107 research outputs found

    Liver fibrosis secondary to bile duct injury: correlation of Smad7 with TGF-β and extracellular matrix proteins

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    <p>Abstract</p> <p>Background</p> <p>Liver fibrosis is the result of continuous liver injury stemming from different etiological factors. Bile duct injury induces an altered expression of TGF-β, which has an important role in liver fibrosis because this cytokine induces the expression of target genes such as collagens, PAI-1, TIMPs, and others that lead to extracellular matrix deposition. Smad7 is the principal inhibitor that regulates the target gene transcription of the TGF-β signaling. The aim of the study was to determine whether Smad7 mRNA expression correlates with the gene expression of <it>TGF-β, Col I</it>, <it>Col III</it>, <it>Col IV</it>, or <it>PAI-1 </it>in liver fibrosis secondary to bile duct injury (BDI).</p> <p>Results</p> <p>Serum TGF-β concentration was higher in BDI patients (39 296 pg/ml) than in liver donors (9008 pg/ml). Morphometric analysis of liver sections showed 41.85% of tissue contained fibrotic deposits in BDI patients. mRNA expression of Smad7, Col I, and PAI-1 was also significantly higher (<it>P </it>< 0.05) in patients with BDI than in controls. Smad7 mRNA expression correlated significantly with TGF-β concentration, Col I and Col III expression, and the amount of fibrosis.</p> <p>Conclusion</p> <p>We found augmented serum concentration of TGF-β and an increase in the percentage of fibrotic tissue in the liver of BDI patients. Contrary to expected results, the 6-fold increase in <it>Smad7 </it>expression did not inhibit the expression of <it>TGF-β, collagens</it>, and <it>PAI-1</it>. We also observed greater expression of Col I and Col III mRNA in BDI patients and significant correlations between their expression and TGF-β concentration and Smad7 mRNA expression.</p

    Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

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    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at sNN\sqrt{s_{_{\rm NN}}} = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in η<0.8|\eta|<0.8 and 0.3<pT<200.3 < p_T < 20 GeV/cc are compared to the expectation in pp collisions at the same sNN\sqrt{s_{\rm NN}}, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAAR_{\rm AA}. The result indicates only weak medium effects (RAAR_{\rm AA} \approx 0.7) in peripheral collisions. In central collisions, RAAR_{\rm AA} reaches a minimum of about 0.14 at pT=6p_{\rm T}=6-7GeV/cc and increases significantly at larger pTp_{\rm T}. The measured suppression of high-pTp_{\rm T} particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

    Strange particle production in proton-proton collisions at s=0.9\sqrt{s}=0.9 TeV with ALICE at the LHC

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    The production of mesons containing strange quarks (Ks0^0_s, ϕ\phi) and both singly and doubly strange baryons (Λ\Lambda, Anti-Λ\Lambda, and Ξ\Xi+Anti-Ξ\Xi) are measured at central rapidity in pp collisions at s\sqrt{s} = 0.9 TeV with the ALICE experiment at the LHC. The results are obtained from the analysis of about 250 k minimum bias events recorded in 2009. Measurements of yields (dN/dy) and transverse momentum spectra at central rapidities for inelastic pp collisions are presented. For mesons, we report yields () of 0.184 ±\pm 0.002 stat. ±\pm 0.006 syst. for Ks0^0_s and 0.021 ±\pm 0.004 stat. ±\pm 0.003 syst. for ϕ\phi. For baryons, we find = 0.048 ±\pm 0.001 stat. ±\pm 0.004 syst. for Λ\Lambda, 0.047 ±\pm 0.002 stat. ±\pm 0.005 syst. for Anti-Λ\Lambda and 0.0101 ±\pm 0.0020 stat. ±\pm 0.0009 syst. for Ξ\Xi+Anti-Ξ\Xi. The results are also compared with predictions for identified particle spectra from QCD-inspired models and provide a baseline for comparisons with both future pp measurements at higher energies and heavy-ion collisions.Comment: 33 pages, 21 captioned figures, 10 tables, authors from page 28, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/387

    Magnesium accumulation upon cyclin M4 silencing activates microsomal triglyceride transfer protein improving NASH

