The ongoing COVID-19 pandemic has caused an unprecedented global health crisis. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19. Subversion of host ...protein synthesis is a common strategy that pathogenic viruses use to replicate and propagate in their host. In this study, we show that SARS-CoV-2 is able to shut down host protein synthesis and that SARS-CoV-2 nonstructural protein NSP14 exerts this activity. We show that the translation inhibition activity of NSP14 is conserved in human coronaviruses. NSP14 is required for virus replication through contribution of its exoribonuclease (ExoN) and N7-methyltransferase (N7-MTase) activities. Mutations in the ExoN or N7-MTase active sites of SARS-CoV-2 NSP14 abolish its translation inhibition activity. In addition, we show that the formation of NSP14-NSP10 complex enhances translation inhibition executed by NSP14. Consequently, the translational shutdown by NSP14 abolishes the type I interferon (IFN-I)-dependent induction of interferon-stimulated genes (ISGs). Together, we find that SARS-CoV-2 shuts down host innate immune responses via a translation inhibitor, providing insights into the pathogenesis of SARS-CoV-2.
Flaviviruses continue to emerge as global health threats. There are currently no Food and Drug Administration (FDA) approved antiviral treatments for flaviviral infections. Therefore, there is a ...pressing need to identify host and viral factors that can be targeted for effective therapeutic intervention. Type I interferon (IFN-I) production in response to microbial products is one of the host's first line of defense against invading pathogens. Cytidine/uridine monophosphate kinase 2 (CMPK2) is a type I interferon-stimulated gene (ISG) that exerts antiviral effects. However, the molecular mechanism by which CMPK2 inhibits viral replication is unclear. Here, we report that CMPK2 expression restricts Zika virus (ZIKV) replication by specifically inhibiting viral translation and that IFN-I- induced CMPK2 contributes significantly to the overall antiviral response against ZIKV. We demonstrate that expression of CMPK2 results in a significant decrease in the replication of other pathogenic flaviviruses including dengue virus (DENV-2), Kunjin virus (KUNV) and yellow fever virus (YFV). Importantly, we determine that the N-terminal domain (NTD) of CMPK2, which lacks kinase activity, is sufficient to restrict viral translation. Thus, its kinase function is not required for CMPK2's antiviral activity. Furthermore, we identify seven conserved cysteine residues within the NTD as critical for CMPK2 antiviral activity. Thus, these residues may form an unknown functional site in the NTD of CMPK2 contributing to its antiviral function. Finally, we show that mitochondrial localization of CMPK2 is required for its antiviral effects. Given its broad antiviral activity against flaviviruses, CMPK2 is a promising potential pan-flavivirus inhibitor.
The Eastern Equine Encephalitis Virus (EEEV) is an emerging public health threat, with the number of reported cases in the US increasing in recent years. EEEV is a BSL3 pathogen, and the North ...American strain is a US Federal Select Agent (SA). These restrictions make experiments with EEEV difficult to perform, as high-tech equipment is often unavailable in BSL3 spaces and due to concerns about generating aerosols during manipulations. Therefore, a range of inactivation methods suitable for different downstream analysis methods are essential for advancing research on EEEV. We used heat, chemical, and ultraviolet (UV)-based methods for the inactivation of infected cells and supernatants infected with the non-select agent Madariaga virus (MADV). Although the MADV and EEEV strains are genetically distinct, differing by 8-11% at the amino acid level, they are expected to be similarly susceptible to various inactivation methods. We determined the following to be effective methods of inactivation: heat, TRIzol LS, 4% PFA, 10% formalin, and UV radiation for infected supernatants; TRIzol, 2.5% SDS with BME, 0.2% NP40, 4% PFA, and 10% formalin for infected cells. Our results have the potential to expand the types and complexity of experiments and analyses performed by EEEV researchers.
