61 research outputs found

    New Modularity of DAP-Kinases: Alternative Splicing of the DRP-1 Gene Produces a ZIPk-Like Isoform

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    DRP-1 and ZIPk are two members of the Death Associated Protein Ser/Thr Kinase (DAP-kinase) family, which function in different settings of cell death including autophagy. DAP kinases are very similar in their catalytic domains but differ substantially in their extra-catalytic domains. This difference is crucial for the significantly different modes of regulation and function among DAP kinases. Here we report the identification of a novel alternatively spliced kinase isoform of the DRP-1 gene, termed DRP-1β. The alternative splicing event replaces the whole extra catalytic domain of DRP-1 with a single coding exon that is closely related to the sequence of the extra catalytic domain of ZIPk. As a consequence, DRP-1β lacks the calmodulin regulatory domain of DRP-1, and instead contains a leucine zipper-like motif similar to the protein binding region of ZIPk. Several functional assays proved that this new isoform retained the biochemical and cellular properties that are common to DRP-1 and ZIPk, including myosin light chain phosphorylation, and activation of membrane blebbing and autophagy. In addition, DRP-1β also acquired binding to the ATF4 transcription factor, a feature characteristic of ZIPk but not DRP-1. Thus, a splicing event of the DRP-1 produces a ZIPk like isoform. DRP-1β is highly conserved in evolution, present in all known vertebrate DRP-1 loci. We detected the corresponding mRNA and protein in embryonic mouse brains and in human embryonic stem cells thus confirming the in vivo utilization of this isoform. The discovery of module conservation within the DAPk family members illustrates a parsimonious way to increase the functional complexity within protein families. It also provides crucial data for modeling the expansion and evolution of DAP kinase proteins within vertebrates, suggesting that DRP-1 and ZIPk most likely evolved from their ancient ancestor gene DAPk by two gene duplication events that occurred close to the emergence of vertebrates

    Expression analysis of the TAB2 protein in adult mouse tissues

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    Background: The Interleukin-1 (IL-1) signaling component TAK1 binding protein 2 (TAB2) plays a role in activating the NFκB and JNK signaling pathways. Additionally, TAB2 functions in the nucleus as a repressor of NFκB-mediated gene regulation. Objective: To obtain insight into the function of TAB2 in the adult mouse, we analyzed the in vivo TAB2 expression pattern. Materials and methods: Cell lines and adult mouse tissues were analyzed for TAB2 protein expression and localization. Results: Immunohistochemical staining for TAB2 protein revealed expression in the vascular endothelium of most tissues, hematopoietic cells and brain cells. While TAB2 is localized in both the nucleus and the cytoplasm in cell lines, cytoplasmic localization predominates in hematopoietic tissues in vivo. Conclusions: The TAB2 expression pattern shows striking similarities with previously reported IL-1 receptor expression and NFκB activation patterns, suggesting that TAB2 in vivo is playing a role in these signaling pathways

    A region-based palliative care intervention trial using the mixed-method approach: Japan OPTIM study

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    <p>Abstract</p> <p>Background</p> <p>Disseminating palliative care is a critical task throughout the world. Several outcome studies explored the effects of regional palliative care programs on a variety of end-points, and some qualitative studies investigated the process of developing community palliative care networks. These studies provide important insights into the potential benefits of regional palliative care programs, but the clinical implications are still limited, because: 1) many interventions included fundamental changes in the structure of the health care system, and, thus, the results would not be applicable for many regions where structural changes are difficult or unfeasible; 2) patient-oriented outcomes were not measured or explored only in a small number of populations, and interpretation of the results from a patient's view is difficult; and 3) no studies adopted a mixed-method approach using both quantitative and qualitative methodologies to interpret the complex phenomenon from multidimensional perspectives.</p> <p>Methods/designs</p> <p>This is a mixed-method regional intervention trial, consisting of a pre-post outcome study and qualitative process studies. The primary aim of the pre-post outcome study is to evaluate the change in the number of home deaths, use of specialized palliative care services, patient-reported quality of palliative care, and family-reported quality of palliative care after regional palliative care intervention. The secondary aim is to explore the changes in a variety of outcomes, including patients' quality of life, pain intensity, family care burden, and physicians' and nurses' knowledge, difficulties, and self-perceived practice. Outcome measurements used in this study include the Care Evaluation Scale, Good Death Inventory, Brief pain Inventory, Caregiving Consequence Inventory, Sense of Security Scale, Palliative Care Knowledge test, Palliative Care Difficulties Scale, and Palliative Care Self-reported Practice Scale. Study populations are a nearly representative sample of advanced cancer patients, bereaved family members, physicians, and nurses in the region.</p> <p>Qualitative process studies consist of 3 studies with each aim: 1) to describe the process in developing regional palliative care in each local context, 2) to understand how and why the regional palliative care program led to changes in the region and to propose a model for shaping regional palliative care, and 3) to systemically collect the barriers of palliative care at a regional level and potential resolutions. The study methodology is a case descriptive study, a grounded theory approach based on interviews, and a content analysis based on systemically collected data, respectively.</p> <p>Discussion</p> <p>This study is, to our knowledge, one of the most comprehensive evaluations of a region-based palliative care intervention program. This study has 3 unique aspects: 1) it measures a wide range of outcomes, including quality of care and quality of life measures specifically designed for palliative care populations, whether patients died where they actually preferred, the changes in physicians and nurses at a regional level; 2) adopts qualitative studies along with quantitative evaluations; and 3) the intervention is without a fundamental change in health care systems. A comprehensive understanding of the findings in this study will contribute to a deeper insight into how to develop community palliative care.</p> <p>Trial Registration</p> <p>UMIN Clinical Trials Registry (UMIN-CTR), Japan, UMIN000001274.</p

