RESUMEN
Reduced provision of protein translation machinery promotes healthy aging in a number of animal models. In humans, however, inborn impairments in translation machinery are a known cause of several developmental disorders, collectively termed ribosomopathies. Here, we use casual inference approaches in genetic epidemiology to investigate whether adult, tissue-specific biogenesis of translation machinery drives human aging. We assess naturally occurring variation in the expression of genes encoding subunits specific to the two RNA polymerases (Pols) that transcribe ribosomal and transfer RNAs, namely Pol I and III, and the variation in expression of ribosomal protein (RP) genes, using Mendelian randomization. We find each causally associated with human longevity (ß = -0.15 ± 0.047, P = 9.6 × 10-4, q = 0.015; ß = -0.13 ± 0.040, P = 1.4 × 10-3, q = 0.023; ß = -0.048 ± 0.016, P = 3.5 × 10-3, q = 0.056, respectively), and this does not appear to be mediated by altered susceptibility to a single disease. We find that reduced expression of Pol III, RPs, or Pol I promotes longevity from different organs, namely visceral adipose, liver, and skeletal muscle, echoing the tissue specificity of ribosomopathies. Our study shows the utility of leveraging genetic variation in expression to elucidate how essential cellular processes impact human aging. The findings extend the evolutionary conservation of protein synthesis as a critical process that drives animal aging to include humans.
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Envejecimiento , Biosíntesis de Proteínas , ARN Polimerasa I , Envejecimiento/genética , Animales , ARN Polimerasas Dirigidas por ADN , Humanos , Análisis de la Aleatorización Mendeliana , ARN Polimerasa I/metabolismo , Proteínas Ribosómicas/genética , Ribosomas/genética , Ribosomas/metabolismoRESUMEN
T cell-based immunotherapy has revolutionized oncological treatment. However, many patients do not respond to treatment, and long-term remissions remain rare, particularly in gastrointestinal cancers like colorectal cancer (CRC). B7-H3 is overexpressed in multiple cancer entities including CRC on both tumor cells and tumor vasculature, the latter facilitating influx of effector cells into the tumor site upon therapeutic targeting. We generated a panel of T cell-recruiting B7-H3xCD3 bispecific antibodies (bsAbs) and show that targeting a membrane-proximal B7-H3 epitope allows for a 100-fold reduction of CD3 affinity. In vitro, our lead compound CC-3 showed superior tumor cell killing, T cell activation, proliferation, and memory formation, whereas undesired cytokine release was reduced. In vivo, CC-3 mediated potent antitumor activity in three independent models using immunocompromised mice adoptively transferred with human effector cells with regard to prevention of lung metastasis and flank tumor growth as well as elimination of large established tumors. Thus, fine-tuning of both target and CD3 affinities as well as binding epitopes allowed for the generation of a B7-H3xCD3 bsAbs with promising therapeutic activity. CC-3 is presently undergoing good manufacturing practice (GMP) production to enable evaluation in a clinical "first-in-human" study in CRC.
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Anticuerpos Biespecíficos , Neoplasias Gastrointestinales , Humanos , Ratones , Animales , Inmunoglobulina G , Linfocitos T , Neoplasias Gastrointestinales/terapia , Anticuerpos Biespecíficos/farmacología , Anticuerpos Biespecíficos/uso terapéutico , Inmunoterapia , Línea Celular TumoralRESUMEN
Dendritic cell (DC) aggresome-like induced structures (DALIS) are protein aggregates of polyubiquitylated proteins that form transiently during DC maturation. DALIS scatter randomly throughout the cytosol and serve as antigen storage sites synchronising DC maturation and antigen presentation. Maturation of DCs is accompanied by the induction of the ubiquitin-like modifier FAT10 (also known as UBD), which localises to aggresomes, structures that are similar to DALIS. FAT10 is conjugated to substrate proteins and serves as a signal for their rapid and irreversible degradation by the 26S proteasome similar to, yet independently of ubiquitin, thereby contributing to antigen presentation. Here, we have investigated whether FAT10 is involved in the formation and turnover of DALIS, and whether proteins accumulating in DALIS can be modified through conjunction to FAT10 (FAT10ylated). We found that FAT10 localises to DALIS in maturing DCs and that this localisation occurs independently of its conjugation to substrates. Additionally, we investigated the DALIS turnover in FAT10-deficient and -proficient DCs, and observed FAT10-mediated disassembly of DALIS. Thus, we report further evidence that FAT10 is involved in antigen processing, which may provide a functional rationale as to why FAT10 is selectively induced upon DC maturation.
