Neural stem cells from a mouse model of Rett syndrome are prone to senescence, show reduced capacity to cope with genotoxic stress, and are impaired in the differentiation process.
Publication Date: 22/03/2018, on Experimental & molecular medicine
by Alessio N, Riccitiello F, Squillaro T, Capasso S, Del Gaudio S, Di Bernardo G, Cipollaro M, Melone MAB, Peluso G, Galderisi U
Several aspects of stem cell life are governed by epigenetic variations, such as DNA methylation, histone modifications, and chromatin remodeling. Epigenetic events are also connected with the impairment of stem cell functions. For example, during senescence, there are significant changes in chromatin organization that alter transcription. The MECP2 protein can bind methylated cytosines and contribute to regulating gene expression at one of the highest hierarchical levels. Researchers are particularly interested in this protein, as up to 90% of Rett syndrome patients have an MECP2 gene mutation. Nevertheless, the role of MECP2 in this disease remains poorly understood. We used a mouse model of Rett syndrome to evaluate whether residual MECP2 activity in neural stem cells (NSCs) induced the senescence phenomena that could affect stem cell function. Our study clearly demonstrated that the reduced expression of MECP2 is connected with an increase in senescence, an impairment in proliferation capacity, and an accumulation of unrepaired DNA foci. Mecp2 NSCs did not cope with genotoxic stress in the same way as the control cells did. Indeed, after treatment with different DNA-damaging agents, the NSCs from mice with mutated Mecp2 accumulated more DNA damage foci (γ-H2AX+) and were more prone to cell death than the controls. Senescence in Mecp2 NSCs decreased the number of stem cells and progenitors and gave rise to a high percentage of cells that expressed neither stem/progenitor nor differentiation markers. These cells could be senescent and dysfunctional.
Are ultra-short heart rate variability features good surrogates of short-term ones? State-of-the-art review and recommendations.
Publication Date: 14/03/2018, on Healthcare technology letters
by Pecchia L, Castaldo R, Montesinos L, Melillo P
Ultra-short heart rate variability (HRV) analysis refers to the study of HRV features in excerpts of length <5 min. Ultra-short HRV is widely growing in many healthcare applications for monitoring individual's health and well-being status, especially in combination with wearable sensors, mobile phones, and smart-watches. Long-term (nominally 24 h) and short-term (nominally 5 min) HRV features have been widely investigated, physiologically justified and clear guidelines for analysing HRV in 5 min or 24 h are available. Conversely, the reliability of ultra-short HRV features remains unclear and many investigations have adopted ultra-short HRV analysis without questioning its validity. This is partially due to the lack of accepted algorithms guiding investigators to systematically assess ultra-short HRV reliability. This Letter critically reviewed the existing literature, aiming to identify the most suitable algorithms, and harmonise them to suggest a standard protocol that scholars may use as a reference in future studies. The results of the literature review were surprising, because, among the 29 reviewed papers, only one paper used a rigorous method, whereas the others employed methods that were partially or completely unreliable due to the incorrect use of statistical tests. This Letter provides recommendations on how to assess ultra-short HRV features reliably and proposes an inclusive algorithm that summarises the state-of-the-art knowledge in this area.
Synthesis and Biological Evaluation of a New Structural Simplified Analogue of cADPR, a Calcium-Mobilizing Secondary Messenger Firstly Isolated from Sea Urchin Eggs.
Publication Date: 10/03/2018, on Marine drugs
by D'Errico S, Borbone N, Catalanotti B, Secondo A, Petrozziello T, Piccialli I, Pannaccione A, Costantino V, Mayol L, Piccialli G, Oliviero G
Herein, we reported on the synthesis of cpIPP, which is a new structurally-reduced analogue of cyclic ADP-ribose (cADPR), a potent Ca-releasing secondary messenger that was firstly isolated from sea urchin eggs extracts. To obtain cpIPP the "northern" ribose of cADPR was replaced by a pentyl chain and the pyrophosphate moiety by a phophono-phosphate anhydride. The effect of the presence of the new phosphono-phosphate bridge on the intracellular Ca release induced by cpIPP was assessed in PC12 neuronal cells in comparison with the effect of the pyrophosphate bridge of the structurally related cyclic N1-butylinosine diphosphate analogue (cbIDP), which was previously synthesized in our laboratories, and with that of the linear precursor of cpIPP, which, unexpectedly, revealed to be the only one provided with Ca release properties.
Differentiation by nerve growth factor (NGF) involves mechanisms of crosstalk between energy homeostasis and mitochondrial remodeling.
