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排序方式: 共有387条查询结果,搜索用时 15 毫秒
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Maragno AL Pironin M Alcalde H Cong X Knobeloch KP Tangy F Zhang DE Ghysdael J Quang CT 《PloS one》2011,6(10):e26068
Activation of erythropoietin receptor allows erythroblasts to generate erythrocytes. In a search for genes that are up-regulated during this differentiation process, we have identified ISG15 as being induced during late erythroid differentiation. ISG15 belongs to the ubiquitin-like protein family and is covalently linked to target proteins by the enzymes of the ISGylation machinery. Using both in vivo and in vitro differentiating erythroblasts, we show that expression of ISG15 as well as the ISGylation process related enzymes Ube1L, UbcM8 and Herc6 are induced during erythroid differentiation. Loss of ISG15 in mice results in decreased number of BFU-E/CFU-E in bone marrow, concomitant with an increased number of these cells in the spleen of these animals. ISG15(-/-) bone marrow and spleen-derived erythroblasts show a less differentiated phenotype both in vivo and in vitro, and over-expression of ISG15 in erythroblasts is found to facilitate erythroid differentiation. Furthermore, we have shown that important players of erythroid development, such as STAT5, Globin, PLC γ and ERK2 are ISGylated in erythroid cells. This establishes a new role for ISG15, besides its well-characterized anti-viral functions, during erythroid differentiation. 相似文献
34.
SUMMARY: IQPNNI is a program to infer maximum-likelihood phylogenetic trees from DNA or protein data with a large number of sequences. We present an improved and MPI-parallel implementation showing very good scaling and speed-up behavior. 相似文献
35.
Scaffolding proteins exist in eukaryotes to properly assemble signaling proteins into specific multimeric functional complexes. JLP is a novel leucine zipper protein belonging to a family of scaffolding proteins that assemble JNK signaling modules. JLP is a proline-rich protein that contains two leucine zipper domains and a highly conserved C-terminal domain. We have identified kinesin light chain 1 (KLC1) as a binding partner for the second leucine zipper domain of JLP using yeast two-hybrid screening. The interaction domain of KLC1 was mapped to its tetratripeptide repeat, which contains a novel leucine zipper-like domain that is crucial for the interaction with JLP. Mutations of Leu-280, Leu-287, Val-294, and Leu-301 within this domain of KLC1 disrupted its ability to associate with JLP. Immunofluorescence studies showed that JLP and KLC1 co-localized in the cytoplasm and that the localization of JLP was dependent on its second leucine zipper. Ectopic expression of a dominant negative form of KLC1 resulted in the mislocalization of endogenous JLP. Moreover, the association between JLP and KLC1 occurred in vivo and was important in the formation of ternary complex with JNK1. These results identify a novel protein-protein interaction between KLC1 and JLP that involves leucine zipper-like domains and support the role of motor proteins in the spatial regulation of signaling modules. 相似文献
36.
Choy JS Dang Q Molloi S Kassab GS 《American journal of physiology. Heart and circulatory physiology》2006,290(4):H1558-H1565
The pressure-induced remodeling of coronary veins is important in coronary venous retroperfusion. Our hypothesis is that the response of the large coronary veins to pressure overload will depend on the degree of myocardial support. Eleven normal Yorkshire swine from either sex, weighing 31-39 kg, were studied. Five pigs underwent ligation of the left anterior descending (LAD) vein, and six served as sham-operated controls. The ligation of the coronary vein caused an increase in pressure intermediate to arterial and venous values. After 2 wk of ligation, the animals were euthanized and the coronary vessels were perfusion-fixed with glutaraldehyde. The LAD vein was sectioned, and detailed morphometric measurements were made along its length from the point of ligation near the base down to the apex of the heart. The structural remodeling of the vein was circumferentially nonuniform because the vein is partially embedded in the myocardium; it was also axially nonuniform because it is tethered to the myocardium to different degrees along its axial length. The wall area was significantly larger in the experimental group, whereas luminal area in the proximal LAD vein was significantly smaller in the same group compared with sham-operated controls. The wall thickness-to-radius ratio was also significantly larger in the experimental group in proportion to the increase in pressure. The major conclusion of this study is that the response of the vein depends on the local wall stress, which is, in part, determined by the surrounding tissue. Furthermore, the geometric remodeling of the coronary vein restores the circumferential stress to the homeostatic value. 相似文献
37.
