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排序方式: 共有401条查询结果,搜索用时 15 毫秒
1.
Maxime Willems Mieke Boone Marjolein Couvreur Katrien De Mulder Jelka Van Ranst Tom Artois Gaëtan Borgonie 《Development genes and evolution》2009,219(5):273-279
A method for studying whole mount flatworm embryos based on freeze-cracking of the eggs is described. This method allows successful
immunohistological and immunocytological studies of whole mount embryos. It does not require the use of sharpened needles
or a microinjection system to puncture the eggshell. Moreover, this method is more practical and less time-consuming than
classical puncturing and much cheaper than the use of a microinjection system. The advantages of this method are illustrated
by results of several immunolocalisation experiments in the macrostomid flatworm Macrostomum lignano. The optimal procedure and crucial steps for this method are discussed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Sabrina I?igo Astrid Nagels Durand Andrés Ritter Sabine Le Gall Martin Termathe Roland Klassen Takayuki Tohge Barbara De Coninck Jelle Van Leene Rebecca De Clercq Bruno P.A. Cammue Alisdair R. Fernie Kris Gevaert Geert De Jaeger Sebastian A. Leidel Raffael Schaffrath Mieke Van Lijsebettens Laurens Pauwels Alain Goossens 《Plant physiology》2016,172(2):858-873
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Richard B. Pouw Mieke C. Brouwer Judy Geissler Laurens V. van Herpen Sacha S. Zeerleder Walter A. Wuillemin Diana Wouters Taco W. Kuijpers 《PloS one》2016,11(3)
The major human complement regulator in blood, complement factor H (FH), has several closely related proteins, called FH-related (FHR) proteins. As all FHRs lack relevant complement regulatory activity, their physiological role is not well understood. FHR protein 3 (FHR-3) has been suggested to compete with FH for binding to Neisseria meningitidis, thereby affecting complement-mediated clearance. Clearly, the in vivo outcome of such competition greatly depends on the FH and FHR-3 concentrations. While FH levels have been established, accurate FHR-3 levels were never unequivocally reported to date. Moreover, CFHR3 gene copy numbers commonly vary, which may impact the FHR-3 concentration. Hence, we generated five anti-FHR-3 mAbs to specifically measure FHR-3 in human healthy donors of which we determined the gene copy number variation at the CFH/CFHR locus. Finally, we examined the acute-phase response characteristics of FHR-3 in a small sepsis cohort. We determined FHR-3 levels to have a mean of 19 nM and that under normal conditions the copy number of CFHR3 correlates to a very large extent with the FHR-3 serum levels. On average, FHR-3 was 132-fold lower compared to the FH concentration in the same serum samples and FHR-3 did not behave as a major acute phase response protein. 相似文献
5.
Lipids revert inert Abeta amyloid fibrils to neurotoxic protofibrils that affect learning in mice 总被引:1,自引:0,他引:1 下载免费PDF全文
Martins IC Kuperstein I Wilkinson H Maes E Vanbrabant M Jonckheere W Van Gelder P Hartmann D D'Hooge R De Strooper B Schymkowitz J Rousseau F 《The EMBO journal》2008,27(1):224-233
Although soluble oligomeric and protofibrillar assemblies of Abeta-amyloid peptide cause synaptotoxicity and potentially contribute to Alzheimer's disease (AD), the role of mature Abeta-fibrils in the amyloid plaques remains controversial. A widely held view in the field suggests that the fibrillization reaction proceeds 'forward' in a near-irreversible manner from the monomeric Abeta peptide through toxic protofibrillar intermediates, which subsequently mature into biologically inert amyloid fibrils that are found in plaques. Here, we show that natural lipids destabilize and rapidly resolubilize mature Abeta amyloid fibers. Interestingly, the equilibrium is not reversed toward monomeric Abeta but rather toward soluble amyloid protofibrils. We characterized these 'backward' Abeta protofibrils generated from mature Abeta fibers and compared them with previously identified 'forward' Abeta protofibrils obtained from the aggregation of fresh Abeta monomers. We find that backward protofibrils are biochemically and biophysically very similar to forward protofibrils: they consist of a wide range of molecular masses, are toxic to primary neurons and cause memory impairment and tau phosphorylation in mouse. In addition, they diffuse rapidly through the brain into areas relevant to AD. Our findings imply that amyloid plaques are potentially major sources of soluble toxic Abeta-aggregates that could readily be activated by exposure to biological lipids. 相似文献
6.
