Impaired repression at a vasopressin promoter polymorphism in a rat model of trait anxiety and depression

Two inbred rat lines have been developed that show either high (HAB) or low (LAB) anxiety-related behavior. The behavioral phenotype correlates with arginine vasopressin (AVP) expression at the level of the hypothalamic paraventricular nucleus (PVN), but not supraoptic nucleus, with HAB animals overexpressing the neuropeptide in both magnocellular and parvocellular subdivisions of the PVN. This study aimed to investigate the molecular cause of the AVP overexpression in the PVN of the HAB animals. Sequencing of the AVP locus resulted in the detection of a number of single nucleotide polymorphisms (SNPs) in the promoter differing between the HAB and LAB animals. Two of the SNPs were embedded in cis-regulatory elements. Genotyping further revealed that the HAB-specific allele of the AVP gene promoter occurs in 1.5% of outbred Wistar rats. An assay was developed to address the question of differential allele-specific transcription rates between the LAB and HAB alleles using cross-mated HAB/LAB F1 animals. Results from the experiment revealed the HAB AVP promoter to be more transcriptionally active in vivo. EMSA assays confirmed that one specific SNP [A(-1276)G] conferred reduced binding of the transcriptional repressor CArG binding factor A (CBF-A) in the HAB allele. Reporter gene assays supported the view that the A(-1276)G transition in the CArG element impairs CBF-A repression in the HAB allele, which in turn relates to a weakened repression of the intact HAB AVP promoter by CBF-A. Furthermore, CBF-A is highly co-expressed in AVP-containing neurons of the PVN supporting an important role for regulation of AVP gene expression in vivo. Taken together, these results demonstrate a role for an AVP gene polymorphism and CBF-A in elevated AVP expression in the PVN of HAB rats likely to contribute to their behavioral and neuroendocrine phenotype. Phenotypic variation among organisms is central to evolutionary adaptations underlying natural and artificial selection, and also determines individual susceptibility to common diseases including cardiovascular, metabolic and age related and psychiatric diseases. Most phenotypic diversity in natural populations is characterised by differences in degree rather than in kind. In accordance with this view, HAB rats lacked changes in the coding part of the vasopressin gene, but instead were homozygous for the polymorphic promoter region. Therefore, the HAB specific AVP promoter represents a natural model for AVP overexpression and highlights, in turn, cognate molecular pathways which potentially fuel the resulting pathologies. Specifically, our finding that the SNP in position 1276 of the AVP gene promoter underlies AVP overexpression in the PVN of HAB rats, makes this SNP a potential target for further studies aimed at improving therapeutic tools. Finally, further studies are necessary to understand to which degree and in concert with which vulnerability loci vasopressin overexpression underlies the complex neuroendocrine and behavioural stigmata in the HAB line. Certainly, such studies will yield important insights into gene-gene interactions between susceptibility genes and shed light on additional pathways suitable for therapeutic interventions. In conclusion, this present work exemplifies that selective inbreeding for behavioural traits and combined phenotypic and molecular analysis of candidate genes is an important step and tool to address these issues

Neuroinflammation in mild cognitive impairment and Alzheimer's disease: A meta-analysis.

BACKGROUND:Increasingly, evidence from brain imaging supports the role of neuroinflammation in dementia progression. Yet, it is not clear if there are patterns of spatial and temporal susceptibility to neuroinflammatory processes in the brain that may correspond to dementia staging or symptom expression. METHODS:We searched literature databases for case-control studies examining levels of translocator protein (TSPO) levels using positron emission tomography, representing neuroinflammation, in regional analyses between healthy controls and mild cognitive impairment (MCI) or Alzheimer's disease (AD) subjects. Standardised mean differences (SMDs) were calculated and results meta-analysed using random-effects models. Quality assessments, sensitivity analysis, subgroup analysis and meta-regressions were also performed. RESULTS:Twenty-eight studies comprising 755 (HC = 318, MCI = 168, AD = 269) participants and 37 brain regions were included. Compared to HCs, AD participants had increased TSPO levels throughout the brain (SMD range: 0.43 - 1.76), especially within fronto-temporal regions. MCI subjects also had increased TSPO levels, mainly within the neocortex, with more modest effects (SMD range: 0.46 - 0.90). Meta-regression analysis identified an inverse association between TSPO levels in the parietal region and Mini-Mental State Examination scores, a proxy for disease severity, in AD subjects (estimate: -0.11, 95% confidence interval: -0.21 to -0.02; P = 0.024). CONCLUSIONS:Our findings support the association of increased neuroinflammation during the progression of MCI and AD, relative to HCs

