931 research outputs found

    ACID SPHINGOMYELINASE AS A NEW PHARMACOLOGICAL TARGET IN THE ACUTE AND CHRONIC MUSCLE DAMAGE: AN ALTERNATIVE STRATEGY FOR MUSCULAR DYSTROPHIES THERAPY

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    Skeletal muscle inflammation plays a critical role in bridging early muscle injury responses and timely muscle injury recovery (Yang and Hu, 2018). In this study, we investigated the functional role of the sphingolipid-metabolizing enzyme Acid Sphingomyelinase (A-SMase) in the pathophysiology of acute and chronic muscle damage in order to elucidate its role in the establishment of inflammation and in the subsequent muscle regeneration process so that this protein may be proposed as possible therapeutic target. A-SMase is a critical mediator of cell signaling since it is able to generate ceramide from the membrane lipid sphingomyelin thus modulating membrane fluidity, which is determinant in triggering many cellular processes. Several recent studies report the strong relation between high levels of A-SMase expression and inflammatory-associated disorders (Schissel et al., 1998; Devlin et al., 2008; Garcia-Ruiz et al., 2015). In this study, we found that A-SMase expression increases upon induced-acute muscle damage suggesting its involvement in skeletal muscle inflammation. We also demonstrated the importance of A-SMase in regulating the muscle regeneration process following acute muscle damage. Our results showed that A-SMase deficiency leads to an increase of muscle satellite cells, essential for skeletal muscle regeneration, soon after injury, accompanied by a higher number of regenerating myofibers within the injured site. Moreover, two important muscle transcription factors, MyoD and Myogenin, responsible for a correct regeneration were much higher in the absence of A-SMase suggesting that muscle regeneration is accelerated without the hydrolase. In addition, IGF-1, a potent enhancer of tissue regeneration, showed much higher expression levels in absence of A-SMase, consistently with our finding that A-SMase deficiency accelerates the regeneration process. Furthermore, we provide the first evidence of a novel role of A-SMase in regulating macrophage subsets during muscle regeneration demonstrating that A-SMase is able to regulate the polarization of macrophages towards an inflammatory M1 phenotype since its absence leads to an impairment in the expression of M1 macrophage markers. Noteworthy, investigating the role of A-SMase in mdx mice, a mouse model of Duchenne Muscular Dystrophy (DMD), we found an up-regulation of A-SMase in expression and activity in muscles of these mice, that implies its involvement in the pathogenesis of DMD with a particular effect on inflammation. Several studies demonstrated a predominant role of inflammation in the pathogenesis of DMD (Villalta et al., 2009; Radley et al., 2008). Of notice, we observed that the increase of A- SMase in mdx mice paralleled with the increase of muscle inflammatory state. This finding has been further corroborated by the use of the anti-inflammatory drug Naproxcinod that reduced inflammation in mdx muscle and at the same time significantly decreased A-SMase expression and activity. Altogether, our findings open new vistas in the identification of a new potential pharmacological target, A-SMase, in the development and regulation of skeletal muscle inflammation and regeneration process by raising the possibility that the modulation of A-SMase expression levels could bring therapeutic benefits not only in DMD pathology but also in various muscle-wasting diseases

    Development of an adverse outcome pathway for cranio-facial malformations: A contribution from in silico simulations and in vitro data

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    Mixtures of substances sharing the same molecular initiating event (MIE) are supposed to induce additive effects. The proposed MIE for azole fungicides is CYP26 inhibition with retinoic acid (RA) local increase, triggering key events leading to craniofacial defects. Valproic acid (VPA) is supposed to imbalance RA-regulated gene expression trough histone deacetylases (HDACs) inhibition. The aim was to evaluate effects of molecules sharing the same MIE (azoles) and of such having (hypothetically) different MIEs but which are eventually involved in the same adverse outcome pathway (AOP). An in silico approach (molecular docking) investigated the suggested MIEs. Teratogenicity was evaluated in vitro (WEC). Abnormalities were modelled by PROAST software. The common target was the branchial apparatus. In silico results confirmed azole-related CYP26 inhibition and a weak general VPA inhibition on the tested HDACs. Unexpectedly, VPA showed also a weak, but not marginal, capability to enter the CYP 26A1 and CYP 26C1 catalytic sites, suggesting a possible role of VPA in decreasing RA catabolism, acting as an additional MIE. Our findings suggest a new more complex picture. Consequently two different AOPs, leading to the same AO, can be described. VPA MIEs (HDAC and CYP26 inhibition) impinge on the two converging AOPs

