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151.
152.
Jeroen CW Rijk Ad ACM Peijnenburg Peter JM Hendriksen Johan M Van Hende Maria J Groot Michel WF Nielen 《BMC veterinary research》2010,6(1):44
Background
Within the European Union the use of growth promoting agents in animal production is prohibited. Illegal use of natural prohormones like dehydroepiandrosterone (DHEA) is hard to prove since prohormones are strongly metabolized in vivo. In the present study, we investigated the feasibility of a novel effect-based approach for monitoring abuse of DHEA. Changes in gene expression profiles were studied in livers of bull calves treated orally (PO) or intramuscularly (IM) with 1000 mg DHEA versus two control groups, using bovine 44K DNA microarrays. In contrast to controlled genomics studies, this work involved bovines purchased at the local market on three different occasions with ages ranging from 6 to 14 months, thereby reflecting the real life inter-animal variability due to differences in age, individual physiology, season and diet. 相似文献153.
Hof D Cheung K de Rooij DJ van den Hoogen FH Pruijn GJ van Venrooij WJ Raats JM 《Arthritis research & therapy》2005,7(2):R302-R309
Modifications occurring on autoantigens during cell death have been proposed to have a role in the initiation of autoimmune
diseases. Patients suffering from mixed connective tissue disease (MCTD) produce autoantibodies directed to U1 small nuclear
ribonucleoprotein (snRNP), and antibodies against a 70 kDa protein component, the U1-70K (70K) protein, are the most prominent.
During apoptosis, 70K is cleaved by caspase-3 to a 40 kDa product, which remains associated with the complex. Autoantibodies
preferentially recognizing the apoptotic form of 70K have been described previously, and an apoptosis-specific epitope on
70K has been identified. This study shows that 29 of 53 (54%) MCTD sera preferentially recognize the apoptotic form of 70K
over intact 70K. Moreover, we show that antibodies directed to an apoptosis-specific epitope on 70K are more specifically
associated with MCTD than other anti-70K antibodies, suggesting that apoptotic 70K is a better antigen for the detection of
these antibodies in MCTD patients. Longitudinal analysis of 12 MCTD patients showed in several patients that early sera are
relatively enriched with antibodies recognizing an apoptosis-specific epitope, and that the levels of these apoptosis-specific
antibodies decrease in time. These findings indicate that the early detection of apoptotic 70K is of considerable interest
for anti-U1 snRNP-positive patients. 相似文献
154.
Zhenya P. Yordanova Elena T. Iakimova Simona M. Cristescu Frans JM Harren Veneta M. Kapchina‐Toteva Ernst J. Woltering 《Cell biology international》2010,34(3):301-308
This work demonstrates a contribution of ethylene and NO (nitric oxide) in MP (mastoparan)‐induced cell death in the green algae Chlamydomonas reinhardtii. Following MP treatment, C. reinhardtii showed massive cell death, expressing morphological features of PCD (programmed cell death). A pharmacological approach involving combined treatments with MP and ethylene‐ and NO‐interacting compounds indicated the requirement of trace amounts of both ethylene and NO in MP‐induced cell death. By employing a carbon dioxide laser‐based photoacoustic detector to measure ethylene and a QCL (quantum cascade laser)‐based spectrometer for NO detection, simultaneous increases in the production of both ethylene and NO were observed following MP application. Our results show a tight regulation of the levels of both signalling molecules in which ethylene stimulates NO production and NO stimulates ethylene production. This suggests that, in conjunction with the elicitor, NO and ethylene cooperate and act synchronously in the mediation of MP‐induced PCD in C. reinhardtii. To the best of our knowledge, this is the first report on the functional significance of ethylene and NO in MP‐induced cell death. 相似文献
155.