Structure-activity relationships of the Human Immunodeficiency Virus type 1 maturation inhibitor PF-46396

This work was funded by the University of St Andrews and Society for Applied Microbiology New Lecturer Research Grant awarded to CSA, Wellcome Trust grant (093228) awarded to TKS.HIV-1 maturation inhibitors are a novel class of antiretroviral compounds, which consist of two structurally distinct chemical classes; betulinic acid derivatives and the pyridone-based compound PF-46396. It is currently believed that both classes act by a similar mode of action to generate aberrant non-infectious particles via inhibition of CA-SP1 cleavage during Gag proteolytic processing. In this study we utilized a series of novel analogues, with decreasing similarity to PF-46396, to determine the chemical groups within PF-46396 that contribute to antiviral activity, Gag binding and the relationship between these essential properties. A spectrum of antiviral activity (active, intermediate, inactive) was observed across the analogue series with respect to CA-SP1 cleavage and HIV-1 (NL4-3) replication kinetics in Jurkat T cells. We demonstrate that selected inactive analogues are incorporated into WT immature particles and that one inactive analogue is capable of interfering with PF-46396 inhibition of CA-SP1 cleavage. Mutations that confer PF-46396 resistance can impose a defective phenotype on HIV-1 that can be rescued in a compound-dependent manner. Some inactive analogues retained the capacity to rescue PF-46396-dependent mutants (SP1-A3V, SP1-A3T, CA-P157S), implying that they can also interact with mutant Gag. The structure-activity relationships observed in this study demonstrate that (i) the tert-butyl group is essential for antiviral activity, but not an absolute requirement for Gag binding, (ii) the trifluromethyl group is optimal but not essential for antiviral activity and (iii) the 2-aminoindan group is important for antiviral activity and Gag binding but not essential as its replacement is tolerated.Publisher PDFPeer reviewe

Centile reference chart for resting metabolic rate through the life course

OBJECTIVE: Reference centile charts are widely used for the assessment of growth and have progressed from describing height and weight to include body composition variables such as fat and lean mass. Here, we present centile charts for an index of resting energy expenditure (REE) or metabolic rate, adjusted for lean mass versus age, including both children and adults across the life course. DESIGN, PARTICIPANTS AND INTERVENTION: Measurements of REE by indirect calorimetry and body composition using dual-energy X-ray absorptiometry were made in 411 healthy children and adults (age range 6-64 years) and serially in a patient with resistance to thyroid hormone α (RTHα) between age 15 and 21 years during thyroxine therapy. SETTING: NIHR Cambridge Clinical Research Facility, UK. RESULTS: The centile chart indicates substantial variability, with the REE index ranging between 0.41 and 0.59 units at age 6 years, and 0.28 and 0.40 units at age 25 years (2nd and 98th centile, respectively). The 50th centile of the index ranged from 0.49 units (age 6 years) to 0.34 units (age 25 years). Over 6 years, the REE index of the patient with RTHα varied from 0.35 units (25th centile) to 0.28 units (<2nd centile), depending on changes in lean mass and adherence to treatment. CONCLUSION: We have developed a reference centile chart for an index of resting metabolic rate in childhood and adults, and shown its clinical utility in assessing response to therapy of an endocrine disorder during a patient's transition from childhood to adult

Cityscapes without figures: geophysics, computing and the future of urban studies

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Associations of sperm telomere length with semen parameters, clinical outcomes and lifestyle factors in human normozoospermic samples

