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991.
Diego La Mendola Serena Caminati Salvatore S. Emmi Giuseppe Maccarrone Adriana Pietropaolo 《Journal of inorganic biochemistry》2009,103(2):195-204
Potentiometric and spectroscopic (UV-Vis, CD and EPR) studies were carried out on copper(II) complexes with chicken prion protein N-terminal fragments, Ac-(PHNPGY)4-NH2, and the mutated residue, Ac-(PHNPGF)4-NH2, to assess the role of tyrosine in the copper coordination. Both thermodynamic and spectroscopic results indicate that chicken prion fragments are not able to bind more than two copper ions and only with the involvement of side chain tyrosine groups. The prevailing complex shows one copper ion bound to four imidazole nitrogen atoms in the 1:1 metal to ligand ratio systems. The superoxide dismutase (SOD)-like activity of copper(II) complexes with the avian peptides and mammal analogue, Ac-(PHGGGWGQ)4-NH2, was also investigated by means of Pulse radiolysis. The copper(II) complexes with avian peptides do not display SOD-like activity, while very low activity has been detected for the copper(II) complexes with mammalian tetraoctarepeat. 相似文献
992.
Attilio Pingitore Erika Cione Valentina Senatore Giuseppe Genchi 《Journal of bioenergetics and biomembranes》2009,41(3):215-221
This study was undertaken to better understand the physiological role of the retinoylation process in steroidogenic tissues.
In adrenal gland mitochondria, the retinoylation extent was found equal to that of testes mitochondria but without ATP in
the incubation buffer. We pointed out that the endogenous mitochondrial ATP in adrenal glands is much higher than in testes,
about 1.3 x 10−2 M and 5.2 x 10−8 M, respectively. In addition, less CoASH is required for the maximal acylation activity of the retinoyl moiety to protein(s)
compared to testes. The fatty acid analysis revealed a different composition of mitochondrial membranes of these two tissues.
Among the different values of fatty acids, it is important to note that adrenal glands contain a much higher amount of C18:0
and a much lower amount of C22:5 ω6 and C22:6 ω3 than testes in the mitochondrial membranes. In addition, there were also
differences in arachidonic acid (ARA, C20:4 ω6) content between adrenal glands and testes mitochondria. These different values
in the fatty acids composition should explain the different extent of the retinoylation process between the two organs. 相似文献
993.
Matt Smith Jean Emberlin Alicja Stach Auli Rantio-Lehtimäki Eric Caulton Michel Thibaudon Charlotte Sindt Siegfried Jäger Regula Gehrig Giuseppe Frenguelli Victoria Jato F. Javier Rodríguez Rajo Purificación Alcázar Carmen Galán 《Aerobiologia》2009,25(4):321-332
Relationships between temporal variations in the North Atlantic Oscillation (NAO) and grass pollen counts at 13 sites in Europe, ranging from Córdoba in the south-west and Turku in the north-east, were studied in order to determine spatial differences in the amount of influence exerted by the NAO on the timing and magnitude of grass pollen seasons. There were a number of significant (P < 0.05) relationships between the NAO and start dates of the grass pollen season at the 13 pollen-monitoring sites. The strongest associations were generally recorded near to the Atlantic coast. Several significant correlations also existed between winter averages of the NAO and grass pollen season severity. Traditional methods for predicting the start or magnitude of grass pollen seasons have centred on the use of local meteorological observations, but this study has shown the importance of considering large-scale patterns of climate variability like the NAO. 相似文献
994.
