Latest PUBLICATIONS

  • Independent component model of the default-mode brain function: combining individual-level and population-level analyses in resting-state fMRI.
    Publication Date: 01/09/2008, on Magnetic resonance imaging
    by Esposito F, Aragri A, Pesaresi I, Cirillo S, Tedeschi G, Marciano E, Goebel R, Di Salle F
    DOI: 10.1016/j.mri.2008.01.045

    Resting-state functional magnetic resonance imaging (RS-fMRI) is a technique used to investigate the spontaneous correlations of blood-oxygen-level-dependent signals across different regions of the brain. Using functional connectivity tools, it is possible to investigate a specific RS-fMRI network, referred to as "default-mode" (DM) network, that involves cortical regions deactivated in fMRI experiments with cognitive tasks. Previous works have reported a significant effect of aging on DM regions activity. Independent component analysis (ICA) is often used for generating spatially distributed DM functional connectivity patterns from RS-fMRI data without the need for a reference region. This aspect and the relatively easy setup of an RS-fMRI experiment even in clinical trials have boosted the combined use of RS-fMRI and ICA-based DM analysis for noninvasive research of brain disorders. In this work, we considered different strategies for combining ICA results from individual-level and population-level analyses and used them to evaluate and predict the effect of aging on the DM component. Using RS-fMRI data from 20 normal subjects and a previously developed group-level ICA methodology, we generated group DM maps and showed that the overall ICA-DM connectivity is negatively correlated with age. A negative correlation of the ICA voxel weights with age existed in all DM regions at a variable degree. As an alternative approach, we generated a distributed DM spatial template and evaluated the correlation of each individual DM component fit to this template with age. Using a "leave-one-out" procedure, we discuss the importance of removing the bias from the DM template-generation process.

  • Glycolipids from sponges. 20. J-Coupling analysis for stereochemical assignments in furanosides: structure elucidation of vesparioside B, a glycosphingolipid from the marine sponge Spheciospongia vesparia.
    Publication Date: 15/08/2008, on The Journal of organic chemistry
    by Costantino V, Fattorusso E, Imperatore C, Mangoni A
    DOI: 10.1021/jo800837k

    Reinvestigation of the glycosphingolipid composition of the marine sponge Spheciospongia vesparia revealed the presence of vesparioside B ( 2a), a new furanose-rich hexaglycosylated glycosphingolipid that is the most complex glycosphingolipid isolated from a marine sponge to date. The structure of the new compound was elucidated using extensive 2D NMR studies and chemical degradation. Particularly useful for structure elucidation of vesparioside B was a quantum mechanical computational study, showing that in furanosides a vicinal coupling constant <2.0 Hz (for H-1/H-2 or H-3/H-4) or <3.5 Hz (for H-2/H-3) is a proof of the trans orientation of the relevant protons. This general rule, combined with ROE data, allowed us to elucidate the relative stereochemistry (including anomeric configuration) of the three furanose five-membered rings.

  • Antioxidants increase number of progenitor endothelial cells through multiple gene expression pathways.
    Publication Date: 01/08/2008, on Free radical research
    by Fiorito C, Rienzo M, Crimi E, Rossiello R, Balestrieri ML, Casamassimi A, Muto F, Grimaldi V, Giovane A, Farzati B, Mancini FP, Napoli C
    DOI: 10.1080/10715760802357057

    To date, there is no report on the effect of antioxidants on endothelial progenitor cells (EPCs). This study shows that in vitro incubation of EPCs with vitamin C and E reverted the already well documented lowering effect of TNF-alpha on EPC number and increased p-p38 expression levels. In order to document major changes of gene expression levels and gain insight into signalling pathways, microarray analysis was performed and a significant variation of the expression of 5389 genes in EPCs following antioxidant treatment was detected. Also in vivo evidence is provided about the positive effect of antioxidant vitamins on EPCs, since vitamin C and E supplementation potentiated the physical training-induced increase of EPC number and VEGF levels. Together, these data indicate that antioxidant treatment ameliorates EPC number and causes major changes of gene expression within these cells in vitro. Furthermore, concomitant antioxidant supplementation and physical training in vivo raised the levels of circulating EPCs and serum VEGF more than physical training alone.

