26 research outputs found
Тенденції розвитку національної інноваційної системи в Україні
Проаналізовано національну інноваційну систему України. Розглянуто галузі промисловості України за ознаками інноваційної активності та досліджено темпи зростання показників, враховуючи індекс інфляції. Встановлено, що спад темпів зростання динаміки реалізованої продукції призводить до зменшення витрат на інноваційну діяльність.Дан анализ национальной инновационной системы Украины. Рассмотрены отрасли промышленности Украины по признакам инновационной активности и исследованы темпы роста показателей, учитывая индекс инфляции. Установлено, что спад темпов роста динамики реализованной продукции приводит к уменьшению затрат на инновационную деятельность.This article analyses national innovation system of Ukraine. Examined the industry of Ukraine based on innovative activity and investigated the growth indicators, taking into account inflation-index. It is established that the slowdown in the dynamics realized production leads to a decrease in the cost of innovation
Myosin V regulates synaptopodin clustering and localization in the dendrites of hippocampal neurons
The spine apparatus (SA) is an endoplasmic reticulum-related
organelle that is present in a subset of dendritic spines in cortical
and pyramidal neurons, and plays an important role in Ca2+
homeostasis and dendritic spine plasticity. The protein
synaptopodin is essential for the formation of the SA and is widely
used as a maker for this organelle. However, it is still unclear which
factors contribute to its localization at selected synapses, and how it
triggers local SA formation. In this study, we characterized
development, localization and mobility of synaptopodin clusters in
hippocampal primary neurons, as well as the molecular dynamics
within these clusters. Interestingly, synaptopodin at the shaftassociated clusters is less dynamic than at spinous clusters. We
identify the actin-based motor proteins myosin V (herein referring to
both the myosin Va and Vb forms) and VI as novel interaction partners
of synaptopodin, and demonstrate that myosin V is important for the
formation and/or maintenance of the SA. We found no evidence of
active microtubule-based transport of synaptopodin. Instead, new
clusters emerge inside spines, which we interpret as the SA being
assembled on-site
Caldendrin–Jacob: A Protein Liaison That Couples NMDA Receptor Signalling to the Nucleus
NMDA (N-methyl-D-aspartate) receptors and calcium can exert multiple and very divergent effects within neuronal cells, thereby impacting opposing occurrences such as synaptic plasticity and neuronal degeneration. The neuronal Ca2+ sensor Caldendrin is a postsynaptic density component with high similarity to calmodulin. Jacob, a recently identified Caldendrin binding partner, is a novel protein abundantly expressed in limbic brain and cerebral cortex. Strictly depending upon activation of NMDA-type glutamate receptors, Jacob is recruited to neuronal nuclei, resulting in a rapid stripping of synaptic contacts and in a drastically altered morphology of the dendritic tree. Jacob's nuclear trafficking from distal dendrites crucially requires the classical Importin pathway. Caldendrin binds to Jacob's nuclear localization signal in a Ca2+-dependent manner, thereby controlling Jacob's extranuclear localization by competing with the binding of Importin-α to Jacob's nuclear localization signal. This competition requires sustained synapto-dendritic Ca2+ levels, which presumably cannot be achieved by activation of extrasynaptic NMDA receptors, but are confined to Ca2+ microdomains such as postsynaptic spines. Extrasynaptic NMDA receptors, as opposed to their synaptic counterparts, trigger the cAMP response element-binding protein (CREB) shut-off pathway, and cell death. We found that nuclear knockdown of Jacob prevents CREB shut-off after extrasynaptic NMDA receptor activation, whereas its nuclear overexpression induces CREB shut-off without NMDA receptor stimulation. Importantly, nuclear knockdown of Jacob attenuates NMDA-induced loss of synaptic contacts, and neuronal degeneration. This defines a novel mechanism of synapse-to-nucleus communication via a synaptic Ca2+-sensor protein, which links the activity of NMDA receptors to nuclear signalling events involved in modelling synapto-dendritic input and NMDA receptor–induced cellular degeneration
Nuclear Translocation of Jacob in Hippocampal Neurons after Stimuli Inducing Long-Term Potentiation but Not Long-Term Depression
Background: In recent years a number of potential synapto-nuclear protein messengers have been characterized that are thought to be involved in plasticity-related gene expression, and that have the capacity of importin- mediated and activity-dependent nuclear import. However, there is a surprising paucity of data showing the nuclear import of such proteins in cellular models of learning and memory. Only recently it was found that the transcription factor cyclic AMP response element binding protein 2 (CREB2) transits to the nucleus during long-term depression (LTD), but not during long-term potentiation (LTP) of synaptic transmission in hippocampal primary neurons. Jacob is another messenger that couples NMDA-receptor-activity to nuclear gene expression. We therefore aimed to study whether Jacob accumulates in the nucleus in physiological relevant models of activity-dependent synaptic plasticity. Methodology/Principal Findings: We have analyzed the dynamics of Jacob’s nuclear import following induction of NMDA-receptor dependent LTP or LTD at Schaffer collateral-CA1 synapses in rat hippocampal slices. Using time-lapse imaging of neurons expressing a Jacob-Green-Fluorescent-Protein we found that Jacob rapidly translocates from dendrites to the nucleus already during the tetanization period of LTP, but not after induction of LTD. Immunocytochemical stainings confirmed the nuclear accumulation of endogenous Jacob in comparison to apical dendrites after induction of LTP but not LTD. Complementary findings were obtained after induction of NMDA-receptor dependent chemical LTP and LTD i