Publication Date: 09/03/2018, on Cell death & disease
by Martorana F, Gaglio D, Bianco MR, Aprea F, Virtuoso A, Bonanomi M, Alberghina L, Papa M, Colangelo AM
Neuronal differentiation involves extensive modification of biochemical and morphological properties to meet novel functional requirements. Reorganization of the mitochondrial network to match the higher energy demand plays a pivotal role in this process. Mechanisms of neuronal differentiation in response to nerve growth factor (NGF) have been largely characterized in terms of signaling, however, little is known about its impact on mitochondrial remodeling and metabolic function. In this work, we show that NGF-induced differentiation requires the activation of autophagy mediated by Atg9b and Ambra1, as it is disrupted by their genetic knockdown and by autophagy blockers. NGF differentiation involves the induction of P-AMPK and P-CaMK, and is prevented by their pharmacological inhibition. These molecular events correlate with modifications of energy and redox homeostasis, as determined by ATP and NADPH changes, higher oxygen consumption (OCR) and ROS production. Our data indicate that autophagy aims to clear out exhausted mitochondria, as determined by enhanced localization of p62 and Lysotracker-red to mitochondria. In addition, we newly demonstrate that NGF differentiation is accompanied by increased mitochondrial remodeling involving higher levels of fission (P-Drp1) and fusion proteins (Opa1 and Mfn2), as well as induction of Sirt3 and the transcription factors mtTFA and PPARγ, which regulate mitochondria biogenesis and metabolism to sustain increased mitochondrial mass, potential, and bioenergetics. Overall, our data indicate a new NGF-dependent mechanism involving mitophagy and extensive mitochondrial remodeling, which plays a key role in both neurogenesis and nerve regeneration.
Huntingtin protein: A new option for fixing the Huntington's disease countdown clock.
Publication Date: 08/03/2018, on Neuropharmacology
by Caterino M, Squillaro T, Montesarchio D, Giordano A, Giancola C, Melone MAB
Huntington's disease is a dreadful, incurable disorder. It springs from the autosomal dominant mutation in the first exon of the HTT gene, which encodes for the huntingtin protein (HTT) and results in progressive neurodegeneration. Thus far, all the attempted approaches to tackle the mutant HTT-induced toxicity causing this disease have failed. The mutant protein comes with the aberrantly expanded poly-glutamine tract. It is primarily to blame for the build-up of β-amyloid-like HTT aggregates, deleterious once broadened beyond the critical ∼35-37 repeats threshold. Recent experimental findings have provided valuable information on the molecular basis underlying this HTT-driven neurodegeneration. These findings indicate that the poly-glutamine siding regions and many post-translation modifications either abet or counter the poly-glutamine tract. This review provides an overall, up-to-date insight into HTT biophysics and structural biology, particularly discussing novel pharmacological options to specifically target the mutated protein and thus inhibit its functions and toxicity.
Alteration of endosomal trafficking is associated with early-onset parkinsonism caused by SYNJ1 mutations.
Publication Date: 07/03/2018, on Cell death & disease
by Fasano D, Parisi S, Pierantoni GM, De Rosa A, Picillo M, Amodio G, Pellecchia MT, Barone P, Moltedo O, Bonifati V, De Michele G, Nitsch L, Remondelli P, Criscuolo C, Paladino S
Recently, a new form of autosomal recessive early-onset parkinsonism (PARK20), due to mutations in the gene encoding the phosphoinositide phosphatase, Synaptojanin 1 (Synj1), has been reported. Several genes responsible for hereditary forms of Parkinson's disease are implicated in distinct steps of the endolysosomal pathway. However, the nature and the degree of endocytic membrane trafficking impairment in early-onset parkinsonism remains elusive. Here, we show that depletion of Synj1 causes drastic alterations of early endosomes, which become enlarged and more numerous, while it does not affect the morphology of late endosomes both in non-neuronal and neuronal cells. Moreover, Synj1 loss impairs the recycling of transferrin, while it does not alter the trafficking of the epidermal growth factor receptor. The ectopic expression of Synj1 restores the functions of early endosomes, and rescues these trafficking defects in depleted cells. Importantly, the same alterations of early endosomal compartments and trafficking defects occur in fibroblasts of PARK20 patients. Our data indicate that Synj1 plays a crucial role in regulating the homeostasis and functions of early endosomal compartments in different cell types, and highlight defective cellular pathways in PARK20. In addition, they strengthen the link between endosomal trafficking and Parkinson's disease.
Prevalent use of combined prophylaxis of hepatitis B after liver transplantation in Italy: results of a national survey in a large cohort.
