Latest PUBLICATIONS

  • Pancreatic cancer-derived S-100A8 N-terminal peptide: a diabetes cause?
    Publication Date: 01/10/2006, on Clinica chimica acta; international journal of clinical chemistry
    by Basso D, Greco E, Fogar P, Pucci P, Flagiello A, Baldo G, Giunco S, Valerio A, Navaglia F, Zambon CF, Falda A, Pedrazzoli S, Plebani M
    DOI: 10.1016/j.cca.2006.03.027

    Our aim was to identify the pancreatic cancer diabetogenic peptide.

  • Structure and function of the long pentraxin PTX3 glycosidic moiety: fine-tuning of the interaction with C1q and complement activation.
    Publication Date: 26/09/2006, on Biochemistry
    by Inforzato A, Peri G, Doni A, Garlanda C, Mantovani A, Bastone A, Carpentieri A, Amoresano A, Pucci P, Roos A, Daha MR, Vincenti S, Gallo G, Carminati P, De Santis R, Salvatori G
    DOI: 10.1021/bi0607453

    The prototypic long pentraxin PTX3 is a unique fluid-phase pattern recognition receptor that plays a nonredundant role in innate immunity and female fertility. The PTX3 C-terminal domain is required for C1q recognition and complement activation and contains a single N-glycosylation site on Asn 220. In the present study, we characterized the structure of the human PTX3 glycosidic moiety and investigated its relevance in C1q interaction and activation of the complement classical pathway. By specific endo and exoglycosidases digestion and direct mass spectrometric analysis, we found that both recombinant and naturally occurring PTX3 were N-linked to fucosylated and sialylated complex-type sugars. Interestingly, glycans showed heterogeneity mainly in the relative amount of bi, tri, and tetrantennary structures depending on the cell type and inflammatory stimulus. Enzymatic removal of sialic acid or the entire glycosidic moiety equally enhanced PTX3 binding to C1q compared to that in the native protein, thus indicating that glycosylation substantially contributes to modulate PTX3/C1q interaction and that sialic acid is the main determinant of this contribution. BIAcore kinetic measurements returned decreasing K(off) values as sugars were removed, pointing to a stabilization of the PTX3/C1q complex. No major rearrangement of PTX3 quaternary structure was observed after desialylation or deglycosylation as established by size exclusion chromatography. Consistent with C1q binding, PTX3 desialylation enhanced the activation of the classical complement pathway, as assessed by C4 and C3 deposition. In conclusion, our results provided evidence of an involvement of the PTX3 sugar moiety in C1q recognition and complement activation.

  • Brain and behavioural evidence for rest-activity cycles in Octopus vulgaris.
    Publication Date: 25/09/2006, on Behavioural brain research
    by Brown ER, Piscopo S, De Stefano R, Giuditta A
    DOI: 10.1016/j.bbr.2006.05.009

    Octopus vulgaris maintained under a 12/12h light/dark cycle exhibit a pronounced nocturnal activity pattern. Animals deprived of rest during the light period show a marked 'rebound' in activity in the following 24h. 'Active' octopuses attack faster than 'quiet' animals and brain activity recorded electrically intensifies during 'quiet' behaviour. Thus, in Octopus as in vertebrates, brain areas involved in memory or 'higher' processes exhibit 'off-line' activity during rest periods.

  • Solution structure of a chemosensory protein from the desert locust Schistocerca gregaria.
    Publication Date: 05/09/2006, on Biochemistry
    by Tomaselli S, Crescenzi O, Sanfelice D, Ab E, Wechselberger R, Angeli S, Scaloni A, Boelens R, Tancredi T, Pelosi P, Picone D
    DOI: 10.1021/bi060998w

