120 research outputs found

    Interactions Between Aging and Alzheimer’s Disease on Structural Brain Networks

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    Normative aging and Alzheimer’s disease (AD) propagation alter anatomical connections among brain parcels. However, the interaction between the trajectories of age- and AD-linked alterations in the topology of the structural brain network is not well understood. In this study, diffusion-weighted magnetic resonance imaging (MRI) datasets of 139 subjects from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database were used to document their structural brain networks. The 139 participants consist of 45 normal controls (NCs), 37 with early mild cognitive impairment (EMCI), 27 with late mild cognitive impairment (LMCI), and 30 AD patients. All subjects were further divided into three subgroups based on their age (56–65, 66–75, and 71–85 years). After the structural connectivity networks were built using anatomically-constrained deterministic tractography, their global and nodal topological properties were estimated, including network efficiency, characteristic path length, transitivity, modularity coefficient, clustering coefficient, and betweenness. Statistical analyses were then performed on these metrics using linear regression, and one- and two-way ANOVA testing to examine group differences and interactions between aging and AD propagation. No significant interactions were found between aging and AD propagation in the global topological metrics (network efficiency, characteristic path length, transitivity, and modularity coefficient). However, nodal metrics (clustering coefficient and betweenness centrality) of some cortical parcels exhibited significant interactions between aging and AD propagation, with affected parcels including left superior temporal, right pars triangularis, and right precentral. The results collectively confirm the age-related deterioration of structural networks in MCI and AD patients, providing novel insight into the cross effects of aging and AD disorder on brain structural networks. Some early symptoms of AD may also be due to age-associated anatomic vulnerability interacting with early anatomic changes associated with AD

    OsLIC, a Novel CCCH-Type Zinc Finger Protein with Transcription Activation, Mediates Rice Architecture via Brassinosteroids Signaling

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    Rice architecture is an important agronomic trait and a major limiting factor for its high productivity. Here we describe a novel CCCH-type zinc finger gene, OsLIC (Oraza sativa leaf and tiller angle increased controller), which is involved in the regulation of rice plant architecture. OsLIC encoded an ancestral and unique CCCH type zinc finge protein. It has many orthologous in other organisms, ranging from yeast to humane. Suppression of endogenous OsLIC expression resulted in drastically increased leaf and tiller angles, shortened shoot height, and consequently reduced grain production in rice. OsLIC is predominantly expressed in rice collar and tiller bud. Genetic analysis suggested that OsLIC is epistatic to d2-1, whereas d61-1 is epistatic to OsLIC. Interestingly, sterols were significantly higher in level in transgenic shoots than in the wild type. Genome-wide expression analysis indicated that brassinosteroids (BRs) signal transduction was activated in transgenic lines. Moreover, transcription of OsLIC was induced by 24-epibrassinolide. OsLIC, with a single CCCH motif, displayed binding activity to double-stranded DNA and single-stranded polyrA, polyrU and polyrG but not polyrC. It contains a novel conserved EELR domain among eukaryotes and displays transcriptional activation activity in yeast. OsLIC may be a transcription activator to control rice plant architecture

    Fibroblast cell-based therapy prevents induction of alopecia areata in an experimental model

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    YesAlopecia areata (AA) is an autoimmune hair loss disease with infiltration of proinflammatory cells into hair follicles. Current therapeutic regimens are unsatisfactory mainly because of the potential for side effects and/or limited efficacy. Here we report that cultured, transduced fibroblasts, which express the immunomodulatory molecule indoleamine 2,3-dioxygenase (IDO), can be applied to prevent hair loss in an experimental AA model. A single intraperitoneal (IP) injection of IDO-expressing primary dermal fibroblasts was given to C3H/HeJ mice at the time of AA induction. While 60–70% of mice that received either control fibroblasts or vehicle injections developed extensive AA, none of the IDO-expressing fibroblast-treated mice showed new hair loss up to 20 weeks post injection. IDO cell therapy significantly reduced infiltration of CD4+ and CD8+ T cells into hair follicles and resulted in decreased expression of TNF-α, IFN-γ and IL-17 in the skin. Skin draining lymph nodes of IDO fibroblast-treated mice were significantly smaller, with more CD4+ CD25+ FoxP3+ regulatory T cells and fewer Th17 cells than those of control fibroblast and vehicle-injected mice. These findings indicate that IP injected IDO-expressing dermal fibroblasts can control inflammation and thereby prevent AA hair loss.Canadian Institutes of Health Researches (Funding Reference Number: 134214 and 136945)

