Latest PUBLICATIONS

  • Estrogen receptor beta localization in the lizard (Podarcis s. sicula) testis.
    Publication Date: 01/02/2004, on Zygote (Cambridge, England)
    by Chieffi P, Varriale B
    DOI:

    There is increasing evidence that 17beta-estradiol is necessary for normal male fertility. The aim of the present study was to characterize estrogen receptor beta (ERbeta) expression in a non-mammalian vertebrate model, the lizard (Podarcis s. sicula) testis. Immunocytochemical analysis shows that ERbeta proteins are present among germ cells in the nucleus of the spermatogonia, in primary spermatocytes and spermatids. Western blot analysis with antibodies against the ERbeta gene product revealed an isoform with a specific weight of 55 kDa. In conclusion, the widespread expression of ERbeta in the Podarcis s. sicula testis is consistent with a role for estrogens in modulating spermatogenesis in the male.

  • Revelation of a new mitochondrial DNA mutation (G12147A) in a MELAS/MERFF phenotype.
    Publication Date: 01/02/2004, on Archives of neurology
    by Melone MA, Tessa A, Petrini S, Lus G, Sampaolo S, di Fede G, Santorelli FM, Cotrufo R
    DOI: 10.1001/archneur.61.2.269

    A 26-year-old man presented at onset with the syndrome of mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS) and later with a phenotype for MELAS and myoclonic epilepsy and ragged red fiber disease (MELAS/MERRF).

  • Mapping phosphorylation sites: a new strategy based on the use of isotopically labelled DTT and mass spectrometry.
    Publication Date: 01/01/2004, on European journal of mass spectrometry (Chichester, England)
    by Amoresano A, Marino G, Cirulli C, Quemeneur E
    DOI: 10.1255/ejms.599

    Phosphoproteomics, nowadays, represents a front line in functional proteomics as testified by the number of papers recently appearing in the literature. In an attempt to improve and simplify the methods so far suggested we have set up a simple isotope-coded approach to label and quantitate phospho-Ser/-Thr residues in protein mixtures. First of all, after appropriate oxidation of cysteine/cystine residues followed by tryptic hydrolysis, we have optimised and simplified the beta-elimination reaction to get the corresponding alkene moiety from the phosphate esters. This was achieved by (a) separating the elimination reaction from the addition reaction, (b) the use of Ba(OH)(2) as alkali reagent and (c) its further elimination by the simple addition of solid CO(2) to the peptide mixture. The Michael reaction was then performed, after the removal of BaCO(3) by centrifugation, by adding dithiothreitol (DTT) to the peptide mixture. Finally, the direct purification of the modified phosphopeptides was performed on a thiol-sepharose column. The availability of fully deuterated DTT, introducing a 6 Da difference with respect to the non-deuterated species, allows quantitation of the differential extent of signalling modification when analysed by matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) and liquid chromatography/mass spectrometry. The entire procedure has been set up by using bovine alpha-casein, and resulted in the identification of all the phosphorylated tryptic peptides, including the tetraphosphorylated peptides, which escaped all previously reported procedures

  • Partial characterization of glycosphingolipids of Agelas sponges in their peracetylated form by liquid secondary ionization mass spectrometry and high-performance liquid chromatography combined with direct electrospray ionization mass spectrometric detection.
    Publication Date: 01/01/2004, on Rapid communications in mass spectrometry : RCM
    by Szilágyi Z, Pócsfalvi G, Costantino V, Mangoni A, Malorni A, Fattorusso E
    DOI: 10.1002/rcm.1720

    Electrospray ionization (ESI) and liquid secondary ionization (LSI) mass spectrometry were applied for characterization of glycosphingolipids (GSLs) isolated in their peracetylated form from four Agelas marine sponge species. Since peracetylated glycosphingolipids are not soluble in solvents traditionally used for ESI, lithium chloride was added to the samples in order to obtain lithium cationized molecules. Although the preferred fragmentation seems to be the sequential loss of acetic acid molecules, it was found that tandem mass spectra obtained from peracetylated diglycosyl ceramides might provide direct information about the structure of the long-chain base (formation of W''/Z0 fragments). The utility of ESI and LSI in the analysis of these compounds has also been compared. It was found that the tandem mass spectra obtained by LSI-MS/MS experiments could provide information about the chain-length (carbon atom number) variations within a certain ceramide mass. Thus, from one of our samples, 25 different ceramide compositions have been identified from 8 precursor (Z0) ions. Comparison of the two ionization modes (LSI and ESI) highlights the fact that molecular mass distributions obtained by LSI-MS, especially the presence of unsaturated species, have to be interpreted carefully. For the first time a direct high-performance liquid chromatography (HPLC)/ESI-MS method was used for characterization of complex mixtures of peracetylated GSLs. The results demonstrate that HPLC/ESI-MS is able to analyze mono- and diglycosylated GSLs, and other kinds of glycolipids that are actually present in the sample.

