Latest PUBLICATIONS

  • The influence of interoceptive awareness on functional connectivity in patients with irritable bowel syndrome.
    Publication Date: 04/10/2016, on Brain imaging and behavior
    by Longarzo M, Quarantelli M, Aiello M, Romano M, Del Prete A, Cimminiello C, Cocozza S, Olivo G, Loguercio C, Trojano L, Grossi D
    DOI: 10.1007/s11682-016-9595-5

    Irritable bowel syndrome (IBS) is characterized by visceral hypersensitivity likely related to altered processing of sensory stimuli along the brain-gut axis. Previous neuroimaging studies demonstrated structural and functional alteration of several brain areas involved in bodily representation, e.g. the insula, in patients with IBS. By means of resting-state functional magnetic resonance imaging (rs-fMRI) we searched for alteration of functional connectivity within the network involved in self-bodily consciousness. We found significant inverse correlation between hypochondriasis assessed through a clinical questionnaire and connectivity between posterior cingulate cortex and left supramarginal gyrus, extending into the adjacent superior temporal gyrus. Moreover, we observed a significant and positive correlation between a clinical questionnaire assessing interoception and connectivity between left anterior ventral insula and two clusters located in supramarginal gyrus bilaterally.Our findings highlight an "abnormal network synchrony" reflecting functional alteration, in the absence of structural and micro-structural changes, which might represent a possible therapeutic target for Irritable Bowel Syndrome.

  • Sarcopenia in Elderly Diabetic Patients: Role of Dipeptidyl Peptidase 4 Inhibitors.
    Publication Date: 01/10/2016, on Journal of the American Medical Directors Association
    by Rizzo MR, Barbieri M, Fava I, Desiderio M, Coppola C, Marfella R, Paolisso G
    DOI: 10.1016/j.jamda.2016.04.016

    Our study aimed to investigate the effect of dipeptidyl peptidase 4 inhibitors (DPP4-I) on sarcopenic parameters in elderly type 2 diabetic patients.

  • Long-term outcome of patients with disorders of consciousness with and without epileptiform activity and seizures: a prospective single centre cohort study.
    Publication Date: 01/10/2016, on Journal of neurology
    by Pascarella A, Trojano L, Loreto V, Bilo L, Moretta P, Estraneo A
    DOI: 10.1007/s00415-016-8232-y

    Brain-injured patients can experience epileptic seizures beyond 1 week from injury (unprovoked remote symptomatic epileptic seizures). In our longitudinal observational study, we analysed occurrence of unprovoked remote epileptic seizures and interictal epileptiform activity in 130 traumatic, vascular or anoxic inpatients with disorders of consciousness (DOC), with a clinical diagnosis of vegetative state (n = 97) or minimally conscious state (n = 33). We also investigated impact of epileptic seizures and epileptiform activity on clinical outcome (30 months post-onset). Epileptic seizures occurred in 35/130 patients (26.9 %), epileptiform activity in 61/130 (46.9 %) patients, without significant differences related to clinical diagnosis or aetiology. Among patients with epileptiform activity, only 26/61 (42.6 %) developed clinically evident seizures. Mortality at 30 months was not significantly influenced by the presence of seizures or epileptiform activity. The proportion of patients who recovered at long-term follow-up was higher in patients without than in patients with epileptic seizures, but was similar in patients with or without epileptiform activity. The presence of epileptic seizures but not of epileptiform activity, significantly affected the level of responsiveness at final outcome. In conclusion, seizures were detected in about one third of the whole sample, and in about a half of patients with epileptiform activity, regardless of clinical diagnosis or aetiology. Although epileptic seizures or epileptiform activity did not significantly affect mortality rate, we demonstrated that epileptic seizures could hamper recovery of consciousness. Epileptic seizures thus qualify as one of the factors largely undetermined at the moment which can influence prognosis in DOC patients.

