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排序方式: 共有832条查询结果,搜索用时 812 毫秒
131.
Sabrina Florent-Béchard Cédric Desbène Pierre Garcia Ahmad Allouche Ihsen Youssef Marie-Christine Escanyé Violette Koziel Marine Hanse Catherine Malaplate-Armand Christophe Stenger Badreddine Kriem Frances T. Yen-Potin Jean Luc Olivier Thierry Pillot Thierry Oster 《Biochimie》2009
In the absence of efficient diagnostic and therapeutic tools, Alzheimer's disease (AD) is a major public health concern due to longer life expectancy in the Western countries. Although the precise cause of AD is still unknown, soluble β-amyloid (Aβ) oligomers are considered the proximate effectors of the synaptic injury and neuronal death occurring in the early stages of AD. Aβ oligomers may directly interact with the synaptic membrane, leading to impairment of synaptic functions and subsequent signalling pathways triggering neurodegeneration. Therefore, membrane structure and lipid status should be considered determinant factors in Aβ-oligomer-induced synaptic and cell injuries, and therefore AD progression. Numerous epidemiological studies have highlighted close relationships between AD incidence and dietary patterns. Among the nutritional factors involved, lipids significantly influence AD pathogenesis. It is likely that maintenance of adequate membrane lipid content could prevent the production of Aβ peptide as well as its deleterious effects upon its interaction with synaptic membrane, thereby protecting neurons from Aβ-induced neurodegeneration. As major constituents of neuronal lipids, n-3 polyunsaturated fatty acids are of particular interest in the prevention of AD valuable diet ingredients whose neuroprotective properties could be essential for designing preventive nutrition-based strategies. In this review, we discuss the functional relevance of neuronal membrane features with respect to susceptibility to Aβ oligomers and AD pathogenesis, as well as the prospective capacities of lipids to prevent or to delay the disease. 相似文献
132.
Isabelle Brigaud Xavier Grosmaître Marie-Christine François Emmanuelle Jacquin-Joly 《Cell and tissue research》2009,335(2):455-463
In insects, biogenic amines have been shown to play an important role in olfactory plasticity. In a first attempt to decipher the underlying molecular mechanisms, we report the molecular cloning and precise expression pattern of a newly identified octopamine/tyramine-receptor-encoding gene in the antennae of the noctuid moth Mamestra brassicae (MbraOAR/TAR). A full-length cDNA has been obtained through homology cloning in combination with rapid amplification of cDNA ends/polymerase chain reaction; the deduced protein exhibits high identities with previously identified octopamine/tyramine receptors in other moths. In situ hybridization within the antennae has revealed that MbraOAR/TAR is expressed at the bases of both pheromone-sensitive and non-sensitive olfactory sensilla and in cells with a neurone-like shape. In accordance with previous physiological studies that have revealed a role of biogenic amines in the electrical activity of the receptor neurones, our results suggest that biogenic amines (either octopamine or tyramine) target olfactory receptor neurones to modulate olfactory coding as early as the antennal level. 相似文献
133.
Thomas Lefebvre Bruno J. Gonzalez†‡ David Vaudry Laurence Desrues Antony Falluel-Morel Nicolas Aubert§ Alain Fournier¶ Marie-Christine Tonon Hubert Vaudry Hélène Castel 《Journal of neurochemistry》2009,110(3):976-989
Transient exposure to ethanol (EtOH) results in a massive neurodegeneration in the developing brain leading to behavioral and cognitive deficits observed in fetal alcohol syndrome. There is now compelling evidence that K+ channels play an important role in the control of programmed cell death. The aim of the present work was to investigate the involvement of K+ channels in the EtOH-induced cerebellar granule cell death and/or survival. At low and high concentrations, EtOH evoked membrane depolarization and hyperpolarization, respectively. Bath perfusion of EtOH (10 mM) depressed the I A (transient K+ current) potassium current whereas EtOH (400 mM) provoked a marked potentiation of the specific I K (delayed rectifier K+ current) current. Pipette dialysis with GTPγS or GDPβS did not modify the effects of EtOH (400 mM) on both membrane potential and I K current. In contrast, the reversible depolarization and slowly recovering inhibition of I A induced by EtOH (10 mM) became irreversible in the presence of GTPγS. EtOH (400 mM) induced prodeath responses whereas EtOH (10 mM) and K+ channel blockers promoted cell survival. Altogether, these results indicate that in cerebellar granule cells, EtOH mediates a dual effect on K+ currents partly involved in the control of granule cell death. 相似文献
134.
