2,621 research outputs found

    A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer's Disease

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    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD) and accounts for 50-65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers' module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson's disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes, whereas AD in APOE ε4 non-carriers shares more common pathways with other types of diseases. The study reveals differential genetic bases and pathogenic and pathological processes between carriers and non-carriers, providing new insight into the mechanisms of the differences between APOE ε4 carriers and non-carriers in AD.published_or_final_versio

    Co-seismic ground deformation of Yushu Earthquake detected with D-InSAR technique

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    An earthquake of magnitude 7.1 suddenly occurred in Yushu county of Qinghai province on April 14, 2010. This paper presents the studies of using the data of Advanced Land Observing Satellite-Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR) before and after the earthquake to examine and calculate the co-seismic ground deformation. The differential SAR interferometry (D-InSAR) technique is used. The results show that the earthquake caused the ground deformation over a large area. The extension of the ground deformation followed the south-east to east direction and along the Yushu-Ganzi fault zone. The largest deformation was found about 350 mm at 33.7°N 96.81°E. It is along the line of sight (LOS) of SAR and can be detected with D-InSAR technique. The detected ground deformation was mainly uplifting. The detected ground deformation has an important value for evaluating the extent of ground damage and seismicity in Yushu after earthquake, inferring the nature of the quake faulting, and studying characteristics of seismic deformation. 2010-04-14青海玉树发生7.1级地震后, 作者利用震前和震后获取的日本ALOS卫星PALSAR遥感数据, 开展了差分干涉雷达(D-InSAR)地震同震形变测量与分析。结果表明: 玉树地震引起较大范围地表变形, 地震变形沿玉树—甘孜断裂带向南东东方向扩展, 在N33.7°, E96.81°附近达到最大形变量, D-InSAR监测到雷达视向上的最大形变量为35cm。地表形变特征对于评价玉树地震破坏程度、推断断层性质、研究地震形变和地震孕育特征具有重要的参考价值

    Lens epithelial cell apoptosis and intracellular Ca(2+) increase in the presence of xanthurenic acid

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    BACKGROUND: Xanthurenic acid is an endogenous product of tryptophan degradation by indoleamine 2,3-dioxygenase (IDO). We have previously reported that IDO is present in mammalian lenses, and xanthurenic acid is accumulated in the lenses with aging. Here, we studied the involvement of xanthurenic acid in the human lens epithelial cell physiology. METHODS: Human lens epithelial cells primary cultures were used. Control cells, and cells in the presence of xanthurenic acid grow in the dark. Western blot analysis and immunofluorescence studies were performed. RESULTS: In the presence of xanthurenic acid human lens epithelial cells undergo apoptosis-like cell death. In the control cells gelsolin stained the perinuclear region, whereas in the presence of 10 μM xanthurenic acid gelsolin is translocated to the cytoskeleton, but does not lead to cytoskeleton breakdown. In the same condition caspase-3 activation, and DNA fragmentation was observed. At low (5 to 10 μM) of xanthurenic acid concentration, the elongation of the cytoskeleton was associated with migration of mitochondria and cytochrome c release. At higher concentrations xanthurenic acid (20 μM and 40 μM) damaged mitochondria were observed in the perinuclear region, and nuclear DNA cleavage was observed. We observed an induction of calpain Lp 82 and an increase of free Ca(2+) in the cells in a xanthurenic acid concentration-dependent manner. CONCLUSIONS: The results show that xanthurenic acid accumulation in human lens epithelial cells disturbs the normal cell physiology and leads to a cascade of pathological events. Xanthurenic acid induces calpain Lp82 and caspases in the cells growing in the dark and can be involved in senile cataract development

    The micromorphology and histochemistry of foliar mixed indumentum of leucas lavandulaefolia (Lamiaceae)

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    Leucas lavandulaefolia Sm. (Lamiaceae) is an important medicinal plant with a broad spec-trum of pharmacological activities. This study aimed at characterizing the morphology, distribution, and chemical composition of the secretions of trichomes at different developmental stages on the leaves of L. lavandulaefolia, using light and electron microscopy. Morphological observations revealed the presence of bicellular non-glandular, glandular peltate, and capitate trichomes on both adaxial and abaxial leaf surfaces. The density of both non-glandular and glandular trichomes decreased with the progression of leaf development. Heads of peltate and short-stalked capitate trichomes were between 20.78–42.80 µm and 14.98–18.93 µm at different developmental stages. Furthermore, long-stalked capitate trichomes were rare and infrequent. Leaf sections revealed the presence of important secondary metabolites in glandular trichomes, i.e., terpenoids. This study represents the first report on the morphology and histochemistry of trichomes of L. lavandulaefolia; therefore, there is a great scope for further research in this field

