44 research outputs found
ITR/IM: Enabling the Creation and Use of GeoGrids for Next Generation Geospatial Information
The objective of this project is to advance science in information management, focusing in particular on geospatial information. It addresses the development of concepts, algorithms, and system architectures to enable users on a grid to query, analyze, and contribute to multivariate, quality-aware geospatial information. The approach consists of three complementary research areas: (1) establishing a statistical framework for assessing geospatial data quality; (2) developing uncertainty-based query processing capabilities; and (3) supporting the development of space- and accuracy-aware adaptive systems for geospatial datasets. The results of this project will support the extension of the concept of the computational grid to facilitate ubiquitous access, interaction, and contributions of quality-aware next generation geospatial information. By developing novel query processes as well as quality and similarity metrics the project aims to enable the integration and use of large collections of disperse information of varying quality and accuracy. This supports the evolution of a novel geocomputational paradigm, moving away from current standards-driven approaches to an inclusive, adaptive system, with example potential applications in mobile computing, bioinformatics, and geographic information systems. This experimental research is linked to educational activities in three different academic programs among the three participating sites. The outreach activities of this project include collaboration with U.S. federal agencies involved in geospatial data collection, an international partner (Brazil\u27s National Institute for Space Research), and the organization of a 2-day workshop with the participation of U.S. and international experts
Pediatric malignancies presenting as a possible infectious disease
<p>Abstract</p> <p>Background</p> <p>The clinical, laboratory, and radiological features of malignancy can overlap with those of infection. The purpose of this study was to determine the findings in children who were initially thought to have an infectious disease but ultimately proved to have a malignancy.</p> <p>Methods</p> <p>The database of patients diagnosed with a malignancy in the Northern Alberta Children's Cancer Program (NACCP) January 1, 1993 to December 31, 2003 was merged with the database of inpatients referred to the infectious diseases service at the Stollery Children's Hospital and charts were reviewed on all patients referred to the infectious diseases consult service prior to the diagnosis of malignancy.</p> <p>Results</p> <p>An infectious diseases consultation for diagnosis was requested in 21 of 561 patients prior to the confirmation of malignancy, and 3 of these 21 patients had both infection and malignancy (leukemia (N = 13), lymphoma (N = 3), rhabdomyosarcoma (N = 1), Langerhan's cell histiocytosis (N = 1), fibrous histicocytosis (N = 1), ependymoma (N = 1), and neuroblastoma (N = 1). The most common reason for infectious diseases consultation was suspected muskuloskeletal infection (N = 9). A palpable or radiographically enlarged spleen was noted in 11 patients (52%). All but 2 patients had abnormal hematologic parameters while an elevated lactate dehydrogenase (LDH) occurred in 10 patients (48%). Delay of diagnosis because of investigation or therapy for an infectious disease occurred in only 2 patients.</p> <p>Conclusion</p> <p>It is not common for treatment of pediatric malignancies to be delayed because infection is thought to be the primary diagnosis. However, pediatric infectious diseases physicians should consider malignancy in the differential diagnosis when they see patients with fever and bone pain, unexplained splenomegaly or abnormal complete blood cell counts. Other clues may include hepatomegaly or elevated LDH.</p
eIF5A Promotes Translation Elongation, Polysome Disassembly and Stress Granule Assembly