    Design of PSO fuzzy Neural Network control for Ball and Plate system

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    The ball and plate system is a typical multi-variable plant, which is the extension of the traditional ball and beam problems. Particle swarm optimization algorithm fuzzy neural network control (PSO-FNNC) scheme is introduced for the ball and plate system. The fuzzy neural network (FNNC) is optimized by the offline particle swarm optimzation (PSO) of global searching ability and the online radius basis function (RBF) algorithm ability of local searching. Then, the optomized fuzzy RBF neural network (FRBF) tuned PID controller. The simulation results demonstrate the potential of the proposed technique, especially tracking speed, tracking accuracy and robustness is improved obviously, which embodies the nice characters of the PSO-FNNC scheme

    Roles of ubiquitination-mediated protein degradation in plant responses to abiotic stresses

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    Ubiquitination is a major modifier of signaling in all eukaryotes that results in the conjugation of ubiquitin to the lysine residues of acceptor proteins. The targeted protein is then subjected to degradation by the 26S proteasome, the major protein degradation system in eukaryotes. The ubiquitin-proteasome system (UPS) greatly influences plant growth and development by modulating the activity, localization, and stability of proteins. Plants are frequently exposed to various abiotic stresses during their life cycles; they rely on proteomic plasticity achieved by the UPS to adapt to unfavorable environmental conditions. In stress signal pathways, a large number of components are modified by specific ubiquitination machinery. In this review, we highlight recent advances in understanding the roles of ubiquitination in plant responses to abiotic stresses, including salt and drought, temperature, ultraviolet (UV), and nutrient availability. The review focuses primarily on the roles of the UPS. In salt and/or drought stress signaling, a number of E3 ligases mediate the stress response in both abscisic acid (ABA)-dependent and ABA-independant pathways. The UPS-mediated regulation of several key ABA-regulated transcriptional factors, e.g. ABI3 and ABI5, has been well documented. In cold signaling, the transcription factor ICE1 is targeted by E3 ligase HOSI for proteosomal degradation. Under UV stress, CUL4-DDB1A-DDB2 E3 ligase participates in DNA excision repair, and COP1 interacts with the UVR8 mediated UV response. The UPS is also involved in the uptake, transport, and homeostasis of nutrients such as iron, phosphorus, and nitrogen. SIZ1-mediated sumoylation, a ubiquitin-like modification, is necessary for a number of processes involved in plant responses to abiotic stresses. A challenge moving forward for researchers is to define more UPS components and to characterize their functions in plant responses to stress conditions; there is particular interest in identifying the ubiquitination targets that function in specific stress signaling pathways. (C) 2014 Elsevier B.V. All rights reserved

    A receptor-like protein RMC is involved in regulation of iron acquisition in rice

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    Iron (Fe) is one of the essential mineral elements for plant growth and development. Acquisition of Fe by plants is mediated by a complex network involving Fe mobilization, uptake by root cells, and transport within plants. Here, we evaluated the role of a previously clarified gene encoding a receptor-like protein from rice, OsRMC, in the regulation of Fe acquisition by comparing Fe concentration, biomass, and expression patterns of genes associated with Fe mobilization and transport in wild-type (WT) rice with those in OsRMC overexpression and RNA interference (RNAi) knockdown transgenic rice plants. Expression of OsRMC was upregulated in both shoots and roots upon exposure of WT to Fe-deficient medium. Expression levels of OsRMC were positively correlated with Fe concentration in rice plants under both Fe-sufficient and Fe-deficient conditions such that overexpression and RNAi lines had higher and lower Fe concentration in both roots and shoots than WT plants, respectively. Moreover, overexpression of OsRMC conferred greater accumulation of Fe in mature seeds under Fe-sufficient conditions. OsRMC may also play a role in regulation of Fe deficiency-induced changes in root growth, as evidenced by greater and smaller root systems of OsRMC overexpression lines and RNAi lines than WT under Fe-deficient conditions, respectively. Several Fe deficiency-responsive genes including OsDMAS1, OsNAS1, OsNAS2, OsNAAT1, OsIRT1, OsYSL15, and OsIRO2 were up- and downregulated in OsRMC-overexpressing and RNAi plants compared with WT rice plants. These novel findings highlight an important role of OsRMC played in mediation of Fe acquisition and root growth in rice, particularly under Fe-deficient conditions
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