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    Background & Aims: Perturbations of intracellular magnesium (Mg) homeostasis have implications for cell physiology. The cyclin M family, CNNM, perform key functions in the transport of Mg across cell membranes. Herein, we aimed to elucidate the role of CNNM4 in the development of non-alcoholic steatohepatitis (NASH). Methods: Serum Mg levels and hepatic CNNM4 expression were characterised in clinical samples. Primary hepatocytes were cultured under methionine and choline deprivation. A 0.1% methionine and choline-deficient diet, or a choline-deficient high-fat diet were used to induce NASH in our in vivo rodent models. Cnnm4 was silenced using siRNA, in vitro with DharmaFECT and in vivo with Invivofectamine® or conjugated to N-acetylgalactosamine. Results: Patients with NASH showed hepatic CNNM4 overexpression and dysregulated Mg levels in the serum. Cnnm4 silencing ameliorated hepatic lipid accumulation, inflammation and fibrosis in the rodent NASH models. Mechanistically, CNNM4 knockdown in hepatocytes induced cellular Mg accumulation, reduced endoplasmic reticulum stress, and increased microsomal triglyceride transfer activity, which promoted hepatic lipid clearance by increasing the secretion of VLDLs. Conclusions: CNNM4 is overexpressed in patients with NASH and is responsible for dysregulated Mg transport. Hepatic CNNM4 is a promising therapeutic target for the treatment of NASH. Lay summary: Cyclin M4 (CNNM4) is overexpressed in non-alcoholic steatohepatitis (NASH) and promotes the export of magnesium from the liver. The liver-specific silencing of Cnnm4 ameliorates NASH by reducing endoplasmic reticulum stress and promoting the activity of microsomal triglyceride transfer protein.Ministerio de Ciencia e Innovación, Programa Retos-Colaboración RTC2019-007125-1 (for JS and MLM-C); Instituto de Salud Carlos III, Proyectos de Investigación en Salud DTS20/00138 (for JS and MLM-C); Departamento de Industria del Gobierno Vasco (for MLM-C); Ministerio de Ciencia, Innovación y Universidades MICINN: SAF2017-87301-R and RTI2018-096759-A-100 integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovación, cofinanciado con Fondos FEDER (for MLM-C and TCD, respectively); BIOEF (Basque Foundation for Innovation and Health Research); EITB Maratoia BIO15/CA/014; Asociación Española contra el Cáncer (MLM-C, TCD); Fundación Científica de la Asociación Española Contra el Cancer (AECC Scientific Foundation) Rare Tumor Calls 2017 (for MLM); La Caixa Foundation Program (for MLM); Fundacion BBVA UMBRELLA project (for MLM); BFU2015-70067-REDC, BFU2016-77408-R, and BES-2017- 080435 (MINECO / FEDER, UE) and the FIGHT-CNNM2 project from the EJP RD Joint Transnational Call (JTC2019) (Ref. AC19/ 00073) (for LAM-C); RTI2018-095134-B-100 and Grupos de Investigación del Sistema Universitario Vasco (IT971-16) (for PA); National Institutes of Health under grant CA217817 (for DB); AGL2014-54585-R, AGL-2017-86927-R and EQC2018-004897-P from MINECO; PC0148-2016-0149 and PAI-BIO311 from Junta de Andalucía (for FM). Ciberehd_ISCIII_MINECO is funded by the Instituto de Salud Carlos III. We thank Silence Therapeutics plc. for the financial support provided. We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV- 2016-0644)

    Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388

    Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η\eta|<0.8) and transverse momentum range 0.2< pTp_{\rm T}< 5.0 GeV/cc. The elliptic flow signal v2_2, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ±\pm 0.002 (stat) ±\pm 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v2(pT)_2(p_{\rm T}) reaches a maximum of 0.2 near pTp_{\rm T} = 3 GeV/cc. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

    Resilient emotionality and molecular compensation in mice lacking the oligodendrocyte-specific gene Cnp1

