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141.
Scapagnini G Vasto S Sonya V Abraham NG Nader AG Caruso C Calogero C Zella D Fabio G 《Molecular neurobiology》2011,44(2):192-201
In recent years, there has been a growing interest, supported by a large number of experimental and epidemiological studies,
for the beneficial effects of some phenolic substances, contained in commonly used spices and herbs, in preventing various
age-related pathologic conditions, ranging from cancer to neurodegenerative diseases. Although the exact mechanisms by which
polyphenols promote these effects remain to be elucidated, several reports have shown their ability to stimulate a general
xenobiotic response in the target cells, activating multiple defense genes. Data from our and other laboratories have previously
demonstrated that curcumin, the yellow pigment of curry, strongly induces heme-oxygenase-1 (HO-1) expression and activity
in different brain cells via the activation of heterodimers of NF-E2-related factors 2 (Nrf2)/antioxidant responsive element (ARE) pathway. Many studies clearly demonstrate that activation ofNrf2 target genes,
and particularly HO-1, in astrocytes and neurons is strongly protective against inflammation, oxidative damage, and cell death.
In the central nervous system, the HO system has been reported to be very active, and its modulation seems to play a crucial
role in the pathogenesis of neurodegenerative disorders. Recent and unpublished data from our group revealed that low concentrations
of epigallocatechin-3-gallate, the major green tea catechin, induces HO-1 by ARE/Nrf2 pathway in hippocampal neurons, and
by this induction, it is able to protect neurons against different models of oxidative damages. Furthermore, we have demonstrated
that other phenolics, such as caffeic acid phenethyl ester and ethyl ferulate, are also able to protect neurons via HO-1 induction.
These studies identify a novel class of compounds that could be used for therapeutic purposes as preventive agents against
cognitive decline. 相似文献
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In everyday life attention operates within complex and dynamic environments, while laboratory paradigms typically employ simple and stereotyped stimuli. This fMRI study investigated stimulus-driven spatial attention using a virtual-environment video. We explored the influence of bottom-up signals by computing saliency maps of the environment and by introducing attention-grabbing events in the video. We parameterized the efficacy of these signals for the orienting of spatial attention by measuring eye movements and used these parameters to analyze the imaging data. The efficacy of bottom-up signals modulated ongoing activity in dorsal fronto-parietal regions and transient activation of the ventral attention system. Our results demonstrate that the combination of computational, behavioral, and imaging techniques enables studying cognitive functions in ecologically valid contexts. We highlight the central role of the efficacy of stimulus-driven signals in both dorsal and ventral attention systems, with a dissociation of the efficacy of background salience versus distinctive events in the two systems. 相似文献
144.
Borcard F Godinat A Staedler D Blanco HC Dumont AL Chapuis-Bernasconi C Scaletta C Applegate LA Juillerat FK Gonzenbach UT Gerber-Lemaire S Juillerat-Jeanneret L 《Bioconjugate chemistry》2011,22(7):1422-1432
The chemical functionalization of cell-surface proteins of human primary fetal bone cells with hydrophilic bioorthogonal intermediates was investigated. Toward this goal, chemical pathways were developed for click reaction-mediated coupling of alkyne derivatives with cellular azido-expressing proteins. The incorporation via a tetraethylene glycol linker of a dipeptide and a reporter biotin allowed the proof of concept for the introduction of cell-specific peptide ligands and allowed us to follow the reaction in living cells. Tuning the conditions of the click reaction resulted in chemical functionalization of living human fetal osteoblasts with excellent cell survival. 相似文献
145.
Karen F Chambers Joanna F Pearson Davide Pellacani Naveed Aziz Miodrag Gužvić Christoph A Klein Shona H Lang 《Journal of biomedical science》2011,18(1):45
Background
Stromal signalling increases the lateral cell adhesions of prostate epithelial cells grown in 3D culture. The aim of this study was to use microarray analysis to identify significant epithelial signalling pathways and genes in this process. 相似文献146.
Pilak O Harrop SJ Siddiqui KS Chong K De Francisci D Burg D Williams TJ Cavicchioli R Curmi PM 《Environmental microbiology》2011,13(8):2232-2249
Archaea are abundant in permanently cold environments. The Antarctic methanogen, Methanococcoides burtonii, has proven an excellent model for studying molecular mechanisms of cold adaptation. Methanococcoides burtonii contains three group II chaperonins that diverged prior to its closest orthologues from mesophilic Methanosarcina spp. The relative abundance of the three chaperonins shows little dependence on organism growth temperature, except at the highest temperatures, where the most thermally stable chaperonin increases in abundance. In vitro and in vivo, the M. burtonii chaperonins are predominantly monomeric, with only 23-33% oligomeric, thereby differing from other archaea where an oligomeric ring form is dominant. The crystal structure of an N-terminally truncated chaperonin reveals a monomeric protein with a fully open nucleotide binding site. When compared with closed state group II chaperonin structures, a large-scale ≈ 30° rotation between the equatorial and intermediate domains is observed resulting in an open nucleotide binding site. This is analogous to the transition observed between open and closed states of group I chaperonins but contrasts with recent archaeal group II chaperonin open state ring structures. The predominance of monomeric form and the ability to adopt a fully open nucleotide site appear to be unique features of the M. burtonii group II chaperonins. 相似文献
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Cyclic AMP (cAMP) inhibits the proliferation of several tumor cells. We previously reported an antiproliferative effect of PKA I-selective cAMP analogs (8-PIP-cAMP and 8-HA-cAMP) on two human cancer cell lines of different origin. 8-Cl-cAMP, another cAMP analog with known antiproliferative properties, has been investigated as a potential anticancer drug. Here, we compared the antiproliferative effect of 8-Cl-cAMP and the PKA I-selective cAMP analogs in three human cancer cell lines (ARO, NPA and WRO). 8-Cl-cAMP and the PKA I-selective cAMP analogs had similarly potent antiproliferative effects on the BRAF-positive ARO and NPA cells, but not on the BRAF-negative WRO cells, in which only 8-Cl-cAMP consistently inhibited cell growth. While treatment with the PKA I-selective cAMP analogs was associated with growth arrest, 8-Cl-cAMP induced apoptosis. To further investigate the actions of 8-Cl-cAMP and the PKA I-selective cAMP analogs, we analyzed their effects on signaling pathways involved in cell proliferation and apoptosis. Interestingly, the PKA I-selective cAMP analogs, but not 8-Cl-cAMP, inhibited ERK phosphorylation, whereas 8-Cl-cAMP alone induced a progressive phosphorylation of the p38 mitogen-activated protein kinase (MAPK), via activation of AMPK by its metabolite 8-Cl-adenosine. Importantly, the pro-apoptotic effect of 8-Cl-cAMP could be largely prevented by pharmacological inhibition of the p38 MAPK. Altogether, these data suggest that 8-Cl-cAMP and the PKA I-selective cAMP analogs, though of comparable antiproliferative potency, act through different mechanisms. PKA I-selective cAMP analogs induce growth arrest in cells carrying the BRAF oncogene, whereas 8-Cl-cAMP induce apoptosis, apparently through activation of the p38 MAPK pathway. 相似文献