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Motor neuron diseases (MNDs) are neurodegenerative disorders characterized by upper and/or lower MN loss. MNDs include amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and spinal and bulbar muscular atrophy (SBMA). Despite variability in onset, progression, and genetics, they share a common skeletal muscle involvement, suggesting that it could be a primary site for MND pathogenesis. Due to the key role of muscle-specific microRNAs (myomiRs) in skeletal muscle development, by real-time PCR we investigated the expression of miR-206, miR-133a, miR-133b, and miR-1, and their target genes, in G93A-SOD1 ALS, ∆7SMA, and KI-SBMA mouse muscle during disease progression. Further, we analyzed their expression in serum of SOD1-mutated ALS, SMA, and SBMA patients, to demonstrate myomiR role as noninvasive biomarkers. Our data showed a dysregulation of myomiRs and their targets, in ALS, SMA, and SBMA mice, revealing a common pathogenic feature associated with muscle impairment. A similar myomiR signature was observed in patients’ sera. In particular, an up-regulation of miR-206 was identified in both mouse muscle and serum of human patients. Our overall findings highlight the role of myomiRs as promising biomarkers in ALS, SMA, and SBMA. Further investigations are needed to explore the potential of myomiRs as therapeutic targets for MND treatment.

According to the Centre for Disease Control and Prevention in 2020, a cluster of pneumonia cases of unknown etiology caused by the severe acute respiratory syndrome (SARS)-coronavirus 2 was reported in Wuhan, China. The present review examined the literature to reveal the incidence of novel coronavirus-2019 disease (COVID-19) infections, underlying comorbidities, workplace infections and case fatality rates. A review was performed to identify the relevant publications available up to May 15, 2020. Since the early stages of the COVID-19 outbreak, the case fatality rate among healthcare workers (HCWs) has stood at 0.69% worldwide and 0.4% in Italy. Based on the current information, most patients have exhibited good prognoses in terms of after-effects or sequelae and low mortality rate. Patients that became critically ill were primarily in the elderly population or had chronic underlying diseases, including diabetes and hypertension. Among all working sectors, HCWs, since they are front-line caregivers for patients with COVID-19, are considered to be in the high-risk population. Increased age and a number of comorbidity factors have been associated with increased risk of mortality in patients with COVID-19. The most frequent complications of COVID-19 reported that can cause fatality in patients were SARS, cardiac arrest, secondary infections and septic shock, in addition to acute kidney failure and liver failure. Overcoming the COVID-19 pandemic is an ongoing challenge, which poses a threat to global health that requires close surveillance and prompt diagnosis, in coordination with research efforts to understand this pathogen and develop effective countermeasures.

This study consists of determining the physical vulnerability of the region of São Miguel do Gostoso and Pedra Grande (in northeastern Brazil) before and after wind farm installation. To perform such an investigation, an analysis of the coastline vulnerability of the aforementioned area was conducted, considering changes occurred in the past 30 years and spatially presented separately. The Natural Vulnerability Index (NVI) and Environmental Vulnerability Index (EVI) were calculated through analysis using thematic maps of geomorphology, geology, soils, vegetation, and land use and occupation variables, with their dimensionality and subjectivity determined by the execution of the hierarchical analytical process (HAP) and principal component analysis (PCA). High and very high vulnerability together showed proportions between 18 and 30% in all NVI and EVI scenarios. The Coastal Vulnerability Index (CVI) was defined using two methodologies for the three scenarios of sea level rise established by the Intergovernmental Panel on Climate Change (IPCC): the first one includes six physical or hydrodynamic variables, and the second includes, beyond these, three more variables of anthropogenic action. In all of the applied scenarios, the medium and high vulnerabilities dominated all along the coastline, with the second method being the most optimistic. We can conclude that the installation of the wind farm complex contributed to the increase of the vulnerability of the local ecosystems regarding the three investigated indices; however, it was not the preponderant factor for the determination of the CVI vulnerability degree., Este estudo visa à determinação da vulnerabilidade física e ambiental da zona costeira de São Miguel do Gostoso e Pedra Grande/RN antes e depois da instalação de parques eólicos. Além disso, é realizada uma análise de vulnerabilidade na linha de costa da área mencionada, levando-se em consideração as alterações espaciais concretizadas nos últimos 30 anos, análise esta que é apresentada separadamente. Calcularam-se os índices de vulnerabilidade natural (IVN) e ambiental (IVA) por meio de análises espaciais baseadas em mapas temáticos das variáveis do meio físico e antrópico, conforme métodos de análise multicritérios hierarquizada e de redução de dimensionalidade por processo analítico hierárquico (PAH) e pela análise de componentes principais (ACP). As vulnerabilidades alta e muito alta, somadas, apresentaram proporções entre 18 e 30% em todos os cenários do IVN e IVA. O índice de vulnerabilidade costeira (IVC) foi definido por dois métodos para três cenários de aumento do nível do mar estabelecidos pelo Painel Intergovernamental de Mudanças Climáticas (IPCC): um com seis variáveis físicas e hidrodinâmicas, e outro que inclui, além destas, outras três variáveis de ação antrópica. Para todos os cenários, toda a extensão da linha de costa mostrase, majoritariamente, com vulnerabilidades média e alta. Conclui-se que a implantação do complexo de parques eólicos contribuiu para o aumento da vulnerabilidade dos ecossistemas locais nos três índices avaliados, mas não foi o fator preponderante para a definição do grau de vulnerabilidade do IVC.

