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排序方式: 共有234条查询结果,搜索用时 15 毫秒
111.
Semenza GL 《Cell》2001,107(1):1-3
Hypoxia-inducible factor 1 (HIF-1) is a global regulator of cellular and systemic O(2) homeostasis in animals. A molecular basis for O(2)-regulated expression of the HIF-1 alpha subunit has now been determined, providing a mechanism for changes in gene expression in response to changes in cellular oxygenation. 相似文献
112.
Fukuda R Hirota K Fan F Jung YD Ellis LM Semenza GL 《The Journal of biological chemistry》2002,277(41):38205-38211
Stimulation of human colon cancer cells with insulin-like growth factor 1 (IGF-1) induces expression of the VEGF gene, encoding vascular endothelial growth factor. In this article we demonstrate that exposure of HCT116 human colon carcinoma cells to IGF-1 induces the expression of HIF-1 alpha, the regulated subunit of hypoxia-inducible factor 1, a known transactivator of the VEGF gene. In contrast to hypoxia, which induces HIF-1 alpha expression by inhibiting its ubiquitination and degradation, IGF-1 did not inhibit these processes, indicating an effect on HIF-1 alpha protein synthesis. IGF-1 stimulation of HIF-1 alpha protein and VEGF mRNA expression was inhibited by treating cells with inhibitors of phosphatidylinositol 3-kinase and MAP kinase signaling pathways. These inhibitors also blocked the IGF-1-induced phosphorylation of the translational regulatory proteins 4E-BP1, p70 S6 kinase, and eIF-4E, thus providing a mechanism for the modulation of HIF-1 alpha protein synthesis. Forced expression of a constitutively active form of the MAP kinase kinase, MEK2, was sufficient to induce HIF-1 alpha protein and VEGF mRNA expression. Involvement of the MAP kinase pathway represents a novel mechanism for the induction of HIF-1 alpha protein expression in human cancer cells. 相似文献
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115.
Georgios K. Nikolopoulos Anastasios Fotiou Eleftheria Kanavou Clive Richardson Marios Detsis Anastasia Pharris Jonathan E. Suk Jan C. Semenza Claudia Costa-Storti Dimitrios Paraskevis Vana Sypsa Melpomeni-Minerva Malliori Samuel R. Friedman Angelos Hatzakis 《PloS one》2015,10(4)
Background
There is sparse evidence that demonstrates the association between macro-environmental processes and drug-related HIV epidemics. The present study explores the relationship between economic, socio-economic, policy and structural indicators, and increases in reported HIV infections among people who inject drugs (PWID) in the European Economic Area (EEA).Methods
We used panel data (2003–2012) for 30 EEA countries. Statistical analyses included logistic regression models. The dependent variable was taking value 1 if there was an outbreak (significant increase in the national rate of HIV diagnoses in PWID) and 0 otherwise. Explanatory variables included the growth rate of Gross Domestic Product (GDP), the share of the population that is at risk for poverty, the unemployment rate, the Eurostat S80/S20 ratio, the Gini coefficient, the per capita government expenditure on health and social protection, and variables on drug control policy and drug-using population sizes. Lags of one to three years were investigated.Findings
In multivariable analyses, using two-year lagged values, we found that a 1% increase of GDP was associated with approximately 30% reduction in the odds of an HIV outbreak. In GDP-adjusted analyses with three-year lagged values, the effect of the national income inequality on the likelihood of an HIV outbreak was significant [S80/S20 Odds Ratio (OR) = 3.89; 95% Confidence Interval (CI): 1.15 to 13.13]. Generally, the multivariable analyses produced similar results across three time lags tested.Interpretation
Given the limitations of ecological research, we found that declining economic growth and increasing national income inequality were associated with an elevated probability of a large increase in the number of HIV diagnoses among PWID in EEA countries during the last decade. HIV prevention may be more effective if developed within national and European-level policy contexts that promote income equality, especially among vulnerable groups. 相似文献116.
Josef Brunner David E. Graham Helmut Hauser Giorgio Semenza 《The Journal of membrane biology》1980,57(2):133-141
Summary Na+ and sugar permeabilities of egg lecithin bilayers were measured using curved bilayers and planar bilayers as represented by single-bilayer vesicles and black lipid films, respectively. The Na+ permeability coefficient measured with single-bilayer vesicles at 25°C is (2.1±0.6)×10–13 cm sec–1. Because of technical difficulties it has been impossible to measure ionic permeabilities of values lower than about 10–10 cm sec–1 in planar (black) lipid bilayers using tracer methods. Thed-glucose andd-fructose permeabilities were measured with both curved and planar bilayers. The permeability coefficients measured with vesicles at 25°C are (0.3±0.2)×10–10 cm sec–1 for glucose and (4±1)×10–10 cm sec–1 ford-fructose; these are in reasonable agreement with the corresponding values obtained for planar (black) lipid bilayers which are (1.1±0.3)×10–10 cm sec–1 ford-glucose and (9.3±0.3)×10–10 cm sec–1 ford-fructose, respectively.This paper is dedicated to the memory of Walther Wilbrandt,cuius nomini nullum par elogium. 相似文献
117.
Hypoxia-inducible factor-1 deficiency results in dysregulated erythropoiesis signaling and iron homeostasis in mouse development 总被引:10,自引:0,他引:10
Yoon D Pastore YD Divoky V Liu E Mlodnicka AE Rainey K Ponka P Semenza GL Schumacher A Prchal JT 《The Journal of biological chemistry》2006,281(35):25703-25711
118.
Mitochondrial autophagy is an HIF-1-dependent adaptive metabolic response to hypoxia 总被引:6,自引:0,他引:6
Zhang H Bosch-Marce M Shimoda LA Tan YS Baek JH Wesley JB Gonzalez FJ Semenza GL 《The Journal of biological chemistry》2008,283(16):10892-10903
Autophagy is a process by which cytoplasmic organelles can be catabolized either to remove defective structures or as a means of providing macromolecules for energy generation under conditions of nutrient starvation. In this study we demonstrate that mitochondrial autophagy is induced by hypoxia, that this process requires the hypoxia-dependent factor-1-dependent expression of BNIP3 and the constitutive expression of Beclin-1 and Atg5, and that in cells subjected to prolonged hypoxia, mitochondrial autophagy is an adaptive metabolic response which is necessary to prevent increased levels of reactive oxygen species and cell death. 相似文献
119.
120.
The sucrase-isomaltase complex: primary structure, membrane-orientation, and evolution of a stalked, intrinsic brush border protein 总被引:34,自引:0,他引:34
The complete primary structure (1827 amino acids) of rabbit intestinal pro-sucrase-isomaltase (pro-SI) was deduced from the sequence of a nearly full-length cDNA. Pro-SI is anchored in the membrane by a single 20 amino acid segment spanning the bilayer only once. The amino-terminal, cytoplasmic domain consists of 12 amino acids and is not preceded by a cleaved leader sequence. This suggests a dual role for the membrane-spanning segment as an uncleaved signal for membrane insertion. This is followed by a 22 residue serine/threonine-rich, probably glycosylated, stretch, presumably forming the stalk on which the globular, catalytic domains are directed into the intestinal lumen. Following this is a high degree of homology between the isomaltase and sucrase portions (41% amino acid identity), indicating that pro-SI evolved by partial gene duplication. 相似文献