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Presentación de Antígeno , Células Dendríticas , Diferenciación Celular , Cuerpos de Inclusión , Ubiquitina , Ubiquitinas/genéticaRESUMEN
BACKGROUND: People with liver disease are at increased risk of developing cardiovascular disease (CVD), however, there has yet been an investigation of incidence burden, risk, and premature mortality across a wide range of liver conditions and cardiovascular outcomes. METHODS: We employed population-wide electronic health records (EHRs; from 1998 to 2020) consisting of almost 4 million adults to assess regional variations in disease burden of five liver conditions, alcoholic liver disease (ALD), autoimmune liver disease, chronic hepatitis B infection (HBV), chronic hepatitis C infection (HCV) and NAFLD, in England. We analysed regional differences in incidence rates for 17 manifestations of CVD in people with or without liver disease. The associations between biomarkers and comorbidities and risk of CVD in patients with liver disease were estimated using Cox models. For each liver condition, we estimated excess years of life lost (YLL) attributable to CVD (i.e., difference in YLL between people with or without CVD). RESULTS: The age-standardised incidence rate for any liver disease was 114.5 per 100,000 person years. The highest incidence was observed in NAFLD (85.5), followed by ALD (24.7), HCV (6.0), HBV (4.1) and autoimmune liver disease (3.7). Regionally, the North West and North East regions consistently exhibited high incidence burden. Age-specific incidence rate analyses revealed that the peak incidence for liver disease of non-viral aetiology is reached in individuals aged 50-59 years. Patients with liver disease had a two-fold higher incidence burden of CVD (2634.6 per 100,000 persons) compared to individuals without liver disease (1339.7 per 100,000 persons). When comparing across liver diseases, atrial fibrillation was the most common initial CVD presentation while hypertrophic cardiomyopathy was the least common. We noted strong positive associations between body mass index and current smoking and risk of CVD. Patients who also had diabetes, hypertension, proteinuric kidney disease, chronic kidney disease, diverticular disease and gastro-oesophageal reflex disorders had a higher risk of CVD, as do patients with low albumin, raised C-reactive protein and raised International Normalized Ratio levels. All types of CVD were associated with shorter life expectancies. When evaluating excess YLLs by age of CVD onset and by liver disease type, differences in YLLs, when comparing across CVD types, were more pronounced at younger ages. CONCLUSIONS: We developed a public online app ( https://lailab.shinyapps.io/cvd_in_liver_disease/ ) to showcase results interactively. We provide a blueprint that revealed previously underappreciated clinical factors related to the risk of CVD, which differed in the magnitude of effects across liver diseases. We found significant geographical variations in the burden of liver disease and CVD, highlighting the need to devise local solutions. Targeted policies and regional initiatives addressing underserved communities might help improve equity of access to CVD screening and treatment.
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Enfermedades Cardiovasculares , Hepatitis C , Adulto , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/epidemiología , Carga Global de Enfermedades , Hepatitis C/complicaciones , Hepatitis C/epidemiología , Humanos , Persona de Mediana Edad , Años de Vida Ajustados por Calidad de Vida , Factores de RiesgoRESUMEN
Drosophila, like other invertebrates and plants, relies mainly on RNA interference for its defense against viruses. In flies, viral infection also triggers the expression of many genes. One of the genes induced, Vago, encodes a 18-kilodalton cysteine-rich polypeptide. Here we provide genetic evidence that the Vago gene product controlled viral load in the fat body after infection with drosophila C virus. Induction of Vago was dependent on the helicase Dicer-2. Dicer-2 belongs to the same DExD/H-box helicase family as do the RIG-I-like receptors, which sense viral infection and mediate interferon induction in mammals. We propose that this family represents an evolutionary conserved set of sensors that detect viral nucleic acids and direct antiviral responses.
