141 research outputs found

    Combined TRPC3 and TRPC6 blockade by selective small-molecule or genetic deletion inhibits pathological cardiac hypertrophy

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    Chronic neurohormonal and mechanical stresses are central fea-tures of heart disease. Increasing evidence supports a role forthe transient receptor potential canonical channels TRPC3 andTRPC6 in this pathophysiology. Channel expression for both is nor-mally very low but is increased by cardiac disease, and geneticgain- or loss-of-function studies support contributions to hypertro-phy and dysfunction. Selective small-molecule inhibitors remainscarce, and none target both channels, which may be useful giventhe high homology among them and evidence of redundant sig-naling. Here we tested selective TRPC3/6 antagonists (GSK2332255Band GSK2833503A; IC50,3–21 nM against TRPC3 and TRPC6) andfound dose-dependent blockade of cell hypertrophy signaling trig-gered by angiotensin II or endothelin-1 in HEK293T cells as well as inneonatal and adult cardiac myocytes. In vivo efficacy in mice andrats was greatly limited by rapid metabolism and high protein bind-ing, although antifibrotic effects with pressure overload were ob-served. Intriguingly, although gene deletion of TRPC3 or TRPC6alone did not protect against hypertrophy or dysfunction frompressure overload, combined deletion was protective, support-ing the value of dual inhibition. Further development of thispharmaceutical class may yield a useful therapeutic agent forheart disease management.Fil: Seo, Kinya. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Rainer, Peter P.. Johns Hopkins Medical Institutions. Department of Medicine; Estados Unidos. Medical University of Graz. Department of Medicine; AustriaFil: Shalkey Hahn, Virginia. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Lee, Dong-ik. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Jo, Su-Hyun. Kangwon National University School of Medicine; Corea del Sur. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Andersen, Asger. Aarhus University Hospital. Department of Cardiology; DinamarcaFil: Liu, Ting. Johns Hopkins Medical Institutions. Department of Medicine; Estados UnidosFil: Xu, Xiaoping. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Willette, Robert N.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Lepore, John J.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Marino, Joseph P.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Birnbaumer, Lutz. ational Institute of Environmental Health Sciences; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Schnackenberg, Christine G.. GlaxoSmithKline Heart Failure Discovery Performance Unit; Estados UnidosFil: Kass, David A.. Johns Hopkins Medical Institutions. Department of Medicine; Estados Unido

    Interleukin-6 gene (IL-6): a possible role in brain morphology in the healthy adult brain

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    Background: Cytokines such as interleukin 6 (IL-6) have been implicated in dual functions in neuropsychiatric disorders. Little is known about the genetic predisposition to neurodegenerative and neuroproliferative properties of cytokine genes. In this study the potential dual role of several IL-6 polymorphisms in brain morphology is investigated. Methodology: In a large sample of healthy individuals (N = 303), associations between genetic variants of IL-6 (rs1800795; rs1800796, rs2069833, rs2069840) and brain volume (gray matter volume) were analyzed using voxel-based morphometry (VBM). Selection of single nucleotide polymorphisms (SNPs) followed a tagging SNP approach (e.g., Stampa algorigthm), yielding a capture 97.08% of the variation in the IL-6 gene using four tagging SNPs. Principal findings/results: In a whole-brain analysis, the polymorphism rs1800795 (−174 C/G) showed a strong main effect of genotype (43 CC vs. 150 CG vs. 100 GG; x = 24, y = −10, z = −15; F(2,286) = 8.54, puncorrected = 0.0002; pAlphaSim-corrected = 0.002; cluster size k = 577) within the right hippocampus head. Homozygous carriers of the G-allele had significantly larger hippocampus gray matter volumes compared to heterozygous subjects. None of the other investigated SNPs showed a significant association with grey matter volume in whole-brain analyses. Conclusions/significance: These findings suggest a possible neuroprotective role of the G-allele of the SNP rs1800795 on hippocampal volumes. Studies on the role of this SNP in psychiatric populations and especially in those with an affected hippocampus (e.g., by maltreatment, stress) are warranted.Bernhard T Baune, Carsten Konrad, Dominik Grotegerd, Thomas Suslow, Eva Birosova, Patricia Ohrmann, Jochen Bauer, Volker Arolt, Walter Heindel, Katharina Domschke, Sonja Schöning, Astrid V Rauch, Christina Uhlmann, Harald Kugel and Udo Dannlowsk

    In Vitro and In Vivo Characterization of Intrinsic Sympathomimetic Activity in Normal and Heart Failure Rats

