Amyotrophic lateral sclerosis is a progressive neurodegenerative disease of motor neurons. About 25 genes have been verified as relevant to the disease process, with rare and common variation ...implicated. We used next generation sequencing and repeat sizing to comprehensively assay genetic variation in a panel of known amyotrophic lateral sclerosis genes in 1126 patient samples and 613 controls. About 10% of patients were predicted to carry a pathological expansion of the C9orf72 gene. We found an increased burden of rare variants in patients within the untranslated regions of known disease-causing genes, driven by SOD1, TARDBP, FUS, VCP, OPTN and UBQLN2. We found 11 patients (1%) carried more than one pathogenic variant (P = 0.001) consistent with an oligogenic basis of amyotrophic lateral sclerosis. These findings show that the genetic architecture of amyotrophic lateral sclerosis is complex and that variation in the regulatory regions of associated genes may be important in disease pathogenesis.
There is increasing evidence that endogenous retroviruses (ERVs) play a significant role in central nervous system diseases, including amyotrophic lateral sclerosis (ALS). Studies of ALS have ...consistently identified retroviral enzyme reverse transcriptase activity in patients. Evidence indicates that ERVs are the cause of reverse transcriptase activity in ALS, but it is currently unclear whether this is due to a specific ERV locus or a family of ERVs. We employed a combination of bioinformatic methods to identify whether specific ERVs or ERV families are associated with ALS. Using the largest post-mortem RNA-sequence datasets available we selectively identified ERVs that closely resembled full-length proviruses. In the discovery dataset there was one ERV locus (HML6_3p21.31c) that showed significant increased expression in post-mortem motor cortex tissue after multiple-testing correction. Using six replication post-mortem datasets we found HML6_3p21.31c was consistently upregulated in ALS in motor cortex and cerebellum tissue. In addition, HML6_3p21.31c showed significant co-expression with cytokine binding and genes involved in EBV, HTLV-1 and HIV type-1 infections. There were no significant differences in ERV family expression between ALS and controls. Our results support the hypothesis that specific ERV loci are involved in ALS pathology.
Nitric oxide (NO) has long been recognized to affect muscle contraction, both through activation of guanylyl cyclase and through modification of cysteines in proteins to yield S-nitrosothiols. While ...NO affects the contractile apparatus directly, the identities of the target myofibrillar proteins remain unknown. Here we report that nitrogen oxides directly regulate striated muscle myosins.
Exposure of skeletal and cardiac myosins to physiological concentrations of nitrogen oxides, including the endogenous nitrosothiol S-nitroso-L-cysteine, reduced the velocity of actin filaments over myosin in a dose-dependent and oxygen-dependent manner, caused a doubling of force as measured in a laser trap transducer, and caused S-nitrosylation of cysteines in the myosin heavy chain. These biomechanical effects were not observed in response to S-nitroso-D-cysteine, demonstrating specificity for the naturally occurring isomer. Both myosin heavy chain isoforms in rats and cardiac myosin heavy chain from human were S-nitrosylated in vivo.
These data show that nitrosylation signaling acts as a molecular "gear shift" for myosin--an altogether novel mechanism by which striated muscle and cellular biomechanics may be regulated.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Curcumin, a constituent of the spice turmeric, has been shown to reduce the adenoma burden in rodent models of colorectal
cancer accompanied by a reduction of levels of the oxidative DNA adduct ...3-(2-deoxy- β -di-erythro-pentafuranosyl)-pyr1,2-α-purin-10(3 H )one (M 1 G) and of expression of the enzyme cyclooxygenase-2 (COX-2). We tested the hypothesis that pharmacologically active levels
of curcumin can be achieved in the colorectum of humans as measured by effects on levels of M 1 G and COX-2 protein. Patients with colorectal cancer ingested curcumin capsules (3,600, 1,800, or 450 mg daily) for 7 days.
Biopsy samples of normal and malignant colorectal tissue, respectively, were obtained at diagnosis and at 6 to 7 hours after
the last dose of curcumin. Blood was taken 1 hour after the last dose of curcumin. Curcumin and its metabolites were detected
and quantitated by high-performance liquid chromatography with detection by UV spectrophotometry or mass spectrometry. M 1 G levels and COX-2 protein expression were measured by immunoslot blot and Western blotting, respectively. The concentrations
of curcumin in normal and malignant colorectal tissue of patients receiving 3,600 mg of curcumin were 12.7 ± 5.7 and 7.7 ± 1.8 nmol/g, respectively. Curcumin sulfate and curcumin glucuronide were identified in the tissue of these patients. Trace
levels of curcumin were found in the peripheral circulation. M 1 G levels were 2.5-fold higher in malignant tissue as compared with normal tissue ( P < 0.05 by ANOVA). Administration of curcumin (3,600 mg) decreased M 1 G levels from 4.8 ± 2.9 adducts per 107 nucleotides in malignant colorectal tissue to 2.0 ± 1.8 adducts per 107 nucleotides ( P < 0.05 by ANOVA). COX-2 protein levels in malignant colorectal tissue were not affected by curcumin. The results suggest
that a daily dose of 3.6 g curcumin achieves pharmacologically efficacious levels in the colorectum with negligible distribution
of curcumin outside the gut.
Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disorder. Since no diagnostic laboratory test exists, the identification of specific biomarkers could be fundamental in ...clinical practice. microRNAs (miRNAs) are considered promising biomarkers for neurodegenerative diseases. The aim of the study was to identify a CSF miRNA set that could differentiate ALS from non-ALS condition. miRNA profiling in CSF from ALS patients (
n
= 24; eight with
C9orf72
expansion) and unaffected control subjects (
n
= 24) by quantitative reverse transcription PCR identified fourteen deregulated miRNAs. Validation experiments confirmed eight miRNAs as significantly deregulated in ALS. No significant differences were observed between ALS patients with or without
C9orf72
expansion. The receiver operator characteristic (ROC) curve analyses revealed the highest diagnostic accuracy for the upregulated miR181a-5p and the downregulated miR21-5p and miR15b-5p. The miR181a-5p/miR21-5p and miR181a-5p/miR15b-5p ratios detected ALS with 90 and 85 % sensitivity and 87 and 91 % specificity, respectively, confirming the application potential as disease biomarkers. These deregulated miRNAs are implicated in apoptotic way and provide insight into processes responsible for motor neuron degeneration.
TIGIT is an inhibitory receptor expressed on lymphocytes and can inhibit T cells by preventing CD226 co-stimulation through interactions in cis or through competition of shared ligands. Whether TIGIT ...directly delivers cell-intrinsic inhibitory signals in T cells remains unclear. Here we show, by analysing lymphocytes from matched human tumour and peripheral blood samples, that TIGIT and CD226 co-expression is rare on tumour-infiltrating lymphocytes. Using super-resolution microscopy and other techniques, we demonstrate that ligation with CD155 causes TIGIT to reorganise into dense nanoclusters, which coalesce with T cell receptor (TCR)-rich clusters at immune synapses. Functionally, this reduces cytokine secretion in a manner dependent on TIGIT's intracellular ITT-like signalling motif. Thus, we provide evidence that TIGIT directly inhibits lymphocyte activation, acting independently of CD226, requiring intracellular signalling that is proximal to the TCR. Within the subset of tumours where TIGIT-expressing cells do not commonly co-express CD226, this will likely be the dominant mechanism of action.
The expansion of a hexanucleotide repeat GGGGCC in C9orf72 is the most common known cause of ALS accounting for ~ 40% familial cases and ~ 7% sporadic cases in the European population. In most ...people, the repeat length is 2, but in people with ALS, hundreds to thousands of repeats may be observed. A small proportion of people have an intermediate expansion, of the order of 20 to 30 repeats in size, and it remains unknown whether intermediate expansions confer risk of ALS in the same way that massive expansions do. We investigated the association of this intermediate repeat with ALS by performing a meta-analysis of four previously published studies and a new British/Alzheimer's Disease Neuroimaging Initiative dataset of 1295 cases and 613 controls. The final dataset comprised 5071 cases and 3747 controls. Our meta-analysis showed association between ALS and intermediate C9orf72 repeats of 24 to 30 repeats in size (random-effects model OR = 4.2, 95% CI = 1.23-14.35, p-value = 0.02). Furthermore, we showed a different frequency of the repeat between the northern and southern European populations (Fisher's exact test p-value = 5 × 10
). Our findings provide evidence for the association between intermediate repeats and ALS (p-value = 2 × 10
) with direct relevance for research and clinical practice by showing that an expansion of 24 or more repeats should be considered pathogenic.
Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease for which the genetic contribution is incompletely understood.
We conducted a joint analysis of 5,523,934 imputed SNPs in two ...newly-genotyped progressive supranuclear palsy cohorts, primarily derived from two clinical trials (Allon davunetide and NNIPPS riluzole trials in PSP) and a previously published genome-wide association study (GWAS), in total comprising 1646 cases and 10,662 controls of European ancestry.
We identified 5 associated loci at a genome-wide significance threshold P < 5 × 10
, including replication of 3 loci from previous studies and 2 novel loci at 6p21.1 and 12p12.1 (near RUNX2 and SLCO1A2, respectively). At the 17q21.31 locus, stepwise regression analysis confirmed the presence of multiple independent loci (localized near MAPT and KANSL1). An additional 4 loci were highly suggestive of association (P < 1 × 10
). We analyzed the genetic correlation with multiple neurodegenerative diseases, and found that PSP had shared polygenic heritability with Parkinson's disease and amyotrophic lateral sclerosis.
In total, we identified 6 additional significant or suggestive SNP associations with PSP, and discovered genetic overlap with other neurodegenerative diseases. These findings clarify the pathogenesis and genetic architecture of PSP.
The ALS Online Genetics Database (ALSoD) website holds mutation, geographical, and phenotype data on genes implicated in amyotrophic lateral sclerosis (ALS) and links to bioinformatics resources, ...publications, and tools for analysis. On average, there are 300 unique visits per day, suggesting a high demand from the research community. To enable wider access, we developed a mobile-friendly version of the website and a smartphone app.
We sought to compare data traffic before and after implementation of a mobile version of the website to assess utility.
We identified the most frequently viewed pages using Google Analytics and our in-house analytic monitoring. For these, we optimized the content layout of the screen, reduced image sizes, and summarized available information. We used the Microsoft .NET framework mobile detection property (HttpRequest.IsMobileDevice in the Request.Browser object in conjunction with HttpRequest.UserAgent), which returns a true value if the browser is a recognized mobile device. For app development, we used the Eclipse integrated development environment with Android plug-ins. We wrapped the mobile website version with the WebView object in Android. Simulators were downloaded to test and debug the applications.
The website automatically detects access from a mobile phone and redirects pages to fit the smaller screen. Because the amount of data stored on ALSoD is very large, the available information for display using smartphone access is deliberately restricted to improve usability. Visits to the website increased from 2231 to 2820, yielding a 26% increase from the pre-mobile to post-mobile period and an increase from 103 to 340 visits (230%) using mobile devices (including tablets). The smartphone app is currently available on BlackBerry and Android devices and will be available shortly on iOS as well.
Further development of the ALSoD website has allowed access through smartphones and tablets, either through the website or directly through a mobile app, making genetic data stored on the database readily accessible to researchers and patients across multiple devices.
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