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Proteínas de Drosophila/inmunología , Drosophila/inmunología , Drosophila/virología , ARN Helicasas/inmunología , Animales , Animales Modificados Genéticamente , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Electroforesis en Gel de Poliacrilamida , Cuerpo Adiposo/inmunología , Cuerpo Adiposo/virología , Regulación de la Expresión Génica/inmunología , Humanos , Filogenia , ARN Helicasas/genética , ARN Helicasas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribonucleasa III , Homología de Secuencia de Aminoácido , Transcripción Genética , Virosis/inmunologíaRESUMEN
OBJECTIVE: Impaired lysosomal degradation of α-synuclein and other cellular constituents may play an important role in Parkinson's disease (PD). Rare genetic variants in the glucocerebrosidase (GBA) gene were consistently associated with PD. Here we examine the association between rare variants in lysosomal candidate genes and PD. METHODS: We investigated the association between PD and rare genetic variants in 23 lysosomal candidate genes in 4096 patients with PD and an equal number of controls using pooled targeted next-generation DNA sequencing. Genewise association of rare variants in cases or controls was analyzed using the optimized sequence kernel association test with Bonferroni correction for the 23 tested genes. RESULTS: We confirm the association of rare variants in GBA with PD and report novel associations for rare variants in ATP13A2, LAMP1, TMEM175, and VPS13C. CONCLUSION: Rare variants in selected lysosomal genes, first and foremost GBA, are associated with PD. Rare variants in ATP13A2 and VPC13C previously linked to monogenic PD and more common variants in TMEM175 and VPS13C previously linked to sporadic PD in genome-wide association studies are associated with PD. © 2020 International Parkinson and Movement Disorder Society.
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Enfermedad de Parkinson , Estudio de Asociación del Genoma Completo , Glucosilceramidasa/genética , Humanos , Lisosomas , Mutación , Enfermedad de Parkinson/genéticaRESUMEN
Exploring an object's shape by touch also renders information about its surface roughness. It has been suggested that shape and roughness are processed distinctly in the brain, a result based on comparing brain activation when exploring objects that differed in one of these features. To investigate the neural mechanisms of top-down control on haptic perception of shape and roughness, we presented the same multidimensional objects but varied the relevance of each feature. Specifically, participants explored two objects that varied in shape (oblongness of cuboids) and surface roughness. They either had to compare the shape or the roughness in an alternative-forced-choice-task. Moreover, we examined whether the activation strength of the identified brain regions as measured by functional magnetic resonance imaging (fMRI) can predict the behavioral performance in the haptic discrimination task. We observed a widespread network of activation for shape and roughness perception comprising bilateral precentral and postcentral gyrus, cerebellum, and insula. Task-relevance of the object's shape increased activation in the right supramarginal gyrus (SMG/BA 40) and the right precentral gyrus (PreCG/BA 44) suggesting that activation in these areas does not merely reflect stimulus-driven processes, such as exploring shape, but also entails top-down controlled processes driven by task-relevance. Moreover, the strength of the SMG/PreCG activation predicted individual performance in the shape but not in the roughness discrimination task. No activation was found for the reversed contrast (roughness > shape). We conclude that macrogeometric properties, such as shape, can be modulated by top-down mechanisms whereas roughness, a microgeometric feature, seems to be processed automatically.
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Mapeo Encefálico/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Conducta Exploratoria/fisiología , Imagen por Resonancia Magnética/métodos , Percepción del Tacto/fisiología , Adulto , Aprendizaje Discriminativo/fisiología , Femenino , Humanos , Masculino , Distribución Aleatoria , Adulto JovenRESUMEN
We performed a genome-wide association study in 1,194 controls and 150 patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR, n = 96) or anti-leucine-rich glioma-inactivated1 (anti-LGI1, n = 54) autoimmune encephalitis. Anti-LGI1 encephalitis was highly associated with 27 single-nucleotide polymorphisms (SNPs) in the HLA-II region (leading SNP rs2858870 p = 1.22 × 10-17 , OR = 13.66 [7.50-24.87]). Potential associations, below genome-wide significance, were found with rs72961463 close to the doublecortin-like kinase 2 gene (DCLK2) and rs62110161 in a cluster of zinc-finger genes. HLA allele imputation identified association of anti-LGI1 encephalitis with HLA-II haplotypes encompassing DRB1*07:01, DQA1*02:01 and DQB1*02:02 (p < 2.2 × 10-16 ) and anti-NMDAR encephalitis with HLA-I allele B*07:02 (p = 0.039). No shared genetic risk factors between encephalitides were identified. Ann Neurol 2018;83:863-869.
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Autoanticuerpos/metabolismo , Encefalitis/genética , Predisposición Genética a la Enfermedad/genética , Enfermedad de Hashimoto/genética , Polimorfismo de Nucleótido Simple/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas/genética , Adolescente , Adulto , Anciano , Quinasas Similares a Doblecortina , Encefalitis/inmunología , Encefalitis/metabolismo , Femenino , Estudio de Asociación del Genoma Completo , Enfermedad de Hashimoto/inmunología , Enfermedad de Hashimoto/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular , Masculino , Persona de Mediana Edad , Proteínas/inmunología , Receptores de N-Metil-D-Aspartato/inmunología , Adulto JovenRESUMEN
The TNF and IFN-γ-inducible ubiquitin-like modifier HLA-F adjacent transcript 10 (FAT10) is most prominently expressed in immunological tissues but information regarding basal expression and inducibility of FAT10 in the different types of immune cells is still lacking. Hence, we investigated FAT10 mRNA expression in the major human and murine immune cell subsets, and FAT10 protein expression in human leukocytes. We isolated the different human leukocytes from peripheral blood and the murine immune cell subsets from spleen. The purified leukocytes were left untreated or stimulated with TNF and INF-γ or LPS to induce FAT10 followed by quantitative real-time PCR or western blot analysis. Basal expression of FAT10 mRNA and protein was generally low but strongly up-regulated by IFN-γ and TNF in all immune cell subsets. LPS treatment induced FAT10 expression marginally in human CD8+ T cells and murine granulocytes, but it increased Fat10 expression significantly in murine regulatory T cells. Yet, in human CD8+ T cells, natural killer cells, natural killer T cells, and dendritic cells, the FAT10 mRNA was expressed without induction. Similarly, murine macrophages, monocytes, and regulatory T cells expressed Fat10 in the absence of stimulation. In summary, our findings suggest particular functions of FAT10 in these cell types. Furthermore, we observed not only a cell type-specific but also a species-specific basal FAT10 expression profile. Our data will serve as a guideline for future investigations to further elucidate FAT10's role in the immune system.
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Leucocitos/metabolismo , Ubiquitinas/genética , Ubiquitinas/fisiología , Animales , Células HEK293 , Humanos , Interferón gamma/metabolismo , Leucocitos/inmunología , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Transcriptoma/genética , Factor de Necrosis Tumoral alfa/metabolismo , Ubiquitinas/metabolismo , Regulación hacia ArribaRESUMEN
Resting CD4+ T-cells harboring inducible HIV proviruses are a critical reservoir in antiretroviral therapy (ART)-treated subjects. These cells express little to no viral protein, and thus neither die by viral cytopathic effects, nor are efficiently cleared by immune effectors. Elimination of this reservoir is theoretically possible by combining latency-reversing agents (LRAs) with immune effectors, such as CD8+ T-cells. However, the relative efficacy of different LRAs in sensitizing latently-infected cells for recognition by HIV-specific CD8+ T-cells has not been determined. To address this, we developed an assay that utilizes HIV-specific CD8+ T-cell clones as biosensors for HIV antigen expression. By testing multiple CD8+ T-cell clones against a primary cell model of HIV latency, we identified several single agents that primed latently-infected cells for CD8+ T-cell recognition, including IL-2, IL-15, two IL-15 superagonists (IL-15SA and ALT-803), prostratin, and the TLR-2 ligand Pam3CSK4. In contrast, we did not observe CD8+ T-cell recognition of target cells following treatment with histone deacetylase inhibitors or with hexamethylene bisacetamide (HMBA). In further experiments we demonstrate that a clinically achievable concentration of the IL-15 superagonist 'ALT-803', an agent presently in clinical trials for solid and hematological tumors, primes the natural ex vivo reservoir for CD8+ T-cell recognition. Thus, our results establish a novel experimental approach for comparative evaluation of LRAs, and highlight ALT-803 as an LRA with the potential to synergize with CD8+ T-cells in HIV eradication strategies.
