Latest PUBLICATIONS

  • G-quadruplexes from human telomeric DNA: how many conformations in PEG containing solutions?
    Publication Date: 23/02/2012, on The journal of physical chemistry. B
    by Petraccone L, Malafronte A, Amato J, Giancola C
    DOI: 10.1021/jp209170v

    G-quadruplex structures are an attractive target for the development of anticancer drugs, as their formation in human telomere induces a DNA damage response followed by apoptosis in cancer cells. However, the development of new anticancer drugs by means of structural-based drug design is hampered by a lack of accurate information on the exact G-quadruplex conformation adopted by the human telomeric DNA under physiological conditions. Several groups reported that, in a molecular crowded, cell-like environment, simulated by polyethylene glycol (PEG), the human telomeric DNA adopts the parallel G-quadruplex conformation. These studies have suggested that 40% (w/v) PEG concentration induces complete structural conversion from the other known human telomeric G-quadruplex conformations to the parallel G-quadruplex, thus simplifying the high structural polymorphism existing in the absence of PEG. In this study, we demonstrate that the structural conversion to the parallel G-quadruplex is not a complete reaction at physiological temperature. We report a complete kinetic and thermodynamic characterization of the conformational transitions involving the (TTAGGG)(4)TT and (TTAGGG)(8)TT human telomeric DNA sequences in K(+) solution containing PEG. Our data show that the hybrid-type and parallel conformations coexist at equilibrium in the presence of PEG at physiological temperature and the degree of the quadruplex interconversion depends on the PEG molecular weight. Further, we find that telomeric DNA folds in the parallel quadruplex in the seconds time scale, a much larger time scale than the one reported for the hybrid quadruplex folding (~ms). The whole of our data allow us to predict the relative amount of each G-quadruplex conformation as a function of temperature and time. The effect of other crowding agents like Ficoll 400 and glycerol on the quadruplex interconversion has been also explored.

  • Immunohistochemical localization of receptor for advanced glycation end (RAGE) products in the R6/2 mouse model of Huntington's disease.
    Publication Date: 10/02/2012, on Brain research bulletin
    by Anzilotti S, Giampà C, Laurenti D, Perrone L, Bernardi G, Melone MA, Fusco FR
    DOI: 10.1016/j.brainresbull.2011.01.009

    The receptor for advanced glycation end (RAGE) products is a multi-ligand receptor that belongs to the immunoglobulin superfamily of cell surface receptors, whose ligands are known to be upregulated in neuropathological conditions. RAGE upregulation has been described in neurodegenerative diseases, such as Alzheimer's disease, Creutzfeldt-Jakob's disease and Huntington's disease (HD). To analyze in detail the implication of RAGE in HD, we studied the immunohistochemical distribution of RAGE in the striatum of the R6/2 mouse model of HD, with particular attention to the neuronal subpopulations and their relative vulnerability to HD neurodegeneration. We show that RAGE immunoreactivity is evenly distributed to the cytoplasm of neurons in the wild type mouse, while it is finely granular in the cytoplasm of striatal neurons of R6/2 mouse. RAGE is distributed in 98% of spiny projection neurons, both in the normal mouse and in the R6/2. RAGE co-localizes with all of the striatal interneuron subsets both in the wild-type and in the R6/2 mouse. However, the intensity of RAGE immunoreactivity is significantly higher in the spiny neurons and in the PARV neurons of R6/2 mouse, whereas it is comparable between R6/2 and wild-type in the cholinergic and somatostatinergic interneurons. These data support the concept that RAGE is upregulated in the neurodegenerative process of HD, and suggests that its activation is related to the individual vulnerability of the striatal neuronal subtype.