Stress granules (SGs) are cytoplasmic foci at which untranslated mRNAs accumulate in cells exposed to environmental stress. We have identified ornithine decarboxylase (ODC), an enzyme required for polyamine synthesis, and eIF5A, a polyamine (hypusine)-modified translation factor, as proteins required for arsenite-induced SG assembly. Knockdown of deoxyhypusine synthase (DHS) or treatment with a deoxyhypusine synthase inhibitor (GC7) prevents hypusine modification of eIF5A as well as arsenite-induced polysome disassembly and stress granule assembly. Time-course analysis reveals that this is due to a slowing of stress-induced ribosome run-off in cells lacking hypusine-eIF5A. Whereas eIF5A only marginally affects protein synthesis under normal conditions, it is required for the rapid onset of stress-induced translational repression. Our results reveal that hypusine-eIF5A-facilitated translation elongation promotes arsenite-induced polysome disassembly and stress granule assembly in cells subjected to adverse environmental conditions
Characterization of MTAP gene expression in breast cancer patients and cell lines
MTAP is a ubiquitously expressed gene important for adenine and methionine salvage. The gene is located at 9p21, a chromosome region often deleted in breast carcinomas, similar to CDKN2A, a recognized tumor suppressor gene. Several research groups have shown that MTAP acts as a tumor suppressor, and some therapeutic approaches were proposed based on a tumors\ub4 MTAP status. We analyzed MTAP and CDKN2A gene (RT-qPCR) and protein (western-blotting) expression in seven breast cancer cell lines and evaluated their promoter methylation patterns to better characterize the contribution of these genes to breast cancer. Cytotoxicity assays with inhibitors of de novo adenine synthesis (5-FU, AZA and MTX) after MTAP gene knockdown showed an increased sensitivity, mainly to 5-FU. MTAP expression was also evaluated in two groups of samples from breast cancer patients, fresh tumors and paired normal breast tissue, and from formalin-fixed paraffin embedded (FFPE) core breast cancer samples diagnosed as Luminal-A tumors and triple negative breast tumors (TNBC). The difference of MTAP expression between fresh tumors and normal tissues was not statistically significant. However, MTAP expression was significantly higher in Luminal-A breast tumors than in TNBC, suggesting the lack of expression in more aggressive breast tumors and the possibility of using the new approaches based on MTAP status in TNB
Depletion of stromal cells expressing fibroblast activation protein-α from skeletal muscle and bone marrow results in cachexia and anemia.
Fibroblast activation protein-α (FAP) identifies stromal cells of mesenchymal origin in human cancers and chronic inflammatory lesions. In mouse models of cancer, they have been shown to be immune suppressive, but studies of their occurrence and function in normal tissues have been limited. With a transgenic mouse line permitting the bioluminescent imaging of FAP(+) cells, we find that they reside in most tissues of the adult mouse. FAP(+) cells from three sites, skeletal muscle, adipose tissue, and pancreas, have highly similar transcriptomes, suggesting a shared lineage. FAP(+) cells of skeletal muscle are the major local source of follistatin, and in bone marrow they express Cxcl12 and KitL. Experimental ablation of these cells causes loss of muscle mass and a reduction of B-lymphopoiesis and erythropoiesis, revealing their essential functions in maintaining normal muscle mass and hematopoiesis, respectively. Remarkably, these cells are altered at these sites in transplantable and spontaneous mouse models of cancer-induced cachexia and anemia. Thus, the FAP(+) stromal cell may have roles in two adverse consequences of cancer: their acquisition by tumors may cause failure of immunosurveillance, and their alteration in normal tissues contributes to the paraneoplastic syndromes of cachexia and anemia
Genome-wide identification of FoxO-dependent gene networks in skeletal muscle during C26 cancer cachexia
