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51.
Maria Katsogiannou Charbel El Boustany Florian Gackiere Philippe Delcourt Anne Athias Pascal Mariot Etienne Dewailly Nathalie Jouy Christophe Lamaze Gabriel Bidaux Brigitte Mauroy Natalia Prevarskaya Christian Slomianny 《PloS one》2009,4(9)
Background
During androgen ablation prostate cancer cells'' growth and survival become independent of normal regulatory mechanisms. These androgen-independent cells acquire the remarkable ability to adapt to the surrounding microenvironment whose factors, such as neurotransmitters, influence their survival. Although findings are becoming evident about the expression of α1A-adrenoceptors in prostate cancer epithelial cells, their exact functional role in androgen-independent cells has yet to be established. Previous work has demonstrated that membrane lipid rafts associated with key signalling proteins mediate growth and survival signalling pathways in prostate cancer cells.Methodology/Principal Findings
In order to analyze the membrane topology of the α1A-adrenoceptor we explored its presence by a biochemical approach in purified detergent resistant membrane fractions of the androgen-independent prostate cancer cell line DU145. Electron microscopy observations demonstrated the colocalisation of the α1A-adrenoceptor with caveolin-1, the major protein component of caveolae. In addition, we showed that agonist stimulation of the α1A-adrenoceptor induced resistance to thapsigargin-induced apoptosis and that caveolin-1 was necessary for this process. Further, immunohistofluorescence revealed the relation between high levels of α1A-adrenoceptor and caveolin-1 expression with advanced stage prostate cancer. We also show by immunoblotting that the TG-induced apoptosis resistance described in DU145 cells is mediated by extracellular signal-regulated kinases (ERK).Conclusions/Significance
In conclusion, we propose that α1A-adrenoceptor stimulation in androgen-independent prostate cancer cells via caveolae constitutes one of the mechanisms contributing to their protection from TG-induced apoptosis. 相似文献52.
Yolande Rouiller Arnaud Périlleux Natacha Collet Martin Jordan Matthieu Stettler Hervé Broly 《MABS-AUSTIN》2013,5(3):501-511
An innovative high-throughput medium development method based on media blending was successfully used to improve the performance of a Chinese hamster ovary fed-batch medium in shaking 96-deepwell plates. Starting from a proprietary chemically-defined medium, 16 formulations testing 43 of 47 components at 3 different levels were designed. Media blending was performed following a custom-made mixture design of experiments considering binary blends, resulting in 376 different blends that were tested during both cell expansion and fed-batch production phases in one single experiment. Three approaches were chosen to provide the best output of the large amount of data obtained. A simple ranking of conditions was first used as a quick approach to select new formulations with promising features. Then, prediction of the best mixes was done to maximize both growth and titer using the Design Expert software. Finally, a multivariate analysis enabled identification of individual potential critical components for further optimization. Applying this high-throughput method on a fed-batch, rather than on a simple batch, process opens new perspectives for medium and feed development that enables identification of an optimized process in a short time frame. 相似文献
53.
Matthieu Gilson Anthony N. Burkitt David B. Grayden Doreen A. Thomas J. Leo van Hemmen 《Biological cybernetics》2009,101(2):81-102
Spike-timing-dependent plasticity (STDP) determines the evolution of the synaptic weights according to their pre- and post-synaptic
activity, which in turn changes the neuronal activity. In this paper, we extend previous studies of input selectivity induced
by (STDP) for single neurons to the biologically interesting case of a neuronal network with fixed recurrent connections and
plastic connections from external pools of input neurons. We use a theoretical framework based on the Poisson neuron model
to analytically describe the network dynamics (firing rates and spike-time correlations) and thus the evolution of the synaptic
weights. This framework incorporates the time course of the post-synaptic potentials and synaptic delays. Our analysis focuses
on the asymptotic states of a network stimulated by two homogeneous pools of “steady” inputs, namely Poisson spike trains
which have fixed firing rates and spike-time correlations. The (STDP) model extends rate-based learning in that it can implement,
at the same time, both a stabilization of the individual neuron firing rates and a slower weight specialization depending
on the input spike-time correlations. When one input pathway has stronger within-pool correlations, the resulting synaptic
dynamics induced by (STDP) are shown to be similar to those arising in the case of a purely feed-forward network: the weights
from the more correlated inputs are potentiated at the expense of the remaining input connections. 相似文献
54.