    Factors linked to severe thrombocytopenia during antiviral therapy in patients with chronic hepatitis c and pretreatment low platelet counts

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    <p>Abstract</p> <p>Background</p> <p>Baseline low platelet count (< 150,000/μL) increases the risk of on-treatment severe thrombocytopenia (platelet count < 50,000/μL) in patients with chronic hepatitis C (CHC) undergoing antiviral therapy, which may interrupt treatment. The purpose of this study was to identify risk factors for severe thrombocytopenia during treatment for CHC in patients with baseline thrombocytopenia.</p> <p>Methods</p> <p>Medical records were reviewed for 125 patients with CHC treated with antiviral therapy according to the standard of care, with regular follow-up examinations. Early platelet decline was defined as platelet decrease during the first 2 weeks of therapy.</p> <p>Results</p> <p>Severe thrombocytopenia developed in 12.8% of patients with baseline thrombocytopenia, and predicted a higher therapeutic dropout rate. Multivariate analysis revealed baseline platelet count < 100,000/μL and rapid early platelet decline (> 30% decline in the first 2 weeks) were significantly associated with severe thrombocytopenia (<it>P </it>< 0.001 and 0.003, odds ratios, 179.22 and 45.74, respectively). In these patients, baseline PLT ≥ 100,000/μL and lack of rapid early platelet decline predicted absence of severe thrombocytopenia (negative predictive values were 95.1% and 96.6%, respectively). In contrast, baseline platelet count < 100,000/μL combined with rapid early platelet decline predicted severe thrombocytopenia (positive predictive value was 100%).</p> <p>Conclusions</p> <p>For patients with CHC on antiviral therapy, baseline platelet counts < 100,000/μL and rapid early platelet decline can identify patients at high risk of developing on-treatment severe thrombocytopenia.</p

    Dlk/ZIP kinase-induced apoptosis in human medulloblastoma cells: requirement of the mitochondrial apoptosis pathway

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    Dlk/ZIP kinase is a member of the Death Associated Protein (DAP) kinase family of pro-apoptotic serine/threonine kinases that have been implicated in regulation of apoptosis and tumour suppression. Expression of both Dlk/ZIP kinase and its interaction partner Par-4 is maintained in four medulloblastoma cell lines investigated, whereas three of seven neuroblastoma cell lines have lost expression of Par-4. Overexpression of a constitutively pro-apoptotic deletion mutant of Dlk/ZIP kinase induced significant apoptosis in D283 medulloblastoma cells. Cell death was characterized by apoptotic membrane blebbing, and a late stage during which the cells had ceased blebbing and were drastically shrunken or disrupted into apoptotic bodies. Over-expression of the anti-apoptotic Bcl-xL protein had no effect on Dlk/ZIP kinase-induced membrane blebbing, but potently inhibited Dlk/ZIP kinase-induced cytochrome c release and transition of cells to late stage apoptosis. Treatment with caspase inhibitors delayed, but did not prevent entry into late stage apoptosis. These results demonstrate that Dlk/ZIP kinase-triggered apoptosis involves the mitochondrial apoptosis pathway. However, cell death proceeded in the presence of caspase inhibitors, suggesting that Dlk/ZIP kinase is able to activate alternative cell death pathways. Alterations of signal transduction pathways leading to Dlk/ZIP kinase induced apoptosis or loss of expression of upstream activators could play important roles in tumour progression and metastasis of neural tumours. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Nuclear magnetic moment of the neutron-rich nucleus <math><mmultiscripts><mi mathvariant="normal">O</mi><mprescripts/><none/><mn>21</mn></mmultiscripts></math>

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    International audienceThe ground-state magnetic dipole moment of the neutron-rich O21 isotope has been measured via β-ray-detected nuclear magnetic resonance (β-NMR) spectroscopy by using a spin-polarized secondary beam of O21 produced from the Ne22 primary beam. From the present measurement, the g factor |gexp(Og.s.21)|=0.6036(14) has been determined. Based on the comparison of this value with Schmidt values, we unambiguously confirm the νd5/2 configuration with spin and parity assignments Iπ=5/2+ for the O21 ground state, suggested by previously reported studies. Consequently, the magnetic moment has been determined as μexp(Og.s.21)=(−)1.5090(35)μN. The obtained experimental magnetic moment is in good agreement with the predictions of the shell-model calculations using the USD, YSOX, and SDPF-M interactions as well as random phase approximation (RPA) calculations. This observation indicates that the O21 nucleus in its ground state does not manifest any anomalous structure and is not influenced by the proximity of the drip line

    Nuclear magnetic moment of the neutron-rich nucleus <math><mmultiscripts><mi mathvariant="normal">O</mi><mprescripts/><none/><mn>21</mn></mmultiscripts></math>

    No full text
    International audienceThe ground-state magnetic dipole moment of the neutron-rich O21 isotope has been measured via β-ray-detected nuclear magnetic resonance (β-NMR) spectroscopy by using a spin-polarized secondary beam of O21 produced from the Ne22 primary beam. From the present measurement, the g factor |gexp(Og.s.21)|=0.6036(14) has been determined. Based on the comparison of this value with Schmidt values, we unambiguously confirm the νd5/2 configuration with spin and parity assignments Iπ=5/2+ for the O21 ground state, suggested by previously reported studies. Consequently, the magnetic moment has been determined as μexp(Og.s.21)=(−)1.5090(35)μN. The obtained experimental magnetic moment is in good agreement with the predictions of the shell-model calculations using the USD, YSOX, and SDPF-M interactions as well as random phase approximation (RPA) calculations. This observation indicates that the O21 nucleus in its ground state does not manifest any anomalous structure and is not influenced by the proximity of the drip line
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