Cláudia Santos Gai Paulo Teixeira Lacava Maria Carolina Quecine Marie-Christine Auriac João Roberto Spotti Lopes Welington Luiz Araújo Thomas Albert Miller João Lúcio Azevedo 《Journal of microbiology (Seoul, Korea)》2009,47(4):448-454
Methylobacterium mesophilicum, originally isolated as an endophytic bacterium from citrus plants, was genetically transformed to express green fluorescent
protein (GFP). The GFP-labeled strain of M. mesophilicum was inoculated into Catharanthus roseus (model plant) seedlings and further observed colonizing its xylem vessels. The transmission of this endophyte by Bucephalogonia xanthophis, one of the insect vectors that transmit Xylella fastidiosa subsp. pauca, was verified by insects feeding from fluids containing the GFP bacterium followed by transmission to plants and isolating
the endophyte from C. roseus plants. Forty-five days after inoculation, the plants exhibited endophytic colonization by M. mesophilicum, confirming this bacterium as a nonpathogenic, xylem-associated endophyte. Our data demonstrate that M. mesophilicum not only occupy the same niche of X. fastidiosa subsp. pauca inside plants but also may be transmitted by B. xanthophis. The transmission, colonization, and genetic manipulation of M. mesophilicum is a prerequisite to examining the potential use of symbiotic control to interrupt the transmission of X. fastidiosa subsp. pauca, the bacterial pathogen causing Citrus variegated chlorosis by insect vectors. 相似文献
135.
Aurélia Boulaflous Claude Saint-Jore-Dupas Marie-Carmen Herranz-Gordo Sophie Pagny-Salehabadi Carole Plasson Frédéric Garidou Marie-Christine Kiefer-Meyer Christophe Ritzenthaler Lo?c Faye Véronique Gomord 《BMC plant biology》2009,9(1):144
Background
In eukaryotic cells, the membrane compartments that constitute the exocytic pathway are traversed by a constant flow of lipids and proteins. This is particularly true for the endoplasmic reticulum (ER), the main "gateway of the secretory pathway", where biosynthesis of sterols, lipids, membrane-bound and soluble proteins, and glycoproteins occurs. Maintenance of the resident proteins in this compartment implies they have to be distinguished from the secretory cargo. To this end, they must possess specific ER localization determinants to prevent their exit from the ER, and/or to interact with receptors responsible for their retrieval from the Golgi apparatus. Very few information is available about the signal(s) involved in the retention of membrane type II protein in the ER but it is generally accepted that sorting of ER type II cargo membrane proteins depends on motifs mainly located in their cytosolic tails. 相似文献136.
Roussel A Lescar J Vaney MC Wengler G Wengler G Rey FA 《Structure (London, England : 1993)》2006,14(1):75-86
Semliki Forest virus (SFV) is enveloped by a lipid bilayer enclosed within a glycoprotein cage made by glycoproteins E1 and E2. E1 is responsible for inducing membrane fusion, triggered by exposure to the acidic environment of the endosomes. Acidic pH induces E1/E2 dissociation, allowing E1 to interact with the target membrane, and, at the same time, to rearrange into E1 homotrimers that drive the membrane fusion reaction. We previously reported a preliminary Calpha trace of the monomeric E1 glycoprotein ectodomain and its organization on the virus particle. We also reported the 3.3 A structure of the trimeric, fusogenic conformation of E1. Here, we report the crystal structure of monomeric E1 refined to 3 A resolution and describe the amino acids involved in contacts in the virion. These results identify the major determinants for the E1/E2 icosahedral shell formation and open the way to rational mutagenesis approaches to shed light on SFV assembly. 相似文献
137.
Epstein-Barr virus (EBV) genome and expression in breast cancer tissue: effect of EBV infection of breast cancer cells on resistance to paclitaxel (Taxol) 下载免费PDF全文
138.
