The Genetic Profiles of TIF1 and TIF2 Duplicate Genes

As one of the key steps in protein synthesis, translation initiation is subjected to multi-level regulation which is achieved via diverse mechanisms. The cell adjusts protein synthesis accordingly to its status and environment. The degree of contribution of the processes involved in the regulation of translation initiation is still poorly understood. The first part of this study focuses on identifying mechanisms of regulation in a translationally deficient yeast system, impaired by the loss of one or the other of the TIF1/2 duplicate genes, which together code for the eukaryotic initiation factor 4A (eIF4A). A major finding of this research is related to the functional competences associated with the two duplicate members of the gene pair. Although the genetic profile associated with TIF1 highlights a connection with transcriptional process, the majority of transcription-translation inter-talk is allocated with TIF2, along with a dense network of genetic interactions surrounding the SAGA complex. TIF2 is also the only paralog devoted to interactions with a substantial group of functionally related genes involved in early meiotic gene expression. Protein degradation in the global control of protein synthesis represents a fundamental process and accounts for diverse points of control, in particular through ubiquitination/deubiquitination. This research concludes that functional turnover of proteins and the translation/transcription inter-talk emerges as the most significant contributors to the sophistically regulated translational regulation, The second part of this study aims to determine the extent of similarity and divergence between the TIF1 and TIF2 paralogs. Growth of their individual deletion strains was challenged under different chemical and environmental conditions with the intent to explore the relative contributions of each duplicate in response to an extend range of perturbations. The pair of duplicates appeared convincingly robust in coping with these adversities under disparate cellular contexts, thus suggesting a highly conserved and backed-up genetic network. One of the primary treatments made use of lithium, a condition which was hoped to help, along with furthering our understanding of the TIF1 and TIF2 networks, in formulating an explanation on how augmented translation initiation overcomes lithium toxicity. Although this approach did not return results that could be used to address this unresolved topic, evaluation of genetic inhibition and suppression was highly instructive regarding the mechanisms of response triggered upon lithium/galactose stress. Regulation and synchronization of basic cellular processes were affected: emphasis brought on aspects of cell communication highlighted mechanisms articulated by kinase enzymes and the importance of repression of cell cycle progression in control of protein synthesis. Data from the screen also indicated the stress that combined lithium/galactose treatment places on central metabolic pathways, for instance those between the Leloir, gluconeogenesis, and trehalose pathways

New Cases and Mutations in SEC23B Gene Causing Congenital Dyserythropoietic Anemia Type II

Hereditary anemias; Ineffective erythropoiesis; Rare blood diseaseAnèmies hereditàries; Eritropoesi ineficaç; Malaltia rara de la sangAnemias hereditarias; Eritropoyesis ineficaz; Enfermedad rara de la sangreCongenital dyserythropoietic anemia type II (CDA II) is an inherited autosomal recessive blood disorder which belongs to the wide group of ineffective erythropoiesis conditions. It is characterized by mild to severe normocytic anemia, jaundice, and splenomegaly owing to the hemolytic component. This often leads to liver iron overload and gallstones. CDA II is caused by biallelic mutations in the SEC23B gene. In this study, we report 9 new CDA II cases and identify 16 pathogenic variants, 6 of which are novel. The newly reported variants in SEC23B include three missenses (p.Thr445Arg, p.Tyr579Cys, and p.Arg701His), one frameshift (p.Asp693GlyfsTer2), and two splicing variants (c.1512-2A>G, and the complex intronic variant c.1512-3delinsTT linked to c.1512-16_1512-7delACTCTGGAAT in the same allele). Computational analyses of the missense variants indicated a loss of key residue interactions within the beta sheet and the helical and gelsolin domains, respectively. Analysis of SEC23B protein levels done in patient-derived lymphoblastoid cell lines (LCLs) showed a significant decrease in SEC23B protein expression, in the absence of SEC23A compensation. Reduced SEC23B mRNA expression was only detected in two probands carrying nonsense and frameshift variants; the remaining patients showed either higher gene expression levels or no expression changes at all. The skipping of exons 13 and 14 in the newly reported complex variant c.1512-3delinsTT/c.1512-16_1512-7delACTCTGGAAT results in a shorter protein isoform, as assessed by RT-PCR followed by Sanger sequencing. In this work, we summarize a comprehensive spectrum of SEC23B variants, describe nine new CDA II cases accounting for six previously unreported variants, and discuss innovative therapeutic approaches for CDA II.This work was supported by NEOTEC grant SNEO-20191246 from Spanish CDTI to C.T., RETOS COLABORACION grant RTC2019-007074-1 from: MCIN/AEI/10.13039/501100011033 from Spanish Ministry of Science and Innovation (MICINN) to C.T. and M.S.; ARETHA grant PID2021-122436OB-I00 funded by MCIN/AEI/10.13039/501100011033 to M.S.; RTI-2018-101735-B-I100 from MCIN/AEI/10.13039/501100011033/ERDF “A way to make Europe” from the Spanish Ministry of Science and Innovation (MICINN) to M.S. M.M.M. is supported by a Marie Curie Fellowship from the European Commission under Horizon 2020 Framework Program Project: 894737. G.H. is supported by funds provided by the APU and ADISCON patient associations. L.R.-C. holds an FI-AGAUR predoctoral fellowship (2020FI-B00038) from Generalitat de Catalunya. X.F.-C. is partially supported by funds provided by the grant RTI-2018-101735-B-I100 from MCIN/AEI/10.13039/501100011033/ERDF “A way to make Europe”. V.V. was supported by funds provided by APU and ADISCON patient associations and UIC postdoctoral scholarship; she is currently supported by funds provided by RETOS COLABORACION grant RTC2019-007074-1 from MCIN/AEI/10.13039/501100011033 from Spanish Ministry of Science and Innovation (MICINN)