Publication Date: 01/03/2018, on Minerva gastroenterologica e dietologica
by Marzano A, Andreone P, Boccagni P, Burra P, Caneschi F, Conoscitore PF, Coppola C, DE Carlis L, Fagiuoli S, Forte P, Gaeta GB, Iemmolo RM, Lotti Suffredini A, Mazzola M, Merli M, Parrilli G, Piai G, Piras MR, Salizzoni M, Tamè M, Tisone G, Toniutto P, Vennarecci G, Volpes R, Zamboni F, Caccamo L,
Prophylaxis of hepatitis B after liver transplantation with antiviral(s) and immunoglobulins efficiently protect the majority of recipients; however recent experiences suggest a decline of HBsAg-positive candidates and the use of hepatitis B Immunoglobulin-free schedules.
Visual Cortex Activation in Patients With Stargardt Disease.
Publication Date: 01/03/2018, on Investigative ophthalmology & visual science
by Melillo P, Prinster A, Di Iorio V, Olivo G, D'Alterio FM, Cocozza S, Orrico A, Quarantelli M, Testa F, Brunetti A, Simonelli F
Primary visual cortex (PVC) contains a retinotopic map in which the central visual field (CVF) is highly magnified compared to the peripheral field. Several studies have used functional magnetic resonance imaging (fMRI) in patients with macular degeneration to assess the reorganization of visual processing in relationship with the development of extrafoveal preferred retinal locus (PRL). We evaluated the functional response in PVC and its correlation with retinal parameters in patients with Stargardt disease due to ABCA4 mutations (STGD1).
S-glutathionylation exerts opposing roles in the regulation of STAT1 and STAT3 signaling in reactive microglia.
Publication Date: 01/03/2018, on Free radical biology & medicine
by Butturini E, Cozzolino F, Boriero D, Carcereri de Prati A, Monti M, Rossin M, Canetti D, Cellini B, Pucci P, Mariotto S
STAT1 and STAT3 are two transcription factors involved in a lot of cellular functions such as immune response, proliferation, apoptosis, and cell survival. A number of literature evidences described a yin-yang relationship between activation of STAT1 and STAT3 in neurodegenerative disorders where STAT1 exerts a pro-apoptotic effect whereas STAT3 shows neuroprotective properties through the inhibition of apoptosis. Although the role of oxidative-stress in the pathogenesis of neurodegeneration is clearly described, its influence in the regulation of these pathways is poorly understood. Herein, we demonstrate that HO rapidly induces phosphorylation of STAT1 whereas it is not able to influence phosphorylation of STAT3 in mouse microglia BV2 cells. The analysis of the molecular mechanism of STATs signaling reveals that HO induces S-glutathionylation of both STAT1 and STAT3. The same post-translational event exerts an opposing role in the regulation of STAT1 and STAT3 signaling. These data not only confirm redox sensibility of STAT3 signaling but also reveal for the first time that STAT1 is susceptible to redox regulation. A deep study of the molecular mechanism of STAT1 redox regulation, identifies Cys324 and Cys492 as the main targets of S-glutathionylation and confirms that S-glutathionylation does not impair JAK2 mediated STAT1 tyrosine phosphorylation. These results demonstrate that both phosphorylation and glutathionylation contribute to activation of STAT1 during oxidative stress and underline that the same post-translation event exerts an opposing role in the regulation of STAT1 and STAT3 signaling in microglia cells.
Successful long-term therapy with flecainide in a family with paramyotonia congenita.
Publication Date: 27/02/2018, on Journal of neurology, neurosurgery, and psychiatry
by Terracciano C, Farina O, Esposito T, Lombardi L, Napolitano F, De Blasiis P, Ciccone G, Todisco V, Tuccillo F, Bernardini S, Di Iorio G, Melone MAB, Sampaolo S
Tissue-specific and mosaic imprinting defects underlie opposite congenital growth disorders in mice.
Publication Date: 22/02/2018, on PLoS genetics
by Freschi A, Hur SK, Valente FM, Ideraabdullah FY, Sparago A, Gentile MT, Oneglia A, Di Nucci D, Colucci-D'Amato L, Thorvaldsen JL, Bartolomei MS, Riccio A, Cerrato F
Differential DNA methylation defects of H19/IGF2 are associated with congenital growth disorders characterized by opposite clinical pictures. Due to structural differences between human and mouse, the mechanisms by which mutations of the H19/IGF2 Imprinting Control region (IC1) result in these diseases are undefined. To address this issue, we previously generated a mouse line carrying a humanized IC1 (hIC1) and now replaced the wildtype with a mutant IC1 identified in the overgrowth-associated Beckwith-Wiedemann syndrome. The new humanized mouse line shows pre/post-natal overgrowth on maternal transmission and pre/post-natal undergrowth on paternal transmission of the mutation. The mutant hIC1 acquires abnormal methylation during development causing opposite H19/Igf2 imprinting defects on maternal and paternal chromosomes. Differential and possibly mosaic Igf2 expression and imprinting is associated with asymmetric growth of bilateral organs. Furthermore, tissue-specific imprinting defects result in deficient liver- and placenta-derived Igf2 on paternal transmission and excessive Igf2 in peripheral tissues on maternal transmission, providing a possible molecular explanation for imprinting-associated and phenotypically contrasting growth disorders.