Nawel Selami Marie-Christine Auriac Olivier Catrice Delphine Capela Meriem Kaid-Harche Ton Timmers 《Plant and Soil》2014,374(1-2):109-119
Background and aims
In spite of the importance of Retama species for dune stabilization and re-vegetation and the contribution to the bio-fertilization of semi-arid and arid ecosystems, the symbiotic interaction of Retama species with rhizobia remains largely unstudied. In this paper, we aim to provide the first detailed study on nodule morphology and anatomy of Retama monosperma.Methods
We collected nodules from coastal areas nearby Oran (Algeria) and studied in detail their anatomy and ultrastructure by light and electron microscopy.Results
First, we confirmed the likely identity of the microsymbiont as B. retamae and found that nodules of R. monosperma belong to the genistoid type of indeterminate nodules. Infection threads, typical for most nodules of legumes, are absent in nodules of R. monosperma and bacterial spread is associated with plant cell division. The nitrogen fixation zone is homogenous with only invaded cells and a network of non-invaded cells found in many nodules, is absent. Moreover, endoreduplication does not take place in bacteroids in nodules of R. monosperma.Conclusions
The features observed in this study are compared to the morphology and anatomy of nodules of other legumes and the possible consequences for nodule functioning and the mode of infection during the establishment of the interaction are discussed. 相似文献139.
Chartier-Harlin MC Dachsel JC Vilariño-Güell C Lincoln SJ Leprêtre F Hulihan MM Kachergus J Milnerwood AJ Tapia L Song MS Le Rhun E Mutez E Larvor L Duflot A Vanbesien-Mailliot C Kreisler A Ross OA Nishioka K Soto-Ortolaza AI Cobb SA Melrose HL Behrouz B Keeling BH Bacon JA Hentati E Williams L Yanagiya A Sonenberg N Lockhart PJ Zubair AC Uitti RJ Aasly JO Krygowska-Wajs A Opala G Wszolek ZK Frigerio R Maraganore DM Gosal D Lynch T Hutchinson M Bentivoglio AR Valente EM Nichols WC Pankratz N 《American journal of human genetics》2011,(3):140-406
Genome-wide analysis of a multi-incident family with autosomal-dominant parkinsonism has implicated a locus on chromosomal region 3q26-q28. Linkage and disease segregation is explained by a missense mutation c.3614G>A (p.Arg1205His) in eukaryotic translation initiation factor 4-gamma (EIF4G1). Subsequent sequence and genotype analysis identified EIF4G1 c.1505C>T (p.Ala502Val), c.2056G>T (p.Gly686Cys), c.3490A>C (p.Ser1164Arg), c.3589C>T (p.Arg1197Trp) and c.3614G>A (p.Arg1205His) substitutions in affected subjects with familial parkinsonism and idiopathic Lewy body disease but not in control subjects. Despite different countries of origin, persons with EIF4G1 c.1505C>T (p.Ala502Val) or c.3614G>A (p.Arg1205His) mutations appear to share haplotypes consistent with ancestral founders. eIF4G1 p.Ala502Val and p.Arg1205His disrupt eIF4E or eIF3e binding, although the wild-type protein does not, and render mutant cells more vulnerable to reactive oxidative species. EIF4G1 mutations implicate mRNA translation initiation in familial parkinsonism and highlight a convergent pathway for monogenic, toxin and perhaps virally-induced Parkinson disease. 相似文献
140.
Katrijn Van Laere Soraya C. França Hein Vansteenkiste Johan Van Huylenbroeck Kathy Steppe Marie-Christine Van Labeke 《Acta Physiologiae Plantarum》2011,33(4):1149-1156
In this study, we analysed morphological, anatomical and physiological effects of polyploidisation in Spathiphyllum
wallisii in order to evaluate possible interesting advantages of polyploids for ornamental breeding. Stomatal density was negatively
correlated with increased ploidy level. Stomatal size increased in polyploids. Tetraploid Spathiphyllum plants had more ovate and thicker leaves. The inflorescence of tetraploids had a more ovate and thicker spathum, a more cylindrical
spadix and a thicker but shorter flower stalk. Biomass production of the tetraploids was reduced, as expressed by lower total
dry weights, and tetraploids produced fewer shoots and leaves compared with their diploid progenitors. Furthermore, tetraploid
Spathiphyllum plants were more resistant to drought stress compared with diploid plants. After 15 days of drought stress, diploids showed
symptoms of wilting, while the tetraploids showed almost no symptoms. Further, measurements of stomatal resistance, leaf water
potential, relative water content and proline content indicated that the tetraploid genotypes were more resistant to drought
stress compared with the diploids. 相似文献