Braun D Galibert L Nakajima T Saito H Quang VV Rubio M Sarfati M 《Journal of immunology (Baltimore, Md. : 1950)》2006,177(12):8550-8559
CD47 on live cells actively engages signal-regulatory protein-alpha (SIRP-alpha) on phagocytes and delivers a negative signal that prevents their elimination. We evaluated the biological consequences of SIRP-alpha ligation on the dendritic cell (DC) response to maturation signals and the potential interplay with the IL-10/IL-10R inhibitory pathway. At first, CD47/SIRP-alpha allowed the generation of mature migratory DCs not producing IL-12, IFN-gamma-inducible protein-10, and CCL19. Rather, they secreted neutrophils attracting chemokine CXCL5 and IL-1beta, reflecting a partial block in functional DC maturation. Afterward, semimature DCs functionally regressed in an IL-10-independent fashion toward cells that retrieved the cardinal features of immature DCs: re-expression of CCR5, loss of DC-lysosome-associated membrane protein, high endocytosis, and impaired allostimulatory functions. The global gene expression profile of IL-10 and SIRP-alpha-ligated DC demonstrated two distinct molecular pathways. IL-10R and SIRP-alpha expression were reciprocally down-regulated by CD47 and IL-10, respectively. These results emphasize that the SIRP-alpha pathway might be part of the molecular machinery used by the DC to dampen or resolve an inflammatory response in an IL-10-independent manner. 相似文献
38.
Andrew Wilby La Pham Lan Kong Luen Heong Nguyen Phi Dieu Huyen Nguyen Huu Quang Nguyen Viet Minh Matt. B Thomas 《Ecosystems》2006,9(4):538-549
Declining biodiversity in agro-ecosystems, caused by intensification of production or expansion of monocultures, is associated
with the emergence of agricultural pests. Understanding how land-use and management control crop-associated biodiversity is,
therefore, one of the key steps towards the prediction and maintenance of natural pest-control. Here we report on relationships
between land-use variables and arthropod community attributes (for example, species diversity, abundance and guild structure)
across a diversification gradient in a rice-dominated landscape in the Mekong delta, Vietnam. We show that rice habitats contained
the most diverse arthropod communities, compared with other uncultivated and cultivated land-use types. In addition, arthropod
species density and Simpson’s diversity in flower, vegetable and fruit habitats was positively related to rice cover in the
local landscape. However, across the landscape as a whole, reduction in heterogeneity and the amount of uncultivated cover
was associated, generally, with a loss of diversity. Furthermore, arthropod species density in tillering and flowering stages
of rice was positively related to crop and vegetation richness, respectively, in the local landscape. Differential effects
on feeding guilds were also observed in rice-associated communities with the proportional abundance of predators increasing
and the proportional abundance of detritivores decreasing with increased landscape rice cover. Thus, we identify a range of
rather complex, sometimes contradictory patterns concerning the impact of rice cover and landscape heterogeneity on arthropod
community attributes. Importantly, we conclude that that land-use change associated with expansion of monoculture rice need
not automatically impact diversity and functioning of the arthropod community. 相似文献
39.
Fatal outcome of human influenza A (H5N1) is associated with high viral load and hypercytokinemia 总被引:1,自引:0,他引:1
de Jong MD Simmons CP Thanh TT Hien VM Smith GJ Chau TN Hoang DM Chau NV Khanh TH Dong VC Qui PT Cam BV Ha do Q Guan Y Peiris JS Chinh NT Hien TT Farrar J 《Nature medicine》2006,12(10):1203-1207
Avian influenza A (H5N1) viruses cause severe disease in humans, but the basis for their virulence remains unclear. In vitro and animal studies indicate that high and disseminated viral replication is important for disease pathogenesis. Laboratory experiments suggest that virus-induced cytokine dysregulation may contribute to disease severity. To assess the relevance of these findings for human disease, we performed virological and immunological studies in 18 individuals with H5N1 and 8 individuals infected with human influenza virus subtypes. Influenza H5N1 infection in humans is characterized by high pharyngeal virus loads and frequent detection of viral RNA in rectum and blood. Viral RNA in blood was present only in fatal H5N1 cases and was associated with higher pharyngeal viral loads. We observed low peripheral blood T-lymphocyte counts and high chemokine and cytokine levels in H5N1-infected individuals, particularly in those who died, and these correlated with pharyngeal viral loads. Genetic characterization of H5N1 viruses revealed mutations in the viral polymerase complex associated with mammalian adaptation and virulence. Our observations indicate that high viral load, and the resulting intense inflammatory responses, are central to influenza H5N1 pathogenesis. The focus of clinical management should be on preventing this intense cytokine response, by early diagnosis and effective antiviral treatment. 相似文献
40.
Christian S Head Quang Luu Joel Sercarz Romaine Saxton 《World journal of surgical oncology》2006,4(1):1-10