  • Therapeutic dose of nebivolol, a nitric oxide-releasing beta-blocker, reduces atherosclerosis in cholesterol-fed rabbits.
    Publication Date: 01/08/2008, on Nitric oxide : biology and chemistry
    by de Nigris F, Mancini FP, Balestrieri ML, Byrns R, Fiorito C, Williams-Ignarro S, Palagiano A, Crimi E, Ignarro LJ, Napoli C
    DOI: 10.1016/j.niox.2008.03.004

    Nitric oxide (NO) exerts a plethora of vascular beneficial effects. The NO-releasing beta-blocker nebivolol is a racemic mixture of D/L-enantiomers that displays negative inotropic as well as direct vasodilating activity. The in vivo antiatherogenic activity of therapeutic doses of the beta-blocker with antioxidant properties carvedilol (12.5mg/day) or nebivolol (5mg/day) was tested in cholesterol-fed rabbits. Animals received a 1% cholesterol-rich diet alone (controls) or mixed with drugs (treated animals) for 8 weeks. While it did not affect hyperlipidemia, nebivolol inhibited the development of atherosclerosis, expressed as computer-assisted imaging analysis of aortic area covered by lesions (23.3+/-4.1% in treated vs 38.2+/-6.4% in control animals, p<0.01). Differently, in our experimental condition of therapeutic drug doses, this antiatherogenic effect did not reach statistical significance in rabbits treated with carvedilol (32.5+/-5.1% aortic area covered by lesions, p=NS vs controls). Plasma nitrates increased in rabbits treated with nebivolol while both beta-blockers reduced LDL oxidation. Moreover, nebivolol induced a consistent increase of endothelial reactivity and aortic eNOS expression compared with control animals (p<0.05) and those receiving carvedilol (p<0.05). Since NO may exert beneficial effects in atherosclerosis, a NO-dependent mechanism could explain this data. These observations suggest that the NO-releasing beta-blocker, nebivolol, might represent an effective pharmacological approach for preventing atherosclerotic lesion progression.

  • Suppression of autophagy precipitates neuronal cell death following low doses of methamphetamine.
    Publication Date: 01/08/2008, on Journal of neurochemistry
    by Castino R, Lazzeri G, Lenzi P, Bellio N, Follo C, Ferrucci M, Fornai F, Isidoro C
    DOI: 10.1111/j.1471-4159.2008.05488.x

    Methamphetamine abuse is toxic to dopaminergic neurons, causing nigrostriatal denervation and striatal dopamine loss. Following methamphetamine exposure, the number of nigral cell bodies is generally preserved, but their cytoplasm features autophagic-like vacuolization and cytoplasmic accumulation of alpha-synuclein-, ubiquitin- and parkin-positive inclusion-like bodies. Whether autophagy is epiphenomenal or it plays a role in the mechanism of methamphetamine toxicity and, in the latter case, whether its role consists of counteracting or promoting the neurotoxic effect remains obscure. We investigated the signaling pathway and the significance (protective vs. toxic) of autophagy activation and the convergence of the autophagic and the ubiquitin-proteasome pathways at the level of the same intracellular bodies in a simple cell model of methamphetamine toxicity. We show that autophagy is rapidly up-regulated in response to methamphetamine. Confocal fluorescence microscopy and immuno-electron microscopy studies demonstrated the presence of alpha-synuclein aggregates in autophagy-lysosomal structures in cells exposed to methamphetamine, a condition compatible with cell survival. Inhibition of autophagy either by pharmacologic or genetic manipulation of the class III Phosphatidylinositol-3 kinase-mediated signaling prevented the removal of alpha-synuclein aggregates and precipitated a bax-mediated mitochondrial apoptosis pathway.

