bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aire-dependent transcripts escape H3K36me3 and Raver2 induced alternative splicing to sustain central immune tolerance
Authors: Padonou Francine , Gonzalez Virginie , Jmari Nada , Maslovskaja Julia , Kisand Kai , Peterson Pärt , Irla Magali , Giraud Matthieu 
Published: April 2021

AbstractAire allows medullary thymic epithelial cells (mTECs) to express and present a large number of self-antigens for central tolerance. Although mTECs express a high diversity of self-antigen splice isoforms, the extent and regulation of alternative splicing events (ASEs) included in their transcripts, notably in those induced by Aire, is unknown. Unexpectedly, and in contrast to Aire-neutral genes, we found that the Aire-sensitive genes exhibit in Aire-positive and negative mTECs, a weak inclusion of ASEs, with about a quarter present in peripheral tissues being excluded from the thymus. We identified Raver2, as a splicing-related factor overrepresented in mTECs and dependent on H3K36me3 marks. We discovered that both Raver2 and methylation of H3K36 promoted ASE inclusion for Aire-neutral genes, leaving Aire-sensitive genes unaffected. Profiling of H3K36me3 revealed its depletion at Aire-sensitive genes, supporting a mechanism, whose setup precedes Aire’s expression and by which Aire-sensitive genes exhibit weak ASE inclusion through the escape of Raver2’s effect. Lack of ASEs in Aire-induced transcripts highlights a role for regulatory T cells in controlling the incomplete Aire-dependent negative selection.
In vivoengineered B cells retain memory and secrete high titers of anti-HIV antibodies in mice
Authors: Nahmad A. D. , Lazzarotto C. R. , Zelikson N. , Kustin T. , Tenuta M. , Huang D. , Reuveni I. , Horovitz-Fried M. , Dotan I. , Rosin-Arbesfeld R. , Nemazee D. , Voss J.E. , Stern A. , Tsai S. Q. , Barzel A. 
Published: April 2021

ABSTRACTAs a potential single-shot HIV therapy, transplanted engineered B cells allow robust secretion of broadly neutralizing antibodies (bNAbs). However,ex vivoengineering of autologous B cells is expensive and requires specialized facilities, while allogeneic B cell therapy necessitates MHC compatibility. Here, we developin vivoB cell engineering, by injecting two adeno associated viral vectors, one coding for saCas9 and another coding for a bNAb. Following immunizations, we demonstrate memory retention and bNAb secretion at neutralizing titers. We observed minimal CRISPR/Cas9 off-target cleavage, using unbiased CHANGE-Seq analysis, while on-target cleavage at undesired tissues is reduced by expressing saCas9 from a B cell specific promoter.In vivoB cell engineering is thus a safe, potent and scalable method for expressing desired antibodies against HIV and beyond.One sentence summaryB cells can be engineeredin vivoto robustly secrete anti-HIV bNAbs in a safe, durable and scalable manner.
Exploration of the Ixodes ricinus virosphere unveils an extensive virus diversity including novel Coltiviruses and other reoviruses
Authors: Vanmechelen Bert , Merino Michelle , Vergote Valentijn , Laenen Lies , Thijssen Marijn , Martí-Carreras Joan , Claerebout Edwin , Maes Piet 
Published: April 2021

AbstractRecent metagenomics studies have revealed several tick species to host a variety of previously undiscovered RNA viruses. Ixodes ricinus, which is known to be a vector for many viral, bacterial and protozoan pathogens, is the most prevalent tick species in Europe. For this study, we decided to investigate the virosphere of Belgian I. ricinus ticks. High-throughput sequencing of tick pools collected from six different sampling sites revealed the presence of viruses belonging to many different viral orders and families, including Mononegavirales, Bunyavirales, Partitiviridae and Reoviridae. Of particular interest was the detection of several new reoviruses, two of which cluster together with members of the genus Coltivirus. This includes a new strain of Eyach virus, a known causative agent of tick-borne encephalitis. All genome segments of this new strain are highly similar to those of previously published Eyach virus genomes, except for the fourth segment, encoding VP4, which is markedly more dissimilar, potentially indicating the occurrence of a genetic reassortment. Further PCR-based screening of over 230 tick pools for 14 selected viruses showed that most viruses could be found in all six sampling sites, indicating the wide spread of these viruses throughout the Belgian tick population. Taken together, these results illustrate the role of ticks as important virus reservoirs, highlighting the need for adequate tick control measures.
Combined oncolytic adenovirus carrying MnSOD and mK5 genes both regulated by survivin promoter has synergistic inhibitory effect on gastric cancer
Authors: Liu Shanshan , Hu JinQing , Gu Jinfa , Ni Aimin , Tang Wenhao , Liu Xinyuan 
Published: April 2021