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    ABSTRACT Clinical studies conducted with carvedilol suggest that ␤-adrenoceptor antagonism is an effective therapeutic approach to the treatment of heart failure. However, many ␤-adrenoceptor antagonists are weak partial agonists and possess significant intrinsic sympathomimetic activity (ISA), which may be problematic in the treatment of heart failure. In the present study, the ISAs of bucindolol, xamoterol, bisoprolol, and carvedilol were evaluated and compared in normal rats [Sprague-Dawley (SD)], in rats with confirmed heart failure [spontaneously hypertensive heart failure (SHHF)], and in isolated neonatal rat cardiomyocytes. At equieffective ␤ 1 -adrenolytic doses, the administration of xamoterol and bucindolol produced a prolonged, equieffective, and dose-related increase in heart rate in both pithed SD rats (ED 50 ϭ 5 and 40 g/kg, respectively) and SHHF rats (ED 50 ϭ 6 and 30 g/kg, respectively). The maximum effect of both compounds in SHHF rats was approximately 50% of that observed in SD rats. In contrast, carvedilol and bisoprolol had no significant effect on resting heart rate in the pithed SD or SHHF rat. The maximum increase in heart rate elicited by xamoterol and bucindolol was inhibited by treatment with propranolol, carvedilol, and betaxolol (␤ 1 -adrenoceptor antagonist) but not by ICI 118551 (␤ 2 -adrenoceptor antagonist) in neonatal rat. When the ␤-adrenoceptor-mediated cAMP response was examined in cardiomyocytes, an identical partial agonist/antagonist response profile was observed for all compounds, demonstrating a strong correlation with the in vivo results. In contrast, GTP-sensitive ligand binding and tissue adenylate cyclase activity were not sensitive methods for detecting ␤-adrenoceptor partial agonist activity in the heart. In summary, xamoterol and bucindolol, but not carvedilol and bisoprolol, exhibited direct ␤ 1 -adrenoceptor-mediated ISA in normal and heart failure rats

    Adiposity is Associated with Regional Cortical Thinning

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    BACKGROUND: Although obesity is associated with structural changes in brain grey matter, findings have been inconsistent and the precise nature of these changes is unclear. Inconsistencies may partly be due to the use of different volumetric morphometry methods, and the inclusion of participants with comorbidities that exert independent effects on brain structure. The latter concern is particularly critical when sample sizes are modest. The purpose of the current study was to examine the relationship between cortical grey matter and body mass index (BMI), in healthy participants, excluding confounding comorbidities and using a large sample size. SUBJECTS: A total of 202 self-reported healthy volunteers were studied using surface-based morphometry, which permits the measurement of cortical thickness, surface area and cortical folding, independent of each other. RESULTS: Although increasing BMI was not associated with global cortical changes, a more precise, region-based analysis revealed significant thinning of the cortex in two areas: left lateral occipital cortex (LOC) and right ventromedial prefrontal cortex (vmPFC). An analogous region-based analysis failed to find an association between BMI and regional surface area or folding. Participants' age was also found to be negatively associated with cortical thickness of several brain regions; however, there was no overlap between the age- and BMI-related effects on cortical thinning. CONCLUSIONS: Our data suggest that the key effect of increasing BMI on cortical grey matter is a focal thinning in the left LOC and right vmPFC. Consistent implications of the latter region in reward valuation, and goal control of decision and action suggest a possible shift in these processes with increasing BMI.We thank all the participants and the staff of the Wolfson Brain Imaging Centre. This work was supported by the Bernard Wolfe Health Neuroscience Fund (NM, HZ, ISF, PCF), the Wellcome Trust (RGAG/144 to N.M, RGAG/188 to ISF, RNAG/259 to PCF) and the Medical Research Council (G0701497 to KDE).This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/ijo.2016.42

    Inhibition of p38 MAPK Suppresses Inflammatory Cytokine Induction by Etoposide, 5-Fluorouracil, and Doxorubicin without Affecting Tumoricidal Activity

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    Cancer patients undergoing treatment with systemic cancer chemotherapy drugs often experience debilitating fatigue similar to sickness behavior, a normal response to infection or tissue damage caused by the production of the inflammatory cytokines IL-1β, TNF-α, and IL-6. The p38 mitogen activated protein kinase (p38 MAPK) plays a central role in the production of these cytokines and consequently the development of sickness behavior. Targeted inhibitors of p38 MAPK can reduce systemic inflammatory cytokine production and the development of sickness behavior. Several systemic cancer chemotherapy drugs have been shown to stimulate inflammatory cytokine production, yet whether this response is related to a common ability to activate p38 MAPK is not known and is the focus of this study. This understanding may present the possibility of using p38 MAPK inhibitors to reduce chemotherapy-induced inflammatory cytokine production and consequently treatment-related fatigue. One caveat of this approach is a potential reduction in chemotherapeutic efficacy as some believe that p38 MAPK activity is required for chemotherapy-induced cytotoxicity of tumor cells. The purpose of this study was to demonstrate proof of principal that p38 MAPK inhibition can block chemotherapy- induced inflammatory cytokine production without inhibiting drug-induced cytotoxicity using murine peritoneal macrophages and Lewis Lung Carcinoma (LLC1) cells as model cell systems. Using these cells we assessed the requirement of etoposide, doxorubicin, 5-flourouracil, and docetaxel for p38 MAPK in inflammatory cytokine production and cytotoxicity. Study findings demonstrate that clinically relevant doses of etoposide, doxorubicin, and 5-FU activated p38 MAPK in both macrophages and LLC1 cells. In contrast, docetaxel failed to activate p38 MAPK in either cell type. Activation of p38 MAPK mediated the drug's effects on inflammatory cytokine production in macrophages but not LLC1 cytotoxicity and this was confirmed with inhibitor studies