  • Mental simulation of drawing actions enhances delayed recall of a complex figure.
    Publication Date: 01/10/2016, on Experimental brain research
    by De Lucia N, Trojano L, Senese VP, Conson M
    DOI: 10.1007/s00221-016-4696-3

    Motor simulation implies that the same motor representations involved in action execution are re-enacted during observation or imagery of actions. Neurofunctional data suggested that observation of letters or abstract paintings can elicit simulation of writing or drawing gestures. We performed four behavioural experiments on right-handed healthy participants to test whether observation of a static and complex geometrical figure implies re-enactment of drawing actions. In Experiment 1, participants had to observe the stimulus without explicit instruction (observation-only condition), while performing irrelevant finger tapping (motor dual task), or while articulating irrelevant verbal material (verbal dual task). Delayed drawing of the stimulus was less accurate in the motor dual-task (interfering with simulation of hand actions) than in verbal dual-task and observation-only conditions. In Experiment 2, delayed drawing in the observation only was as accurate as when participants encoded the stimulus by copying it; in both conditions, accuracy was higher than when participants were instructed to observe the stimulus to recall it later verbally (observe to recall), thus being discouraged from engaging motor simulation. In Experiment 3, delayed drawing was as accurate in the observation-only condition as when participants imagined copying the stimulus; accuracy in both conditions was higher than in the observe-to-recall condition. In Experiment 4, in the observe-only condition participants who observed the stimulus with their right arm hidden behind their back were significantly less accurate than participants who had their left arm hidden. These findings converge in suggesting that mere observation of a geometrical stimulus can activate motor simulation and re-enactment of drawing actions.

  • Influence of pH on the structure and stability of the sweet protein MNEI.
    Publication Date: 01/10/2016, on FEBS letters
    by Spadaccini R, Leone S, Rega MF, Richter C, Picone D
    DOI: 10.1002/1873-3468.12437

    MNEI is a single-chain derivative of the sweet protein monellin that, in recent years, has become an accepted model for studying protein dynamic properties such as folding and aggregation. Although MNEI is very resistant at acidic pH, exposure to neutral or alkaline pH strongly affects its stability. We have performed a thorough NMR study of the dynamic properties of MNEI at different pHs. The results demonstrate that, at physiological temperature, exposure to higher pH increases MNEI flexibility. The changes, originating from a well-defined region in the protein, are transmitted to the whole structure and are likely to be the key for triggering unfolding processes.

  • Intermolecular disulfide bond influences unphosphorylated STAT3 dimerization and function.
    Publication Date: 01/10/2016, on The Biochemical journal
    by Butturini E, Gotte G, Dell'Orco D, Chiavegato G, Marino V, Canetti D, Cozzolino F, Monti M, Pucci P, Mariotto S
    DOI: 10.1042/BCJ20160294

    Signal transducer and activator of transcription 3 (STAT3) is a transcription factor activated by the phosphorylation of tyrosine 705 in response to many cytokines and growth factors. Recently, the roles for unphosphorylated STAT3 (U-STAT3) have been described in response to cytokine stimulation, in cancers, and in the maintenance of heterochromatin stability. It has been reported that U-STAT3 dimerizes, shuttles between the cytoplasm and nucleus, and binds to DNA, thereby driving genes transcription. Although many reports describe the active role of U-STAT3 in oncogenesis in addition to phosphorylated STAT3, the U-STAT3 functional pathway remains elusive.In this report, we describe the molecular mechanism of U-STAT3 dimerization, and we identify the presence of two intermolecular disulfide bridges between Cys367 and Cys542 and Cys418 and Cys426, respectively. Recently, we reported that the same cysteines contribute to the redox regulation of STAT3 signaling pathway both in vitro and in vivo The presence of these disulfides is here demonstrated to largely contribute to the structure and the stability of U-STAT3 dimer as the dimeric form rapidly dissociates upon reduction in the S-S bonds. In particular, the Cys367-Cys542 disulfide bridge is shown to be critical for U-STAT3 DNA-binding activity. Mutation of the two Cys residues completely abolishes the DNA-binding capability of U-STAT3. Spectroscopic investigations confirm that the noncovalent interactions are sufficient for proper folding and dimer formation, but that the interchain disulfide bonds are crucial to preserve the functional dimer. Finally, we propose a reaction scheme of U-STAT3 dimerization with a first common step followed by stabilization through the formation of interchain disulfide bonds.