Radio observations of the merging galaxy cluster system Abell 3391-Abell 3395

The pre-merging system of galaxy clusters Abell 3391-Abell 3395 located at a mean redshift of 0.053 has been observed at 1 GHz in an ASKAP/EMU Early Science observation as well as in X-rays with eROSITA. The projected separation of the X-ray peaks of the two clusters is $\sim$50$'$ or $\sim$ 3.1 Mpc. Here we present an inventory of interesting radio sources in this field around this cluster merger. While the eROSITA observations provide clear indications of a bridge of thermal gas between the clusters, neither ASKAP nor MWA observations show any diffuse radio emission coinciding with the X-ray bridge. We derive an upper limit on the radio emissivity in the bridge region of $\langle J \rangle_{1\,{\rm GHz}}< 1.2 \times 10^{-44} {\rm W}\, {\rm Hz}^{-1} {\rm m}^{-3}$. A non-detection of diffuse radio emission in the X-ray bridge between these two clusters has implications for particle-acceleration mechanisms in cosmological large-scale structure. We also report extended or otherwise noteworthy radio sources in the 30 deg$^2$ field around Abell 3391-Abell 3395. We identified 20 Giant Radio Galaxies, plus 7 candidates, with linear projected sizes greater than 1 Mpc. The sky density of field radio galaxies with largest linear sizes of $>0.7$ Mpc is $\approx 1.7$ deg$^{-2}$, three times higher than previously reported. We find no evidence for a cosmological evolution of the population of Giant Radio Galaxies. Moreover, we find seven candidates for cluster radio relics and radio halos.Comment: Astronomy & Astrophysics, in pres

Imported arboviral infections in Italy, July 2014-October 2015: A National Reference Laboratory report

BACKGROUND: Imported cases of infections due to Dengue (DENV) and Chikungunya (CHIKV) viruses and, more recently, Zika virus (ZIKV) are commonly reported among travelers returning from endemic regions. In areas where potentially competent vectors are present, the risk of autochthonous transmission of these vector-borne pathogens is relatively high. Laboratory surveillance is crucial to rapidly detect imported cases in order to reduce the risk of transmission. This study describes the laboratory activity performed by the National Reference Laboratory for Arboviruses (NRLA) at the Italian National Institute of Health in the period from July 2014 to October 2015. METHODS: Samples from 180 patients visited/hospitalized with a suspected DENV/CHIKV/ZIKV infection were sent to the NRLA from several Italian Hospitals and from Regional Reference Laboratories for Arboviruses, in agreement with the National Plan on human surveillance of vector-borne diseases. Both serological (ELISA IgM test and Plaque Reduction Neutralization Test-PRNT) and molecular assays (Real Time PCR tests, RT-PCR plus nested PCR and sequencing of positive samples) were performed. RESULTS: DENV infection was the most frequently diagnosed (80 confirmed/probable cases), and all four genotypes were detected. However, an increase in imported CHIKV cases (41 confirmed/probable cases) was observed, along with the detection of the first ZIKV cases (4 confirmed cases), as a consequence of the recent spread of both CHIKV and ZIKV in the Americas. CONCLUSIONS: Main diagnostic issues highlighted in our study are sensitivity limitations of molecular tests, and the importance of PRNT to confirm serological results for differential diagnosis of Arboviruses. The continuous evaluation of diagnostic strategy, and the implementation of laboratories networks involved in surveillance activities is essential to ensure correct diagnosis, and to improve the preparedness for a rapid and proper identification of viral threats

High Levels of Exosomes Expressing CD63 and Caveolin-1 in Plasma of Melanoma Patients

BACKGROUND: Metastatic melanoma is an untreatable cancer lacking reliable and non-invasive markers of disease progression. Exosomes are small vesicles secreted by normal as well as tumor cells. Human tumor-derived exosomes are involved in malignant progression and we evaluated the presence of exosomes in plasma of melanoma patients as a potential tool for cancer screening and follow-up. METHODOLOGY/PRINCIPAL FINDINGS: We designed an in-house sandwich ELISA (Exotest) to capture and quantify exosomes in plasma based on expression of housekeeping proteins (CD63 and Rab-5b) and a tumor-associated marker (caveolin-1). Western blot and flow cytometry analysis of exosomes were used to confirm the Exotest-based findings. The Exotest allowed sensitive detection and quantification of exosomes purified from human tumor cell culture supernatants and plasma from SCID mice engrafted with human melanoma. Plasma levels of exosomes in melanoma-engrafted SCID mice correlated to tumor size. We evaluated the levels of plasma exosomes expressing CD63 and caveolin-1 in melanoma patients (n = 90) and healthy donors (n = 58). Consistently, plasma exosomes expressing CD63 (504+/-315) or caveolin-1 (619+/-310) were significantly increased in melanoma patients as compared to healthy donors (223+/-125 and 228+/-102, respectively). While the Exotest for CD63+ plasma exosomes had limited sensitivity (43%) the Exotest for detection of caveolin-1+ plasma exosomes showed a higher sensitivity (68%). Moreover, caveolin-1+ plasma exosomes were significantly increased with respect to CD63+ exosomes in the patients group. CONCLUSIONS/SIGNIFICANCE: We describe a new non-invasive assay allowing detection and quantification of human exosomes in plasma of melanoma patients. Our results suggest that the Exotest for detection of plasma exosomes carrying tumor-associated antigens may represent a novel tool for clinical management of cancer patients

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements