bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracellular Staphylococcus aureus persisters upon antibiotic exposure
Authors: Peyrusson Frédéric , Varet Hugo , Nguyen Tiep Khac , Legendre Rachel , Sismeiro Odile , Coppée Jean-Yves , Wolz Christiane , Tenson Tanel , Van Bambeke Françoise 
Published: May 2020

AbstractBacterial persister cells are phenotypic variants that exhibit a transient non-growing state and antibiotic tolerance. Here, we provide in vitro evidence ofStaphylococcus aureuspersisters within infected host cells. We show that the bacteria surviving antibiotic treatment within host cells are persisters, displaying biphasic killing and reaching a uniformly non-responsive, non-dividing state when followed at the single-cell level. This phenotype is stable but reversible upon antibiotic removal. IntracellularS. aureuspersisters remain metabolically active but display an altered transcriptomic profile consistent with activation of stress responses, including the stringent response as well as cell wall stress, SOS and heat shock responses. These changes are associated with multidrug tolerance after exposure to a single antibiotic. We hypothesize that intracellularS. aureuspersisters may constitute a reservoir for relapsing infection and could contribute to therapeutic failures.
TALPID3 and ANKRD26 selectively orchestrate FBF1 localization and cilia gating
Authors: Yan Hao , Chen Chuan , Chen Huicheng , Hong Hui , Huang Yan , Ling Kun , Hu Jinghua , Wei Qing 
Published: May 2020

AbstractTransition fibers (TFs) regulate cilia gating and make the primary cilium a distinct functional entity. However, molecular insights into the biogenesis of a functional cilia gate remain elusive. In a forward genetic screen in Caenorhabditis elegans, we uncover that TALP-3, a homolog of the Joubert syndrome protein TALPID3, is a TF-associated component. Genetic analysis reveals that TALP-3 coordinates with ANKR-26, the homolog of ANKRD26, to orchestrate proper cilia gating. Mechanistically, TALP-3 and ANKR-26 form a complex with key gating component DYF-19, the homolog of FBF1. Co-depletion of TALP-3 and ANKR-26 specifically impairs the recruitment of DYF-19 to TFs. Interestingly, in mammalian cells, TALPID3 and ANKRD26 also play a conserved role in coordinating the recruitment of FBF1 to TFs. We thus report a conserved protein module that specifically regulates the functional component of the ciliary gate and suggest a correlation between defective gating and ciliopathy pathogenesis.
A PKB-SPEG signaling nexus links insulin resistance with diabetic cardiomyopathy by regulating calcium homeostasis
Authors: Quan Chao , Du Qian , Li Min , Wang Ruizhen , Ouyang Qian , Su Shu , Zhu Sangsang , Chen Qiaoli , Sheng Yang , Chen Liang , Wang Hong , Campbell David G. , MacKintosh Carol , Yang Zhongzhou , Ouyang Kunfu , Wang Hong Yu , Chen Shuai 
Published: May 2020

AbstractDiabetic cardiomyopathy is a progressive disease in diabetic patients, and myocardial insulin resistance contributes to its pathogenesis through incompletely-defined mechanisms. Striated muscle preferentially expressed protein kinase (SPEG) has two kinase-domains and is a critical cardiac regulator. Here we show that SPEG is phosphorylated on Ser2461/Ser2462/Thr2463 by protein kinase B (PKB) in response to insulin. PKB-mediated phosphorylation of SPEG activates its second kinase-domain, which in turn phosphorylates sarcoplasmic/endoplasmic reticulum calcium-ATPase 2a (SERCA2a) and accelerates calcium re-uptake into the SR. Cardiac-specific deletion of PKBα/β or a high fat diet inhibits insulin-induced phosphorylation of SPEG and SERCA2a, prolongs SR re-uptake of calcium, and impairs cardiac function. Mice bearing a Speg3A mutation to prevent its phosphorylation by PKB display cardiac dysfunction. Importantly, the Speg3A mutation impairs SERCA2a phosphorylation and calcium re-uptake into the SR. Collectively, these data demonstrate that insulin resistance impairs this PKB-SPEG-SERCA2a signal axis, which contributes to the development of diabetic cardiomyopathy.
Increased O-GlcNAcylation rapidly decreases GABAAR currents in hippocampus but depresses neuronal output
Authors: Stewart L. T. , Abiraman K. , Chatham J. C. , McMahon L. L. 
Published: May 2020