    Perturbative expansions from Monte Carlo simulations at weak coupling: Wilson loops and the static-quark self-energy

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    Perturbative coefficients for Wilson loops and the static-quark self-energy are extracted from Monte Carlo simulations at weak coupling. The lattice volumes and couplings are chosen to ensure that the lattice momenta are all perturbative. Twisted boundary conditions are used to eliminate the effects of lattice zero modes and to suppress nonperturbative finite-volume effects due to Z(3) phases. Simulations of the Wilson gluon action are done with both periodic and twisted boundary conditions, and over a wide range of lattice volumes (from 343^4 to 16416^4) and couplings (from ÎČ≈9\beta \approx 9 to ÎČ≈60\beta \approx 60). A high precision comparison is made between the simulation data and results from finite-volume lattice perturbation theory. The Monte Carlo results are shown to be in excellent agreement with perturbation theory through second order. New results for third-order coefficients for a number of Wilson loops and the static-quark self-energy are reported.Comment: 36 pages, 15 figures, REVTEX documen

    Autophagy-mediated neuroprotection induced by octreotide in an ex vivo model of early diabetic retinopathy

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    Neuronal injury plays a major role in diabetic retinopathy (DR). Our hypothesis was that the balance between neuronal death and survival may depend on a similar equilibrium between apoptosis and autophagy and that a neuroprotectant may act by influencing this equilibrium. Ex vivo mouse retinal explants were treated with high glucose (HG) for 10days and the somatostatin analog octreotide (OCT) was used as a neuroprotectant. Chloroquine (CQ) was used as an autophagy inhibitor. Apoptotic and autophagic markers were evaluated using western blot and immunohistochemistry. HG-treated explants displayed a significant increase of apoptosis paralleled by a significant decrease of the autophagic flux, which was likely to be due to increased activity of the autophagy regulator mTOR (mammalian target of rapamycin). Treatment with OCT rescued HG-treated retinal explants from apoptosis and determined an increase of autophagic activity with concomitant mTOR inhibition. Blocking the autophagic flux with CQ completely abolished the anti-apoptotic effect of OCT. Immunohistochemical observations showed that OCT-induced autophagy is localized to populations of bipolar and amacrine cells and to ganglion cells. These observations revealed the antithetic role of apoptosis and autophagy, highlighting their equilibrium from which neuronal survival is likely to depend. These data suggest the crucial role covered by autophagy, which could be considered as a molecular target for DR neuroprotective treatment strategies

    Inflammatory markers and suicidal attempts in depressed patients: A review

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    Major depressive disorder is a chronic and invalidating psychiatric illness and is associated with a greater risk of suicidal behaviors. In recent decades many data have supported a biological link between depressive states and inflammation. Pro-inflammatory cytokines have been found to rise, first of all TNF-α and IL-6. Suicidal behaviors have been consistently associated with increased levels of IL-6 and decreased levels of IL-2. The aim of this review is to investigate the relationship between inflammatory markers in depressed patients with or without suicidal attempts compared to healthy controls

    Design of Multicationic Copper-Bearing Layered Double Hydroxides for Catalytic Application in Biorefinery

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    Ethanol has been used as a renewable hydrogen-donor in the conversion of a lignin model molecule in subcritical conditions. Noble metal-free porous mixed oxides, obtained by activation of Cu-Ni-Al and Cu-Ni-Fe layered double hydroxide (LDH) precursors, have been used as heterogeneous catalysts for Meerwein-Ponndorf-Verley (MPV) hydrogen transfer and further hydrogenation by ethanol dehydrogenation products. Both the Cu/(Cu+Ni) ratio and the nature of the trivalent cation (Al or Fe) affect the activity of the catalysts, as well as the selectivity towards the different steps of the hydrogenation reactions and the cleavage of lignin-like phenylether bonds. Accounting for the peculiar behaviour of Cu2+ and M(III) cations in the synthesis of LDHs, the coprecipitation of the precursors has been monitored by titration experiments. Structural and textural properties of the catalysts are closely related to the composition of the LDH precursors

