190 research outputs found

    MSK-Mediated Phosphorylation of Histone H3 Ser28 Couples MAPK Signalling with Early Gene Induction and Cardiac Hypertrophy

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    Heart failure is a leading cause of death that develops subsequent to deleterious hypertrophic cardiac remodelling. MAPK pathways play a key role in coordinating the induction of gene expression during hypertrophy. Induction of the immediate early gene (IEG) response including activator protein 1 (AP-1) complex factors is a necessary and early event in this process. How MAPK and IEG expression are coupled during cardiac hypertrophy is not resolved. Here, in vitro, in rodent models and in human samples, we demonstrate that MAPK-stimulated IEG induction depends on the mitogen and stress-activated protein kinase (MSK) and its phosphorylation of histone H3 at serine 28 (pH3S28). pH3S28 in IEG promoters in turn recruits Brg1, a BAF60 ATP-dependent chromatin remodelling complex component, initiating gene expression. Without MSK activity and IEG induction, the hypertrophic response is suppressed. These studies provide new mechanistic insights into the role of MAPK pathways in signalling to the epigenome and regulation of gene expression during cardiac hypertrophy

    Energy substrate metabolism, mitochondrial structure and oxidative stress after cardiac ischemia-reperfusion in mice lacking UCP3.

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    Myocardial ischemia-reperfusion (IR) injury may result in cardiomyocyte dysfunction. Mitochondria play a critical role in cardiomyocyte recovery after IR injury. The mitochondrial uncoupling protein 3 (UCP3) has been proposed to reduce mitochondrial reactive oxygen species (ROS) production and to facilitate fatty acid oxidation. As both mechanisms might be protective following IR injury, we investigated functional, mitochondrial structural, and metabolic cardiac remodeling in wild-type mice and in mice lacking UCP3 (UCP3-KO) after IR. Results showed that infarct size in isolated perfused hearts subjected to IR ex vivo was larger in adult and old UCP3-KO mice than in equivalent wild-type mice, and was accompanied by higher levels of creatine kinase in the effluent and by more pronounced mitochondrial structural changes. The greater myocardial damage in UCP3-KO hearts was confirmed in vivo after coronary artery occlusion followed by reperfusion. S1QEL, a suppressor of superoxide generation from site IQ in complex I, limited infarct size in UCP3-KO hearts, pointing to exacerbated superoxide production as a possible cause of the damage. Metabolomics analysis of isolated perfused hearts confirmed the reported accumulation of succinate, xanthine and hypoxanthine during ischemia, and a shift to anaerobic glucose utilization, which all recovered upon reoxygenation. The metabolic response to ischemia and IR was similar in UCP3-KO and wild-type hearts, being lipid and energy metabolism the most affected pathways. Fatty acid oxidation and complex I (but not complex II) activity were equally impaired after IR. Overall, our results indicate that UCP3 deficiency promotes enhanced superoxide generation and mitochondrial structural changes that increase the vulnerability of the myocardium to IR injury.We are grateful to F. S´ anchez-Madrid, B. Iba´nez ˜ and E. Lara for facilitating experiments at CNIC (Madrid, Spain) and to W.E. Louch for facilitating experiments at the University of Oslo (Oslo, Norway). We thank B. Littlejohns, I. Khaliulin and H. Lin from M.S. Suleiman’s group (University of Bristol, Bristol, UK) for their valuable help with Langendorff perfusion experiments. We also thank E.T. Chouchani from M.P. Murphy’s group (Cambridge, UK) for help with metabolomics analysis, M. Guerra of the Electron Microscopy Unit at CBMSO (Madrid, Spain) for processing the samples for electron microscopy analysis, and A.V. Alonso (CNIC) for echocardiography analyses. The work in our laboratory is funded the Instituto de Salud Carlos III (FIS PI19/01030) to SC. Institutional grants from the Fundacion ´ Ramon ´ Areces and Banco de Santander to the CBMSO are also acknowledged.S

    The dead shall be raised : Multidisciplinary analysis of human skeletons reveals complexity in 19th century immigrant socioeconomic history and identity in New Haven, Connecticut