AbstractGastric cancer (GC) is one of the major causes of cancer related mortality. The use of oncolytic virus for cancer gene-virotherapy is a new approach for the treatment of human cancers. In this study, a novelSurvivinpromoter driven recombinant oncolytic adenovirus carryingmK5orMnSODgene was constructed, which was modified after deletion of E1B gene. Human plasminogen Kringle 5 mutant (mK5) and manganese superoxide dismutase (MnSOD) are both potential tumor suppressor genes. To construct Ad-Surp-mK5and Ad-Surp-MnSODoncolytic adenovirus, we hypothesized that the combination of the two viruses would enhance the therapeutic efficacy of GC as compared to the virus alone. The results of thein vitroexperiments revealed that the combination of adenovirus carryingmK5andMnSODgene exhibited stronger cytotoxicity to GC cell lines as compared to the virus alone, Additionally, the virus could selectively kill cancer cells and human somatic cells. Cell staining, flow cytometry and western blot analysis showed that the combination of two adenovirus containing therapeutic genes could promote the apoptosis of cancer cells.In vivoexperiments further verified that Ad-Surp-mK5in combination with Ad-Surp-MnSODexhibited significant inhibitory effect on the growth of GC tumor xenograft as compared to the virus alone, and no significant difference was observed in the body weight of treatment and the normal mice. In conclusion, the combination of our two newly constructed recombinant oncolytic adenovirus containingmK5orMnSODtherapeutic genes could significantly inhibit gastric cancer growth by inducing apoptosis, suggestive of its potential for GC therapy.
Identification of an inhibitory pocket in falcilysin provides a new avenue for malaria drug development
Authors: Wirjanata Grennady , Lin Jianqing , Dziekan Jerzy Michal , El Sahili Abbas , Chung Zara , Tjia Seth , Zulkifli Nur Elyza Binte , Boentoro Josephine , Tham Roy , Jia Lai Si , Go Ka Diam , Yu Han , Partridge Anthony , Olsen David , Prabhu Nayana , Sobota Radoslaw M , Nordlund Pär , Lescar Julien , Bozdech Zbynek 
Published: April 2021

AbstractDespite their widespread use, our understanding of how many antiparasitic drugs work remains limited. We used mass-spectrometry based cellular thermal shift assay (MS-CETSA) to identify possible protein targets of several malaria drugs and drug candidates. We found that falcilysin (FLN) is a common target for several quinoline drugs including chloroquine and mefloquine, as well as drug candidates MK-4815, MMV000848 and MMV665806. At pH 7.5, these compounds all inhibit FLN proteolytic activity with IC50values ranging from 1.6 to 67.9 µM. Their interaction with FLN was systematically probed by isothermal titration calorimetry and X-ray crystallography, revealing a shared hydrophobic pocket in the catalytic chamber of the enzyme. Characterization of transgenic cell lines with depleted FLN expression demonstrated statistically significant increases in susceptibility towards chloroquine, mefloquine, MK-4815 and MMV000848. Taken together, our findings point to a multimodal mechanism of action for several commonly used anti-malaria drugs. Importantly, a common allosteric pocket of FLN appears amenable to inhibition, providing a structural basis to guide the development of novel drugs against malaria.
Lipid mediator profile of burn wound healing: Acellular cod fish skin grafts promote the formation of EPA and DHA derived lipid mediators during the first seven days
Authors: Kotronoulas Aristotelis , Karvelsson Sigurður Trausti , Heijink Marieke , Stone Randolph , Giera Martin , Rolfsson Ottar 
Published: April 2021

