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31.
Ceramide: physiological and pathophysiological aspects 总被引:3,自引:0,他引:3
Schenck M Carpinteiro A Grassmé H Lang F Gulbins E 《Archives of biochemistry and biophysics》2007,462(2):171-175
Ceramide generated in the cell membrane has been shown to be central for the induction of apoptosis by death receptors and many stress stimuli such as gamma-irradiation, UV-light or infection with pathogens. Ceramide reorganizes cell membranes and forms large ceramide-enriched membrane domains that serve the spatial and temporal organization of the cellular signalosome upon activation. Thus, ceramide-enriched membrane domains mediate clustering of CD95 and DR5 to facilitate apoptosis, and they are also critically involved in apoptosis after irradiation, UV-light and infection with Pseudomonas aeruginosa. Since ceramide-enriched membrane domains amplify signals, their function is not restricted to the induction of apoptosis and it was shown that ceramide-enriched membrane domains are also involved in internalization of pathogens and the control of cytokine release from infected epithelial cells. Recent studies support the notion that changes of the ceramide metabolism are also critically involved in human diseases, for instance neurological disorders, cancer, infectious diseases and Wilson's disease. 相似文献
32.
Lang PA Schenck M Nicolay JP Becker JU Kempe DS Lupescu A Koka S Eisele K Klarl BA Rübben H Schmid KW Mann K Hildenbrand S Hefter H Huber SM Wieder T Erhardt A Häussinger D Gulbins E Lang F 《Nature medicine》2007,13(2):164-170
Wilson disease is caused by accumulation of Cu(2+) in cells, which results in liver cirrhosis and, occasionally, anemia. Here, we show that Cu(2+) triggers hepatocyte apoptosis through activation of acid sphingomyelinase (Asm) and release of ceramide. Genetic deficiency or pharmacological inhibition of Asm prevented Cu(2+)-induced hepatocyte apoptosis and protected rats, genetically prone to develop Wilson disease, from acute hepatocyte death, liver failure and early death. Cu(2+) induced the secretion of activated Asm from leukocytes, leading to ceramide release in and phosphatidylserine exposure on erythrocytes, events also prevented by inhibition of Asm. Phosphatidylserine exposure resulted in immediate clearance of affected erythrocytes from the blood in mice. Accordingly, individuals with Wilson disease showed elevated plasma levels of Asm, and displayed a constitutive increase of ceramide- and phosphatidylserine-positive erythrocytes. Our data suggest a previously unidentified mechanism for liver cirrhosis and anemia in Wilson disease. 相似文献
33.
34.
Arijit Mukhopadhyay Jamie M. Kramer Gerard Merkx Dorien Lugtenberg Dominique F. Smeets Merel A. W. Oortveld Ellen A. W. Blokland Jyoti Agrawal Annette Schenck Hans van Bokhoven Erik Huys Eric F. Schoenmakers Ad Geurts van Kessel C. Erik van Nouhuys Frans P. M. Cremers 《Human genetics》2010,128(3):281-291
35.
Background
Two-dimensional data colourings are an effective medium by which to represent three-dimensional data in two dimensions. Such "color-grid" representations have found increasing use in the biological sciences (e.g. microarray 'heat maps' and bioactivity data) as they are particularly suited to complex data sets and offer an alternative to the graphical representations included in traditional statistical software packages. The effectiveness of color-grids lies in their graphical design, which introduces a standard for customizable data representation. Currently, software applications capable of generating limited color-grid representations can be found only in advanced statistical packages or custom programs (e.g. micro-array analysis tools), often associated with steep learning curves and requiring expert knowledge. 相似文献36.
37.
38.
Joint Report of the First International Comparison Test on Swine Lymphocyte Alloantigens (SLA) 总被引:5,自引:0,他引:5
CH. RENARD B. KRISTENSEN C. GAUTSCHI V. HRUBAN M. FREDHOLM M. VAIMAN 《Animal genetics》1988,19(1):63-72
The first international comparison test on swine lymphocyte alloantigens (SLA) was held in Helsinki, Finland in July 1986. The results reported were based on a comparison of 157 alloantisera originating from six laboratories. The antisera were tested against a selected panel of 264 lymphocyte samples belonging to four laboratories. The most common breeds in Europe were chosen for this first comparison test (Landrace and Large White). Eighteen of the 31 previously known specificities were confirmed and a new nomenclature was established. 相似文献
39.
Group I introns are proposed to have become mobile following the
acquisition of open reading frames (ORFs) that encode highly specific DNA
endonucleases. This proposal implies that intron ORFs could behave as
autonomously mobile entities. This was supported by abundant circumstantial
evidence but no experiment of ORF transfer from an ORF- containing intron
to its ORF-less counterpart has been described. In this paper we present
such experiments, which demonstrate the efficient mobility of the
mitochondrial nad1-i4-orf1 between two Podospora strains. The homing of
this mobile ORF was accompanied by a bidirectional co-conversion that did
not systematically involve the whole intron sequence. Orf1 acquisition
would be the most recent step in the evolution of the nad1-i4 intron, which
has resulted in many strains of Podospora having an intron with two ORFs
(biorfic) and four splicing pathways. We show that two of the splicing
events that operate in this biorfic intron, as evidenced by PCR
experiments, are generated by a 5'-alternative splice site, which is most
probably a remnant of the monoorfic ancestral form of the intron. We
propose a sequential evolution model that is consistent with the four
organizations of the corresponding nad1 locus that we found among various
species of the Pyrenomycete family; these organizations consist of no
intron, an intron alone, a monoorfic intron, and a biorfic intron.
相似文献
40.
The relationship between plant species diversity and ecosystem CO2 and water vapour fluxes was investigated for planted calcareous grassland communities composed of 5, 12, or 32 species assembled from the native plant species pool. These diversity manipulations were done in factorial combination with a CO2 enrichment experiment in order to investigate the degree to which ecosystem responses to elevated CO2 are altered by a loss of plant diversity. Ecosystem CO2 and H2O fluxes were measured over several 24-h periods during the 1994 and 1995 growing seasons. Ecosystem CO2 assimilation on a ground area basis decreased with decreasing plant diversity in the first year and this was related to a decline in above-ground plant biomass. In the second year, however, CO2 assimilation was not affected by diversity, and this corresponded to the disappearance of a diversity effect on above-ground biomass. Irrespective of diversity treatment, CO2 assimilation on a ground area basis was linearly related to peak above-ground biomass in both years. Elevated CO2 significantly increased ecosystem CO2 assimilation in both years with no interaction between diversity and CO2 treatment, and no corresponding increase in above-ground biomass. There were no significant effects of diversity on water vapour flux, which was measured only in the second year. There were indications of a small CO2 effect on water vapour flux (3–9% lower at elevated CO2 depending on the light level). Our findings suggest that decreasing plant species diversity may substantially decrease ecosystem CO2 assimilation during the establishment of such planted calcareous grassland communities, but also suggest that this effect may not persist. In addition, we find no evidence that plant species diversity alters the response of ecosystem CO2 assimilation to elevated CO2. 相似文献