1,612 research outputs found
Influence of Angiotensin II Subtype 2 Receptor (AT2R) Antagonist, PD123319, on Cardiovascular Remodelling of Aged Spontaneously Hypertensive Rats during Chronic Angiotensin II Subtype 1 Receptor (AT1R) Blockade
Cardiac AT2R expression is upregulated in the normal process of aging. In this study we determined the contribution of AT2R to chronic antihypertensive and remodelling effects of AT1R blockade in aged hypertensive rats.
Adult (20 weeks) and senescent (20 months) spontaneously hypertensive rats (SHRs) were treated with either the AT1R antagonist, candesartan cilexetil (2 mg/kg/day), the AT2R antagonist, PD123319 (10 mg/kg/day), or a combination of the 2 compounds.
Mean arterial pressure (MAP) and left ventricular volume were markedly decreased by candesartan cilexetil, however, simultaneous treatment with PD123319 had no additional effect on either parameter. Perivascular fibrosis was significantly reduced by candesartan cilexetil in aged animals only, and this effect was reversed by concomitant PD123319 administration. Vascular hypertrophy was reduced by candesartan cilexetil, and these effects were reversed by simultaneous PD123319.
These results suggest that AT2R stimulation does not significantly influence the antihypertensive effect of chronic AT1R blockade, but plays a role in the regulation of vascular structure. The severe degree of cardiac perivascular fibrosis in senescent animals was regressed by AT1R blockade and this effect was reversed by simultaneous AT2R inhibition, demonstrating an antifibrotic role of AT2R stimulation in the aging hypertensive heart
ELF3 controls thermoresponsive growth in Arabidopsis
Plant development is highly responsive to ambient temperature, and this trait has been linked to the ability of plants to adapt to climate change [1]. The mechanisms by which natural populations modulate their thermoresponsiveness are not known [2]. To address this, we surveyed Arabidopsis accessions for variation in thermal responsiveness of elongation growth and mapped the corresponding loci. We find that the transcriptional regulator EARLY FLOWERING3 (ELF3) controls elongation growth in response to temperature. Through a combination of modeling and experiments, we show that high temperature relieves the gating of growth at night, highlighting the importance of temperature-dependent repressors of growth. ELF3 gating of transcriptional targets responds rapidly and reversibly to changes in temperature. We show that the binding of ELF3 to target promoters is temperature dependent, suggesting a mechanism where temperature directly controls ELF3 activity
Cardioprotective effects in aged spontaneously hypertensive rats due to chronic stimulation/activation of sGC without hypotension
Primate cognition in zoos : reviewing the impact of zoo-based research over 15 years
This work was supported by the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013)/ERC grant agreement no. 609819, SOMICS (EM, EW, ST), UK Economic and Social Research Council studentship 2267016 and the St Leonard’s Research Scholarship from the University of St Andrews (KD).Primate cognition research is reliant on access to members of the study species and logistical infrastructures to conduct observations and experiments. Historically founded in research centers and private collections, and spreading to modern zoos, sanctuaries, and the field, primate cognition has been investigated in diverse settings, each with benefits and challenges. In our systematic review of 12 primatology, animal behavior, and animal cognition journals over the last 15 years, we turn a spotlight on zoos to quantify their current impact on the field and to highlight their potential as robust contributors to future work. To put zoo-based research in context, we compare zoos to three other site types: university-owned or independent research centers, sanctuaries, and field sites. We assess the contributions of zoos across several critical considerations in primate cognition research, including number of investigations, species diversity, sample size, research topic diversity, and methodology. We identified 1,119 publications reporting studies of primate cognition, almost 25% of which report research conducted in zoos. Across publications, zoo-based research has greater species diversity than research centers and covers a diverse range of research topics. Although our review is merely a snapshot of primate cognition research, our findings suggest that zoos may present advantages to researchers regarding species diversity, and lack some of the methodological constraints of field sites, allowing greater ease of access to a diverse range of subjects for cognition investigations. We suggest that zoos have great potential as key contributors for future investigations in primate cognition. Finally, we shed light on the symbiotic relationship that can emerge between researchers and zoos, forming partnerships that bring unique advantages to both parties.Publisher PDFPeer reviewe
