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Found 37769 matches. Displaying 1451-1460
Gedman G, Haase B, Durieux G, Biegler MT, Fedrigo O, Jarvis ED
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As above, so below: Whole transcriptome profiling demonstrates strong molecular similarities between avian dorsal and ventral pallial subdivisions

JOURNAL OF COMPARATIVE NEUROLOGY 2021 AUG; 529(12):3222-3246
Over the last two decades, beginning with the Avian Brain Nomenclature Forum in 2000, major revisions have been made to our understanding of the organization and nomenclature of the avian brain. However, there are still unresolved questions on avian pallial organization, particularly whether the cells above the vestigial ventricle represent distinct populations to those below it or similar populations. To test these two hypotheses, we profiled the transcriptomes of the major avian pallial subdivisions dorsal and ventral to the vestigial ventricle boundary using RNA sequencing and a new zebra finch genome assembly containing about 22,000 annotated, complete genes. We found that the transcriptomes of neural populations above and below the ventricle were remarkably similar. Each subdivision in dorsal pallium (Wulst) had a corresponding molecular counterpart in the ventral pallium (dorsal ventricular ridge). In turn, each corresponding subdivision exhibited shared gene co-expression modules that contained gene sets enriched in functional specializations, such as anatomical structure development, synaptic transmission, signaling, and neurogenesis. These findings are more in line with the continuum hypothesis of avian brain subdivision organization above and below the vestigial ventricle space, with the pallium as a whole consisting of four major cell populations (intercalated pallium, mesopallium, hyper-nidopallium, and arcopallium) instead of seven (hyperpallium apicale, interstitial hyperpallium apicale, intercalated hyperpallium, hyperpallium densocellare, mesopallium, nidopallium, and arcopallium). We suggest adopting a more streamlined hierarchical naming system that reflects the robust similarities in gene expression, neural connectivity motifs, and function. These findings have important implications for our understanding of overall vertebrate brain evolution.
Biegler MT, Cantin LJ, Scarano DL, Jarvis ED
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Controlling for activity-dependent genes and behavioral states is critical for determining brain relationships within and across species

JOURNAL OF COMPARATIVE NEUROLOGY 2021 AUG; 529(12):3206-3221
The genetic profile of vertebrate pallia has long driven debate on homology across distantly related clades. Based on an expression profile of the orphan nuclear receptor NR4A2 in mouse and chicken brains, Puelles et al. (The Journal of Comparative Neurology, 2016, 524, 665-703) concluded that the avian lateral mesopallium is homologous to the mammalian claustrum, and the medial mesopallium homologous to the insula cortex. They argued that their findings contradict conclusions by Jarvis et al. (The Journal of Comparative Neurology, 2013, 521, 3614-3665) and Chen et al. (The Journal of Comparative Neurology, 2013, 521, 3666-3701) that the hyperpallium densocellare is instead a mesopallium cell population, and by Suzuki and Hirata (Frontiers in Neuroanatomy, 2014, 8, 783) that the avian mesopallium is homologous to mammalian cortical layers 2/3. Here, we find that NR4A2 is an activity-dependent gene and cannot be used to determine brain organization or species relationships without considering behavioral state. Activity-dependent NR4A2 expression has been previously demonstrated in the rodent brain, with the highest induction occurring within the claustrum, amygdala, deep and superficial cortical layers, and hippocampus. In the zebra finch, we find that NR4A2 is constitutively expressed in the arcopallium, but induced in parts of the mesopallium, and in sparse cells within the hyperpallium, depending on animal stimulus or behavioral state. Basal and induced NR4A2 expression patterns do not discount the previously named avian hyperpallium densocellare as dorsal mesopallium and conflict with proposed homology between the avian mesopallium and mammalian claustrum/insula at the exclusion of other brain regions. Broadly, these findings highlight the importance of controlling for behavioral state and neural activity to genetically define brain cell population relationships within and across species.
Chen CC, Chen BR, Wang YN, Curman P, Beilinson HA, Brecht RM, Liu CC, Farrell RJ, de Juan-Sanz J, Charbonnier LM, Kajimura S, Ryan TA, Schatz DG, Chatila TA, Wikstrom JD, Tyler JK, Sleckman BP
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Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity is required for V(D)J recombination