  • Enhancement of dopaminergic differentiation in proliferating midbrain neuroblasts by sonic hedgehog and ascorbic acid.
    Publication Date: 01/01/2004, on Neural plasticity
    by Volpicelli F, Consales C, Caiazzo M, Colucci-D'Amato L, Perrone-Capano C, di Porzio U
    DOI: 10.1155/NP.2004.45

    We analyzed the molecular mechanisms involved in the acquisition and maturation of dopaminergic (DA) neurons generated in vitro from rat ventral mesencephalon (MES) cells in the presence of mitogens or specific signaling molecules. The addition of basic fibroblast growth factor (bFGF) to MES cells in serum-free medium stimulates the proliferation of neuroblasts but delays DA differentiation. Recombinant Sonic hedgehog (SHH) protein increases up to three fold the number of tyrosine hydroxylase (TH)-positive cells and their differentiation, an effect abolished by anti-SHH antibodies. The expanded cultures are rich in nestin-positive neurons, glial cells are rare, all TH+ neurons are DA, and all DA and GABAergic markers analyzed are expressed. Adding ascorbic acid to bFGF/SHH-treated cultures resulted in a further five- to seven-fold enhancement of viable DA neurons. This experimental system also provides a powerful tool to generate DA neurons from single embryos. Our strategy provides an enriched source of MES DA neurons that are useful for analyzing molecular mechanisms controlling their function and for experimental regenerative approaches in DA dysfunction.

  • Azathioprine and interferon beta(1a) in relapsing-remitting multiple sclerosis patients: increasing efficacy of combined treatment.
    Publication Date: 01/01/2004, on European neurology
    by Lus G, Romano F, Scuotto A, Accardo C, Cotrufo R
    DOI: 10.1159/000074912

    Current treatments of relapsing-remitting multiple sclerosis (RRMS) with immunosuppressive or immunomodulatory drugs have been shown to modify the course of the disease in a significative number of patients. However, in many cases, the response to either interferon beta (IFN-beta) or azathioprine (AZA) treatments was not satisfactory and new therapeutic approaches are needed. We studied clinical and MRI efficacy, safety and tolerance of AZA and IFN-beta(1a) combined therapy in 23 patients with clinically definite RRMS, who had not previously been responsive to either monotherapies. Our cases were divided into three subgroups: 8 previously untreated patients (subgroup A) with at least 2 years of natural course of the disease, 8 patients (subgroup B) previously treated with AZA for 2 years and 7 patients (subgroup C) previously treated with IFN-beta(1a) for 2 years. The baseline Expanded Disability Status Scale (EDSS) ranged from 2 to 4 in all subgroups. All patients completed 2 years of combined treatment with a dose of AZA adjusted to reduce lymphocyte count down to 1,000 +/- 100/microl in association with IFN-beta(1a) at a dose of 6 MIU every other day. The mean number of relapses during the combined treatment period was significantly lower than that observed before combined therapy in all the three subgroups. Also, the mean Delta EDSS score was significantly lower during combined treatment than in monotherapy in subgroups B and C. Moreover, after 2 years of combined treatment, the number of new T(1) hypointense lesions, the number and volume of proton density/T(2) hyperintense lesions and the gadolinium enhancement of T(1) hypointense lesions were significantly lower than before combined treatment. After 2 years of treatment, this combination therapy appears to be safe and well tolerated and no serious side effects were reported. Despite some limitations of our study design, the information regarding efficacy, safety and tolerance of the association of AZA and IFN-beta is most encouraging.

  • Differential sex-independent amygdala response to infant crying and laughing in parents versus nonparents.
    Publication Date: 15/12/2003, on Biological psychiatry
    by Seifritz E, Esposito F, Neuhoff JG, Lüthi A, Mustovic H, Dammann G, von Bardeleben U, Radue EW, Cirillo S, Tedeschi G, Di Salle F
    DOI:

    Animal and human studies implicate forebrain neural circuits in maternal behavior. Here, we hypothesized that human brain response to emotional stimuli relevant for social interactions between infants and adults are modulated by sex- and experience-dependent factors.