Sex-specific influence of angiotensin type 2 receptor stimulation on renal function:a novel therapeutic target for hypertension
Self-management and self-management support outcomes: a systematic review and mixed research synthesis of stakeholder views
Introduction: Self-management has received growing attention as an effective approach for long-term condition management. Little is known about which outcomes of supported self-management are valued by patients, their families, health professionals and those who commission self-management services. This study systematically reviewed published empirical evidence in accordance with PRISMA guidelines to determine the outcomes of self-management valued by these key stakeholder groups, using three prominent exemplar conditions: colorectal cancer, diabetes and stroke.Aim: To systematically review the literature to identify which generic outcomes of self-management have been targeted and are considered important using three exemplar conditions (colorectal cancer, diabetes and stroke), which collectively have a range of features that are likely to be representative of generic self-management issues.Methods: Systematic searching of nine electronic databases was conducted in addition to hand searches of review articles. Abstracts were identified against inclusion criteria and appraised independently by two reviewers, using a critical appraisal tool. Synthesis of findings was conducted using mixed research synthesis.Results: Over 20,536 abstracts were screened. 41 studies which met the review criteria were fully retrieved and appraised. The majority of evidence related to diabetes. Few studies directly focussed on stakeholders’ views concerning desired self-management outcomes; the majority of evidence was derived from studies focusing upon the experience of self-management. The views of health care commissioners were absent from the literature. We identified that self-management outcomes embrace a range of indicators, from knowledge, skills, and bio-psychosocial markers of health through to positive social networks.Conclusions: Patients’, families’, health professionals’ and commissioners’ views regarding which outcomes of self-management are important have not been clearly elicited. The extent to which bio-psychosocial indicators relate to successful self-management from the perspectives of all groups of stakeholders is unknown. Further investigation regarding which self-management outcomes are considered important by all stakeholders is necessary to guide the commissioning and design of future self-management services
Interleukin‐5 drives glycolysis and reactive oxygen species‐dependent citric acid cycling by eosinophils
Introduction
Eosinophils have been long implicated in antiparasite immunity and allergic diseases and, more recently, in regulating adipose tissue homeostasis. The metabolic processes that govern eosinophils, particularly upon activation, are unknown.
Methods
Peripheral blood eosinophils were isolated for the analysis of metabolic processes using extracellular flux analysis and individual metabolites by stable isotope tracer analysis coupled to gas chromatography‐mass spectrometry following treatment with IL‐3, IL‐5 or granulocyte‐macrophage colony‐stimulating factor (GM‐CSF). Eosinophil metabolism was elucidated using pharmacological inhibitors.
Results
Human eosinophils engage a largely glycolytic metabolism but also employ mitochondrial metabolism. Cytokine stimulation generates citric acid cycle (TCA) intermediates from both glucose and glutamine revealing this previously unknown role for mitochondria upon eosinophil activation. We further show that the metabolic programme driven by IL‐5 is dependent on the STAT5/PI3K/Akt signalling axis and that nicotinamide adenine dinucleotide phosphate oxidase (NOX)‐dependent ROS production might be a driver of mitochondrial metabolism upon eosinophil activation.
Conclusion
We demonstrate for the first time that eosinophils are capable of metabolic plasticity, evidenced by increased glucose‐derived lactate production upon ROS inhibition. Collectively, this study reveals a role for both glycolysis and mitochondrial metabolism in cytokine‐stimulated eosinophils. Selective targeting of eosinophil metabolism may be of therapeutic benefit in eosinophil‐mediated diseases and regulation of tissue homeostasis
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