    Chemical stimuli, generally constituted by small volatile organic molecules, are extremely important for the survival of different insect species. In the course of evolution, insects have developed very sophisticated biochemical systems for the binding and the delivery of specific semiochemicals to their cognate membrane-bound receptors. Chemosensory proteins (CSPs) are a class of small soluble proteins present at high concentration in insect chemosensory organs; they are supposed to be involved in carrying the chemical messages from the environment to the chemosensory receptors. In this paper, we report on the solution structure of CSPsg4, a chemosensory protein from the desert locust Schistocerca gregaria, which is expressed in the antennae and other chemosensory organs. The 3D NMR structure revealed an overall fold consisting of six alpha-helices, spanning residues 13-18, 20-31, 40-54, 62-78, 80-90, and 97-103, connected by loops which in some cases show dihedral angles typical of beta-turns. As in the only other chemosensory protein whose structure has been solved so far, namely, CSP from the moth Mamestra brassicae, four helices are arranged to form a V-shaped motif; another helix runs across the two V's, and the last one is packed against the external face. Analysis of the tertiary structure evidenced multiple hydrophobic cavities which could be involved in ligand binding. In fact, incubation of the protein with a natural ligand, namely, oleamide, produced substantial changes to the NMR spectra, suggesting extensive conformational transitions upon ligand binding.

  • Clinical phenotype of an Italian family with a new mutation in the PRPF8 gene.
    Publication Date: 01/09/2006, on European journal of ophthalmology
    by Testa F, Ziviello C, Rinaldi M, Rossi S, Di Iorio V, Interlandi E, Ciccodicola A, Banfi S, Simonelli F
    DOI:

    To report the clinical and functional characteristics of an autosomal dominant retinitis pigmentosa (ADRP) family with a novel point mutation (P2301S) in the PRPF8 gene.

  • Polymorphism p.402Y>H in the complement factor H protein is a risk factor for age related macular degeneration in an Italian population.
    Publication Date: 01/09/2006, on The British journal of ophthalmology
    by Simonelli F, Frisso G, Testa F, di Fiore R, Vitale DF, Manitto MP, Brancato R, Rinaldi E, Sacchetti L
    DOI: 10.1136/bjo.2006.096487

    To evaluate the complement factor H (CFH) p.402Y>H polymorphism as a risk factor in age related macular degeneration (AMD) in an Italian population.

  • The end of the central dogma of neurobiology: stem cells and neurogenesis in adult CNS.
    Publication Date: 01/09/2006, on Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology
    by Colucci-D'Amato L, Bonavita V, di Porzio U
    DOI: 10.1007/s10072-006-0682-z

    Until the 1990s, neurologists were practising their profession under the doctrine established in the late 19th to early 20th century by the prominent histologist Ramon y Cajal: "Once the development was ended, the founts of growth and regeneration of the axons and dendrites dried up irrevocably. In the adult centers, the nerve paths are something fixed, ended, and immutable. Everything may die, nothing may be regenerated. It is for the science of the future to change, if possible, this harsh decree." Similarly, Giulio Bizzozero, the most prominent Italian histologist and mentor of Camillo Golgi, classified the tissues of the human body into "labile, stable and perennial". Among the latter were the nerve cells, believed to be unable to proliferate in the postnatal brain. This classification was taught until a few years ago to generations of medical students and biologists all over the world. We have investigated the historical, methodological and technical reasons why this "central dogma of neurology", so influential in clinical and experimental neurology, has lasted so long. We examined how this dogma was broken and who contributed, and the difficulties encountered by the "heretical" researchers who contributed to this goal, especially between the 1960s and the early 1990s, when at last neurogenesis in the adult brain could no longer be denied. Finally, we propose that the understanding of the mechanisms underlying various neurological diseases and the interpretations of clinical syndromes, as well as the design of new therapies, are being revolutionised by the breaking of this dogma and the discovery of the presence of neural stem cells in the adult brain.