M phase phosphoprotein 1 is a human plus-end-directed kinesin-related protein required for cytokinesis 总被引:4,自引:0,他引:4
Abaza A Soleilhac JM Westendorf J Piel M Crevel I Roux A Pirollet F 《The Journal of biological chemistry》2003,278(30):27844-27852
The human M phase phosphoprotein 1 (MPP1), previously identified through a screening of a subset of proteins specifically phosphorylated at the G2/M transition (Matsumoto-Taniura, N., Pirollet, F., Monroe, R., Gerace, L., and Westendorf, J. M. (1996) Mol. Biol. Cell 7, 1455-1469), is characterized as a plus-end-directed kinesin-related protein. Recombinant MPP1 exhibits in vitro microtubule-binding and microtubule-bundling properties as well as microtubule-stimulated ATPase activity. In gliding experiments using polarity-marked microtubules, MPP1 is a slow molecular motor that moves toward the microtubule plus-end at a 0.07 microm/s speed. In cycling cells, MPP1 localizes mainly to the nuclei in interphase. During mitosis, MPP1 is diffuse throughout the cytoplasm in metaphase and subsequently localizes to the midzone to further concentrate on the midbody. MPP1 suppression by RNA interference induces failure of cell division late in cytokinesis. We conclude that MPP1 is a new mitotic molecular motor required for completion of cytokinesis. 相似文献
55.
Matteo Gentili Xavier Lahaye Francesca Nadalin Guilherme P.F. Nader Emilia Puig Lombardi Solène Herve Nilushi S. De Silva Derek C. Rookhuizen Elina Zueva Christel Goudot Mathieu Maurin Aurore Bochnakian Sebastian Amigorena Matthieu Piel Daniele Fachinetti Arturo Londoño-Vallejo Nicolas Manel 《Cell reports》2019,26(13):3798
56.
da Rocha GC Harter-Lailheugue S Le Bailly M Araújo A Ferreira LF da Serra-Freire NM Bouchet F 《Memórias do Instituto Oswaldo Cruz》2006,101(Z2):43-52
Human occupation for several centuries was recorded in the archaeological layers of "Place d'Armes", Namur, Belgium. Preventive archaeological excavations were carried out between 1996/1997 and seven historical strata were observed, from Gallo-Roman period up to Modern Times. Soil samples from cesspools, latrines, and structures-like were studied and revealed intestinal parasite eggs in the different archaeological contexts. Ascaris lumbricoides, A. suum, Trichuris trichiura, T. suis. Taenia sp., Fasciola hepatica, Diphyllobothrium sp., Capillaria sp. and Oxyuris equi eggs were found. Paleoparasitology confirmed the use of structures as latrines or cesspit as firstly supposed by the archaeologists. Medieval latrines were not only used for rejection of human excrements. The finding of Ascaris sp. and Trichuris sp. eggs may point to human's or wild swine's feces. Gallo-Roman people used to eat wild boar. Therefore, both A. suum and T. suis, or A. lumbricoides and T. trichuris, may be present, considering a swine carcass recovered into a cesspit. Careful sediment analysis may reveal its origin, although parasites of domestic animals can be found together with those of human's. Taenia sp. eggs identified in latrine samples indicate ingestion of uncooked beef with cysticercoid larvae. F. hepatica eggs suggest the ingestion of raw contaminated vegetables and Diphyllobothrium sp. eggs indicate contaminated fresh-water fish consumption. Ascaris sp. and Trichuris sp. eggs indicate fecal-oral infection by human and/or animal excrements. 相似文献
57.