  • AAV2 gene therapy readministration in three adults with congenital blindness.
    Publication Date: 08/02/2012, on Science translational medicine
    by Bennett J, Ashtari M, Wellman J, Marshall KA, Cyckowski LL, Chung DC, McCague S, Pierce EA, Chen Y, Bennicelli JL, Zhu X, Ying GS, Sun J, Wright JF, Auricchio A, Simonelli F, Shindler KS, Mingozzi F, High KA, Maguire AM
    DOI: 10.1126/scitranslmed.3002865

    Demonstration of safe and stable reversal of blindness after a single unilateral subretinal injection of a recombinant adeno-associated virus (AAV) carrying the RPE65 gene (AAV2-hRPE65v2) prompted us to determine whether it was possible to obtain additional benefit through a second administration of the AAV vector to the contralateral eye. Readministration of vector to the second eye was carried out in three adults with Leber congenital amaurosis due to mutations in the RPE65 gene 1.7 to 3.3 years after they had received their initial subretinal injection of AAV2-hRPE65v2. Results (through 6 months) including evaluations of immune response, retinal and visual function testing, and functional magnetic resonance imaging indicate that readministration is both safe and efficacious after previous exposure to AAV2-hRPE65v2.

  • Stem cell therapy for arterial restenosis: potential parameters contributing to the success of bone marrow-derived mesenchymal stromal cells.
    Publication Date: 01/02/2012, on Cardiovascular drugs and therapy
    by Forte A, Rinaldi B, Sodano L, Berrino L, Rossi F, Finicelli M, Grossi M, Cobellis G, Botti C, De Feo M, Santè P, Galderisi U, Cipollaro M
    DOI: 10.1007/s10557-011-6359-8

    Restenosis is a complex and heterogeneous pathophysiological phenomenon occurring in patients submitted to revascularization procedures. Previous studies proved the antirestenotic properties of injected allogenic mesenchymal stromal cells (MSCs) in an experimental model of rat carotid (re)stenosis induced through arteriotomy. In this study we describe some of the effects subsequent to MSC treatment of rats submitted to carotid arteriotomy and possibly responsible for their antirestenotic effect.

  • Detection, monitoring, and management of trastuzumab-induced left ventricular dysfunction: an actual challenge.
    Publication Date: 01/02/2012, on European journal of heart failure
    by Tocchetti CG, Ragone G, Coppola C, Rea D, Piscopo G, Scala S, De Lorenzo C, Iaffaioli RV, Arra C, Maurea N
    DOI: 10.1093/eurjhf/hfr165

    The antibody trastuzumab, targeted to inhibit the signalling of ErbB2, a tyrosine kinase receptor overexpressed in 20-30% of breast cancers, improves the prognosis in women affected by this tumour, but produces cardiotoxicity, since ErbB2 is also involved in myocardial homeostasis. In this review, we discuss the pathophysiology of trastuzumab cardiomyopathy and the complex interplay between ErbB2 inhibition and anthracyclines, and we focus on the actual challenges of detecting, monitoring, and managing trastuzumab cardiotoxicity: the research of new, sensitive markers of early trastuzumab toxicity, before the ejection fraction is reduced, is an active field of research.

  • A progranulin mutation associated with cortico-basal syndrome in an Italian family expressing different phenotypes of fronto-temporal lobar degeneration.
    Publication Date: 01/02/2012, on Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology
    by Coppola C, Rossi G, Barbarulo AM, Di Fede G, Foglia C, Piccoli E, Piscosquito G, Saracino D, Tagliavini F, Cotrufo R
    DOI: 10.1007/s10072-011-0655-8

    Cortico-basal syndrome (CBS) is a rare neurodegenerative disease characterised by movement and cognitive disorders. It occurs along the spectrum of fronto-temporal lobar degeneration (FTLD), which also includes fronto-temporal dementia (FTD) and progressive supranuclear palsy (PSP). FTLD has recently been shown to be associated with mutations in GRN gene, coding for progranulin, a multifunctional secreted glycoprotein involved in cell cycle, inflammation and tissue repair. We describe the case of a 73-year-old man suffering from CBS with a family history of cognitive disorders belonging to the clinical spectrum of FTLD. Sequencing analysis of GRN in this patient revealed that the C157KfsX97 null mutation has been already described by Le Ber et al. in a French patient affected by an apparently sporadic form of FTD. This report confirms the variability of clinical phenotypes associated with the same mutation and emphasises the importance of genetic analysis in cases with a clear familiarity, as well as in apparently sporadic forms.