AbstractThe use of acellular fish skin grafts (FSG) for the treatment of burn wounds is becoming more common due to its beneficial wound healing properties. In our previous study we demonstarted that FSG is a scaffold biomaterial that is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) conjugated to phosphatidylcholines. Here we investigated whether EPA and DHA derived lipid mediators are influenced during the healing of burn wounds treated with FSG. Deep partial and full thickness burn wounds (DPT and FT respectively) were created on Yorkshire pigs (n=4). DPT were treated with either FSG or fetal bovine dermis while FT were treated either with FSG or cadaver skin initially and followed by a split thickness skin graft. Punch biopsies were collected on days 7, 14, 21, 28 and 60 and analysed in respect of changes to approximately 45 derivatives of EPA, DHA, arachidonic acid (AA), and linoleic acid (LA) employing UPLC-MS/MS methodology. Several EPA and DHA derivatives, including 18-HEPE and 17-HDHA, were significantly higher on day 7 in the DPT when treated with FSG. A similar but non-significant trend was observed for the FT. In addition, prostaglandin F2α and its 15-keto derivative (AA pathway) as well as 13-HODE and 13-HOTrE (LA pathway) were significantly lower in the FSG treated FT. The results suggest that the use of FSG in burn wound treatment can alter the formation of EPA and DHA mono hydroxylated lipid mediators in comparison to other grafts of mammalian origin. The differences observed during the first seven days after treatment indicates that FSG affects the early stages of wound healing.HighlightsThis is the first study to investigate whether omega-3 rich biomaterial such as fish skin graft can affect the lipidome of burn wound healingThe study monitors the formation of lipid mediators during 60 days of burn wound healingThis is the first study to show an increase in the formation of mono-hydroxylated derivatives of EPA and DHA after seven days of treatment with fish skin graftThe study showed significantly decreased formation of lipid mediators involved in pain modulation in wounds treated with fish skin graft
Traveling waves in the prefrontal cortex during working memory
Authors: Bhattacharya Sayak , Brincat Scott L. , Lundqvist Mikael , Miller Earl K. 
Published: April 2021

AbstractNeural oscillations are evident across cortex but their spatial structure is not well-explored. Are oscillations stationary or do they form “traveling waves”, i.e., spatially organized patterns whose peaks and troughs move sequentially across cortex? Here, we show that oscillations in the prefrontal cortex (PFC) organized as traveling waves in the theta (4-8Hz), alpha (8-12Hz) and beta (12-30Hz) bands. Some traveling waves were planar but most rotated. The waves were modulated during performance of a working memory task. During baseline conditions, waves flowed bidirectionally along a specific axis of orientation. Waves in different frequency bands could travel in different directions. During task performance, there was an increase in waves in one direction over the other, especially in the beta band.Author SummaryWe found that oscillations in the prefrontal cortex form “traveling waves”. Traveling waves are spatially extended patterns in which aligned peaks of activity move sequentially across the cortical surface. Some traveling waves were planar but most rotated. The prefrontal cortex is important for working memory. The traveling waves changed when monkeys performed a working memory task. There was an increase in waves in one direction over the other, especially in the beta band. Traveling waves can serve specific functions. For example, they help maintain network status and help control timing relationships between spikes. Given their functional advantages, a greater understanding of traveling waves should lead to a greater understanding of cortical function.
Pathogen invasion-dependent tissue reservoirs and plasmid-encoded antibiotic degradation boost plasmid spread in the gut
Authors: Bakkeren Erik , Herter Joana A. , Huisman Jana S. , Steiger Yves , Gül Ersin , Newson Joshua P.M. , Brachmann Alexander O. , Piel Jörn , Regoes Roland R. , Bonhoeffer Sebastian , Diard Médéric , Hardt Wolf-Dietrich 
Published: April 2021

AbstractMany plasmids encode antibiotic resistance genes. Through conjugation, plasmids can be rapidly disseminated. Previous work identified gut-luminal donor/recipient blooms and tissue-lodged plasmid-bearing persister cells of the enteric pathogenSalmonella entericaserovar Typhimurium (S.Tm) that survive antibiotic-therapy in host tissues, as factors promoting plasmid dissemination amongEnterobacteriaceae. However, the buildup of tissue reservoirs and their contribution to plasmid spread await experimental demonstration. Here, we asked if re-seeding-plasmid acquisition-invasion cycles byS.Tm could serve to diversify tissue-lodged plasmid reservoirs, and thereby promote plasmid spread. Starting with intraperitoneal mouse infections, we demonstrate thatS.Tm cells re-seeding the gut lumen initiate clonal expansion. ESBL plasmid-encoded gut luminal antibiotic degradation by donors can foster recipient survival under beta-lactam antibiotic treatment, enhancing transconjugant formation upon re-seeding.S.Tm transconjugants can subsequently re-enter host tissues introducing the new plasmid into the tissue-lodged reservoir. Population dynamics analyses pinpoint recipient migration into the gut lumen as rate-limiting for plasmid transfer dynamics in our model. Priority effects may be a limiting factor for reservoir formation in host tissues. Overall, our proof-of-principle data indicates that luminal antibiotic degradation and shuttling between the gut lumen and tissue-resident reservoirs can promote the accumulation and spread of plasmids within a host over time.
Human endogenous oxytocin and its neural correlates show adaptive responses to social touch based on recent social context
Authors: Handlin Linda , Novembre Giovanni , Lindholm Heléne , Kämpe Robin , Paul Elisabeth , Morrison India 
Published: April 2021