  • Renal phenotype in Bardet-Biedl syndrome: a combined defect of urinary concentration and dilution is associated with defective urinary AQP2 and UMOD excretion.
    Publication Date: 01/10/2016, on American journal of physiology. Renal physiology
    by Zacchia M, Zacchia E, Zona E, Capolongo G, Raiola I, Rinaldi L, Trepiccione F, Ingrosso D, Perna A, Di Iorio V, Simonelli F, Moe OW, Capasso G
    DOI: 10.1152/ajprenal.00224.2016

    The renal phenotype in Bardet-Biedl syndrome (BBS) is highly variable. The present study describes renal findings in 41 BBS patients and analyzes the pathogenesis of hyposthenuria, the most common renal dysfunction. Five of 41 patients (12%) showed an estimated glomerular filtration rate < 60 ml·min(-1)·1.73 m(-2) Urine protein and urine albumin-to-creatinine ratio were over 200 and 30 mg/g in 9/24 and 7/23 patients, respectively. Four of 41 patients showed no renal anomalies on ultrasound. Twenty of 34 patients had hyposthenuria in the absence of renal insufficiency. In all 8 of the hyposthenuric patients studied, dDAVP failed to elevate urine osmolality (Uosm), suggesting a nephrogenic origin. Interestingly, water loading (WL) did not result in a significant reduction of Uosm, indicating combined concentrating and diluting defects. dDAVP infusion induced a significant increase of plasma Factor VIII and von Willebrand Factor levels, supporting normal function of the type 2 vasopressin receptor at least in endothelial cells. While urinary aquaporin 2 (u-AQP2) abundance was not different between patients and controls at baseline, the dDAVP-induced increased u-AQP2 and the WL-induced reduction of u-AQP2 were blunted in patients with a combined concentrating and diluting defect, suggesting a potential role of AQP2 in the defective regulation of water absorption. Urine Uromodulin excretion was reduced in all hyposthenuric patients, suggesting a thick ascending limb defect. Interestingly, renal Na, Cl, Ca, but not K handling was impaired after acute WL but not at basal. In summary, BBS patients show combined urinary concentration and dilution defects; a thick ascending limb and collecting duct tubulopathy may underlie impaired water handling.

  • Rasagiline for sleep disorders in patients with Parkinson's disease: a prospective observational study.
    Publication Date: 29/09/2016, on Neuropsychiatric disease and treatment
    by Schettino C, Dato C, Capaldo G, Sampaolo S, Di Iorio G, Melone MA
    DOI: 10.2147/NDT.S116476

    Rasagiline is a selective, irreversible monoamine oxidase B inhibitor that ameliorates the symptoms of Parkinson's disease (PD) by inhibiting striatal dopamine metabolism. There is also evidence that monoamine oxidase B inhibitors increase melatonin levels in the pineal gland and may have a beneficial effect on sleep disorders, which are a common feature in patients with PD.

  • Sweeter and stronger: enhancing sweetness and stability of the single chain monellin MNEI through molecular design.
    Publication Date: 23/09/2016, on Scientific reports
    by Leone S, Pica A, Merlino A, Sannino F, Temussi PA, Picone D
    DOI: 10.1038/srep34045

    Sweet proteins are a family of proteins with no structure or sequence homology, able to elicit a sweet sensation in humans through their interaction with the dimeric T1R2-T1R3 sweet receptor. In particular, monellin and its single chain derivative (MNEI) are among the sweetest proteins known to men. Starting from a careful analysis of the surface electrostatic potentials, we have designed new mutants of MNEI with enhanced sweetness. Then, we have included in the most promising variant the stabilising mutation E23Q, obtaining a construct with enhanced performances, which combines extreme sweetness to high, pH-independent, thermal stability. The resulting mutant, with a sweetness threshold of only 0.28 mg/L (25 nM) is the strongest sweetener known to date. All the new proteins have been produced and purified and the structures of the most powerful mutants have been solved by X-ray crystallography. Docking studies have then confirmed the rationale of their interaction with the human sweet receptor, hinting at a previously unpredicted role of plasticity in said interaction.