AbstractO-GlcNAcylation, a post-translational modification involving O-linkage of β-N-acetylglucosamine to Ser/Thr residues on target proteins, is increasingly recognized as a critical regulator of synaptic function. Enzymes that catalyze O-GlcNAcylation are found at both presynaptic and postsynaptic sites, and O-GlcNAcylated proteins localize to synaptosomes. An acute increase in O-GlcNAcylation can affect neuronal communication by inducing long-term depression (LTD) of excitatory transmission at hippocampal CA3-CA1 synapses, as well as suppressing hyperexcitable circuits in vitro and in vivo. Despite these findings, to date, no studies have directly examined how O-GlcNAcylation modulates the efficacy of inhibitory neurotransmission. Here we show an acute increase in O-GlcNAc dampens GABAergic currents onto principal cells in rodent hippocampus likely through a postsynaptic mechanism, and has a variable effect on the excitation/inhibition balance. The overall effect of increased O-GlcNAc is reduced synaptically-driven spike probability via synaptic depression and decreased intrinsic excitability. Our results position O-GlcNAcylation as a novel regulator of the overall excitation/inhibition balance and neuronal output.
Intra-Day and Inter-Day Reliability of Measurements of the electromyographic signal on masseter and temporal muscles in patients with Down syndrome
Authors: Giannasi Lilian Chrystiane , Politti Fabiano , Dutra Marignês T. S. , Tenguan Vera L. S. , Silva Gabriela R. C. , Mancilha Gabriela P. , Silva Daniel Batista da , Oliveira Luis Vicente Franco , Oliveira Claudia Santos , Amorim Jose B. O. , Salgado Miguel Angel Castillo , Gomes Mônica F. 
Published: May 2020

AbstractThe aim of the present study was to evaluate intra-day (test) and inter-day (re-test) reliability of surface electromyography (sEMG) signals of the masseter and temporal muscles in patients with Down syndrome (DS). We determined the reliability of sEMG variables in 33 patients with DS. EMG signals were recorded at rest as well as during maximum voluntary clenching and maximum habitual intercuspation (MHI). The signals were analyzed considering the amplitude in the root mean square (RMS), mean frequency (MNF), median frequency (MDF) and approximate entropy (ApEn). The intraclass correlation (ICC2,1) for the three trials recorded during MHI in the two sessions (test and retest) revealed excellent intra-session and inter-session reliability (ICC2,1 = 0.76 to 0.97) for all sEMG variables and muscles. In the rest position, excellent reliability was found for RMS and ApEn (ICC2,1 = 0.75 to 1.00) and good to excellent reliability was found for MDF and MNF (ICC2,1 = 0.64 to 0.93). The intra-session (test) and inter-session (re-test) analyses demonstrated the reliability of nonlinear sEMG variables of the masticatory muscles in adults with Down Syndrome.
Enhanced cell density cultivation and rapid expression-screening of recombinant Pichia pastoris clones in microscale
Authors: Kaushik Neha , Lamminmäki Urpo , Khanna Navin , Batra Gaurav 
Published: May 2020

AbstractCultivation of yeast Pichia pastoris in the microtiter plate, for optimisation of culture conditions, and expression screening of transformants has gained significance in recent years. However, in the microtiter plate, it has been challenging to attain cell densities similar to well-aerated shake-flask culture, due to the poor mixing resulting in oxygen limitation. To solve this problem, we investigated the influence of multiple cultivation parameters on P. pastoris cell growth, including the architecture of 96-deepwell plate (96-DWP), shaking throw diameter, shaking frequency, culture volume/well, and media composition. In the optimised conditions, a cell density of OD600 ~50 (dry cell weight ~13 g/L) with >99% cell viability was achieved in the casamino acids supplemented buffered-minimal-media in 300 to 1000 μl culture volume/well. We have devised a simplified method for coating of the culture supernatant on the polystyrene surface for immunoassay. Clones for secretory expression of envelope domain III of dengue virus serotype-1 under the control of inducible and constitutive promoter were screened using the developed method. Described microscale cultivation strategy can be used for rapid high-throughput screening of P. pastoris clones, media optimization, and high-throughput recombinant protein production. The knowledge gained through this work may also be applied, to other suspension cultures, with some modifications.
Conductive Highly Filled Suspensions for an Electrochemical Dispensing Approach to Pattern Full-Area Thin Metal Layers by Physical Vapour Deposition
Authors: Gensowski Katharina , Tepner Sebastian , Schweigert Sebastian , Clement Florian , Kamp Mathias , Pospischil Maximilian , Bartsch Jonas 
Published: May 2020

