Search results for " Helix"
showing 10 items of 106 documents
Structure and function of the vacuolar Ccc1/VIT1 family of iron transporters and its regulation in fungi
2020
Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/V…
L'innovazione nelle aree rurali: l'ambiente e il modello della quintupla elica
2017
In this paper we analyze some specific conditions for local and regional development. Our interest is oriented towards a multidimensional aspect of peripheral and rural areas. The rural areas considered as a productive eco-system reflects a strong relationship between the agriculture and other economic activities, In addition eco-systems must be protected and enhanced to develop innovation models such as the Quadruple and Quintuple Helix, that propose roles and responsibilities for a new regional development trajectory. According to the Quintuple Helix Model and the implementation of the Smart Specialization Strategy, this paper underlines the importance of connecting the innovation process…
Measuring personal networks and their relationship with scientific production
2011
24 p., 2 figures, 5 tables, 1 appendix and references
Augstskolas un industrijas sadarbība studentu inovāciju veicināšanai: Latvijas Universitātes gadījuma izpēte
2017
Darbā tiek pētīta augstskolas un industrijas sadarbība inovāciju veicināšanai Eiropas Savienības inovāciju politikas kontekstā. Darba mērķis ir izpētīt augstskolas un industrijas sadarbības veidus, studentu iesaisti sadarbībā, kā arī šo sadarbību ietekmējošos faktorus Latvijas Universitātē. Tika konstatēts, ka Latvijas Universitātes sadarbības ar industriju un studentu iesaistes prakses ir dažādas, un tās atšķiras no fakultātes uz fakultāti. Studentu pētniecisko sadarbību ar industriju, kas ietver inovatīvu risinājumu izstrādi, veicina, galvenokārt, attiecīgās fakultātes mācībspēku sadarbība ar industriju, kā arī iespēja studentam par attiecīgo pētniecības tēmu izstrādāt noslēguma darbu. Pē…
Diagnostic strategy in segmentation defect of the vertebrae: a retrospective study of 73 patients
2018
BackgroundSegmentation defects of the vertebrae (SDV) are non-specific features found in various syndromes. The molecular bases of SDV are not fully elucidated due to the wide range of phenotypes and classification issues. The genes involved are in the Notch signalling pathway, which is a key system in somitogenesis. Here we report on mutations identified in a diagnosis cohort of SDV. We focused on spondylocostal dysostosis (SCD) and the phenotype of these patients in order to establish a diagnostic strategy when confronted with SDV.Patients and methodsWe used DNA samples from a cohort of 73 patients and performed targeted sequencing of the five known SCD-causing genes (DLL3,MESP2,LFNG,HES7…
Neurogenin 3+ cells contribute to β-cell neogenesis and proliferation in injured adult mouse pancreas
2013
Abstract: We previously showed that injury by partial duct ligation (PDL) in adult mouse pancreas activates Neurogenin 3 (Ngn3)(+) progenitor cells that can differentiate to beta cells ex vivo. Here we evaluate the role of Ngn3(+) cells in beta cell expansion in situ. PDL not only induced doubling of the beta cell volume but also increased the total number of islets. beta cells proliferated without extended delay (the so-called 'refractory' period), their proliferation potential was highest in small islets, and 86% of the beta cell expansion was attributable to proliferation of pre-existing beta cells. At sufficiently high Ngn3 expression level, upto 14% of all beta cells and 40% of small i…
FM19G11, a New Hypoxia-inducible Factor (HIF) Modulator, Affects Stem Cell Differentiation Status
2009
The biology of the alpha subunits of hypoxia-inducible factors (HIF alpha) has expanded from their role in angiogenesis to their current position in the self-renewal and differentiation of stem cells. The results reported in this article show the discovery of FM19G11, a novel chemical entity that inhibits HIF alpha proteins that repress target genes of the two alpha subunits, in various tumor cell lines as well as in adult and embryonic stem cell models from rodents and humans, respectively. FM19G11 inhibits at nanomolar range the transcriptional and protein expression of Oct4, Sox2, Nanog, and Tgf-alpha undifferentiating factors, in adult rat and human embryonic stem cells, FM19G11 activit…
Expression pattern of Notch1, 2 and 3 and Jagged1 and 2 in lymphoid and stromal thymus components: distinct ligand–receptor interactions in intrathym…
1999
The suggested role of Notch1 or its mutants in thymocyte differentiation and T cell tumorigenesis raises the question of how the different members of the Notch family influence distinct steps in T cell development and the role played by Notch ligands in the thymus. We report here that different Notch receptor-ligand partnerships may occur inside the thymus, as we observed differential expression of Notch1, 2 and 3 receptors, their ligands Jagged1 and 2, and downstream intracellular effectors hairy and Enhancer of Split homolog 1 (HES-1) and hairy and Enhancer of Split homolog 5 (HES-5), depending on ontogenetic stage and thymic cell populations. Indeed, while Jagged2 is expressed in both st…
Lysosomal Signaling Licenses Embryonic Stem Cell Differentiation via Inactivation of Tfe3
2019
International audience; Self-renewal and differentiation of pluripotent murine embryonic stem cells (ESCs) is regulated by extrinsic signaling pathways. It is less clear whether cellular metabolism instructs developmental progression. In an unbiased genome-wide CRISPR/Cas9 screen, we identified components of a conserved amino-acid-sensing pathway as critical drivers of ESC differentiation. Functional analysis revealed that lysosome activity, the Ragulator protein complex, and the tumor-suppressor protein Folliculin enable the Rag GTPases C and D to bind and seclude the bHLH transcription factor Tfe3 in the cytoplasm. In contrast, ectopic nuclear Tfe3 represses specific developmental and met…
HIF-1α and HIF-2α Are Differentially Regulated In vivo in Neuroblastoma: High HIF-1α Correlates Negatively to Advanced Clinical Stage and Tumor Vascu…
2009
Abstract Purpose: Hypoxia is considered to be a major driving force behind tumor angiogenesis. The stabilization and activation at hypoxia of the hypoxia-inducible factors HIF-1α and HIF-2α and the concomitant induction of expression of vascular endothelial growth factor (VEGF) and other proangiogenic factors provide a molecular frame for hypoxia-driven tumor angiogenesis. This study has investigated how HIF and VEGF protein levels relate to each other with regard to vascularization, tumor stage, and overall survival in neuroblastoma. Experimental Design: Tissue cores taken from tumor specimens representing 93 children with neuroblastoma were arranged on a microarray and stained for HIF-1α,…