Innate immune responses induce hundreds of interferon-stimulated genes (ISGs). Viperin, a member of the radical S-adenosyl methionine (SAM) superfamily of enzymes, is the product of one such ISG that ...restricts the replication of a broad spectrum of viruses. Here, we report a previously unknown antiviral mechanism in which viperin activates a ribosome collision-dependent pathway that inhibits both cellular and viral RNA translation. We found that the radical SAM activity of viperin is required for translation inhibition and that this is mediated by viperin’s enzymatic product, 3′-deoxy-3′,4′-didehydro-CTP (ddhCTP). Viperin triggers ribosome collisions and activates the MAPKKK ZAK pathway that in turn activates the GCN2 arm of the integrated stress response pathway to inhibit translation. The study illustrates the importance of translational repression in the antiviral response and identifies viperin as a translation regulator in innate immunity.
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•Viperin regulates cellular translation to restrict viral translation and replication•Viperin activates the GCN2-arm of the ISR•Viperin induces ribosome collision-mediated translation inhibition•Viperin’s product ddhCTP induces ribosome collision
Hsu et al. show that viperin, a broad-spectrum antiviral protein, inhibits the viral replication of two medically relevant flaviviruses by limiting viral protein production. Viperin synthesizes a nucleoside derivative, ddhCTP, which induces ribosome collisions, leading to the activation of the integrated stress response and consequently translation inhibition.
Plastic litter is widespread on our planet and is recognized as a contaminant of high concern. Plastic ingestion and retention in gills were studied in two key Baltic fish species: herring (Clupea ...harengus L.) and cod (Gadus morhua L.). In total, 183 fish from the southern Baltic Sea were analysed. Plastic litter was found in digestive tracts of 12.7 and 14.8% of herrings and cods, respectively. In addition, gills were shown to constitute an important transfer route of plastic to cod (9.9% of cods) but not to herring thus likely reflecting species-specific differences in fish lifestyles and/or water filtering capacity. No more than one plastic item per individual was found except for three fish with two items in their stomachs. Dominant microplastics (<5 mm) (MPs) (88.6% of all items) composed of irregular fragments, fibres and foils (61.3%, 25.8% and 12.9% of all MPs, respectively) were followed by meso- (5–25 mm) and macro-plastics (>25 mm) (5.7% each of all items). Plastic ingestion and retention in gills did not affect fish body condition assessed by Fulton's K index, although herrings that ingested plastic particles beyond the microplastic size range (i.e. >5 mm) were characterized by the lowest condition indices.
All plastic items recovered from fish exhibited clear signs of weathering and surface extended due to their roughness and fragmentation which may enhance both sorption properties for chemical compounds and/or their leaching. Nevertheless, chemical contaminant levels in herring muscles were not different than in a plastic-free group.
The vast majority of fibres found in fish was identified as air-borne or procedural contamination and were excluded from further analyses. In addition, the vessel's paint dust found in fish stressed the need for strict quality assurance also during fish sampling.
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•Microplastics dominate over other plastic size fractions in fish stomachs and gills.•Similar plastic ingestion frequency in pelagic and demersal fish•Plastic retention on gills of demersal species•Body condition and contaminant levels unrelated to plastic occurrence in fish•Strict quality assurance during both laboratory and field work is needed.
A recent view on schizophrenia phenomenology underlines the impaired relations between the mind and the body. An aberrant feeling of ipseity may be the real source of suffering of the patients from ...psychosis and impacts general symptomatology. The disturbed connection between thinking processes and environmental stimuli may lead to language disembodiment. In the study, we aimed to experimentally test the presence of disembodied language and investigate its association with symptoms of psychosis in adolescents diagnosed with early-onset schizophrenia spectrum disorders. Assessment of language embodiment was conducted using the Zabór Verbal Task (ZVT) with concurrent linguistic and clinical assessment using the Thought, Language, and Communication Scale (TLCS) and Positive and Negative Symptoms Scale (PANSS). The study group of patients (
n
= 31) aged 11–18 years, with the diagnosis of schizophrenia spectrum according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and the International Classification of Diseases (ICD-10) criteria, was compared with a sex- and age-matched healthy control sample (
n
= 31). Patients with psychosis made more errors in ZVT than healthy controls (
p
= 0.01) and this parameter did not improve after 6–8 weeks of standard treatment (
p
= 0.55). A higher number of errors in ZVT were associated with the presence of auditory hallucinations (odds ratio OR 1.14; 95% CI 1.02–1.26). ZVT errors coincided with perception disorders, alternatively to the TLCS scores where we observed association with abnormal beliefs. The results of these preliminary studies indicate the value of the phenomenological approach in the diagnosis of schizophrenia spectrum and suggest a potential involvement of language disembodiment in symptomatology.