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Antivirales/farmacología , Linfocitos T CD4-Positivos/virología , Infecciones por VIH/inmunología , Proteínas/farmacología , Linfocitos T Citotóxicos/inmunología , Latencia del Virus/efectos de los fármacos , Ensayo de Inmunoadsorción Enzimática , Ensayo de Immunospot Ligado a Enzimas , Citometría de Flujo , Humanos , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes de Fusión , Activación Viral/efectos de los fármacosRESUMEN
Protein arginylation is a posttranslational modification of both N-terminal amino acids of proteins and sidechain carboxylates and can be crucial for viability and physiology in higher eukaryotes. The lack of arginylation causes severe developmental defects in moss, affects the low oxygen response in Arabidopsis thaliana and is embryo lethal in Drosophila and in mice. Although several studies investigated impact and function of the responsible enzyme, the arginyl-tRNA protein transferase (ATE) in plants, identification of arginylated proteins by mass spectrometry was not hitherto achieved. In the present study, we report the identification of targets and interaction partners of ATE in the model plant Physcomitrella patens by mass spectrometry, employing two different immuno-affinity strategies and a recently established transgenic ATE:GUS reporter line (Schuessele et al., 2016 New Phytol. , DOI: 10.1111/nph.13656). Here we use a commercially available antibody against the fused reporter protein (ß-glucuronidase) to pull down ATE and its interacting proteins and validate its in vivo interaction with a class I small heatshock protein via Förster resonance energy transfer (FRET). Additionally, we apply and modify a method that already successfully identified arginylated proteins from mouse proteomes by using custom-made antibodies specific for N-terminal arginine. As a result, we identify four arginylated proteins from Physcomitrella patens with high confidence.Data are available via ProteomeXchange with identifier PXD003228 and PXD003232.
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Aminoaciltransferasas/metabolismo , Bryopsida/metabolismo , Proteínas de Plantas/metabolismo , Anticuerpos/metabolismo , Transferencia Resonante de Energía de Fluorescencia , Espectrometría de Masas , Proteínas de Plantas/química , Mapas de Interacción de Proteínas , Proteómica/métodosRESUMEN
Resting memory CD4+ T-cells harboring latent HIV proviruses represent a critical barrier to viral eradication. Histone deacetylase inhibitors (HDACis), such as suberanilohydroxamic acid (SAHA), romidepsin, and panobinostat have been shown to induce HIV expression in these resting cells. Recently, it has been demonstrated that the low levels of viral gene expression induced by a candidate HDACi may be insufficient to cause the death of infected cells by viral cytopathic effects, necessitating their elimination by immune effectors, such as cytotoxic T-lymphocytes (CTL). Here, we study the impact of three HDACis in clinical development on T-cell effector functions. We report two modes of HDACi-induced functional impairment: i) the rapid suppression of cytokine production from viable T-cells induced by all three HDACis ii) the selective death of activated T-cells occurring at later time-points following transient exposures to romidepsin or, to a lesser extent, panobinostat. As a net result of these factors, HDACis impaired CTL-mediated IFN-γ production, as well as the elimination of HIV-infected or peptide-pulsed target cells, both in liquid culture and in collagen matrices. Romidepsin exerted greater inhibition of antiviral function than SAHA or panobinostat over the dose ranges tested. These data suggest that treatment with HDACis to mobilize the latent reservoir could have unintended negative impacts on the effector functions of CTL. This could influence the effectiveness of HDACi-based eradication strategies, by impairing elimination of infected cells, and is a critical consideration for trials where therapeutic interruptions are being contemplated, given the importance of CTL in containing rebound viremia.
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Citotoxicidad Inmunológica/efectos de los fármacos , Depsipéptidos/farmacología , Infecciones por VIH/inmunología , Inhibidores de Histona Desacetilasas/farmacología , Ácidos Hidroxámicos/farmacología , Indoles/farmacología , Linfocitos T Citotóxicos/inmunología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Panobinostat , Linfocitos T Citotóxicos/efectos de los fármacos , Replicación Viral/efectos de los fármacosRESUMEN
The importance of the arginyl-tRNA protein transferase (ATE), the enzyme mediating post-translation arginylation of proteins in the N-end rule degradation (NERD) pathway of protein stability, was analysed in Physcomitrella patens and compared to its known functions in other eukaryotes. We characterize ATE:GUS reporter lines as well as ATE mutants in P. patens to study the impact and function of arginylation on moss development and physiology. ATE protein abundance is spatially and temporally regulated in P. patens by hormones and light and is highly abundant in meristematic cells. Further, the amount of ATE transcript is regulated during abscisic acid signalling and downstream of auxin signalling. Loss-of-function mutants exhibit defects at various levels, most severely in developing gametophores, in chloroplast starch accumulation and senescence. Thus, arginylation is necessary for moss gametophyte development, in contrast to the situation in flowering plants. Our analysis further substantiates the conservation of the N-end rule pathway components in land plants and highlights lineage-specific features. We introduce moss as a model system to characterize the role of the NERD pathway as an additional layer of complexity in eukaryotic development.