AbstractBoth oxytocin (OT) and touch are key mediators of social attachment. In rodents, tactile stimulation elicits endogenous release of OT, potentially facilitating attachment and other forms of prosocial behavior, yet the relationship between endogenous OT and neural modulation remains unexplored in humans. Using serial sampling of plasma hormone levels during functional neuroimaging across two successive social interactions, we show that contextual circumstances of social touch facilitate or inhibit not only current hormonal and brain responses, but also calibratelaterresponses. Namely, touch from a male to his female romantic partner enhanced subsequent OT release for touch from an unfamiliar stranger, yet OT responses to partner touch were dampened following stranger touch. Hypothalamus and dorsal raphe activation reflected plasma OT changes during the initial interaction. In the subsequent social interaction, time- and context-dependent OT changes modulated precuneus and parietal-temporal cortex pathways, including a region of medial prefrontal cortex that also covaried with plasma cortisol. These findings demonstrate that hormonal neuromodulation during successive human social interactions is adaptive to social context, and point to mechanisms that flexibly calibrate receptivity in social encounters.
BIOMODULATORY EFFECT OF LOW INTENSITY LASER (830 nm.) IN NEURAL CELLS 9L/lacZ
Authors: Zabeu Antonieta Marques Caldeira , Carvalho Isabel Chaves Silva , Soares Cristina Pacheco , da Silva Newton Soares 
Published: April 2021

AbstractBackgroundCurrently, research is advancing low intensity laser (LIL) in central nervous system cells to available the benefits of this therapy in neurological disorders, and research seeks to establish the best LIL protocol in biological processes of neuronal tissue with the different energy wavelengths(λ), and exposure time (s) and frequency(Hz). The aim of this study is to check the biomodulatory effects of the LIL in neural cell culture.MethodsDiode laser λ = 830 nm, power of 40 mW, continuous mode, applied in the cells lineage 9L/lacZ, with energy densities of 0.5, 1.5 and 3.0 J/cm2. Analysed 24 hours after irradiation, the results of the cell viability show the difference between the control and treated groups.ResultsIn the occurrence of apoptosis, no significant manifestation was observed between the control group compared with the irradiated one (P = 0.9956); there was a significant difference between apoptosis and death by necrosis has been between the control and treated groups (P <0.001). In the comet assay there was not difference.ConclusionsWith the aim of evaluating whether LIL promotes early activation of programmed cell death, of 9L/lacZ cells, in the proposed parameters of LIL, we observed that promoted an increase in the number of neural cells, highlighting the action of biomodulation; LIL did not promote the activation of apoptosis and did not any indication of DNA deterioration in the comet assay. The results of this study are indicative that the near infrared laser has a positive interaction with neuronal cells.
Structural basis for human T-cell leukemia virus type 1 Gag targeting to the plasma membrane for assembly
Authors: Herrmann Dominik , Zhou Lynne W. , Hanson Heather M. , Willkomm Nora A. , Mansky Louis M. , Saad Jamil S. 
Published: April 2021