Katrien Michiels Els JM Van Damme Guy Smagghe 《Archives of insect biochemistry and physiology》2010,73(4):193-212
Many plant lectins have high anti‐insect potential. Although the effects of most lectins are only moderately influencing development or population growth of the insect, some lectins have strong insecticidal properties. In addition, some studies report a deterrent activity towards feeding and oviposition behavior. Transmission of plant lectins to the next trophic level has been investigated for several tritrophic interactions. Effects of lectins with different sugar specificities can vary substantially with the insect species under investigation and with the experimental setup. Lectin binding in the insect is an essential step in exerting a toxic effect. Attempts have been made to study the interactions of lectins in several insect tissues and to identify lectin‐binding receptors. Ingested lectins generally bind to parts of the insect gut. Furthermore, some lectins such as the Galanthus nivalus agglutinin (GNA) cross the gut epithelium into the hemolymph and other tissues. Recently, several candidate lectin‐binding receptors have been isolated from midgut extracts. To date little is known about the exact mechanism for insecticidal activity of plant lectins. However, insect glycobiology is an emerging research field and the recent technological advances in the analysis of lectin carbohydrate specificities and insect glycobiology will certainly lead to new insights in the interactions between plant lectins and insects, and to a better understanding of the molecular mechanisms involved. © 2010 Wiley Periodicals, Inc. 相似文献
156.
John G. White Jayne M. Squirrell Kevin W. Eliceiri 《Traffic (Copenhagen, Denmark)》2001,2(11):775-780
The endomembrane system of a cell is a highly dynamic, ephemeral structure that is difficult to visualize. Reconstructions from sections of fixed material can provide high-resolution information on intercellular membrane architecture, but such techniques are fraught with artifacts and are of little help in understanding the dynamics of intracellular membrane traffic. Recently, the availability of fluorescent membrane probes and the development of techniques for optically sectioning intact specimens have allowed glimpses of membrane dynamics to be visualized in living tissue. In this review we discuss the potential of a new optical sectioning technique, multiphoton imaging, for visualizing membrane dynamics in living cells. Multiphoton microscopy offers an unparalleled ability to obtain images from deep within specimens while minimizing the effects of phototoxicity. 相似文献
157.
Kop EN Adriaansen J Smeets TJ Vervoordeldonk MJ van Lier RA Hamann J Tak PP 《Arthritis research & therapy》2006,8(5):R155-11
Synovial tissue of rheumatoid arthritis (RA) patients is characterised by an influx and retention of CD97-positive inflammatory
cells. The ligands of CD97, CD55, chondroitin sulfate B, and α5β1 (very late antigen [VLA]-5) are expressed abundantly in
the synovial tissue predominantly on fibroblast-like synoviocytes, endothelium, and extracellular matrix. Based upon this
expression pattern, we hypothesise CD97 expression to result in accumulation of inflammatory cells in the synovial tissue
of RA patients. To determine the therapeutic effect of blocking CD97 in an animal model of RA, collagen-induced arthritis
was induced in a total of 124 DBA/J1 mice. Treatment was started on day 21 (early disease) or on day 35 (longstanding disease)
with the blocking hamster anti-mouse CD97 monoclonal antibody (mAb) 1B2, control hamster immunoglobulin, or NaCl, applied
intraperitoneally three times a week. The paws were evaluated for clinical signs of arthritis and, in addition, examined by
radiological and histological analysis. Mice receiving 0.5 mg CD97 mAb starting from day 21 had significantly less arthritis
activity and hind paw swelling. Furthermore, joint damage and inflammation were reduced and granulocyte infiltration was decreased.
When treatment was started on day 35, CD97 mAb treatment had similar effects, albeit less pronounced. The results support
the notion that CD97 contributes to synovial inflammation and joint destruction in arthritis. 相似文献
158.
159.