Stephanie L.H. Zeiger Erik S. Musiek Giuseppe Zanoni Giovanni Vidari Jason D. Morrow Ginger J. Milne BethAnn McLaughlin 《Free radical biology & medicine》2009,47(10):1422-1431
Stroke is the third leading cause of death in the United States, yet no neuroprotective agents for treatment are clinically available. There is a pressing need to understand the signaling molecules that mediate ischemic cell death and identify novel neuroprotective targets. Cyclopentenone isoprostanes (IsoPs), formed after free radical-mediated peroxidation of arachidonic acid, are used as markers of stress, but their bioactivity is poorly understood. We have recently shown that 15-A2t-IsoP is a potent neurotoxin in vitro and increases the free radical burden in neurons. In this work, we demonstrate that 15-A2t-IsoP is abundantly produced in stroke-infarcted human cortical tissue. Using primary neuronal cultures we found that minimally toxic exposure to 15-A2t-IsoP does not alter ATP content, but in combination with oxygen glucose deprivation resulted in a significant hyperpolarization of the mitochondrial membrane and dramatically increased neuronal cell death. In the presence of Ca2+, 15-A2t-IsoP led to a rapid induction of the permeability transition pore and release of cytochrome c. Taken with our previous work, these data support a model in which ischemia causes generation of reactive oxygen species, calcium influx, lipid peroxidation, and 15-A2t-IsoP formation. These factors combine to enhance opening of the permeability transition pore leading to cell death subsequent to mitochondrial cytochrome c release. These data are the first documentation of significant 15-A2t-IsoP formation after acute ischemic stroke and suggest that the addition of 15-A2t-IsoP to in vitro models of ischemia may help to more fully recapitulate stroke injury. 相似文献
995.
Anthony Makkinje Richard I. Near Giuseppe Infusini Pierre Vanden Borre Alexander Bloom Dongpo Cai Catherine E. Costello Adam Lerner 《Cellular signalling》2009,21(9):1423-1435
NSP protein family members associate with p130Cas, a focal adhesion adapter protein best known as a Src substrate that integrates adhesion-related signaling. Over-expression of AND-34/BCAR3/NSP2 (BCAR3), but not NSP1 or NSP3, induces anti-estrogen resistance in human breast cancer cell lines. BCAR3 over-expression in epithelial MCF-7 cells augments levels of a phosphorylated p130Cas species that migrates more slowly on SDS-PAGE while NSP1 and NSP3 induce modest or no phosphorylation, respectively. Conversely, reduction in BCAR3 expression in mesenchymal MDA-231 cells by inducible shRNA results in loss of such p130Cas phosphorylation. Replacement of NSP3's serine/proline-rich domain with that of AND-34/BCAR3 instills the ability to induce p130Cas phosphorylation. Phospho-amino acid analysis demonstrates that BCAR3 induces p130Cas serine phosphorylation. Mass spectrometry identified phosphorylation at p130Cas serines 139, 437 and 639. p130Cas serine phosphorylation accumulates for several hours after adhesion of MDA-231 cells to fibronectin and is dependent upon BCAR3 expression. BCAR3 knockdown alters p130Cas localization and converts MDA-231 growth to an epithelioid pattern characterized by striking cohesiveness and lack of cellular projections at colony borders. These studies demonstrate that BCAR3 regulates p130Cas serine phosphorylation that is adhesion-dependent, temporally distinct from previously well-characterized rapid Fak and Src kinase-mediated p130Cas tyrosine phosphorylation and that correlates with invasive phenotype. 相似文献
996.
Laura Carsetti Luca Laurenti Stefania Gobessi Pablo G. Longo Giuseppe Leone Dimitar G. Efremov 《Cellular signalling》2009,21(7):1187-1194
The Syk kinase is regarded as a promising target for the treatment of antigen-driven B-cell malignancies, considering its essential role in propagating antigenic stimuli through the B-cell receptor (BCR). In certain common B-cell malignancies Syk is activated even in the absence of BCR engagement, suggesting a wider role for this kinase in lymphomagenesis. In this paper, we have profiled molecular differences between BCR-induced and constitutive Syk activation in terms of phosphorylation of regulatory tyrosine residues, downstream signaling properties and capacity to sustain B-cell proliferation. Analysis of primary chronic lymphocytic leukemia B-cells and diffuse large B-cell lymphoma cell lines revealed that constitutive and BCR-induced Syk activation differ with respect to the phosphorylation status of the regulatory tyrosines at positions 352 and 525/526, with only the first site being phosphorylated in the case of constitutive and both sites in the case of BCR-induced Syk activation. Syk phosphorylated only on Y352 is capable of downstream signaling, as evidenced by experiments with a phosphomimetic mutant in which the activation loop tyrosines (YY525/526) were replaced with phenylalanines. However, phosphorylation at YY525/526 was shown to significantly increase the enzymatic activity of Syk and to be required for sustained PLCγ2, Akt and ERK signaling as well as B-cell transformation. These data demonstrate that constitutively active Syk and Syk activated by BCR crosslinking represent separate stages of Syk activation with distinct signaling properties and transforming capacities. 相似文献
997.