Diagnostic Difficulties of Mucopolysaccharidosis Type I Mild Forms: Clinical Cases
Mucopolysaccharidosis type I mild forms include Scheie syndrome and Hurler-Scheie syndrome that are characterized by slow progression, intact intelligence, and primarily effect on visual organ, musculoskeletal and cardiovascular systems. Early diagnostics, multidisciplinary approach to examination and monitoring, timely management are crucial in maintenance of patients' quality of life, preventing complications development and early disability. The article provides the overview of published data and description of 3 clinical cases with mild course of mucopolysaccharidosis type I
Probing cytoskeletal modulation of passive and active intracellular dynamics using nanobody-functionalized quantum dots
The cytoplasm is a highly complex and heterogeneous medium that is structured by the cytoskeleton. How local transport depends on the heterogeneous organization and dynamics of F-actin and microtubules is poorly understood. Here we use a novel delivery and functionalization strategy to utilize quantum dots (QDs) as probes for active and passive intracellular transport. Rapid imaging of non-functionalized QDs reveals two populations with a 100-fold difference in diffusion constant, with the faster fraction increasing upon actin depolymerization. When nanobody-functionalized QDs are targeted to different kinesin motor proteins, their trajectories do not display strong actin-induced transverse displacements, as suggested previously. Only kinesin-1 displays subtle directional fluctuations, because the subset of microtubules used by this motor undergoes prominent undulations. Using actin-targeting agents reveals that F-actin suppresses most microtubule shape remodelling, rather than promoting it. These results demonstrate how the spatial heterogeneity of the cytoskeleton imposes large variations in non-equilibrium intracellular dynamics
Efficient switching of mCherry fluorescence using chemical caging
Fluorophores with dynamic or controllable fluorescence emission have become essential tools for advanced imaging, such as superresolution imaging. These applications have driven the continuing development of photoactivatable or photoconvertible labels, including genetically encoded fluorescent proteins. These new probes work well but require the introduction of new labels that may interfere with the proper functioning of existing constructs and therefore require extensive functional characterization. In this work we show that the widely used red fluorescent protein mCherry can be brought to a purely chemically induced blue-fluorescent state by incubation with β-mercaptoethanol (βME). The molecules can be recovered to the red fluorescent state by washing out the βME or through irradiation with violet light, with up to 80% total recovery. We show that this can be used to perform single-molecule localization microscopy (SMLM) on cells expressing mCherry, which renders this approach applicable to a very wide range of existing constructs. We performed a detailed investigation of the mechanism underlying these dynamics, using X-ray crystallography, NMR spectroscopy, and ab initio quantum-mechanical calculations. We find that the βME-induced fluorescence quenching of mCherry occurs both via the direct addition of βME to the chromophore and through βME-mediated reduction of the chromophore. These results not only offer a strategy to expand SMLM imaging to a broad range of available biological models, but also present unique insights into the chemistry and functioning of a highly important class of fluorophores
Resolving bundled microtubules using anti-tubulin nanobodies
textabstractMicrotubules are hollow biopolymers of 25-nm diameter and are key constituents of the cytoskeleton. In neurons, microtubules are organized differently between axons and dendrites, but their precise organization in different compartments is not completely understood. Super-resolution microscopy techniques can detect specific structures at an increased resolution, but the narrow spacing between neuronal microtubules poses challenges because most existing labelling strategies increase the effective microtubule diameter by 20-40 nm and will thereby blend neighbouring microtubules into one structure. Here we develop single-chain antibody fragments (nanobodies) against tubulin to achieve super-resolution imaging of microtubules with a decreased apparent diameter. To test the resolving power of these novel probes, we generate microtubule bundles with a known spacing of 50-70 nm and successfully resolve individual microtubules. Individual bundled microtubules can also be resolved in different mammalian cells, including hippocampal neurons, allowing novel insights into fundamental mechanisms of microtubule organization in cell- and neurobiology