32 research outputs found

    Etno-muzeji na otvorenom i zaĆĄtita spomenika kulture

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    Formation of the death-inducing signaling complex (DISC) initiates extrinsic apoptosis. Caspase-8 and its regulator cFLIP control death signaling by binding to death-receptor-bound FADD. By elucidating the function of the caspase-8 homolog, caspase-10, we discover that caspase-10 negatively regulates caspase-8-mediated cell death. Significantly, we reveal that caspase-10 reduces DISC association and activation of caspase-8. Furthermore, we extend our co-operative/hierarchical binding model of caspase-8/cFLIP and show that caspase-10 does not compete with caspase-8 for binding to FADD. Utilizing caspase-8-knockout cells, we demonstrate that caspase-8 is required upstream of both cFLIP and caspase-10 and that DISC formation critically depends on the scaffold function of caspase-8. We establish that caspase-10 rewires DISC signaling to NF-ÎșB activation/cell survival and demonstrate that the catalytic activity of caspase-10, and caspase-8, is redundant in gene induction. Thus, our data are consistent with a model in which both caspase-10 and cFLIP coordinately regulate CD95L-mediated signaling for death or survival

    Inactivation of Effector Caspases through Nondegradative Polyubiquitylation

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    Ubiquitin-mediated inactivation of caspases has long been postulated to contribute to the regulation of apoptosis. However, detailed mechanisms and functional consequences of caspase ubiquitylation have not been demonstrated. Here we show that the Drosophila Inhibitor of Apoptosis 1, DIAP1, blocks effector caspases by targeting them for polyubiquitylation and nonproteasomal inactivation. We demonstrate that the conjugation of ubiquitin to drICE suppresses its catalytic potential in cleaving caspase substrates. Our data suggest that ubiquitin conjugation sterically interferes with substrate entry and reduces the caspase’s proteolytic velocity. Disruption of drICE ubiquitylation, either by mutation of DIAP1’s E3 activity or drICE’s ubiquitin-acceptor lysines, abrogates DIAP1’s ability to neutralize drICE and suppress apoptosis in vivo. We also show that DIAP1 rests in an “inactive” conformation that requires caspase-mediated cleavage to subsequently ubiquitylate caspases. Taken together, our findings demonstrate that effector caspases regulate their own inhibition through a negative feedback mechanism involving DIAP1 “activation” and nondegradative polyubiquitylation

    Discovery of naturally occurring ESR1 mutations in breast cancer cell lines modelling endocrine resistance.

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    Resistance to endocrine therapy remains a major clinical problem in breast cancer. Genetic studies highlight the potential role of estrogen receptor-α (ESR1) mutations, which show increased prevalence in the metastatic, endocrine-resistant setting. No naturally occurring ESR1 mutations have been reported in in vitro models of BC either before or after the acquisition of endocrine resistance making functional consequences difficult to study. We report the first discovery of naturally occurring ESR1 Y537C and ESR1 Y537S mutations in MCF7 and SUM44 ESR1-positive cell lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR). Mutations were enriched with time, impacted on ESR1 binding to the genome and altered the ESR1 interactome. The results highlight the importance and functional consequence of these mutations and provide an important resource for studying endocrine resistance.Cancer Research U

    Signal Integration by the IÎșB Protein Pickle Shapes <i>Drosophila</i> Innate Host Defense

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    SummaryPattern recognition receptors are activated following infection and trigger transcriptional programs important for host defense. Tight regulation of NF-ÎșB activation is critical to avoid detrimental and misbalanced responses. We describe Pickle, a Drosophila nuclear IÎșB that integrates signaling inputs from both the Imd and Toll pathways by skewing the transcriptional output of the NF-ÎșB dimer repertoire. Pickle interacts with the NF-ÎșB protein Relish and the histone deacetylase dHDAC1, selectively repressing Relish homodimers while leaving other NF-ÎșB dimer combinations unscathed. Pickle’s ability to selectively inhibit Relish homodimer activity contributes to proper host immunity and organismal health. Although loss of pickle results in hyper-induction of Relish target genes and improved host resistance to pathogenic bacteria in the short term, chronic inactivation of pickle causes loss of immune tolerance and shortened lifespan. Pickle therefore allows balanced immune responses that protect from pathogenic microbes while permitting the establishment of beneficial commensal host-microbe relationships

    The Developing Human Connectome Project Neonatal Data Release

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    The Developing Human Connectome Project has created a large open science resource which provides researchers with data for investigating typical and atypical brain development across the perinatal period. It has collected 1228 multimodal magnetic resonance imaging (MRI) brain datasets from 1173 fetal and/or neonatal participants, together with collateral demographic, clinical, family, neurocognitive and genomic data from 1173 participants, together with collateral demographic, clinical, family, neurocognitive and genomic data. All subjects were studied in utero and/or soon after birth on a single MRI scanner using specially developed scanning sequences which included novel motion-tolerant imaging methods. Imaging data are complemented by rich demographic, clinical, neurodevelopmental, and genomic information. The project is now releasing a large set of neonatal data; fetal data will be described and released separately. This release includes scans from 783 infants of whom: 583 were healthy infants born at term; as well as preterm infants; and infants at high risk of atypical neurocognitive development. Many infants were imaged more than once to provide longitudinal data, and the total number of datasets being released is 887. We now describe the dHCP image acquisition and processing protocols, summarize the available imaging and collateral data, and provide information on how the data can be accessed

    Prevalence of hepatitis C in the adult population of Bulgaria: a pilot study

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    Objective This study piloted a European technical protocol for conducting chronic hepatitis C prevalence surveys in the general population. The pilot study took place in the Bulgarian city of Stara Zagora in 2018, and results of setting up, conducting and evaluating the survey are presented. Results A probability-based sample of the general adult population was drawn from the local population registry, stratified by age and sex. A sample size of 999 was calculated, and accounting for 50% non-response, 1998 registered invitation letters were sent. Venous blood samples and questionnaire data were collected by the Regional Health Inspectorate in Stara Zagora. Blood samples were tested for anti-HCV, and if reactive for RNA. 252 (21.6%) of the participants were included in the study. Mean age and sex distribution differed between the participants (55.9 years, 60.3% females) and the total sample (48.9 years, 53.4%). The weighted chronic HCV prevalence among participants was 0.9% [95% CI 0.2–4.2%]. The approach of only sending registered letters contributed to a low response rate, and more efforts are needed to reduce non-response, especially among men and younger age groups. Results of the evaluation were integrated in the final technical protocol.Peer Reviewe
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