ABSTRACTDuring the late phase of retroviral replication, the virally encoded Gag polyprotein is targeted to the plasma membrane (PM) for assembly. Gag–PM binding is mediated by the N-terminal matrix (MA) domain of Gag. For many retroviruses, Gag binding to the PM was found to be dependent on phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. However, it was shown that for human T-cell leukemia virus type 1 (HTLV-1), Gag binding to membranes is less dependent on PI(4,5)P2, suggesting that other factors may modulate Gag assembly. To elucidate the mechanism by which HTLV-1 Gag binds to the PM, we employed NMR techniques to solve the structure of unmyristoylated MA (myr(–)MA) and to characterize its interactions with lipids and liposomes. The MA structure consists of four α-helices and unstructured N- and C-termini. We show that myr(–)MA binds to PI(4,5)P2via the polar head and that myr(–)MA binding to inositol phosphates (IPs) is significantly enhanced by increasing the number of phosphate groups on the inositol ring, indicating that the MA–IP binding is governed by charge–charge interactions. The IP binding site was mapped to a well-defined basic patch formed by lysine and arginine residues. Using a sensitive NMR-based liposome binding assay, we show that myr(–)MA binding to membranes is significantly enhanced by phosphatidylserine (PS). Confocal microscopy data show that Gag is localized to the inner leaflet of the PM of infected cells, while the Gag G2A mutant, lacking myristoylation, is diffuse and cytoplasmic. These findings advance our understanding of a key mechanism in retroviral assembly.
Local administration of bicuculline into the ventrolateral and medial preoptic nuclei modifies sleep and maternal behavior in lactating rats
Authors: Benedetto Luciana , Rivas Mayda , Peña Florencia , Serantes Diego , Ferreira Annabel , Torterolo Pablo 
Published: April 2021

AbstractThe preoptic area (POA) is a brain structure classically involved in a wide variety of animal behavior including sleep and maternal care. In the current study, we evaluate the specific effect of disinhibition of two specific regions of the POA, the medial POA nucleus (mPOA) and the ventrolateral POA area (VLPO) on sleep and maternal behavior in lactating rats. For this purpose, mother rats on postpartum day 1 (PPD1) were implanted for polysomnographic recordings and with bilateral cannulae either in the mPOA or in the VLPO. The rats were tested for sleep and maternal behavior on PPD4-8 after the infusion of the GABA-A antagonist, bicuculline (0, 10 or 30 ng/0.2 µl/side). Infusion of bicuculline into the mPOA augmented retrieving and nest building behaviors and reduced both nursing and milk ejections but had almost no effect on sleep. When bicuculine was microinjected into the VLPO, the rats significantly increase the number of retrievings and mouthings and reduced the nursing time without changes in milk ejections, which was associated with an increase in wakefulness and a reduction in light sleep.Our results show that disinhibition of the mPOA, a key area in the control of maternal behavior, increased active maternal behaviors and reduced nursing without affecting wakefulness or sleep time. In contrast, the enhancement of some active maternal behaviors when the drug was infused into the VLPO, a sleep-promoting area, with a concomitant increase in wakefulness suggests that mother rats devote this additional waking time in the active maternal care of the pups. We hypothesize that maternal behavior changes after bicuculine microinjection into the VLPO is caused by a reduction in the sleep drive, rather than a direct effect on maternal behavior.
Conformational clamping by a membrane ligand activates the EphA2 receptor
Authors: Westerfield Justin M. , Sahoo Amita R. , Alves Daiane S. , Grau Brayan , Cameron Alayna , Maxwell Mikayla , Schuster Jennifer A. , Souza Paulo C. T. , Mingarro Ismael , Buck Matthias , Barrera Francisco N. 
Published: April 2021

AbstractThe EphA2 receptor is a promising drug target for cancer treatment, since EphA2 activation can inhibit metastasis and tumor progression. It has been recently described that the TYPE7 peptide activates EphA2 using a novel mechanism that involves binding to the single transmembrane domain of the receptor. TYPE7 is a conditional transmembrane (TM) ligand, which only inserts into membranes at neutral pH in the presence of the TM region of EphA2. However, how membrane interactions can activate EphA2 is not known. We systematically altered the sequence of TYPE7 to identify the binding motif used to activate EphA2. With the resulting six peptides, we performed biophysical and cell migration assays that identified a new potent peptide variant. We also performed a mutational screen that determined the helical interface that mediates dimerization of the TM domain of EphA2 in cells. These results, together with molecular dynamic simulations, allowed to elucidate the molecular mechanism that TYPE7 uses to activate EphA2, where the membrane peptide acts as a molecular clamp that wraps around the TM dimer of the receptor. We propose that this binding mode stabilizes the active conformation of EphA2. Our data, additionally, provide clues into the properties that TM ligands need to have in order to achieve activation of membrane receptors.