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Aminoaciltransferasas/metabolismo , Tipificación del Cuerpo , Bryopsida/enzimología , Bryopsida/crecimiento & desarrollo , Células Germinativas de las Plantas/crecimiento & desarrollo , Arabidopsis/metabolismo , Tipificación del Cuerpo/genética , Bryopsida/genética , Bryopsida/ultraestructura , Clorofila/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestructura , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Mutación/genética , Especificidad de Órganos , Fenotipo , Desarrollo de la Planta , Reacción en Cadena en Tiempo Real de la Polimerasa , Almidón/metabolismo , Fracciones Subcelulares/metabolismoRESUMEN
Extant eukaryotes are highly compartmentalized and have integrated endosymbionts as organelles, namely mitochondria and plastids in plants. During evolution, organellar proteomes are modified by gene gain and loss, by gene subfunctionalization and neofunctionalization, and by changes in protein targeting. To date, proteomics data for plastids and mitochondria are available for only a few plant model species, and evolutionary analyses of high-throughput data are scarce. We combined quantitative proteomics, cross-species comparative analysis of metabolic pathways, and localizations by fluorescent proteins in the model plant Physcomitrella patens in order to assess evolutionary changes in mitochondrial and plastid proteomes. This study implements data-mining methodology to classify and reliably reconstruct subcellular proteomes, to map metabolic pathways, and to study the effects of postendosymbiotic evolution on organellar pathway partitioning. Our results indicate that, although plant morphologies changed substantially during plant evolution, metabolic integration of organelles is largely conserved, with exceptions in amino acid and carbon metabolism. Retargeting or regulatory subfunctionalization are common in the studied nucleus-encoded gene families of organelle-targeted proteins. Moreover, complementing the proteomic analysis, fluorescent protein fusions revealed novel proteins at organelle interfaces such as plastid stromules (stroma-filled tubules) and highlight microcompartments as well as intercellular and intracellular heterogeneity of mitochondria and plastids. Thus, we establish a comprehensive data set for mitochondrial and plastid proteomes in moss, present a novel multilevel approach to organelle biology in plants, and place our findings into an evolutionary context.
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Bryopsida/metabolismo , Compartimento Celular , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Proteómica/métodos , Evolución Biológica , Análisis por Conglomerados , Técnicas de Sustitución del Gen , Redes y Vías Metabólicas , Mitocondrias/metabolismo , Análisis Multivariante , Plastidios/metabolismo , Coloración y Etiquetado , Fracciones Subcelulares/metabolismo , SimbiosisRESUMEN
The fruit fly Drosophila melanogaster is a good model to unravel the molecular mechanisms of innate immunity and has led to some important discoveries about the sensing and signaling of microbial infections. The response of Drosophila to virus infections remains poorly characterized and appears to involve two facets. On the one hand, RNA interference involves the recognition and processing of dsRNA into small interfering RNAs by the host RNase Dicer-2 (Dcr-2), whereas, on the other hand, an inducible response controlled by the evolutionarily conserved JAK-STAT pathway contributes to the antiviral host defense. To clarify the contribution of the small interfering RNA and JAK-STAT pathways to the control of viral infections, we have compared the resistance of flies wild-type and mutant for Dcr-2 or the JAK kinase Hopscotch to infections by seven RNA or DNA viruses belonging to different families. Our results reveal a unique susceptibility of hop mutant flies to infection by Drosophila C virus and cricket paralysis virus, two members of the Dicistroviridae family, which contrasts with the susceptibility of Dcr-2 mutant flies to many viruses, including the DNA virus invertebrate iridescent virus 6. Genome-wide microarray analysis confirmed that different sets of genes were induced following infection by Drosophila C virus or by two unrelated RNA viruses, Flock House virus and Sindbis virus. Overall, our data reveal that RNA interference is an efficient antiviral mechanism, operating against a large range of viruses, including a DNA virus. By contrast, the antiviral contribution of the JAK-STAT pathway appears to be virus specific.