  • Development of a fluorescent probe for the study of the sponge-derived simplexide immunological properties.
    Publication Date: 01/02/2012, on Carbohydrate research
    by Di Brisco R, Ronchetti F, Mangoni A, Costantino V, Compostella F
    DOI: 10.1016/j.carres.2011.11.017

    Simplexide is a glycolipid of marine origin, endowed with immunological properties, composed of a long chain secondary alcohol glycosylated by an α-d-glucosyl-(1→4)-β-D-galactosyl disaccharide residue. Herein we describe the preparation of a fluorescent derivative of simplexide, labeled at position 6 of the distal glucose with a dansyl group, as a probe for future studies on the mechanism by which simplexide affects the immune system. Fluorescent simplexide was prepared from a 6″-amino functionalized compound, which in turn was obtained through a highly efficient glycosylation between the preformed activated disaccharide and the long chain secondary alcohol 18-pentatriacontanol.

  • Severe combined immunodeficiences: new and old scenarios.
    Publication Date: 01/02/2012, on International reviews of immunology
    by Aloj G, Giardino G, Valentino L, Maio F, Gallo V, Esposito T, Naddei R, Cirillo E, Pignata C
    DOI: 10.3109/08830185.2011.644607

    Severe combined immunodeficiencies (SCIDs) represent a group of distinct congenital disorders affecting either cell-mediated or humoral immunity, which lead invariably to severe and life-threatening infections. The different forms of SCID are currently classified according to the presence or absence of T, B, and NK cells. This greatly helps define the site of the blockage during the differentiation process. Even though SCID patients share common clinical features, such as opportunistic infections and failure to thrive, irrespective of the underlying pathogenetic mechanism, the discovery of new causative gene alterations led to identify novel complex clinical phenotypes, sometimes associated to extrahematopoietic manifestations. In a few cases, the presenting signs may be peculiar to that specific form and physicians should be alerted in recognizing such complex phenotypes, in order to avoid delay in the diagnostic procedures. The aim of this review is to alert care-givers to take into account also the less frequent clinical features and novel pathogenic mechanisms to direct the functional and molecular studies toward a certain genetic alteration.

  • Synaptosomal protein synthesis in P2 and Ficoll purified fractions.
    Publication Date: 30/01/2012, on Journal of neuroscience methods
    by Eyman M, Cefaliello C, Bruno AP, Crispino M, Giuditta A
    DOI: 10.1016/j.jneumeth.2011.10.007

    Cytoplasmic protein synthesis of brain synaptosomes has generally been determined in the Ficoll purified fraction which contains fewer contaminating mitochondria, microsomes and myelin fragments than the parent P2 fraction. Using a highly selective assay of this activity we have compared the total translation activity and the specific activity of the proteins synthesized by either fraction in control rats and in rats trained for a two-way active avoidance task. In control rats the specific activity remained essentially the same in both fractions but in trained rats the value of the Ficoll fraction was markedly lower (38.5%) than in the P2 fraction. Furthermore, the total translation activity of the Ficoll fraction was 30% lower than in the P2 fraction in control rats and 62% lower in trained rats. These decrements indicate that a large proportion of active synaptosomes present in the P2 fraction is not recovered in the Ficoll fraction, notably in rats undergoing plastic brain changes. We conclude that cytoplasmic protein synthesis of brain synaptosomes is better preserved in the P2 fraction.

  • Occurrence of pipecolic acid and pipecolic acid betaine (homostachydrine) in Citrus genus plants.
    Publication Date: 11/01/2012, on Journal of agricultural and food chemistry
    by Servillo L, Giovane A, Balestrieri ML, Ferrari G, Cautela D, Castaldo D
    DOI: 10.1021/jf204286r