AbstractThis paper presents a systematic approach for the development of highly filled suspensions used for an electrochemical dispensing approach. Electrochemical dispensing is an alternative structuring process to locally pattern PVD full-area thin metal layers with the goal to create contacts on solar cells or circuit boards by anodic metal dissolution. Achieving a narrow patterned line width requires a dispensing paste with a high yield stress, a small particle size distribution and a good electrical conductivity. Therefore this work focuses on the formulation and characterization of dispensing pastes in terms of their rheological and electrical properties and their particle size distribution. Furthermore, the printing performance is evaluated in dispensing experiments. In this study, samples with a yield stress above 5000 Pa and an average particle size below 0.4 µm were produced, resulting in dispensed line widths below 100 µm with a high aspect ratio above 0.6. The lack of electrical conductivity was solved by adding KCl solution to the paste, which will add to the ionic conductivity of the NaNO3 basis paste formulation. With this approach, printed line widths down to 115 µm and etched line widths below 90 µm at high aspect ratio were achieved on 50 nm aluminum layers.
DNA:RNA hybrid G-quadruplex formation upstream of transcription start site
Authors: Zhang Jia-yu , Xia Ye , Hao Yu-hua , Tan Zheng 
Published: May 2020

AbstractBioinformatic analysis reveals an enrichment of putative DNA:RNA hybrid G-quadruplex-forming sequences (PHQS) on both sides of the transcription start sites (TSSs) in the genome of warm-blooded animals, suggesting a positive selection of PHQSs in evolution and functional role of DNA:RNA hybrid G-quadruplexes (HQs) in transcription. The formation of HQs downstream of TSS in transcribed DNA has been documented under in vitro conditions; however, it is still not known if such HQs can form at the upstream side of TSSs. In this study, we report that such HQs can form in transcription in DNA with two to three guanine tracts if RNA carrying the required number of G-tracts is supplied. We also show that the formation of such HQs is dependent on the negative supercoiling generated by RNA polymerases. These results suggest that HQs may also form at the upstream side of TSSs in vivo and play a role in transcription since the two requirements are satisfied in cells.
Human pluripotent stem cell-based models suggest preadipocyte senescence as a possible cause of metabolic complications of Werner and Bloom Syndromes
Authors: Goh Kim Jee , Chen Jian-Hua , Rocha Nuno , Semple Robert K. 
Published: May 2020

AbstractWerner Syndrome (WS) and Bloom Syndrome (BS) are disorders of DNA damage repair caused by biallelic disruption of the WRN or BLM DNA helicases respectively. Both are commonly associated with insulin resistant diabetes, usually accompanied by dyslipidemia and fatty liver, as seen in lipodystrophies. In keeping with this, progressive reduction of subcutaneous adipose tissue is commonly observed. To interrogate the underlying cause of adipose tissue dysfunction in these syndromes, CRISPR/Cas9 genome editing was used to generate human pluripotent stem cell (hPSC) lacking either functional WRN or BLM helicase. No deleterious effects were observed in WRN−/− or BLM−/− embryonic stem cells, however upon their differentiation into adipocyte precursors (AP), premature senescence emerged, impairing later stages of adipogenesis. The resulting adipocytes were also found to be senescent, with increased levels of senescent markers and senescence-associated secretory phenotype (SASP) components. SASP components initiate and reinforce senescence in adjacent cells, which is likely to create a positive feedback loop of cellular senescence within the adipocyte precursor compartment, as demonstrated in normal ageing. Such a scenario could progressively attenuate adipose mass and function, giving rise to “lipodystrophy-like” insulin resistance. Further assessment of pharmacological senolytic strategies are warranted to mitigate this component of Werner and Bloom syndromes.
Singularity of a relativistic vortex beam and proper relativistic observables
Authors: Han Yeong Deok , Choi Taeseung , Cho Sam Young 
Published: May 2020

AbstractWe have studied the phase singularity of relativistic vortex beams for two sets of relativistic operators using circulation. One set includes new spin and orbital angular momentum (OAM) operators, which are derived from the parity-extended Poincaré group, and the other set consists of the (usual) Dirac spin and OAM operators. The first set predicts the same singularity in the circulation as in the case of nonrelativistic vortex beams. On the other hand, the second set anticipates that the singularity of the circulation is spin-orientation-dependent and can disappear, especially for a relativistic paraxial electron beam with spin parallel to the propagating direction. These contradistinctive predictions suggest that a relativistic electron beam experiment with spin-polarized electrons could for the first time answer a long-standing fundamental question, i.e., what are the proper relativistic observables, raised from the beginning of relativistic quantum mechanics following the discovery of the Dirac equation.
Identification, characterization and expression analysis of calmodulin and calmodulin-like proteins in Solanum pennellii
Authors: Shi Jinyan , Du Xiangge 
Published: May 2020