  • Methylphenidate administration to adolescent rats determines plastic changes on reward-related behavior and striatal gene expression.
    Publication Date: 01/09/2006, on Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
    by Adriani W, Leo D, Greco D, Rea M, di Porzio U, Laviola G, Perrone-Capano C
    DOI: 10.1038/sj.npp.1300962

    Administration of methylphenidate (MPH, Ritalin) to children with attention deficit hyperactivity disorder (ADHD) is an elective therapy, but raises concerns for public health, due to possible persistent neurobehavioral alterations. Wistar adolescent rats (30 to 46 day old) were administered MPH or saline (SAL) for 16 days, and tested for reward-related and motivational-choice behaviors. When tested in adulthood in a drug-free state, MPH-pretreated animals showed increased choice flexibility and economical efficiency, as well as a dissociation between dampened place conditioning and more marked locomotor sensitization induced by cocaine, compared to SAL-pretreated controls. The striatal complex, a core component of the natural reward system, was collected both at the end of the MPH treatment and in adulthood. Genome-wide expression profiling, followed by RT-PCR validation on independent samples, showed that three members of the postsynaptic-density family and five neurotransmitter receptors were upregulated in the adolescent striatum after subchronic MPH administration. Interestingly, only genes for the kainate 2 subunit of ionotropic glutamate receptor (Grik2, also known as KA2) and the 5-hydroxytryptamine (serotonin) receptor 7 (Htr7) (but not GABA(A) subunits and adrenergic receptor alpha1b) were still upregulated in adulthood. cAMP responsive element-binding protein and Homer 1a transcripts were modulated only as a long-term effect. In summary, our data indicate short-term changes in neural plasticity, suggested by modulation of expression of key genes, and functional changes in striatal circuits. These modifications might in turn trigger enduring changes responsible for the adult neurobehavioral profile, that is, altered processing of incentive values and a modified flexibility/habit balance.

  • Cardenolide glycosides from Pergularia tomentosa and their proapoptotic activity in Kaposi's sarcoma cells.
    Publication Date: 01/09/2006, on Journal of natural products
    by Hamed AI, Plaza A, Balestrieri ML, Mahalel UA, Springuel IV, Oleszek W, Pizza C, Piacente S
    DOI: 10.1021/np060228l

    Continuing our investigations on plants belonging to the Asclepiadaceae family, three new cardenolide glycosides, 3'-O-beta-D-glucopyranosylcalactin (1), 12-dehydroxyghalakinoside (2), and 6'-dehydroxyghalakinoside (3), along with the known ghalakinoside (4) and calactin (5), were isolated from the roots of Pergularia tomentosa. The structures of these compounds were elucidated by extensive spectroscopic methods including 1D- and 2D-NMR experiments as well as ESIMS analysis. The isolated cardenolides caused apoptotic cell death of Kaposi's sarcoma cells.

  • How does spatial extent of fMRI datasets affect independent component analysis decomposition?
    Publication Date: 01/09/2006, on Human brain mapping
    by Aragri A, Scarabino T, Seifritz E, Comani S, Cirillo S, Tedeschi G, Esposito F, Di Salle F
    DOI: 10.1002/hbm.20215

    Spatial independent component analysis (sICA) of functional magnetic resonance imaging (fMRI) time series can generate meaningful activation maps and associated descriptive signals, which are useful to evaluate datasets of the entire brain or selected portions of it. Besides computational implications, variations in the input dataset combined with the multivariate nature of ICA may lead to different spatial or temporal readouts of brain activation phenomena. By reducing and increasing a volume of interest (VOI), we applied sICA to different datasets from real activation experiments with multislice acquisition and single or multiple sensory-motor task-induced blood oxygenation level-dependent (BOLD) signal sources with different spatial and temporal structure. Using receiver operating characteristics (ROC) methodology for accuracy evaluation and multiple regression analysis as benchmark, we compared sICA decompositions of reduced and increased VOI fMRI time-series containing auditory, motor and hemifield visual activation occurring separately or simultaneously in time. Both approaches yielded valid results; however, the results of the increased VOI approach were spatially more accurate compared to the results of the decreased VOI approach. This is consistent with the capability of sICA to take advantage of extended samples of statistical observations and suggests that sICA is more powerful with extended rather than reduced VOI datasets to delineate brain activity.