  • Prolactin promotes the secretion of active cathepsin D at the basal side of rat mammary acini.
    Publication Date: 01/08/2008, on Endocrinology
    by Castino R, Delpal S, Bouguyon E, Demoz M, Isidoro C, Ollivier-Bousquet M
    DOI: 10.1210/en.2008-0249

    Cathepsin D (CD), a lysosomal aspartic protease present in mammary tissue and milk in various molecular forms, is also found in the incubation medium of mammary acini in molecular forms that are proteolytically active on prolactin at a physiological pH. Because prolactin controls the vesicular traffic in mammary cells, we studied, in vivo and in vitro, its effects on the polarized transport and secretion of various forms of CD in the rat mammary gland. CD accumulated in vesicles not involved in endocytosis in the basal region of cells. Prolactin increased this accumulation and the release of endosomal active single-chain CD at the basal side of acini. The CD-mediated proteolysis of prolactin, leading to the antiangiogenic 16-kDa form, at a physiological pH, was observed only in conditioned medium but not milk. These data support the novel concept that an active molecular form of CD, secreted at the basal side of the mammary epithelium, participates in processing blood-borne prolactin outside the cell, this polarized secretion being controlled by prolactin itself.

  • Physical and functional characterization of the genetic locus of IBtk, an inhibitor of Bruton's tyrosine kinase: evidence for three protein isoforms of IBtk.
    Publication Date: 01/08/2008, on Nucleic acids research
    by Spatuzza C, Schiavone M, Di Salle E, Janda E, Sardiello M, Fiume G, Fierro O, Simonetta M, Argiriou N, Faraonio R, Capparelli R, Quinto I, Scala G
    DOI: 10.1093/nar/gkn413

    Bruton's tyrosine kinase (Btk) is required for B-cell development. Btk deficiency causes X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency (Xid) in mice. Btk lacks a negative regulatory domain and may rely on cytoplasmic proteins to regulate its activity. Consistently, we identified an inhibitor of Btk, IBtk, which binds to the PH domain of Btk and down-regulates the Btk kinase activity. IBtk is an evolutionary conserved protein encoded by a single genomic sequence at 6q14.1 cytogenetic location, a region of recurrent chromosomal aberrations in lymphoproliferative disorders; however, the physical and functional organization of IBTK is unknown. Here, we report that the human IBTK locus includes three distinct mRNAs arising from complete intron splicing, an additional polyadenylation signal and a second transcription start site that utilizes a specific ATG for protein translation. By northern blot, 5'RACE and 3'RACE we identified three IBTKalpha, IBTKbeta and IBTKgamma mRNAs, whose transcription is driven by two distinct promoter regions; the corresponding IBtk proteins were detected in human cells and mouse tissues by specific antibodies. These results provide the first characterization of the human IBTK locus and may assist in understanding the in vivo function of IBtk.

  • Targeting DNA quadruplexes with distamycin A and its derivatives: an ITC and NMR study.
    Publication Date: 01/08/2008, on Biochimie
    by Pagano B, Virno A, Mattia CA, Mayol L, Randazzo A, Giancola C
    DOI: 10.1016/j.biochi.2008.03.006

    The use of small molecules that bind and stabilize G-quadruplex structures is emerging as a promising way to inhibit telomerase activity in tumor cells. In this paper, isothermal titration calorimetry (ITC) and 1H NMR studies have been conducted to examine the binding of distamycin A and its two carbamoyl derivatives (compounds 1 and 2) to the target [d(TGGGGT)]4 and d[AG3(T2AG3)3] quadruplexes from the Tetrahymena and human telomeres, respectively. The interactions were examined using two different buffered solutions containing either K+ or Na+ at a fixed ionic strength, to evaluate any influence of the ions present in solution on the binding behaviour. Experiments reveal that distamycin A and compound 1 bind the investigated quadruplexes in both solution conditions; conversely, compound 2 appears to have a poor affinity in any case. Moreover, these studies indicate that the presence of different cations in solution affects the stoichiometry and thermodynamics of the interactions.

  • Protease treatment affects both invasion ability and biofilm formation in Listeria monocytogenes.
    Publication Date: 01/07/2008, on Microbial pathogenesis
    by Longhi C, Scoarughi GL, Poggiali F, Cellini A, Carpentieri A, Seganti L, Pucci P, Amoresano A, Cocconcelli PS, Artini M, Costerton JW, Selan L
    DOI: 10.1016/j.micpath.2008.01.007

    Listeria monocytogenes is a notably invasive bacterium associated with life-threatening food-borne disease in humans. Several surface proteins have been shown to be essential in the adhesion of L. monocytogenes, and in the subsequent invasion of phagocytes. Because the control of the invasion of host cells by Listeria could potentially hinder its spread in the infected host, we have examined the effects of a protease treatment on the ability of L. monocytogenes to form biofilms and to invade tissues. We have chosen serratiopeptidase (SPEP), an extracellular metalloprotease produced by Serratia marcescens that is already widely used as an anti-inflammatory agent, and has been shown to modulate adhesin expression and to induce antibiotic sensitivity in other bacteria. Treatment of L. monocytogenes with sublethal concentrations of SPEP reduced their ability to form biofilms and to invade host cells. Zymograms of the treated cells revealed that Ami4b autolysin, internalinB, and ActA were sharply reduced. These cell-surface proteins are known to function as ligands in the interaction between these bacteria and their host cells, and our data suggest that treatment with this natural enzyme may provide a useful tool in the prevention of the initial adhesion of L. monocytogenes to the human gut.

  • A novel KIF5A/SPG10 mutation in spastic paraplegia associated with axonal neuropathy.
    Publication Date: 01/07/2008, on Journal of neurology
    by Tessa A, Silvestri G, de Leva MF, Modoni A, Denora PS, Masciullo M, Dotti MT, Casali C, Melone MA, Federico A, Filla A, Santorelli FM
    DOI: 10.1007/s00415-008-0840-8

  • Effect of L-arginine on circulating endothelial progenitor cells and VEGF after moderate physical training in mice.
    Publication Date: 06/06/2008, on International journal of cardiology
    by Fiorito C, Balestrieri ML, Crimi E, Giovane A, Grimaldi V, Minucci PB, Servillo L, D'Armiento FP, Farzati B, Napoli C
    DOI: 10.1016/j.ijcard.2007.12.004

    Alteration of levels and functional activities of circulating endothelial progenitor cells (EPCs) induced by risk factors for coronary heart disease (CHD) profoundly influence their role in the regeneration of tissue ischemia and angiogenesis. Among antioxidant nutrients in the prevention of CHD, L-arginine is particularly effective in enhancing the protection afforded by moderate physical exercise. Here, we aimed to evaluate the effects of L-arginine on EPC levels in C57BL/6J mice subjected to moderate physical exercise. Results showed that supplementation with L-arginine potentiates the effects of moderate physical exercise by increasing significantly EPCs (P<0.001) and VEGF serum levels (P<0.001). Our report highlights the beneficial effect of l-arginine in the modulation of EPC levels and VEGF secretion.

  • High glucose downregulates endothelial progenitor cell number via SIRT1.
    Publication Date: 01/06/2008, on Biochimica et biophysica acta
    by Balestrieri ML, Rienzo M, Felice F, Rossiello R, Grimaldi V, Milone L, Casamassimi A, Servillo L, Farzati B, Giovane A, Napoli C
    DOI: 10.1016/j.bbapap.2008.03.004

    Increasing evidence indicates that mammalian SIRT1 mediates calorie restriction and influences lifespan regulating a number of biological molecules such as FoxO1. SIRT1 controls the angiogenic activity of endothelial cells via deacetylation of FoxO1. Endothelial dysfunction and reduced new blood vessel growth in diabetes involve a decreased bioactivity of endothelial progenitor cells (EPCs) via repression of FoxO1 transcriptional activity. The relative contribution of SIRT1 with respect to the direct effects of high glucose on EPC number is poorly understood. We report that treatment of EPCs with high glucose for 3 days determined a consistent downregulation of EPC positive to DiLDL/lectin staining and, interestingly, this was associated with reduced SIRT1 expression levels and enzyme activity, and increased acetyl-FoxO1 expression levels. Moreover, EPCs responded to high glucose with major changes in the expression levels of cell metabolism-, cell cycle-, and oxidative stress-related genes or proteins. Proteomic analysis shows increased expression of nicotinamide phosphoribosyl transferase and mitochondrial superoxide dismutase whereas a glucose-related heat shock protein is reduced. These findings show that SIRT1 is a critical modulator of EPCs dysfunction during alteration of glucose metabolism.

