Latest PUBLICATIONS

  • Neurogenesis in adult CNS: from denial to opportunities and challenges for therapy.
    Publication Date: 01/02/2008, on BioEssays : news and reviews in molecular, cellular and developmental biology
    by Colucci-D'Amato L, di Porzio U
    DOI: 10.1002/bies.20703

    The discovery of neurogenesis and neural stem cells (NSC) in the adult CNS has overturned a long-standing and deep-routed "dogma" in neuroscience, established at the beginning of the 20(th) century. This dogma lasted for almost 90 years and died hard when NSC were finally isolated from the adult mouse brain. The scepticism in accepting adult neurogenesis has now turned into a rush to find applications to alleviate or cure the devastating diseases that affect the CNS. Here we highlight a number of methodological, technical and conceptual drawbacks responsible for the historical denial of adult neurogenesis. Furthermore, we discuss old and new issues that need to be faced before NSC or endogenous neurogenesis can safely enter into the doctor's bag for therapies.

  • Effect of low doses of red wine and pure resveratrol on circulating endothelial progenitor cells.
    Publication Date: 01/02/2008, on Journal of biochemistry
    by Balestrieri ML, Schiano C, Felice F, Casamassimi A, Balestrieri A, Milone L, Servillo L, Napoli C
    DOI: 10.1093/jb/mvm209

    Circulating endothelial progenitor cells (EPCs) play a significant role in neovascularization of ischaemic tissues and in re-endothelization of injured blood vessels. Identification of compounds able to enhance EPC levels and improve their functional activity, noticeably compromised by risk factors for coronary heart disease, is of clinical interest. This study evaluates the effects of red wine on EPCs. After being isolated from total peripheral blood mononuclear cells, EPC phenotype was confirmed by the presence of double positive cells for DiLDL uptake and lectin binding and by expression of CD34, CD133 and VE-cadherin cell surface markers. Long-term culture in the presence of red wine (1 microl/ml), containing resveratrol (Resv) at physiological concentration (nM), determined a time-dependent amelioration of cell number (P < 0.05). The presence of red wine prevented the TNF-alpha-induced reduction of EPC number (P < 0.05) and this effect was accompanied by reduced p38-phosphorylation expression levels (P < 0.05) and increased NOx levels (P < 0.05) Indeed, pure Resv alone significantly improved the TNF-alpha reduced EPC number (P < 0.05). This evidence indicates novel beneficial effects of red wine and Resv in the positive modulation of EPCs levels.

  • Resveratrol-induced apoptosis depends on the lipid kinase activity of Vps34 and on the formation of autophagolysosomes.
    Publication Date: 01/02/2008, on Carcinogenesis
    by Trincheri NF, Follo C, Nicotra G, Peracchio C, Castino R, Isidoro C
    DOI: 10.1093/carcin/bgm271

    In human colorectal DLD1 cancer cells, the dietary bioflavonoid resveratrol (RV) rapidly induced autophagy. This effect was reversible (on removal of the drug) and was associated with increased expression and cytosolic redistribution of the proteins Beclin1 and LC3 II. Supplementing the cells with asparagine (Asn) abrogated the Beclin-dependent autophagy. When applied acutely (2 h), RV was not toxic; however, reiterate chronic (48 h) exposure to RV eventually led to annexin V- and terminal deoxinucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cell death. This toxic effect was autophagy dependent, as it was prevented either by Asn, by expressing a dominant-negative lipid kinase-deficient class III phosphoinositide 3-phosphate kinase, or by RNA interference knockdown of Beclin1. Lamp2b silencing abolished the fusion of autophagosomes with lysosomes and preserved cell viability despite the ongoing formation of autophagosomes in cells chronically exposed to RV. The pan-caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone inhibited RV-induced cell death, but not autophagy. These results uncover a novel pathway of RV cytotoxicity in which autophagy plays a dual role: (i) at first, it acts as a prosurvival stress response and (ii) at a later time, it switches to a caspase-dependent apoptosis pathway. The present data also indicate that genetic or epigenetic inactivation of autophagy proteins in cancer cells may confer resistance to RV-mediated killing.

  • A fast and simple method for simultaneous mixed site-specific mutagenesis of a wide coding sequence.
    Publication Date: 01/02/2008, on Biotechnology and applied biochemistry
    by Follo C, Isidoro C
    DOI: 10.1042/BA20070045

    Site-specific mutagenesis at one or multiple sites has recently become an invaluable strategy in functional proteomic studies and genetic engineering.

  • Infratentorial progressive multifocal leukoencephalopathy in a patient treated with fludarabine and rituximab.
    Publication Date: 01/02/2008, on Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology
    by Bonavita S, Conforti R, Russo A, Sacco R, Tessitore A, Gallo A, Della Corte M, Monsurrò MR, Tedeschi G
    DOI: 10.1007/s10072-008-0857-x

    Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease of the central nervous system caused by the JC papovavirus, and is a well known complication in patients with lymphoproliferative diseases (LPDs) during chemotherapy. We report the case of a 59-year-old woman affected by B-cell LPD who underwent three cycles of chemotherapy with fludarabine and rituximab and developed atypical PML six months after the last cycle of chemotherapy. Our patient showed the following peculiarities: chemotherapy regimen was neither heavy nor prolonged; the onset of neurological symptoms was unexpectedly late; the MRI lesion was atypical for non-HIV-related PML, being monofocal and infratentorial with early gadolinium (Gd) enhancement and mass effect; survival was rather prolonged despite the lack of treatment. These data suggest that in patients with LPDs, the occurrence of progressive neurological deficits should induce the suspicion of PML even when clinical onset is late (with respect to chemotherapy) and in the presence of a single infratentorial lesion, with Gd enhancement and mass effect.

  • Stability and binding properties of a modified thrombin binding aptamer.
    Publication Date: 15/01/2008, on Biophysical journal
    by Pagano B, Martino L, Randazzo A, Giancola C
    DOI: 10.1529/biophysj.107.117382

    Aptamer-based drugs represent an attractive approach in pharmacological therapy. The most studied aptamer, thrombin binding aptamer (TBA), folds into a well-defined quadruplex structure and binds to its target with good specificity and affinity. Modified aptamers with improved biophysical properties could constitute a new class of therapeutic aptamers. In this study we show that the modified thrombin binding aptamer (mTBA), (3')GGT(5')-(5')TGGTGTGGTTGG(3'), which also folds into a quadruplex structure, is more stable than its unmodified counterpart and shows a higher thrombin affinity. The stability of the modified aptamer was investigated using differential scanning calorimetry, and the energetics of mTBA and TBA binding to thrombin was characterized by means of isothermal titration calorimetry (ITC). ITC data revealed that TBA/thrombin and mTBA/thrombin binding stoichiometry is 1:2 for both interactions. Structural models of the two complexes of thrombin with TBA and with mTBA were also obtained and subjected to molecular dynamics simulations in explicit water. Analysis of the models led to an improvement of the understanding of the aptamer-thrombin recognition at a molecular level.

  • A rapid and selective mass spectrometric method for the identification of nitrated proteins.
    Publication Date: 01/01/2008, on Methods in molecular biology (Clifton, N.J.)
    by Amoresano A, Chiappetta G, Pucci P, Marino G
    DOI: 10.1007/978-1-60327-517-0_2

    The nitration of protein tyrosine residues represents an important posttranslational modification during development, oxidative stress, and biological aging. The major challenge in the proteomic analysis of nitroproteins is the need to discriminate modified proteins, usually occurring at substoichiometric levels, from the large amount of nonmodified proteins. Moreover, precise localization of the nitration site is often required to fully describe the biological process. Identification of the specific targets of protein oxidation was previously accomplished using immunoprecipitation techniques followed by immunochemical detection. Here, we report a totally new approach involving dansyl chloride labeling of the nitration sites which relies on the enormous potential of MS(n) analysis. The tryptic digest from the entire protein mixture is directly analyzed by MS on a linear ion trap mass spectrometer. Discrimination between nitro- and unmodified peptide is based on two selectivity criteria obtained by combining a precursor ion scan and a MS3 analysis. The novel labeling procedure was successfully applied to the identification of 3-nitrotyrosine residues in complex protein mixtures.

  • Rehabilitation of gesture imitation: a case study with fMRI.
    Publication Date: 01/01/2008, on Neurocase
    by Barbarulo AM, Pappatà S, Puoti G, Prinster A, Grossi D, Cotrufo R, Salvatore M, Trojano L
    DOI: 10.1080/13554790802363688

    Acquired disorders of gesture imitation are amenable to treatment, but with poor generalisation toward gestures not included in the training program. We investigated the neural basis of this item-specific recovery in a patient with a slowly progressive posterior cortical atrophy, by means of an fMRI study comparing imitation of rehabilitated and not-rehabilitated gestures. Results suggested that in our patient gesture imitation recruited the mirror system and additional areas relevant to gesture analysis and preparation. Imitation of rehabilitated gestures activated the mirror neuron system, and also left dorsolateral prefrontal cortex and putamen, and the right anterior temporal cortex. This suggests that item-specific recovery was based on interaction of circuitry of imitation with neural systems involved in emotional and motivational processing.

  • Visuospatial and visuoconstructive deficits.
    Publication Date: 01/01/2008, on Handbook of clinical neurology
    by Trojano L, Conson M
    DOI: 10.1016/S0072-9752(07)88019-5

  • Crown ether ring-fused nucleosides: synthesis and conformational properties.
    Publication Date: 01/01/2008, on Nucleic acids symposium series (2004)
    by Coppola C, D'Onofrio J, Di Fabio G, De Napoli L, Montesarchio D
    DOI: 10.1093/nass/nrn337

    We here describe the synthesis of a series of novel bicyclic ribonucleoside derivatives, with 18-crown-6 ether moieties attached via their ribose 2- and 3- positions, as first examples of crown ether ring-fused nucleosides, to be evaluated as antiviral and/or antitumoral agents.

  • A versatile synthetic approach for the development of libraries of 5', 3'-bis-conjugated oligonucleotides.
    Publication Date: 01/01/2008, on Nucleic acids symposium series (2004)
    by Di Fabio G, Coppola C, D'Onofrio J, De Napoli L, Montesarchio D
    DOI: 10.1093/nass/nrn151

    A versatile approach to develop libraries of diverse 5',3'-bis-conjugated oligonucleotides (ODNs) is here described. The usage of ad hoc derivatized solid supports, to which the first nucleoside unit is attached through a phosphate linkage, opens easy synthetic access to a large variety of hybrid bis-conjugated oligomers. The G-quadruplex forming d((5')TGGGAG(3')) sequence, as a potential anti-HIV agent, has been here used as a model system.

  • G-quadruplex forming oligonucleotides as finely tunable aptamers: towards better DNA mimics.
    Publication Date: 01/01/2008, on Nucleic acids symposium series (2004)
    by Montesarchio D
    DOI: 10.1093/nass/nrn005

    The intense search for oligonucleotides (ODNs) endowed with pharmacological activities has led, in the past decade, to the identification of tens of candidate drugs, now being evaluated in preclinical or clinical trials. Based on G-rich DNA sequences, several aptamers, adopting G-quadruplex structures with different topologies, have been selected as potent in vitro antiviral and/or antitumoral agents. In order to develop novel therapeutically relevant G-quadruplex-based aptamers, we have investigated - as a model compound - the (5')d(TGGGAG)(3') sequence, known to be anti-HIV-1 active if 5'-modified with bulky aromatic residues. A set of 5'-conjugated analogues has been analyzed by integrated CD, DSC and molecular modelling studies, allowing a detailed biophysical characterization of the resulting G-quadruplexes. Following the assumption that the kinetically and thermodynamically favoured formation of the quadruplex complexes is a pre-requisite for their efficient antiviral activity, novel hybrid ODNs, carrying diverse terminal modifications, were prepared via a fully automated, on-line phosphoramidite-based strategy and evaluated for anti-HIV activity.

  • Proteomics and cardiovascular disease: an update.
    Publication Date: 01/01/2008, on Current medicinal chemistry
    by Balestrieri ML, Giovane A, Mancini FP, Napoli C
    DOI:

    Proteomics has unraveled important questions in the biology of cardiovascular disease and holds even greater promise for the development of novel diagnostic and prognostic biomarkers. This approach may establish early detection strategies, and monitor responses to therapies. Technological advances (most notably blue native polyacrylamide gel electrophoresis, electrospray ionization, matrix-assisted laser desorption/ionization (MALDI), analysis of MALDI-derived peptides in Time-of-Flight (TOF) analyzers, and multidimensional protein identification technology (MudPIT) and bioinformatics for data handling and interpretation allow a large-scale identification of peptide sequence and post-translational modifications. Moreover, combination of proteomic biomarkers with clinical phenotype, metabolite changes, and genetic haplotype information is promising for the physician assessment of individual cardiovascular risk profile.

  • Natural computing and biological evolution: a new paradigm.
    Publication Date: 01/01/2008, on Rivista di biologia
    by Giuditta A
    DOI:

    After a brief outline of the available hypotheses on the mechanism of biological evolution, attention is called on the global nature of the variations leading to the generation of new species. Integrated changes may hardly be attributed to beneficial random mutations of single traits even if assisted by a phylogenetic elimination of poorly adapted individuals. Rather, integrated variations are likely to reflect the outcome of cybernetic algorithms (natural computing) operating on organism's resources and impending environmental changes. As all organisms are endowed with computing capacities that modulate and integrate ontogenetic development and maintenance of biological functions, structures, and behaviors, these capacities are assumed to have moulded the evolutionary variations of organisms, and their transfer to the progeny.

  • Hb Foggia or alpha 117(GH5)Phe -&gt; Ser: a new alpha 2 globin allele affecting the alpha Hb-AHSP interaction.
    Publication Date: 01/01/2008, on Haematologica
    by Lacerra G, Scarano C, Musollino G, Flagiello A, Pucci P, Carestia C
    DOI: 10.3324/haematol.11789

    We report a novel alpha2-globin gene allele with the mutation cod 117 TTC>TCC or alpha 117(GH5)Phe>Ser detected in three carriers with alpha-thalassemia phenotype. The mutated mRNA was present in the reticulocytes in the same amount as the normal one, but no chain or hemoglobin variant were detected. Most likely the amino acid substitution impairs the interaction of the alpha-chain variant with the AHSP and prevents its stabilizing effect, thus leading to the alpha-chain pool reduction.