This study consists of determining the physical vulnerability of the region of São Miguel do Gostoso and Pedra Grande (in northeastern Brazil) before and after wind farm installation. To perform such an investigation, an analysis of the coastline vulnerability of the aforementioned area was conducted, considering changes occurred in the past 30 years and spatially presented separately. The Natural Vulnerability Index (NVI) and Environmental Vulnerability Index (EVI) were calculated through analysis using thematic maps of geomorphology, geology, soils, vegetation, and land use and occupation variables, with their dimensionality and subjectivity determined by the execution of the hierarchical analytical process (HAP) and principal component analysis (PCA). High and very high vulnerability together showed proportions between 18 and 30% in all NVI and EVI scenarios. The Coastal Vulnerability Index (CVI) was defined using two methodologies for the three scenarios of sea level rise established by the Intergovernmental Panel on Climate Change (IPCC): the first one includes six physical or hydrodynamic variables, and the second includes, beyond these, three more variables of anthropogenic action. In all of the applied scenarios, the medium and high vulnerabilities dominated all along the coastline, with the second method being the most optimistic. We can conclude that the installation of the wind farm complex contributed to the increase of the vulnerability of the local ecosystems regarding the three investigated indices; however, it was not the preponderant factor for the determination of the CVI vulnerability degree., Este estudo visa à determinação da vulnerabilidade física e ambiental da zona costeira de São Miguel do Gostoso e Pedra Grande/RN antes e depois da instalação de parques eólicos. Além disso, é realizada uma análise de vulnerabilidade na linha de costa da área mencionada, levando-se em consideração as alterações espaciais concretizadas nos últimos 30 anos, análise esta que é apresentada separadamente. Calcularam-se os índices de vulnerabilidade natural (IVN) e ambiental (IVA) por meio de análises espaciais baseadas em mapas temáticos das variáveis do meio físico e antrópico, conforme métodos de análise multicritérios hierarquizada e de redução de dimensionalidade por processo analítico hierárquico (PAH) e pela análise de componentes principais (ACP). As vulnerabilidades alta e muito alta, somadas, apresentaram proporções entre 18 e 30% em todos os cenários do IVN e IVA. O índice de vulnerabilidade costeira (IVC) foi definido por dois métodos para três cenários de aumento do nível do mar estabelecidos pelo Painel Intergovernamental de Mudanças Climáticas (IPCC): um com seis variáveis físicas e hidrodinâmicas, e outro que inclui, além destas, outras três variáveis de ação antrópica. Para todos os cenários, toda a extensão da linha de costa mostrase, majoritariamente, com vulnerabilidades média e alta. Conclui-se que a implantação do complexo de parques eólicos contribuiu para o aumento da vulnerabilidade dos ecossistemas locais nos três índices avaliados, mas não foi o fator preponderante para a definição do grau de vulnerabilidade do IVC.

Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by mutations in survival motor neuron (SMN) 1 gene, resulting in a truncatedSMNprotein responsible for degeneration of brain stem and spinal motor neurons. The paralogous SMN2 gene partially compensates full-length SMNprotein production, mitigating the phenotype. Antisense oligonucleotide nusinersen (Spinraza®) enhances SMN2 gene expression. SMN is involved in RNA metabolism and biogenesis of microRNA (miRNA), key gene expression modulators, whose dysregulation contributes to neuromuscular diseases. They are stable in body fluids and may reflect distinct pathophysiological states, thus acting as promising biomarkers. Muscle-specific miRNAs (myomiRs) as biomarkers for clinical use in SMA have not been investigated yet. Here, we analyzed the expression of miR-133a, -133b, -206 and -1, in serum of 21 infantile SMA patients at baseline and after 6 months of nusinersen treatment, and correlated molecular data with response to therapy evaluated by the Hammersmith Functional Motor Scale Expanded (HFMSE). Our results demonstrate that myomiR serological levels decrease over disease course upon nusinersen treatment. Notably, miR-133a reduction predicted patients' response to therapy. Our findings identify myomiRs as potential biomarkers to monitor disease progression and therapeutic response in SMA patients.

Glucose transporter type 1 deficiency syndrome (Glut1 DS) is a rare neurological disorder caused by impaired glucose delivery to the brain. The clinical spectrum of Glut1 DS mainly includes epilepsy, paroxysmal dyskinesia (PD), developmental delay and microcephaly. Glut1 DS diagnosis is based on the identification of hypoglycorrhachia and pathogenic mutations of the SLC2A1 gene. Here, we report the molecular screening of SLC2A1 in 354 patients clinically suspected for Glut1 DS. From this cohort, we selected 245 patients for whom comprehensive clinical and laboratory data were available. Among them, we identified 19 patients carrying nucleotide variants of pathological significance, 5 of which were novel. The symptoms of onset, which varied from neonatal to adult age, included epilepsy, PD or non-epileptic paroxysmal manifestations. The comparison of the clinical features between the 19 SLC2A1 mutated and the 226 non-mutated patients revealed that the onset of epilepsy within the first year of life (when associated with developmental delay or other neurological manifestations), the association of epilepsy with PD and acquired microcephaly are more common in mutated subjects. Taken together, these data confirm the variability of expression of the phenotypes associated with mutation of SLC2A1 and provide useful clinical tools for the early identification of subjects highly suspected for the disease

A new patient with severe mucopolysaccharidosis (MPS) type VII is reported. Non-immune hydrops fetalis (NIHF) was diagnosed during pregnancy. At birth, he showed generalized hydrops and dysmorphic features typical of MPS. Many diagnoses were excluded before reaching the diagnosis of MPS VII at 8 months of life. During the first year of life he had frequent respiratory infections associated with restrictive and obstructive bronchopneumopathy and underwent three surgical interventions: decompression of the spinal cord at the craniocervical junction, bilateral inguinal hernia, and bilateral clubfoot. At 14 months of life he underwent successful haematopoietic cell transplantation (HCT). During the following 10 months, his bronchopneumopathy progressively worsened, needing chronic pharmacological treatment and O2 administration. The patient died of respiratory insufficiency during a respiratory syncytial virus infection at 25 months of age. Molecular analysis showed the homozygous variant c.1617C > T, leading to the synonymous mutation p.Ser539=. This caused aberrant splicing with partial skipping of exon 10 (r.1616-1653del38) and complete skipping of exon 9 (r.1392-1476del85; r.1616-1653del38). No transcript of normal size was evident. The parents were both confirmed to be carriers. In a subsequent pregnancy, a prenatal diagnosis showed an affected fetus. Ultrasound examination before abortion showed NIHF. The skin and placenta examination by electron microscopy showed foamy intracytoplasmic vacuoles with a weakly electron-dense substrate. MPS VII is a very rare disease but it is possible that some cases go undiagnosed for several reasons, including that MPS VII, and other lysosomal storage diseases, are not included in the work-up for NIHF in many institutions, and the presence of anasarca at birth may be confounding for the recognition of the typical facial characteristics of the disease. This is the eighth patient affected by MPS VII who has undergone HCT. It is not

