Publications search

Uveal melanoma is the most common eye cancer in adults and is clinically and genetically distinct from skin cutaneous melanoma. In a subset of cases, the oncogenic driver is an activating mutation in CYSLTR2, the gene encoding the G protein-coupled receptor cysteinyl-leukotriene receptor 2 (CysLTR2). The mutant CYSLTR2 encodes for the CysLTR2-L129Q receptor, with the substitution of Leu to Gln at position 129 (3.43). The ability of CysLTR2-L129Q to cause malignant transformation has been hypothesized to result from constitutive activity, but how the receptor could escape desensitization is unknown. Here, we characterize the functional properties of CysLTR2-L129Q. We show that CysLTR2-L129Q is a constitutively active mutant that strongly drives Gq/11 signaling pathways. However, CysLTR2-L129Q only poorly recruits beta-arrestin. Using a modified Slack-Hall operational model, we quantified the constitutive activity for both pathways and conclude that CysLTR2-L129Q displays profound signaling bias for Gq/11 signaling pathways while escaping beta-arrestin-mediated down-regulation. CYSLTR2 is the first known example of a G protein-coupled receptor driver oncogene that encodes a highly biased constitutively active mutant receptor. These results provide new insights into the mechanism of CysLTR2-L129Q oncoprotein signaling and suggest CYSLTR2 as a promising potential therapeutic target in uveal melanoma.

Objectives Impairment of type I interferon (IFN-I) immunity has been reported in critically ill COVID-19 patients. This defect can be explained in a subset of patients by the presence of circulating autoantibodies (auto-Abs) against IFN-I. We set out to improve the detection and the quantification of IFN-I auto-Abs in a cohort of critically ill COVID-19 patients, in order to better evaluate the prevalence of these Abs as the pandemic progresses, and how they correlate with the clinical course of the disease. Methods The concentration of anti-IFN-alpha(2) Abs was determined in the serum of 84 critically ill COVID-19 patients who were admitted to ICU in Hospices Civils de Lyon, France, using a commercially available kit (Thermo Fisher, Catalog #BMS217). Results A total of 21 of 84 (25%) critically ill COVID-19 patients had circulating anti-IFN-alpha(2) Abs above cut-off (> 34 ng mL(-1)). Among them, 15 of 21 had Abs with neutralising activity against IFN-alpha(2), that is 15 of 84 (18%) critically ill patients. In addition, we noticed an impairment of the IFN-I response in the majority of patients with neutralising anti-IFN-alpha(2) Abs. There was no significant difference in the clinical characteristics or outcome of with or without neutralising anti-IFN-alpha(2) auto-Abs. We detected anti-IFN-alpha(2) auto-Abs in COVID-19 patients' sera throughout their ICU stay. Finally, we also found auto-Abs against multiple subtypes of IFN-I including IFN-omega. Conclusions We reported that 18% of critically ill COVID-19 patients were positive for IFN-I auto-Abs, whereas all mild COVID-19 patients were negative, confirming that the presence of these antibodies is associated with a higher risk of developing a critical COVID-19 form.

Viruses in the family Retroviridae are found in a wide variety of vertebrate hosts. Enveloped virions are 80-100 nm in diameter with an inner core containing the viral genome and replicative enzymes. Core morphology is often characteristic for viruses within the same genus. Replication involves reverse transcription and integration into host cell DNA, resulting in a provirus. Integration into germline cells can result in a heritable provirus known as an endogenous retrovirus. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Retroviridae, which is available at ictv.global/ report/retroviridae.

A disintegrin and metalloprotease 17 (ADAM17) is a cellsurface metalloprotease that serves as the principle sheddase for tumor necrosis factor alpha (TNF alpha), interleukin-6 receptor (IL6R), and several ligands of the epidermal growth factor receptor (EGFR), regulating these crucial signaling pathways. ADAM17 activation requires its transmembrane domain, but not its cytoplasmic domain, and little is known about the role of this domain in vivo. To investigate, we used CRISPR-Cas9 to mutate the endogenous Adam17 locus in mice to produce a mutant ADAM17 lacking its cytoplasmic domain (Adam17 Delta cyto). Homozygous Adam17 Delta cyto animals were born at a Mendelian ratio and survived into adulthood with slightly wavy hair and curled whiskers, consistent with defects in ADAM17/EGFR signaling. At birth, Adam17 Delta cyto mice resembled Adam17-/- mice in that they had open eyes and enlarged semilunar heart valves, but they did not have bone growth plate defects. The deletion of the cytoplasmic domain resulted in strongly decreased ADAM17 protein levels in all tissues and cells examined, providing a likely cause for the hypomorphic phenotype. In functional assays, Adam17 Delta cyto mouse embryonic fibroblasts and bone-marrow-derived macrophages had strongly reduced ADAM17 activity, consistent with the reduced protein levels. Nevertheless, ADAM17 Delta cyto could be stimulated by PMA, a well-characterized posttranslational activator of ADAM17, corroborating that the cytoplasmic domain of endogenous ADAM17 is not required for its rapid response to PMA. Taken together, these results provide the first evidence that the cytoplasmic domain of ADAM17 plays a pivotal role in vivo in regulating ADAM17 levels and function.

