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991.
The eukaryotic spindle assembly checkpoint (SAC) delays anaphase in the presence of chromosome attachment errors. Bub3 has been reported to be required for SAC activity in all eukaryotes examined so far. We find that Bub3, unlike its binding partner Bub1, is not essential for the SAC in fission yeast. As Bub3 is needed for the efficient kinetochore localization of Bub1, and of Mad1, Mad2 and Mad3, this implies that most SAC proteins do not need to be enriched at the kinetochores for the SAC to function. We find that Bub3 is also dispensable for shugoshin localization to the centromeres, which is the second known function of Bub1. Instead, Bub3, together with Bub1, has a specific function in promoting the conversion from chromosome mono‐orientation to bi‐orientation. 相似文献
992.
Anna Di Vito Maria Mele Antonella Piscioneri Sabrina Morelli Loredana De Bartolo Tullio Barni Rosa Maria Facciolo Marcello Canonaco 《Cellular and molecular neurobiology》2014,34(4):501-509
It’s known that neurons in mammalian hibernators are more tolerant to hypoxia than those in non-hibernating species and as a consequence animals are capable of awakening from the arousal state without exhibiting cerebral damages. In addition, evidences have suggested that euthermic hamster neurons display protective adaptations against hypoxia, while those of rats are not capable, even though molecular mechanisms involved in similar neuroprotective strategies have not been yet fully studied. In the present work, overstimulation of glutamatergic receptors NMDA recognized as one of the major death-promoting element in hypoxia, accounted for altered network complexity consistent with a moderate reduction of hippocampal neuronal survival (p < 0.05) in hamsters. These alterations appeared to be featured concomitantly with altered glutamatergic signaling as indicated by significant down-regulation (p < 0.01) of NMDAergic (NR2A) and AMPAergic (GluR1, R2) receptor subtypes together with the metabotropic mGluR5 subtype. Diminished mRNA levels were also reported for NMDA receptor binding factors and namely PSD95 plus DREAM, which exert positive and negative regulatory properties, respectively, on receptor trafficking events. Conversely, involvement of glutamatergic signaling systems on neuronal excitotoxicity was strengthened by the co-activation of GABAAR-mediated effects as indicated by toxic morphological effects being notably reduced along with up-regulated GluR1, GluR2, mGluR5, DREAM, and Homer1c scaffold proteins when muscimol was added. Overall, these results point to a neuroprotective role of the GABAergic system against excitotoxicity episodes via DREAM-dependent inhibition of NMDA receptor and activation of AMPA receptor plus mGluR5, respectively, thus proposing them as novel therapeutic targets against cerebral ischemic damages in humans. 相似文献
993.
Antonio Fiorentino Brigida D'Abrosca Assunta Esposito Angelina Izzo Maria Teresa Pascarella Grazia D'Angelo Pietro Monaco 《Biochemical Systematics and Ecology》2009,37(4):349-353
The allelopathic effects of neo-clerodane diterpenes, isolated from Teucrium chamaedrys (L.), have been evaluated on the seed germination and seedling growth of four coexisting Mediterranean species (Dactylis hispanica, Petrorhagia velutina, Phleum subulatum and Petrorhagia saxifraga) and two cosmopolitan weeds (Amaranthus retroflexus and Avena fatua). All of the structures have been elucidated on the basis of their spectroscopic features. The bioassays data, analyzed by principal component analysis, showed more negative effects on weeds respect to coexisting species. Moreover D. hispanica, P. velutina, P. subulatum showed both stimulating or inhibiting effects depending on the type of metabolite and the concentration used in the test. 相似文献
994.
Cristiane Pilisso Patrícia de Oliveira Carvalho Maria da Graa Nascimento 《Process Biochemistry》2009,44(12):1352-1357
The enzymatic acylation of (RS)-phenylethylamine with different acyl donors catalysed by lipases, was studied in organic solvents with different hydrophobicities and in mixtures with ionic liquids ((ILs); [BMIm][BF4], [BMIm][SCN], [BMIm][Cl] and [BMIm][PF6]). Using lipases from Candida antarctica B (CAL-B) and from Aspergillus niger higher conversion degrees and E-values were obtained with ethyl acetate as the acyl donor. When CAL-B was used as the biocatalyst, in a two-phase system formed by [BMIm][X]/dichloromethane or [BMIm][X]/chloroform, the selectivity was better than that obtained in pure organic solvents. The selectivity was found to be related to individual anions in ILs. In this reaction, the ion effectiveness in enhancing the enzyme selectivity followed the series: Cl− > SCN− > BF4− > PF6− in mixtures with dichloromethane, and PF6− > BF4− > SCN− > Cl− in mixtures with chloroform. 相似文献
995.
996.