A new patient with severe mucopolysaccharidosis (MPS) type VII is reported. Non-immune hydrops fetalis (NIHF) was diagnosed during pregnancy. At birth, he showed generalized hydrops and dysmorphic features typical of MPS. Many diagnoses were excluded before reaching the diagnosis of MPS VII at 8 months of life. During the first year of life he had frequent respiratory infections associated with restrictive and obstructive bronchopneumopathy and underwent three surgical interventions: decompression of the spinal cord at the craniocervical junction, bilateral inguinal hernia, and bilateral clubfoot. At 14 months of life he underwent successful haematopoietic cell transplantation (HCT). During the following 10 months, his bronchopneumopathy progressively worsened, needing chronic pharmacological treatment and O2 administration. The patient died of respiratory insufficiency during a respiratory syncytial virus infection at 25 months of age. Molecular analysis showed the homozygous variant c.1617C > T, leading to the synonymous mutation p.Ser539=. This caused aberrant splicing with partial skipping of exon 10 (r.1616-1653del38) and complete skipping of exon 9 (r.1392-1476del85; r.1616-1653del38). No transcript of normal size was evident. The parents were both confirmed to be carriers. In a subsequent pregnancy, a prenatal diagnosis showed an affected fetus. Ultrasound examination before abortion showed NIHF. The skin and placenta examination by electron microscopy showed foamy intracytoplasmic vacuoles with a weakly electron-dense substrate. MPS VII is a very rare disease but it is possible that some cases go undiagnosed for several reasons, including that MPS VII, and other lysosomal storage diseases, are not included in the work-up for NIHF in many institutions, and the presence of anasarca at birth may be confounding for the recognition of the typical facial characteristics of the disease. This is the eighth patient affected by MPS VII who has undergone HCT. It is not

While many institutional activities of Church bodies fall within the scope of the recent reform of Italian law on non-profit organizations ("NPOs"), the specific features of Church bodies prevent from a straightforward application of the new regime. Therefore, the Code for the Third Sector and the Act on Social Enterprises allow Church bodies to access the tax exemptions and the other benefits provided to NPOs as far as they comply with a set of conditions aimed at bridging the differences between Church bodies and secular NPOs. The paper (1) discusses in details these conditions, (2) offers a critical evaluation of costs, risks, and opportunities related to the new regime, and (3) suggests possible organizational structures to comply with the current system.

Owing to their exposure on the cell surface and the possibility of being directly recognized with specific antibodies, glycosphingolipids have aroused great interest in the field of stem cell biology. In the search for specific markers of the differentiation of human bone marrow mesenchymal stem cells (hBMSCs ) toward osteoblasts, we studied their glycosphingolipid pattern, with particular attention to gangliosides. After lipid extraction and fractionation, gangliosides, metabolically 3H-labeled in the sphingosine moiety, were separated by high-performance TLC and chemically characterized by MALDI MS. Upon induction of osteogenic differentiation, a 3-fold increase of ganglioside GD1a was observed. Therefore, the hypothesis of GD1a involvement in hBMSCs commitment toward the osteogenic phenotype was tested by comparison of the osteogenic propensity of GD1a-highly expressing versus GD1a-low expressing hBMSCs and direct addition of GD1a in the differentiation medium. It was found that either the high expression of GD1a in hBMSCs or the addition of GD1a in the differentiation medium favored osteogenesis, providing a remarkable increase of alkaline phosphatase. It was also observed that ganglioside GD2, although detectable in hBMSCs by immunohistochemistry with an anti-GD2 antibody, could not be recognized by chemical analysis, likely reflecting a case, not uncommon, of molecular mimicry

The synthetic purine reversine has been shown to possess a dual activity as it promotes the de-differentiation of adult cells, including fibroblasts, into stem-cell-like progenitors, but it also induces cell growth arrest and ultimately cell death of cancer cells, suggesting its possible application as an anti-cancer agent. Aim of this study was to investigate the mechanism underneath reversine selectivity in inducing cell death of cancer cells by a comparative analysis of its effects on several tumor cells and normal dermal fibroblasts. We found that reversine is lethal for all cancer cells studied as it induces cell endoreplication, a process that malignant cells cannot effectively oppose due to aberrations in cell cycle checkpoints. On the other hand, normal cells, like dermal fibroblasts, can control reversine activity by blocking the cell cycle, entering a reversible quiescent state. However, they can be induced to become sensitive to the molecule when key cell cycle proteins, e.g., p53, are silenced.

