849 research outputs found
RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord
ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients
Expected performance of the ASTRI-SST-2M telescope prototype
ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an
Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica)
strictly linked to the development of the Cherenkov Telescope Array, CTA.
Primary goal of the ASTRI program is the design and production of an end-to-end
prototype of a Small Size Telescope for the CTA sub-array devoted to the
highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be
tested on field in Italy during 2014. This telescope will be the first
Cherenkov telescope adopting the double reflection layout in a
Schwarzschild-Couder configuration with a tessellated primary mirror and a
monolithic secondary mirror. The collected light will be focused on a compact
and light-weight camera based on silicon photo-multipliers covering a 9.6 deg
full field of view. Detailed Monte Carlo simulations have been performed to
estimate the performance of the planned telescope. The results regarding its
energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
Antiproton slowing Down in H2 and He and evidence of nuclear stopping power
We report stopping powers of hydrogen and helium for antiprotons of kinetic energies ranging from about 0.5 keV to 1.1 MeV. The Barkas effect, i.e., a difference in the stopping power for antiprotons and protons of the same energy in the same material, shows up clearly in either of the gases. Moreover, below ≈0.5 keV there is indirect evidence for an increase of the antiproton stopping power. This "nuclear" effect, i.e., energy losses in quasimolecular interactions, shows up in fair agreement with theoretical predictions
Further insights into Allan-Herndon-Dudley syndrome: a novel SLC16A2 splice site variant
Background
Genetics variants in SLC16A2 gene encoding for the monocarboxylate transporter 8 (MCT8) cause a severe X-linked leukoencephalopathy known as Allan-Herndon-Dudley syndrome (AHDS). MCT8 promotes cellular uptake and efflux of thyroid hormone. Iodothyronine deiodinases (DIO) 1 and 2 are implicated in the conversion of T4 into biologically active T3, while DIO3 converts T4 into the inactive hormone reverse T3 (rT3). Active T3 and retinoid X receptors (RXR) can form heterodimer complexes which bind to hormone response elements (HREs) that leads to activate or repress transcription.
Aim of the study
The aim of this work is to investigate the impact of a novel SLC16A2 splice site variant on the pathogenesis of AHDS.
Materials and Methods
In silico prediction tools, such as Mutation Taster, were used to assess the pathogenic score of the identified variant, while splicing prediction tools, such as Fruit Fly Splice Predictor, were used to analyze the effect of variant on the splicing mechanism. Fibroblasts were obtained from skin biopsies of both AHDS patient and a matched control. To evaluate MCT8 and thyroid hormone signaling pathway related genes expression, RNA was extracted with TRIzoLTM and assessed by Real-Time PCR. Protein expression was evaluated via western blot and immunofluorescence. MTT assay was used to compare cell viability. Live and dead assay was used to discriminate live and dead populations. Lipid droplets were detected via oil red o staining.
Results
The identified variant in the SLC16A2 gene causes the breakup of the wild type donor splice site, possibly leading to exon 1 skipping, affecting cell viability.
SLC16A2 RNA expression in our AHDS patient was extremely reduced in comparison with total RNA from healthy control. DIO2, progastricsin, HR and KLF9 RNA expression resulted upregulated, whilst DIO1, DIO2-AS1, DIO3 and TH were downregulated influencing T3 cell entrance. Myelin related genes were significatively reduced. The lipid staining revealed an increasing presence of lipid droplets in AHDS patients.
Conclusions
Our preliminary data emphasize an impairment in AHDS fibroblasts in relation to SLC16A2 splice site variant, increasing our understanding in the pathogenic mechanism of patients affected by AHDS
Clinical pregenetic screening for stroke monogenic diseases: Results from lombardia GENS registry
BACKGROUND AND PURPOSE:
Lombardia GENS is a multicentre prospective study aimed at diagnosing 5 single-gene disorders associated with stroke (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, Fabry disease, MELAS [mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes], hereditary cerebral amyloid angiopathy, and Marfan syndrome) by applying diagnostic algorithms specific for each clinically suspected disease
METHODS:
We enrolled a consecutive series of patients with ischemic or hemorrhagic stroke or transient ischemic attack admitted in stroke units in the Lombardia region participating in the project. Patients were defined as probable when presenting with stroke or transient ischemic attack of unknown etiopathogenic causes, or in the presence of <3 conventional vascular risk factors or young age at onset, or positive familial history or of specific clinical features. Patients fulfilling diagnostic algorithms specific for each monogenic disease (suspected) were referred for genetic analysis.
RESULTS:
In 209 patients (57.4\ub114.7 years), the application of the disease-specific algorithm identified 227 patients with possible monogenic disease. Genetic testing identified pathogenic mutations in 7% of these cases. Familial history of stroke was the only significant specific feature that distinguished mutated patients from nonmutated ones. The presence of cerebrovascular risk factors did not exclude a genetic disease.
CONCLUSIONS:
In patients prescreened using a clinical algorithm for monogenic disorders, we identified monogenic causes of events in 7% of patients in comparison to the 1% to 5% prevalence reported in previous series
Inhibition of the de-myelinating properties of Aicardi-Goutières syndrome lymphocytes by cathepsin D silencing.
Molecular mechanisms relating interferon-alpha (IFN-alpha) to brain damage have recently been identified in a microarray analysis of cerebrospinal fluid lymphocytes from patients with Aicardi-Goutières Syndrome (AGS). These findings demonstrate that the inhibition of angiogenesis and the activation of neurotoxic lymphocytes are the major pathogenic mechanisms involved in the brain damage consequent to elevated interferon-alpha levels. Our previous study demonstrated that cathepsin D, a lysosomal aspartyl endopeptidase, is the primary mediator of the neurotoxicity exerted by AGS lymphocytes. Cathepsin D is a potent pro-apoptotic, neurotoxic, and demyelinating protease if it is not properly inhibited by the activities of leukocystatins. In central nervous system white matter, demyelination results from cathepsin over-expression when not balanced by the expression of its inhibitors. In the present study, we used RNA interference to inhibit cathepsin D expression in AGS lymphocytes with the aim of decreasing the neurotoxicity of these cells. Peripheral blood lymphocytes collected from an AGS patient were immortalized and co-cultured with astrocytes in the presence of interferon alpha with or without cathepsin D RNA interference probes. Cathepsin D expression was measured by qPCR, and neurotoxicity was evaluated by microscopy. RNA interference inhibited cathepsin D over-production by 2.6-fold (P<0.01) in AGS lymphocytes cultured in the presence of interferon alpha. AGS lymphocytes treated using RNA interference exhibited a decreased ability to induce neurotoxicity in astrocytes. Such neurotoxicity results in the inhibition of astrocyte growth and the inhibition of the ability of astrocytes to construct web-like aggregates. These results suggest a new strategy for repairing AGS lymphocytes in vitro by inhibiting their ability to induce astrocyte damage and leukodystroph
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