  • Structural modifications of the serotonin 5-HT7 receptor agonist N-(4-cyanophenylmethyl)-4-(2-biphenyl)-1-piperazinehexanamide (LP-211) to improve in vitro microsomal stability: A case study.
    Publication Date: 14/09/2016, on European journal of medicinal chemistry
    by Lacivita E, Podlewska S, Speranza L, Niso M, Satała G, Perrone R, Perrone-Capano C, Bojarski AJ, Leopoldo M
    DOI: 10.1016/j.ejmech.2016.05.005

    The 5-HT7 serotonin receptor is revealing a promising target for innovative therapeutic strategies of neurodevelopmental and neuropsychiatric disorders. Here, we report the synthesis of thirty long-chain arylpiperazine analogs of the selective and brain penetrant 5-HT7 receptor agonist LP-211 (1) designed to enhance stability towards microsomal oxidative metabolism. Commonly used medicinal chemistry strategies were used (i.e., reduction of overall lipophilicity, introduction of electron-withdrawing groups, blocking of potential vulnerable sites of metabolism), and in vitro microsomal stability was tested. The data showed that the adopted design strategy does not directly translate into improvements in stability. Instead, the metabolic stability of the compounds was related to the presence of specific substituents in well-defined regions of the molecule. The collected data allowed for the construction of a machine learning model that, in a given chemical space, is able to describe and quantitatively predict the metabolic stability of the compounds. The majority of the synthesized compounds maintained high affinity for 5-HT7 receptors and showed selectivity towards 5-HT6 and dopamine D2 receptors and different selectivity for 5-HT1A and α1 adrenergic receptors. Compound 50 showed 3-fold higher in vitro stability towards oxidative metabolism than 1 and was able to stimulate neurite outgrowth in neuronal primary cultures through the 5-HT7 receptor in a shorter time and at a lower concentration than the agonist 1. A preliminary disposition study in mice revealed that compound 50 was metabolically stable and was able to pass the blood-brain barrier, thus representing a new tool for studying the pharmacotherapeutic potential of 5-HT7 receptor in vivo.

  • Effects of low-carbohydrate diet therapy in overweight subjects with autoimmune thyroiditis: possible synergism with ChREBP.
    Publication Date: 14/09/2016, on Drug design, development and therapy
    by Esposito T, Lobaccaro JM, Esposito MG, Monda V, Messina A, Paolisso G, Varriale B, Monda M, Messina G
    DOI: 10.2147/DDDT.S106440

    The thyroid is one of the metabolism regulating glands. Its function is to determine the amount of calories that the body has to burn to maintain normal weight. Thyroiditides are inflammatory processes that mainly result in autoimmune diseases. We have conducted the present study in order to have a clear picture of both autoimmune status and the control of body weight. We have evaluated the amount of either thyroid hormones, or antithyroid, or anti-microsomal, or anti-peroxidase antibodies (Abs) in patients with high amounts of Abs. In a diet devoid of carbohydrates (bread, pasta, fruit, and rice), free from goitrogenic food, and based on body mass index, the distribution of body mass and intracellular and extracellular water conducted for 3 weeks gives the following results: patients treated as above showed a significant reduction of antithyroid (-40%, P<0.013), anti-microsomal (-57%, P<0.003), and anti-peroxidase (-44%, P<0,029) Abs. Untreated patients had a significant increase in antithyroid (+9%, P<0.017) and anti-microsomal (+30%, P<0.028) Abs. Even the level of anti-peroxidase Abs increased without reaching statistical significance (+16%, P>0064). With regard to the body parameters measured in patients who followed this diet, reduction in body weight (-5%, P<0.000) and body mass index (-4%, P<0.000) were observed. Since 83% of patients with high levels of autoantibodies are breath test positive to lactase with a lactase deficit higher than 50%, this fact led us to hypothesize a correlation with carbohydrate-responsive element-binding protein and therefore a possible role of carbohydrate metabolism in the development and maintenance of autoimmune thyroiditis associated with body weight increase and slower basic metabolism.

  • Convergent Effects of Resveratrol and PYK2 on Prostate Cells.
    Publication Date: 13/09/2016, on International journal of molecular sciences
    by Conte A, Kisslinger A, Procaccini C, Paladino S, Oliviero O, de Amicis F, Faicchia D, Fasano D, Caputo M, Matarese G, Pierantoni GM, Tramontano D
    DOI: 10.3390/ijms17091542