ARKIVOC: vol. 2011, no. 6, (issn) 1551-7012, (dlps) 5550190.0012.618, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

ARKIVOC: vol. 2011, no. 6, (issn) 1551-7012, (dlps) 5550190.0012.618, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

Tiziana Ramaci,1 Monica Pellerone,1 Caterina Ledda,2 Giovambattista Presti,1 Valeria Squatrito,1 Venerando Rapisarda2 1Faculty of Human and Social Sciences, “Kore” University of Enna, Enna, 2Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy Background: Gender beliefs represent cultural schemas for interpreting or making sense of the social and employment world, as they can influence attitudes, career aspirations, and the vocational decision process of young people, especially the adolescence.Materials and methods: This study examined the influence of gender stereotypes on the choice of career in adolescents. A group of 120 students were recruited to complete an ad hoc questionnaire, Scale of Perceived Occupational Self-Efficacy, and Semantic Differentials. The objectives of the study were to analyze the relationship between occupational self-efficacy and professional preference; to measure the influence of independent variables, such as age and gender, on the representation that students have of themselves and of the profession; and to identify the predictor variables of self-efficacy in the vocational decision.Results: Data showed that the distance between professional identity and social identity increases with age. Results underline that males seem to perceive themselves more self-efficient in military, scientific–technological, and agrarian professions than females. Furthermore, the type of job performed by parents appears to be a self-efficacy predictor variable in the choice of professions in the services area.Conclusion: Individuals’ perceived occupational self-efficacy, gender, age, and parents’ profession have implications for exploratory behavior. The conditions that make gender differences salient are more likely to favor self-representations of the career and consistent assessments with these representations. Keywords: adolescent, gender stereot

Ramaci T, Pellerone M, Ledda C, Presti G, Squatrito V, Rapisarda V. Psychol Res Behav Manag. 2017;10:109–117. On page 116, Reference section, an error was introduced in the numbering regarding reference 44. The correct reference details are:44. Wraga M, Duncan L, Jacobs EC, Helt M, Church J. Stereotype susceptibility narrows the gender gap in imagined self-rotation performance. Psychon Bull Rev. 2006;13(5):813–819.The reference citation in the main text is correct.Read the original article

Tiziana Ramaci,1 Monica Pellerone,1 Caterina Ledda,2 Venerando Rapisarda2 1Faculty of Human and Social Sciences, Kore University of Enna, Enna, Italy; 2Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy Background: Job insecurity resulting from new types of employment contracts, together with organizational dynamics such as restructuring and internationalization, is emerging as an important source of organizational and individual stress, often transforming the workplace into a hostile and, above all, extremely demanding context from a psychological point of view.Materials and methods: The aim of this study was to identify the possible relationships between individual and organizational dimensions of work (such as engagement, autonomy, personal and collective efficacy at work, and satisfaction) and their impact on stress levels. The survey involved 120 Italian workers: 72 females (60%) and 48 males (40%), with a mean age of 41.8 years ±7.31 years. The groups of participants were selected on the basis of employment contract type (traditional or atypical) to emphasize potential differences. The study was conducted using a set of self-administered questionnaires, including the Psychological Stress Measure and Utrecht Work Engagement Scale.Results: The data show that personal and collective efficacy at work correlates negatively with stress, which in turn correlates negatively with engagement and satisfaction. The results support the hypothesis that job insecurity could be considered a strong predictor of poor health.Conclusion: The study should be considered as a preliminary assessment prior to studies of broader interventions to increase quality of life. Keywords: well-being, workers, stress, efficacy, satisfaction, autonomy, organizational process

Recent advances in stem cell biology have demonstrated that terminally differentiated adult cells can be induced to de-differentiate into progenitor cells (induced stem cells) upon proper stimuli. This has been achieved by the induced expression of key regulatory genes by retro- or lenti-viral systems. On the other hand, synthetic "small molecules" can also induce de-differentiation and may represent a potentially safer approach as compared with genetic manipulation. Along this line, a synthetic purine called "reversine" has been shown to induce the de-differentiation of fibroblasts into mesenchymal stem-cell-like progenitors, which can be successively induced to differentiate into skeletal muscle, smooth muscle and bone cells. The mechanism whereby reversine is able to achieve de-differentiation has yet to be clarified. In this context, we defined the protein changes induced by reversine treatment in murine fibroblasts by 2-D difference gel electrophoresis, coupled with MS. Proteins involved in cytoskeletal and cell shape remodeling, RNA export, degradation, folding, stress control and ATP production were found to be remarkably changed after reversine treatment. Ingenuity pathway analysis (IPA) predicted that these protein pattern changes enabled to propose that about 40 proteins might be associated to several biological functional networks, including cellular assembly, cell signaling and cell death. Altogether our data confirm the intrinsic complexity of the de-differentiation process induced by reversine and suggest more selected approaches to investigate the action mechanism of this small molecule

