes and pathways and a novel transcriptional regulatory network analysis to identify important regulons. We performed single transcript analysis on 400 monozygotic twins using an assumption-free generalized correlation coefficient (GCC), linear mixed-effect model (LME) and kinship model and identified six probes (one significant at the standard FDR < 0.05 while the other results were suggestive with 0.18 ≤ FDR ≤ 0.28). We combined the GCC and linear model results to cover diverse patterns of relationships, and meaningful and novel genes like APOBEC3G, H6PD, SLC45A1, GRIN3B, and PDE4D were detected. Our exploratory study showed the downregulation of all these genes with increasing cognitive function or vice versa except the SLC45A1 gene, which was upregulated with increasing cognitive function. Linear models found only H6PD and SLC45A1, the other genes were captured by GCC. Significant functional pathways (FDR < 3.95e-10) such as focal adhesion, ribosome, cysteine and methionine metabolism, Huntington's disease, eukaryotic translation elongation, nervous system development, influenza infection, metabolism of RNA, and cell cycle were identified. A total of five regulons (FDR< 1.3e-4) were enriched in a transcriptional regulatory analysis in which CTCF and REST were activated and SP3, SRF, and XBP1 were repressed regulons. The genome-wide transcription analysis using both assumption-free GCC and linear models identified important genes and biological pathways implicated in cognitive performance, cognitive aging, and neurological diseases. Also, the regulatory network analysis revealed significant activated and repressed regulons on cognitive function.

DNA methylation differences at birth after conception through ART

STUDY QUESTION

Is there a relation between ART and DNA methylation (DNAm) patterns in cord blood, including any differences between IVF and ICSI?

SUMMARY ANSWER

DNAm at 19 CpGs was associated with conception via ART, with no difference found between IVF and ICSI.

WHAT IS KNOWN ALREADY

Prior studies on either IVF or ICSI show conflicting outcomes, as both widespread effects on DNAm and highly localized associations have been reported. No study on both IVF and ICSI and genome-wide neonatal DNAm has been performed.

STUDY DESIGN, SIZE, DURATION

This was a cross-sectional study comprising 87 infants conceived with IVF or ICSI and 70 conceived following medically unassisted conception. The requirement for inclusion in the study was an understanding of the Swedish language and exclusion was the use of donor gametes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were from the UppstART study, which was recruited from fertility and reproductive health clinics, and the Born into Life cohort, which is recruited from the larger LifeGene study. We measured DNAm from DNA extracted from cord blood collected at birth using a micro-array (450k array). Group differences in DNAm at individual CpG dinucleotides (CpGs) were determined using robust linear models and post-hoc Tukey’s tests.

MAIN RESULTS AND THE ROLE OF CHANCE

We found no association of ART conception with global methylation levels, imprinted loci and meta-stable epialleles. In contrast, we identify 19 CpGs at which DNAm was associated with being conceived via ART (effect estimates: 0.5–4.9%, P_FDR < 0.05), but no difference was found between IVF and ICSI. The associated CpGs map to genes related to brain function/development or genes connected to the plethora of conditions linked to subfertility, but functional annotation did not point to any likely functional consequences.

LIMITATIONS, REASONS FOR CAUTION

We measured DNAm in cord blood and not at later ages or in other tissues. Given the number of tests performed, our study power is limited and the findings need to be replicated in an independent study.

WIDER IMPLICATIONS OF THE FINDINGS

We find that ART is associated with DNAm differences in cord blood when compared to non-ART samples, but these differences are limited in number and effect size and have unknown functional consequences in adult blood. We did not find indications of differences between IVF and ICSI.

STUDY FUNDING/COMPETING INTEREST(S)

E.W.T. was supported by a VENI grant from the Netherlands Organization for Scientific Research (91617128) and JPI-H2020 Joint Programming Initiative a Healthy Diet for a Healthy Life (JPI HDHL) under proposal number 655 (PREcisE Project) through ZonMw (529051023). Financial support was provided from the European Union’s Seventh Framework Program IDEAL (259679), the Swedish Research Council (K2011-69X-21871-01-6, 2011-3060, 2015-02434 and 2018-02640) and the Strategic Research Program in Epidemiology Young Scholar Awards, Karolinska Institute (to A.N.I.) and through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) framework grant no 340-2013-5867, grants provided by the Stockholm County Council (ALF-projects), the Strategic Research Program in Epidemiology at Karolinska Institutet and the Swedish Heart-Lung Foundation and Danderyd University Hospital (Stockholm, Sweden). The funders had no role in study design, data collection, analysis, decision to publish or preparation of the manuscript. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

ScanBious: Survey for Obesity Genes Using PubMed Abstracts and DisGeNET

We used automatic text-mining of PubMed abstracts of papers related to obesity, with the aim of revealing that the information used in abstracts reflects the current understanding and key concepts of this widely explored problem. We compared expert data from DisGeNET to the results of an automated MeSH (Medical Subject Heading) search, which was performed by the ScanBious web tool. The analysis provided an overview of the obesity field, highlighting major trends such as physiological conditions, age, and diet, as well as key well-studied genes, such as adiponectin and its receptor. By intersecting the DisGeNET knowledge with the ScanBious results, we deciphered four clusters of obesity-related genes. An initial set of 100+ thousand abstracts and 622 genes was reduced to 19 genes, distributed among just a few groups: heredity, inflammation, intercellular signaling, and cancer. Rapid profiling of articles could drive personalized medicine: if the disease signs of a particular person were superimposed on a general network, then it would be possible to understand which are non-specific (observed in cohorts and, therefore, most likely have known treatment solutions) and which are less investigated, and probably represent a personalized case.

Lack of adipose-specific hexose-6-phosphate dehydrogenase causes inactivation of adipose glucocorticoids and improves metabolic phenotype in mice

Excessive glucocorticoid (GC) production in adipose tissue promotes the development of visceral obesity and metabolic syndrome (MS). 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is critical for controlling intracellular GC production, and this process is tightly regulated by hexose-6-phosphate dehydrogenase (H6PDH). To better understand the integrated molecular physiological effects of adipose H6PDH, we created a tissue-specific knockout of the H6PDH gene mouse model in adipocytes (adipocyte-specific conditional knockout of H6PDH (H6PDHAcKO) mice). H6PDHAcKO mice exhibited almost complete absence of H6PDH expression and decreased intra-adipose corticosterone production with a reduction in 11β-HSD1 activity in adipose tissue. These mice also had decreased abdominal fat mass, which was paralleled by decreased adipose lipogenic acetyl-CoA carboxylase (ACC) and ATP-citrate lyase (ACL) gene expression and reduction in their transcription factor C/EBPα mRNA levels. Moreover, H6PDHAcKO mice also had reduced fasting blood glucose levels, increased glucose tolerance, and increased insulin sensitivity. In addition, plasma free fatty acid (FFA) levels were decreased with a concomitant decrease in the expression of lipase adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) in adipose tissue. These results indicate that inactivation of adipocyte H6PDH expression is sufficient to cause intra-adipose GC inactivation that leads to a favorable pattern of metabolic phenotypes. These data suggest that H6PDHAcKO mice may provide a good model for studying the potential contributions of fat-specific H6PDH inhibition to improve the metabolic phenotype in vivo. Our study suggests that suppression or inactivation of H6PDH expression in adipocytes could be an effective intervention for treating obesity and diabetes.

Multi-system reproductive metabolic disorder: significance for the pathogenesis and therapy of polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS), a multisystem disease, is a major reason for female infertility around the world. It is no longer considered simply as a disease of ovary. Now researchers growing awareness of the multisystem features of this disease. PCOS has a higher relationship with metabolic disturbance and hypothalamic-pituitary-ovarian axis (HPOA) function disorders. This syndrome results in hyperandrogenemia (HA), hyperinsulinemia/insulin resistance (IR), increased estrone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) ratio imbalance, infertility, cardiovascular diseases, endometrial dysfunction, obesity, and including a litany of other health issues. Furthermore, PCOS has been garnered in recent times. Interventions like metformin, orlistat, hormonal contraceptives, GLP1 agonists, and VitD have been applied to ameliorate or reverse the pathological characterization of PCOS. Moreover, drug-combined therapy of PCOS is superior to single drug administration. This review will focus on the recent progress in pathogenesis and therapy of PCOS.

Uncovering the mechanism whereby dietary nicotinic acid increases the intramuscular fat content in finishing steers by RNA sequencing analysis

In our previous study, we found that a higher dosage of nicotinic acid (NA) in the diet dramatically increases intramuscular fat (IMF) content and improves meat quality in finishing steers. We hypothesised that increased IMF results from the regulation of genes associated with adipogenesis. To address this hypothesis, RNA-seq was used to investigate gene-expression profiles of longissimus muscles from the same 16 cattle that were also used in our previous study and treated with or without dietary NA. Four cDNA libraries were constructed and sequenced. The repeatability and reproducibility of RNA-seq data were confirmed by quantitative reverse-transcription polymerase-chain reaction. In total, 123 differentially expressed genes (DEGs) were identified between longissimus muscles treated and those not treated with dietary NA. Of the 123 DEGs, 117 genes were upregulated by the NA treatment. These DEGs were enriched in 21 pathways, including the extracellular matrix (ECM) –receptor interaction, PPAR signalling pathway, adipocytokine signalling pathway and transforming growth factor-β signalling pathway, all of which are associated with lipid metabolism. Furthermore, candidate genes related to adipocyte differentiation and adipogenesis (PLIN1, PLIN2, ADPN, LEP, LCN2 and SOCS3), lipid metabolism (FABP4, RBP4, GAL, ANXA1, ANXA2 and PTX3) and fatty acid synthesis and esterification (ELOVL6, ACSM1, SOT1 and PTGIS) were upregulated in the NA group. Three genes involved in glucose metabolism (PGAM1, UGDH and GLUT3) were also transcriptionally upregulated. However, MYH4 that encodes glycolytic Type IIb muscle fibres was downregulated by dietary NA. These gene expression results indicated a confirmation of our hypothesis that dietary NA increases the IMF content of longissimus muscle through upregulating the expression of the genes related to adipocyte differentiation, adipogenesis and lipid and glucose metabolism.