BACKGROUND: Evidence from cachectic cancer patients and animal models of cancer cachexia supports the involvement of Forkhead box O (FoxO) transcription factors in driving cancer-induced skeletal muscle wasting. However, the genome-wide gene networks and associated biological processes regulated by FoxO during cancer cachexia are unknown. We hypothesize that FoxO is a central upstream regulator of diverse gene networks in skeletal muscle during cancer that may act coordinately to promote the wasting phenotype. METHODS: To inhibit endogenous FoxO DNA-binding, we transduced limb and diaphragm muscles of mice with AAV9 containing the cDNA for a dominant negative (d.n.) FoxO protein (or GFP control). The d.n.FoxO construct consists of only the FoxO3a DNA-binding domain that is highly homologous to that of FoxO1 and FoxO4, and which outcompetes and blocks endogenous FoxO DNA binding. Mice were subsequently inoculated with Colon-26 (C26) cells and muscles harvested 26 days later. RESULTS: Blocking FoxO prevented C26-induced muscle fiber atrophy of both locomotor muscles and the diaphragm and significantly spared force deficits. This sparing of muscle size and function was associated with the differential regulation of 543 transcripts (out of 2,093) which changed in response to C26. Bioinformatics analysis of upregulated gene transcripts that required FoxO revealed enrichment of the proteasome, AP-1 and IL-6 pathways, and included several atrophy-related transcription factors, including Stat3, Fos, and Cebpb. FoxO was also necessary for the cancer-induced downregulation of several gene transcripts that were enriched for extracellular matrix and sarcomere protein-encoding genes. We validated these findings in limb muscles and the diaphragm through qRT-PCR, and further demonstrate that FoxO1 and/or FoxO3a are sufficient to increase Stat3, Fos, Cebpb, and the C/EBPβ target gene, Ubr2. Analysis of the Cebpb proximal promoter revealed two bona fide FoxO binding elements, which we further establish are necessary for Cebpb promoter activation in response to IL-6, a predominant cytokine in the C26 cancer model. CONCLUSIONS: These findings provide new evidence that FoxO-dependent transcription is a central node controlling diverse gene networks in skeletal muscle during cancer cachexia, and identifies novel candidate genes and networks for further investigation as causative factors in cancer-induced wasting.R01 AR060217 - NIAMS NIH HHS; R01 AR060209 - NIAMS NIH HHS; T32 HD043730 - NICHD NIH HHS; R00 HL098453 - NHLBI NIH HHS; R00HL098453 - NHLBI NIH HHS; R01AR060209 - NIAMS NIH HHS; R01AR060217 - NIAMS NIH HH
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RNA-Dependent Control of Histone Gene Expression by the Spinal Muscular Atrophy Protein SMN: Mechanisms and Role in Motor Neuron Disease
Ribonucleoproteins (RNPs) are RNA-protein complexes that carry out a variety of key cellular functions and are essential for the regulation of gene expression. Small nuclear RNPs (snRNPs) are a class of RNPs that regulate gene expression at the level of RNA processing in the nucleus. These RNPs are subject to complex and highly regulated biogenesis pathways in order to ensure sufficient snRNP levels are present within the cell. snRNPs are required for viability of all eukaryotic cells and the importance of proper snRNP function in vivo is further highlighted by the fact that the fatal motor neuron disease spinal muscular atrophy (SMA) is caused by a genetic deficiency in the ubiquitously expressed survival motor neuron (SMN) protein, an essential component of the snRNP biogenesis machinery. The most well characterized targets of SMN for RNP assembly are the spliceosomal snRNPs, which are critical factors that carry out pre-mRNA splicing. However, SMN is not believed to be solely dedicated to spliceosomal snRNP biogenesis but rather is thought to be a general RNP assembly machine. Yet, no other RNP targets of the SMN complex had previously been characterized in a conclusive manner. Understanding the cellular targets of SMN-mediated RNP assembly is critical for elucidating basic mechanisms of RNA regulation. Furthermore, despite increased understanding of the molecular function of SMN in spliceosomal snRNP biogenesis and the cellular basis of SMA in animal models, the molecular mechanisms through which loss of SMN function leads to motor neuron disease remain poorly defined. Thus, identifying additional RNP pathways that are dependent on SMN is key to uncover the molecular mechanisms of SMA and may also help in the design of novel therapeutic approaches to this devastating childhood disorder that is currently untreatable.