Human sialidase NEU4 long (N4L) is a membrane-associated enzyme that has been shown to be localized in the outer mitochondrial membrane. A role in different cellular processes has been suggested for this enzyme, such as apop-tosis, neuronal differentiation and tumorigenesis. However, the molecular bases for these roles, not found in any of the other highly similar human sialidases, are not understood. We have found that a proline-rich sequence of 81 amino acids, unique to NEU4 sequence, contains potential Akt and Erk1 kinase motifs. Molecular modeling, based on the experimentally determined three-dimensional structure of cytosolic human NEU2, showed that the proline-rich sequence is accommodated in a loop, thus preserving the typical beta-barrel structure of sialidases. In order to investigate the role of this loop in neuronal differentiation, we obtained SK-N-BE neuroblastoma cells stably overexpres-sing either human wild-type N4L or a deletion mutant lacking the proline-rich loop. Our results demonstrate that the proline-rich region can also enhance cell proliferation and retinoic acid (RA)-induced neuronal differentiation and it is also involved in NEU4 interaction with Akt, as well as in substrate recognition, modifying directly or through the interaction with other protein(s) the enzyme specificity toward sialylated glycoprotein(s). On the whole, our results suggest that N4L could be a downstream component of the PI3K/Akt signaling pathway required for RA-induced differentiation of neuroblastoma SK-N-BE cells. © The Author 2013.

Background. Infectious diseases seem to be an important and independent risk factor for renal failure, but the underlying mechanism of renal involvement during some kinds of infectious diseases is still unclear, even if the literature data report immunomediated and/or autoimmune mechanisms to explain the pathogenic relationship between the two diseases. In paediatric patients, Chlamydia pneumoniae is a rare cause of renal complications and it may manifest in several ways, mainly involving the respiratory system, even if also renal and glomerulalr complications, have been described. Case Diagnosis/Treatment. Herein we report a case of a 3-year-old child who developed an acute glomerulonephritis that was chronologically, clinically, and biologically related to a previous Chlamydia pneumoniae infection. On our knowledge, in the literature it is the youngest patient with renal involvement during course of Chlamydia pneumoniae infection ever reported. Conclusions. The present case supports the hypothesis of a rather close causal relationship between this infective agent and renal and glomerular symptoms occurred in this child, during an acute episode of respiratory disease.

Diastereoselective asymmetric 1,3-dipolar cycloadditions of N-(alkoxycarbonylmethyl) nitrones derived from glycine, alanine and phenylalanine have been studied both experimentally and theoretically. Asymmetric induction is evaluated by either introducing a chiral group at the nitrone nitrogen atom or by using Oppolzer's sultam acrylamide. In both cases the sense of the asymmetric induction is the same, the (3R,5R)-isomer being preferentially obtained. The best results were observed with the chiral dipolarophile, which afforded an only isomer in all cases. The obtained isoxazolidines are easily transformed into the corresponding 5-substituted-3-hydroxypyrrolidin-2-ones. DFT studies are in a qualitative agreement with the observed experimental results. © 2013 Elsevier Ltd. All rights reserved.

Two monomers for the syntheses of conformationally restricted peptide nucleic acids were synthesized through a simple procedure, involving an asymmetric 1,3-dipolar cycloaddition chemistry as a key step, from common starting materials in 3 and 5 steps, and 58.8% and 30.5% overall yields, respectively.

Context: Sclerostin, a Wnt signaling antagonist on the osteoblasts produced by osteocytes, is regulated by mechanical strain and is implicated in the pathogenesis of disuse bone loss. There are no data on sclerostin in humans. Objective: The aim of the study was to evaluate sclerostin in patients immobilized after stroke, compared with control subjects, and to analyze its relationship with markers of bone formation and resorption. Design: This was a cross-sectional study. Setting and patients: We studied 40 postmenopausal women immobilized after a single episode of stroke 6 months or longer after onset, and 40 postmenopausal women from the general community. Bone status was assessed by quantitative ultrasound measurements at the calcaneus. Bone alkaline phosphatase (b-AP), carboxy-terminal telopeptide of type I collagen (CrossLaps), and sclerostin were evaluated by ELISA. We also used ELISA to measure serum levels of Dickkopf-1, another soluble inhibitor of Wnt/beta-catenin signaling, highly expressed by osteocytes. Results: Immobilized patients had higher sclerostin serum levels (median 0.975 ng/ml; 25th to 75th percentiles 0.662-1.490) than controls (median 0.300 ng/ml; 25th to 75th percentiles 0.165-0.400: P < 0.0001) and an increased bone turnover with a more significant rise in bone resorption (CrossLaps) than formation (b-AP) markers. Sclerostin correlated negatively with b-AP (r = -0.911; P < 0.0001) and positively with CrossLaps (r = 0.391; P = 0.012). Dickkopf-1 did not significantly differ between the groups. Patients also had quantitative ultrasound measurements index lower than controls (P < 0.001). Conclusions: This study shows for the first time that long-term immobilized patients present hypersclerostinemia associated with reduced bone formation, and suggests that sclerostin could be a link between mechanical unloading and disuse osteoporosis in humans.

