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21.
Introduction
The relative resistance of non-chondrodystrophic (NCD) canines to degenerative disc disease (DDD) may be due to a combination of anabolic and anti-catabolic factors secreted by notochordal cells within the intervertebral disc (IVD) nucleus pulposus (NP). Factors known to induce DDD include interleukin-1 beta (IL-1ß) and/or Fas-Ligand (Fas-L). Therefore we evaluated the ability of notochordal cell conditioned medium (NCCM) to protect NP cells from IL-1ß and IL-1ß +FasL-mediated cell death and degeneration.Methods
We cultured bovine NP cells with IL-1ß or IL-1ß+FasL under hypoxic serum-free conditions (3.5% O2) and treated the cells with either serum-free NCCM or basal medium (Advanced DMEM/F-12). We used flow cytometry to evaluate cell death and real-time (RT-)PCR to determine the gene expression of aggrecan, collagen 2, and link protein, mediators of matrix degradation ADAMTS-4 and MMP3, the matrix protection molecule TIMP1, the cluster of differentiation (CD)44 receptor, the inflammatory cytokine IL-6 and Ank. We then determined the expression of specific apoptotic pathways in bovine NP cells by characterizing the expression of activated caspases-3, -8 and -9 in the presence of IL-1ß+FasL when cultured with NCCM, conditioned medium obtained using bovine NP cells (BCCM), and basal medium all supplemented with 2% FBS.Results
NCCM inhibits bovine NP cell death and apoptosis via suppression of activated caspase-9 and caspase-3/7. Furthermore, NCCM protects NP cells from the degradative effects of IL-1ß and IL-1ß+Fas-L by up-regulating the expression of anabolic/matrix protective genes (aggrecan, collagen type 2, CD44, link protein and TIMP-1) and down-regulating matrix degrading genes such as MMP-3. Expression of ADAMTS-4, which encodes a protein for aggrecan remodeling, is increased. NCCM also protects against IL-1+FasL-mediated down-regulation of Ank expression. Furthermore, NP cells treated with NCCM in the presence of IL-1ß+Fas-L down-regulate the expression of IL-6 by almost 50%. BCCM does not mediate cell death/apoptosis in target bovine NP cells.Conclusions
Notochordal cell-secreted factors suppress NP cell death by inhibition of activated caspase-9 and -3/7 activity and by up-regulating genes contributing anabolic activity and matrix protection of the IVD NP. Harnessing the restorative powers of the notochordal cell could lead to novel cellular and molecular strategies in the treatment of DDD. 相似文献22.
Zhenyu Cheng Yi-Yun C Wei Wilson WL Sung Bernard R Glick Brendan J McConkey 《Proteome science》2009,7(1):18
Background
Plant growth-promoting bacteria can alleviate the inhibitory effects of various heavy metals on plant growth, via decreasing levels of stress-induced ethylene. However, little has been done to detect any mechanisms specific for heavy metal resistance of this kind of bacteria. Here, we investigate the response of the wild-type plant growth-promoting bacterium Pseudomonas putida UW4 to nickel stress using proteomic approaches. The mutant strain P. putida UW4/AcdS-, lacking a functional 1-aminocyclopropane-1-carboxylic acid deaminase gene, was also assessed for its response to nickel stress. 相似文献23.
Proliferation of direct repeats near the Oenothera chloroplast DNA origin of replication 总被引:1,自引:0,他引:1
The spacer between the 16S and 23S rRNA genes of the chloroplast DNA has
been implicated as an origin of replication in several species of plants.
In the evening primrose, Oenothera, this site was found to vary greatly in
size, with plastid genomes (plastomes) being readily distinguished. To
determine whether plastome "strength" in transmission could be correlated
with variation at oriB, the 16S rRNA-trnI spacer was sequenced from five
plastomes. The size variation was found to be due to differential
amplification (and deletion) of combinations of sequences belonging to
seven families of direct repeats. From these comparisons, one short series
of direct repeats and one region capable of forming a hairpin structure
were identified as candidates for the factor that could be responsible for
the differences between strong and weak plastome types. Ample sequence
variation allowed phylogenetic inferences to be made about the
relationships among the plastomes. Phylogenetic trees also could be
constructed for most of the families of direct repeats. The amplifications
and deletions of repeats that account for the size variation at oriB are
proposed to have occurred through extensive replication slippage at this
site.