  • Stenosis progression after surgical injury in Milan hypertensive rat carotid arteries.
    Publication Date: 01/12/2003, on Cardiovascular research
    by Forte A, Esposito S, De Feo M, Galderisi U, Quarto C, Esposito F, Renzulli A, Berrino L, Cipollaro M, Agozzino L, Cotrufo M, Rossi F, Cascino A
    DOI:

    Milan hypertensive rats (MHS) are characterised by an increase in renal sodium reabsorption mainly related to adducin mutations. Interest in this model relies on the genetic link between adducin polymorphisms and primary hypertension, observed also in a subset of patients.

  • Structural and biochemical characterization of a new type of lectin isolated from carp eggs.
    Publication Date: 01/12/2003, on The Biochemical journal
    by Galliano M, Minchiotti L, Campagnoli M, Sala A, Visai L, Amoresano A, Pucci P, Casbarra A, Cauci M, Perduca M, Monaco HL
    DOI: 10.1042/BJ20030413

    A previously unidentified glycoprotein present in the eggs of the carp ( Cyprinus carpio ) was isolated and structurally characterized. The protein binds to a Sepharose 4B matrix and can be eluted with 0.4 M N -acetylglucosamine. The protein has an apparent molecular mass of 26686.3 Da. On the basis of gel-filtration chromatography, the protein appears to be present in solution as a monomer. The sequence of its 238 amino acids, the position of its four disulphide bridges and the composition of its single N-linked carbohydrate chain were determined. The lectin shows a very low agglutinating activity for human A-type erythrocytes and interacts with both Gram-positive and -negative bacteria. These latter interactions are inhibited by N -acetylglucosamine. A database search shows that its amino acid sequence is similar to that of the members of an invertebrate lectin family that includes tachylectin-1. Tachylectin-1 is present in the amoebocytes of the horseshoe crab, Tachypleus tridentatus, and plays a role in the innate defence system of this species. Homologous genes are also present in other fish, having 85% identity with a gene expressed in the oocytes of the crucian carp ( Carassius auratus gibelio ) and 78% identity with a gene in the cDNA library of the zebrafish ( Danio rerio ).

  • Role of the hinge peptide and the intersubunit interface in the swapping of N-termini in dimeric bovine seminal RNase.
    Publication Date: 01/12/2003, on European journal of biochemistry
    by Ercole C, Avitabile F, Del Vecchio P, Crescenzi O, Tancredi T, Picone D
    DOI:

    Bovine seminal ribonuclease (BS-RNase) is the only known dimeric enzyme characterized by an equilibrium between two different 3D structures: MxM, with exchange (or swapping) of the N-terminal 1-20 residues, and M=M, without exchange. As a consequence, the hinge region 16-22 has a different tertiary structure in the two forms. In the native protein, the equilibrium ratio between MxM and M=M is about 7 : 3. Kinetic analysis of the swapping process for a recombinant sample shows that it folds mainly in the M=M form, then undergoes interconversion into the MxM form, reaching the same 7 : 3 equilibrium ratio. To investigate the role of the regions that are most affected structurally by the swapping, we expressed variant proteins by replacing two crucial residues with the corresponding ones from RNase A: Pro19, within the hinge peptide, and Leu28, located at the interface between subunits. We compared the structural properties of the monomeric forms of P19A-BS-RNase, L28Q-BS-RNase and P19A/L28Q-BS-RNase variants with those of the parent protein, and investigated the exchange kinetics of the corresponding dimers. The P19A mutation slightly increases the thermal stability of the monomer, but it does not alter the swapping tendency of the dimer. In contrast, the L28Q mutation significantly affects both the dimerization and swapping processes but not the thermal stability of the monomer. Overall, these results suggest that the structural determinants that control the exchange of N-terminal arms in BS-RNase may not be located within the hinge peptide, and point to a crucial role of the interface residues.