Sialidases are widely distributed glycohydrolytic enzymes removing sialic acid residues from glycoconjugates. In mammals, several sialidases with different subcellular localizations and biochemical features have been described. NEU4, the most recently identified member of the human sialidase family, is found in two forms, NEU4 long and NEU4 short, differing in the presence of a 12-amino-acid sequence at the N-terminus. Contradictory data are present in the literature about the subcellular distribution of these enzymes, their membrane anchoring mechanism being still unclear. In this work, we investigate the human NEU4 long and NEU4 short membrane anchoring mechanism and their subcellular localization. Protein extraction with Triton X-114 and sodium carbonate and cross-linking experiments demonstrate that both forms of NEU4 are extrinsic membrane proteins, anchored via protein-protein interactions. Moreover, through confocal microscopy and subcellular fractionation, we show that the long form localizes in mitochondria, while the short form is also associated with the endoplasmic reticulum. Finally, mitochondria subfractionation experiments suggest that NEU4 long is bound to the outer mitochondrial membrane.

With the global spread of the pandemic H1N1 and the ongoing pandemic potential of the H5N1 subtype, the influenza virus represents one of the most alarming viruses spreading worldwide. The influenza virus sialidase is an effective drug target, and a number of inhibitors are clinically effective against the virus (zanamivir, oseltamivir, peramivir). Here we report structural and biochemical studies of the human cytosolic sialidase Neu2 with influenza virus sialidase-targeting drugs and related compounds.

SUMMARY The transformation of (5R)-2,6-di-O-benzyl-5-C-methoxy-β-d-galactopyranosyl-(1→4)-2,3:5,6-di-O-isopropylidene-aldehydo-d-glucose dimethyl acetal (8) into partially protected derivatives of d-xylo- and l-lyxo-aldohexos-5-ulose has been reported, applying appropriate epimerisation methods to its 3′-O- and 4′-O-protected alcoholic derivatives.

ARKIVOC: vol. 2009, no. 8, (issn) 1551-7012, (dlps) 5550190.0010.810, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

ARKIVOC: vol. 2009, no. 8, (issn) 1551-7012, (dlps) 5550190.0010.810, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

ARKIVOC: vol. 2006, no. 6, (issn) 1551-7012, (dlps) 5550190.0007.608, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

ARKIVOC: vol. 2006, no. 6, (issn) 1551-7012, (dlps) 5550190.0007.608, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

Gangliosides play key roles in cell differentiation, cell-cell interactions, and transmembrane signaling. Sialidases hydrolyze sialic acids to produce asialo compounds, which is the first step of degradation processes of glycoproteins and gangliosides. Sialidase involvement has been implicated in some lysosomal storage disorders such as sialidosis and galactosialidosis. Neu2 is a recently identified human cytosolic sialidase. Here we report the first high resolution x-ray structures of mammalian sialidase, human Neu2, in its apo form and in complex with an inhibitor, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid ( DANA). The structure shows the canonical six-blade beta-propeller observed in viral and bacterial sialidases with its active site in a shallow crevice. In the complex structure, the inhibitor lies in the catalytic crevice surrounded by ten amino acids. In particular, the arginine triad, conserved among sialidases, aids in the proper positioning of the carboxylate group of DANA within the active site region. The tyrosine residue, Tyr(334), conserved among mammalian and bacterial sialidases as well as in viral neuraminidases, facilitates the enzymatic reaction by stabilizing a putative carbonium ion in the transition state. The loops containing Glu(111) and the catalytic aspartate Asp(46) are disordered in the apo form but upon binding of DANA become ordered to adopt two short alpha-helices to cover the inhibitor, illustrating the dynamic nature of substrate recognition. The N-acetyl and glycerol moieties of DANA are recognized by Neu2 residues not shared by bacterial sialidases and viral neuraminidases, which can be regarded as a key structural difference for potential drug design against bacteria, influenza, and other viruses.