JOURNAL OF EXPERIMENTAL MEDICINE 2021 AUG 2; 218(8):? Article e20201708
A whole-genome CRISPR/Cas9 screen identified ATP2A2, the gene encoding the Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) 2 protein, as being important for V(D)J recombination. SERCAs are ER transmembrane proteins that pump Ca2+ from the cytosol into the ER lumen to maintain the ER Ca2+ reservoir and regulate cytosolic Ca2+-dependent processes. In preB cells, loss of SERCA2 leads to reduced V(D)J recombination kinetics due to diminished RAG-mediated DNA cleavage. SERCA2 deficiency in B cells leads to increased expression of SERCA3, and combined loss of SERCA2 and SERCA3 results in decreased ER Ca2+ levels, increased cytosolic Ca2+ levels, reduction in RAG1 and RAG2 gene expression, and a profound block in V(D)J recombination. Mice with B cells deficient in SERCA2 and humans with Darier disease, caused by heterozygous ATP2A2 mutations, have reduced numbers of mature B cells. We conclude that SERCA proteins modulate intracellular Ca2+ levels to regulate RAG1 and RAG2 gene expression and V(D)J recombination and that defects in SERCA functions cause lymphopenia.
Sacramento CQ, Fintelman-Rodrigues N, Temerozo JR, Da Silva ADD, Dias SDG, da Silva CD, Ferreira AC, Mattos M, Pao CRR, de Freitas CS, Soares VC, Hoelz LVB, Fernandes TVA, Branco FSC, Bastos MM, Boechat N, Saraiva FB, Ferreira MA, Jockusch S, Wang XT, Tao CAJ, Chien MC, Xie W, Patel D, Garzia A, Tuschl T, Russo JJ, Rajoli RKR, Pedrosa CSG, Vitoria G, Souza LRQ, Goto-Silva L, Guimaraes MZ, Rehen SK, Owen A, Bozza FA, Bou-Habib DC, Ju JY, Bozza PT, Souza TML
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In vitro antiviral activity of the anti-HCV drugs daclatasvir and sofosbuvir against SARS-CoV-2, the aetiological agent of COVID-19

JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY 2021 JUL; 76(7):1874-1885
Background: Current approaches of drug repurposing against COVID-19 have not proven overwhelmingly successful and the SARS-CoV-2 pandemic continues to cause major global mortality. SARS-CoV-2 nsp12, its RNA polymerase, shares homology in the nucleotide uptake channel with the HCV orthologue enzyme NS5B. Besides, HCV enzyme NS5A has pleiotropic activities, such as RNA binding, that are shared with various SARS-CoV-2 proteins. Thus, anti-HCV NS5B and NS5A inhibitors, Like sofosbuvir and daclatasvir, respectively, could be endowed with anti-SARS-CoV-2 activity. Methods: SARS-CoV-2-infected Vero cells, HuH-7 cells, Calu-3 cells, neural stem cells and monocytes were used to investigate the effects of daclatasvir and sofosbuvir. In silico and cell-free based assays were performed with SARS-CoV-2 RNA and nsp12 to better comprehend the mechanism of inhibition of the investigated compounds. A physiologically based pharmacokinetic model was generated to estimate daclatasvir's dose and schedule to maximize the probability of success for COVID-19. Results: Daclatasvir inhibited SARS-CoV-2 replication in Vero, HuH-7 and Calu-3 cells, with potencies of 0.8, 0.6 and 1.1 mu M, respectively. Although Less potent than daclatasvir, sofosbuvir alone and combined with daclatasvir inhibited replication in Calu-3 cells. Sofosbuvir and daclatasvir prevented virus-induced neuronal apoptosis and release of cytokine storm-related inflammatory mediators, respectively. Sofosbuvir inhibited RNA synthesis by chain termination and daclatasvir targeted the folding of secondary RNA structures in the SARS-CoV-2 genome. Concentrations required for partial daclatasvir in vitro activity are achieved in plasma at C-max after administration of the approved dose to humans. Conclusions: Daclatasvir, alone or in combination with sofosbuvir, at higher doses than used against HCV, may be further fostered as an anti-COVID-19 therapy.
Loukeris M, Sanghai ZA, Vendome J, Hendrickson WA, Kloss B, Mancia F
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Fine Sampling of Sequence Space for Membrane Protein Structural Biology

JOURNAL OF MOLECULAR BIOLOGY 2021 JUL 23; 433(15):? Article 167055
We describe an enhancement of traditional genomics-based approaches to improve the success of structure determination of membrane proteins. Following a broad screen of sequence space to identify initial expression-positive targets, we employ a second step to select orthologs with closely related sequences to these hits. We demonstrate that a greater percentage of these latter targets express well and are stable in detergent, increasing the likelihood of identifying candidates that will ultimately yield structural information. (C) 2021 Elsevier Ltd. All rights reserved.
Lilic M, Darst SA, Campbell EA
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Structural basis of transcriptional activation by the Mycobacterium tuberculosis intrinsic antibiotic-resistance transcription factor WhiB7

MOLECULAR CELL 2021 JUL 15; 81(14):2875-2886.e5
In pathogenic mycobacteria, transcriptional responses to antibiotics result in induced antibiotic resistance. WhiB7 belongs to the Actinobacteria-specific family of Fe-S-containing transcription factors and plays a crucial role in inducible antibiotic resistance in mycobacteria. Here, we present cryoelectron microscopy structures of Mycobacterium tuberculosis transcriptional regulatory complexes comprising RNA polymerase sigma(A)-holoenzyme, global regulators CarD and RbpA, and WhiB7, bound to a WhiB7-regulated promoter. The structures reveal how WhiB7 interacts with sigma(A)-holoenzyme while simultaneously interacting with an AT-rich sequence element via its AT-hook. Evidently, AT-hooks, rare elements in bacteria yet prevalent in eukaryotes, bind to target AT-rich DNA sequences similarly to the nuclear chromosome binding proteins. Unexpectedly, a subset of particles contained a WhiB7-stabilized closed promoter complex, revealing this intermediate's structure, and we apply kinetic modeling and biochemical assays to rationalize how WhiB7 activates transcription. Altogether, our work presents a comprehensive view of how WhiB7 serves to activate gene expression leading to antibiotic resistance.
Felix S, Handem S, Nunes S, Paulo AC, Candeias C, Valente C, Simoes AS, Almeida ST, Tavares DA, Brito-Avo A, de Lencastre H, Sa-Leao R
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Impact of private use of the 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal carriage among Portuguese children living in urban and rural regions

VACCINE 2021 JUL 22; 39(32):4524-4533
In Portugal, the 13-valent pneumococcal conjugate vaccine (PCV13) was commercially available between 2010 and 2015, following a decade of private use of PCV7. We evaluated changes on serotype distribution and antimicrobial susceptibility of pneumococci carried by children living in two regions of Portugal (one urban and one rural). Three epidemiological periods were defined: pre-PCV13 (2009-2010), early-PCV13 (2011-2012), and late-PCV13 (2015-2016). Nasopharyngeal samples (n = 4,232) were obtained from children 0-6 years old attending day-care centers. Private use of PCVs was very high in both regions (>75%). Pneumococcal carriage remained stable and high over time (62.1%, 62.4% and 61.6% (p = 0.909) in the urban region; and 59.8%, 62.8%, 59.5% (p = 0.543) in the rural region). Carriage of PCV7 serotypes remained low (5.3%, 7.8% and 4.3% in the urban region; and 2.5%, 3.7% and 4.8% in the rural region). Carriage of PCV13 serotypes not targeted by PCV7 decreased in both the urban (16.4%, 7.3%, and 1.6%; p < 0.001) and rural regions (13.2%, 7.8%, and 1.9%; p < 0.001). This decline was mostly attributable to serotype 19A (14.1%, 4.4% and 1.3% in the urban region; and 11.1%, 3.6% and 0.8% in the rural region, both p < 0.001). Serotype 3 declined over time in the urban region (10.1%, 4.4%, 0.8%; p < 0.001) and had no obvious trend in the rural region (4.2%, 6.7%, 2.4%; p = 0.505). Serotype 6C decreased in both regions while serotypes 11D, 15A/B/C, 16F, 21, 22F, 23A/B, 24F, 35F, and NT were the most prevalent in the late-PCV13 period. Intermediate resistance to penicillin and non-susceptibility to erythromycin decreased significantly in both regions (19.5%, 13.3%, and 9.3%; and 25.4%, 25.9%, and 13.4%; both p < 0.001, respectively in the urban region; and 12.4%, 11.1%, and 2.8% (p < 0.001); and 15.3%, 14.7%, and 9.2% (p = 0.037), respectively, in the rural region). In conclusion, private use of PCV13 led to significant changes on the pneumococcal population carried by children in Portugal. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
Wong HH, Seet SH, Maier M, Gurel A, Traspas RM, Lee C, Zhang S, Talim B, Loh AYT, Chia CY, Teoh TS, Sng D, Rensvold J, Unal S, Shishkova E, Cepni E, Nathan FM, Sirota FL, Liang C, Yarali N, Simsek-Kiper PO, Mitani T, Ceylaner S, Arman-Bilir O, Mbarek H, Gumruk F, Efthymiou S, Cimen DU, Georgiadou D, Sotiropoulou K, Houlden H, Paul F, Pehlivan D, Laine C, Chai GL, Ali NA, Choo SC, Keng SS, Boisson B, Yilmaz E, Xue SF, Coon JJ, Ly TTN, Gilani N, Hasbini D, Kayserili H, Zaki MS, Isfort RJ, Ordonez N, Tripolszki K, Bauer P, Rezaei N, Seyedpour S, Khotaei GT, Bascom CC, Maroofian R, Chaabouni M, Alsubhi A, Eyaid W, Isikay S, Gleeson JG, Lupski JR, Casanova JL, Pagliarini DJ, Akarsu NA, Maurer-Stroh S, Cetinkaya A, Bertoli-Avella A, Mathuru AS, Ho LN, Bard FA, Reversade B
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Loss of C2orf69 defines a fatal autoinflammatory syndrome in humans and zebrafish that evokes a glycogen-storage-associated mitochondriopathy