Increase of natural killer cells in children with liver transplantation-acquired food allergy.
Publication Date: 15/02/2018, on Allergologia et immunopathologia
by Mori F, Angelucci C, Cianferoni A, Barni S, Indolfi G, Casini A, Mangone G, Materassi M, Pucci N, Azzari C, Novembre E
Transplantation-acquired food allergies (TAFA) are frequently reported and considered to be caused by immunosuppressive therapy. The aim of this study was to investigate the allergic and immunologic responses in children who had liver or kidney transplantations.
Effects of different extracts of curcumin on TPC1 papillary thyroid cancer cell line.
Publication Date: 15/02/2018, on BMC complementary and alternative medicine
by Perna A, De Luca A, Adelfi L, Pasquale T, Varriale B, Esposito T
The thyroid gland is one of the largest endocrine glands in the body. The vast majority of TCs (> 90%) originate from follicular cells and are defined as differentiated thyroid cancers (DTC) and the two histological subtypes are the papillary TC with its variants and the follicular TC. Curcumin possesses a wide variety of biological functions, and thanks to its properties, it has gained considerable attention due to its profound medicinal values (Prasad, Gupta, Tyagi, and Aggarwal, Biotechnol Adv 32:1053-1064, 2014). We have undertaken the present work in order to define the possible role of curcumin in modulating the genetic expression of cell markers and to understand the effectiveness of this nutraceutical in modulating the regression of cancer phenotype.
The carnitine system and cancer metabolic plasticity.
Publication Date: 14/02/2018, on Cell death & disease
by Melone MAB, Valentino A, Margarucci S, Galderisi U, Giordano A, Peluso G
Metabolic flexibility describes the ability of cells to respond or adapt its metabolism to support and enable rapid proliferation, continuous growth, and survival in hostile conditions. This dynamic character of the cellular metabolic network appears enhanced in cancer cells, in order to increase the adaptive phenotype and to maintain both viability and uncontrolled proliferation. Cancer cells can reprogram their metabolism to satisfy the energy as well as the biosynthetic intermediate request and to preserve their integrity from the harsh and hypoxic environment. Although several studies now recognize these reprogrammed activities as hallmarks of cancer, it remains unclear which are the pathways involved in regulating metabolic plasticity. Recent findings have suggested that carnitine system (CS) could be considered as a gridlock to finely trigger the metabolic flexibility of cancer cells. Indeed, the components of this system are involved in the bi-directional transport of acyl moieties from cytosol to mitochondria and vice versa, thus playing a fundamental role in tuning the switch between the glucose and fatty acid metabolism. Therefore, the CS regulation, at both enzymatic and epigenetic levels, plays a pivotal role in tumors, suggesting new druggable pathways for prevention and treatment of human cancer.
Brain Metabolic DNA in Rat Cytoplasm.
Publication Date: 09/02/2018, on Molecular neurobiology
by Giuditta A, Rutigliano B
Brain metabolic DNA (BMD) is not involved in cell division or DNA repair but is modulated by memory acquisition, sleep processing, and circadian oscillations. Using routine methods of subcellular fractionation, newly synthesized BMD from male rats is shown to be localized in crude nuclear, mitochondrial, and microsomal fractions and in two fractions of purified nuclei. Sub-fractionation of the mitochondrial fraction indicates the prevalent localization of BMD in free mitochondria and to a lesser degree in synaptosomes and myelin. Cesium density profiles of homogenate, subcellular fractions, and purified nuclei obtained after incorporation periods from 30 min to 4 h indicate that BMD synthesis takes place by reverse transcription in cytoplasmic organelles. Following the acquisition of the double-stranded structure, BMD is transferred to nuclei. Kinetic analyses lasting several weeks highlight the massive BMD turnover in subcellular fractions and purified nuclei and its dependence on age. Data are in agreement with the role of BMD as a temporary information store of cell responses of potential use in comparable forthcoming experiences.