  • Real-time independent component analysis of fMRI time-series.
    Publication Date: 01/12/2003, on NeuroImage
    by Esposito F, Seifritz E, Formisano E, Morrone R, Scarabino T, Tedeschi G, Cirillo S, Goebel R, Di Salle F
    DOI:

    Real-time functional magnetic resonance imaging (fMRI) enables one to monitor a subject's brain activity during an ongoing session. The availability of online information about brain activity is essential for developing and refining interactive fMRI paradigms in research and clinical trials and for neurofeedback applications. Data analysis for real-time fMRI has traditionally been based on hypothesis-driven processing methods. Off-line data analysis, conversely, may be usefully complemented by data-driven approaches, such as independent component analysis (ICA), which can identify brain activity without a priori temporal assumptions on brain activity. However, ICA is commonly considered a time-consuming procedure and thus unsuitable to process the high flux of fMRI data while they are acquired. Here, by specific choices regarding the implementation, we exported the ICA framework and implemented it into real-time fMRI data analysis. We show that, reducing the ICA input to a few points within a time-series in a sliding-window approach, computational times become compatible with real-time settings. Our technique produced accurate dynamic readouts of brain activity as well as a precise spatiotemporal history of quasistationary patterns in the form of cumulative activation maps and time courses. Results from real and simulated motor activation data show comparable performances for the proposed ICA implementation and standard linear regression analysis applied either in a sliding-window or in a cumulative mode. Furthermore, we demonstrate the possibility of monitoring transient or unexpected neural activities and suggest that real-time ICA may provide the fMRI researcher with a better understanding and control of subjects' behaviors and performances.

  • Creutzfeldt-Jakob disease with a novel extra-repeat insertional mutation in the PRNP gene.
    Publication Date: 11/11/2003, on Neurology
    by Pietrini V, Puoti G, Limido L, Rossi G, Di Fede G, Giaccone G, Mangieri M, Tedeschi F, Bondavalli A, Mancia D, Bugiani O, Tagliavini F
    DOI:

    The authors investigated two unrelated patients with Creutzfeldt-Jakob disease (CJD) with clinical features of sporadic CJD (sCJD) carrying one extra octapeptide repeat in the prion protein (PrP) gene (PRNP). A synaptic type PrP distribution throughout the cerebral gray matter and plaque-like PrP deposits in the subcortical gray structures were detected immunocytochemically. The different patterns of PrP deposition were associated with distinct types of protease-resistant PrP, similar to type 1 and type 2 of sCJD. The features suggest that this insertion is a pathogenic mutation.

  • Altered midbrain dopaminergic neurotransmission during development in an animal model of ADHD.
    Publication Date: 01/11/2003, on Neuroscience and biobehavioral reviews
    by Leo D, Sorrentino E, Volpicelli F, Eyman M, Greco D, Viggiano D, di Porzio U, Perrone-Capano C
    DOI:

    To understand the onset and the molecular mechanisms triggering dopaminergic (DA) dysregulation in Attention-Deficit Hyperactivity Disorder (ADHD), we have used the Spontaneously Hypertensive Rats (SHR), the most widely studied animal model for this disease. We have studied the pattern of expression of specific genes involved in DA neuron differentiation, survival and function during postnatal (P) development of the ventral midbrain in SHR males. Our results show that tyrosine hydroxylase and DA transporter gene expression are significantly and transiently reduced in the SHR midbrain during the first month of postnatal development, although with a different kinetic. The other genes analyzed do not show significant variation between SHR and control rats. In addition, high-affinity DA uptake activity is significantly reduced in synaptosomes obtained from the striatum of 1-month-old SHR, when compared to controls. Our data suggest that down-regulation of DA neurotransmission occurs in the midbrain of SHR in a developmentally regulated temporal window during postnatal development, thus strengthening the hypodopaminergic hypothesis in the pathogenesis of ADHD.

  • Chronic activation of ERK and neurodegenerative diseases.
    Publication Date: 01/11/2003, on BioEssays : news and reviews in molecular, cellular and developmental biology
    by Colucci-D'Amato L, Perrone-Capano C, di Porzio U
    DOI: 10.1002/bies.10355

    The extracellular-signal regulated kinases 1/2 (ERK or ERKs) are involved in the regulation of important neuronal functions, including neuronal plasticity in normal and pathological conditions. We present findings that support the notion that the kinetics and localization of ERK are intrinsically linked, in that the duration of ERK activation dictates its subcellular compartmentalization and/or trafficking. The latter, in turn, dictates whether ERK-expressing cells would enter a program of cell death, survival or differentiation. We summarize experimental data showing that chronic activation of ERK plays a role in the mechanisms that trigger neurodegeneration. We also discuss how MKPs, members of the subclass of dual specificity phosphatases, might be the link between ERK kinetics and its subcellular localization.

  • Identical large scale rearrangement of mitochondrial DNA causes Kearns-Sayre syndrome in a mother and her son.
    Publication Date: 01/11/2003, on Journal of medical genetics
    by Puoti G, Carrara F, Sampaolo S, De Caro M, Vincitorio CM, Invernizzi F, Zeviani M
    DOI: