548 research outputs found
Understanding the Dynamics of Gene Regulatory Systems : Characterisation and Clinical Relevance of cis-Regulatory Polymorphisms
Peer reviewedPublisher PD
Oxidative stress in endothelial cells of patients with coronary artery disease
There is increasing evidence to support a role for vascular oxidative stress in the development of endothelial dysfunction and coronary artery disease (CAD). The prevalence of CAD in patients with type 2 diabetes (T2D) is more than ten times greater than in the general population and CAD patients with T2D display poorer clinical outcomes than those without. Previous investigations carried out within this laboratory have demonstrated endothelial dysfunction and elevated superoxide (O2-) production throughout the vessel wall in saphenous veins from patients with advanced CAD. However, the molecular basis for these findings was not investigated, nor was the effect of T2D. Consequently, the aim of this study was to investigate a number of molecular determinants of oxidative stress in primary human saphenous vein endothelial cells (HSVECs) from CAD patients both with and without T2D, the hypothesis being that oxidative stress leads to endothelial dysfunction in CAD and is exacerbated in those patients with T2D.
Initial experiments confirmed the findings of previous studies, revealing significantly elevated O2- levels and impaired endothelium-dependent relaxation in portions of saphenous vein from patients with CAD related to those from healthy control subjects. In addition, results demonstrated more severe endothelial dysfunction in vessels from CAD patients with T2D relative to those CAD patients without this additional cardiovascular risk factor.
Attempts to characterise cellular sources of elevated O2- production in the endothelium of patients with CAD revealed that while HSVEC endothelial nitric oxide synthase (eNOS) is not a major source of O2- generation in CAD, nicotinamide adenine (phosphate) dinucleotide (NAD(P)H) oxidase contributes to excess O2- production in the endothelium of patients with this cardiovascular disease.
Further cellular investigation revealed a significant increase in expression of mitochondrial superoxide dismutase (SOD2) in HSVECs from CAD patients, in particular those with T2D. Mitochondrially-derived reactive oxygen species (mtROS) are reported to contribute to oxidative stress and endothelial dysfunction in CAD and T2D and, as such, this increase in SOD2 expression is likely to represent an adaptive response to elevated mitochondrial O2- production. In addition, analysis of gene expression microarray data revealed differential expression of a number of genes potentially linked to mitochondrial function, serving to support a key role for mitochondrial dysfunction in the pathogenesis of CAD and T2D.
Additional molecular studies focused on AMP-activated protein kinase (AMPK). Proposed as a candidate target for therapeutic intervention in endothelial dysfunction, AMPK stimulates eNOS, leading to nitric oxide (NO) production in cultured endothelial cells. Furthermore, it has recently been reported that endothelial AMPK is activated in a mtROS-mediated manner. With SOD2 expression data indicating an increase in mtROS production in the endothelium of patients with CAD, AMPK activity was investigated and compared in HSVECs isolated from these patients and control subjects. AMPK activity was significantly greater in cells from patients with CAD, despite no change in activity of upstream kinases, LKB1 and Ca2+/calmodulin-dependent kinase kinase (CaMKK). On stratifying CAD patients according to the presence of T2D, AMPK activity was found to be significantly increased in the endothelium of those patients with CAD and T2D as compared to those with CAD alone. Given the potentially elevated levels of mtROS production in the endothelium of patients with CAD, it seemed likely that endothelial AMPK activation in CAD patients was occurring in an mtROS-mediated manner and that this activation was enhanced in those CAD patients with T2D who display more severe endothelial dysfunction and increased SOD2 expression, consistent with increased mtROS production. In order to test this hypothesis, HSVECs isolated from vessels of CAD patients were treated with the mitochondria-targeted antioxidant, MitoQ10. Results demonstrated a significant decrease in AMPK activation in cells from those CAD patients with T2D on treatment with MitoQ10. The same effect was not seen in cells from CAD patients without T2D. These findings indicate that AMPK is activated in a mtROS-mediated manner in endothelial cells isolated from CAD patients with T2D and suggest a role for the kinase in defence against oxidative stress and endothelial dysfunction in these individuals.
In summary, a wide range of molecular techniques have been employed to investigate cellular mechanisms underlying the oxidative stress and endothelial dysfunction associated with CAD. Results suggest mitochondria contribute to the increased O2- production and endothelial dysfunction observed in vessels from CAD patients. In addition, findings indicate a novel, mtROS-mediated activation of AMPK in the endothelium of patients with CAD and T2D. Therefore, mitochondria-targeted antioxidants, used in combination with pharmacological activators of AMPK, may have enhanced potential in prevention and treatment of coronary artery disease in patients with type 2 diabetes
Evidence for regulatory diversity and auto-regulation at the TAC1 locus in sensory neurones
Peer reviewedPublisher PD
Development of a core outcome set for behavioural weight management programmes for adults with overweight and obesity:protocol for obtaining expert consensus using Delphi methodology
Introduction: Weight management interventions in research studies and in clinical practice differ in length, advice, frequency of meetings, staff and cost. Very few real-world programmes have published patient-related outcomes, and those that have published used different ways of reporting the information, making it impossible to compare interventions and further develop the evidence base. Developing a core outcome set for behavioural weight management programmes (BWMPs) for adults with overweight and obesity will allow different BWMPs to be compared and reveal which interventions work best for which members of the population.