Ramireddy Eswarayya Nelissen Hilde Leuendorf Jan Erik Van Lijsebettens Mieke Inzé Dirk Schmülling Thomas 《Plant molecular biology》2021,106(6):555-567
Plant Molecular Biology - Root-specific expression of a cytokinin-degrading CKX gene in maize roots causes formation of a larger root system leading to higher element content in shoot organs. The... 相似文献
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Susan Kühnast Mieke C. Louwe Mattijs M. Heemskerk Elsbet J. Pieterman Jan B. van Klinken Sjoerd A. A. van den Berg Johannes W. A. Smit Louis M. Havekes Patrick C. N. Rensen José W. A. van der Hoorn Hans M. G. Princen J. Wouter Jukema 《PloS one》2013,8(6)
Objective
Niacin potently lowers triglycerides, mildly decreases LDL-cholesterol, and largely increases HDL-cholesterol. Despite evidence for an atheroprotective effect of niacin from previous small clinical studies, the large outcome trials, AIM-HIGH and HPS2-THRIVE did not reveal additional beneficial effects of niacin (alone or in combination with laropiprant) on top of statin treatment. We aimed to address this apparent discrepancy by investigating the effects of niacin without and with simvastatin on atherosclerosis development and determine the underlying mechanisms, in APOE*3Leiden.CETP mice, a model for familial dysbetalipoproteinemia (FD).Approach and Results
Mice were fed a western-type diet containing cholesterol without or with niacin (120 mg/kg/day), simvastatin (36 mg/kg/day) or their combination for 18 weeks. Similarly as in FD patients, niacin reduced total cholesterol by -39% and triglycerides by −50%, (both P<0.001). Simvastatin and the combination reduced total cholesterol (−30%; −55%, P<0.001) where the combination revealed a greater reduction compared to simvastatin (−36%, P<0.001). Niacin decreased total cholesterol and triglycerides primarily by increasing VLDL clearance. Niacin increased HDL-cholesterol (+28%, P<0.01) and mildly increased reverse cholesterol transport. All treatments reduced monocyte adhesion to the endothelium (−46%; −47%, P<0.01; −53%, P<0.001), atherosclerotic lesion area (−78%; −49%, P<0.01; −87%, P<0.001) and severity. Compared to simvastatin, the combination increased plaque stability index [(SMC+collagen)/macrophages] (3-fold, P<0.01). Niacin and the combination reduced T cells in the aortic root (−71%, P<0.01; −81%, P<0.001). Lesion area was strongly predicted by nonHDL-cholesterol (R2 = 0.69, P<0.001) and to a much lesser extent by HDL-cholesterol (R2 = 0.20, P<0.001).Conclusion
Niacin decreases atherosclerosis development mainly by reducing nonHDL-cholesterol with modest HDL-cholesterol-raising and additional anti-inflammatory effects. The additive effect of niacin on top of simvastatin is mostly dependent on its nonHDL-cholesterol-lowering capacities. These data suggest that clinical beneficial effects of niacin are largely dependent on its ability to lower LDL-cholesterol on top of concomitant lipid-lowering therapy. 相似文献9.
Eveline Wijckmans Mieke Nys Sarah Debaveye Marijke Brams Els Pardon Katrien Willegems Daniel Bertrand Jan Steyaert Rouslan Efremov Chris Ulens 《PloS one》2016,11(3)
Cys-loop receptors are membrane spanning ligand-gated ion channels involved in fast excitatory and inhibitory neurotransmission. Three-dimensional structures of these ion channels, determined by X-ray crystallography or electron microscopy, have revealed valuable information regarding the molecular mechanisms underlying ligand recognition, channel gating and ion conductance. To extend and validate the current insights, we here present promising candidates for further structural studies. We report the biochemical and functional characterization of Cys-loop receptor homologues identified in the proteome of Alvinella pompejana, an extremophilic, polychaete annelid found in hydrothermal vents at the bottom of the Pacific Ocean. Seven homologues were selected, named Alpo1-7. Five of them, Alpo2-6, were unidentified prior to this study. Two-electrode voltage clamp experiments revealed that wild type Alpo5 and Alpo6, both sharing remarkably high sequence identity with human glycine receptor α subunits, are anion-selective channels that can be activated by glycine, GABA and taurine. Furthermore, upon expression in insect cells fluorescence size-exclusion chromatography experiments indicated that four homologues, Alpo1, Alpo4, Alpo6 and Alpo7, can be extracted out of the membrane by a wide variety of detergents while maintaining their oligomeric state. Finally, large-scale purification efforts of Alpo1, Alpo4 and Alpo6 resulted in milligram amounts of biochemically stable and monodisperse protein. Overall, our results establish the evolutionary conservation of glycine receptors in annelids and pave the way for future structural studies. 相似文献
10.
Mieke M. E. Huijbers Jenny W. Wu Adrie H. Westphal Willem J. H. van Berkel 《Biotechnology journal》2019,14(5)
Thermus thermophilus proline dehydrogenase ( TtProDH) catalyzes the first step in proline catabolism. The thermostable flavoenzyme consists of a distorted triosephosphate isomerase (TIM) barrel and three N‐terminal helices: αA, αB, and αC. Using maltose‐binding protein (MBP) fused constructs, it has been recently demonstrated that helix αC is crucial for TtProDH catalysis and for tetramerization through positioning of helix α8. Here, the structural features that determine the thermostability of TtProDH are reported. Selective disruption of two ion pairs in the dimerization interface of several MBP‐TtProDH variants result in the formation of monomers. The newly created monomers have improved catalytic properties but their melting temperatures are decreased by more than 20 °C. Sequence comparison suggests that one of the ion‐pairs involved in dimerization is unique for ProDHs from Thermus species. In summary, intermolecular ion‐pairs improve the thermostability of TtProDH and a trade‐off is made between thermostability and catalytic activity. 相似文献