Pereira RP Fachinetto R de Souza Prestes A Puntel RL Santos da Silva GN Heinzmann BM Boschetti TK Athayde ML Bürger ME Morel AF Morsch VM Rocha JB 《Neurochemical research》2009,34(5):973-983
Considering the important role of oxidative stress in the pathogenesis of several neurological diseases, and the growing evidence
of the presence of compounds with antioxidant properties in the plant extracts, the aim of the present study was to investigate
the antioxidant capacity of three plants used in Brazil to treat neurological disorders: Melissa officinalis, Matricaria recutita and Cymbopogon citratus. The antioxidant effect of phenolic compounds commonly found in plant extracts, namely, quercetin, gallic acid, quercitrin
and rutin was also examined for comparative purposes. Cerebral lipid peroxidation (assessed by TBARS) was induced by iron
sulfate (10 μM), sodium nitroprusside (5 μM) or 3-nitropropionic acid (2 mM). Free radical scavenger properties and the chemical
composition of plant extracts were assessed by 1′-1′ Diphenyl-2′ picrylhydrazyl (DPPH) method and by Thin Layer Chromatography
(TLC), respectively. M. officinalis aqueous extract caused the highest decrease in TBARS production induced by all tested pro-oxidants. In the DPPH assay, M. officinalis presented also the best antioxidant effect, but, in this case, the antioxidant potencies were similar for the aqueous, methanolic
and ethanolic extracts. Among the purified compounds, quercetin had the highest antioxidant activity followed by gallic acid,
quercitrin and rutin. In this work, we have demonstrated that the plant extracts could protect against oxidative damage induced
by various pro-oxidant agents that induce lipid peroxidation by different process. Thus, plant extracts could inhibit the
generation of early chemical reactive species that subsequently initiate lipid peroxidation or, alternatively, they could
block a common final pathway in the process of polyunsaturated fatty acids peroxidation. Our study indicates that M. officinalis could be considered an effective agent in the prevention of various neurological diseases associated with oxidative stress. 相似文献
997.
Rosa Luisi Elisabetta Panza Vincenzo Barrese Fabio Arturo Iannotti† Davide Viggiano† Agnese Secondo Lorella Maria Teresa Canzoniero Maria Martire‡ Lucio Annunziato Maurizio Taglialatela† 《Journal of neurochemistry》2009,109(1):168-181
In this study, the functional consequences of the pharmacological modulation of the M‐current (IKM) on cytoplasmic Ca2+ intracellular Ca2+concentration ([Ca2+]i) changes and excitatory neurotransmitter release triggered by various stimuli from isolated rat cortical synaptosomes have been investigated. Kv7.2 immunoreactivity was identified in pre‐synaptic elements in cortical slices and isolated glutamatergic cortical synaptosomes. In cerebrocortical synaptosomes exposed to 20 mM [K+]e, the IKM activator retigabine (RT, 10 μM) inhibited [3H]d ‐aspartate ([3H]d ‐Asp) release and caused membrane hyperpolarization; both these effects were prevented by the IKM blocker XE‐991 (20 μM). The IKM activators RT (0.1–30 μM), flupirtine (10 μM) and BMS‐204352 (10 μM) inhibited 20 mM [K+]e‐induced synaptosomal [Ca2+]i increases; XE‐991 (20 μM) abolished RT‐induced inhibition of depolarization‐triggered [Ca2+]i transients. The P/Q‐type voltage‐sensitive Ca2+channel (VSCC) blocker ω‐agatoxin IVA prevented RT‐induced inhibition of depolarization‐induced [Ca2+]i increase and [3H]d ‐Asp release, whereas the N‐type blocker ω‐conotoxin GVIA failed to do so. Finally, 10 μM RT did not modify the increase of [Ca2+]i and the resulting enhancement of [3H]d ‐Asp release induced by [Ca2+]i mobilization from intracellular stores, or by store‐operated Ca2+channel activation. Collectively, the present data reveal that the pharmacological activation of IKM regulates depolarization‐induced [3H]d ‐Asp release from cerebrocortical synaptosomes by selectively controlling the changes of [Ca2+]i occurring through P/Q‐type VSCCs. 相似文献
998.
Cristiana Pistol Tanase Simona Dima Mihaela Mihai Elena Raducan Mihnea Ioan Nicolescu Lucian Albulescu Bogdan Voiculescu Traian Dumitrascu Linda Maria Cruceru Mircea Leabu Irinel Popescu Mihail Eugen Hinescu 《Journal of molecular histology》2009,40(1):23-29
The assessment of caveolin-1 (Cav-1) as a marker of tumor aggressiveness in pancreatic ductal adenocarcinoma (PDAC). In this
study, we examined the expression of Cav-1 in 34 human PDAC tissue samples and the associated peritumoral tissues by immunohistochemistry
and western blot. Additionally, we correlated Cav-1 expression with other tissue (Ki-67, p53) and serum (CA 19-9) tumor markers.
In the tumor-derived tissue, both tumor cells and blood vessels expressed Cav-1. In contrast, in peritumoral tissue, Cav-1
expression was confined mainly to blood vessels and was only occasionally expressed in ductal or parenchymal cells. Western
blot analysis confirmed the overexpression of Cav-1 in pancreatic tumors compared with peritumoral tissue. Cav-1 expression
in tumor tissues was correlated with both the Ki-67 LI (r = 0.95, P < 0.0001) and p53 expression (χ2 = 9.91, P < 0.005). Overexpression of Cav-1 was associated with tumor size, grade and stage and Cav-1 expression in tumors was correlated
with an increased serum level of CA 19-9 (r = 0.795, P < 0.001). Based on the results of this study, the inclusion of Cav-1 in a putative panel of biomarkers predicting pancreatic
cancer aggressiveness is warranted. 相似文献
999.
Michaela Zumtobel Ojan Assadian Matthias Leonhard Maria Stadler Berit Schneider 《BMC microbiology》2009,9(1):150-4