Abstract
Mood disorders have been discussed as being in relation to glial pathology. S100B is a calcium-binding protein, and a marker of glial dysfunctions. Although alterations in the S100B ...expression may play a role in various central nervous system diseases, there are no studies on the potential role of S100B in mood disorders in adolescents and young adults . In a prospective two-year follow-up study, peripheral levels of S100B were investigated in 79 adolescent/young adult patients (aged 14–24 years), diagnosed with mood disorders and compared with 31 healthy control subjects. A comprehensive clinical interview was conducted which focused on clinical symptoms and diagnosis change. The diagnosis was established and verified at each control visit. Serum S100B concentrations were determined. We detected: lower S100B levels in medicated patients, compared with those who were drug-free, and healthy controls; higher S100B levels in a depressed group with a family history of affective disorder; correlations between age and medication status; sex-dependent differences in S100B levels; and lack a of correlation between the severity of depressive or hypo/manic symptoms. The results of our study indicate that S100B might be a trait-dependent rather than a state-dependent marker. Due to the lack of such studies in the youth population, further research should be performed. A relatively small sample size, a lack of exact age-matched control group, a high drop-out rate.
Phenotypic screening is making a comeback in drug discovery as the maturation of chemical proteomics methods has facilitated target identification for bioactive small molecules. A limitation of these ...approaches is that time-consuming genetic methods or other means are often required to determine the biologically relevant target (or targets) from among multiple protein-compound interactions that are typically detected. Here, we have combined phenotypic screening of a directed small-molecule library with competitive activity-based protein profiling to map and functionally characterize the targets of screening hits. Using this approach, we identify carboxylesterase 3 (Ces3, also known as Ces1d) as a primary molecular target of bioactive compounds that promote lipid storage in adipocytes. We further show that Ces3 activity is markedly elevated during adipocyte differentiation. Treatment of two mouse models of obesity-diabetes with a Ces3 inhibitor ameliorates multiple features of metabolic syndrome, illustrating the power of the described strategy to accelerate the identification and pharmacologic validation of new therapeutic targets.
Metabolic syndrome (MS) is a growing social, economic, and health problem. MS coexists with nearly half of all patients with affective disorders. This study aimed to evaluate the neurobiological ...parameters (clinical, anthropometric, biochemical, adipokines levels, and ultrasound of carotid arteries) and their relationship with the development of MS in patients with bipolar disorder. The study group consisted of 70 patients (50 women and 20 men) hospitalized due to episodes of depression in the course of bipolar disorders. The Hamilton Depression Rating Scale was used to assess the severity of the depression symptoms in an acute state of illness and after six weeks of treatment. The serum concentration of adipokines was determined using an ELISA method. The main finding of this study is that the following adipokines correlated with MS in the bipolar depression women group: visfatin, S100B, and leptin had a positive correlation, whereas adiponectin, leptin-receptor, and adiponectin/leptin ratio showed a negative correlation. Moreover, the adiponectin/leptin ratio showed moderate to strong negative correlation with insulin level, BMI, waist circumference, triglyceride level, treatment with metformin, and a positive moderate correlation with HDL. The adiponectin/leptin ratio may be an effective tool to assess MS in depressed female bipolar patients.
Cod was one of the most important fish species in the Baltic Sea, but its condition is deteriorating for several reasons, including an increasing parasite burden. The aim of this study was to ...determine the source of infection of Baltic cod with parasites by examination of invertebrates found in situ in the cod stomach. A total of 1681 cod were sampled during four research cruises in the southern Baltic Sea in 2012, 2013 and 2014 and the composition of their diet was analysed. Each prey item from cod stomach was identified to the lowest possible taxonomic level and a parasitological analysis of all invertebrates collected was performed. Crangon crangon, Saduria entomon and Mysis mixta were the most commonly represented invertebrates among food items. Hysterothylacium aduncum was found only in C. crangon. This host–parasite system is reported here for the first time in situ in the stomach of cod from the Baltic Sea, confirming the role of C. crangon in cod infection with H. aduncum.
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