    Hyperglycemia and Diabetes Downregulate the Functional Expression of TRPV4 Channels in Retinal Microvascular Endothelium

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    Retinal endothelial cell dysfunction is believed to play a key role in the etiology and pathogenesis of diabetic retinopathy. Numerous studies have shown that TRPV4 channels are critically involved in maintaining normal endothelial cell function. In the current paper, we demonstrate that TRPV4 is functionally expressed in the endothelium of the retinal microcirculation and that both channel expression and activity is downregulated by hyperglycaemia. Quantitative PCR and immunostaining demonstrated molecular expression of TRPV4 in cultured bovine retinal microvascular endothelial cells (RMECs). Functional TRPV4 activity was assessed in cultured RMECs from endothelial Ca2+-responses recorded using fura-2 microfluorimetry and electrophysiological recordings of membrane currents. The TRPV4 agonist 4α-phorbol 12,13-didecanoate (4-αPDD) increased [Ca2+]i in RMECs and this response was largely abolished using siRNA targeted against TRPV4. These Ca2+-signals were completely inhibited by removal of extracellular Ca2+, confirming their dependence on influx of extracellular Ca2+. The 4-αPDD Ca2+-response recorded in the presence of cyclopiazonic acid (CPA), which depletes the intracellular stores preventing any signal amplification through store release, was used as a measure of Ca2+-influx across the cell membrane. This response was blocked by HC067047, a TRPV4 antagonist. Under voltage clamp conditions, the TRPV4 agonist GSK1016790A stimulated a membrane current, which was again inhibited by HC067047. Following incubation with 25 mM D-glucose TRPV4 expression was reduced in comparison with RMECs cultured under control conditions, as were 4αPDD-induced Ca2+-responses in the presence of CPA and ion currents evoked by GSK1016790A. Molecular expression of TRPV4 in the retinal vascular endothelium of 3 months' streptozotocin-induced diabetic rats was also reduced in comparison with that in age-matched controls. We conclude that hyperglycaemia and diabetes reduce the molecular and functional expression of TRPV4 channels in retinal microvascular endothelial cells. These changes may contribute to diabetes induced endothelial dysfunction and retinopathy

    The Role of Tourism and Recreation in the Spread of Non-Native Species: A Systematic Review and Meta-Analysis

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    Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor recreation involve the frequent congregation of people, vehicles and vessels from geographically diverse areas. They are therefore perceived to be major pathways for the movement of non-native species, and ones that will become increasingly important with the continued growth of these sectors. However, a global assessment of the relationship between tourism activities and the introduction of non-native species–particularly in freshwater and marine environments–is lacking. We conducted a systematic review and meta-analysis to determine the impact of tourism and outdoor recreation on non-native species in terrestrial, marine and freshwater environments. Our results provide quantitative evidence that the abundance and richness of non-native species are significantly higher in sites where tourist activities take place than in control sites. The pattern was consistent across terrestrial, freshwater and marine environments; across a variety of vectors (e.g. horses, hikers, yachts); and across a range of taxonomic groups. These results highlight the need for widespread biosecurity interventions to prevent the inadvertent introduction of invasive non-native species (INNS) as the tourism and outdoor recreation sectors grow

    Методология синтеза архитектуры программно-технического комплекса автоматизированной системы мониторинга обстановки

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    Предложен подход к проектированию архитектуры программно-технического комплекса автоматизированной системы мониторинга обстановки в реальном времени, основанный на классификации решаемых функциональных задач на основе методов кластерного анализа и выбранного множества признаков подобия. Разработанный подход позволяет из множества функций системы выделить подобные (по определенным признакам) и объединить их в архитектурные компоненты (унифицированные функциональные модули).Запропоновано підхід до проектування архітектури центру обробки інформації автоматизованої системи моніторингу середовища в реальному часі, що заснований на класифікації функціональних задач на підставі методів кластерного аналізу і обраної множини ознак схожості. Розроблений підхід дозволяє вибрати із множини функцій системи схожі (за певними ознаками) і поєднати їх в архітектурні компоненти (уніфіковані функціональні модулі).The approach to designing architecture of the information processing complex of the automated real time conditions monitoring system based on classification of functional tasks on the basis of methods of cluster analysis and the chosen set of similarity attributes is offered. The developed approach allows to allocate from a set of functions the systems similar (on certain attributes) and to unite them in architectural components (unified functional modules)
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