  • Kissper, a kiwi fruit peptide with channel-like activity: structural and functional features.
    Publication Date: 01/06/2008, on Journal of peptide science : an official publication of the European Peptide Society
    by Ciardiello MA, Meleleo D, Saviano G, Crescenzo R, Carratore V, Camardella L, Gallucci E, Micelli S, Tancredi T, Picone D, Tamburrini M
    DOI: 10.1002/psc.992

    Kissper is a 39-residue peptide isolated from kiwi fruit (Actinidia deliciosa). Its primary structure, elucidated by direct protein sequencing, is identical to the N-terminal region of kiwellin, a recently reported kiwi fruit allergenic protein, suggesting that kissper derives from the in vivo processing of kiwellin. The peptide does not show high sequence identity with any other polypeptide of known function. However, it displays a pattern of cysteines similar, but not identical, to those observed in some plant and animal proteins, including toxins involved in defence mechanisms. A number of these proteins are also active on mammalian cells. Functional characterization of kissper showed pH-dependent and voltage-gated pore-forming activity, together with anion selectivity and channeling in model synthetic PLMs, made up of POPC and of DOPS:DOPE:POPC. A 2DNMR analysis indicates that in aqueous solution kissper has only short regions of regular secondary structure, without any evident similarity with other bioactive peptides. Comparative analysis of the structural and functional features suggests that kissper is a member of a new class of pore-forming peptides with potential effects on human health.

  • Effect of red wine antioxidants and minor polyphenolic constituents on endothelial progenitor cells after physical training in mice.
    Publication Date: 23/05/2008, on International journal of cardiology
    by Balestrieri ML, Fiorito C, Crimi E, Felice F, Schiano C, Milone L, Casamassimi A, Giovane A, Grimaldi V, del Giudice V, Minucci PB, Mancini FP, Servillo L, D'Armiento FP, Farzati B, Napoli C
    DOI: 10.1016/j.ijcard.2007.11.081

    Circulating endothelial progenitor cells (EPCs) play a significant role in regeneration of damaged blood vessels. Levels and functional activities of EPCs are noticeable altered by risk factors for coronary heart disease (CHD) and compounds that can prevent or ameliorate EPC dysfunction are currently of special clinical interest. Here, we evaluate the effects of red wine (RW) on EPCs in C57BL/6J mice subjected to physical exercise. FACS computed counting showed a significant increase of EPC number (P<0.05) in mice after short-term supplementation with RW. VEGF serum concentration was significantly increased by physical training in the presence or absence of RW supplementation (P<0.001). These in vivo observations support previous in vitro observation of the beneficial effect of RW in the modulation of EPC levels.

  • Safety and efficacy of gene transfer for Leber's congenital amaurosis.
    Publication Date: 22/05/2008, on The New England journal of medicine
    by Maguire AM, Simonelli F, Pierce EA, Pugh EN Jr, Mingozzi F, Bennicelli J, Banfi S, Marshall KA, Testa F, Surace EM, Rossi S, Lyubarsky A, Arruda VR, Konkle B, Stone E, Sun J, Jacobs J, Dell'Osso L, Hertle R, Ma JX, Redmond TM, Zhu X, Hauck B, Zelenaia O, Shindler KS, Maguire MG, Wright JF, Volpe NJ, McDonnell JW, Auricchio A, High KA, Bennett J
    DOI: 10.1056/NEJMoa0802315

    Leber's congenital amaurosis (LCA) is a group of inherited blinding diseases with onset during childhood. One form of the disease, LCA2, is caused by mutations in the retinal pigment epithelium-specific 65-kDa protein gene (RPE65). We investigated the safety of subretinal delivery of a recombinant adeno-associated virus (AAV) carrying RPE65 complementary DNA (cDNA) (ClinicalTrials.gov number, NCT00516477 [ClinicalTrials.gov]). Three patients with LCA2 had an acceptable local and systemic adverse-event profile after delivery of AAV2.hRPE65v2. Each patient had a modest improvement in measures of retinal function on subjective tests of visual acuity. In one patient, an asymptomatic macular hole developed, and although the occurrence was considered to be an adverse event, the patient had some return of retinal function. Although the follow-up was very short and normal vision was not achieved, this study provides the basis for further gene therapy studies in patients with LCA.