In an effort to expand on the established RNP targets of SMN for assembly, in this dissertation I explore the hypothesis that SMN is required for the biogenesis and function of U7 snRNP and that disruption of this pathway induced by SMN deficiency contributes to motor neuron pathology in SMA. While structurally analogous to spliceosomal snRNPs, U7 snRNP functions not in splicing but rather in the unique 3’-end processing mechanism of replication-dependent histone mRNAs. Here, I first provide detailed molecular characterization of the in vivo functional requirement of SMN for U7 snRNP biogenesis as well as histone mRNA 3’-end processing and proper histone gene expression. I go on to demonstrate that in a mouse model of SMA U7 snRNP biogenesis and function are severely impaired by SMN deficiency and these defects occur in disease-relevant SMA motor neurons. I then describe the development of a novel molecular strategy to restore U7 snRNP activity in a setting of SMN deficiency in order to investigate the functional consequences of U7 dysfunction in SMA. Finally, I apply this U7 restoration strategy to a mouse model of SMA using AAV9-mediated gene delivery and establish that disrupted U7 activity contributes to select aspects of motor neuron dysfunction in SMA mice.
Collectively, my dissertation work provides a significant expansion in our understanding of RNP pathways controlled by SMN and, for the first time, establishes the contribution of an SMN-dependent RNA pathway to SMA pathology in a mouse model of the disease that best recapitulates the human condition both genetically and phenotypically. The continuation of this work in the future not only may lead to a detailed molecular understanding of the mechanisms of SMA but possibly also to the development of novel therapeutic approaches for this deadly disease that are complementary to SMN upregulation
The impact of eSports and online video gaming on lifestyle behaviours in youth: A systematic review
Background: ESports has evolved into a hyper-competitive genre of video gaming. Emerging evidence has linked its intense engagement with mental health problems, with implications on youth development. We aim to summarise the impact of eSports and online video gaming on lifestyle outcomes. Method: We conducted a systematic review and meta-analysis of studies in journals published in the English language since 2011. We searched PubMed, Web of Science (WoS) and Bielefeld Academic Search Engine (BASE) using search strings related to eSports or video-gaming and lifestyle behaviours. Results: We identified 3694 studies, 36 of which met the inclusion criteria. The studies reported associations between online video gaming (including eSports participation and consumption) and poor lifestyle outcomes:physical activity-related (decreased levels of physical activity, increased body mass index (BMI) and sedentary behaviour)nutrition-related (poorer diet, sweetened beverage consumption) and sleep-related outcomes (decreased quality/duration, increased sleepiness/sleep deprivation). One study investigated physical lifestyle-related outcomes (eye strain, wrist pain, neck pain) Results indicate a widening breadth of research investigating associations between lifestyle outcomes and online video gaming. Conclusion: Lifestyle outcomes associated with engagement in eSports and video gaming are important to consider. This emphasizes the need for longitudinal studies which examine characteristics of gaming that may increase young people's risk of practicing unhealthy lifestyle behaviours. The accessibility of eSports to a wide digital audience highlights the need for this sector to promote healthy lifestyle behaviours among consumers and gamers.</p
A cell system for phenotypic screening of modifiers of SMN2 gene expression and function.
Spinal muscular atrophy (SMA) is an inherited neurodegenerative disease caused by homozygous inactivation of the SMN1 gene and reduced levels of the survival motor neuron (SMN) protein. Since higher copy numbers of the nearly identical SMN2 gene reduce disease severity, to date most efforts to develop a therapy for SMA have focused on enhancing SMN expression. Identification of alternative therapeutic approaches has partly been hindered by limited knowledge of potential targets and the lack of cell-based screening assays that serve as readouts of SMN function. Here, we established a cell system in which proliferation of cultured mouse fibroblasts is dependent on functional SMN produced from the SMN2 gene. To do so, we introduced the entire human SMN2 gene into NIH3T3 cell lines in which regulated knockdown of endogenous mouse Smn severely decreases cell proliferation. We found that low SMN2 copy number has modest effects on the cell proliferation phenotype induced by Smn depletion, while high SMN2 copy number is strongly protective. Additionally, cell proliferation correlates with the level of SMN activity in small nuclear ribonucleoprotein assembly. Following miniaturization into a high-throughput format, our cell-based phenotypic assay accurately measures the beneficial effects of both pharmacological and genetic treatments leading to SMN upregulation. This cell model provides a novel platform for phenotypic screening of modifiers of SMN2 gene expression and function that act through multiple mechanisms, and a powerful new tool for studies of SMN biology and SMA therapeutic development