Insulin resistance in obesity and polycystic ovary syndrome: systematic review and meta-analysis of observational studies

We aimed at investigating whether insulin resistance (IR)/sensitivity are impaired in obese/non-obese polycystic ovary syndrome (PCOS) and obese/non-obese healthy controls. A comprehensive literature search was performed for observational, English language studies. Meta-analysis was performed with the random effects model according to the heterogeneity. Eligible studies, involving 3037 women in four groups of: 1-obese, PCOS; 2-non-obese, PCOS, 3-obese, non-PCOS and 4-Non-obese, non-PCOS were included. Based on the insulin resistance index (HOMA-IR) analysis, the pooled mean (95% Conf. Interval) of HOMA IR in groups 1-4 were 4.38 (3.84, 4.92), 2.68 (2.16, 3.20), 2.44 (2.06, 2.82) and 1.34 (1.06, 1.63), respectively. Meta-analysis showed that group 1 (obese, PCOS patients) statistically have the highest IR and group 4 (non-obese, non-PCOS women) have the highest insulin sensitivity. Group 2 (non-obese, PCOS patients) and group 3 (obese, non-PCOS women) were between this range and they had lower IR than group 1 (obese, PCOS) and lower insulin sensitivity than group 4 (non-obese, non-PCOS). So, there were statistical differences between all groups except between groups 2 and 3. Insulin sensitivity indexes (quickie and ISI), also confirm the IR index (HOMA-IR) results. Based on different IR/sensitivity indexes, we found no evidence of any different effects of BMI ≥ 30 kg/m(2) on IR/sensitivity. In conclusion, PCOS status intensifies the adverse effects of obesity on IR, it has to be appropriately addressed in primary and secondary preventive cares and treatments provided for these women.

Association Analysis between the Polymorphisms of HSD11B1 and H6PD and Risk of Polycystic Ovary Syndrome in Chinese Population

Objectives

To evaluate whether single nucleotide polymorphisms of HSD11B1 (rs846908) and H6PD (rs6688832 and rs17368528) are associated with polycystic ovary syndrome (PCOS) in Chinese population.

Materials and Methods

A case-control study was implemented to investigate the association between HSD11B1 and H6PD polymorphisms and PCOS. Patients with PCOS (n = 335) and controls (n = 354) were recruited in this study. Genetic variants of HSD11B1 (rs846908) and H6PD (rs6688832 and rs17368528) were analyzed by TaqMan method.

Results

We found a significantly 0.79-fold lower risk of G allele of rs6688832 in control group compared with the patients with PCOS (adjusted OR, 0.79; 95%CI = 0.63–0.99; P = 0.040). Additionally, significant difference in the levels of follicle stimulating hormone (FSH) was observed between AA and AG genotype in rs6688832. The rs6688832 AG genotype was associated with lower level of FSH (P = 0.039) and higher risk of hyperandrogenism (P = 0.016) in patients with PCOS. When all subjects were divided into different subgroups according to age and body mass index (BMI), we found that the frequency of G allele of rs6688832 was significantly higher in controls than that in PCOS patients in the subgroup of BMI > 23 (adjusted OR, 0.70; 95% CI = 0.50–0.98; P = 0.037).

Conclusions

Our findings showed a statistical association between H6PD rs6688832 and PCOS risk in Chinese population. The G allele of rs6688832 in H6PD might exert potential genetic protective role against the development of PCOS, especially in overweight women. PCOS patients with AG genotype of rs6688832 might confer risk to the phenotype of hyperandrogenemia of PCOS.

11β-Hydroxysteroid dehydrogenase 1: translational and therapeutic aspects

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) interconverts the inactive glucocorticoid cortisone and its active form cortisol. It is widely expressed and, although bidirectional, in vivo it functions predominantly as an oxoreductase, generating active glucocorticoid. This allows glucocorticoid receptor activation to be regulated at a prereceptor level in a tissue-specific manner. In this review, we will discuss the enzymology and molecular biology of 11β-HSD1 and the molecular basis of cortisone reductase deficiencies. We will also address how altered 11β-HSD1 activity has been implicated in a number of disease states, and we will explore its role in the physiology and pathologies of different tissues. Finally, we will address the current status of selective 11β-HSD1 inhibitors that are in development and being tested in phase II trials for patients with the metabolic syndrome. Although the data are preliminary, therapeutic inhibition of 11β-HSD1 is also an exciting prospect for the treatment of a variety of other disorders such as osteoporosis, glaucoma, intracranial hypertension, and cognitive decline.