Recombinant human cytosolic sialidase (HsNEU2), expressed in Escherichia coli, was purified to homogeneity, and its substrate specificity was studied. HsNEU2 hydrolyzed 4-methylumbelliferyl alpha-NeuAc, alpha2-->3 sialyl-lactose, glycoproteins (fetuin, alpha-acid glycoprotein, transferrin, and bovine submaxillary gland mucin), micellar gangliosides GD1a, GD1b, GT1b, and alpha2-->3 paragloboside, and vesicular GM3. alpha2-->6 sialyllactose, colominic acid, GM1 oligosaccharide, whereas micellar GM2 and GM1 were resistant. The optimal pH was 5.6, kinetics Michaelis-Menten type, V-max varying from 250 IU/mg protein (GD1a) to 0.7 IU/mg protein (alpha(1)-acid glycoprotein), and K-m in the millimolar range. HsNEU2 was activated by detergents (Triton X-100) only with gangliosidic substrates; the change of GM3 from vesicular to mixed micellar aggregation led to a 8.5-fold V-max increase. HsNEU2 acted on gangliosides (GD1a, GM1, and GM2) at nanomolar concentrations. With these dispersions (studied in detailed on GM1), where monomers are bound to the tube wall or dilutedly associated (1:2000, mol/mol) to Triton X-100 micelles, the V-max values were 25 and 72 muIU/mg protein, and K-m was 10 and 15x10(-9) M, respectively. Remarkably, GM1 and GM2 were recognized only as monomers. HsNEU2 worked at pH 7.0 with an efficiency (compared with that at pH 5.6) ranging from 4% (on GD1a) to 64% (on alpha(1)-acid glycoprotein), from 7% (on GD1a) to 45% (on GM3) in the presence of Triton X-100, and from 30 to 40% on GM1 monomeric dispersion. These results show that HsNEU2 differentially recognizes the type of sialosyl linkage, the aglycone part of the substrate, and the supramolecular organization (monomer/micelle/vesicle) of gangliosides. The last ability might be relevant in sialidase interactions with gangliosides under physiological conditions.

ARKIVOC: vol. 2002, no. 11, (issn) 1551-7012, (dlps) 5550190.0003.b15, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

ARKIVOC: vol. 2002, no. 11, (issn) 1551-7012, (dlps) 5550190.0003.b15, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

ARKIVOC: vol. 2002, no. 8, (issn) 1551-7012, (dlps) 5550190.0003.802, This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 License. Please contact mpub-help@umich.edu to use this work in a way not covered by the license.

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The thermotropic behavior (studied by high-sensitivity differential scanning calorimetry) and susceptibility to Vibrio cholerae sialidase hydrolysis of large unilamellar vesicles of dipalmitoyl-phosphatidylcholine, containing native GD1a ganglioside or the molecular species of GD1a containing C18:1 or C20:1 long-chain base (C18:1 GD1a; C20:1 GD1a), were studied. Vesicles containing ganglioside (10% in molar terms) showed the presence in the heat capacity function of a second minor peak besides the phospholipid main transition peak. The presence of a second peak is much more evident with C20:1 GD1a than with C18:1 GD1a, the difference being potentiated by Ca2+ and indicating a different tendency of the CD1a molecular species to undergo lateral phase separation. The scans of vesicles containing native GD1a showed the features of those obtained with C18:1 GD1a and C20:1 GD1a, indicating that the main components of native GD1a, C18:1 GD1a and C20:1 GD1a, maintain their individual aggregative properties. V. cholerae sialidase affects vesicle-bound GD1a at a much higher rate (17-25-fold) than it does micellar GD1a, the activation by Ca2+ being 3- and 2-fold, respectively. The Vmax values were identical on C18:1 GD1a and C20:1 GD1a in micellar dispersions, whereas they were markedly higher (from 20 to 50%) on C18:1 GD1a than on C20:1 GD1a in vesicular dispersions. Exhaustive sialidase hydrolysis of vesicles carrying native GD1a produced C18:1 GM1 and C20:1 GM1 in the same proportion as the C18:1 and C20:1 species present in native GD1a (53.9% and 46.1%).(ABSTRACT TRUNCATED AT 250 WORDS)

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NON DISPONIBILE