Ursino M Cuppini C Magosso E Serino A di Pellegrino G 《Journal of computational neuroscience》2009,26(1):55-73
Neurons in the superior colliculus (SC) are known to integrate stimuli of different modalities (e.g., visual and auditory)
following specific properties. In this work, we present a mathematical model of the integrative response of SC neurons, in
order to suggest a possible physiological mechanism underlying multisensory integration in SC. The model includes three distinct
neural areas: two unimodal areas (auditory and visual) are devoted to a topological representation of external stimuli, and
communicate via synaptic connections with a third downstream area (in the SC) responsible for multisensory integration. The
present simulations show that the model, with a single set of parameters, can mimic various responses to different combinations
of external stimuli including the inverse effectiveness, both in terms of multisensory enhancement and contrast, the existence
of within- and cross-modality suppression between spatially disparate stimuli, a reduction of network settling time in response
to cross-modal stimuli compared with individual stimuli. The model suggests that non-linearities in neural responses and synaptic
(excitatory and inhibitory) connections can explain several aspects of multisensory integration. 相似文献
998.
Caccamo D Di Mauro D Condello S Currò M Cutroneo G Anastasi GP Ientile R Trimarchi F 《Amino acids》2009,36(1):49-56
Several studies demonstrated that transglutaminases play a key role in extracellular matrix stabilization needed for cell
differentiation. We evaluated transglutaminase expression and activity in the pre-secretory stage of differentiation of the
continuously erupting rat incisor. We observed that transglutaminase-mediated incorporation of monodansylcadaverine into protein
substrates was specifically located in the apical loop, and along the basement membrane joining mesenchyme and inner dental
epithelium in the odontogenic organ. Enzyme activity was associated with mRNAs for transglutaminase 1 and 2. Notably, labelling
cells for these isoenzymes were observed in both mesenchymal and epithelial compartments, but not in the basement membrane,
in the ameloblast facing pulp anterior region, where ameloblast and odontoblast differentiation begins. These findings demonstrate
that transglutaminase 1 and transglutaminase 2 are expressed at a major extent in the pre-secretory stage of regenerating
rat incisor, where they probably play complementary roles in cell signalling between mesenchyme and epithelium and extracellular
matrix. 相似文献
999.
Giuseppe Puddu Luigi Maiorano Alessandra Falcucci Fabio Corsi Luigi Boitani 《Biodiversity and Conservation》2009,18(8):2001-2016
The Corsican red deer, a sub-species of the European red deer endemic to Sardinia and Corsica, was abundant on both islands
at the beginning of 1900. It went extinct in Corsica and reached a minimum of 100 individuals in Sardinia by 1970. Numbers
have recovered in Sardinia with more than 1,000 rutting males now present; in the 1980s the deer was reintroduced to Corsica,
but the Sardinian population remains fragmented. We developed a potential distribution model in Sardinia using Ecological
Niche Factor Analysis. To assess the deer’s protection status we compared the model with the existing and proposed conservation
areas and investigated different conservation scenarios in relation to the expansion of its current range and resilience to
future changes in land use and predicted trends of desertification. According to our results over 70% of Sardinia is unsuitable
to the deer, nevertheless high suitability areas (Mediterranean forests away from main roads) are available throughout the
island, particularly in the south and in the central-eastern part. Existing protected areas do not provide for the conservation
of the deer but public owned forests, where hunting is prohibited, extend some level of protection, and the protected areas
proposed by the Regional administration, if implemented, will be increasing this protection. Three main areas have emerged
as conservation priorities to guarantee adequate conservation potential in the future. Our approach provides valuable data
to inform conservation policy, and could be easily replicated in other parts of the Mediterranean. 相似文献