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241.
Penna ML 《Memórias do Instituto Oswaldo Cruz》2011,106(3):383-4; discussion 383-4
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Giannozzi P Jansen K La Penna G Minicozzi V Morante S Rossi G Stellato F 《Metallomics : integrated biometal science》2012,4(2):156-165
We show in this paper that in the presence of Zn ions a peculiar structural aggregation pattern of β-amyloid peptides in which metal ions are sequentially coordinated to either three or four histidines of nearby peptides is favored. To stabilize this configuration a deprotonated imidazole ring from one of the histidines forms a bridge connecting two adjacent Zn ions. Though present in zeolite imidazolate frameworks, remarkably in biological compounds this peculiar Zn-imidazolate-Zn topology is only found in enzymes belonging to the Cu,Zn-superoxide dismutase family in the form of an imidazolate bridging Cu and Zn. The results we present are obtained by combining X-ray absorption spectroscopy experimental data with detailed first-principle molecular dynamics simulations. 相似文献
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Leverrier S Bergamaschi D Ghali L Ola A Warnes G Akgül B Blight K García-Escudero R Penna A Eddaoudi A Storey A 《Apoptosis : an international journal on programmed cell death》2007,12(3):549-560
Apoptotic elimination of UV-damaged cells from the epidermis is an important step in preventing both the emergence and expansion
of cells with carcinogenic potential. A pivotal event in apoptosis is the release of apoptogenic factors from the mitochondria,
although the mechanisms by which the different proteins are released are not fully understood. Here we demonstrate that UV
radiation induced the mitochondrial to nuclear translocation of apoptosis inducing factor (AIF) in normal skin. The human
papillomavirus (HPV) E6 protein prevented release of AIF and other apoptotic factors such as cytochrome c and Omi from mitochondria of UV-damaged primary epidermal keratinocytes and preserved mitochondrial integrity. shRNA silencing
of Bak, a target for E6-mediated proteolysis, demonstrated the requirement of Bak for UV-induced AIF release and mitochondrial
fragmentation. Furthermore, screening non-melanoma skin cancer biopsies revealed an inverse correlation between HPV status
and AIF nuclear translocation. Our results indicate that the E6 activity towards Bak is a key factor that promotes survival
of HPV-infected cells that facilitates tumor development. 相似文献
246.
Maehr H Uskokovic M Adorini L Penna G Mariani R Panina P Passini N Bono E Perego S Biffi M Holick M Spina C Suh N 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):277-281
The searches for drugs that exhibit antineoplastic activity and regulate blood pressure are among the most prevalent and compelling research activities today. Amazingly, there is ample precedence for the antiproliferative action of vitamin-D-related compounds and their role as endocrine suppressors of renin biosynthesis. We have recently synthesized a number of novel calcitriol analogs of the gemini family and originally selected for further studies an epimeric pair related to 19-nor-calcitriol whose 21-methyl group was replaced by a 5,5,5-trifluoro-4-hydroxy-4-(trifluoromethyl)-2-pentynyl group. While maintaining the acceptable calcemic responses, the IC50 concentrations of interferon-γ release were reduced and the antiproliferative activity and inhibition of renin mRNA expression enhanced. Replacing the geminal methyl groups on the calcitriol-related side chain of these gemini compounds with trideuteriomethyl moieties further boosted the potency in the colon cancer model in mice some 10-fold, reduced NMU-induced breast cancer carcinogenesis in rats and decreased the IC50 values for renin mRNA inhibition into the pM range. 相似文献
247.
Nunzio Penna Samuela Capellacci Marco Giorgi Giorgio Famiglini Helga Trufelli 《Carbohydrate research》2009,344(1):120-40
The mucilage phenomenon, a sporadic but massive accumulation of gelatinous material, can cause serious damage to the tourism and fishing industries along the Adriatic coast. Mucilage is presently thought to be the result of the aggregation of dissolved organic matter (DOM) into particulate organic matter (POM). Three principal classes of compounds have been identified in organic matter by spectrometric determination: carbohydrates, proteins and lipids. Carbohydrates are suspected to play a role in the first steps of DOM aggregation. Despite its importance in understanding the processes leading to mucilage formation, our present knowledge of the composition of the mucilage carbohydrate fraction is incomplete. Due to its high sensitivity and specificity, liquid chromatography coupled with electrospray-ionization tandem mass spectrometry (LC-ESIMS/MS) is gaining an increasing importance as a powerful technique for carbohydrate purification and characterization in complex samples. In this work, LC-ESIMS/MS is proposed as a useful method for the investigation of the oligosaccharide content in mucilage samples. The approach was applied using 3-7 unit maltooligosaccharides as reference compounds. The composition of the investigated mucilage sample was further investigated combining LC-ESIMS/MS with classic approaches, such as spectroscopic techniques and liquid chromatography coupled with the refractory index LC-RI. 相似文献
248.
Andrea Bonetto Fabio Penna Maurizio Muscaritoli Valerio G. Minero Filippo Rossi Fanelli Francesco M. Baccino Paola Costelli 《Free radical biology & medicine》2009,47(7):906-916
Changes in the skeletal muscle protein mass frequently occur in both physiological and pathological states. Muscle hypotrophy, in particular, is commonly observed during aging and is characteristic of several pathological conditions such as neurological diseases, cancer, diabetes, and sepsis. The skeletal muscle protein content depends on the relative rates of synthesis and degradation, which must be coordinately regulated to maintain the equilibrium. Pathological muscle depletion is characterized by a negative nitrogen balance, which results from disruption of this equilibrium due to reduced synthesis, increased breakdown, or both. The current view, mainly based on experimental data, considers hypercatabolism as the major cause of muscle protein depletion. Several signaling pathways that probably contribute to muscle atrophy have been identified, and there is increasing evidence that oxidative stress, due to reactive oxygen species production overwhelming the intracellular antioxidant systems, plays a role in causing muscle depletion both during aging and in chronic pathological states. In particular, oxidative stress has been proposed to enhance protein breakdown, directly or by interacting with other factors. This review focuses on the possibility of using antioxidant treatments to target molecular pathways involved in the pathogenesis of skeletal muscle wasting. 相似文献
249.
Russo D Ottaggio L Penna I Foggetti G Fronza G Inga A Menichini P 《Biochemical and biophysical research communications》2010,402(2):345-350
PRIMA-1 has been identified as a compound that restores the transactivation function to mutant p53 and induces apoptosis in cells expressing mutant p53. Studies on subcellular distribution of the mutant p53 protein upon treatment with PRIMA-1Met, a methylated form of PRIMA-1, have suggested that redistribution of mutant p53 to nucleoli may play a role in PRIMA-1 induced apoptosis. Here, we specifically investigated the influence of PRIMA-1 on cellular localization of mutated p53-R280K endogenously expressed in tumour cells. By using immunofluorescence staining, we found a strong nucleolar redistribution of mutant p53 following PRIMA-1 treatment. This subcellular localization was associated to p53 degradation via ubiquitylation. When cells were treated with adriamycin, neither nucleolar redistribution nor mutant p53 down modulation and degradation were observed. Interestingly, cells where p53-R280K was silenced were more sensitive to PRIMA-1 than the parental ones. These results indicate that in some cellular context, the cell sensitivity to PRIMA-1 could depend on the abolition of a gain-of-function activity of the mutated p53, through a protein degradation pathway specifically induced by this compound. 相似文献
250.