AMERICAN JOURNAL OF HUMAN GENETICS 2021 JUL 1; 108(7):1301-1317
Human C2orf69 is an evolutionarily conserved gene whose function is unknown. Here, we report eight unrelated families from which 20 children presented with a fatal syndrome consisting of severe autoinflammation and progredient leukoencephalopathy with recurrent seizures; 12 of these subjects, whose DNA was available, segregated homozygous loss-of-function C2orf69 variants. C2ORF69 bears homology to esterase enzymes, and orthologs can be found in most eukaryotic genomes, including that of unicellular phytoplankton. We found that endogenous C2ORF69 (1) is loosely bound to mitochondria, (2) affects mitochondrial membrane potential and oxidative respiration in cultured neurons, and (3) controls the levels of the glycogen branching enzyme 1 (GBE1) consistent with a glycogen-storage-associated mitochondriopathy. We show that CRISPR-Cas9-mediated inactivation of zebrafish C2orf69 results in lethality by 8 months of age due to spontaneous epileptic seizures, which is preceded by persistent brain inflammation. Collectively, our results delineate an autoinflammatory Mendelian disorder of C2orf69 deficiency that disrupts the development/homeostasis of the immune and central nervous systems.
Blachere NE, Hacisuleyman E, Darnell RB
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Vaccine Breakthrough Infections with SARS-CoV-2 Variants REPLY

NEW ENGLAND JOURNAL OF MEDICINE 2021 JUL 8; 385(2):?
Demiroz D, Platanitis E, Bryant M, Fischer P, Prchal-Murphy M, Lercher A, Lassnig C, Baccarini M, Muller M, Bergthaler A, Sexl V, Dolezal M, Decker T
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Listeria monocytogenes infection rewires host metabolism with regulatory input from type I interferons

PLOS PATHOGENS 2021 JUL; 17(7):? Article e1009697
Listeria monocytogenes (L. monocytogenes) is a food-borne bacterial pathogen. Innate immunity to L. monocytogenes is profoundly affected by type I interferons (IFN-I). Here we investigated host metabolism in L. monocytogenes-infected mice and its potential control by IFN-I. Accordingly, we used animals lacking either the IFN-I receptor (IFNAR) or IRF9, a subunit of ISGF3, the master regulator of IFN-I-induced genes. Transcriptomes and metabolite profiles showed that L. monocytogenes infection induces metabolic rewiring of the liver. This affects various metabolic pathways including fatty acid (FA) metabolism and oxidative phosphorylation and is partially dependent on IFN-I signaling. Livers and macrophages from Ifnar1(-/-) mice employ increased glutaminolysis in an IRF9-independent manner, possibly to readjust TCA metabolite levels due to reduced FA oxidation. Moreover, FA oxidation inhibition provides protection from L. monocytogenes infection, explaining part of the protection of Irf9(-/-) and Ifnar1(-/-) mice. Our findings define a role of IFN-I in metabolic regulation during L. monocytogenes infection. Metabolic differences between Irf9(-/-) and Ifnar1(-/-) mice may underlie the different susceptibility of these mice against lethal infection with L. monocytogenes. Author summary Many immune cells undergo metabolic remodeling following encounters with cytokines or pathogenic insults. This is essential to perform their downstream effector functions and eradicate the infectious agents. Drug-mediated interference with metabolic remodeling can have a strong impact on clearance of the pathogen. Here we describe metabolic changes occurring during Listeria monocytogenes (L. monocytogenes) infection of murine hosts. Infected animals show profound changes of liver metabolism that include increased glycolysis, alterations in TCA cycle metabolites and the ratio of free versus conjugated fatty acids. Similar to what has been described during viral infections, type I interferons (IFN-I), a family of cytokines produced during L. monocytogenes infections, are involved in the import of fatty acids (FA) into the mitochondria to generate energy via oxidative phosphorylation. Accordingly, in the absence of IFN-I signals, the cells oxidize less FAs and this might help the cells better fight the infection. We also speculate that infected cells instead boost glutamine utilization to supply their energy need. Our work describes metabolic rewiring that takes place during L. monocytogenes infection and the contribution of IFN-I signaling. Our study improves the understanding of listeriosis and has the potential to help us discover new drug targets against L. monocytogenes and viruses that induce IFN-I response.