    Resveratrol, a dietary polyphenol, is under consideration as chemopreventive and chemotherapeutic agent for several diseases, including cancer. However, its mechanisms of action and its effects on non-tumor cells, fundamental to understand its real efficacy as chemopreventive agent, remain largely unknown. Proline-rich tyrosine kinase 2 (PYK2), a non-receptor tyrosine kinase acting as signaling mediator of different stimuli, behaves as tumor-suppressor in prostate. Since, PYK2 and RSV share several fields of interaction, including oxidative stress, we have investigated their functional relationship in human non-transformed prostate EPN cells and in their tumor-prone counterpart EPN-PKM, expressing a PYK2 dead-kinase mutant. We show that RSV has a strong biological activity in both cell lines, decreasing ROS production, inducing morphological changes and reversible growth arrest, and activating autophagy but not apoptosis. Interestingly, the PYK2 mutant increases basal ROS and autophagy levels, and modulates the intensity of RSV effects. In particular, the anti-oxidant effect of RSV is more potent in EPN than in EPN-PKM, whereas its anti-proliferative and pro-autophagic effects are more significant in EPN-PKM. Consistently, PYK2 depletion by RNAi replicates the effects of the PKM mutant. Taken together, our results reveal that PYK2 and RSV act on common cellular pathways and suggest that RSV effects on prostate cells may depend on mutational-state or expression levels of PYK2 that emerges as a possible mediator of RSV mechanisms of action. Moreover, the observation that resveratrol effects are reversible and not associated to apoptosis in tumor-prone EPN-PKM cells suggests caution for its use in humans.

  • Positively charged polymers modulate the fate of human mesenchymal stromal cells via ephrinB2/EphB4 signaling.
    Publication Date: 01/09/2016, on Stem cell research
    by De Luca I, Di Salle A, Alessio N, Margarucci S, Simeone M, Galderisi U, Calarco A, Peluso G
    DOI: 10.1016/j.scr.2016.07.005

    Understanding the mechanisms by which mesenchymal stromal cells (MSCs) interact with the physical properties (e.g. topography, charge, ζ-potential, and contact angle) of polymeric surfaces is essential to design new biomaterials capable of regulating stem cell behavior. The present study investigated the ability of two polymers (pHM1 and pHM3) with different positive surface charge densities to modulate the differentiation of MSCs into osteoblast-like phenotype via cell-cell ephrinB2/EphB4 signaling. Although pHM1 promoted the phosphorylation of EphB4, leading to cell differentiation, pHM3, characterized by a high positive surface charge density, had no significant effect on EphB4 activation or MSCs differentiation. When the MSCs were cultured on pHM1 in the presence of a forward signaling blocking peptide, the osteoblast differentiation was compromised. Our results demonstrated that the ephrinB2/EphB4 interaction was required for MSCs differentiation into an osteoblast-like phenotype and that the presence of a high positive surface charge density altered this interaction.

  • Beyond peripheral nerve injury: spinal gliopathy and maladaptive synaptic plasticity.
    Publication Date: 01/09/2016, on Neural regeneration research
    by Cirillo G, Papa M
    DOI: 10.4103/1673-5374.191214

  • The Role of Cathepsin D in the Pathogenesis of Human Neurodegenerative Disorders.
    Publication Date: 01/09/2016, on Medicinal research reviews
    by Vidoni C, Follo C, Savino M, Melone MA, Isidoro C
    DOI: 10.1002/med.21394

    In familial neurodegenerative disorders, protein aggregates form continuously because of genetic mutations that drive the synthesis of truncated or unfolded proteins. The oxidative stress imposed by neurotransmitters and environmental neurotoxins constitutes an additional threat to the folding of the proteins and the integrity of organelle membranes in neurons. Failure in degrading such altered materials compromises the function of neurons and eventually leads to neurodegeneration. The lysosomal proteolytic enzyme Cathepsin D is the only aspartic-type protease ubiquitously expressed in all the cells of the human body, and it is expressed at high level in the brain. In general, cathepsin D mediated proteolysis is essential to neuronal cell homeostasis through the degradation of unfolded or oxidized protein aggregates delivered to lysosomes via autophagy or endocytosis. More specifically, many altered neuronal proteins that hallmark neurodegenerative diseases (e.g., the amyloid precursor, α-synuclein, and huntingtin) are physiologic substrates of cathepsin D and would abnormally accumulate if not efficiently degraded by this enzyme. Furthermore, experimental evidence indicates that cathepsin D activity is linked to the metabolism of cholesterol and of glycosaminoglycans, which accounts for its involvement in neuronal plasticity. This review focuses on the unique role of cathepsin D mediated proteolysis in the pathogenesis of human neurodegenerative diseases.