  • The retinoblastoma gene is involved in multiple aspects of stem cell biology.
    Publication Date: 28/08/2006, on Oncogene
    by Galderisi U, Cipollaro M, Giordano A
    DOI: 10.1038/sj.onc.1209736

    Genetic programs controlling self-renewal and multipotentiality of stem cells have overlapping pathways with cell cycle regulation. Components of cell cycle machinery can play a key role in regulating stem cell self-renewal, proliferation, differentiation and aging. Among the negative regulators of cell cycle progression, the RB family members play a prominent role in controlling several aspects of stem cell biology. Stem cells contribute to tissue homeostasis and must have molecular mechanisms that prevent senescence and hold 'stemness'. RB can induce senescence-associated changes in gene expression and its activity is downregulated in stem cells to preserve self-renewal. Several reports evidenced that RB could play a role in lineage specification of several types of stem cells. RB has a role in myogenesis as well as in cardiogenesis. These effects are not only related to its role in suppressing E2F-responsive genes but also to its ability to modulate the activity of tissue-specific transcription factors. RB is also involved in adipogenesis through a strict control of lineage commitment and differentiation of adipocytes as well in determining the switch between brown and white adipocytes. Also, hematopoietic progenitor cells utilize the RB pathway to modulate cell commitment and differentiation. In this review, we will also discuss the role of the other two RB family members: Rb2/p130 and p107 showing that they have both specific and overlapping functions with RB gene.

  • Partial purification and MALDI-TOF MS analysis of UN1, a tumor antigen membrane glycoprotein.
    Publication Date: 15/08/2006, on International journal of biological macromolecules
    by de Laurentiis A, Caterino M, Orrù S, Ruoppolo M, Tuccillo F, Masullo M, Quinto I, Scala G, Pucci P, Palmieri C, Tassone P, Salvatore F, Venuta S
    DOI: 10.1016/j.ijbiomac.2006.02.020

    UN1 is a membrane glycoprotein that is expressed in immature human thymocytes, a subpopulation of peripheral T lymphocytes, the HPB acute lymphoblastic leukemia (ALL) T-cell line and fetal thymus. We previously reported the isolation of a monoclonal antibody (UN1 mAb) recognizing the UN1 protein that was classified as "unclustered" at the 5th and 6th International Workshop and Conference on Human Leukocyte Differentiation Antigens. UN1 was highly expressed in breast cancer tissues and was undetected in non-proliferative lesions and in normal breast tissues, indicating a role for UN1 in the development of a tumorigenic phenotype of breast cancer cells. In this study, we report a partial purification of the UN1 protein from HPB-ALL T cells by anion-exchange chromatography followed by immunoprecipitation with the UN1 mAb and MALDI-TOF MS analysis. This analysis should assist in identifying the amino acid sequence of UN1.

  • Short-term effects of adolescent methylphenidate exposure on brain striatal gene expression and sexual/endocrine parameters in male rats.
    Publication Date: 01/08/2006, on Annals of the New York Academy of Sciences
    by Adriani W, Leo D, Guarino M, Natoli A, Di Consiglio E, De Angelis G, Traina E, Testai E, Perrone-Capano C, Laviola G
    DOI: 10.1196/annals.1369.005

    Exposure to methylphenidate (MPH) during adolescence is the elective therapy for attention deficit/hyperactivity disorder (ADHD) children, but raises major concerns for public health, due to possibly persistent neurobehavioral changes. Rats (30- to 44-days old) were administered MPH (2 mg/kg, i.p once daily) or saline (SAL). At the end of the treatment we collected plasma, testicular, liver, and brain (striatum) samples. The testes and liver were used to evaluate conventional reproductive and metabolic endpoints. Testes of MPH-exposed rats weighed more and contained an increased quantity of sperm, whereas testicular levels of testosterone (TST) were markedly decreased. The MPH treatment exerted an inductive effect on enzymatic activity of TST hydroxylases, resulting in increased hepatic TST catabolism. These findings suggest that subchronic MPH exposure in adolescent rats could have a trophic action on testis growth and a negative impact on TST metabolism. We have analyzed striatal gene expression profiles as a consequence of MPH exposure during adolescence, using microarray technology. More than 700 genes were upregulated in the striatum of MPH-treated rats (foldchange >1.5). A first group of genes were apparently involved in migration of immature neural/glial cells and/or growth of novel axons. These genes include matrix proteases (ADAM-1, MMP14), their inhibitors (TIMP-2, TIMP-3), the hyaluronan-mediated motility receptor (RHAMM), and growth factors (transforming growth factor-beta3 [TGF-beta3] and fibroblast growth factor 14 [FGF14]). A second group of genes were suggestive of active axonal myelination. These genes mediate survival of immature cells after contact with newly produced axonal matrix (laminin B1, collagens, integrin alpha 6) and stabilization of myelinating glia-axon contacts (RAB13, contactins 3 and 4). A third group indicated the appearance and/or upregulation of mature processes. The latter included genes for: K+ channels (TASK-1, TASK-5), intercellular junctions (connexin30), neurotransmitter receptors (adrenergic alpha 1B, kainate 2, serotonin 7, GABA-A), as well as major proteins responsible for their transport and/or anchoring (Homer 1, MAGUK MPP3, Shank2). All these genes were possibly involved in synaptic plasticity, namely the formation, maturation, and stabilization of new neural connections within the striatum. MPH treatment seems to potentiate synaptic plasticity, which is an age-dependent developmental phenomenon that adolescent rats are very likely to show, compared to adults. Our observations suggest that adolescent MPH exposure causes only transient changes in reproductive and hormonal parameters, and a more enduring enhancement of neurobehavioral plasticity.

  • Targeting c-Myc, Ras and IGF cascade to treat cancer and vascular disorders.
    Publication Date: 01/08/2006, on Cell cycle (Georgetown, Tex.)
    by de Nigris F, Balestrieri ML, Napoli C
    DOI: 10.4161/cc.5.15.3138

    Cancer and vascular diseases remain the predominant causes of morbidity and mortality in industrialized countries worldwide. The course of atherosclerosis with initiation, progression, and complication parallels the three stages of carcinogenesis with induction, growth, and invasion of tissue and neoangiogenesis. Within this framework, the oncogene c-Myc and growth factors pathways are acquiring increasing importance. Insulin-like growth factor-1 (IGF-1) pathway emerges among them for its versatile pleiotropic actions. A number of genes that permit extensive communication between IGF-1-AKT, p53, and mammalian target of rapamycin (mTOR) pathways have been identified. In turn these pathways lead to p53 transcriptional program, the forkhead transcriptional programs, autophagy, and translational controls, which determine cell growth or arrest, cell survival or death. The increased understanding of the extensive communication and coordination between all these pathways may enable to targeting these events and to prevent neoplastic and vascular diseases. Great effort has been focused on the development of new agents designed to target various steps of c-Myc, Ras, and IGF cascade. However, what have we recently learned about their safety and effectiveness? Here, we review the very recent advances in the identification of novel inhibitors as well as antisense oligonuleotides (ASOs) and siRNA that are proving their usefulness in ongoing clinical trials both in terms of toxicity and specificity.

  • The importance of electrostatic potential in the interaction of sweet proteins with the sweet taste receptor.
    Publication Date: 07/07/2006, on Journal of molecular biology
    by Esposito V, Gallucci R, Picone D, Saviano G, Tancredi T, Temussi PA
    DOI: 10.1016/j.jmb.2006.05.020

    In addition to many small molecular mass sweeteners there are in nature a few sweet proteins. The molecular volume of sweet proteins is so different from that of common sweeteners that it was difficult to understand how molecules as large as proteins can activate a receptor designed to host small molecules. We have recently shown that sweet proteins can activate the sweet receptor by a mechanism of interaction, called ''wedge model", in which proteins fit a large cavity of the receptor with wedge-shaped surfaces of their structures. In order to substantiate this model we have designed, expressed and characterized seven mutants of MNEI, a single chain monellin. Three uncharged residues of the interaction surface, Met42, Tyr63 and Tyr65, were changed either into acidic or basic residues whereas Asp68, a key acidic residue, was changed into a basic one. As a general trend, we observe that an increase of the negative charge is much more detrimental for sweetness than an increase of positive charge. In addition we show that by a careful choice of a residue at the center of the interface between MNEI and receptor, it is possible even to increase the sweetness of MNEI. These results are fully consistent with the wedge model.