AbstractIn plants, the calmodulin (CaM) proteins is an important calcium-binding protein, which play a crucial role in both regulating plant growth and development, as well as in the resistance mechanisms to various biotic and abiotic stresses. However, there is limited knowledge available on the CaM family functions in Solanum pennellii, a wild tomato species utilized as a genetic resource for cultivated tomatoes. In this study, 6 CaM (SpCaM) and 45 CaM-like (SpCML) genes from Solanum pennellii were selected for bioinformatics analysis to obtain insights into their phylogenetic relationships, gene structures, conserved motifs, chromosomal locations, and promoters. The results showed that the 6 SpCaM proteins contained 4 EF-hand domains each, and the 45 SpCML proteins had 2-4 EF-hand domains. The 51 CaM and CaM-like genes contained different intron/exon patterns and they were unevenly distributed across the 12 chromosomes of S. pennellii. The results of the analysis of the conserved motifs and promoter cis-regulatory elements also indicated that these proteins were involved in the responses to biotic and abiotic stresses. qRT-PCR analysis indicated that the SpCaM and SpCML genes had broad expression patterns in abiotic stress conditions and with hormone treatments, in different tissues. The findings of this study will be important for further investigations of the calcium signal transduction mechanisms under stress conditions and lay a theoretical foundation for further exploration of the molecular mechanisms of plant resistance.
Discordance of peripheral artery disease diagnosis using exercise transcutaneous oxygen pressure measurement and post-exercise ankle-brachial index
Authors: Mahé G. , Catillon F. , Tollenaere Q. , Jéhannin P. , Guilcher A. , Le Pabic E. , Lesager G. , Omarjee L. , Le Faucheur A. 
Published: May 2020

AbstractIn patients with exertional limb symptoms and normal ankle-brachial index (ABI) at rest, exercise testing can be used to diagnose lower extremity arterial disease (LEAD). Post-exercise ABI decrease or Exercise transcutaneous oxygen pressure measurement (Exercise-TcPO2) can be used to diagnose LEAD. Objectives were (i) to assess the agreement between both methods (ii) to define the variables associated with the discordance, and (iii) to present results of healthy subjects. In this prospective cross-sectional study, patients with exertional limb symptoms and normal rest ABI were consecutively included. ABI was measured at rest and after standardized exercise protocol as well as Exercise-TcPO2. A kappa coefficient with a 95% confidence interval was used to assess the agreement between the two methods. Logistic regression analysis was performed to outline variables potentially responsible for discordance. Ninety-six patients were included. The agreement between the tests was weak with a k value of 0.23 [0.04–0.41]. Logistic regression analysis found that a medical history of lower extremity arterial stenting (odds ratio 5.85[1.68–20.44]) and age (odds ratio 1.06[1.01–1.11]) were the main cause of discordance. This study suggests that post-exercise ABI and Exercise-TcPO2 cannot be used interchangeably for the diagnosis of LEAD in patients with exertional symptoms and normal rest ABI.
Visualization of spatial and temporal temperature distributions with magnetic particle imaging for liver tumor ablation therapy
Authors: Salamon J. , Dieckhoff J. , Kaul M. G. , Jung C. , Adam G. , Möddel M. , Knopp T. , Draack S. , Ludwig F. , Ittrich H. 
Published: May 2020

AbstractTemperature-resolved magnetic particle imaging (MPI) represents a promising tool for medical imaging applications. In this study an approach based on a single calibration measurement was applied for highlighting the potential of MPI for monitoring of temperatures during thermal ablation of liver tumors. For this purpose, liver tissue and liver tumor phantoms embedding different superparamagnetic iron oxide nanoparticles (SPION) were prepared, locally heated up to 70 °C and recorded with MPI. Optimal temperature MPI SPIONs and a corresponding linear model for temperature calculation were determined. The temporal and spatial temperature distributions were compared with infrared (IR) camera results yielding quantitative agreements with a mean absolute deviation of 1 °C despite mismatches in boundary areas.
The limitations of targeting MEK signalling in Glioblastoma therapy
Authors: Selvasaravanan Karthika D. , Wiederspohn Nicole , Hadzalic Amina , Strobel Hannah , Payer Christel , Schuster Andrea , Karpel-Massler Georg , Siegelin Markus D. , Halatsch Marc-Eric , Debatin Klaus-Michael , Westhoff Mike-Andrew 
Published: May 2020