    State based model of long-term potentiation and synaptic tagging and capture

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    Recent data indicate that plasticity protocols have not only synapse-specific but also more widespread effects. In particular, in synaptic tagging and capture (STC), tagged synapses can capture plasticity-related proteins, synthesized in response to strong stimulation of other synapses. This leads to long-lasting modification of only weakly stimulated synapses. Here we present a biophysical model of synaptic plasticity in the hippocampus that incorporates several key results from experiments on STC. The model specifies a set of physical states in which a synapse can exist, together with transition rates that are affected by high- and low-frequency stimulation protocols. In contrast to most standard plasticity models, the model exhibits both early- and late-phase LTP/D, de-potentiation, and STC. As such, it provides a useful starting point for further theoretical work on the role of STC in learning and memory

    Antagonism between ambient ozone increase and urbanization-oriented population migration on Chinese cardiopulmonary mortality

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    Ever-increasing ambient ozone (O3) pollution in China has been exacerbating cardiopulmonary premature deaths. However, the urban-rural exposure inequity has seldom been explored. Here, we assess population-scale O3 exposure and mortality burdens between 1990 and 2019 based on integrated pollution tracking and epidemiological evidence. We find Chinese population have been suffering from climbing O3 exposure by 4.3 ± 2.8 ppb per decade as a result of rapid urbanization and growing prosperity of socioeconomic activities. Rural residents are broadly exposed to 9.8 ± 4.1 ppb higher ambient O3 than the adjacent urban citizens, and thus urbanization-oriented migration compromises the exposure-associated mortality on total population. Cardiopulmonary excess premature deaths attributable to long-term O3 exposure, 373,500 (95% uncertainty interval [UI]: 240,600–510,900) in 2019, is underestimated in previous studies due to ignorance of cardiovascular causes. Future O3 pollution policy should focus more on rural population who are facing an aggravating threat of mortality risks to ameliorate environmental health injustice

    Structural evolution of GeMn/Ge superlattices grown by molecular beam epitaxy under different growth conditions

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    GeMn/Ge epitaxial 'superlattices' grown by molecular beam epitaxy with different growth conditions have been systematically investigated by transmission electron microscopy. It is revealed that periodic arrays of GeMn nanodots can be formed on Ge and GaAs substrates at low temperature (approximately 70°C) due to the matched lattice constants of Ge (5.656 Å) and GaAs (5.653 Å), while a periodic Ge/GeMn superlattice grown on Si showed disordered GeMn nanodots with a large amount of stacking faults, which can be explained by the fact that Ge and Si have a large lattice mismatch. Moreover, by varying growth conditions, the GeMn/Ge superlattices can be manipulated from having disordered GeMn nanodots to ordered coherent nanodots and then to ordered nanocolumns

    Coordinated optimization of visual cortical maps (II) Numerical studies

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    It is an attractive hypothesis that the spatial structure of visual cortical architecture can be explained by the coordinated optimization of multiple visual cortical maps representing orientation preference (OP), ocular dominance (OD), spatial frequency, or direction preference. In part (I) of this study we defined a class of analytically tractable coordinated optimization models and solved representative examples in which a spatially complex organization of the orientation preference map is induced by inter-map interactions. We found that attractor solutions near symmetry breaking threshold predict a highly ordered map layout and require a substantial OD bias for OP pinwheel stabilization. Here we examine in numerical simulations whether such models exhibit biologically more realistic spatially irregular solutions at a finite distance from threshold and when transients towards attractor states are considered. We also examine whether model behavior qualitatively changes when the spatial periodicities of the two maps are detuned and when considering more than 2 feature dimensions. Our numerical results support the view that neither minimal energy states nor intermediate transient states of our coordinated optimization models successfully explain the spatially irregular architecture of the visual cortex. We discuss several alternative scenarios and additional factors that may improve the agreement between model solutions and biological observations.Comment: 55 pages, 11 figures. arXiv admin note: substantial text overlap with arXiv:1102.335
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