Martijn van Zanten Federico Tessadori Laurens Bossen Anton JM Peeters Paul Fransz 《Plant signaling & behavior》2010,5(12):1677-1678
Arabidopsis thaliana is widely used as a model to study chromatin compaction dynamics during development and in response to the environment. Signals such as prolonged heat treatment, low light and pathogen infestation are known to induce large-scale de-condensation of nuclear chromatin. Here we demonstrate that the response to different environments varies at the nucleosomal level. Our results show that in contrast to previous reports on heat and biotic infestation, low light intensity signaling does not alter nucleosomal occupancy, despite the marked effects of low light on global chromatin compaction.Key words: Arabidopsis, chromatin, nucleosomes, MNase IThanks to its relatively simple chromatin organization, Arabidopsis thaliana became the model of choice to study dynamics in nuclear chromatin compaction in plants.1–3 At the microscopic level, highly condensed ‘heterochromatic’ domains (chromocenters), containing compact DNA (mainly repetitive sequences), and less condensed gene-rich ‘euchromatic’ domains can be distinguished upon staining with DAPI (4′,6-diamidino-2-phenylindole). This division however, is not static and compaction changes throughout development (reviewed in ref. 4). Chromatin for example de-condensates prior to flowering5 and increases with cell differentiation during leaf maturation3 and seedling establishment.6 Vice versa, artificially induced cell de-differentiation during protoplastization, results in loosening of compact chromatin.7,8 Chromatin compaction is also influenced by various environmental signals. These include infestation by pathogenic microorganisms such as Pseudomonas syringae, light and heat signals.9–11In our recent paper, published in Plant Physiology,12 we demonstrate that a ∼90% decrease in light intensity (low light) induces a reversible reduction in global chromatin compaction. In addition, also specifically lowering the blue-light wavelengths in the spectrum, or lowering the red-to-far red (R/Fr) ratio induced a significant reduced compaction of the nuclear chromatin. This is interesting from a functional perspective because (1) these are the relevant signals perceived by plants in natural shade conditions occurring in dense-vegetations and (2) because these wavelengths are specifically detected by the light-sensitive photoreceptor proteins. Previously, we demonstrated that the R/Fr-photoreceptor Phytochrome-B (PhyB) is a positive regulator of chromatin compaction in standard light conditions.10 We now showed that PhyB also controls low light-induced chromatin organization, but that its effect depend on the genetic background of the phyb mutant under study. Likely, PhyB exerts its effects on light-mediated chromatin compaction via stabilization of CRYPTOCHROME 2 (CRY2) protein. This chromatin-associated blue light photoreceptor is a general positive regulator of low light-induced chromatin de-compaction and in addition controls chromatin compaction during floral transition.5In addition, we demonstrated that global chromatin de-compaction during floral transition and low light treatment also occurs in euchromatic domains.5,12 To study possible chromatin changes at the nucleosomal level, we performed Micrococcal Nuclease I (MNase I) analysis. No differences were observed in the nucleosomal occupancy between standard and low light conditions in DNA gels or Southern blots hybridized with different probes for repeated sequences associated to heterochromatin, and dispersed upon low light treatment (Fig. 1). This suggests that the large-scale heterochromatin (de)compaction response observed at the microscopic level under low light conditions is not necessarily accompanied by nucleosomal displacement. These results are in line with the de-condensation conditions induced by protoplastization, where no changes in H3K9Me2 or in DNA methylation (5-mC) levels were found.7 However, these results are in contrast to the results of Pecinka and colleagues,11 who demonstrated that prolonged heat stress results in heterochromatin de-condensation and loss of nucleosomes. Moreover, it is in contrast with Pavet and co-workers,9 who found reduced 5-mC levels upon infection with P. syringae. Although the results of Pecinka and colleaugues11 were obtained by real-time PCR which may be more sensitive than our Southern blots, we conclude that the response of plants to their environment at the chromatin compaction level may be tailored to the specific signal it is confronted with and that this probably can be dissected at the nucleosomal level.Open in a separate windowFigure 1MNase I analysis of low light treated plants. Southern blots with 3 different probes hybridized to DNA from Col-0 plants cultured under standard (200 µmol m−2 s−1; control) and low light (15 µmol m−2 s−1) conditions. For each part, the first two lanes represent control DNA samples (no MNase I), followed by lanes with increasing MNase I concentrations (0.02, 0.1, 0.75 and 3 units MNase I). (A) 5S rDNA probe, (B) 45S rDNA probe, (C) pAl1 probe (180 bp centromeric repeat). M = molecular weight marker. 相似文献
160.
A genomics-informed,SNP association study reveals FBLN1 and FABP4 as contributing to resistance to fleece rot in Australian Merino sheep 总被引:1,自引:0,他引:1
Wendy JM Smith Yutao Li Aaron Ingham Eliza Collis Sean M McWilliam Tom J Dixon Belinda J Norris Suzanne I Mortimer Robert J Moore Antonio Reverter 《BMC veterinary research》2010,6(1):27