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Drosophila melanogaster/genética , Drosophila melanogaster/inmunología , Interferencia de ARN/inmunología , Alphavirus/inmunología , Infecciones por Alphavirus/genética , Infecciones por Alphavirus/inmunología , Infecciones por Alphavirus/prevención & control , Animales , Animales Modificados Genéticamente , Infecciones por Virus ADN/genética , Infecciones por Virus ADN/inmunología , Infecciones por Virus ADN/prevención & control , Proteínas de Drosophila/genética , Proteínas de Drosophila/inmunología , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/virología , Regulación de la Expresión Génica , Quinasas Janus/metabolismo , Masculino , Nodaviridae/inmunología , ARN Helicasas/genética , ARN Helicasas/inmunología , Infecciones por Virus ARN/genética , Infecciones por Virus ARN/inmunología , Infecciones por Virus ARN/prevención & control , Ribonucleasa III/genética , Ribonucleasa III/inmunología , Factores de Transcripción/metabolismoRESUMEN
BACKGROUND AND OBJECTIVES: Histopathologic studies have identified immunoglobulin (Ig) deposition and complement activation as contributors of CNS tissue damage in multiple sclerosis (MS). Intrathecal IgM synthesis is associated with higher MS disease activity and severity, and IgM is the strongest complement-activating immunoglobulin. In this study, we investigated whether complement components (CCs) and complement activation products (CAPs) are increased in persons with MS, especially in those with an intrathecal IgM synthesis, and whether they are associated with disease severity and progression. METHODS: CC and CAP levels were quantified in plasma and CSF of 112 patients with clinically isolated syndrome (CIS), 127 patients with MS (90 relapsing-remitting, 14 primary progressive, and 23 secondary progressive), 31 inflammatory neurologic disease, and 44 symptomatic controls from the Basel CSF databank study. Patients with CIS/MS were followed in the Swiss MS cohort study (median 6.3 years). Levels of CC/CAP between diagnosis groups were compared; in CIS/MS, associations of CC/CAP levels with intrathecal Ig synthesis, baseline Expanded Disability Status Scale (EDSS) scores, MS Severity Score (MSSS), and neurofilament light chain (NfL) levels were investigated by linear regression, adjusted for age, sex, and albumin quotient. RESULTS: CSF (but not plasma) levels of C3a, C4a, Ba, and Bb were increased in patients with CIS/MS, being most pronounced in those with an additional intrathecal IgM production. In CIS, doubling of C3a and C4a in CSF was associated with 0.31 (CI 0.06-0.56; p = 0.016) and 0.32 (0.02-0.62; p = 0.041) increased EDSS scores at lumbar puncture. Similarly, doubling of C3a and Ba in CIS/MS was associated with 0.61 (0.19-1.03; p < 0.01) and 0.74 (0.18-1.31; p = 0.016) increased future MSSS. In CIS/MS, CSF levels of C3a, C4a, Ba, and Bb were associated with increased CSF NfL levels, e.g., doubling of C3a was associated with an increase of 58% (Est. 1.58; CI 1.37-1.81; p < 0.0001). DISCUSSION: CNS-compartmentalized activation of the classical and alternative pathways of complement is increased in CIS/MS and associated with the presence of an intrathecal IgM production. Increased complement activation within the CSF correlates with EDSS, future MSSS, and NfL levels, supporting the concept that complement activation contributes to MS pathology and disease progression. Complement inhibition should be explored as therapeutic target to attenuate disease severity and progression in MS.