Dotan I Allez M Nakazawa A Brimnes J Schulder-Katz M Mayer L 《American journal of physiology. Gastrointestinal and liver physiology》2007,292(6):G1630-G1640
Previous studies have suggested that intestinal epithelial cells (IECs) have the capacity to function as nonprofessional antigen presenting cells that in the normal state preferentially activate CD8+ T cells. However, under pathological conditions, such as those found in inflammatory bowel disease (IBD), persistent activation of CD4+ T cells is seen. The aim of this study was to determine whether the IBD IECs contribute to CD4+ T cell activation. Freshly isolated human IECs were obtained from surgical specimens of patients with or without IBD and cocultured with autologous or allogeneic peripheral blood T lymphocytes. Cocultures of normal T cells and IECs derived from IBD patients resulted in the preferential activation of CD4+ T cell proliferation that was associated with significant IFN-gamma, but not IL-2, secretion. Cytokine secretion and CD4+ T cell proliferation was inhibited by pretreatment of the IBD IECs with the anti-DR MAb L243. In contrast, normal IECs stimulated the proliferation and cytokine secretion by CD4+ T cells to a significantly lesser degree than IBD IECs. Furthermore, blockade of human leukocyte antigen-DR had a lesser effect in the normal IEC-CD4+ T cell cocultures. We conclude that IECs can contribute to the ongoing CD4+ T cell activation seen in IBD. We suggest that the apparent differences between the secreted levels of IFN-gamma indicate that it may play a dual role in intestinal homeostasis, in which low levels contribute to physiological inflammation whereas higher levels are associated with an uncontrolled inflammatory state. 相似文献
58.
CNS myelin was isolated from the spinal cord of the African lungfish Protopterus dolloi. Its proteins consisted of (1) two basic proteins (16,000 and 18,500 apparent Mr) that reacted with anti-human CNS myelin basic protein antibodies and (2) a major protein (29,000 apparent Mr) that stained with concanavalin A-horseradish peroxidase and bound to anti-rat CNS myelin proteolipid protein (PLP) antibodies. This dominant 29,000 Mr protein showed no reaction with antibodies against the major bovine PNS myelin glycoprotein P0. Following treatment with endoglycosidase F the 29,000 Mr protein was reduced in size to a 26,000 apparent Mr component that no longer bound concanavalin A but retained the anti-PLP reactivity. These results agree with a concanavalin A-binding oligosaccharide linked through asparagine to a protein backbone of PLP homology. The major 29,000 Mr lungfish CNS myelin protein was therefore termed g-PLP (glycosylated proteolipid protein). This is the first report demonstrating the occurrence of a PLP-cross-reactive protein in CNS myelin of a fish. It attests to the close phylogenetic relationship of lungfishes to amphibians. Amphibians were previously recognized as the oldest class bearing PLP in its CNS myelin. 相似文献
59.
Kempf M Eveillard M Deshayes C Ghamrawi S Lefrançois C Georgeault S Bastiat G Seifert H Joly-Guillou ML 《Canadian journal of microbiology》2012,58(3):311-317
The aim of this study was to unravel, by focusing on cell surface properties, the underlying virulence factors contributing to the difference in the pathogenicity observed in two Acinetobacter baumannii strains isolated from the same patient. The two strains were phenotypically different: (i) a mucoid strain (AB-M), highly virulent in a mouse model of pneumonia, and (ii) a nonmucoid strain (AB-NM), moderately virulent in the same model. The study of the cell surface properties included the microbial adhesion to solvents method, the measurement of the electrophoretic mobility of bacteria, the analysis of biofilm formation by calcofluor white staining, the adherence to silicone catheters, and scanning electron microscopy. The AB-NM strain was more hydrophobic, more adherent to silicone catheters, and produced more biofilm than the AB-M strain. Scanning electron microscopy showed bacterial cells with a rough surface and the formation of large cell clusters for AB-NM whereas the AB-M strain had a smooth surface and formed only a few cell clusters. Contrary to the results of most previous studies, cell surface properties were not correlated to the virulence described in our experimental model, indicating that mechanisms other than adherence may be involved in the expression of A.?baumannii virulence. 相似文献
60.