AbstractGlioblastoma (GB) is a highly aggressive, difficult to treat brain tumour. Successful treatment, consisting of maximal safe tumour de-bulking, followed by radiotherapy and treatment with the alkylating agent Temozolomide (TMZ), can extend patient survival to approximately 15 months. Combination treatments based on the inhibition of the PI3K pathway, which is the most frequently activated signalling cascade in GB, have so far only shown limited therapeutic success. Here, we use the clinically approved MEK inhibitor Trametinib to investigate its potential use in managing GB. Trametinib has a strong anti-proliferative effect on established GB cell lines, stem cell-like cells and their differentiated progeny and while it does not enhance anti-proliferative and cell death-inducing properties of the standard treatment, i.e. exposure to radiation or TMZ, neither does MEK inhibition block their effectiveness. However, upon MEK inhibition some cell populations appear to favour cell-substrate interactions in a sprouting assay and become more invasive in the Chorioallantoic Membrane assay, which assesses cell penetration into an organic membrane. While this increased invasion can be modulated by additional inhibition of the PI3K signalling cascade, there is no apparent benefit of blocking MEK compared to targeting PI3K.
Novel Combinatorial Regimen of Garcinol and Curcuminoids for Non-alcoholic Steatohepatitis (NASH) in Mice
Authors: Majeed Muhammed , Majeed Shaheen , Nagabhushanam Kalyanam , Lawrence Lincy , Mundkur Lakshmi 
Published: May 2020

AbstractNon-alcoholic steatohepatitis (NASH) is a progressive form of Non-alcoholic fatty liver disease (NAFLD), a chronic liver disease with a significant unmet clinical need. In this study, we examined the protective effects of Garcinia indica extract standardized to contain 20% w/w of Garcinol (GIE) and 95% Curcuminoids w/w from Curcuma longa (Curcuminoids) in a Stelic animal model (STAM) of NASH. The STAM mice developed steatosis, hepatocyte ballooning, and inflammation, which were significantly reduced by the combination of GIE and Curcuminoids, resulting in a lower NAFLD activity score. The treatment reduced fibrosis as observed by Sirius red staining, liver hydroxyproline content and mRNA levels of TGF- β and collagen in the liver. Immunostaining with alpha-smooth muscle actin (α SMA) revealed a significant reduction in hepatic stellate cells. Intriguingly, the combination regimen markedly decreased the mRNA levels of MCP1 and CRP and both mRNA and protein levels of TNF-α. NF-kB, reduced the hepatic and circulating FGF21 levels and altered the nonenzymatic (glutathione) and enzymatic antioxidant markers (Glutathione peroxidase, and superoxide dismutase). Our results suggest that the combination of GIE and Curcuminoids can reduce the severity of NASH by reducing steatosis, fibrosis, oxidative stress, and inflammation. The results suggest that the combinatorial regimen could be an effective supplement to prevent the progression of liver steatosis to inflammation and fibrosis in NASH.
Osteogenic impact of pro-apoptotic caspase inhibitors in MC3T3-E1 cells
Authors: Kratochvílová Adéla , Veselá Barbora , Ledvina Vojtěch , Švandová Eva , Klepárník Karel , Dadáková Kateřina , Beneš Petr , Matalová Eva 
Published: May 2020

AbstractCaspases are proteases traditionally associated with inflammation and cell death. Recently, they have also been shown to modulate cell proliferation and differentiation. The aim of the current research was to search for osteogenic molecules affected by caspase inhibition and to specify the individual caspases critical for these effects with a focus on proapoptotic caspases: caspase-2, -3, -6, -7, -8 and -9. Along with osteocalcin (Ocn), general caspase inhibition significantly decreased the expression of the Phex gene in differentiated MC3T3-E1 cells. The inhibition of individual caspases indicated that caspase-8 is a major contributor to the modification of Ocn and Phex expression. Caspase-2 and-6 had effects on Ocn and caspase-6 had an effect on Phex. These data confirm and expand the current knowledge about the nonapoptotic roles of caspases and the effect of their pharmacological inhibition on the osteogenic potential of osteoblastic cells.