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Enfermedades Desmielinizantes , Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Humanos , Estudios de Cohortes , Gravedad del Paciente , Activación de Complemento , Inmunoglobulina MRESUMEN
Activation of innate antiviral responses in multicellular organisms relies on the recognition of structural differences between viral and cellular RNAs. Double-stranded (ds)RNA, produced during viral replication, is a well-known activator of antiviral defenses and triggers interferon production in vertebrates and RNAi in invertebrates and plants. Previous work in mammalian cells indicates that negative-strand RNA viruses do not appear to generate dsRNA, and that activation of innate immunity is triggered by the recognition of the uncapped 5' ends of viral RNA. This finding raises the question whether antiviral RNAi, which is triggered by the presence of dsRNA in insects, represents an effective host-defense mechanism against negative-strand RNA viruses. Here, we show that the negative-strand RNA virus vesicular stomatitis virus (VSV) does not produce easily detectable amounts of dsRNA in Drosophila cells. Nevertheless, RNAi represents a potent response to VSV infection, as illustrated by the high susceptibility of RNAi-defective mutant flies to this virus. VSV-derived small RNAs produced in infected cells or flies uniformly cover the viral genome, and equally map the genome and antigenome RNAs, indicating that they derive from dsRNA. Our findings reveal that RNAi is not restricted to the defense against positive-strand or dsRNA viruses but can also be highly efficient against a negative-strand RNA virus. This result is of particular interest in view of the frequent transmission of medically relevant negative-strand RNA viruses to humans by insect vectors.
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Inmunidad Innata/genética , Interferencia de ARN/inmunología , Vesiculovirus/inmunología , Animales , Línea Celular , Drosophila/virología , Genoma Viral , Insectos Vectores , Virus ARN/inmunología , ARN Bicatenario/análisis , ARN ViralRESUMEN
BACKGROUND: Preregistration, the open science practice of specifying and registering details of a planned study prior to knowing the data, increases the transparency and reproducibility of research. Large-scale replication attempts for psychological results yielded shockingly low success rates and contributed to an increasing demand for open science practices among psychologists. However, preregistering one's studies is still not the norm in the field. Here, we conducted a study to explore possible reasons for this discrepancy. METHODS: In a mixed-methods approach, we conducted an online survey assessing attitudes, motivations, and perceived obstacles with respect to preregistration. Respondents (N = 289) were psychological researchers that were recruited through their publications on Web of Science, PubMed, PSYNDEX, and PsycInfo, and preregistrations on OSF Registries. Based on the theory of planned behavior, we predicted that positive attitudes (moderated by the perceived importance of preregistration) as well as a favorable subjective norm and higher perceived behavioral control positively influence researchers' intention to preregister (directional hypothesis 1). Furthermore, we expected an influence of research experience on attitudes and perceived motivations and obstacles regarding preregistration (non-directional hypothesis 2). We analyzed these hypotheses with multiple regression models and included preregistration experience as a control variable. RESULTS: Researchers' attitudes, subjective norms, perceived behavioral control, and the perceived importance of preregistration significantly predicted researchers' intention to use preregistration in the future (see hypothesis 1). Research experience influenced both researchers' attitudes and their perception of motivations to preregister, but not the perception of obstacles (see hypothesis 2). Descriptive reports on researchers' attitudes, motivations and obstacles regarding preregistration are provided. DISCUSSION: Many researchers had already preregistered and had a rather positive attitude toward preregistration. Nevertheless, several obstacles were identified that may be addressed to improve and foster preregistration.
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Actitud , Intención , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Control de la ConductaRESUMEN
The ubiquitin-like modifier FAT10 is highly upregulated under inflammatory conditions and targets its conjugation substrates to the degradation by the 26S proteasome. This process termed FAT10ylation is mediated by an enzymatic cascade and includes the E1 activating enzyme ubiquitin-like modifier activating enzyme 6 (UBA6), the E2 conjugating enzyme UBA6-specific E2 enzyme 1 (USE1) and E3 ligases, such as Parkin. In this study, the function of the HECT-type ubiquitin E3 ligase HUWE1 was investigated as a putative E3 ligase and/or conjugation substrate of FAT10. Our data provide strong evidence that HUWE1 is FAT10ylated in a UBA6 and FAT10 diglycine-dependent manner in vitro and in cellulo and that the HUWE1-FAT10 conjugate is targeted to proteasomal degradation. Since the mutation of all relevant cysteine residues within the HUWE1 HECT domain did not abolish FAT10 conjugation, a role of HUWE1 as E3 ligase for FAT10ylation is rather unlikely. Moreover, we have identified the autophagy-related protein AMBRA1 as a new FAT10 interaction partner. We show that the HUWE1-FAT10 conjugate formation is diminished in presence of AMBRA1, while the interaction between AMBRA1 and HUWE1 is strengthened in presence of FAT10. This implies a putative interplay of all three proteins in cellular processes such as mitophagy.