Methods and analysis: An expert group, comprised of 40 people who work in, refer to, or attend BWMPs for adults with overweight and obesity, will be asked to decide which outcomes services should report. An online Delphi process will be employed to help the group reach consensus as to which outcomes should be measured and reported, and which definitions/instruments should be used in order to do so. The first stage of the Delphi process (three rounds of questionnaires) will focus on outcomes while the second stage (three additional rounds of questionnaires) will focus on definition/instrument selection.
Ethics and dissemination: Ethical approval for this study has been received from the University of Glasgow College of Medical, Veterinary and Life Sciences Ethics Committee. With regard to disseminating results, a report will be submitted to our funding body, the Chief Scientist Office of the Scottish Government Health Department. In addition, early findings will be shared with Public Health England and Health Scotland, and results communicated via conference presentations, peer review publication and our institutions’ social media platforms
Air quality simulations for London using a coupled regional-to-local modelling system
A coupled regional-to-local modelling system comprising a regional chemistry–climate model with 5km horizontal resolution (EMEP4UK) and an urban dispersion and chemistry model with explicit road source emissions (ADMS-Urban) has been used to simulate air quality in 2012 across London. The study makes use of emission factors for NOx and NO2 and non-exhaust emission rates of PM10 and PM2.5 which have been adjusted compared to standard factors to reflect real-world emissions, with increases in total emissions of around 30% for these species. The performance of the coupled model and each of the two component models is assessed against measurements from background and near-road sites in London using a range of metrics concerning annual averages, high hourly average concentrations and diurnal cycles. The regional model shows good performance compared to measurements for background sites for these metrics, but under-predicts concentrations of all pollutants except O3 at near-road sites due to the low resolution of input emissions and calculations. The coupled model shows good performance at both background and near-road sites, which is broadly comparable with that of the urban model that uses measured concentrations as regional background, except for PM2.5 where the under-prediction of the regional model causes the coupled model to also under-predict concentrations. Using the coupled model, it is estimated that 13% of the area of London exceeded the EU limit value of 40µgm−3 for annual average NO2 in 2012, whilst areas of exceedances of the annual average limit values of 40 and 25µgm−3 for PM10 and PM2.5 respectively were negligible
Dead or Alive: Use of Elemental Analysis to Determine Status of Stranded Perinate Bottlenose Dolphins (Tursiops truncatus)
Disease associated polymorphisms within the conserved ECR1 enhancer differentially regulate the tissue specific activity of the cannabinoid‐1 receptor gene promoter; implications for cannabinoid pharmacogenetics
EH was funded by Medical Research Scotland (PhD-719-2013) and GW Pharmaceuticals. AMcE was funded by BBSRC project grant (BB/N017544/1). PB and DW are funded by the Scottish Government Rural and Environment Science and Analytical Services Division to the Rowett Institute. The authors declare no conflicts of interest.Peer reviewedPublisher PD
Applying air pollution modelling within a multi-criteria decision analysis framework to evaluate UK air quality policies
A decision support system for evaluating UK air quality policies is presented. It combines the output from a chemistry transport model, a health impact model and other impact models within a multi-criteria decision analysis (MCDA) framework. As a proof-of-concept, the MCDA framework is used to evaluate and compare idealized emission reduction policies in four sectors (combustion in energy and transformation industries, non-industrial combustion plants, road transport and agriculture) and across six outcomes or criteria (mortality, health inequality, greenhouse gas emissions, biodiversity, crop yield and air quality legal compliance). To illustrate a realistic use of the MCDA framework, the relative importance of the criteria were elicited from a number of stakeholders acting as proxy policy makers. In the prototype decision problem, we show that reducing emissions from industrial combustion (followed very closely by road transport and agriculture) is more advantageous than equivalent reductions from the other sectors when all the criteria are taken into account. Extensions of the MCDA framework to support policy makers in practice are discussed
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Mesozoic Diversity of Osmundaceae: Osmundacaulis whittlesii sp. nov. in the Early Cretaceous of Western Canada
Premise of research: A distinctive new species of osmundaceous fern, based on a permineralized trunk from
Lower Cretaceous deposits of Haida Gwaii (formerly the Queen Charlotte Islands) off the west coast of mainland
Canada, provides additional data for addressing the Mesozoic diversity and the overall pattern of phylogeny
for osmundaceous filicalean ferns.
Methodology: The specimen was cut into segments and studied from both external morphology and anatomical
sections prepared by the cellulose acetate peel technique. Microscope slides of sections were examined,
and images were captured under transmitted light.
Pivotal results: The fossil represents a new species of Osmundacaulis, which is only the third Northern
Hemisphere representative of this predominantly Southern Hemisphere genus.
Conclusions: Osmundacaulis whittlesii sp. nov. increases the Northern Hemisphere diversity of Cretaceous
Osmundaceae, thus providing new data about Mesozoic diversity of the clade, potential sister-group relationships
of crown-group Osmundaceae, and the overall pattern of phylogeny for Osmundaceae.This is the publisher’s final pdf. The published article is copyrighted by the University of Chicago Press and can be found at: http://www.jstor.org/action/showPublication?journalCode=intejplanscie.Keywords: Osmundacaulis, Mesozoic, Haida Gwaii, Albian, Osmundaceae, Early Cretaceou
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