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    Altered oligodendrocyte structure and function is implicated in major psychiatric illnesses, including low cell number and reduced oligodendrocyte-specific gene expression in major depressive disorder (MDD). These features are also observed in the unpredictable chronic mild stress (UCMS) rodent model of the illness, suggesting that they are consequential to environmental precipitants; however, whether oligodendrocyte changes contribute causally to low emotionality is unknown. Focusing on 2′-3′-cyclic nucleotide 3′-phosphodiesterase (Cnp1), a crucial component of axoglial communication dysregulated in the amygdala of MDD subjects and UCMS-exposed mice, we show that altered oligodendrocyte integrity can have an unexpected functional role in affect regulation. Mice lacking Cnp1 (knockout, KO) displayed decreased anxiety- and depressive-like symptoms (i.e., low emotionality) compared with wild-type animals, a phenotypic difference that increased with age (3–9 months). This phenotype was accompanied by increased motor activity, but was evident before neurodegenerative-associated motor coordination deficits (⩽9–12 months). Notably, Cnp1KO mice were less vulnerable to developing a depressive-like syndrome after either UCMS or chronic corticosterone exposure. Cnp1KO mice also displayed reduced fear expression during extinction, despite normal amygdala c-Fos induction after acute stress, together implicating dysfunction of an amygdala-related neural network, and consistent with proposed mechanisms for stress resiliency. However, the Cnp1KO behavioral phenotype was also accompanied by massive upregulation of oligodendrocyte- and immune-related genes in the basolateral amygdala, suggesting an attempt at functional compensation. Together, we demonstrate that the lack of oligodendrocyte-specific Cnp1 leads to resilient emotionality. However, combined with substantial molecular changes and late-onset neurodegeneration, these results suggest the low Cnp1 seen in MDD may cause unsustainable and maladaptive molecular compensations contributing to the disease pathophysiology

    RyRCa2+ Leak Limits Cardiac Ca2+ Window Current Overcoming the Tonic Effect of Calmodulin in Mice

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    Ca2+ mediates the functional coupling between L-type Ca2+ channel (LTCC) and sarcoplasmic reticulum (SR) Ca2+ release channel (ryanodine receptor, RyR), participating in key pathophysiological processes. This crosstalk manifests as the orthograde Ca2+-induced Ca2+-release (CICR) mechanism triggered by Ca2+ influx, but also as the retrograde Ca2+-dependent inactivation (CDI) of LTCC, which depends on both Ca2+ permeating through the LTCC itself and on SR Ca2+ release through the RyR. This latter effect has been suggested to rely on local rather than global Ca2+ signaling, which might parallel the nanodomain control of CDI carried out through calmodulin (CaM). Analyzing the CICR in catecholaminergic polymorphic ventricular tachycardia (CPVT) mice as a model of RyR-generated Ca2+ leak, we evidence here that increased occurrence of the discrete local SR Ca2+ releases through the RyRs (Ca2+ sparks) causea depolarizing shift in activation and a hyperpolarizing shift inisochronic inactivation of cardiac LTCC current resulting in the reduction of window current. Both increasing fast [Ca2+]i buffer capacity or depleting SR Ca2+ store blunted these changes, which could be reproduced in WT cells by RyRCa2+ leak induced with Ryanodol and CaM inhibition.Our results unveiled a new paradigm for CaM-dependent effect on LTCC gating and further the nanodomain Ca2+ control of LTCC, emphasizing the importance of spatio-temporal relationships between Ca2+ signals and CaM function

    Effects of circadian disruption on physiology and pathology: from bench to clinic (and back)

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    Nested within the hypothalamus, the suprachiasmatic nuclei (SCN) represent a central biological clock that regulates daily and circadian (i.e., close to 24 h) rhythms in mammals. Besides the SCN, a number of peripheral oscillators throughout the body control local rhythms and are usually kept in pace by the central clock. In order to represent an adaptive value, circadian rhythms must be entrained by environmental signals or zeitgebers, the main one being the daily light?dark (LD) cycle. The SCN adopt a stable phase relationship with the LD cycle that, when challenged, results in abrupt or chronic changes in overt rhythms and, in turn, in physiological, behavioral, and metabolic variables. Changes in entrainment, both acute and chronic, may have severe consequences in human performance and pathological outcome. Indeed, animal models of desynchronization have become a useful tool to understand such changes and to evaluate potential treatments in human subjects. Here we review a number of alterations in circadian entrainment, including jet lag, social jet lag (i.e., desynchronization between body rhythms and normal time schedules), shift work, and exposure to nocturnal light, both in human subjects and in laboratory animals. Finally, we focus on the health consequences related to circadian/entrainment disorders and propose a number of approaches for the management of circadian desynchronization.Fil: Chiesa, Juan José. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duhart, José Manuel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Casiraghi, Leandro Pablo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paladino, Natalia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bussi, Ivana Leda. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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