48 research outputs found

    Intracellular Triggering of Fas Aggregation and Recruitment of Apoptotic Molecules into Fas-enriched Rafts in Selective Tumor Cell Apoptosis

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    We have discovered a new and specific cell-killing mechanism mediated by the selective uptake of the antitumor drug 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH3, Edelfosine) into lipid rafts of tumor cells, followed by its coaggregation with Fas death receptor (also known as APO-1 or CD95) and recruitment of apoptotic molecules into Fas-enriched rafts. Drug sensitivity was dependent on drug uptake and Fas expression, regardless of the presence of other major death receptors, such as tumor necrosis factor (TNF) receptor 1 or TNF-related apoptosis-inducing ligand R2/DR5 in the target cell. Drug microinjection experiments in Fas-deficient and Fas-transfected cells unable to incorporate exogenous ET-18-OCH3 demonstrated that Fas was intracellularly activated. Partial deletion of the Fas intracellular domain prevented apoptosis. Unlike normal lymphocytes, leukemic T cells incorporated ET-18-OCH3 into rafts coaggregating with Fas and underwent apoptosis. Fas-associated death domain protein, procaspase-8, procaspase-10, c-Jun amino-terminal kinase, and Bid were recruited into rafts, linking Fas and mitochondrial signaling routes. Clustering of rafts was necessary but not sufficient for ET-18-OCH3–mediated cell death, with Fas being required as the apoptosis trigger. ET-18-OCH3–mediated apoptosis did not require sphingomyelinase activation. Normal cells, including human and rat hepatocytes, did not incorporate ET-18-OCH3 and were spared. This mechanism represents the first selective activation of Fas in tumor cells. Our data set a framework for the development of more targeted therapies leading to intracellular Fas activation and recruitment of downstream signaling molecules into Fas-enriched rafts

    Derangement of body representation in complex regional pain syndrome: report of a case treated with mirror and prisms

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    Perhaps the most intriguing disorders of body representation are those that are not due to primary disease of brain tissue. Strange and sometimes painful phantom limb sensations can result from loss of afference to the brain; and Complex Regional Pain Syndrome (CRPS)—the subject of the current report—can follow limb trauma without pathology of either the central or peripheral nervous system. This enigmatic and vexing condition follows relatively minor trauma, and can result in enduring misery and a useless limb. It manifests as severe pain, autonomic dysfunction, motor disability and ‘neglect-like’ symptoms with distorted body representation. For this special issue on body representation we describe the case of a patient suffering from CRPS, including symptoms suggesting a distorted representation of the affected limb. We report contrasting effects of mirror box therapy, as well as a new treatment—prism adaptation therapy—that provided sustained pain relief and reduced disability. The benefits were contingent upon adapting with the affected limb. Other novel observations suggest that: (1) pain may be a consequence, not the cause, of a disturbance of body representation that gives rise to the syndrome; (2) immobilisation, not pain, may precipitate this reorganisation of somatomotor circuits in susceptible individuals; and (3) limitation of voluntary movement is neither due to pain nor to weakness but, rather, to derangement of body representation which renders certain postures from the repertoire of hand movements inaccessible

    Vitamin D supplementation for the prevention of type 2 diabetes in overweight adults: study protocol for a randomized controlled trial

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    Despite Australia's sunny climate, low vitamin D levels are increasingly prevalent. Sun exposure is limited by long working hours, an increase in time spent indoors, and sun protection practices, and there is limited dietary vitamin D fortification. While the importance of vitamin D for bone mineralization is well known, its role as a protective agent against chronic diseases, such as type 2 diabetes and cardiovascular disease, is less understood. Observational and limited intervention studies suggest that vitamin D might improve insulin sensitivity and secretion, mainly via its anti-inflammatory properties, thereby decreasing the risk of development and progression of type 2 diabetes. The primary aim of this trial is to investigate whether improved plasma concentrations of 25-hydroxyvitamin D (25(OH)D), obtained through vitamin D supplementation, will increase insulin sensitivity and insulin secretion. A secondary aim is to determine whether these relationships are mediated by a reduction in underlying subclinical inflammation associated with obesity.Fifty overweight but otherwise healthy nondiabetic adults between 18 and 60 years old, with low vitamin D levels (25(OH)D < 50 nmol/l), will be randomly assigned to intervention or placebo. At baseline, participants will undergo a medical review and anthropometric measurements, including dual X-ray absorptiometry, an intravenous glucose tolerance test, muscle and fat biopsies, a hyperinsulinemic euglycemic clamp, and questionnaires assessing diet, physical activity, sun exposure, back and knee pain, and depression. The intervention group will receive a first dose of 100,000 IU followed by 4,000 IU vitamin D (cholecalciferol) daily, while the placebo group will receive apparently identical capsules, both for a period of 16 weeks. All measurements will be repeated at follow-up, with the primary outcome measure expressed as a change from baseline in insulin sensitivity and secretion for the intervention group compared with the placebo group. Secondary outcome measures will compare changes in anthropometry, cardiovascular risk factors, and inflammatory markers.The trial will provide much needed clinical evidence on the impact of vitamin D supplementation on insulin resistance and secretion and its underlying mechanisms, which are relevant for the prevention and management of type 2 diabetes.Clinicaltrials.gov ID: NCT02112721 .Barbora de Courten, Aya Mousa, Negar Naderpoor, Helena Teede, Maximilian P J de Courten and Robert Scrag

    Corporate Governance for Sustainability

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    The current model of corporate governance needs reform. There is mounting evidence that the practices of shareholder primacy drive company directors and executives to adopt the same short time horizon as financial markets. Pressure to meet the demands of the financial markets drives stock buybacks, excessive dividends and a failure to invest in productive capabilities. The result is a ‘tragedy of the horizon’, with corporations and their shareholders failing to consider environmental, social or even their own, long-term, economic sustainability. With less than a decade left to address the threat of climate change, and with consensus emerging that businesses need to be held accountable for their contribution, it is time to act and reform corporate governance in the EU. The statement puts forward specific recommendations to clarify the obligations of company boards and directors and make corporate governance practice significantly more sustainable and focused on the long term

    A multimodal cell census and atlas of the mammalian primary motor cortex

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    ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties

    Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions—Ara h2 and Ara h6 Are Readily Bio-Accessible

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    The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted peanut flour was suspended at various pH in buffers mimicking saliva. Protein concentrations and allergens profiles were determined in the supernatants. Peanut protein solubility was poor in the pH range between 3 and 6, while at a low pH (1.5) and at moderately high pHs (\u3e8), it increased. In the pH range of saliva, between 6.5 and 8.5, the allergens Ara h2 and Ara h6 were readily released, whereas Ara h1 and Ara h3 were poorly released. Increasing the pH from 6.5 to 8.5 slightly increased the release of Ara h1 and Ara h3, but the recovery remained low (approximately 20%) compared to that of Ara h2 and Ara h6 (approximately 100% and 65%, respectively). This remarkable difference in the extraction kinetics suggests that Ara h2 and Ara h6 are the first allergens an individual is exposed to upon ingestion of peanut-containing food. We conclude that the peanut allergens Ara h2 and Ara h6 are quickly bio-accessible in the mouth, potentially explaining their extraordinary allergenicity
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