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    In July 2011, renovations to Yale-New Haven Hospital inadvertently exposed the cemetery of Christ Church, New Haven, Connecticut’s first Catholic cemetery. While this cemetery was active between 1833 and 1851, both the church and its cemetery disappeared from public records, making the discovery serendipitous. Four relatively well-preserved adult skeletons were recovered with few artifacts. All four individuals show indicators of manual labor, health and disease stressors, and dental health issues. Two show indicators of trauma, with the possibility of judicial hanging in one individual. Musculoskeletal markings are consistent with physical stress, and two individuals have arthritic indicators of repetitive movement/specialized activities. Radiographic analyses show osteopenia, healed trauma, and other pathologies in several individuals. Dental calculus analysis did not identify any tuberculosis indicators, despite osteological markers. Isotopic analyses of teeth indicate that all four were likely recent immigrants to the Northeastern United States. Nuclear and mitochondrial DNA were recovered from three individuals, and these analyses identified ancestry, hair/eye color, and relatedness. Genetic and isotopic results upended our initial ancestry assessment based on burial context alone. These individuals provide biocultural evidence of New Haven’s Industrial Revolution and the plasticity of ethnic and religious identity in the immigrant experience. Their recovery and the multifaceted analyses described here illuminate a previously undescribed part of the city’s rich history. The collective expertise of biological, geochemical, archaeological, and historical researchers interprets socioeconomic and cultural identity better than any one could alone. Our combined efforts changed our initial assumptions of a poor urban Catholic cemetery’s membership, and provide a template for future discoveries and analyses

    Agents increasing cyclic GMP amplify 5-HT4-elicited positive inotropic response in failing rat cardiac ventricle

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    Activation of 5-HT4 receptors in failing ventricles elicits a cAMP-dependent positive inotropic response which is mainly limited by the cGMP-inhibitable phosphodiesterase (PDE) 3. However, PDE4 plays an additional role which is demasked by PDE3 inhibition. The objective of this study was to evaluate the effect of cGMP generated by particulate and soluble guanylyl cyclase (GC) on the 5-HT4-mediated inotropic response. Extensive myocardial infarctions were induced by coronary artery ligation in Wistar rats, exhibiting heart failure 6 weeks after surgery. Contractility was measured in left ventricular preparations. Cyclic GMP was measured by EIA. In ventricular preparations, ANP or BNP displayed no impact on 5-HT4-mediated inotropic response. However, CNP increased the 5-HT4-mediated inotropic response as well as the β1-adrenoceptor (β1-AR)-mediated response to a similar extent as PDE3 inhibition by cilostamide. Pretreatment with cilostamide eliminated the effect of CNP. Inhibition of nitric oxide (NO) synthase and soluble GC by l-NAME and ODQ, respectively, attenuated the 5-HT4-mediated inotropic response, whereas the NO donor Sin-1 increased this response. The effects were absent during PDE3 inhibition, suggesting cGMP-dependent inhibition of PDE3. However, in contrast to the effects on the 5-HT4 response, Sin-1 inhibited whereas l-NAME and ODQ enhanced the β1-AR-mediated inotropic response. cGMP generated both by particulate (NPR-B) and soluble GC increases the 5-HT4-mediated inotropic response in failing hearts, probably through inhibition of PDE3. β1-AR and 5-HT4 receptor signalling are subject to opposite regulatory control by cGMP generated by soluble GC in failing hearts. Thus, cGMP from different sources is functionally compartmented, giving differential regulation of different Gs-coupled receptors

    JETSET: Physics at LEAR with an Internal Gas Jet Target and an Advanced General Purpose Detector

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    ABSTRACT We argue the importance of installing at LEAR an internal gas jet target together with a powerful detection system. We discuss an advanced detector which will offer large acceptance and complete information on charged and neutral tracks, in its final implementation. We propose here a phase 1 realisation of this detector which will allow us to carry out a set of fundamental experiments at LEAR during the early operation of ACOL. They comprise studies of .p.p and K\K O s production, on both Wlpolarized and polarized hydrogen targets, over the range 1960 < .Js < 2400 :vleV

    Changes in Intracellular Na+ following Enhancement of Late Na+ Current in Virtual Human Ventricular Myocytes