Background Many studies have demonstrated that lifestyle factors can affect sperm quality and fertility. Sperm telomere length (STL) has been reported as potential biomarker or sperm quality. However, no studies have investigated how lifestyle factors can affect STL and associated clinical outcomes. Objectives The purpose of this manuscript is to investigate any association between STL with lifestyle factors, semen parameters and clinical outcomes. Materials and methods Sperm telomere length was measured using real‐time PCR in normozoospermic male partners (n = 66) of couples undergoing ART treatment. Each participant also completed a detailed questionnaire about general lifestyle. Linear regression univariate analysis and ANCOVA were performed to respectively determine correlations between STL and study parameters or identify statistically significant differences in STL while controlling for age, BMI and other factors. Results Using a linear regression model, STL is positively correlated with in vitro fertilization success (n = 65, r = 0.37, P = .004) but not with embryo cleavage rates and post‐implantation clinical outcomes including gestational age‐adjusted birth weight. No associations were observed between STL and sperm count, concentration or progressive motility. We further found that STL did not associate age, BMI, health or lifestyle factors. Discussion In somatic cells, the rate of telomere shortening is influenced by a number of lifestyle factors such as smoking, diet and occupation. However, little is known about how lifestyle factors affect STL and subsequently reproductive outcome. Out data suggest that STL might have an important role mechanistically for fertilization rate regardless of sperm parameters and lifestyle factors. Conclusion The results of this study demonstrate that STL is associated with in vitro fertilization rates, but not with semen parameters nor lifestyle factors. Further investigations are warranted to identify the potential variation of STL overtime to clarify its significance as a potential biomarker in ART

The anxiety and ethanol intake controlling GAL5.1 enhancer is epigenetically modulated by, and controls preference for, high-fat diet

Excess maternal fat intake and obesity increase offspring susceptibility to conditions such as chronic anxiety and substance abuse. We hypothesised that environmentally modulated DNA methylation changes (5mC/5hmC) in regulatory regions of the genome that modulate mood and consumptive behaviours could contribute to susceptibility to these conditions. We explored the effects of environmental factors on 5mC/5hmC levels within the GAL5.1 enhancer that controls anxiety-related behaviours and alcohol intake. We first observed that 5mC/5hmC levels within the GAL5.1 enhancer differed significantly in different parts of the brain. Moreover, we noted that early life stress had no significant effect of 5mC/5hmC levels within GAL5.1. In contrast, we identified that allowing access of pregnant mothers to high-fat diet (&gt; 60% calories from fat) had a significant effect on 5mC/5hmC levels within GAL5.1 in hypothalamus and amygdala of resulting male offspring. Cell transfection-based studies using GAL5.1 reporter plasmids showed that 5mC has a significant repressive effect on GAL5.1 activity and its response to known stimuli, such as EGR1 transcription factor expression and PKC agonism. Intriguingly, CRISPR-driven disruption of GAL5.1 from the mouse genome, although having negligible effects on metabolism or general appetite, significantly decreased intake of high-fat diet suggesting that GAL5.1, in addition to being epigenetically modulated by high-fat diet, also actively contributes to the consumption of high-fat diet suggesting its involvement in an environmentally influenced regulatory loop. Furthermore, considering that GAL5.1 also controls alcohol preference and anxiety these studies may provide a first glimpse into an epigenetically controlled mechanism that links maternal high-fat diet with transgenerational susceptibility to alcohol abuse and anxiety

Maternal Immune Activation Induces Adolescent Cognitive Deficits Preceded by Developmental Perturbations in Cortical Reelin Signalling.

Exposure to maternal immune activation (MIA) in utero significantly elevates the risk of developing schizophrenia and other neurodevelopmental disorders. To understand the biological mechanisms underlying the link between MIA and increased risk, preclinical animal models have focussed on specific signalling pathways in the brain that mediate symptoms associated with neurodevelopmental disorders such as cognitive dysfunction. Reelin signalling in multiple brain regions is involved in neuronal migration, synaptic plasticity and long-term potentiation, and has been implicated in cognitive deficits. However, how regulation of Reelin expression is affected by MIA across cortical development and associated cognitive functions remains largely unclear. Using a MIA rat model, here we demonstrate cognitive deficits in adolescent object-location memory in MIA offspring and reductions in Reln expression prenatally and in the adult prefrontal cortex. Further, developmental disturbances in gene/protein expression and DNA methylation of downstream signalling components occurred subsequent to MIA-induced Reelin dysregulation and prior to cognitive deficits. We propose that MIA-induced dysregulation of Reelin signalling contributes to the emergence of prefrontal cortex-mediated cognitive deficits through altered NMDA receptor function, resulting in inefficient long-term potentiation. Our data suggest a developmental window during which attenuation of Reelin signalling may provide a possible therapeutic target