    The presence of pipecolic acid and pipecolic acid betaine, also known as homostachydrine, is herein reported for the first time in Citrus genus plants. Homostachydrine was found in fruits, seeds, and leaves of orange, lemon, and bergamot (Citrus bergamia Risso et Poit). As homostachydrine was not commercially available, as a comparative source, extracts of alfalfa leaves ( Medicago sativa L.) were used, in which homostachydrine is present at high concentration. Then, the results where confirmed by comparison with an authentic standard synthesized and purified starting from pipecolic acid. The synthesized standard was characterized by a ESI-MS/MS study using a 3D ion-trap mass spectrometer. When subjected to MS/MS fragmentation in positive ion mode, homostachydrine, unlike its lower homologue proline betaine (also known as stachydrine), showed a pattern of numerous ionic fragments that allowed unambiguous identification of the compound. For the quantitation in the plant sources, high sensitivity and specificity were achieved by monitoring the transition (158 → 72), which is absent in the fragmentation patterns of other major osmolytes commonly used as markers for studies of abiotic stress. As for the metabolic origin of homostachydrine, the occurrence in citrus plants of pipecolic acid leads to the hypothesis that it could act as a homostachydrine precursor through direct methylation.

  • The E3-ubiquitin ligase TRIM50 interacts with HDAC6 and p62, and promotes the sequestration and clearance of ubiquitinated proteins into the aggresome.
    Publication Date: 01/01/2012, on PloS one
    by Fusco C, Micale L, Egorov M, Monti M, D'Addetta EV, Augello B, Cozzolino F, Calcagnì A, Fontana A, Polishchuk RS, Didelot G, Reymond A, Pucci P, Merla G
    DOI: 10.1371/journal.pone.0040440

    In this study we report that, in response to proteasome inhibition, the E3-Ubiquitin ligase TRIM50 localizes to and promotes the recruitment and aggregation of polyubiquitinated proteins to the aggresome. Using Hdac6-deficient mouse embryo fibroblasts (MEF) we show that this localization is mediated by the histone deacetylase 6, HDAC6. Whereas Trim50-deficient MEFs allow pinpointing that the TRIM50 ubiquitin-ligase regulates the clearance of polyubiquitinated proteins localized to the aggresome. Finally we demonstrate that TRIM50 colocalizes, interacts with and increases the level of p62, a multifunctional adaptor protein implicated in various cellular processes including the autophagy clearance of polyubiquitinated protein aggregates. We speculate that when the proteasome activity is impaired, TRIM50 fails to drive its substrates to the proteasome-mediated degradation, and promotes their storage in the aggresome for successive clearance.

  • Chromatin modification and senescence.
    Publication Date: 01/01/2012, on Current pharmaceutical design
    by Di Bernardo G, Cipollaro M, Galderisi U
    DOI:

    Cells are the fundamental structure composing our bodies and hence cellular decline (called senescence) contributes to ageing. Endogenous and exogenous stresses may induce cellular senescence. Stressors are mainly macromolecule damage events, which include: shortening of chromosome telomeres; non-telomeric DNA damage; excessive mitogenic signals, which may cause DNA damage; and non-genotoxic stress, such as perturbations to chromatin organization. For many years the analysis of chromatin perturbation as a leading event in triggering senescence has been overlooked. Now, it is well recognized that chromatin DNA packaging is not immune to the ravages of time. All eukaryotes experience changes in chromatin organization and gene-expression patterns as they age. This can be due to perturbation in the function of chromatin modifiers. In this review we will discuss the role in the senescence process of the different types of chromatin modifiers, such as the ATP-dependent chromatin remodelling complexes, the enzymes that covalently modify histone tails and proteins involved in DNA methylation.

  • Morphological and molecular characterization of healthy human ascending aorta.
    Publication Date: 01/01/2012, on Histology and histopathology
    by Forte A, Della Corte A, Grossi M, Finicelli M, Bancone C, Provenzano R, Pepino P, Nappi GA, De Feo M, Galderisi U, Cotrufo M, Cipollaro M
    DOI: 10.14670/HH-27.103

    Knowledge of the characteristics of the normal human aorta has been constrained by lack of data on fresh aortic tissue, especially from healthy individuals. In this study, the gene expression and morphological characteristics of the thoracic ascending aorta (AA) of healthy organ donors have been evaluated, with the aim of providing reference data for the analysis of pathological AAs. We analysed by RT-PCR the differential expression of mRNAs coding for myocardin, smoothelin, alpha-smooth muscle actin (alpha-SMA) and the ED-A isoform of fibronectin (ED-A FN) in AA specimens from donors, integrating the results with immunohistochemical analysis of the same targets. Morphological and morphometric characteristics of the AAs were also evaluated. In order to account for possible regional variations in wall structure, the convexity of the aortic profile was compared to the concavity. No differences in gene expression occurred for any of the target genes between the concavity and the convexity of AAs. Immunohistochemistry revealed a different distribution of total FN and of its ED-A isoform in the media and in the intima. Smoothelin is expressed by the majority of cells in the media, with some positive cells also in the intima. Alpha-SMA is expressed in all the tunicae. Immunohistochemistry also revealed in the convexity of 50% of AAs the presence of discrete areas in the subadventital media with altered structure and cell morphology and with altered gene expression, resulting positive for ED-A FN and alpha-SMA, but not for smoothelin, indicating the occurrence of early lesions also in macroscopically healthy AAs.

  • Neuropsychological correlates of theory of mind in patients with early Parkinson's disease.
    Publication Date: 01/01/2012, on Movement disorders : official journal of the Movement Disorder Society
    by Santangelo G, Vitale C, Trojano L, Errico D, Amboni M, Barbarulo AM, Grossi D, Barone P
    DOI: 10.1002/mds.23949

    The theory of mind is the ability to attribute mental states to oneself and others and to understand that others have beliefs, desires and intentions different from one's own. The aim of the study was to explore the neuropsychological correlates of theory of mind in patients affected by early Parkinson's disease (PD). Thirty-three PD patients and 33 age-, sex-, and education-matched control subjects underwent the Frontal Assessment Battery, as well as tasks assessing "cognitive" and "affective" theory of mind, and memory abilities; questionnaires evaluating behavioral disorders and quality of life were also administrated. Although the 2 groups did not differ on neuropsychological tasks, PD patients' performance on tasks assessing cognitive and affective theory of mind was significantly worse than controls. Moreover, PD patients had more behavioral disorders and worse quality of life than controls. After covarying for behavioral and quality of life scores, the differences between patients and controls on theory of mind tasks remained significant. "Cognitive" theory of mind was associated with Frontal Assessment Battery score and 2 domains of quality of life scale, whereas "affective" theory of mind scores correlated only with behavioral scales such as the Frontal Behavioral Inventory and Apathy Evaluation Scale. The results demonstrate that both affective and cognitive aspects of theory of mind are simultaneously impaired in early PD and suggest that deficits in the 2 subcomponents of theory of mind may be linked to dysfunction of different frontosubcortical circuitries in early PD.

  • Identification of sumoylation sites in CCDC6, the first identified RET partner gene in papillary thyroid carcinoma, uncovers a mode of regulating CCDC6 function on CREB1 transcriptional activity.
    Publication Date: 01/01/2012, on PloS one
    by Luise C, Merolla F, Leone V, Paladino S, Sarnataro D, Fusco A, Celetti A
    DOI: 10.1371/journal.pone.0049298

    CCDC6 was originally identified in chimeric genes as caused by chromosomal translocation involving the RET protooncogene in some thyroid tumors. Recognised as a 65 kDa pro-apoptotic phosphoprotein, CCDC6 has been enrolled as an ATM substrate that contribute to protect genome integrity by modulating PP4c activity in response to genotoxic stress. Recently, CCDC6 has been identified as a repressor of CREB1-dependent transcription. Sumoylation has emerged as an important mechanism in transcriptional control. Here, we report the identification and characterization of three sites of sumoylation in CCDC6 (K74, K266 and K424) which are highly conserved in vertebrates. We demonstrate that the post-translational modifications by SUMO2 constrain most of the CCDC6 protein in the cytosol and affect its functional interaction with CREB1 with a decrease of CCDC6 repressive function on CREB1 transcriptional activity. Indeed, the impairment of functional outcome of sumoylated CCDC6 is obtained knocking down all three the sumoylation sites. Interestingly, in thyroid cells the SUMO2-mediated CCDC6 post-translational modifications are induced by Forskolin, a cAMP analog. Signal transduction via the cAMP pathway is known to be ubiquitous and represents a major line of communication between many organisms and their environment. We believe that CCDC6 could be an important player in the dynamics of cAMP signaling by fine regulating CREB1 transcriptional activity in normal and transformed thyroid cells.