    Portuguese cacholeira blood sausage: A first taste of its microbiota and volatile organic compounds

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    Among typical Portuguese sausages, the cacholeira blood sausage undoubtedly represents one of the most popular preparations. To the authors’ knowledge, a lack of information on both the microbiota and the volatile organic compounds (VOCs) of this blood-containing sausage emerges from the available scientific literature. This study represents the first characterization of physico-chemical, microbiological and volatile traits of Portuguese cacholeira blood sausage. To this end, ready-to-eat cacholeira blood sausages were collected from two production batches manufactured in summer (batch 1) and autumn (batch 2). Viable counts showed active microbial communities mainly composed by lactic acid bacteria, coagulase negative cocci, enterococci and eumycetes. The metataxonomic approach showed a simple bacterial composition, which was dominated by Lactobacillus sakei in both the analyzed batches (1 and 2) considered. Carnobacterium, Enterococcus, Kluyvera, Lactococcus and Serratia were found as minor genera. The mycobiota varied according to the production season. Batch 1 was dominated by Starmerella apicola, Debaryomyces hansenii and Candida tropicalis, whereas batch 2 was dominated by D. hansenii. Moreover, Aspergillus spp., Kurtzmaniella zeylanoides, Saccharomyces cerevisiae, Kurtzmaniella santamariae, Brettanomyces bruxellensis and Pichia kluyveri were detected in both the batches as minority species. Seventy-two volatile compounds were identified, including esters, phenols, terpenoids, acids, alcohols, ketones, aldehydes, lactones, furans, sulphur and nitrogen compounds. Significant differences were seen in the amount of some compounds, as a feasible consequence of differences in the raw materials, artisan production and seasonality

    GREENET - An Early Stage Training Network in Enabling Technologies for Green Radio

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    International audienceIn this paper, we describe GREENET (an early stage training network in enabling technologies for green radio), which is a new project recently funded by the European Commission under the auspices of the 2010 Marie Curie People Programme. Through the recruitment and personalized training of 17 Early Stage Researchers (ESRs), in GREENET we are committed to the development of new disruptive technologies to address all aspects of energy efficiency in wireless networks, from the user devices to the core network infrastructure, along with the ways the devices and equipment interact with one another. Novel techniques at the physical, link, and network layers to reduce the energy consumption and carbon footprint of 4G devices will be investigated, such as Spatial Modulation (SM) for Multiple-Input-Multiple-Output (MIMO) systems, Cooperative Automatic Repeat reQuest (C-ARQ) protocols, and Network Coding (NC) for lossy networks. Furthermore, cooperation and cognition paradigms will be exploited as additional assets to improve the energy efficiency of wireless networks with the challenging but indispensable constraint of optimizing the system capacity without degrading the user's Quality-of-Service (QoS)

    Comparison of teratogenic potency of azoles using in silico and in vitro methods

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    Craniofacial morphogenesis is affected in rodents by a number of clinical or agrochemical azole fungicides. The hypothesized mode of action of azoles includes abnormal neural crest cell specification and migration from hindbrain to the embryonic branchial region due to retinoic acid (RA) excess. Moreover, the additive effects after the multiple exposure to triazole fungicides account for a common mode of action. In analogy to their antifungal mode of action and hepatic side effects (inhibition of CYP isozymes), the proposed molecular initiating event for azole teratogenicity is the inhibition of embryonic CYP26 isozymes which are key proteins in RA catabolism. Experiments performed on postimplantation rat whole embryo cultures show that all tested azoles are teratogenic at micromolar concentrations, but characterized by different potencies (flusilazole=imazalil=ketoconazole>triadimefon=triadimenol>cyproconazole>tebuconazole>fluconazole). Molecular docking of eight azoles has been performed on CYP26a1, CYP26b1 and CYP26c1 isozymes, which play different roles in their teratogenic outcomes. Different affinities, consistent with the different azole teratogenic profiles and potencies, have been computed, confirming this hypothesis
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