相似文献
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Arco J Teske Bart WL De Boeck Paul G Melman Gertjan T Sieswerda Pieter A Doevendans Maarten JM Cramer 《Cardiovascular ultrasound》2007,5(1):1-19
Recent developments in the field of echocardiography have allowed the cardiologist to objectively quantify regional and global myocardial function. Regional deformation (strain) and deformation rate (strain-rate) can be calculated non-invasively in both the left and right ventricle, providing information on regional (dys-)function in a variety of clinical settings. Although this promising novel technique is increasingly applied in clinical and preclinical research, knowledge about the principles, limitations and technical issues of this technique is mandatory for reliable results and for implementation both in the clinical as well as the scientific field. In this article, we aim to explain the fundamental concepts and potential clinical applicability of strain and strain-rate for both tissue Doppler imaging (TDI) derived and speckle tracking (2D-strain) derived deformation imaging. In addition, a step-by-step approach to image acquisition and post processing is proposed. Finally, clinical examples of deformation imaging in hypertrophic cardiomyopathy (HCM), cardiac resynchronization therapy (CRT) and arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) are presented. 相似文献
26.
Age-stiffening of ocular tissues is statistically linked to glaucoma in the elderly. In this study, the effects of age-stiffening on the lamina cribrosa, the primary site of glaucomatous nerve damages, were modeled using computational finite element analysis. We showed that glaucomatous nerve damages and peripheral vision loss behavior can be phenomenologically modeled by shear-based damage criterion. Using this damage criterion, the potential vision loss for 30 years old with mild hypertension of 25mmHg intraocular pressure (IOP) was estimated to be 4%. When the IOP was elevated to 35mmHg, the potential vision loss rose to 45%; and age-stiffening from 35 to 60 years old increased the potential vision loss to 52%. These results showed that while IOP plays a central role in glaucomatous damages, age-stiffening facilitates glaucomatous damages and may be the principal factor that resulted in a higher rate of glaucoma in the elderly than the general population. 相似文献
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Plant Molecular Biology - 相似文献
29.
T J Smith J S Lloyd S C Gallagher W L Fosdike J C Murrell H Dalton 《European journal of biochemistry》1999,260(2):446-452
Alkene monooxygenase (AMO) from Rhodococcus rhodochrous (formerly Nocardia corallina) B-276 is a three-component enzyme system encoded by the four-gene operon amoABCD. AMO catalyses the stereoselective epoxygenation of aliphatic alkenes, yielding primarily R enantiomers. The presumed site of alkene oxygenation is a dinuclear iron centre similar to that in the soluble methane monooxygenases of methanotrophic bacteria, to which AMO exhibits a significant degree of amino acid sequence identity. The AMO complex was not expressed in Escherichia coli, at least partly because that host did not produce all of the AMO polypeptides. Expression of AMO was achieved in Streptomyces lividans by cloning the AMO genes into the thiostrepton-inducible expression plasmid pIJ6021. No background of AMO activity was detected in S. lividans cells without amoABCD and expression of AMO activity, at a level comparable to that from wild-type R. rhodochrous B-276, coincided with appearance of the AMO subunits. Recombinant AMO activity in cell-free extracts of S. lividans was stimulated by the addition of NADH and produced R-epoxypropane with comparable enantiomeric excess to AMO purified from the original organism. Although the whole AMO complex could not be expressed in E. coli, the functional coupling protein (AmoB) and reductase (AmoD) were expressed individually in E. coli as fusions with glutathione S-transferase. The expression systems described here now allow structure/function studies on AMO to be carried out by site-directed mutagenesis. 相似文献
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