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    The slowly inactivating or late Na+ current, INa-L, can contribute to the initiation of both atrial and ventricular rhythm disturbances in the human heart. However, the cellular and molecular mechanisms that underlie these pro-arrhythmic influences are not fully understood. At present, the major working hypothesis is that the Na+ influx corresponding to I(Na-L)significantly increases intracellular Na+, [Na]; and the resulting reduction in the electrochemical driving force for Na+ reduces and (may reverse) Na+/Ca2+ exchange. These changes increase intracellular Ca2+, [Ca2+]; which may further enhance I(Na-L)due to calmodulindependent phosphorylation of the Na+ channels. This paper is based on mathematical simulations using the O'Hara et al (2011) model of baseline or healthy human ventricular action potential waveforms(s) and its [Ca2(+)]; homeostasis mechanisms. Somewhat surprisingly, our results reveal only very small changes (<= 1.5 mM) in [Na] even when INa-L is increased 5-fold and steady-state stimulation rate is approximately 2 times the normal human heart rate (i.e. 2 Hz). Previous work done using well-established models of the rabbit and human ventricular action potential in heart failure settings also reported little or no change in [Na] when I(Na-L)was increased. Based on our simulations, the major short-term effect of markedly augmenting I(Na-L)is a significant prolongation of the action potential and an associated increase in the likelihood of reactivation of the L-type Ca2+ current, Ica-L. Furthermore, this action potential prolongation does not contribute to [Na]; increase.This work was supported by (i) the "VI Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica" from the Ministerio de Economia y Competitividad of Spain (grant number TIN2012-37546-C03-01) and the European Commission (European Regional Development Funds-ERDF-FEDER), (ii) by the Direccion General de Politica Cientifica de la Generalitat Valenciana (grant number GV/2013/119), and by (iii), Programa Prometeo (PROMETEO/2016/088) de la Conselleria d'Educacio Formacio I Ocupacio, Generalitat Valenciana. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.K Cardona; TrĂŠnor Gomis, BA.; W Giles (2016). Changes in Intracellular Na+ following Enhancement of Late Na+ Current in Virtual Human Ventricular Myocytes. PLoS ONE. 11(11). https://doi.org/10.1371/journal.pone.0167060S111

    Metabolizam anorganskog olova u profesionalno eksponiranih ljudi

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    Decay rates of blood lead levels in 29 lead workers after end of exposure were analysed mathematically with an exponential two-compartment model. The slow pool had a median half-time of about 5 years, the fast one about one month, but with a considerable inter-individual variation. Lead levels in finger-bone, as determined in 73 active and retired workers by an X-ray fluorescence method, ranged from less than 20 up to 135 mg/kg. There was an increase of finger-bone lead level with increasing exposure time (maximum about 10 mg/kg/year), but the variation between individuals was considerable. In retired workers there was an association between lead levels in finger-bone and blood; an increase of 100-150 mg/kg corresponded to about 1.5 µmol/l. Bone lead levels in biopsies from vertebral spinous processes of 28 lead workers were often lower or higher than in finger-bone, suggesting at least two bone lead pools. Lead level in bone may be practically useful to determine the extent of »internal« lead exposure by mobilization from the skeleton.Napravljena je matematička analiza smanjenja razine olova u 29 radnika pomoću modela s dva kompartmenta. Spori dio kompartmenta imao je vrijeme polovičnog nestanka od otprilike pet godina, a brzi od otprilike jedan mjesec. Postojale su značajne individualne varijacije. Razina olova u falangama kretala se između 20 i 135 mg/kg, kao što je utvrđeno fluorescentnom metodom s X-zrakama u 73 aktivna i umirovljena radnika. Razina olova u kosti rasla je s vremenom ekspozicije s maksimumom od 10 mg/kg. U umirovljenih radnika postojala je povezanost između koncentracije olova u kosti i one u krvi. Povećanje od 100 do 150 mg/kg u kosti odgovaralo je otprilike 1.5 µmol/L. Koncentracija olova u spinalnim nastavcima kralješaka bila je često veća ili manja od one u falangama, što upućuje na postojanje barem dvaju kompartmenta. Razina olova u kosti može poslužiti u praktične svrhe za procjenu moguće interne ekspozicije olovu mobiliziranjem iz skeleta
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