This is the second article in a new series on clinical research by nurses. The series is designed to give nurses the knowledge and skills they need to participate in research, step by step. Each column will present the concepts that underpin evidence-based practice-from research design to data interpretation. The articles will also be accompanied by a podcast offering more insight and context from the author.

Gordon Moore famously observed that the number of transistors in state-of-the-art integrated circuits (units per chip) increases exponentially, doubling every 12-24 months. Analysts have debated whether simple exponential growth describes the dynamics of computer processor evolution. We note that the increase encompasses two related phenomena, integration of larger numbers of transistors and transistor miniaturization. Growth in the number of transistors per unit area, or chip density, allows examination of the evolution with a single measure. Density of Intel processors between 1959 and 2013 are consistent with a biphasic sigmoidal curve with characteristic times of 9.5 years. During each stage, transistor density increased at least tenfold within approximately six years, followed by at least three years with negligible growth rates. The six waves of transistor density increase account for and give insight into the underlying processes driving advances in processor manufacturing and point to future limits that might be overcome.

OBJECTIVE: To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS: Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1-8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9-10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS: Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS: The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.

Baker's yeast, Saccharomyces cerevisiae, is a versatile system for expression of recombinant eukaryotic proteins. This system is simple to use and does not require extraordinary expertise nor tissue culture facilities. Proteins expressed in the yeast system provide eukaryotic post-translational modifications, making it superior to bacterial expression for factors that require post-translational modification. In addition, it is quite simple to co-express multiple genes at the same time, for recombinant production of large multi-protein complexes. In this chapter, we provide protocols for inducible expression of recombinant genes from episomal plasmid vectors, and protocols for integration of the recombinant genes into the chromosomes of yeast, which enables simple rapid growth of expression cells and induction of recombinant protein complexes in non-selectable rich media.

The automation and improvement of nano-scale electron microscopy imaging technologies have expanded a push in neuroscience to understand brain circuits at the scale of individual cells and their connections. Most of this research effort, called 'connectomics', has been devoted to handling, processing, and segmenting large-scale image data to reconstruct graphs of neuronal connectivity. However, connectomics datasets contain a wealth of high-resolution information about the brain that could be leveraged to understand its detailed anatomy beyond just the connections between neurons, such as cell morphologies and distributions. This study introduces a novel visualization system, ZeVis, for the interactive exploration of a whole larval zebrafish brain using a terabyte-scale serial-section electron microscopy dataset. ZeVis combines 2D cross-sectional views and 3D volumetric visualizations of the input serial-section electron microscopy data with overlaid segmentation results to facilitate the analyses of various brain structures and their interpretations. The system also provides a graph-based data processing interface to generate subsets of feature segmentation data easily. The segmentation data can be filtered by morphological features or anatomical constraints, allowing statistical analysis and comparisons across regions. We applied ZeVis to actual data of a terabyte-scale whole-brain larval zebrafish and analyzed cell nucleus distributions in several anatomical regions.

The development of safe and effective vaccines against viruses is central to disease control. With advancements in DNA synthesis technology, the production of synthetic viral genomes has fueled many research efforts that aim to generate attenuated viruses by introducing synonymous mutations. Elucidation of the mechanisms underlying virus attenuation through synonymous mutagenesis is revealing interesting new biology that can be exploited for vaccine development. Here, we review recent advancements in this field of synthetic virology and focus on the molecular mechanisms of attenuation by genetic recoding of viruses. We highlight the action of the zinc finger antiviral protein (ZAP) and RNase L, two proteins involved in the inhibition of viruses enriched for CpG and UpA dinucleotides, that are often the products of virus recoding algorithms. Additionally, we discuss current challenges in the field as well as studies that may illuminate how other host functions, such as translation, are potentially involved in the attenuation of recoded viruses.